TITLE: Biotechnology: Plant Protection from Nonviral Agents
PUBLICATION DATE: January, 1993
ENTRY DATE: Feb, 1994
EXPIRATION DATE: None
UPDATE FREQUENCY: As needed
CONTACT: Biotechnology Information Center(biotech@nalusda.gov)
National Agricultural Library
DOCUMENT TYPE: Text
DOCUMENT SIZE: 417k, approx. 232 pp.

ISSN: 1052-5378

United States Department of Agriculture
National Agricultural Library
10301 Baltimore Blvd.
Beltsville, Maryland  20705-2351

Biotechnology:  Plant Protection from Nonviral Agents
January 1991 - December 1992

QB 93-13

Quick Bibliography Series:  QB 93-13
Updates QB 91-82

284 citations from AGRICOLA

Daniel Cabirac and Robert Warmbrodt
Biotechnology Information Center

January 1993
National Agricultural Library Cataloging Record:

Cabirac, Daniel
  Biotechnology, plant protection from non-viral agents.
  (Quick bibliography series ; 93-13)
  1. Plants, Protection of--Bibliography. I. Warmbrodt, Robert
  D. II. Title.
aZ5071.N3 no.93-13
AGRICOLA


SEARCH STRATEGY

Set   Items    Description
---   -----    -----------
S1    8755     BIOTECH? OR BIOENGINEER? OR RECOMBINANT()DNA OR
               MICROMANIPULAT? OR TRANSGEN?
               ORGENETIC?()ENGINEER?

S2    6894     (GENE OR GENES OR GENETIC? OR GENOM? OR
               CHROMOSOM? OR DNA OR RNA)(4N)(CHANG? OR ALTER?
               OR INSERT? OR MANIPULAT? OR TRANSFER? OR
               TRANSFORM? OR RECOMBIN? OR SPLIC?)

S3    15720    PLASTID? OR COSMID? OR PLASMID? OR PHAGE? OR
               MONOCLONAL()ANTIBOD? OR HYBRIDOMA? OR VECTOR?
               OR TRANSPOSON?

S4    27466    S1 OR S2 OR S3

S5    10245    S4 AND PY=1989:1992

S6    717      S5 AND (SH=F800 OR SH=F820 OR SH=F822 OR
               SH=F830 OR SH=F831 OR SH=F832 OR SH=840 OR
               SH=F850 OR SH=F851)

S7    687      S6 NOT (VIRUS? OR VIRAL)/DE

S8    314      S6 AND PY=1991:1992

S9    306      S7 AND PY=1991:19921                                   NAL Call. No.: QH442.A1G4
The a mating-type alleles of Ustilago maydis are idiomorphs.
Froeliger, E.H.; Leong, S.A.
Amsterdam : Elsevier Science Publishers; 1991.
Gene v. 100: p. 113-122; 1991.  Includes references.

Language:  English

Descriptors: Ustilago zeae; Alleles; Genetic transformation;
Dna; Restriction mapping

Abstract:  Two unlinked incompatibility loci, a and b, control
mating, pathogenicity, and sexual development in Ustilago
maydis, a fungal pathogen of corn. Fusion of nonpathogenic
haploid cells occurs when alleles of the a locus differ;
fusion products that differ at the b locus will be pathogenic
and complete sexual development. The two alleles of the a
locus have been cloned. The a2 allele was isolated by
exploiting the close linkage of the a locus to the genetic
marker panI. Several cosmids from a clonal a2 mating-type
library allowed, via DNA-mediated transformation, an al mating
type, panl-1 auxotrophic recipient to grow prototrophically on
medium lacking pantothenic acid. Cosmids containing functional
a2 mating-type regions were identified by their ability to
confer a2 mating behavior to the a1 recipient strain. The al
allele was isolated from a plasmid library using DNA from the
a2 region as a hybridization probe. The isolated clones
contain al or a2 mating-type specificity as demonstrated by a
plate mating assay, by pathogenicity tests on corn, and by
gene replacement experiments. The a1 and a2 mating-type clones
contain nonhomologous DNA segments that are flanked by similar
nucleotide (nt) sequences. Restriction fragments containing a
mating-type function are embedded within the nonhomologous DNA
segments. U. maydis contains a single copy of either the al or
a2 mating-type sequence within each haploid genome. This
structural organization demonstrates that the a mating-type
alleles of U. maydis are idiomorphs sensu Metzenberg and Glass
(1990), nt sequences mapping to the same genetic locus that
share no obvious evolutionary relationship.


2                                   NAL Call. No.: QH442.A1G4
Acquisition of mitochondrial DNA by a transformation vector
for Ustilago violacea.
Bej, A.K.; Perlin, M.H.
Amsterdam : Elsevier Science Publishers; 1991.
Gene v. 98 (1): p. 135-140; 1991.  Includes references.

Language:  English

Descriptors: Ustilago violacea; Escherichia coli; Genetic
transformation; Vectors; Mitochondrial  DNA; Plasmids;
Restriction mapping

Abstract:  Plasmid pUCH1 is a 5.2-kb pUC18 construct bearing
the hygB gene fused to a promoter from Cochliobolus
heterostrophus. Haploid cells of the basidiomycete, Ustilago
violacea, were transformed with this plasmid. In addition to
multiple integrations of plasmid sequences into U. violacea
nuclear DNA, vector sequences independent of the nuclear
genome were indicated by Southern-blot analysis using all or
part of pUCH1 as a probe. Hybridization also revealed intact
pUCH1 and several larger derivatives in satellite bands from
CsC1-bis-benzamide gradients of whole cellular DNA and in DNA
from purified mitochondria [mitochondrial (mt) DNA
preparations] of transformed U. violacea; circular DNAs
consistent with the sizes of DNAs in these satellite bands
were seen in electron microscope analyses of the same mt DNA
preparations as well. The plasmids could be detected in mt DNA
preparations even after 30 generations of transformant growth
under selective pressure. Transformation of Escherichia coli
by these mt DNA preparations produced bacterial transformants
bearing intact pUCH1, as well as several pUCH1 derivatives,
including pUCH2, an approx. 8.0-kb plasmid. A 2.5-kb EcoRI
fragment from pUCH2 showed only weak hybridization with pUCH1.
This unique fragment did hybridize strongly with mt DNA from
untransformed U. violacea. This derivative thus appears to
have acquired mt sequences from U. violacea.


3                                     NAL Call. No.: 500 N21P
Activity of the Agrobacterium T-DNA transfer machinery is
affected by virB gene products.
Ward, J.E. Jr; Dale, E.M.; Binns, A.N.
Washington, D.C. : The Academy; 1991 Oct15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (20): p. 9350-9354; 1991 Oct15. 
Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Crown gall; Disease
resistance; Gene expression; Genetic transformation;
Agrobacterium tumefaciens; Dna; Plasmids; Strains; Transfer
factor; Virulence

Abstract:  The oriT (origin of transfer) sequence and mob
(mobilization) genes of plasmid RSF1010 can functionally
replace transfer DNA (T-DNA) borders to generate an RSF1010
intermediate transferable to plants through activities of the
tumor-inducing (Ti)-plasmid virulence (vir) genes of
Agrobacterium tumefaciens. Because the Ti plasmid virB gene
products are hypothesized to form a membrane-localized T-DNA
transport apparatus, we investigated whether specific virB
genes were needed for RSF1010 transfer. Here we report that
transformation of Nicotiana tabacum leaf explants by an
RSF1010-derivative plasmid (pJW323) requires the essential
virulence genes virB9, virB10, and virB11, consistent with the
hypothesis that both the T-DNA and RSF1010 transfer
intermediates utilize the same transport machinery. Further,
while pJW323 is transferred into plant cells by Agrobacterium
strains harboring both pJW323 and pTiA6, the initiation of
crown gall tumors (i.e., T-DNA transfer) is greatly
suppressed. Coordinate overexpression of the virB9, virB10,
and virB11 gene products relieves pJW323-mediated oncogenic
suppression and restores tumorigenicity, but does not increase
the transfer frequency of pJW323 into plant cells. We propose
that the virB9, virB10, and virB11 gene products function
coordinately and stoichiometrically to enhance DNA transfer in
a fashion specific for the T-DNA intermediate.


4                                    NAL Call. No.: QK725.P54
Agrobacterium induced gall formation in lipoxygenase mutant
isolines of soybeans.
Bhatt, D.; Parrott, W.A.; Collins, G.B.; Hildebrand, D.F.
Berlin, W. Ger. : Springer International; 1991.
Plant cell reports v. 9 (11): p. 651-654; 1991.  Includes
references.

Language:  English

Descriptors: Glycine max; Agrobacterium tumefaciens; Genetic
transformation; Transgenics; Galls; Pathogenicity; Regulation;
Lipoxygenase; Enzyme activity; Mutants; Genetic variation

Abstract:  Agrobacterium-mediated transformation frequency is
very low with cells from some species such as soybeans.
Studies were conducted to investigate the Agrobacterium-
mediated transformation frequency in near-isogenic
lipoxygenase mutant lines of soybeans, since the high level of
lipoxygenase activity in soybean embryos might be expected to
affect interactions with Agrobacterium. The mutant line
lacking lipoxygenase 3 showed significantly greater frequency
of Agrobacterium-induced transformation than the other soybean
lines. Stages of soybean embryo development which showed
maximum differences in lipoxygenase 3 activity between mutant
and wild-type, also showed maximum differences in
transformation frequency. The increased transformation
frequency with the absence of lipoxygenase 3 was only seen
when both lipoxygenase 1 and 2 were present.


5                                   NAL Call. No.: QH442.A1G4
Agrobacterium rhizogenes lacZ-rolC gene expression in
Escherichia coli: detection of the product in transgenic
plants using RolC-specific antibodies. Oono, Y.; Satomi, T.;
Uchimiya, H.
Amsterdam : Elsevier Science Publishers; 1991.
Gene v. 104 (1): p. 95-98; 1991.  Includes references.

Language:  English

Descriptors: Agrobacterium rhizogenes; Genes; Gene expression;
Recombinant DNA; Nicotiana tabacum; Transgenics; Escherichia
coli; Plasmids

Abstract:  The rolC sequence of the Agrobacterium rhizogenes
Ri plasmid was fused in-frame to the 3' end of the lacZ gene
in plasmid pEX3. The fusion protein RolC-beta-galactosidase
was accumulated as insoluble inclusion bodies in Escherichia
coli. Antibodies were raised in rabbits against the fusion
protein. After affinity purification, RolC-specific antibodies
were found to react with a 22-kDa polypeptide prepared from
roots of transgenic tobacco plants possessing a rolC gene. The
result of differential centrifugation suggested that RolC is
present in the soluble fraction of transformed cells.


6                                    NAL Call. No.: 448.3 J82
Agrobacterium tumefaciens transfer extremely long T-DNAs by a
unidirectional mechanism.
Miranda, A.; Janssen, G.; Hodges, L.; Peralta, E.G.; Ream, W.
Washington, D.C. : American Society for Microbiology; 1992
Apr. Journal of bacteriology v. 174 (7): p. 2288-2297; 1992
Apr.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Dna; Plasmids;
Transfer

Abstract:  During crown gall tumorigenesis, part of the
Agrobacterium tumefaciens tumor-inducing (Ti) plasmid, the T-
DNA, integrates into plant DNA. Direct repeats define the left
and right ends of the T-DNA, but tumorigenesis requires only
the right-hand repeat. Virulence (vir) genes act in trans to
mobilize the T-DNA into plant cells. Transfer of T-DNA begins
when the VirD endonuclease cleaves within the right-hand
border repeat. Although the T-DNA right-border repeat promotes
T-DNA transmission best in its normal orientation, an inverted
right border exhibits reduced but significant activity. Two
models may account for this diminished tumorigenesis. The
right border may function bidirectionally, with strong-
activity only in its wild-type orientation, or it may promote
T-DNA transfer in a unidirectional manner such that, with an
inverted right border, transfer proceeds around the entire Ti
plasmid before reaching the T-DNA. To determine whether a
substantial portion of the Ti plasmid is transferred to plant
cells, as predicted by the unidirectional-transfer hypothesis,
we examined T-DNAs in tumors induced by strains containing a
Ti plasmid with a right border inverted with respect to the T-
DNA oncogenes. These tumors contained extremely long T-DNAs
corresponding to most or all of the Ti plasmid. To test
whether the right border can function bidirectionally, we
inserted T-DNAs with either a properly oriented or an inverted
right border into a specific site in the A. tumefaciens
chromosome. A border situated to transfer the oncogenes first
directed T-DNA transfer even from the bacterial chromosome,
whereas a border in the opposite (inverted) orientation did
not transfer the oncogenes to plant cells. Our results
indicate that the right-border repeat functions in a
unidirectional manner.


7                                    NAL Call. No.: 448.3 J82
The Agrobacterium tumefaciens vir gene transcriptional
activator virG is transcriptionally induced by acid pH and
other stress stimuli. Mantis, N.J.; Winans, S.C.
Washington, D.C. : American Society for Microbiology; 1992
Feb. Journal of bacteriology v. 174 (4): p. 1189-1196; 1992
Feb.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Genes; Proteins;
Stress; Pathogenesis; Ph

Abstract:  A set of Agrobacterium tumefaciens operons required
for pathogenesis is coordinately induced during plant
infection by the VirA and VirG proteins. The intracellular
concentration of VirG increases in response to acidic media,
and this response was proposed to be regulated at the level of
transcription at a promoter (P2) that resembles the
Escherichia coli heat shock promoters. To test this
hypothesis, we first constructed a virG-lacZ transcriptional
fusion. A strain containing this fusion had higher levels of
beta-galactosidase activity in acidic media than in media at
neutral pH. Second, primer extension analysis of virG
indicated that acidic media stimulated the transcription of
this promoter. To determine whether P2 is a member of a heat
shock-like regulon in A. tumefaciens, five agents that induce
E. coli heat shock genes were tested for their abilities to
induce a P2-lacZ fusion in A. tumefaciens. P2 was most
strongly induced by low pH, was moderately stimulated by CdCl2
or mitomycin C, and was slightly induced by alkaline pH or
ethanol. Heat shock or growth at high temperature did not
cause detectable induction of P2 as measured by beta-
galactosidase activity and primer extension analysis.
Induction by these treatments did not require any Ti plasmid-
encoded function or the chromosomally encoded RecA protein. We
also pulse-labeled cellular proteins after a shift to low pH
and detected several proteins whose synthesis was induced by
these conditions. We conclude that P2 is primarily induced by
acid pH and secondarily by certain other stimuli, each of
which is stressful to cell growth. This stress induction is at
least partly independent of the heat shock and SOS responses.


8                                    NAL Call. No.: 450 P5622
Agrobacterium vir-inducing activities of glycosylated
acetosyringone, acetovanillone, syringaldehyde and syringic
acid derivatives. Delmotte, F.M.; Delay, D.; Cizeau, J.;
Guerin, B.; Leple, J.C. Oxford : Pergamon Press; 1991.
Phytochemistry v. 30 (11): p. 3549-3552; 1991.  Includes
references.

Language:  English

Descriptors: Plant pathogenic bacteria; Agrobacterium
tumefaciens; Pathogenicity; Induction; Tumors; Syringic acid;
Derivatives; Vanillic acid; Glycosides; Genetic regulation;
Virulence; Gene expression

Abstract:  Expression of the Agrobacterium tumefaciens
virulence (vir) gene is known to be dependent on host plant
phenolic compounds. The A. tumefaciens strain A348 (psM358)
harbouring a virE::lacZ fusion plasmid was used to detect the
ability of 13 synthetic acetosyringone, acetovanillone,
syringaldehyde and syringic acid beta-glycosides to induce
virulence. The activity of the reporter beta-galactosidase was
detected by spectrofluorimetry using 4-methylumbelliferyl
beta-galactopyranoside as substrate. Acetosyringonyl beta-L-
fucopyranoside was the most active monoglycoside tested; even
at high concentration this compound was devoid of toxic
effects, However, monoglycosides were less active vir inducers
than free acetosyringone. In contrast, the beta-maltoside of
syringaldehyde showed higher activity than the free phenol at
high concentration. The activity of such glycosylated inducers
may be related to specific sugar receptors on the bacterial
cell surface.


9                                    NAL Call. No.: QH301.N32
Agrobacterium-mediated transformation of apple (Malus pumila
Mill). James, D.J.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 213-226;
1991.  In the series analytic: Woody plant biotechnology /
edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Literature review. 
Includes references.

Language:  English

Descriptors: Malus pumila; Genetic transformation;
Agrobacterium tumefaciens; Cultivars; Explants; Leaves;
Organogenesis; Rooting; Transgenics; Literature reviews


10                                   NAL Call. No.: 442.8 Z34
Analysis of a high frequency transformation system for
Ophiostoma ulmi, the causal agent of Dutch elm disease.
Royer, J.C.; Dewar, K.; Hubbes, M.; Horgen, P.A.
Berlin, W. Ger. : Springer International; 1991 Jan.
M G G : Molecular and general genetics v. 225 (1): p. 168-176.
ill; 1991 Jan. Includes references.

Language:  English

Descriptors: Ceratocystis ulmi; Genetic transformation; Direct 
DNAuptake; Protoplasts; Plasmids; Gene transfer; Reporter
genes; Hygromycin b; Drug resistance; Phosphotransferases;
Repetitive  DNA; Promoters; Southern blotting;
Electrophoresis; Mitosis

Abstract:  A transformation system for Ophiostoma ulmi
(Buism.) Nannf. was developed and analyzed. Protoplasts were
generated from actively budding yeastlike cells by digestion
with NovoZym 234 in MgSO4 after pretreatment with 2-
mercaptoethanol. Protoplast regeneration was most efficient
when 0.6 M sucrose was used as the osmoticum. Several plasmids
containing fusions between fungal promoters and a bacterial
gene for hygromycin phosphotransferase successfully
transformed O. ulmi to hygromycin resistance. One of these
vectors, pPS57, which contains a promoter for isopenicillin N
synthetase from Penicillium chrysogenum, consistently
conferred the greatest resistance to hygromycin. Linearization
of the vector and inclusion of 2-mercaptoethanol in the
transformation reaction resulted in enhanced transformation
efficiency. Approximately 4 X 10(3) transformants /microgram
DNA per 10(7) protoplasts were obtained using the optimized
procedure. Southern hybridization after alternating field and
standard electrophoresis suggested random insertion of tandem
repeats (some greater than 250 kb) into the fungal
chromosomes. Antibiotic resistance was stable through mitosis.
However, expression of the transforming DNA after meiosis was
highly variable.


11                                   NAL Call. No.: QK710.P62
Analysis of cis-regulatory elements involved in induction of a
tobacco PR-5 gene by virus infection.
Albrecht, H.; Rhee, M.D. van de; Bol, J.F.
Dordrecht : Kluwer Academic Publishers; 1992 Jan.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 18
(1): p. 155-158; 1992 Jan. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Tobacco mosaic tobamovirus;
Gene expression; Pathogenesis-related proteins; Genes;
Controlling elements; Genetic regulation; Infections; Disease
resistance; Transgenics; Beta-glucuronidase; Reporter genes

Abstract:  cis-Regulatory elements involved in tobacco mosaic
virus (TMV)-inducible expression were identified in a tobacco
PR-5 gene, encoding an acidic thaumatin-like protein. By
fusing upstream sequences of the PR-5 gene to the GUS reporter
gene and analysing transgenic plants containing these fusions
for local and systemic induction of GUS activity by TMV, it
was found that sequences between -1364 and -718 are involved
in TMV induction of PR-5 gene expression.


12                                   NAL Call. No.: 464.8 P56
The analysis of plasmid-mediated streptomycin resistance in
Erwinia amylovora. Chiou, C.S.; Jones, A.L.
St. Paul, Minn. : American Phytopathological Society; 1991
Jul. Phytopathology v. 81 (7): p. 710-714; 1991 Jul.  Includes
references.

Language:  English

Descriptors: Michigan; Malus; Erwinia amylovora; Strains;
Mutants; Drug resistance; Streptomycin; Genes; Plasmids; Dna
probes; Dna hybridization; Strain differences; Sexual
reproduction

Abstract:  Streptomycin-resistant mutants of Erwinia amylovora
were isolated from an apple orchard in Michigan and from
crabapple trees adjacent to the same orchard in 1990. Isolates
that grew on King's medium B amended with 100 microgram/ml of
streptomycin sulfate were considered to be resistant strains,
whereas isolates that failed to grow on this medium were
considered to be sensitive strains. Growth of the resistant
strains was not inhibited in a filter-paper disk assay (0.06-5
microgram of streptomycin sulfate), but growth of sensitive
strains was inhibited at concentrations as low as 0.06
microgram of streptomycin sulfate. Only sensitive strains were
detected in an additional 19 apple orchards sampled for
resistant strains. In colony blot hybridizations, an internal
portion of the streptomycin-resistance gene (probe SMP3) from
strain Psp36 of Pseudomonas syringae pv. papulans hybridized
with all streptomycin-resistant strains of E. amylovora, but
not with streptomycin-sensitive strains. Probe SMP3 hybridized
to a 2.7-kb restriction fragment from AvaI-digested total
genomic and plasmid DNA of two resistant strains of E.
amylovora and to a 1.5-kb fragment in DNA from strain Psp36 of
P. s. papulans. The probe did not hybridize with digested DNA
from sensitive strains. A 33-kb plasmid was present in all
streptomycin-resistant field strains but not in streptomycin-
sensitive strains. Streptomycin resistance was transferred by
matings to four streptomycin-sensitive recipient strains of E.
amylovora from each of two streptomycin-resistant donor
strains. Transconjugants also contained the 33-kb plasmid. DNA
from resistant strain Ea88-90 from Washington did not
hybridize with the probe, indicating that this strain contains
a resistance system unrelated to that in
streptomycin-resistant strains from Michigan.


13                                   NAL Call. No.: 464.8 P56
Application of electroporation for efficient transformation of
Xanthomonas campestris pv. oryzae.
White, T.J.; Gonzalez, C.F.
St. Paul, Minn. : American Phytopathological Society; 1991
May. Phytopathology v. 81 (5): p. 521-524; 1991 May.  Includes
references.

Language:  English

Descriptors: Oryza sativa; Xanthomonas campestris pv. oryzae;
Strains; Genetic transformation; Electroporation; Plasmids;
Dna

Abstract:  Electroporation provided an effective
transformation system for strains of Xanthomonas campestris
pv. oryzae. Transformation was observed for strain X37-2 with
plasmid pUFR027 over a range of electric field strengths
(9.2-17.1 kV/cm) and two different pulse lengths. Optimization
of the compensatory relationship between the electrical
parameters produced maximal transformation efficiency (3.6 X
10(9) transformants/microgram DNA) and frequency (1.8 X 10-2
transformant/survivor) for strain X37-2. When applied to four
other strains of X. c. oryzae, these conditions yielded lower
levels of transformation (7.8 X 10(6) to 2.7 X 10(7)
transformants/microgram DNA). Linear relationships were
observed between bacterial cell density and transformation
efficiency and between plasmid DNA concentration and frequency
of transformation.


14                                    NAL Call. No.: QH442.G4
Approaches and progress in the molecular cloning of plant
disease resistance genes.
Bennetzen, J.L.; Jones, J.D.G.
New York, N.Y. : Plenum Press; 1992.
Genetic engineering : Principles and methods v. 14: p. 99-124;
1992. Literature review.  Includes references.

Language:  English

Descriptors: Plant; Plant pathogens; Plant diseases; Genetic
resistance; Genes; Cloning; Horizontal resistance; Vertical
resistance; Genetic engineering; Literature reviews


15                                    NAL Call. No.: 500 N484
Arabidopsis as a model system for studying plant disease
resistance mechanisms.
Innes, R.; Bent, A.; Whalen, M.; Staskawicz, B.
New York, N.Y. : The Academy; 1991.
Annals of the New York Academy of Sciences v. 646: p. 228-230;
1991.  In the series analytic: Recombinant DNA technology I /
edited by A. Prokop and R.K. Bajpai.  Includes references.

Language:  English

Descriptors: Arabidopsis thaliana; Cultivars; Gene mapping;
Genetic resistance; Pseudomonas syringae pv. tomato;
Resistance mechanisms


16                                 NAL Call. No.: SB732.6.M65
At least six avirulence genes are clustered on a 90-kilobase
plasmid in Xanthomonas campestris pv. malvacearum.
De Feyter, R.; Gabriel, D.W.
St. Paul, Minn. : APS Press; 1991 Sep.
Molecular plant-microbe interactions : MPMI v. 4 (5): p.
423-432; 1991 Sep. Includes references.

Language:  English

Descriptors: Gossypium hirsutum; Xanthomonas campestris pv.
malvacearum; Strains; Virulence; Genes; Strain differences;
Host specificity; Disease resistance; Genetic resistance;
Horizontal resistance; Vertical resistance; Plasmids; Genome
analysis; Dna libraries; Gene mapping


17                                  NAL Call. No.: SB327.A1B5
Attempting genetic transformation of bean by high velocity
microporjectiles. Allavena, A.; Bernacchia, G.
Fort Collins, Colo : Howard F. Schwartz, Colorado State
University; 1991. Annual report of the Bean Improvement
Cooperative v. 34: p. 137-138; 1991. Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Agrobacterium; Dna; Genetic
transformation; Infection


18                                    NAL Call. No.: 470 C16C
Axenic culture of the downy mildew fungus Plasmopara halstedii
in Agrobacterium rhizogenes-induced roots of sunflower
(Helianthus annuus). Zahka, G.A.; Viranyi, F.
Ottawa, Ont. : National Research Council of Canada; 1991 Dec.
Canadian journal of botany; Journal canadien de botanique v.
69 (12): p. 2709-2715; 1991 Dec.  Includes references.

Language:  English

Descriptors: Helianthus annuus; Plasmopara halstedii; Plant
pathogenic fungi; In vitro culture; Roots; Agrobacterium
rhizogenes; Transgenics; Culture techniques; Pathogenicity;
Infectivity; Spore germination; Fungal morphology


19                                   NAL Call. No.: 464.8 P56
A bacteriophage-typing system for surveying the diversity and
distribution of strains of Erwinia carotovora in potato
fields.
Gross, D.C.; Powelson, M.L.; Regner, K.M.; Radamaker, G.K. St.
Paul, Minn. : American Phytopathological Society; 1991 Feb.
Phytopathology v. 81 (2): p. 220-226; 1991 Feb.  Includes
references.

Language:  English

Descriptors: Solanum tuberosum; Erwinia carotovora subsp.
carotovora; Erwinia carotovora subsp. atroseptica; Strains;
Strain differences; Detection; Identification; Bacteriophages;
Serotypes; Serological relationships; Disease surveys

Abstract:  A bacteriophage-typing system was developed and
used to survey the diversity and distribution among strains of
Erwinia carotovora subsp. carotovora and E.c. subsp.
atroseptica from the rhizospheres and stems of potatoes grown
in the Columbia Basin of the Pacific Northwest. With a phage
enrichment method and strains of E. carotovora from 25
serogroups as hosts, 13 phages displaying distinct host-range
activities were isolated from potato and soil samples. In
addition, a potato strain of E. chrysanthemi was used to
isolate phage N (Ech-3), which did not infect strains of E.
carotovora. All strains of E. c. atroseptica were sensitive to
at least one of five phages, and strains in both subspecies of
E. carotovora were sensitive to phage isolates C (304-32), E
(101-1), and J (465-2-3-6). In three commercial fields in
1981, the phage groups occurring at midseason were AEJ, E, and
EJ for E. c. atroseptica and G, GI, EF, and F for E. c.
carotovora; total rhizosphere and stem populations of E.
carotovora from symptomless plants ranged from 2 X 10(3) to 3
X 10(6) cfu g (fresh weight) at midseason. In 1982, numbers of
E. carotovora recovered from stems and rhizospheres increased
from low and sporadic levels in late May to over 10(5) cfu/g
(fresh weight) by early July. Phage group EJ of E. c.
atroseptica was predominant among the strains from Norgold
Russet and Russet Burbank seed tubers, and it composed 35-43%
of the total strains of E. carotovora recovered from
rhizosphere and stem samples later in the season. No specific
phage group was clearly associated with cultivar, date of
isolation, and either rhizosphere or stem samples. Of the 389
strains of E. carotovora collected over a 2-yr period, 44% and
48% were typed, respectively, to one of 14 phage groups and
one of nine serogroups. All strains of E. c. atroseptica were
members of serogroup I, whereas IV and XXXVII were the two
most common serogroups of E. c. carotovora. A few phage groups
and serogroups were composed of t


20                                    NAL Call. No.: 381 J824
Biochemical and molecular characterization of three barley
seed proteins with antifungal properties.
Leah, R.; Tommerup, H.; Svendsen, I.; Mundy, J.
Baltimore, Md. : American Society for Biochemistry and
Molecular Biology; 1991 Jan25.
The Journal of biological chemistry v. 266 (3): p. 1564-1573.
ill; 1991 Jan25.  Includes references.

Language:  English

Descriptors: Hordeum vulgare; Seeds; Plant proteins;
Antifungal properties; Chitinase; Beta-glucanase;
Purification; Amino acid sequences; Nucleotide sequences; Dna
probes

Abstract:  We have purified three proteins from barley
(Hordeum vulgare L.) seeds which synergistically inhibit the
growth of fungi measured in a microtiter well assay. The
proteins are a 26-kDa chitinase, a 30-kDa ribosome-
inactivating protein, and a 32-kDa (1-3)-beta-glucanase. Full-
length cDNAs encoding them were isolated and sequenced to
determine the complete primary structures of the proteins.
Northern hybridizations with the cDNAs as probes showed that
the corresponding mRNAs accumulate differentially during seed
development and germination. Chitinase mRNA accumulates to
high levels in aleurone cells during late seed development and
early germination, while high levels of mRNA encoding the
ribosome-inactivating protein accumulate only in the starchy
endosperm during late seed development. The glucanase mRNA
accumulates to low levels during seed development and to
higher levels in aleurone and seedling tissues during
germination. Southern hybridizations showed that the three
proteins are encoded by small families of three to eight
genes. Their biological roles and potential use in genetic
engineering studies are discussed.


21                                   NAL Call. No.: 448.3 AP5
Biolistic transformation of a procaryote, Bacillus megaterium.
Shark, K.B.; Smith, F.D.; Harpending, P.R.; Rasmussen, J.L.;
Sanford, J.C. Washington, D.C. : American Society for
Microbiology; 1991 Feb. Applied and environmental microbiology
v. 57 (2): p. 480-485. ill; 1991 Feb. Includes references.

Language:  English

Descriptors: Bacillus megaterium; Dna; Genetic transformation;
Laboratory methods; Plasmids

Abstract:  We present a simple and rapid method for
introducing exogenous DNA into a bacterium, Bacillus
megaterium, utilizing the recently developed biolistic
process. A suspension of B. megaterium was spread onto the
surface of nonselective medium. Plasmid pUB11O DNA, which
contains a gene that confers kanamycin resistance, was
precipitated onto tungsten particles. Using a biolistic
propulsion system, the coated particles were accelerated at
high velocities into the B. megaterium recipient cells.
Selection was done by use of an agar overlay containing 50
microgram of kanamycin per ml. Antibiotic-resistant
transformants were recovered from the medium interface after
72 h of incubation, and the recipient strain was shown to
contain the delivered plasmid by agarose gel electrophoresis
of isolated plasmid DNA. All strains of B. megaterium tested
were successfully transformed by this method, although
transformation efficiency varied among strains. Physical
variables of the biolistic process and biological variables
associated with the target cells were optimized, yielding
transformants per treated plate. This is the first report of
the biolistic transformation of a procaryote.


22                                     NAL Call. No.: Q320.A4
Biotech boosts seed proteins that halt feeding: a technology
to protect stored grains.
Cutler, K.
Cedar Falls, Iowa : Freiberg Pub; 1991 May.
AgBiotechnology news v. 8 (3): p. 12, 19; 1991 May.

Language:  English

Descriptors: Amylases; Genetic engineering; Usda; Grain
stores; Insect pests; Biological control


23                                   NAL Call. No.: TP669.I57
Biotechnology & oilseeds.
Dotson, K.
Champaign, Ill. : American Oil Chemist's Society; 1991 Jun.
International news on fats, oils and related materials v. 2
(6): p. 508-510, 512-513, 516-519, 522-523; 1991 Jun.

Language:  English

Descriptors: Oilseed plants; Biotechnology; Genetic
engineering; Fatty acids; Pest control


24                                 NAL Call. No.: QL391.N4J62
Breeding plants for resistance to nematodes.
Boerma, H.R.; Hussey, R.S.
Lake Alfred, Fla. : Society of Nematologists; 1992 Jun.
Journal of nematology v. 24 (2): p. 242-252; 1992 Jun. 
Literature review. Includes references.

Language:  English

Descriptors: Glycine max; Heterodera glycines; Pest
resistance; Plant breeding; Genetic variation; Inheritance;
Screening; Restriction fragment length polymorphism;
Literature reviews

Abstract:  Plant breeders and nematologists have developed
improved cultivars of important crop species with resistance
to plant-parasitic nematodes. The effectiveness of these
breeding efforts has depended on the availability of efficient
screening procedures, identification of adequate sources of
durable resistance, nature of the nematode feeding habit, and
knowledge of the inheritance of resistance. These factors
determine to a large degree the breeding method and potential
success of the research. Systematic searches for nematode
resistance have identified resistant germplasm lines within
crop species or from related species. When the resistance
gene(s) is from related species, incongruity barriers or
sterility of the resulting hybrids often must be overcome. In
these situations, backcrossing is usually necessary to
incorporate the resistance gene(s) and recover the desirable
commercial traits of the crop species. If the resistance
gene(s) is present within the crop species, the choice of
breeding method depends on the inheritance of the resistance,
type of screening procedure, and other important breeding
objectives for the species. In the future, plant molecular
biologists and geneticists will make available novel sources
of nematode resistance through incorporation of transgenes
from other genera. These efforts will likely require
conventional breeding strategies before commercial utilization
of an improved resistant cultivar.


25                                     NAL Call. No.: 382 P56
Carotenoids of Erwinia herbicola and an Escherichia coli HB101
strain carrying the Erwinia herbicola carotenoid gene cluster.
Hundle, B.S.; Beyer, P.; Kleinig, H.; Englert, G.; Hearst,
J.E. Oxford : Pergamon Press; 1991 Jul.
Photochemistry and photobiology v. 54 (1): p. 89-93; 1991 Jul. 
Includes references.

Language:  English

Descriptors: Erwinia herbicola; Carotenoids; Biosynthesis;
Biochemical pathways; Plasmids; Transformation; Escherichia
coli

Abstract:  Carotenoid pigments of Erwinia herbicola and a
transformed strain of Escherichia coli carrying the carotenoid
biosynthesis gene cluster of E. herbicola have been analyzed.
Both organisms are capable of making essentially the same
carotenoids, indicating that all of the genes required for the
biosynthesis of the wild type E. herbicola carotenoids have
been transformed intact into E. coli. The major products in
both species of bacteria are beta-cryptoxanthin glucoside,
zeaxanthin monoglucoside and zeaxanthin diglucoside. These
compounds are the first example of secondary, non-allylic
carotenoid glucosides. The absolute configuration 3R,3'R for
zeaxanthin diglucoside was determined from its circular
dichroism spectrum. Both species of bacteria also accumulate
small amounts of hydrocarbon carotenes with similar cis/trans
isomerization states.


26                                 NAL Call. No.: SB732.6.M65
Characterization of a DNA region required for production of
the phytotoxin coronatine by Pseudomonas syringae pv. tomato.
Ma, S.W.; Morris, V.L.; Cuppels, D.A.
St. Paul, Minn. : APS Press; 1991 Jan.
Molecular plant-microbe interactions : MPMI v. 4 (1): p.
69-74; 1991 Jan. Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Pseudomonas syringae pv.
tomato; Pathogenicity; Phytotoxins; Biosynthesis; Genetic
regulation; Genetic analysis; Dna; Insertional mutagenesis;
Mutants; Ice nucleation; Gene expression; Host parasite
relationships


27                                   NAL Call. No.: 448.3 J82
Characterization of a putative periplasmic transport system
for octopine accumulation encoded by Agrobacterium tumefaciens
Ti plasmid pTiA6. Valdivia, R.H.; Wang, L.; Winans, S.C.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Journal of bacteriology v. 173 (20): p. 6398-6405; 1991
Oct.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Octopine; Catabolism;
Plasmids; Protein transport; Nucleotide sequences; Amino acid
sequences; Enzymes; Genes

Abstract:  Neoplastic crown gall tumors incited by
Agrobacterium tumefaciens release novel amino acid or sugar
derivatives known as opines, whose synthesis is directed by
genes transferred to plant cells. Agrobacterium cells can
transport and catabolize these compounds as sources of carbon
and nitrogen. This article describes a region of the pTiA6
plasmid which is required for catabolism of the opine octopine
and whose transcription is induced by octopine. This region of
the plasmid contains four open reading frames, occQ, occM,
occP, and occJ, which show homology to the family of so-called
shock-sensitive permeases. TnphoA mutagenesis demonstrated
that the OccJ and OccM proteins lie fully or partly in the
periplasmic space. The OccJ protein was identified by
electrophoresis and found to be fully localized in the
periplasmic space. When these proteins were expressed in
Escherichia coli, radiolabeled octopine became cell-
associated.


28                                   NAL Call. No.: 448.3 AP5
Characterization of an unusual new Agrobacterium tumefaciens
strain from Chrysanthemum morifolium ram.
Bush, A.L.; Pueppke, S.G.
Washington, D.C. : American Society for Microbiology; 1991
Sep. Applied and environmental microbiology v. 57 (9): p.
2468-2472; 1991 Sep. Includes references.

Language:  English

Descriptors: Dendranthema morifolium; Agrobacterium
tumefaciens; Strains; Characterization; Pathogenicity; Glycine
max; Host range; Catabolism

Abstract:  We characterized five isolates of Agrobacterium
tumefaciens from naturally occurring galls on Chrysanthemum
morifolium. The isolates are similar, possibly identical,
members of a single strain of A. tumefaciens that we designate
Chry5. The strain is a biotype I, as indicated by its response
to both newly described and traditional biotype tests. Chry5
produces tumors on at least 10 plant species. It is unusual in
its ability to form efficiently large tumors on soybean
(Glycine max), a species normally refractory to
transformation. Chry5 is unable to utilize octopine or
mannopine as a carbon source. Although Chry5 can catabolize a
single isomer each of nopaline and succinamopine, it differs
from other known nopaline and succinamopine strains in its
insensitivity to agrocin 84. This pattern of opine catabolism
is unique among Agrobacterium strains examined to date. All
five isolates of Chry5 contain at least two plasmids, one of
which shares homology with pTiB6.


29                                   NAL Call. No.: 448.3 AP5
Characterization of fluorescent siderophore-mediated iron
uptake in Pseudomonas sp. strain M114: evidence for the
existence of an additional ferric siderophore receptor.
Morris, J.; O'Sullivan, D.J.; Koster, M.; Leong, J.; Weisbeek,
P.J.; O'Gara, F.
Washington, D.C. : American Society for Microbiology; 1992
Feb01. Applied and environmental microbiology v. 58 (2): p.
630-635; 1992 Feb01. Includes references.

Language:  English

Descriptors: Plant disease control; Pseudomonas; Strains;
Siderophores; Receptors; Uptake; Iron; Proteins; Mutants;
Biological control agents

Abstract:  In Pseudomonas sp. strain M114, the outer membrane
receptor for ferric pseudobactin M114 was shown to transport
ferric pseudobactins B10 and A225, in addition to its own. The
gene encoding this receptor, which was previously cloned on
pCUP3, was localized by Tn5 mutagenesis to a region comprising
> 1.6 kb of M114 DNA. A mutant (strain M114R1) lacking this
receptor was then created by a marker exchange technique.
Characterization of this mutant by using purified pseudobactin
M114 in radiolabeled ferric iron uptake studies confirmed that
it was completely unable to utilize this siderophore for
acquisition of iron. In addition, it lacked an outer membrane
protein band of 89 kDa when subjected to sodium dodecyl
sulfate-polyacrylamide gel electrophoresis. As a result,
growth of the mutant was severely restricted under low-iron
conditions. However, this phenotype was reversed in the
presence of another fluorescent siderophore (pseudobactin
MT3A) from Pseudomonas sp. strain MT3A, suggesting the
presence of a second receptor in strain M114. Furthermore,
wild-type Pseudomonas sp. strain B24 was not able to utilize
ferric pseudobactin MT3A, and this phenotype was not reversed
upon expression of the M114 receptor encoded on pCUP3.
However, a cosmid clone (pMS1047) that enabled strain B24 to
utilize ferric pseudobactin MT3A was isolated from an M114
gene bank. Radiolabel transport assays with purified
pseudobactin MT3A confirmed this event. Plasmid pMS1047 was
shown to encode an outer membrane protein of 81 kDa in strain
B24 under iron-limiting conditions; this protein corresponds
to a similar protein in strain M114.


30                                   NAL Call. No.: 442.8 Z34
Characterization of the supervirulent virG gene of the
Agrobacterium tumefaciens plasmid pTiBo542.
Chen, C.Y.; Wang, L.; Winans, S.C.
Berlin, W. Ger. : Springer International; 1991 Nov.
M G G : Molecular and general genetics v. 230 (1/2): p.
302-309; 1991 Nov. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Genes; Virulence;
Nucleotide sequences; Plasmids; Promoters; Bacterial proteins;
Gene expression

Abstract:  The virG gene of the Agrobacterium tumefaciens Ti
plasmid pTiBo542 has previously been reported to elicit
stronger vir gene expression than its counterpart in the pTiA6
plasmid, a property we call the "superactivator" phenotype.
The DNA sequence of the pTiBo542 virG gene was determined and
compared to that of the pTiA6 gene. The DNA sequences of these
genes differ at 16 positions: two differences are in the
promoter regions, 12 are in the coding regions, and two are in
the 3' untranslated regions. The 3' end of the pTiA6 virG gene
also contains a probable insertion sequence that is not found
downstream of the pTiBo542 gene. The base pair differences in
the two coding regions result in only two amino acid
differences, both in the aminoterminal halves of the proteins.
Five hybrid virG genes were constructed and used to activate
the expression of a virB::lacZ gene fusion. Differences in the
coding regions of these genes accounted for most of the
superactivator phenotype, while differences at the promoter
and 3' untranslated regions also contributed. These findings
suggest that the properties of these VirG proteins and their
quantities are important for vir gene induction, and also
suggest a long-term selective pressure for mutations
contributing to differences between these two genes.


31                                   NAL Call. No.: 448.3 J82
Characterization of three Agrobacterium tumefaciens avirulent
mutants with chromosomal mutations that affect induction of
vir genes. Metts, J.; West, J.; Doares, S.H.; Matthysse, A.G.
Washington, D.C. : American Society for Microbiology; 1991
Feb. Journal of bacteriology v. 173 (3): p. 1080-1087. ill;
1991 Feb.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Mutants; Genes;
Virulence; Chromosomes; Lipopolysaccharides

Abstract:  Three Agrobacterium tumefaciens mutants with
chromosomal mutations that affect bacterial virulence were
isolated by transposon mutagenesis. Two of the mutants were
avirulent on all hosts tested. The third mutant, Ivr-211, was
a host range mutant which was avirulent on Bryophyllum
diagremontiana, Nicotiana tabacum, N. debneyi, N. glauca, and
Daucus carota but was virulent on Zinnia elegans and
Lycopersicon esculentum (tomato). That the mutant phenotype
was due to the transposon insertion was determined by cloning
the DNA containing the transposon insertion and using the
cloned DNA to replace the wild-type DNA in the parent
bacterial strain by marker exchange. The transposon insertions
in the three mutants mapped at three widely separated
locations on the bacterial chromosome. The effects of the
mutations on various steps in tumor formation were examined.
All three mutants showed no alteration in binding to carrot
cells. However, none of the mutants showed any induction of
vir genes by acetosyringone under conditions in which the
parent strain showed vir gene induction. When the mutant
bacteria were examined for changes in surface components, it
was found that all three of the mutants showed a similar
alteration in lipopolysaccharide (LPS). LPS from the mutants
was larger in size and more heavily saccharide substituted
than LPS from the parent strain. Two of the mutants showed no
detectable alteration in outer membrane and periplasmic space
proteins. The third mutant, Ivr-225, was missing a 79-kDa
surface peptide. The reason(s) for the failure of vir gene
induction in these mutants and its relationship, if any, to
the observed alteration in LPS are unknown.


32                                   NAL Call. No.: 442.8 Z34
Characterization of two beta-tubulin genes from Geotrichum
candidum. Gold, S.E.; Casale, W.L.; Keen, N.T.
Berlin, W. Ger. : Springer International; 1991 Nov.
M G G : Molecular and general genetics v. 230 (1/2): p.
104-112; 1991 Nov. Includes references.

Language:  English

Descriptors: Geotrichum candidum; Endomycetales; Trichoderma
hamatum; Genes; Introns; Tubulin; Promoters; Nucleotide
sequences; Amino acid sequences; Genetic transformation; Gene
expression; Restriction mapping

Abstract:  The beta-tubulin genes G beta 1 and G beta 1 G beta
2 from phytopathogenic hemiascomycete Geotrichum candidum were
found to be highly diverged in amino acid sequence from those
of other filamentous fungi. G beta 1 and G beta 2 were also
divergent from each other, with the coding regions sharing
only 66% nucleotide sequence homology and 64% amino acid
identity. However, the proteins shared 82% similarity and only
25 of the 161 non-identical amino acid substitutions were non-
conservative. The organization of G beta 1 is similar to other
fungal beta-tubulin genes, but G beta 2 has several unusual
features; it has 2 amino acid additions in the N-terminal 40
residues and must employ an uncommon 5' splice junction
sequence in preference to an overlapping perfect consensus.
The amino acid change found to confer benomyl resistance in
Neurospora crassa was also present in G beta 2. G beta 1 has
four introns which are located similarly to those of beta-
tubulin genes in other fungi. G beta 2, however, has a single
intron in a unique location. Translational fusions employing
the 5' non-coding regions of the two Geotrichum beta-tubulin
genes were made with the hygromycin phosphotransferase gene
and shown to function in Schizosaccharomyces pombe and
Trichoderma hamatum. However, G. candidum could not be
transformed with these or other tested plasmids commonly used
for fungal transformation.


33                                   NAL Call. No.: 448.3 AP5
Chemotaxis of Pseudomonas syringae subsp. savastanoi virulence
mutants. Soby, S.; Kirkpatrick, B.; Kosuge, T.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Applied and environmental microbiology v. 57 (10): p.
2918-2920; 1991 Oct. Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. savastanoi; Mutants;
Genes; Virulence; Chemotaxis; Iaa; Deficiency; Adenosine;
Motility

Abstract:  Several mutants of Pseudomonas syringae subsp.
savastanoi were tested for their ability to sense a to a
chemotactic gradient in low concentrations of yeast extract.
The mutants were deficient in one or both of the genes coding
for the synthesis of the plant hormones indole-3-acetic acid
(IAA) and isopentenyl adenosine. Mutations which resulted in
the loss of IAA production were due to the loss of the entire
plasmid containing the iaa operon or to an 18-kb deletion of
the IAA region. Additional mutants tested were deficient in
their ability to produce isopentenyl adenosine as a result of
the loss of the ptz-bearing plasmid. In all cases, strains
which had lost the ability to produce IAA exhibited enhanced
motility of up to 2.5 times that of the wild type (IAA+) in
medium containing 0.01% yeast extract. No differences in
motility were observed on medium containing lower
concentrations of yeast extract. The presence or absence of
the cytokinin plasmid and the presence or absence of inorganic
nitrogen in the medium had no effect on the relative mobility
of the strains.


34                                   NAL Call. No.: 448.3 J82
The cloned avirulence gene avrPto induces disease resistance
in tomato cultivars containing the Pto resistance gene.
Ronald, P.C.; Salmeron, J.M.; Carland, F.M.; Staskawicz, B.J.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Journal of bacteriology v 174 (5): p. 1604-1611; 1992
Mar.  Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Pseudomonas syringae pv.
tomato; Genes; Disease resistance; Glycine max; Cultivars;
Virulence

Abstract:  Resistance of tomato plants to the bacterial
pathogen Pseudomonas syringae pv. tomato race 0 is controlled
by the locus Pto. A bacterial avirulence gene was cloned by
constructing a cosmid library from an avirulent P. syringae
pv. tomato race, conjugating the recombinants into a strain of
P. syringae pv. maculicola virulent on a tomato cultivar
containing Pto, and screening for those clones that converted
the normally virulent phenotype to avirulence. The cloned
gene, designated avrPto, reduced multiplication of P. syringae
pv. tomato transconjugants specifically on Pto tomato lines,
as demonstrated by bacterial growth curve analyses. Analysis
of F2 populations revealed cosegregation of resistance to P.
syringae pv. tomato transconjugants carrying avrPto with
resistance to P. syringae pv. tomato race 0. Surprisingly,
mutation of avrPto in P. syringae pv. tomato race 0 does not
eliminate the avirulent phenotype of race 0, suggesting that
additional, as yet uncharacterized, avirulence genes and/or
resistance genes may contribute to specificity in the avrPto-
Pto interaction. Genetic analysis indicates that this
resistance gene(s) would be tightly linked to Pto.
Interestingly, P. syringae pv. glycinea transconjugants
carrying avrPto elicit a typical hypersensitive resistant
response in the soybean cultivar Centennial, suggesting
conservation of Pto function between two crop plants, tomato
and soybean.


35                                   NAL Call. No.: 442.8 Z34
Cloning and analysis of CUT1, a cutinase gene from Magnaporthe
grisea. Sweigard, J.A.; Chumley, F.G.; Valent, B.
Berlin, W. Ger. : Springer International; 1992 Mar.
M G G : Molecular and general genetics v. 232 (2): p. 174-182;
1992 Mar. Includes references.

Language:  English

Descriptors: Magnaporthe grisea; Genes; Esterases; Nucleotide
sequences; Amino acid sequences; Introns; Enzyme activity;
Genetic transformation; Cutin; Hydrolysis; Genetic code;
Restriction mapping; Gene expression; Messenger RNA; Gene
dosage

Abstract:  A gene from Magnaporthe grisea was cloned using a
cDNA clone of the Colletotrichum gloeosporioides cutinase gene
as a heterologous probe; the nucleotide sequence of a 2 kb DNA
segment containing the gene has been determined. DNA
hybridization analysis shows that the M. grisea genome
contains only one copy of this gene. The predicted polypeptide
contains 228 amino acids and is homologous to the three
previously characterized cutinases, showing 74% amino acid
similarity to the cutinase of C. gloeosporioides. Comparison
with previously determined cutinase sequences suggests that
the gene contains two introns, 115 and 147 bp in length. The
gene is expressed when cutin is the sole carbon source but not
when the carbon source is cutin and glucose together or
glucose alone. Levels of intracellular and extracellular
cutinase activity increase in response to growth in the
presence of cutin. The activity level is higher in a
transformant containing multiple copies of the cloned gene
than in the parent strain. Non-denaturing polyacrylamide gels
stained for esterase activity show a single major band among
intracellular and extracellular proteins from cutin-grown
cultures that is not present among intracellular and
extracellular proteins prepared from glucose-grown or carbon-
starved cultures. This band stains more intensely in extracts
from the multicopy transformant than in extracts from the
parent strain. We conclude that the cloned DNA contains a M.
grisea gene for cutinase, which we have named CUT1.


36                                   NAL Call. No.: 448.3 J82
Cloning and characterization of a gene required for the
secretion of extracellular enzymes across the outer membrane
by Xanthomonas campestris pv. campestris.
Hu, N.T.; Hung, M.N.; Chiou, S.J.; Tang, F.; Chiang, D.C.;
Huang, H.Y.; Wu, C.Y.
Washington, D.C. : American Society for Microbiology; 1992
Apr. Journal of bacteriology v. 174 (8): p. 2679-2687; 1992
Apr.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. campestris; Membranes;
Secretion; Enzymes; Genes; Nucleotide sequences; Amino acid
sequences; Cloning

Abstract:  Nonpathogenic mutants of Xanthomonas campestris pv.
campestris, generated from transposon mutagenesis, accumulated
extracellular polygalacturonate lyase, alpha-amylase, and
endoglucanase in the periplasm. The transposon Tn5 was
introduced by a mobilizable, suicidal plasmid, pSUP2021 or
pEYDG1. Genomic banks of wild-type X. campestris pv.
campestris, constructed on the broad-host-range, mobilizable
cosmid pLAFRI or pLAFR3, were conjugated with one of the
mutants, designated XC1708. Recombinant plasmids isolated by
their ability to complement XC1708 can be classified into two
categories. One, represented by pLASC3, can complement some
mutants, whereas the other, represented by a single plasmid,
pLAHH2, can complement all of the other mutants. Restriction
mapping showed that the two recombinant plasmids shared an
EcoRI fragment of 8.9 kb. Results from subcloning, deletion
mapping, and mini-Mu insertional mutation of the 8.9-kb EcoRI
fragment suggested that a 4.2-kb fragment was sufficient to
complement the mutant XC1708. Sequence analysis of this 4.2-kb
fragment revealed three consecutive open reading frames
(ORFs), ORF1, ORF2, and ORF3. Hybridization experiments showed
that Tn5 in the genome of XC1708 and other mutants
complemented by pLASC3 was located in ORF3, which could code
for a protein of 83.5 kDa. A signal peptidase 11 processing
site was identified at the N terminus of the predicted amino
acid sequence. Sequence homology of 51% was observed between
the amino acid sequences predicted from ORF3 and the pulD gene
of Klebsiella species.


37                                   NAL Call. No.: 448.3 J82
Cloning and characterization of pathogenicity genes from
Xanthomonas campestris pv. glycines.
Hwang, I.; Lim, S.M.; Shaw, P.D.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Journal of bacteriology v. 174 (6): p. 1923-1931; 1992
Mar.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. glycines; Genes;
Mutants; Pathogenicity; Nucleotide sequences; Amino acid
sequences

Abstract:  Nonpathogenic mutants of Xanthomonas campestris pv.
glycines 8ra were generated with N-methyl-N-nitro-N'-
nitrosoguanidine to identify and characterize pathogenicity
genes of the bacterium. A total of 16 nonpathogenic mutants
were isolated from 2,000 colonies. One mutant, NP1, was chosen
for further study. NP1 did not multiply in soybean cotyledons.
A genomic library of strain 8ra was constructed in the cosmid
pLAFR3, and the cosmids were tested for complementation in
NP1. One cosmid clone, pIH1, which contained a 31-kb insert,
complemented mutant NP1. A restriction map of PIH1 was
constructed, and deletion analyses identified a 10-kb HindIII
fragment that restored pathogenicity to NP1. Southern
hybridization analysis indicated that DNA sequences in the 10-
kb HindIII fragment are conserved among other X. campestris
pathovars tested. Three regions responsible for restoring
pathogenicity have been identified by Tn3-HoHo1 mutagenesis. A
2.7-kb ClaI fragment was sequenced, and two possible open
reading frames (ORF1 and ORF2) were found. Results indicated
that ORF2 but not ORF1 may be expressed in Escherichia coli
and in X. campestris pv. glycines. The carboxy terminus of the
potential polypeptide encoded by ORF2 has an amino acid
sequence similar to that of the gamma subunit of oxaloacetate
decarboxylase, which is involved in sodium ion transport in
Klebsiella pneumoniae.


38                                   NAL Call. No.: 448.3 AP5
Cloning and detection of chromosomal and extrachromosomal DNA
from mycoplasmalike organisms that cause yellow dwarf disease
of rice. Nakashima, K.; Kato, S.; Iwanami, S.; Murata, N.
Washington, D.C. : American Society for Microbiology; 1991
Dec. Applied and environmental microbiology v. 57 (12): p.
3570-3575; 1991 Dec. Includes references.

Language:  English

Descriptors: Oryza sativa; Mycoplasma-like organisms;
Chromosomes; Dna; Dna probes; Disease vectors; Nephotettix
cincticeps

Abstract:  DNA was extracted from rice plants infected with
mycoplasmalike organisms (MLOs) causing yellow disease. DNA of
the causal agent was separated from the host DNA by repeated
bisbenzimide-CsCl equilibrium density gradient
centrifugations. MLO DNA cut by HindIII was ligated into
plasmid Bluescript II and cloned in Escherichia coli NM522.
The DNA inserts were labeled with peroxidase and employed as
probes in hybridization. Southern analysis revealed that the
insert in pRYD-12 consisted of one, presumably chromosomal,
piece of MLO DNA, whereas the insert in pRYD-19, another
recombinant plasmid, consisted of one, presumably
extrachromosomal, piece of MLO DNA. Cloned DNA probes were
successfully applied in dot blot hybridization for the
detection of rice yellow dwarf disease MLOs in rice plants and
in an insect vector, the green rice leafhopper (Nephotettix
cincticeps).


39                                    NAL Call. No.: QH426.C8
Cloning and expression of a chitinase gene from the
hyperparasitic fungus Aphanocladium album.
Blaiseau, P.L.; Kunz, C.; Grison, R.; Bertheau, Y.; Brygoo, Y.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (1): p. 61-66; 1992.  Includes
references.

Language:  English

Descriptors: Deuteromycotina; Fungal antagonists; Fusarium
oxysporum; Hyperparasitism; Genes; Chitinase; Recombinant 
DNA; Gene expression; Messenger  RNA; Genetic transformation;
Nucleotide sequences; Restriction mapping; Genetic regulation;
Amino acid sequences

Abstract:  Recombinant clones from a cDNA library of an
Aphanocladium album chitinase-overproducing mutant strain were
isolated by screening with antiserum against a 39 kDa
chitinase purified from this hyperparasitic fungus. Analysis
of the isolated positive clones indicated that most of them
carried the same cDNA. A cDNA from this group was used as a
hybridization probe to isolate an 8 kb DNA fragment from a
genomic library of the wild-type strain. The chitinase 1 gene
was mapped to this fragment by two independent approaches. Its
partial DNA sequence was in perfect agreement with an amino-
terminal peptide sequence obtained by sequencing 23 amino
acids of the 39 kDa chitinase. Its transfer in Fusarium
oxysporum resulted in a transformant producing both a protein
of about 39 kDa that cross-reacted with the chitinase
antiserum and a chitinase activity that was inhibited by the
same antiserum. Northern blot analysis indicates that the
cloned chitinase gene was subject to catabolite repression and
appeared inducible by chitin.


40                                   NAL Call. No.: 448.3 J82
Cloning and expression of the tabtoxin biosynthetic region
from Pseudomonas syringae.
Kinscherf, T.G.; Coleman, R.H.; Barta, T.M.; Willis, D.K.
Washington, D.C. : American Society for Microbiology; 1991
Jul. Journal of bacteriology v. 173 (13): p. 4124-4132. ill;
1991 Jul.  Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Nicotiana tabacum;
Pseudomonas syringae; Cloning; Bacterial toxins; Genes;
Insertional mutagenesis; Mutants; Genetic transformation;
Complementation; Cosmids; Pathogenicity; Deletions; Gene
expression; Plant diseases; Disease resistance

Abstract:  Pseudomonas syringae BR2, a causal agent of bean
wildfire, was subjected to Tn5 mutagenesis in an effort to
isolate mutants unable to produce the beta-lactam antibiotic
tabtoxin. Three of the tabtoxin-minus (Tox-) mutants generated
appeared to have physically linked Tn5 insertions and retained
their resistance to the active toxin form, tabtoxinine-beta-
lactam (TbetaL). The wild-type DNA corresponding to the
mutated region was cloned and found to restore the Tn5 mutants
to toxin production. The use of cloned DNA from the region as
hybridization probes revealed that the region is highly
conserved among tabtoxin-producing pathovars of P. syringae
and that the region deletes at a relatively high frequency
(10(-3)/CFU) in BR2. The Tox-deletion mutants also lost
resistance to tabtoxinine-beta-lactam. A cosmid designated
pRTBL823 restored toxin production and resistance to BR2
deletion mutants. This cosmid also converted the tabtoxin-
naive P. syringae epiphyte Cit7 to toxin production and
resistance, indicating that pRTBL823 contains a complete set
of biosynthetic and resistance genes. Tox- derivatives of BR2
did not produce disease symptoms on bean. Clones that restored
toxin production to both insertion and deletion mutants also
restored the ability to cause disease. However, tabtoxin-
producing Cit7 derivatives remained nonpathogenic on bean and
tobacco, suggesting that tabtoxin production alone is not
sufficient to cause disease.


41                                   NAL Call. No.: 448.3 J82
Cloning and sequencing of an Agrobacterium tumefaciens beta-
glucosidase gene involved in modifying a vir-inducing plant
signal molecule. Castle, L.A.; Smith, K.D.; Morris, R.O.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Journal of bacteriology v 174 (5): p. 1478-1486; 1992
Mar.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Beta-glucosidase;
Genes; Cloning; Nucleotide sequences; Amino acid sequences;
Phenolic compounds; Enzyme activity; Cellobiose

Abstract:  Induction of Agrobacterium tumefaciens virulence
genes by plant phenolic compounds is essential for successful
T-DNA transfer to a host plant. In Douglas fir needles, the
major virulence region inducer is the glycoside coniferin
(J.W. Morris and R.O. Morris, Proc. Natl. Acad. Sci. USA
87:3612-3618, 1990). Agrobacterium strains with high beta-
glucosidase activity respond to coniferin and infect Douglas
fir seedlings, whereas most strains with low beta-glucosidase
activity fail to respond to coniferin and are avirulent on
this host. We have cloned two beta-glucosidase genes from A.
tumefaciens B3/73 and sequenced one of them, cbg1. It appears
to be part of a polycistronic unit and shows a high bias for
GC-rich codons. When expressed in Escherichia coli, Cbg1 beta-
glucosidase hydrolyzes coniferin but not cellobiose. The 88-
kDa predicted product of cbg1 is highly similar to one other
bacterial beta-glucosidase and several fungal beta-
glucosidases. There is little homology between Cbg1 and other
bacterial beta-glucosidases, including an Agrobacterium
cellobiase.


42                                 NAL Call. No.: SB732.6.M65
Cloning of a melanin biosynthetic gene essential for
appressorial penetration of Colletotrichum lagenarium.
Kubo, Y.; Nakamura, H.; Kobayashi, K.; Okuno, T.; Furusawa, I.
St. Paul, Minn. : APS Press; 1991 Sep.
Molecular plant-microbe interactions : MPMI v. 4 (5): p.
440-445; 1991 Sep. Includes references.

Language:  English

Descriptors: Cucumis sativus; Colletotrichum orbiculare;
Colonizing ability; Appressoria; Infection; Cell walls;
Penetration; Pathogenicity; Melanins; Biosynthesis; Genes;
Mutants; Strains; Albinos; Cloning; Genetic analysis; Genetic
transformation


43                                    NAL Call. No.: QH426.C8
Cloning the REC1 gene of Ustilago maydis.
Holden, D.W.; Spanos, A.; Kanuga, N.; Banks, G.R.
Berlin, W. Ger. : Springer International; 1991.
Current genetics v. 20 (1/2): p. 145-150; 1991.  Includes
references.

Language:  English

Descriptors: Ustilago zeae; Genes; Cloning; Homologous
recombination; Dna repair; Ultraviolet radiation;
Susceptibility; Induced mutations; Insertional mutagenesis;
Complementation; Alleles

Abstract:  The REC1 gene of Ustilago maydis plays a key role
in homologous recombination and the repair of damaged DNA. In
order to understand the nature and functions of the gene
product, the gene has been cloned by functional
complementation. A 3.8 kb cloned fragment complements the
pleiotropic mitotic phenotype of different rec1 alleles. It
does not complement the UV sensitivity of two other sensitive
mutants. Disruption of the chromosomal copy of the 1.566 kb
open reading frame within this fragment reproduces the rec1
pleiotropic phenotype. Furthermore, in diploids this disrupted
reading frame is unable to complement previously characterised
rec1 alleles.


44                                    NAL Call. No.: 500 N21P
Components of the protein-excretion apparatus of Pseudomonas
aeruginosa are processed by the type IV prepilin peptidase.
Nunn, D.N.; Lory, S.
Washington, D.C. : The Academy; 1992 Jan01.
Proceedings of the National Academy of Sciences of the United
States of America v. 89 (1): p. 47-51; 1992 Jan01.  Includes
references.

Language:  English

Descriptors: Pseudomonas aeruginosa; Mutants; Nucleotide
sequences; Peptides; Proteins; Amino acid sequences; Excretion

Abstract:  In the Gram-negative pathogen Pseudomonas
aeruginosa, mutants in the gene for the prepilin peptidase
(pilD) are pleiotropic, as they not only fail to process pilin
but also accumulate in the periplasm, in their mature form,
several toxins and hydrolytic enzymes that are normally
exported to the external medium (excreted). We have suggested
that this excretion defect is due to the lack of PilD-
dependent processing of proteins that share sequences in
common with the prepilin subunit and that are components of a
protein-excretion machinery. In this paper we report the
isolation and characterization of transposon-induced excretion
mutants with phenotypes similar to that of a pilD gene mutant.
Using oligonucleotide probes designed to recognize sequences
encoding the cleavage site of the type IV prepilins, we have
isolated four linked genes with the predicted putative PilD-
dependent cleavage site. Site-specific mutations within these
genes have shown that they are required for protein excretion,
and PilD-dependent processing of at least one of the four
encoded proteins was demonstrated. Evidence suggests that
similar components play a role in protein excretion in a wide
variety of Gram-negative bacteria.


45                                    NAL Call. No.: 470 SCI2
Conjugative transfer by the virulence system of Agrobacterium
tumefaciens. Beijersbergen, A.; Dulk-Ras, A. den;
Schilperoort, R.A.; Hooykaas, P.J.J. Washington, D.C. :
American Association for the Advancement of Science; 1992
May29.
Science v. 256 (5061): p. 1324-1327; 1992 May29.  Includes
references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Dna; Gene transfer;
Plasmids; Tumors

Abstract:  Agrobacterium tumefaciens transfers part of its Ti
plasmid, the transferred DNA (T-DNA), to plant cells during
tumor induction. Expression of this T-DNA in plant cells
results in their transformation into tumor cells. There are
similarities between the process of T-DNA transfer to plants
and the process of bacterial conjugation. Here, the T-DNA
transfer machinery mediated conjugation between bacteria.
Thus, products of the Vir region of the Ti plasmid of
Agrobacterium tumefaciens, normally involved in transfer of
DNA from bacteria to plants, can direct the conjugative
transfer of an IncQ plasmid between agrobacteria.


46                                   NAL Call. No.: 448.3 AP5
Conservation of plasmid DNA sequences in coronatine-producing
pathovars of Pseudomonas syringae.
Bender, C.L.; Young, S.A.; Mitchell, R.E.
Washington, D.C. : American Society for Microbiology; 1991
Apr. Applied and environmental microbiology v. 57 (4): p.
993-999; 1991 Apr. Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. tomato; Pseudomonas
syringae pv. atropurpurea; Pseudomonas syringae pv. glycinea;
Pseudomonas syringae pv. morsprunorum; Plasmids; Dna
hybridization; Genes; Bacterial toxins; Biosynthesis; Induced
mutations; Restriction mapping; Phytotoxicity; Bioassays;
Crops

Abstract:  In Pseudomonas syringae pv. tomato PT23.2, plasmid
pPT23A (101 kb) is involved in synthesis of the phytotoxin
coronatine (C. L. Bender, D. K. Malvick, and R. E. Mitchell,
J. Bacteriol. 171:807-812, 1989). The physical
characterization of mutations that abolished coronatine
production indicated that at least 30 kb of pPT23A DNA are
required for toxin synthesis. In the present study, 32P-
labeled DNA fragments from the 30-kb region of pPT23A
hybridized to plasmid DNAs from several coronatine-producing
pathovars of P. syringae under conditions of high stringency.
These experiments indicated that this region of pPT23A was
strongly conserved in large plasmids (90 to 105 kb) that
reside in P. syringae pv. atropurpurea, glycinea, and
morsprunorum. The functional significance of the observed
homology was demonstrated in marker-exchange experiments in
which Tn5-inactivated sequences from the 30-kb region of
pPT23A were used to mutate coronatine synthesis genes in the
three heterologous pathovars. Physical characterization of the
Tn5 insertions generated by marker exchange indicated that
genes controlling coronatine synthesis in P. syringae pv.
atropurpurea 1304, glycinea 4180, and morsprunorum 567 and
3714 were located on the large indigenous plasmids where
homology was originally detected. Therefore, coronatine
biosynthesis genes are strongly conserved in the plasmid DNAs
of four producing pathovars, despite their disparate origins
(California, Japan, New Zealand, Great Britain, and Italy).


47                                   NAL Call. No.: 448.3 J82
Conservation of the gene for outer membrane protein OprF in
the family Pseudomonadaceae: sequence of the Pseudomonas
syringae oprF gene. Ullstrom, C.A.; Siehnel, R.; Woodruff, W.;
Steinbach, S.; Hancock, R.E.W. Washington, D.C. : American
Society for Microbiology; 1991 Jan. Journal of bacteriology v.
173 (2): p. 768-775; 1991 Jan.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae; Genes; Membranes; Proteins;
Nucleotide sequences; Amino acid sequences

Abstract:  The conservation of the oprF gene for the major
outer membrane protein OprF was determined by restriction
mapping and Southern blot hybridization with the Pseudomonas
aeruginosa oprF gene as a probe. The restriction map was
highly conserved among 16 of the 17 serotype type strains and
42 clinical isolates of P. aeruginosa. Only the serotype 12
isolate and one clinical isolate showed small differences in
restriction pattern. Southern probing of PstI chromosomal
digests of 14 species from the family Pseudomonadaceae
revealed that only the nine members of rRNA homology group I
hybridized with the oprF gene. To reveal the actual extent of
homology, the oprF gene and its product were characterized in
Pseudomonas syringae. Nine strains of P. syringae from seven
different pathovars hybridized with the P. aeruginosa gene to
produce five different but related restriction maps. All
produced an OprF protein in their outer membranes with the
same apparent molecular weight as that of P. aeruginosa OprF.
In each case the protein reacted with monoclonal antibody
MA4-10 and was similarly heat and 2-mercaptoethanol
modifiable. The purified OprF protein of the type strain P.
syringae pv. syringae ATCC 19310 reconstituted small channels
in lipid bilayer membranes. The oprF gene from this latter
strain was cloned and sequenced. Despite the low level of DNA
hybridization between P. aeruginosa and P. syringae DNA, the
OprF gene was highly conserved between the species with 72%
DNA sequence identity and 68% amino acid sequence identity
overall. The carboxy terminus-encoding region of P. syringae
oprF showed 85 and 33% identity, respectively, with the same
regions of the P. aeruginosa oprF and Escherichia coli ompA
genes.


48                                   NAL Call. No.: 448.3 J82
Constitutive mutations of Agrobacterium tumefaciens
transcriptional activator virG.
Pazour, G.J.; Ta, C.N.; Das, A.
Washington, D.C. : American Society for Microbiology; 1992
Jun. Journal of bacteriology v. 174 (12): p. 4169-4174; 1992
Jun.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Mutations; Genes;
Virulence; Gene expression

Abstract:  The virulence (vir) genes of Agrobacterium
tumefaciens Ti plasmids are positively regulated by virG in
conjunction with virA and plant-derived inducing molecules. A
procedure that utilizes both genetic selection and a genetic
screen was developed to isolate mutations in virG that led to
elevated levels of vir gene expression in the absence of virA
and plant phenolic inducers. Mutants were isolated at a
frequency of 1 in 10(7) to 10(8). Substitution mutations at
two positions in the virG coding region were found to result
in the desired phenotype. One mutant had an asparagine-to-
aspartic acid substitution at residue 54, and the other
contained an isoleucine-to-leucine substitution at residue
106. In both cases, the mutant phenotype required the presence
of the active-site aspartic acid residue at position 52.
Further analysis showed that no other substitution at residue
54 resulted in a constitutive phenotype. In contrast, several
substitutions at residue 106 led to a constitutive phenotype.
The possible roles of the residues at positions 54 and 106 in
VirG function are discussed.


49                                   NAL Call. No.: 448.3 J82
Controlled expression of the transcriptional activator gene
virG in Agrobacterium tumefaciens by using the Escherichia
coli lac promoter. Chen, C.Y.; Winans, S.C.
Washington, D.C. : American Society for Microbiology; 1991
Feb. Journal of bacteriology v. 173 (3): p. 1139-1144; 1991
Feb.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Genes; Gene
expression; Induction; Ph

Abstract:  The Agrobacterium VirG protein is normally
expressed from two promoters in response to multiple stimuli,
including plant-released phenolics (at promoter P1) and acidic
growth media (at promoter P2). To simplify the analysis of vir
gene induction, we sought to create Agrobacterium strains in
which virG could be expressed in a controllable fashion. To
study the possibility of using the lac promoter and repressor,
we constructed a plasmid containing the lac promoter fused to
the lacZ structural gene. A derivative of this plasmid
containing the lacIq gene was also constructed. The plasmid
not containing lacIq expressed high levels of beta-
galactosidase. The plasmid containing lacIq expressed beta-
galactosidase at very low levels in the absence of o-
nitrophenyl-beta-D-galactosidase (IPTG) and at moderate levels
in the presence of IPTG. We also fused the lac promoter to a
virG::lacZ translational fusion and found that IPTG elevated
expression of this translational fusion to moderate levels,
though not to levels as high as from the stronger of the two
native virG promoters. Finally, the lac promoter was used to
express the native virG gene in strains containing a
virB::lacZ translational fusion. virB expression in this
strain depended on addition of IPTG as well as the vir gene
inducer acetosyringone. In a similar strain lacking lacIq,
virB expression was greater than in a strain in which virG was
expressed from its native promoters. Expression of virG from
the lac promoter did not alter the acidic pH optimum for vir
gene induction, indicating that the previously observed
requirement for acidic media was not due solely to the need to
induce P2.


50                                    NAL Call. No.: 1.9 P69P
Copper
 and streptomycin-resistance strains and host differentiated
races of Xanthomonas campestris pv. vesicatoria in North
Carolina. Ritchie, D.F.; Dittapongpitch, V.
St. Paul, Minn. : American Phytopathological Society; 1991
Jul. Plant disease v. 75 (7): p. 733-736; 1991 Jul.  Includes
references.

Language:  English

Descriptors: North Carolina; Capsicum annuum; Lycopersicon
esculentum; Xanthomonas campestris pv. vesicatoria; Strains;
Races; Strain differences; Plant diseases; Phenotypes;
Virulence; Copper; Streptomycin; Resistance; Correlation;
Plasmids; Pest resistance


51                                     NAL Call. No.: QR1.F44
Cross-blot: a rapid screening procedure for determining
specificity of antibodies to native proteins of the brown-rot
fungus Postia placenta. Clausen, C.A.; Green, F. III; Highley,
T.L.
Amsterdam : Elsevier Science Publishers; 1991 Mar01.
FEMS microbiology letters - Federation of European
Microbiological Societies v. 78 (2/3): p. 315-318; 1991 Mar01. 
Includes references.

Language:  English

Descriptors: Wood destroying fungi; Fungal antigens;
Monoclonal antibodies; Screening; Immunoblotting; Rapid
methods

Abstract:  A method is described for rapidly screening large
numbers of mono-or polyclonal antibodies for specificity with
an equivalent number of antigens on a single sheet of
nitrocellulose paper. This method, referred to as cross-blot,
uses only 120 microliter of antigen or antibody and can be
completed in less than 6 h. Cross-blot was developed for rapid
screening of hybridoma culture supernatants and can be adapted
for use with Western blots of native and denatured proteins as
well as screening polyclonal antibodies. In this study, murine
monoclonal antibodies were produced to Postia placenta, a
brown-rot wood decay fungus. Immunizing antigens were derived
from P. placenta-decayed wood extracts. The antibodies were
screened for specificity to a number of native proteins
produced by the fungus. Cross-blot proved to an efficient
method of visualizing cross-reacting antibodies while
screening large numbers of antibodies for specificity.


52                                   NAL Call. No.: 442.8 Z34
Cross-talk between the virulence and phosphate regulons of
Agrobacterium tumefaciens caused by an unusual interaction of
the transcriptional activator with a regulatory DNA element.
Aoyama, T.; Takanami, M.; Makino, K.; Oka, A.
Berlin, W. Ger. : Springer International; 1991 Jul.
M G G : Molecular and general genetics v. 227 (3): p. 385-390;
1991 Jul. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Escherichia coli;
Transcription; Virulence; Genes; Plasmids; Gene expression;
Dna; Nucleotide sequences; Binding site; Dna binding proteins;
Genetic regulation; Promoters; Controlling elements;
Phosphates; Nutrient deficiencies; Bacterial proteins

Abstract:  Transcription of a virulence gene on the hairyroot-
inducing plasmid A4, which is induced by plant factors in
Agrobacterium tumefaciens, was also activated by phosphate
limitation in both A. tumefaciens and Escherichia coli. The
starting site of RNA synthesized under the two inducing
conditions was the same, and an identical promoter was
responsible for both inducible expressions. The response of
the virulence gene to phosphate limitation did not require the
positive regulator VirG for the virulence regulon, but
depended entirely on the presence of PhoB protein, the
positive regulator for the phosphate regulon. The DNA signal
upstream of the virulence gene, which is targeted by the VirG
protein, was recognized by the E. coli PhoB protein in vitro.
These results indicate that cross-talk between the two
regulons occurred during the recognition of a DNA signal by
the regulatory protein.


53                                   NAL Call. No.: QK725.P54
Crown gall transformation of lentil (Lens culinaris Medik.)
with virulent strains of Agrobacterium tumefaciens.
Warkentin, T.D.; McHughen, A.
Berlin, W. Ger. : Springer International; 1991.
Plant cell reports v. 10 (10): p. 489-493; 1991.  Includes
references.

Language:  English

Descriptors: Lens culinaris; Agrobacterium tumefaciens;
Genetic transformation; Virulence; Strain differences; Tumors

Abstract:  Four diverse strains of agrobacterium tumefaciens
(C58, Ach5, GV3111, and A281) were capable of inducing tumors
at a high frequency on inoculated stems of lentil (Lens
culinaris Medik. cultivar Laird) in vivo, and on excised shoot
apices in vitro. GV3111 and Ach5 produced the largest and
heaviest tumors in vivo, while A281 produced the heaviest
tumors in vitro. Tumor formation and opine production are
indicative of plant cell transformation and tumors produced
appropriate opines: nopaline (C58), octopine (Ach5 and
GV3111), and agropine and mannopine (A281). Southern analysis
of DNA from a tumor line produced by strain C58 showed that a
T-DNA fragment had been transferred into the lentil genome.


54                                   NAL Call. No.: SB599.P45
Cultivar-strain specificity between Chrysanthemum morifolium
and Agrobacterium tumefaciens.
Bush, A.L.; Pueppke, S.G.
London : Academic Press; 1991 Oct.
Physiological and molecular plant pathology v. 39 (4): p.
309-323; 1991 Oct. Includes references.

Language:  English

Descriptors: Dendranthema morifolium; Cultivars; Agrobacterium
tumefaciens; Strains; Host specificity; Molecular biology;
Strain differences; Pathogenicity; Varietal susceptibility;
Tumors; Marker genes; Beta-glucuronidase; Enzyme activity;
Gene expression; Gene transfer; Genetic transformation;
Endogenous growth regulators

Abstract:  We have examined cultivar specificity between
Chrysanthemum morifolium and Agrobacterium tumefaciens strains
Chry5 and B6. Although 42% of the 85 cultivars formed tumours
after inoculation with both strains, some cultivars formed no
tumours in response to Chry5, to B6, or to both strains. Four
cultivars were utilized to examine these interactions in a
leaf disc transformation system with a virE::lacZ fusion. We
specifically tested the hypothesis that cultivar-strain
specificity is due to differential vir gene induction by
conditioned media from the cultivars, but could find no
evidence to support this possibility. We also tested the
hypothesis that specificity is due to differential T-DNA
transfer, integration or expression. This was accomplished by
transferring into each strain a scorable marker (beta-
glucuronidase) contained between T-DNA borders. Leaf discs
then were inoculated, and expression of enzyme activity was
used to monitor transformation. Transfer of the T-DNA marker
gene followed a pattern that reflected tumorigenicity in all
cultivar-strain pairs, indicating that cultivar-strain
specificity was due to differences in the transfer of T-DNA,
or in subsequent integration processes. Analysis of the auxin
and cytokinin levels of cultivars representative of different
cultivar-strain interactions suggested that, although high
hormone levels may be associated with high tumour mass, they
do not appear to account for the innate susceptibility of a
cultivar.


55                                 NAL Call. No.: QH345.A1P73
Culture of Datura innoxia Mill transformed roots as a producer
of tropane alkaloids.
Bulgakov, V.P.; Zhuravlev, Yu.N.; Toroptseva, I.V.
New York, N.Y. : Consultants Bureau; 1991 Sep.
Applied biochemistry and microbiology v. 27 (2): p. 222-226.
ill; 1991 Sep. Translated from: Prikladnaia Biokhimiia i
Mikrobiologiia, v. 27 (2), 1991, p. 286-291. (385 P93). 
Includes references.

Language:  English; Russian

Descriptors: Datura fastuosa; Agrobacterium rhizogenes; Cell
culture; Genetic transformation; Tumors; Roots; Tropane
alkaloids; Biosynthesis; Growth


56                                   NAL Call. No.: aTP375.T4
Current productivity and future opportunities for sugarcane
agriculture from a plant breeder's perspective.
Heinz, D.J.
New Orleans : Sugar Processing Research Inc; 1991 May.
Proceedings of the ... sugar processing research conference.
p. 212-228; 1991 May.  Meeting held on May 29-June 1, 1990,
San Francisco, California. Includes references.

Language:  English

Descriptors: Saccharum officinarum; Saccharum; Crop
production; Crop yield; Cane sugar; Plant breeding; Cultivars;
Biotechnology; Genetic engineering; Plant diseases; Genetic
resistance


57                                 NAL Call. No.: QL391.N4J62
Current status of the availability, development, and use of
host plant resistance to nematodes.
Roberts, P.A.
Lake Alfred, Fla. : Society of Nematologists; 1992 Jun.
Journal of nematology v. 24 (2): p. 213-227; 1992 Jun. 
Literature review. Includes references.

Language:  English

Descriptors: Plant parasitic nematodes; Pest resistance; Plant
breeding; Genes; Inheritance; Screening; Tolerance; Literature
reviews

Abstract:  Host plant resistance (HPR) to nematodes has been
identified in many major crops and related wild germplasm.
Most HPR is to the more specialized, sedentary endoparasitic
genera and species, e.g., Globodera, Heterodera, Meloidogyne,
Nacobbus, Rotylenchulus, and Tylenchulus. Some HPR has been
developed or identified also to certain migratory
endoparasites (Aphelenchoides, Ditylenchus, Pratylenchus,
Radopholus) in a few hosts. Commercial use of HPR remains
limited, despite its benefits to crop production when deployed
appropriately. Restricted use and availability of HPR result
from problems associated with transfer of resistance into
acceptable cultivars. Difficulties occur in gene transfer to
acceptable cultivars because of incompatibility barriers to
hybridization or linkage to undesirable traits, for example in
cucurbitaceous and solanaceous crops and sugarbeet.
Specificity of HPR to only one species, or one or few
pathotypes, as it relates to resistance durability and
nematode virulence, and HPR response to abiotic factors such
as high soil temperature, also limit availability and utility.
A scheme for HPR development is presented to emphasize
nematology research and information requirements for expanding
HPR use in nematode control programs, for example in common
bean, sugarbeet, and tomato. Nonbiological factors that
influence HPR usage are discussed, including heavy reliance on
nematicide programs, low priority of nematode HPR in many
breeding programs, and insufficient breeder-nematologist
collaboration.


58                                  NAL Call. No.: QK725.P532
Cutinase is not required for fungal pathogenicity on pea.
Stahl, D.J.; Schafer, W.
Rockville, Md. : American Society of Plant Physiologists; 1992
Jun. The Plant cell v. 4 (6): p. 621-629; 1992 Jun.  Includes
references.

Language:  English

Descriptors: Pisum sativum; Nectria haematococca; Fusarium
solani f.sp. pisi; Fungal diseases; Pathogenicity; Esterases;
Structural genes; Induced mutations; Mutants; Enzyme
deficiencies; Virulence; Genetic transformation; Enzyme
activity

Abstract:  Cutinase, a fungal extracellular esterase, has been
proposed to be crucial in the early events of plant infection
by many pathogenic fungi. To test the long-standing hypothesis
that cutinase of Nectria haematococca (Fusarium solani f sp
pisi) is essential to pathogenicity, we constructed cutinase-
deficient mutants by transformation-mediated gene disruption
of the single cutinase gene of a highly virulent N.
haematococca strain. Four independent mutants were obtained
lacking a functional cutinase gene, as confirmed by gel blot
analyses and enzyme assays. Bioassays of the cutinase-
deficient strains showed no difference in pathogenicity and
virulence on pea compared to the wild type and a control
transformant. We conclude that the cutinase of N. haematococca
is not essential for the infection of pea.


59                                   NAL Call. No.: 64.8 C883
Cyclic breeding used to incorporate kernel discoloration
resistance into malting barley.
Gebhardt, D.J.; Rasmusson, D.C.; Wilcoxson, R.D.
Madison, Wis. : Crop Science Society of America; 1992 Mar.
Crop science v. 32 (2): p. 352-356; 1992 Mar.  Includes
references.

Language:  English

Descriptors: Hordeum vulgare; Plant breeding; Kernels;
Discoloration; Disease resistance; Fungal diseases; Malting
quality; Selection criteria; Inheritance; Agronomic
characteristics; Recurrent selection; Quantitative traits;
Genetic improvement; Cochliobolus sativus; Alternaria
alternata; Gibberella zeae

Abstract:  Obtaining kernel discoloration (KD) resistance in
malting barley (Hordeum vulgare L.) is an important breeding
objective in the midwestern USA. This study was undertaken to
evaluate a cyclic breeding procedure for transferring
quantitative KD resistance across a wide genetic gap, and to
obtain parental germplasm or a new cultivar having KD
resistance combined with good agronomic performance and
malting quality. Six cycles of crossing and selection were
done beginning in 1970 to incorporate KD resistance genes from
'Chevron' and CI 9539 into Minnesota barley lines. Chevron and
CI 9539 were inferior for both agronomic and quality traits.
Subsequently, 45 sixth-cycle derived lines were evaluated in
inoculated disease nurseries and in field trials to determine
whether resistance was transferred and to assess agronomic and
malting quality merit. Kernel discoloration resistance was
successfully transferred using the cyclic breeding procedure,
although the resistance level tended to be below that of the
resistance sources. The derived lines were similar to the
local cultivars Robust and Morex for agronomic and quality
traits, except for kernel plumpness, and to a lesser degree
malt extract. They showed marked overall improvement compared
with the resistance sources, Chevron and CI 9534, and a few of
the lines merit consideration as potential cultivars.
Unconscious selection was hypothesized to account for the
intermediate level of KD resistance observed in local
germplasm. In this situation, cyclic recurrent breeding
appeared to be a good choice for incorporating a quantitative
disease trait into a good genetic background.


60                                   NAL Call. No.: QK710.P62
Cytosolic localization in transgenic plants of the rolC
peptide from Agrobacterium rhizogenes.
Estruch, J.J.; Parets-Soler, A.; Schmulling, T.; Spena, A.
Dordrecht : Kluwer Academic Publishers; 1991 Sep.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 17
(3): p. 547-550; 1991 Sep. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Agrobacterium rhizogenes;
Genes; Bacterial proteins; Immunocytochemistry; Cytosol;
Leaves; Transgenics; Genetic transformation; Pathogenesis;
Plant diseases; Morphogenesis

Abstract:  The rolC gene of Agrobacterium rhizogenes codes for
a peptide with an apparent molecular weight of approximately
20 kDa. Immunolocalization of the rolC peptide, in leaves of
transgenic plants which are genetic mosaics for the expression
of the rolC gene, is restricted to the phenotypically altered
sectors. Subcellular fractionation of homogenates from 35S-
rolC transgenic leaves shows the cytosolic localization of the
rolC peptide.


61                                   NAL Call. No.: 464.8 P56
Detection and identification of Peronosclerospora sacchari in
maize by DNA hybridization.
Yao, C.L.; Magill, C.W.; Frederiksen, R.A.; Bonde, M.R.; Wang,
Y.; Wu, P.S. St. Paul, Minn. : American Phytopathological
Society; 1991 Aug. Phytopathology v. 81 (8): p. 901-905; 1991
Aug.  Includes references.

Language:  English

Descriptors: Zea mays; Peronosclerospora sacchari; Mildews;
Seedborne fungi; Dna hybridization; Dna probes; Southern
blotting; Detection; Identification; Seeds; Infections;
Restriction mapping; Restriction fragment length polymorphism;
Chemotaxonomy

Abstract:  The causal organism of an incidence of maize downy
mildew in Southern China proved difficult to classify by
standard techniques. The pathogen, subsequently identified as
Peronosclerospora sacchari, was detected by DNA hybridization
in endosperm, pericarp, and pedicel tissues, but not in
embryos of infected maize seeds. Plasmid pCLY83, which had
been selected from a P. maydis DNA library, served as the
probe. No evidence for hybridization was detected between the
probe and DNAs extracted from ten common seedborne fungi of
maize: Colletotrichum graminicola, Acremonium strictum,
Curvularia lunata, Fusarium moniliforme, Bipolaris maydis,
Macrophomina phaseolina, Rhizoctonia sp., Rhizopus sp.,
Penicillium sp., and Alternaria sp. Hybridization was also not
detected with DNAs isolated from plant tissues infected with
Sclerospora graminicola or Sclerophthora macrospora. The
hybridizing DNA of the corn pathogen from China was readily
distinguished from P. sorghi and P. maydis by differences in
EcoRI, PvuI, BamHI and HindIII restriction patterns. RFLP
patterns on blots of DNA from the plants showing symptoms of
downy mildew in this case were the same as those for P.
philippinensis and P. sacchari, now believed to be
conspecific.


62                                     NAL Call. No.: QR1.C78
Detection of several strains of the bacterium-like organism of
citrus greening disease by DNA probes.
Villechanoux, S.; Garnier, M.; Renaudin, J.; Bove, J.M.
New York, N.Y. : Springer International; 1992 Feb.
Current microbiology v. 24 (2): p. 89-95; 1992 Feb.  Includes
references.

Language:  English

Descriptors: India; Thailand; Philippines; Indonesia; China;
Taiwan; South Africa; Citrus sinensis; Catharanthus roseus;
Citrus greening; Plant pathogens; Strains; Phloem; Dna; Dna
probes; Diagnostic techniques

Abstract:  Greening disease of citrus is caused by a phloem-
restricted, bacterium-like organism (BLO). DNA was purified
from phloem tissue of periwinkle plants infected with an
Indian strain of the greening BLO, restricted with HindIII
endonuclease, and cloned in the replicative form of
bacteriophage M13mpl8. By differential hybridizations
involving DNA from healthy and infected periwinkle plants, we
have selected three recombinant phages containing BLO DNA. The
BLO DNA inserts (In-2.6, In-1.9, and In-0.6) have been
purified from the viral replicative forms and used as probes.
Southern and dot hybridizations have shown that In-2.6 and
In-1.9 recognized all asian strains tested (strains from
India, Thailand. the Philippines, Indonesia, China, and
Taiwan), but-not a South African strain. In-0.6 reacted only
with the indian BLO strain.


63                                 NAL Call. No.: 448.39 SO12
The development and use of monoclonal antibodies for detection
of Erwinia. Vernon-Shirley, M.; Burns, R.
Oxford : Blackwell Scientific Publications; 1992 Feb.
The Journal of applied bacteriology v. 72 (2): p. 97-102; 1992
Feb.  Includes references.

Language:  English

Descriptors: Erwinia carotovora subsp. atroseptica; Erwinia
carotovora subsp. carotovora; Serotypes; Plant diseases;
Bacterial antigens; Monoclonal antibodies; Elisa; Diagnostic
techniques

Abstract:  Three monoclonal antibodies (McAb), which reacted
specifically with Erwinia carotovora, were produced.
Monoclonal antibody 14/18.6 reacted with serogroup I/3390 but
not with two other serogroups of E.c. subsp. atroseptica nor
with 31 serogroups of E.c. subsp. carotovora; McAb 14/2
reacted with all 34 serogroups; and McAb 14/8.6 was as
sensitive as a commercially produced polyclonal antiserum in
detecting E.c. subsp. atroseptica by enzyme-linked
immunosorbent assay.


64                                   NAL Call. No.: 464.8 P56
Development of an immunosorbent assay for seedborne Erwinia
stewartii in corn seeds.
Lamka, G.L.; Hill, J.H.; McGee, D.C.; Braun, E.J.
St. Paul, Minn. : American Phytopathological Society; 1991
Aug. Phytopathology v. 81 (8): p. 839-846; 1991 Aug.  Includes
references.

Language:  English

Descriptors: Zea mays; Erwinia stewartii; Seeds; Infections;
Elisa; Wilts; Strains; Antibodies; Monoclonal antibodies;
Seedborne organisms; Pathogenicity

Abstract:  Specificity of polyclonal and monoclonal antibodies
generated to Erwinia stewartii was determined by testing 167
bacterial strains in enzyme-linked immunosorbent assay
(ELISA). Of these, the antibodies were positive to all 43 E.
stewartii strains tested. Reaction of the monoclonal antibody
to all other bacterial strains was negative. However, the
polyclonal antibodies reacted with seven of 105 nonpathogenic
bacteria from corn plants and seeds determined not to be
virulent E. stewartii. A double-sandwich ELISA that used the
polyclonal and monoclonal antibodies was developed to detect
E. stewartii in ground corn-seed samples. A comparison of four
ELISA procedures to detect E. stewartii in pure culture and
mixed with corn-seed tissue revealed that the most appropriate
procedure was a double-sandwich ELISA using polyclonal
antibodies for capture and monoclonal antibodies for
detection. The assay detected E. stewartii antigen in seeds
from plants inoculated with a rifampicin and nalidixic acid
tolerant strain of E. stewartii but not in seeds from
uninoculated plants. The presence of viable E. stewartii in
seeds from inoculated plants was confirmed by culture.
Analyses of 400 single seeds showed an absolute positive
correlation between recovery of bacteria and ELISA response in
eight seeds. E. stewartii was recovered from 10 other seeds
that had a negative ELISA response. Recovered bacterial
populations in nine of these 10 seeds were below the threshold
of detection by ELISA.


65                              NAL Call. No.: SB950.3.A8P535
Development of Australian passionfruit hybrids to improve
quality and disease tolerance.
Fitzell, R.D.; Peak, C.M.; Peasley, D.; Cox, G.
Victoria : R.G. Richardson; 1991.
Plant protection quarterly v. 6 (2): p. 65-67; 1991.  Includes
references.

Language:  English

Descriptors: Australia; Passiflora edulis; Plant breeding;
Commercial hybrids; Hybridization; Selection criteria; Disease
resistance; Genetic resistance; Alternaria alternata; Crop
quality; Fruits; Size; Vigor; Flavor


66                                  NAL Call. No.: QK725.P532
Developmental and pathogen-induced activation of the
Arabidopsis acidic chitinase promoter.
Samac, D.A.; Shah, D.M.
Rockville, Md. : American Society of Plant Physiologists; 1991
Oct. The Plant cell v. 3 (10): p. 1063-1072; 1991 Oct. 
Includes references.

Language:  English

Descriptors: Arabidopsis thaliana; Lycopersicon esculentum;
Alternaria solani; Phytophthora infestans; Chitinase;
Promoters; Beta-glucuronidase; Reporter genes; Chimeras; Gene
expression; Leaves; Infections; Histoenzymology; Transgenics;
Genetic transformation; Ethylene; Salicylic acid; Roots

Abstract:  Expression of the Arabidopsis acidic chitinase
promoter was investigated during plant development and in
response to inoculation with fungal pathogens. A chimeric gene
composed of 1129 bp of 5' upstream sequence from the acidic
chitinase gene was fused to the beta-glucuronidase (GUS)
coding region and used to transform Arabidopsis and tomato.
Promoter activity was monitored by histochemical and
quantitative assays of GUS activity. In healthy transgenic
plants, the acidic chitinase promoter activity was restricted
to roots, leaf vascular tissue, hydathodes, guard cells, and
anthers, whereas GUS expression was induced in mesophyll cells
surrounding lesions caused by Rhizoctonia solani infection of
transgenic Arabidopsis. In transgenic tomato plants, GUS
expression was induced around necrotic lesions caused by
Alternaria solani and Phytophthora infestans. Expression of
the acidic chitinase promoter-GUS transgene was weakly induced
by infiltrating leaves with salicylic acid. Analysis of a
series of 5' deletions of the acidic chitinase promoter in
Arabidopsis indicated that the proximal 192 bp from the
transcription initiation site was sufficient to establish both
the constitutive and induced pattern of expression. Elements
further upstream were involved in quantitative expression of
the gene. The location of a negative regulatory element was
indicated between -384 and -590 and positive regulatory
elements between -1129 and-590.


67                                   NAL Call. No.: 442.8 D49
Developmental profiles of epidermal mRNAs during the pupal-
adult molt of Tenebrio molitor and isolation of a cDNA clone
encoding an adult cuticular protein: effects of juvenile
hormone analogue.
Bouhin, H.; Charles, J.P.; Quennedey, B.; Delachambre, J.
Orlando, Fla. : Academic Press; 1992 Jan.
Developmental biology v. 149 (1): p. 112-122; 1992 Jan. 
Includes references.

Language:  English

Descriptors: Tenebrio molitor; Pupae; Adults; Cuticle;
Proteins; Protein synthesis; Translation; Messenger  RNA;
Juvenile hormone analogs; Gene expression; Metamorphosis;
Ecdysis; Immunocytochemistry

Abstract:  Changes in translatable mRNAs from the wing
epidermis of the Coleoptera Tenebrio molitor have been
investigated during metamorphosis by analysis of in vitro
translated products. Striking differences between the patterns
obtained from mRNAs extracted during pupal and adult cuticle
secretion indicated that a drastic change in gene expression
occurs during the pupal-adult transition. In addition to these
stage-specific modifications, the mRNA patterns changed within
each cuticular synthesis program (pupal or adult), especially
at ecdysis. After tritiated leucine incorporation, some of the
major radiolabeled cuticular proteins showed similar changes
suggesting that the sequential appearance of mRNAs corresponds
to sequential deposition of cuticular proteins. In
supernumerary pupae obtained after juvenile hormone analogue
(JHA) application on newly ecdysed pupae, translatable mRNA
were very similar to those of pharate pupae. The JHA seemed,
therefore, to prevent the expression of the adult program. By
immunoblotting in vitro translated products with a monoclonal
antibody recognizing an adult-specific cuticular protein, the
developmental profile of the corresponding mRNA was studied.
This mRNA was detected in anterior wing epidermis during the
first 80 hr of the pharate adult stage. Using the same
antibody, a cDNA clone was isolated from epidermal mRNA. The
hybrid selected mRNA coded for only one protein with an
apparent MW of 22 kDa which was, furthermore, recognized by
the antibody. The Northern blot analysis performed with the
clone confirmed the Western blot analysis of the in vitro
translation products. JHA application at the beginning of the
pupal-adult reprogramming prevented the appearance of this
mRNA; however, this transcript was present during the
following molting cycle. This reversibility of the JHA action
was confirmed by immunogold labeling of the cuticles formed in
treated animals.


68                                   NAL Call. No.: 448.3 J82
A diffusible compound can enhance conjugal transfer of the Ti
plasmid in Agrobacterium tumefaciens.
Zhang, L.; Kerr, A.
Washington, D.C. : American Society for Microbiology; 1991
Mar. Journal of bacteriology v. 173 (6): p. 1867-1872. ill;
1991 Mar.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Strains; Nopaline;
Octopine; Plasmids; Transfer; Genetic regulation; Temperature

Abstract:  Several octopine strains of Agrobacterium
tumefaciens were tested for Ti plasmid (pTi) transfer after
induction by 400 microgram of octopine per ml for 24 h. The
strains could be divided into two groups, transfer efficient
(Tra(e)) and transfer inefficient (Tra(ie)); the respective
rates of transfer were 0.77 X 10(-2) to 1.14 X 10(-2) and 0.33
X 10(-6) to 9.8 X 10(-6) plasmid transconjugant per donor
cell. Transfer efficiencies of Tra(ie) strains were greatly
increased when the time of induction was 72 h. A diffusible
conjugation factor (CF) that can enhance conjugal transfer of
pTi in A. tumefaciens was discovered when both Tra(e) and
Tra(ie) donor strains were induced in the same plate. The
evidence indicates that CF is a key factor affecting transfer
efficiency of pTi but is not sufficient by itself to induce
transfer. Tra(c) mutants can produce CF constitutively, and
Tra(e) strains can produce it after induction by low octopine
concentrations. The transfer efficiency of Tra(ie) strains was
greatly increased by adding CF to the induction medium. The
thermosensitive strain B6S3, which normally cannot conjugate
at temperatures above 30 degrees C, could transfer pTi
efficiently at 32 and 34 degrees C in the presence of CF.
Production of CF is dependent on the presence of pTi but
appears to be common for different opine strains; it was first
detected in octopine strains, but nopaline strains also
produced the same or a similar compound. CF is very
biologically active, affecting donor but not recipient
bacterial cells, but CF does not promote aggregation. Data
suggest that CF might be an activator or derepressor in the
conjugation system of A. tumefaciens. CF is a dialyzable small
molecule and is resistant to DNase, RNase, protease, and
heating to 100 degrees C for 10 min, but autoclaving (121
degrees C for 15 min) and alkaline treatment removed all
activity.


69                                 NAL Call. No.: aSB205.S7S6
Disease response of soybean cultivars to Phytophthora
megasperma f.sp. glycinea race 16 following gene transfer at
the Rps1 locus. Wagner, R.E.; Bernard, R.L.
Ames, Iowa : The Service; 1991.
Soybean genetics newsletter - U.S. Department of Agriculture,
Agricultural Research Service v. 18: p. 240-242; 1991. 
Includes references.

Language:  English

Descriptors: Glycine; Cultivars; Disease resistance;
Phytophthora megasperma


70                                 NAL Call. No.: 448.39 SO12
The dispersal of bacteria from leaf surfaces by water splash.
Butterworth, J.; McCartney, H.A.
Oxford : Blackwell Scientific Publications; 1991 Dec.
The Journal of applied bacteriology v. 71 (6): p. 484-496;
1991 Dec.  Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Brassica napus; Leaves;
Pseudomonas syringae; Klebsiella; Bacillus subtilis; Genetic
engineering; Plant disease control; Rain; Surfaces; Water
spreading; Bacterial count; Dispersal; Droplet studies;
Quantitative analysis

Abstract:  Advances in the techniques of genetic engineering
have made possible the use of genetically manipulated micro-
organisms (GMOs) for the control of pests and diseases. Before
GMOs can be widely used in agriculture, however, their fate
after release must be understood. Dispersal of released GMOs
will have an important influence on their action or survival
under field conditions. The object of this study was to
quantify the efficiency of rain an a means of removing and
disseminating such micro-organisms from foliar crop surfaces.
Spontaneous mutants of three species of bacteria (Pseudomonas
syringae, Klebseilla planticola and Bacillus subtilis),
resistant to the antibiotic rifampicin, were sprayed on two
plant species, french bean, Phaseolus vulgaris, and oilseed
rape, Brassica napus. The leaves from the plants were then
exposed to artificial rain and splash droplets generated by
the impact on the leaves were collected on selective nutrient
agar in Petri dishes and in sterile glass 28 ml screw-capped
bottles. The bacterial content of the splash drops was
assessed, as was the content of water which ran off the leaf
surfaces. Comparisons of the numbers of bacteria removed from
the leaves with the numbers applied prior to splashing show
that rainfall can be a very efficient means of removing
bacteria from foliar surfaces, but that most of the removed
bacteria run off to the soil. Only a small proportion was
splashed relatively short distances from the source.


71                                   NAL Call. No.: 442.8 Z34
Disruption of a Magnaporthe grisea cutinase gene.
Sweigard, J.A.; Chumley, F.G.; Valent, B.
Berlin, W. Ger. : Springer International; 1992 Mar.
M G G : Molecular and general genetics v. 232 (2): p. 183-190;
1992 Mar. Includes references.

Language:  English

Descriptors: Magnaporthe grisea; Genes; Esterases; Induced
mutations; Mutants; Genetic transformation; Cutin; Hydrolysis;
Pathogenicity; Fungal diseases; Oryza sativa; Hordeum vulgare;
Eragrostis curvula

Abstract:  Using a one-step strategy to disrupt CUT1, a gene
for cutinase, cut1- mutants were generated in two strains of
Magnaporthe grisea. One strain, pathogenic on weeping
lovegrass and barley and containing the arg3-12 mutation, was
transformed with a disruption vector in which the Aspergillus
nidulans ArgB+ gene was inserted into CUT1. Prototrophic
transformants were screened by Southern hybridization, and 3
of 53 tested contained a disrupted CUT1 gene (cut1::ArgB+). A
second strain, pathogenic on rice, was transformed with a
disruption vector in which a gene for hyg B resistance was
inserted into CUT1. Two of the 57 transformants screened by
Southern hybridization contained a disrupted CUT1 gene (cut1::
Hyg). CUT1 mRNA was not detectable in transformants that
contained a disrupted gene. Transformants with a disrupted
CUT1 gene failed to produce a cutin-inducible esterase that is
normally detected by activity staining on non-denaturing
polyacrylamide gels. Enzyme activity, measured either with
tritiated cutin or with p-nitrophenyl butyrate as a substrate,
was reduced but not eliminated in strains with a disrupted
CUT1 gene. The infection efficiency of the cut1- disruption
transformants was equal to that of the parent strains on all
three host plants. Lesions produced by these mutants had an
appearance and a sporulation rate similar to those produced by
the parent strains. We conclude that the M. grisea CUT1 gene
is not required for pathogenicity.


72                                   NAL Call. No.: 464.8 P56
Distribution and multiplication of western aster yellows
mycoplasmalike organisms in Catharanthus roseus as determined
by DNA hybridization analysis. Kuske, C.R.; Kirkpatrick, B.C.
St. Paul, Minn. : American Phytopathological Society; 1992
Apr. Phytopathology v. 82 (4): p. 457-462; 1992 Apr.  Includes
references.

Language:  English

Descriptors: Catharanthus roseus; Aster yellows; Mycoplasma-
like organisms; Disease distribution; Strains; Colonizing
ability; Detection; Dna probes; Symptomatology; Host parasite
relationships

Abstract:  Mycoplasmalike organism (MLO) specific DNA probes
derived from chromosomal or plasmid DNA of the severe strain
of western aster yellows MLO (SAY) were used to monitor the
distribution and multiplication of MLOs in periwinkle plants
infected with the SAY or dwarf strain (DAY) of the western AY
MLO. Plants were graft-inoculated, and DNA was extracted from
different regions of the inoculated plants over a 10-wk
period. DNA samples were applied to nitrocellulose membranes
and hybridized to cloned, 32P-labeled, MLO-specific DNA
probes. Relative concentration and distribution of MLOs were
determined by measuring the amount of hybridized probe.
Colonization patterns for the two AY-MLO strains were similar.
The MLOs were first detected in grafted shoots about 2 wk
before symptoms appeared. From the grafted shoots, the MLOs
moved into ungrafted shoots, and then systemically throughout
the plant. Distribution and concentration of MLOS correlated
directly with expression of virescence and proliferation
symptoms in aerial portions of the plants. MLO concentrations
were highest in symptomatic, actively growing shoots and
generally lowest in roots.


73                                   NAL Call. No.: 464.8 P56
Diversity of Xanthomonas campestris pv. citrumelo strains
associated with epidemics of citrus bacterial spot in Florida
citrus nurseries: correlation of detached leaf, monoclonal
antibody, and restriction fragment length polymorphism assays.
Gottwald, T.R.; Alvarez, A.M.; Hartung, J.S.; Benedict, A.A.
St. Paul, Minn. : American Phytopathological Society; 1991
Jul. Phytopathology v. 81 (7): p. 749-753; 1991 Jul.  Includes
references.

Language:  English

Descriptors: Florida; Citrus; Xanthomonas campestris;
Pathotypes; Strains; Strain differences; Heterogeneity;
Diversity; Virulence; Characterization; Assays; Monoclonal
antibodies; Restriction fragment length polymorphism;
Serological relationships

Abstract:  The heterogeneity of 194 previously uncharacterized
strains of Xanthomonas campestris pv. citrumelo isolated from
citrus bacterial spot epidemics in four citrus nurseries in
central Florida was evaluated by virulence reactions on
detached leaves, reaction to a panel of monoclonal antibodies
(MAbs), and reaction to a panel of restriction fragment length
polymorphism (RFLP) probes. Detached-leaf assays were
performed on the 194 strains that had been differentiated into
five serological groups based on reactions with six MAbs. A
subset of 27 strains, selected because of their diverse
reactions to MAbs and the detached-leaf assay, were
differentiated into five reaction types by RFLP analysis.
There was good agreement between serological reaction patterns
and RFLP results. Both assays were capable of distinguishing
strongly aggressive from less aggressive strains as indicated
by detached-leaf assay. In addition, MAb and RFLP assays often
detected the same unique strains within the population of
strains from individual nurseries. The assays also
differentiated groups of strains originating from different
foci of infection in one nursery.


74                                   NAL Call. No.: 442.8 G28
DNA fingerprinting and analysis of population structure in the
chestnut blight fungus, cryphonectria parasitica.
Milgroom, M.G.; Lipari, S.E.; Powell, W.A.
Baltimore, Md. : Genetics Society of America; 1992 Jun.
Genetics v. 131 (2): p. 297-306; 1992 Jun.  Includes
references.

Language:  English

Descriptors: Virginia; Cryphonectria parasitica; Dna
fingerprinting; Dna; Restriction mapping; Loci; Inheritance;
Linkage; Mutations; Dna probes; Dna hybridization;
Segregation; Population genetics; Genetic polymorphism;
Blight; Castanea sativa; Population structure

Abstract:  We analyzed DNA fingerprints in the chestnut blight
fungus, Cryphonectria parasitica, for stability, inheritance,
linkage and variability in a natural population. DNA
fingerprints resulting from hybridization with a dispersed
moderately repetitive DNA sequence of C. parasitica in plasmid
pMS5.1 hybridized to 6-17 restriction fragments per individual
isolate. In a laboratory cross and from progeny from a single
perithecium collected from a field population, the
presence/absence of 11 fragments in the laboratory cross and
12 fragments in the field progeny set segregated in 1:1
ratios. Two fragments in each progeny set cosegregated; no
other linkage was detected among the segregating fragments.
Mutations, identified by missing bands, were detected for only
one fragment in which 4 of 43 progeny lacked a band present in
both parents; no novel fragments were detected in any progeny.
All other fragments appeared to be stably inherited.
Hybridization patterns did not change during vegetative growth
or sporulation. However, fingerprint patterns of single
conidial isolates of strains EP155 and EP67 were found to be
heterogenous due to mutations that occurred during culturing
in the laboratory since these strains were first isolated in
1976-1977. In a population sample of 39 C. parasitica
isolates, we found 33 different fingerprint patterns with
pMS5.1. Most isolates differed from all other isolates by the
presence or absence of several fragments. Six fingerprint
patterns each occurred twice. Isolates with identical
fingerprints occurred in cankers on the same chestnut stems
three times; isolates within the other three pairs were
isolated from cankers more than 5 m apart. The null hypothesis
of random mating in this population could not be rejected if
the six putative clones were removed from the analysis. Thus,
a rough estimate of the clonal fraction of this population is
6 in 39 isolates (15.4%).


75                                 NAL Call. No.: SB732.6.M65
DNA hybridization between western aster yellows mycoplasmalike
organism plasmids and extrachromosomal DNA from other plant
pathogenic mycoplasmalike organisms.
Kuske, C.R.; Kirkpatrick, B.C.; Davis, M.J.; Seemuller, E. St.
Paul, Minn. : APS Press; 1991 Jan.
Molecular plant-microbe interactions : MPMI v. 4 (1): p.
75-80; 1991 Jan. Includes references.

Language:  English

Descriptors: Apium graveolens; Callistephus chinensis;
Catharanthus roseus; Oenothera; Macrosteles; Dalbulus maidis;
Mycoplasma-like organisms; Pathogenicity; Provenance; Strains;
Strain differences; Dna; Plasmids; Comparisons; Genetic
analysis; Dna hybridization; Characterization; Dna probes


76                                   NAL Call. No.: 442.8 Z34
DNA markers closely linked to nematode resistance genes in
sugar beet (Beta vulgaris L.) mapped using chromosome
additions and translocations originating from wild beets of
the Procumbentes section.
Jung, C.; Koch, R.; Fischer, F.; Brandes, A.; Wricke, G.;
Herrmann, R.G. Berlin, W. Ger. : Springer International; 1992
Mar.
M G G : Molecular and general genetics v. 232 (2): p. 271-278;
1992 Mar. Includes references.

Language:  English

Descriptors: Beta vulgaris var. saccharifera; Beta; Heterodera
schachtii; Repetitive  DNA; Genetic markers; Polymerase chain
reaction; Genetic resistance; Pest resistance; Genes; Dna
fingerprinting; Linkage; Chromosome addition; Addition lines;
Chromosome translocation; Translocation lines; Dna probes; Dna
hybridization; Gene location; Chromosomes; Gene mapping

Abstract:  Genes conferring resistance to the beet cyst
nematode (Heterodera schachtii Schm.) have been transferred to
sugar beet (Beta vulgaris L.) from three wild species of the
Procumbentes section using monosomic addition and
translocation lines, because no meiotic recombination occurs
between chromosomes of cultured and wild species. In the
course of a project to isolate the nematode resistance genes
by strategies of reverse genetics, probes were cloned from DNA
of a fragmented B. procumbens chromosome carrying a resistance
gene, which had been isolated by pulsed-field gel
electrophoresis. One probe (pRK643) hybridized with a short
dispersed repetitive DNA element, which was found only in wild
beets, and thus may be used as a molecular marker for nematode
resistance to progenies of monosomic addition lines
segregating resistant and susceptible individuals. Additional
probes for the resistance gene region were obtained with a
polymerase chain reaction (PCR)-based strategy using
repetitive primers to amplify DNA located between repetitive
elements. One of these probes established the existence of at
least six different chromosomes from wild beet species, each
conferring resistance independently of the others. A strict
correlation between the length of the wild beet chromatin
introduced in fragment addition and translocation lines and
the repeat copy number has been used physically to map the
region conferring resistance to a chromosome segment of 0.5-3
Mb.


77                                   NAL Call. No.: 448.3 AP5
DNA probes for detection of copper resistance genes in
Xanthomonas campestris pv. vesicatoria.
Garde, S.; Bender, C.L.
Washington, D.C. : American Society for Microbiology; 1991
Aug. Applied and environmental microbiology v. 57 (8): p.
2435-2439; 1991 Aug. Includes references.

Language:  English

Descriptors: Xanthomonas campestris; Genes; Resistance;
Copper; Strains; Plasmids

Abstract:  The copper resistance (Cur) genes encoded on
pXV10A, a 190-kb plasmid in Xanthomonas campestris pv.
vesicatoria XV10, were isolated on a 44-kb cosmid clone
designated pCuR1. Tn5 mutagenesis of pCuR1 indicated that a
4.0-kb region was required for copper resistance. Three
restriction fragments located within the 4.0-kb region
demonstrated high specificity for the Cur genes present in X.
campestris pv. vesicatoria and will be useful in monitoring
the presence of these genes in the environment.


78                                  NAL Call. No.: QH442.G456
DNAP announces successful trial of altered plants.
New York, N.Y. : Mary Ann Liebert; 1991 Jun.
Genetic engineering news v. 11 (6): p. 19; 1991 Jun.

Language:  English

Descriptors: U.S.A.; Nicotiana tabacum; Plant breeding;
Genetic engineering; Chitinase; Biosynthesis; Genetic
regulation; Genetic code; Plant pathogenic fungi; Genetic
resistance


79                                   NAL Call. No.: 443.8 H42
Ecological and genetic models of host-pathogen coevolution.
Frank, S.A.
Oxford : Blackwell Scientific Publications; 1991 Aug.
Heredity v. 67 (pt.1): p. 73-83; 1991 Aug.  Includes
references.

Language:  English

Descriptors: Plants; Plant pathogens; Genetic polymorphism;
Plant diseases; Evolution; Genetic models; Genetic algebras;
Virulence; Genetic resistance; Disease resistance; Gene
frequency

Abstract:  A model is presented to analyse the forces that
maintain genetic polymorphism in interactions between host
plants and their pathogens. Genetic variability in hosts
occurs for specific resistance to different pathogen races and
variability in pathogens occurs for specific virulence to
different host races. The model tracks both fluctuating
population sizes and changing gene frequencies. Analyses over
a range of parameters show that ecological and demographic
factors, such as birth and death rates, often have a more
profound effect on the amount of polymorphism than genetic
parameters, such as the pleiotropic costs of resistance and
virulence associated with different alleles. A series of
simple measures are proposed to predict the amount of genetic
polymorphism expected in particular host-pathogen
interactions. These measures can be used to develop and test a
comparative theory of genetic polymorphism in host-pathogen
coevolution.


80                                    NAL Call. No.: 1.9 P69P
Effect of disease assessment method on ranking potato
cultivars for resistance to early blight.
Christ, B.J.
St. Paul, Minn. : American Phytopathological Society; 1991
Apr. Plant disease v. 75 (4): p. 353-356; 1991 Apr.  Includes
references.

Language:  English

Descriptors: Pennsylvania; Solanum tuberosum; Alternaria
solani; Cultivars; Genetic resistance; Screening;
Pathogenicity; Symptoms


81                                     NAL Call. No.: QR1.L47
Effect of parB on plasmid stability and gene expression in
Xanthomonas campestris.
Pimenta, A. de L.; Rosato, Y.B.; Astolfi-Filho, S.
Oxford : Blackwell Scientific Publications; 1992 Jun.
Letters in applied microbiology v. 14 (6): p. 233-237; 1992
Jun.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. campestris;
Xanthomonas campestris pv. manihotis; Bacillus subtilis; Loci;
Plasmids; Stability; Gene expression; Genetic transformation;
Alpha-amylase; Reporter genes; Enzyme activity; Vectors;
Cloning


82                                    NAL Call. No.: SB599.C8
Engineering genetic disease resistance into crops:
biotechnological approaches to crop protection.
Harms, C.T.
Oxford : Butterworths-Heinemann Ltd; 1992 Aug.
Crop protection v. 11 (4): p. 291-306; 1992 Aug.  Literature
review.  Includes references.

Language:  English

Descriptors: Literature reviews; Grain crops; Horticultural
crops; Genetic engineering; Disease resistance; Genetic
resistance; Transgenics; Plant protection; Phytoalexins;
Defense mechanisms; Pathogenesis-related proteins; Genetic
improvement; Somaclonal variation; In vitro selection; In
vitro culture; Somatic hybridization


83                                   NAL Call. No.: QK710.P62
Environmental conditions differentially affect vir gene
induction in different Agrobacterium strains. Role of the VirA
sensor protein.
Turk, S.C.H.J.; Melchers, L.S.; Dulk-Ras, H. den; Regensburg-
Tunk, A.J.G.; Hooykaas, P.J.J.
Dordrecht : Kluwer Academic Publishers; 1991 Jun.
Plant molecular biology : an international journal on
fundamental research and genetic engineering v. 16 (6): p.
1051-1059; 1991 Jun.  Includes references.

Language:  English

Descriptors: Kalanchoe tubiflora; Agrobacterium tumefaciens;
Agrobacterium rhizogenes; Virulence; Genes; Gene expression;
Plasmids; Genetic regulation; Bacterial proteins; Ph; Air
temperature; Aromatic compounds; Strain differences

Abstract:  The induction of vir gene expression in different
types of Agrobacterium strains shows different pH sensitivity
profiles. The pH sensitivity pattern demonstrated by octopine
Ti strains was similar to that of a supervirulent leucinopine
Ti strain, whereas this was different from that shown by
nopaline Ti strains and agropine Ri strains. Data are given
which indicate that these differences are due to different
properties of the virA genes of these wild types. An
exceptional case was formed by strains with the limited-host-
range plasmid pTiAG57 which showed AS-dependent vir induction
only if reduced inoculum sizes were used and the temperature
was 28 degrees C or below.


84                                     NAL Call. No.: 421 C16
Eudorylas (Metadorylas) sp. (Diptera: Pipunculidae): a
previously unreported parasitoid of Dalbulus maidis (Delong
and Wolcott) and Dalbulus elimatus (Ball) (Homoptera:
Cicadellidae).
Vega, F.E.; Barbosa, P.; Panduro, A.P.
Ottawa : Entomological Society of Canada; 1991 Jan.
The Canadian entomologist v. 123 (1): p. 241-242. ill; 1991
Jan.  Includes references.

Language:  English

Descriptors: Mexico; Zea mays; Dalbulus elimatus; Dalbulus
maidis; Disease vectors; Maize rayado fino marafivirus;
Mycoplasma-like organisms; Spiroplasma kunkelii; Biological
control; Diptera; Parasites of insect pests


85                                   NAL Call. No.: 448.3 AP5
Evaluation of methods for sampling, recovery, and enumeration
of bacteria applied to the phylloplane.
Donegan, K.; Matyac, C.; Seidler, R.; Porteous, A.
Washington, D.C. : American Society for Microbiology; 1991
Jan. Applied and environmental microbiology v. 57 (1): p.
51-56; 1991 Jan. Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Avena sativa; Erwinia
herbicola; Enterobacter cloacae; Leaves; Enumeration;
Bacterial count; Sampling; Laboratory methods; Monitoring;
Genetic engineering; Pot experimentation

Abstract:  Determining the fate and survival of genetically
engineered microorganisms released into the environment
requires the development and application of accurate and
practical methods of detection and enumeration. Several
experiments were performed to examine quantitative recovery
methods that are commonly used or that have potential
applications. In these experiments, Erwinia herbicola and
Enterobacter cloacae were applied in greenhouses to Blue Lake
bush beans (Phaseolus vulgaris) and Cayuse oats (Avena
sativa). Sampling indicated that the variance in bacterial
counts among leaves increased over time and that this increase
caused an overestimation of the mean population size by bulk
leaf samples relative to single leaf samples. An increase in
the number of leaves in a bulk sample, above a minimum number,
did not significantly reduce the variance between samples.
Experiments evaluating recovery methods demonstrated that
recovery of bacteria from leaves was significantly better with
stomacher blending, than with blending, sonication, or washing
and that the recovery efficiency was constant over a range of
sample inoculum densities. Delayed processing of leaf samples,
by storage in a freezer, did not significantly lower survival
and recovery of microorganisms when storage was short term and
leaves were not stored in buffer. The drop plate technique for
enumeration of bacteria did not significantly differ from the
spread plate method. Results of these sampling, recovery, and
enumeration experiments indicate a need for increased
development and standardization of methods used by researchers
as there are significant differences among, and also important
limitations to, some of the methods used.


86                                 NAL Call. No.: QL391.N4J62
Evaluation of Nicotiana otophora as a source of resistance to
Meloidogyne incognita race 4 for tobacco.
Reed, S.M.; Schneider, S.M.
Lake Alfred, Fla. : Society of Nematologists; 1992 Jun.
Journal of nematology v. 24 (2): p. 253-256; 1992 Jun. 
Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Nicotiana; Meloidogyne
incognita; Pest resistance; Gene transfer; Genotypes;
Cultivars

Abstract:  No currently available tobacco cultivar possesses
resistance to Meloidogyne incognita race 4, nor has any source
of resistance been reported within Nicotiana tabacum. The
purpose of this study was to evaluate N. otophora acc. La
Quinta as a source of resistance to this pathogen. Plants of
tobacco cvs. NC 95 and NC 2326, N. otophora La Quinta and N.
repanda were inoculated with second-stage juveniles of M.
incognita race 4. Gall indices and egg-mass ratings were
assessed at 4 and 8 weeks after inoculation. The two N.
tabacum cultivars were heavily galled and had numerous egg
masses at both rating periods. Nicotiana repanda was only
weakly resistant. The galls on this species were very small
and present at a low to moderate level; however, egg-mass
ratings approaching those of the tobacco cultivars were
observed 8 weeks after inoculation. In contrast, low gall
indices and egg-mass ratings were found for N. otophora La
Quinta at both the 4- and 8-week rating periods. In addition,
little variability was observed within this species for either
disease rating. Therefore, it appears that the La Quinta
accession of N. otophora is a very promising source of M.
incognita race 4 resistance for transfer to N. tabacum.


87                                   NAL Call. No.: QH301.N32
Evidence for Agrobacterium-mediated genetic transformation in
Larix decidua. Huang, Y.; Shin, D.I.; Karnosky, D.F.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 233-235;
1991.  In the series analytic: Woody plant biotechnology /
edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Includes references.

Language:  English

Descriptors: Larix decidua; Gene expression; Genetic
transformation; Agrobacterium tumefaciens


88                                   NAL Call. No.: SB599.P45
Evidence for the requirement of extracellular protease in the
pathogenic interaction of Pyrenopeziza brassicae with oilseed
rape.
Ball, A.M.; Ashby, A.M.; Daniels, M.J.; Ingram, D.S.;
Johnstone, K. London : Academic Press; 1991 Feb.
Physiological and molecular plant pathology v. 38 (2): p.
147-161; 1991 Feb. Includes references.

Language:  English

Descriptors: Brassica napus var. oleifera; Pyrenopeziza
brassicae; Mutants; Strains; Pathogenicity; Proteinases;
Enzyme activity; Proteolysis; Genetic transformation; Host
parasite relationships; Molecular biology

Abstract:  Using a detached cotyledon test for pathogenicity,
a UV-induced, non-pathogenic mutant of Pyrenopeziza brassicae
was isolated which was also deficient in extracellular
protease production in vitro. The proteolytic activity in the
wild type was apparently due to a single cysteine protease
with a mol. wt of 34 k, a temperature optimum of 40 degrees C
and a pH optimum of 8. When the mutant was crossed with a
wild-type isolate of P. brassicae, the non-proteolytic and
non-pathogenic traits co-segregated in the resulting progeny.
The protease-mutant was transformed with clones from a genomic
library of P. brassicae and a transformant obtained which had
a single cosmid insert and showed concomitant restoration of
pathogenicity and proteolytic activity in vitro. These results
suggest that extracellular protease is a pathogenicity
determinant of P. brassicae and possible functions for this
protease in the disease process are discussed.


89                                 NAL Call. No.: SB732.6.M65
Evolution of agrobacteria and their Ti plasmids: a review.
Otten, L.; Canaday, J.; Gerard, J.C.; Fournier, P.; Crouzet,
P.; Paulus, F. St. Paul, Minn. : APS Press; 1992 Jul.
Molecular plant-microbe interactions : MPMI v. 5 (4): p.
279-287; 1992 Jul. Literature review.  Includes references.

Language:  English

Descriptors: Agrobacterium; Plasmids; Literature reviews;
Phylogeny; Dna; Nucleotide sequences; Genes; Comparisons;
Transposable elements; Chromosomes; Genome analysis; Plant
pathogenic bacteria


90                                     NAL Call. No.: 381 AR2
Expression cloning in Escherichia coli and preparative
isolation of the reductase coacting with chalcone synthase
during the key step in the biosynthesis of soybean
phytoalexins.
Welle, R.; Schroder, J.
Orlando, Fla. : Academic Press; 1992 Mar.
Archives of biochemistry and biophysics v. 293 (2): p.
377-381; 1992 Mar. Includes references.

Language:  English

Descriptors: Glycine max; Phytoalexins; Biosynthesis;
Naringenin-chalcone synthase; Oxidoreductases; Dna; Cloning;
Transformation; Gene expression; Genetic engineering;
Purification; Enzyme activity

Abstract:  The cDNA for the reductase involved in the
biosynthesis of 6'-deoxychalcone (4,2',4'-trihydroxychalcone),
the first specific intermediate in the pathway to soybean
phytoalexins, was cloned into the expression vector pKK233-2
and transformed into Escherichia coli. Using this source,
about 5 mg of homogeneous reductase was isolated from 45 g of
cells. The protein purification protocol differs completely
from the scheme applied to soybean cell cultures. Size, N-
terminal and specific enzyme activities were identical for the
plant and E. coli protein. The pure protein is fairly stable,
retaining 70% of initial activity after storage at 5 degrees C
during 4 weeks. This protein is used for crystallization and
in the study of its protein-protein interaction with chalcone
synthase.


91                                 NAL Call. No.: SB732.6.M65
Expression in vitro and during plant pathogenesis of the syrB
gene required for syringomycin production by Pseudomonas
syringae pv. syringae. Mo, Y.Y.; Gross, D.C.
St. Paul, Minn. : APS Press; 1991 Jan.
Molecular plant-microbe interactions : MPMI v. 4 (1): p.
28-36; 1991 Jan. Includes references.

Language:  English

Descriptors: Prunus avium; Pseudomonas syringae pv. syringae;
Pathogenesis; Mutants; Phytotoxins; Pathogenicity;
Antibiotics; Beta-galactosidase; Enzyme activity; Genes; Gene
expression; In vitro; Insertional mutagenesis; Gene transfer;
Strains; Strain differences


92                                    NAL Call. No.: QH442.B5
Expression of a barley ribosome-inactivating protein leads to
increased fungal protection in transgenic tobacco plants.
Logemann, J.; Jach, G.; Tommerup, H.; Mundy, J.; Schell, J.
New York, N.Y. : Nature Publishing Company; 1992 Mar.
Bio/technology v. 10 (3): p. 305-308; 1992 Mar.  Includes
references.

Language:  English

Descriptors: Nicotiana tabacum; Hordeum vulgare; Solanum
tuberosum; Rhizoctonia solani; Genetic transformation;
Transgenics; Gene transfer; Structural genes; Plant proteins;
Inhibitors; Translation; Ribosomes; Promoters; Genetic
regulation; Abiotic injuries; Genetic resistance; Fungal
diseases; Gene expression


93                                   NAL Call. No.: QK710.P62
Expression of a chimaeric heat-shock-inducible Agrobacterium
6b onocogene in Nicotiana rustica.
Tinland, B.; Fournier, P.; Heckel, T.; Otten, L.
Dordrecht : Kluwer Academic Publishers; 1992 Mar.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 18
(5): p. 921-930; 1992 Mar. Includes references.

Language:  English

Descriptors: Nicotiana rustica; Agrobacterium tumefaciens;
Oncogenes; Tumors; Cell division; Gene expression; Abiotic
injuries; Protoplasts; Callus; Chimeras; Heat shock proteins;
Promoters; Reporter genes; Genetic transformation; Messenger 
RNA; Heat shock; Seedling stage

Abstract:  The T-6b gene of Agrobacterium tumefaciens strain
Tm4 induces tumours on Nicotiana rustica by an as yet unknown
mechanism. These tumours cannot be regenerated into normal
plants. To study the effect of the T-6b gene product on normal
plant cells, the T-6b gene was placed under control of the
Drosophila melanogaster hsp70 heat-shock promoter and
introduced into N. rustica. Progeny of an hsp70-T-6b
transformant developed into normal plants. The inducibility of
the hsp70-T-6b construct was shown by northern analysis and by
heat-shock-dependent growth alterations on the level of whole
seedlings. Upon wounding at normal temperature conditions
hsp70-T-6b plants formed small tumours on leaves and stems.
Grafts between transformed plants and normal plants led to a
wound callus which remained limited to transformed tissues,
indicating that the T-6b gene product does not diffuse.
Protoplasts of hsp70-T-6b plants divided in the same way as
control protoplasts under standard culture conditions.
However, when protoplast cultures were started in the absence
of hormones, normal cells rapidly lost their sensitivity
towards hormones, whereas hsp70-T-6b cells remained sensitive
for a significantly longer period. Thus, the T-6b gene product
alters hormone sensitivity during the initial phases of
protoplast culture.


94                                     NAL Call. No.: QR1.F44
Expression of a subcloned alpha-amylase gene under the control
of a Xanthomonas campestris promoter.
Pimenta, A.L.; Rosato, Y.B.; Astolfi-Filho, S.
Amsterdam : Elsevier Science Publishers; 1991 Dec15.
FEMS microbiology letters - Federation of European
Microbiological Societies v. 90 (1): p. 11-18; 1991 Dec15. 
Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. campestris;
Xanthomonas campestris pv. manihotis; Promoters; Alpha-
amylase; Genes; Gene expression; Plasmids; Clones

Abstract:  Using the promoter probe pKK232-8 a 0.6-kb fragment
containing an active promoter sequence from Xanthomonas
campestris pv campestris was cloned. Two new plasmids were
constructed: (a) pAP2, which contains the amy gene from
Bacillus subtilis cloned between the EcoRI and HindIII sites
in the pMFY40 plasmid, and (b) pAP2X, obtained after
introduction of the cloned X. campestris promoter upstream
from the amy gene. These plasmids were introduced into
amylolytic and non-amylolytic strains of X. campestris pv
campestris and pv manihotis, respectively. Quantification of
alpha-amylase specific activity in liquid culture showed that
the introduction of a Xanthomonas promoter doubled the
expression of amy gene when the host strain was the pathovar
campestris but had little effect on the strain from pathovar
manihotis. This difference in the promoter activity might
indicate that the cloned promoter is specific and could be
involved in pathovar differentiation or plant-pathogen
interaction.


95                                   NAL Call. No.: 448.3 J82
Expression of Erwinia amylovora hrp genes in response to
environmental stimuli.
Wei, Z.M.; Sneath, B.J.; Beer, S.V.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Journal of bacteriology v. 174 (6): p. 1875-1882; 1992
Mar.  Includes references.

Language:  English

Descriptors: Erwinia amylovora; Genes; Gene expression;
Genetic regulation; Transcription; Ph; Temperature; Ammonium;
Nicotinic acid; Nitrogen; Amino acids; Mannitol; Fructose;
Glycerol; Sucrose; Glucose; Maltose

Abstract:  Seven hrp loci that are essential for the
hypersensitive reaction elicited by Erwinia amylovora were
transcriptionally fused with a derivative of transposon Tn5,
containing the promoterless Escherichia coli beta-
glucuronidase reporter gene. The seven hrp fusions were used
to monitor expression of the hrp loci in vitro and in planta.
No significant expression was detected in rich medium for any
of the fusions. However, five of them were expressed highly in
planta and in inducing medium that contains mannitol, salts,
and 5 mM (NH4)2SO4. Expression of these five hrp loci is
regulated by ammonium, nicotinic acid, complex-nitrogen
sources, certain carbon sources, temperature, and pH. Under
well-defined conditions, i.e., in inducing medium, no specific
plant components were required for transcriptional activation
of the hrp loci. The high levels of expression detected in
vitro were comparable to those determined during the
development of the hypersensitive reaction in tobacco.
Differential levels of expression of the hrp loci occurred in
host and nonhost plants. In pear, a host plant, expression of
the hrp loci was delayed and greatly reduced compared with
expression in tobacco leaves, a nonhost.


96                                   NAL Call. No.: 448.3 J82
Expression of the avirulence gene avrBs3 from Xanthomonas
campestris pv. vesicatoria is not under the control of hrp
genes and is independent of plant factors.
Knoop, V.; Staskawicz, B.; Bonas, U.
Washington, D.C. : American Society for Microbiology; 1991
Nov. Journal of bacteriology v. 173 (22): p. 7142-7150; 1991
Nov.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. vesicatoria; Genes;
Gene expression; Plasmids; Capsicum annuum; Genetic regulation

Abstract:  The avirulence gene avrBs3 from Xanthomonas
campestris pv. vesicatoria pepper race 1 is responsible for
the induction of a race-specific hypersensitive reaction in
resistant pepper cultivars. A DNA region of 3.7 kb, containing
several open reading frames and an internal repetitive region,
was shown previously to be necessary for avirulence activity
(U. Bonas, R. E. Stall, and B. Staskawicz, Mol. Gen. Genet.
218:127-136, 1989). The promoter of avrBs3 was identified by
using gene fusions to beta-glucuronidase. Also, we mapped the
transcription start site and showed that the avrBs3 gene is
expressed constitutively in cells grown in minimal or complex
medium and in planta. Polyclonal antibodies raised against a
fusion protein produced in Escherichia coli allowed the
identification of a 122-kDa protein in X. campestris pv.
vesicatoria cells expressing the avrBs3 gene. The antibody is
specific for AvrBs3 in X. campestris pv. vesicatoria cells but
also recognizes homologous proteins in other pathovars of X.
campestris. We found that AvrBs3 is localized intracellularly
in X. campestris pv. vesicatoria and is mainly in the soluble
fraction. The effect of mutations in the hrp gene cluster on
the function of AvrBs3 was examined. Expression of AvrBs3 in
X. campestris pv. vesicatoria grown in minimal or complex
medium is independent of the hrp gene cluster that determines
pathogenicity and hypersensitivity to X. campestris pv.
vesicatoria. In the plant, however, the hrp genes are required
for elicitation of a race-specific resistance response.


97                                   NAL Call. No.: 448.3 AP5
Expression of the Escherichia coli beta-glucuronidase gene in
Pseudocercosporella herpotrichoides.
Bunkers, G.J.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Applied and environmental microbiology v. 57 (10): p.
2896-2900; 1991 Oct. Includes references.

Language:  English

Descriptors: Pseudocercosporella herpotrichoides; Genetic
analysis; Genetic transformation; Escherichia coli; Beta-
glucuronidase; Enzyme activity; Gene expression; Genetic
markers; Plant pathogens; Hordeum vulgare; Triticum aestivum;
Secale cereale

Abstract:  The plant-pathogenic fungus Pseudocercosporella
herpotrichoides has been successfully transformed by using two
different positive selection systems in combination with the
Escherichia coli gusA gene. The selectable markers used in
this study were the hygromycin B phosphotransferase gene (hph)
from E. coli and the gene (bml) for beta-tubulin from a
benomyl-resistant mutant of Neurospora crassa. A lower
transformation rate was obtained with the bml system than with
the hph system. Conversely, cotransformation frequencies, as
determined with medium plates containing the chromogenic
substrate 5-bromo-4-chloro-3-indolyl-beta-D-glucuronic acid,
were higher with bml than with hph as the selectable marker.
The hygromycin-resistant transformants were mitotically
stable, and both the selectable gene and gusA were maintained
through conidiation. The vector DNA was integrated into the
genome, and the number and sites of insertion varied among
transformants. Enzyme assays of mycelial extracts showed that
beta-glucuronidase activity was highest in transformants with
a high gusA copy number. Expression of gusA during growth of
the fungus on plants was easily detectable and did not affect
pathogenicity. These results form the basis for construction
of a versatile and sensitive reporter gene system for P.
herpotrichoides.


98                                   NAL Call. No.: 448.3 J82
Extracellular secretion of pectate lyase by the Erwinia
chrysanthemi out pathway is dependent upon Sec-mediated export
across the inner membrane. He, S.Y.; Schoedel, C.; Chatterjee,
A.K.; Collmer, A.
Washington, D.C. : American Society for Microbiology; 1991
Jul. Journal of bacteriology v. 173 (14): p. 4310-4317; 1991
Jul.  Includes references.

Language:  English

Descriptors: Erwinia chrysanthemi; Pectate lyase; Secretion;
Plasma membranes; Cell membranes; Genes; Bacterial proteins;
Genetic engineering; Cell structure; Alkaline phosphatase

Abstract:  The plant pathogenic enterobacterium Erwinia
chrysanthemi EC16 secretes several extracellular, plant cell
wall-degrading enzymes, including pectate lyase isozyme PelE.
Secretion kinetics of 35S-labeled PelE indicated that the
precursor of PelE was rapidly processed by the removal of the
amino-terminal signal peptide and that the resulting mature
PelE remained cell bound for less than 60 s before being
secreted to the bacterial medium. PelE-PhoA (alkaline
phosphatase) hybrid proteins generated in vivo by TnphoA
insertions were mostly localized in the periplasm of E.
chrysanthemi, and one hybrid protein was observed to be
associated with the outer membrane of E. chrysanthemi in an
out gene-dependent manner. A gene fusion resulting in the
substitution of the beta-lactamase signal peptide for the
first six amino acids of the PelE signal peptide did not
prevent processing or secretion of PelE in E. chrysanthemi.
When pelE was overexpressed, mature PelE protein accumulated
in the periplasm rather than the cytoplasm in cells of E.
chrysanthemi and Escherichia coli MC4100 (pCPP2006), which
harbors a functional cluster of E. chrysanthemi out genes.
Removal of the signal peptide from pre-PelE was SecA dependent
in E. coli MM52 even in the presence of the out gene cluster.
These data indicate that the extracellular secretion of pectic
enzymes by E. chrysanthemi is an extension of the Sec-
dependent pathway for general export of proteins across the
bacterial inner membrane.


99                                   NAL Call. No.: SB599.C35
Extrachromosomal DNA elements of plant pathogenic
mycoplasmalike organisms. Denes, A.S.; Sinha, R.C.
Guelph, Ont. : Canadian Phytopathological Society; 1991.
Canadian journal of plant pathology; Revue Canadienne de
phytopathologie v. 13 (1): p. 26-32; 1991.  Includes
references.

Language:  English

Descriptors: Callistephus chinensis; Mycoplasma-like
organisms; Genetic analysis; Dna; Molecular weight; Plasmids;
Strains; Strain differences; Nucleotide sequences;
Characterization; Patterns; Dna hybridization


100                                  NAL Call. No.: 442.8 G28
Extrachromosomal recombination is deranged in the rec2 mutant
of Ustilago maydis.
Fotheringham, S.; Holloman, W.K.
Baltimore, Md. : Genetics Society of America; 1991 Dec.
Genetics v. 129 (4): p. 1053-1060; 1991 Dec.  Includes
references.

Language:  English

Descriptors: Ustilago zeae; Plasmids; Recombination; Mutants;
Genetic transformation

Abstract:  Transformation of a leu1 auxotroph of Ustilago
maydis to prototrophy with an autonomously replicating plasmid
containing the selectable LEU1 gene was found to be efficient
regardless of whether the transforming DNA was circular or
linear. When pairs of autonomously replicating plasmids
bearing noncomplementing leu1 alleles were used to cotransform
strains deleted entirely for the genomic copy of the LEU1
gene, Leu+ transformants were observed to arise by
extrachromosomal recombination. The frequency of recombination
increased severalfold when one plasmid of the pair was made
linear by cleavage at one end of the leu1 gene, but increased
10-100-fold when both plasmids were first made linear. The
increase in recombination noted in wild-type and rec1 strains
was not apparent in the rec2 mutant unless the members of the
pair of plasmids were cut at opposite ends of the leu1 gene to
yield linear molecules offset in only one of the two possible
configurations. Use of a pair of plasmid substrates designed
to measure nonreciprocal and multiple exchange events revealed
only a minor fraction of the total events arise through these
modes, and further that no stimulation occurred when the
plasmid DNA was linear. It is unlikely that the defect in rec2
lies in a mismatch correction step since a high yield of Leu+
recombinants was obtained from the rec2 mutant when it was
transformed with heteroduplex DNA constructed from plasmids
with the two different leu1 alleles.


101                                  NAL Call. No.: QK725.P54
Factors influencing the efficiency of T-DNA transfer during
co-cultivation of Antirrhinum majus with Agrobacterium
tumefaciens.
Holford, P.; Hernandez, N.; Newbury, H.J.
Berlin, W. Ger. : Springer International; 1992 May.
Plant cell reports v. 11 (4): p. 196-199; 1992 May.  Includes
references.

Language:  English

Descriptors: Antirrhinum majus; Cultivars; Cell culture;
Culture media; Gene transfer; Genetic transformation; Tumors;
Tissue culture; Agrobacterium tumefaciens; Strains; Virulence

Abstract:  The effects of varying the pH of the co-cultivation
medium, additions of vir-inducing phenolic compounds and the
strains of wild-type agrobacteria on transformation rates of a
number of different varieties of Antirrhinum majus were
studied. In general, optimal transformation was found with
strains C58 or A281 and was favoured by low pH and the
inclusion of acetosyringone in the co-cultivation medium.
However, maximal transformation of the least susceptible
variety was achieved at high pH and in the presence of
syringaldehyde. This demonstrates the need for the
optimization of a wide range of culture conditions when
working with new genotypes and offers a rational approach
towards the development of Agrobacterium-mediated
transformation of new species or varieties.


102                                  NAL Call. No.: QH506.E46
Fasciation induction by the phytopathogen Rhodococcus fascians
depends upon a linear plasmid encoding a cytokinin synthase
gene.
Crespi, M.; Messens, E.; Caplan, A.B.; Montagu, M. van;
Desomer, J. Oxford, Eng. : IRL Press; 1992 Mar.
The EMBO journal - European Molecular Biology Organization v.
11 (3): p. 795-804; 1992 Mar.  Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Rhodococcus fascians;
Plasmids; Transferases; Genes; Loci; Galls; Leaves; Virulence;
Fasciation; Restriction mapping; Mutants; Gene expression;
Nucleotide sequences; Amino acid sequences

Abstract:  Rhodococcus fascians is a nocardiform bacteria that
induces leafy galls (fasciation) on dicotyledonous and several
monocotyledonous plants. The wild-type strain D188 contained a
conjugative, 200 kb linear extrachromosomal element, pFiD188.
Linear plasmid-cured strains were avirulent and reintroduction
of this linear element restored virulence. Pulsed field
electrophoresis indicated that the chromosome might also be a
linear molecule of 4 megabases. Three loci involved in
phytopathogenicity have been identified by insertion
mutagenesis of this Fi plasmid. Inactivation of the fas locus
resulted in avirulent strains, whereas insertions in the two
other loci affected the degree of virulence, yielding
attenuated (aft) and hypervirulent (hyp) bacteria. One of the
genes within the fas locus encoded an isopentenyltranferase
(IPT) with low homology to analogous proteins from Gram-
negative phytopathogenic bacteria. IPT activity was detected
after expression of this protein in Escherichia coli cells. In
R. fascians, ipt expression could only be detected in bacteria
induced with extracts from fasciated tissue. R. fascians
strains without the linear plasmid but containing this fas
locus alone could not provoke any phenotype on plants,
indicating additional genes from the linear plasmid were also
essential for virulence. These studies, the first genetic
analysis of the interaction of a Gram-positive bacterium with
plants, suggest that a novel mechanism for plant tumour
induction has evolved in R. fascians independently from the
other branches of the eubacteria.


103                                  NAL Call. No.: 448.3 AP5
Fate of DNA encoding hygromycin resistance after meiosis in
transformed strains of Gibberella fujikuroi (Fusarium
moniliforme).
Leslie, J.F.; Dickman, M.B.
Washington, D.C. : American Society for Microbiology; 1991
May. Applied and environmental microbiology v. 57 (5): p.
1423-1429; 1991 May. Includes references.

Language:  English

Descriptors: Gibberella fujikuroi; Meiosis; Genetic
transformation; Hygromycin b; Drug resistance; Stability;
Inheritance

Abstract:  Stability of foreign DNA transformed into a novel
host is an important parameter in decisions to permit the
release of genetically engineered microorganisms into the
environment. Meiotic instability of transformed DNA has been
reported in fungi such as Ascobolus, Aspergillus, and
Neurospora. We used strains of Gibberella fujikuroi (Fusarium
moniliforme) transformed with the hygr gene from Escherichia
coli to study meiotic stability of foreign DNA in this plant
pathogenic fungus. Crosses with single-copy transformants
segregated hygr:hygs in a 1:1 manner consistent with that
expected for a Mendelian locus in a haploid organism.
Multicopy transformants, however, segregated hygr:hygs in a
1:2 manner that was not consistent with Mendelian expectations
for a chromosomal marker, even though two unrelated
auxotrophic nuclear genes were segregating normally.
Segregation ratios in crosses in which hygr was introduced via
the male parent did not differ significantly from crosses in
which the transformed strain served as the female parent. Some
of the sensitive progeny from the crosses with the multicopy
transformants carried hygr sequences. When these
phenotypically sensitive progeny were crossed with a wild-type
strain that carried no hygr sequences, some of the progeny
were phenotypically hygr. Some progeny from some crosses were
more resistant to hygromycin than were their sibs or the
transformant strains that served as their parents.
Transformants passaged through a maize plant only rarely
segregated progeny with the high levels of resistance. The
mechanism underlying these genetic instabilities is not clear
but may involve unequal crossing over or methylation or both.
Further work with cloned genes with homology to sequences
already present in the Fusarium genome is warranted.


104                                 NAL Call. No.: QL461.E532
Field detection of X-disease mycoplasmalike organism in
Paraphlepsius irroratus (Say) (Homoptera: Cicadellidae) using
a DNA probe. Rahardja, U.; Whalon, M.E.; Garcia-Salazar, C.;
Yan, Y.T. Lanham, Md. : Entomological Society of America; 1992
Feb. Environmental entomology v. 21 (1): p. 81-88. ill; 1992
Feb.  Includes references.

Language:  English

Descriptors: Michigan; Prunus avium; Prunus persica;
Cicadellidae; Disease vectors; Mycoplasma-like organisms;
Seasonal variation; Geographical distribution

Abstract:  The seasonal and geographic distribution of X-
diseased Paraphlepsius irroratus (Say) was studied in south,
central, and northwest Michigan in 1988 and 1989 using a DNA
probe. C6c, a fragment of pWX1 derived from infected
Colladonus montanus (Van Duzee), detected eastern X-disease in
diseased P. irroratus. Maximum numbers of infected leafhoppers
were detected at the beginning of the emergence of each
generation in early June and in late September. In early
summer the percentage of X-diseased leafhoppers at the various
sites ranged from 12.2 to 43.3%, and in the late season from
3.3 to 36.4%. The X-diseased leafhoppers occurred only in
south and central Michigan.


105                               NAL Call. No.: TP248.2.B562
Field testing of genetically engineered microorganisms.
Drahos, D.J.
Oxford : Pergamon Press; 1991.
Biotechnology advances v. 9 (2): p. 157-171; 1991.  Includes
references.

Language:  English

Descriptors: Uk; Australia; California; South Carolina;
Washington; Montana; Indiana; Maryland; Nebraska; Illinois;
Minnesota; Wisconsin; Mississippi; Plant pathogenic bacteria;
Soil bacteria; Field tests; Genetic engineering; Genetic
transformation; Recombination; Genes; Modification; Marker
genes; Gene expression; Persistence; Risk; Assessment;
Biological control; Endotoxins; Nitrogen fixation;
Baculovirus; Migration; Reviews


106                                  NAL Call. No.: 448.3 J82
First step toward a virus-derived vector for gene cloning and
expression in spiroplasmas, organisms which read UGA as a
tryptophan codon: synthesis of chloramphenicol
acetyltransferase in Spiroplasma citri.
Stamburski, C.; Renaudin, J.; Bove, J.M.
Washington, D.C. : American Society for Microbiology; 1991
Apr. Journal of bacteriology v. 173 (7): p. 2225-2230; 1991
Apr.  Includes references.

Language:  English

Descriptors: Spiroplasma citri; Bacteriophages; Escherichia
coli; Vectors; Cloning; Chloramphenicol acetyltransferase;
Reporter genes; Transfection; Transcription; Initiation; Gene
expression; Messenger  RNA; Nucleotide sequences; Genetic
code; Genetic transformation; Dna; Tryptophan

Abstract:  Spiroplasmas are wall-less procaryotes in which the
UGA codon serves not as a stop signal but as a code for the
amino acid tryptophan. Spiroplasma genes that contain UGA
codons thus cannot be studied in the usual Escherichia coli
cloning and expression systems. Although this problem can be
circumvented by using UGA-suppressor strains of E. coli,
spiroplasmas themselves would provide a more efficient cloning
and expression host. We have now successfully employed the
replicative form (RF) of a filamentous spiroplasma virus
(SpV1) to clone and express the E. coli-derived
chloramphenicol acetyltransferase (CAT) gene in Spiroplasma
citri. The CAT gene was inserted in one of the four intergenic
regions of the SpV1 RF and introduced into cells by
electroporation. Both the RF and the virion DNA produced by
the transfected cells contained the CAT gene sequences.
Northern blot analysis, primer extension, and S1 mapping
showed that transcription of the CAT gene started from a
promoter located on the SpV1 RF and was terminated downstream
of the CAT gene, still within the viral RF. Expression of the
CAT gene was demonstrated by acetylation of chloramphenicol by
cell-free extracts from the transfected spiroplasmas.


107                                  NAL Call. No.: 448.3 J82
Formation of bacterial membrane ice-nucleating
lipoglycoprotein complexes. Kozloff, L.M.; Turner, M.A.;
Arellano, F.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Journal of bacteriology v. 173 (20): p. 6528-6536; 1991
Oct.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae; Erwinia herbicola; Ice;
Nucleation; Temperature; Proteins; Phosphatidylinositols;
Mannose; Glucosamine; Galactose; Glycoproteins

Abstract:  The preliminary finding that nonprotein additions
to the protein product of the ice-nucleating gene of
Pseudomonas syringae or Erwinia herbicola are essential for
ice nucleation at the warmest temperatures has led to
experiments aimed at identifying possible linkages between the
ice protein and the other components. It appears that the
protein is coupled to various sugars through N- and O-glycan
linkages. Mannose residues are apparently bound via an N-
glycan bond to the amide nitrogen of one or more of the three
essential asparagine residues in the unique amino-terminal
portion of the protein. In turn, these mannose residues are
involved in the subsequent attachment of phosphatidylinositol
to the nucleation structure. This phosphatidylinositol-
mannose-protein structure is the critical element in the class
A nucleating structure. in addition to sugars attached to the
asparagine residues, additional sugar residues appear to be
attached by O-glycan linkages to serine and threonine residues
in the primary repeating octapeptide, which makes up 70% of
the total ice protein. These additional sugar residues include
galactose and glucosamine and most likely additional mannose
residues. These conclusions were based on (i) the changes in
ice-nucleating activity due to the action of N- and O-
glycanases, alpha- and beta-mannosidoses, and beta-
galactosidase; (ii) immunoblot analyses of ice proteins in
cell extracts after enzyme treatments; and (iii) the
properties of transformed Ice+ Escherichia coli cells
containing plasmids with defined amino-terminal and carboxyl-
terminal deletions in the ice gene. Finally, evidence is
presented that these sugar residues may play a role in
aggregating the ice gene lipoglycoprotein compound into larger
aggregates, which are the most effective ice nucleation
structures.


108                                  NAL Call. No.: 442.8 Z34
Fot1, a new family of fungal transposable elements.
Daboussi, M.J.; Langin, T.; Brygoo, Y.
Berlin, W. Ger. : Springer International; 1992 Mar.
M G G : Molecular and general genetics v. 232 (1): p. 12-16;
1992 Mar. Includes references.

Language:  English

Descriptors: Fusarium oxysporum; Transposable elements;
Nucleotide sequences; Repetitive  DNA; Genetic change;
Mutations; Nitrate reductase; Structural genes; Insertional
mutagenesis; Amino acid sequences; Restriction mapping

Abstract:  We report here the discovery of a family of
transposable elements, which we refer to as Fot1 elements, in
the fungal plant pathogen Fusarium oxysporum. The first
element was identified as an insertion in the gene encoding
nitrate reductase. It is 1928 bp long, has 44 bp inverted
terminal repeats, contains a large open reading frame and is
flanked by a 2 bp (TA) target site duplication. This element
shares significant structural similarities with a class of
transposons that includes Tc1 from Caenorhabditis elegans and
therefore represents a new class of transposable elements in
fungi.


109                                NAL Call. No.: SB732.6.M65
Further characterization of an hrp gene cluster of Erwinia
amylovora. Bauer, D.W.; Beer, S.V.
St. Paul, Minn. : APS Press; 1991 Sep.
Molecular plant-microbe interactions : MPMI v. 4 (5): p.
493-499; 1991 Sep. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Pyrus communis; Erwinia
amylovora; Strains; Mutants; Host parasite relationships;
Pathogenicity; Strain differences; Genes; Pathogenesis; Stress
response; Plasmids; Cosmids


110                                  NAL Call. No.: QK600.M82
Gall development in hairy root cultures infected with
Plasmodiophora brassicae.
Graveland, R.; Dale, P.; Mithen, R.
Cambridge : Cambridge University Press; 1992 Mar.
Mycological research v. 96 (pt.3): p. 225-228; 1992 Mar. 
Includes references.

Language:  English

Descriptors: Brassica napus; Agrobacterium rhizogenes;
Transgenics; Plant pathogenic fungi; Galls; Developmental
stages; Plant anatomy


111                                 NAL Call. No.: 464.8 P692
Gametic disequilibria between virulence genes in barley
powdery mildew populations in relation to selection and
recombination. I. Models. Ostergard, H.; Hovmoller, M.S.
Oxford : Blackwell Scientific Publications; 1991 Jun.
Plant pathology v. 40 (2): p. 166-177; 1991 Jun.  Includes
references.

Language:  English

Descriptors: Hordeum vulgare; Erysiphe graminis; Mildews;
Genetic models; Genetic algebras; Virulence; Genes; Linkage
disequilibrium; Genetic resistance; Disease resistance;
Recombination; Natural selection; Genotypes; Gene frequency;
Cultivars; Population genetics

Abstract:  Two- and three-locus models were developed to study
the dynamics of gametic disequilibria (linkage disequilibria)
between virulence genes in an aerial population of a haploid,
biotrophic pathogen. illustrated by the fungus Erysiphe
graminis f.sp. hordei. The models predicted that selection
induced by two or three resistance genes in host varieties
would generate gametic disequilibria between the corresponding
virulence genes and that recombination taking place during
sexual reproduction in most cases would reduce the amount of
gametic disequilibrium attained by selection. The reduction of
gametic disequilibrium during sexual reproduction depended on
the recombination frequency multiplied by the proportion of
spores produced by sexual reproduction and by the relative
acreage of varieties on which the virulence genes considered
were 'unnecessary'. The dynamics of gametic disequilibria in
the aerial population were shown to be different depending on
the use of resistance genes in host varieties. Two resistance
genes present mainly in different varieties would generate
negative gametic disequilibrium between the corresponding
virulence genes, whereas two resistance genes present mainly
in the same variety would generate positive gametic
disequilibrium between the corresponding virulence genes. In
both cases, the signs would be maintained as predicted until
the virulence genes became fixed. However, if the
disequilibrium initially was non-zero with a sign opposite to
that predicted from the distribution of the varieties, then
the sign of the disequilibrium would not change
instantaneously. These general results were valid for sexual
as well as asexual reproduction. The predictions of the models
were largely in accordance with those observed in Danish
barley powdery mildew populations (Hovmoller & Ostergard,
1991). The results of the models were complemented by
numerical studies to illustrate the dynamics of gametic
disequilibria in specific cases, and to demonstrate th


112                                 NAL Call. No.: 464.8 P692
Gametic disequilibria between virulence genes in barley
powdery mildew populations in relation to selection and
recombination. II. Danish observations.
Hovmoller, M.S.; Ostergard, H.
Oxford : Blackwell Scientific Publications; 1991 Jun.
Plant pathology v. 40 (2): p. 178-189; 1991 Jun.  Includes
references.

Language:  English

Descriptors: Jutland; Fyn; Denmark; Hordeum vulgare; Erysiphe
graminis; Mildews; Linkage disequilibrium; Virulence; Genes;
Natural selection; Recombination; Genotypes; Population
genetics; Disease resistance; Genetic resistance; Cultivars;
Genetic variation; Line differences; Geographical distribution

Abstract:  Analyses of gametic disequilibria (linkage
disequilibria) between virulence genes were carried out on 14
samples of Erysiphe graminis f.sp. hordei collected from the
aerial population at six Danish localities from 1985 to 1988.
in most samples, the virulence genotypes Va7Va12, Va9Va12,
Va12Vk, Va7V(La), VkV(La) and VhV(La) were significantly less
frequent than the product of the corresponding gene
frequencies (negative gametic disequilibrium), while the
virulence genotypes Va7Vk, Va9Vk, Va6Vh, Va7Vh and VkVh, were
significantly more frequent than the product of the
corresponding gene frequencies (positive gametic
disequilibrium). These results could largely be explained by
the distribution of powdery mildew resistance genes in the
barley varieties grown in Denmark. Selection forces induced by
two resistance genes present mainly in different varieties
were likely to generate negative gametic disequilibrium
between the corresponding virulence genes, whereas selection
forces induced by two resistance genes present mainly in the
same variety were likely to generate positive gametic
disequilibrium between the corresponding virulence genes. This
pattern was in accordance with that predicted from two- and
three-locus models comprising recombination and selection
induced by host resistance genes (Ostergard & Hovmoller,
1991). It was concluded that such a model system is necessary
for designing an ideal strategy for the deployment of
varieties (resistance genes), and that the signs of gametic
disequilibria do not provide adequate information for that
purpose.


113                                 NAL Call. No.: QH431.G452
Gamma irradiation induced in an alien chromosome segment of
the wheat 'Indis' and their use in gene mapping.
Marais, G.F.
Ottawa : National Research Council of Canada; 1992 Apr.
Genome v. 35 (2): p. 225-229; 1992 Apr.  Includes references.

Language:  English

Descriptors: Triticum aestivum; Thinopyrum; Deletions;
Chromosome translocation; Translocation lines; Irradiation;
Gamma radiation; Mutants; Induced mutations; Gene mapping;
Gene transfer; Genetic markers; Cultivars; Genetic resistance;
Rust diseases

Abstract:  Deletion mutants were produced in a translocated
chromosome segment derived from Thinopyrum distichum (Thunb.)
Love. Spikes of the translocation line 'Indis' were irradiated
with gamma rays at dosages of 15, 20, and 25 Gy. The
irradiated spikes were pollinated with 'Inia 66' pollen and
the F2 and F3 generations screened for translocation mutants,
using the genes for leaf rust resistance and yellow endosperm
pigmentation as markers. Finally, endopeptidase polymorphisms
were utilized to select mutant translocation homozygotes
within each of 29 families. An investigation of polymorphisms
at the alpha-Amy-D2 and Wsp-D1 loci of chromosome arm 7DL
revealed that 'Indis' did not produce an alpha-AMY-D2 product,
but it did produce a novel WSP-D1 protein. The mutants were
characterized for their leaf and stem rust resistances and the
presence of WSP-D1 and yellow flour pigments. The stem rust
resistance gene could not be accurately mapped. The linear
order of the remaining loci on 7DL was centromere--leaf rust
resistance--Wsp-D1 and yellow pigment. The data obtained
suggested that the 'Indis' translocation has homo(eo)logy to
the Lr19 translocation and homoeology to 7DL of common wheat.


114                                  NAL Call. No.: 448.3 J82
A gene cluster required for coordinated biosynthesis of
lipopolysaccharide and extracellular polysaccharide also
affects virulence of Pseudomonas solanacearum.
Kao, C.C.; Sequeira, L.
Washington, D.C. : American Society for Microbiology; 1991
Dec. Journal of bacteriology v. 173 (24): p. 7841-7847; 1991
Dec.  Includes references.

Language:  English

Descriptors: Pseudomonas solanacearum; Genes; Biosynthesis;
Polysaccharides; Lipopolysaccharides; Pathogenesis; Virulence

Abstract:  Bacterial cell surface components can be important
determinants of virulence. At least three gene clusters
important for extracellular polysaccharide (EPS) biosynthesis
have been previously identified in the plant pathogen
Pseudomonas solanacearum. We have found that one of these gene
clusters, named ops, is also required for lipopolysaccharide
(LPS) biosynthesis. Mutations in any complementation unit of
this cluster decreased EPS production, prevented the binding
of an LPS-specific phage, and altered the mobility of purified
LPS in sodium dodecyl sulfate-polyacrylamide gel
electrophoresis. However, restoration of LPS biosynthesis
alone was not sufficient to restore virulence to the wild-type
level, suggesting that EPS is important for pathogenesis.


115                                NAL Call. No.: SB732.6.M65
Gene-for-gene interactions between Pseudomonas syringae pv.
phaseolicola and Phaseolus.
Jenner, C.; Hitchin, E.; Mansfield, J.; Walters, K.;
Betteridge, P.; Teverson, D.; Taylor, J.
St. Paul, Minn. : APS Press; 1991 Nov.
Molecular plant-microbe interactions : MPMI v. 4 (6): p.
553-562; 1991 Nov. Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Pseudomonas; Pathotypes;
Pseudomonas syringae pv. phaseolicola; Physiological races;
Host specificity; Cultivars; Varietal susceptibility;
Virulence; Phenotypes; Genes; Insertional mutagenesis; Gene
expression; Amino acid sequences; Nucleotide sequences


116                                  NAL Call. No.: 448.3 AP5
Genetic analysis of the antifungal activity of a soilborne
Pseudomonas aureofaciens strain.
Vincent, M.N.; Harrison, L.A.; Brackin, J.M.; Kovacevich,
P.A.; Mukerji, P.; Weller, D.M.; Pierson, E.A.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Applied and environmental microbiology v. 57 (10): p.
2928-2934; 1991 Oct. Includes references.

Language:  English

Descriptors: Pseudomonas; Biological control agents; Cosmids;
Genetic analysis; Antifungal properties; Gaeumannomyces
graminis; Rhizoctonia solani; Pythium ultimum

Abstract:  Pseudomonas aureofaciens Q2-87 produces the
antibiotic 2,4-diacetophloroglucinol (Phl), which inhibits
Gaeumannomyces graminis var. tritici and other fungi in vitro.
Strain Q2-87 also provides biological control of take-all, a
root disease of wheat caused by this fungus. To assess the
role of Phl in the antifungal activity of strain Q2-87, a
genetic analysis of antibiotic production was conducted. Two
mutants of Q2-87 with altered antifungal activity were
isolated by site-directed mutagenesis with Tn5. One mutant,
Q2-87::TN5-1, did not inhibit G. graminis var. tritici in
vitro and did not produce Phl. Two cosmids were isolated from
a genomic library of the wild-type strain by probing with the
mutant genomic fragment. Antifungal activity and Phl
production were coordinately restored in Q2-87::Tn5-1 by
complementation with either cosmid. Mobilization of one of
these cosmids into two heterologous Pseudomonas strains
conferred the ability to synthesize Phl and increased their
activity against G. graminis var. tritici, Pythium ultimum,
and Rhizoctonia solani in vitro. Subcloning and deletion
analysis of these cosmids identified a 4.8-kb region which was
necessary for Phl synthesis and antifungal activity.


117                                  NAL Call. No.: 448.3 J82
Genetic and biochemical characterization of a Pseudomonas
solanacearum gene cluster required for extracellular
polysaccharide production and for virulence.
Cook, D.; Sequeira, L.
Washington, D.C. : American Society for Microbiology; 1991
Mar. Journal of bacteriology v. 173 (5): p. 1654-1662; 1991
Mar.  Includes references.

Language:  English

Descriptors: Pseudomonas solanacearum; Plasmids; Strains;
Biochemistry; Gene expression; Genetic engineering; Genetic
transformation; Mutagenesis; Polysaccharides; Virulence

Abstract:  Infection of host plants by Pseudomonas
solanacearum results in wilting, which is thought to be due
largely to the occlusion of xylem vessels by the P.
solanacearum extracellular polysaccharide (EPS) that primarily
consists of N-acetylgalactosamine (GAlNAc). By means of Tn3
mutagenesis, we identified a 6.5-kb gene cluster that contains
five complementation units required for EPS production and
virulence in this bacterium. There was positive correlation
between the amount of EPS produced in culture and (i) in
planta growth and (ii) virulence. Based on analysis of beta-
glucuronidase-gene fusions, these genes are expressed both in
broth cultures and in planta and may be constitutive. Both
wild-type and mutant strains contained similar amounts of UDP-
GAlNAc, the predicted primary substrate for EPS synthesis.
Thus, the EPS mutants we obtained should be useful in the
analysis of steps in the assembly of the polysaccharide and
how this process is related to virulence.


118                                NAL Call. No.: 442.8 J8224
Genetic and functional analysis of the basic replicon of
pPS10, a plasmid specific for Pseudomonas isolated from
Pseudomonas syringae pathovar savastanoi.
Nieto, C.; Giraldo, R.; Fernandez-Tresguerres, E.; Diaz, R.
London : Academic Press; 1992 Jan20.
Journal of molecular biology v. 223 (2): p. 415-426; 1992
Jan20.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. savastanoi; Genetic
analysis; Nucleotide sequences; Dna; Plasmids; Dna
replication; Genes; Comparisons; Host range

Abstract:  The sequence of a 1823 base-pair region containing
the replication functions of pPS10, a narrow host-range
plasmid isolated from a strain of Pseudomonas savastanoi, is
reported. The origin of replication, oriV, or pPS10 is
contained in a 535 fragment of this sequence that can
replicate in the presence of function(s) of the plasmid, oriV
contains four of 22 base-pairs that are preceded by G + C-rich
and A + T-rich regions. A dnaA box located adjacent to repeats
of the origin is dispensable but required for efficient
replication of pPS10; A and T are equivalent bases at the 5'
end of the box. repA, the gene of a trans-acting replication
protein of 26,700 Mr has been identified by genetic and
functional analysis. repA is adjacent to the origin of
replication and is preceded by the consensus sequences of a
typical sigma(70) promoter of Escherichia coli. The RepA
protein has been identified, using the minicell system of E.
coli, as a polypeptide with an apparent molecular mass of
26,000. A minimal pPS10 replicon has been defined to a
continuous 1267 base-pair region of pPS10 that includes the
oriV and repA sequences.


119                                  NAL Call. No.: 442.8 Z34
Genetic and molecular analysis of a cluster of rpf genes
involved in positive regulation of synthesis of extracellular
enzymes and polysaccharides in Xanthomonas campestris pathover
campestris.
Tang, J.L.; Liu, Y.N.; Barber, C.E.; Dow, J.M.; Wootton, J.C.;
Daniels, M.J. Berlin, W. Ger. : Springer International; 1991
May.
M G G : Molecular and general genetics v. 226 (3): p. 409-417;
1991 May. Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. campestris; Genes;
Regulation; Protein synthesis; Cellulose; Amylases; O-
glycoside hydrolases; Proteinases; Xanthan; Carbohydrate
metabolism; Enzyme activity; Cloning; Nucleotide sequences;
Induced mutations; Insertional mutagenesis; Transposable
elements; Bacterial proteins; Restriction mapping;
Pathogenicity; Brassica campestris var. rapa; Amino acid
sequences

Abstract:  The cosmid clone, pIJ3020 containing DNA from the
plant pathogenic bacterium Xanthomonas campestris pathovar
campestris has previously been shown to complement a non-
pathogenic mutant defective in synthesis of extracellular
enzymes. The DNA cloned in pIJ3020 was analysed by mutagenesis
with Tn5 and Tn5lac and by nucleotide sequencing. The results
indicate that this region of the genome contains a cluster of
genes, mutation in any of which results in failure of the
enzymes and extracellular polysaccharide to be synthesized.
The designation rpf (regulation of pathogenicity factors) is
proposed for these genes. The nucleotide sequence of one gene
(rpfC) predicts a protein product with homology to conserved
domains of both sensor and regulator proteins of prokaryotic
two-component regulatory systems, which are usually involved
in regulating gene expression in response to environmental
stimuli.


120                                  NAL Call. No.: 448.3 J82
Genetic and transcriptional organization of the hrp cluster of
Pseudomanas syringae pv. phaseolicola.
Rahme, L.G.; Mindrinos, M.N.; Panopoulos, N.J.
Washington, D.C. : American Society for Microbiology; 1991
Jan. Journal of bacteriology v. 173 (2): p. 575-586; 1991 Jan. 
Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Pseudomonas syringae; Genes;
Pathogenicity; Genetic analysis

Abstract:  The hrp cluster of Pseudomonas syringae pv.
phaseolicola encodes functions that are essential for
pathogenicity on bean plants and for the elicitation of the
hypersensitive response on resistant plants. The cluster was
saturated with insertions of transposon Tn3-spice that served
both as a mutagen and as a sensitive reporter of the
expression of the target regions. The mutations covered a
17.5-kb segment in strain NPS3121, in which seven hrp::Tn5
insertions had been previously mapped, and regions outside
this segment. The cluster is organized into seven distinct
complementation groups (hrpL, hrpAB, hrpC, hrpD, hrpE, hrpF,
and hrpSR) on the basis of the analysis of over 100 Tn3-spice
insertions in plasmids and 43 similar insertions in the
chromosome; it spans nearly 22 kb and is chromosomally
located. The transcriptional orientation of all genes in the
cluster was established by measuring the level of ice
nucleation activity of complemented merodiploids carrying
chromosomal hrp::inaZ fusions after inoculation in Red Kidney
bean leaves. Although all seven loci were actively expressed
in Red Kidney bean leaves, none of them was substantially
expressed when the bacteria were grown in King B broth medium.
Mutations in all loci, except those in hrpc, greatly reduced
the ability of the bacteria to multiply in bean leaves.
Mutations in the hrpC locus, although preventing the bacteria
from eliciting a hypersensitive reaction on tobacco, allowed
the bacteria to produce delayed and attenuated symptoms in Red
Kidney bean leaves and to multiply to a level 10(2)- to 10(3)-
fold lower than that of the wild-type strain. This is the
first comprehensive report of the genetic and transcriptional
organization of the hrp gene cluster in a phytopathogenic
bacterium.


121                                NAL Call. No.: SB732.6.M65
Genetic evidence that extracellular polysaccharide is a
virulence factor of Pseudomonas solanacearum.
Denny, T.P.; Baek, S.R.
St. Paul, Minn. : APS Press; 1991 Mar.
Molecular plant-microbe interactions : MPMI v. 4 (2): p.
198-206; 1991 Mar. Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Pseudomonas
solanacearum; Virulence; Polysaccharides; Mutants; Strains;
Strain differences; Genetic analysis; Plasmids; Mutagenesis;
Gene expression; Phenotypes; Molecular genetics


122                                  NAL Call. No.: 448.3 AP5
Genetic iterrelatedness among clover proliferation
mycoplasmalike organisms (MLOs) and other MLOs investigated by
nucleic acid hybridization and restriction fragment length
polymorphism analyses.
Lee, I.M.; Davis, R.E.; Hiruki, C.
Washington, D.C. : American Society for Microbiology; 1991
Dec. Applied and environmental microbiology v. 57 (12): p.
3565-3569; 1991 Dec. Includes references.

Language:  English

Descriptors: Catharanthus roseus; Mycoplasma-like organisms;
Strains; Genetic analysis; Sweet potato witches' broom; Aster
yellows

Abstract:  DNA was isolated from clover proliferation (CP)
mycoplasmalike organism (MLO)-diseased periwinkle plants
(Catharanthus roseus (L.) G. Don.) and cloned into pSP6
plasmid vectors. CP MLO-specific recombinant DNA clones were
biotin labeled and used as probes in dot hybridization and
restriction fragment length polymorphism analyses to study the
genetic interrelatedness among CP MLO and other MLOs,
including potato witches'-broom (PWB) MLO. Results from dot
hybridization analyses indicated that both a Maryland strain
of aster yellows and a California strain of aster yellows are
distantly related to CP MLO. Elm yellows, paulownia witches'-
broom, peanut witches'-broom, loofah witches'-broom, and sweet
potato witches'-broom may be very distantly related, if at
all, to CP MLO. A new Jersey strain of aster yellows MLO,
tomato big bud MLO, clover phyllody MLO, beet leafhopper-
transmitted virescence MLO, and ash yellows MLO are related to
CP MLO, but PWB MLO is the most closely related. Similarity
coefficients derived from restriction fragment length
polymorphism analyses revealed that PWB and CP MLOs are
closely related strains and thus provided direct evidence of
their relatedness in contrast to reliance solely on biological
characterization.


123                                  NAL Call. No.: 464.8 P56
Genetic relatedness between two nonculturable mycoplasmalike
organisms revealed by nucleic acid hybridization and
polymerase chain reaction. Deng, S.; Hiruki, C.
St. Paul, Minn. : American Phytopathological Society; 1991
Dec. Phytopathology v. 81 (12): p. 1475-1479; 1991 Dec. 
Includes references.

Language:  English

Descriptors: Catharanthus roseus; Mycoplasma-like organisms;
Comparisons; Genetic analysis; Dna; Phyllody; Aster yellows;
Witches' brooms; Restriction fragment length polymorphism;
Genetic differences

Abstract:  Dot-blot hybridization, using nine recombinant
plasmids containing clover proliferation (CP) mycoplasmalike
organism (MLO) DNA segments, showed that the cloned CP MLO-
specific DNA probes hybridized with DNA isolated from CP MLO
and potato witches-broom (PWB) MLO-infected periwinkle plants,
but not with DNA extracted from healthy periwinkle plants nor
from those infected by MLOs associated with clover phyllody
(CPD), hydrangea virescence (HV), eastern aster yellows (EAY),
and western aster yellows (AY27). Very similar restriction
fragment length polymorphism (RFLP) of CP and PWB MLO
chromosomal DNA was observed by Southern-blot hybridization
using four different CP MLO DNA probes. Similar DNA fragments
were amplified when DNAs from CP or PWB MLO-infected plants
were used as PCR templates, whereas no DNA fragments were
amplified when DNAs from healthy CPD, HV, EAY, and AY27 MLO-
infected plants were used as polymerase chain reaction
templates. These results suggested that CP and PWB MLO
isolates are genetically related, yet distinct from CPD, HV,
EAY, and AY27 MLO isolates.


124                               NAL Call. No.: SB123.57.M64
Genetic transformation of potato to enhance nutritional value
and confer disease resistance.
Destefano-Beltran, L.; Nagpala, P.; Jaeho, K.; Dodds, J.H.;
Jaynes, J.M. Molecular approaches to crop improvement / edited
by E.S. Dennis and D.J. Llewellyn. p. 17-32; 1991. (Plant gene
research).  Includes references.

Language:  English

Descriptors: Solanum tuberosum; Nicotiana tabacum;
Agrobacterium rhizogenes; Genetic transformation; Synthetic
genes; Essential amino acids; Protein value; Potatoes;
Nucleotide sequences; Amino acid sequences; Gene transfer;
Hyalophora cecropia; Proteins; Genes; Antibacterial
properties; Antifungal properties; Genetic resistance; Fungal
diseases; Plant diseases; Plant pathogenic bacteria


125                                 NAL Call. No.: QD341.A2N8
Genetic transformation of the plant pathogens Phytophthora
capsici and Phytophthora parasitica.
Bailey, A.M.; Mena, G.L.; Herrera-Estrella, L.
Oxford : IRL Press; 1991 Aug11.
Nucleic acids research v. 19 (5): p. 4273-4278; 1991 Aug11. 
Includes references.

Language:  English

Descriptors: Phytophthora capsici; Phytophthora nicotianae
var. parasitica; Genetic transformation; Plasmids;
Protoplasts; Bioassays; Pathogenicity

Abstract:  Phytophthora capsici and P. parasitica were
transformed to hygromycin B resistance using plasmids pCM54
and pHL1, which contain the bacterial hygromycin B
phosphotransferase gene (hph) fused to promoter elements of
the Ustilago maydis heat shock hsp70 gene. Enzymes Driselase
and Novozyme 234 were used to generate protoplasts which were
then transformed following exposure to plasmid DNA and
polyethylene glycol 6000. Transformation frequencies of over
500 transformants per microgram of DNA per 1 X 10(6)
protoplasts were obtained. Plasmid pCM54 appears to be
transmitted in Phytophthora spp. as an extrachromosomal
element through replication, as shown by Southern blot
hybridization and by the loss of plasmid methylation. In
addition, transformed strains retained their capacity of
infecting Serrano pepper seedlings and Mc. Intosh apple
fruits, the host plants for P. capsici and P. parasitica,
respectively.


126                                  NAL Call. No.: 448.3 AP5
Genetic transformation system for the fungal soybean pathogen
Cercospora kikuchii.
Upchurch, R.G.; Ehrenshaft, M.; Walker, D.C.; Sanders, L.A.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Applied and environmental microbiology v. 57 (10): p.
2935-2939; 1991 Oct. Includes references.

Language:  English

Descriptors: Glycine max; Cercospora kikuchii; Mutants;
Genetic transformation; Strains; Fungicide tolerance; Benomyl;
Tubulin; Genes; Genetic markers

Abstract:  An altered beta-tubulin gene that confers
resistance to the fungicide benomyl was isolated from a
genomic library of a UV-induced mutant of Cercospora kikuchii
and used as a selectable marker for transformation. The level
of benomyl resistance conferred to the transformants was at
least 150-fold greater than the intrinsic resistance of the C.
kikuchii recipient protoplasts. In the majority of cases, the
tubulin fragment was integrated at the native beta-tubulin
locus, apparently by gene replacement or gene conversion. The
frequency of transformation ranged from 0.2 to 6 transformants
per microgram of DNA, depending on the recipient strain.
Transformation with linearized plasmid resulted in a higher
frequency, without changing the type of integration event.
Transformants were phenotypically stable after eight
consecutive transfers on medium without benomyl. This is the
first report of a genetic transformation system for a
Cercospora species.


127                                 NAL Call. No.: 442.8 AN72
Genetical variation for resistance to Alternaria solani in an
advanced population of potatoes.
Brandolini, A.
Warwick : Association of Applied Biologists; 1992 Feb.
Annals of applied biology v. 120 (2): p. 353-360; 1992 Feb. 
Includes references.

Language:  English

Descriptors: Peru; Solanum tuberosum; Alternaria solani;
Blight; Clones; Varietal susceptibility; Varietal resistance;
Genetic resistance; Genetic variation; Heritability; General
combining ability; Earliness; Crop yield


128                                  NAL Call. No.: SB731.A35
Genetics.
Shaw, D.S.
London : Academic Press; 1991.
Advances in plant pathology v. 7: p. 131-170; 1991.  In the
series analytic: Phytophthora infestans, the cause of late
blight of potato / edited by D.S. Ingram and P.H. Williams. 
Literature review.  Includes references.

Language:  English

Descriptors: Solanum tuberosum; Lycopersicon esculentum;
Phytophthora infestans; Virulence; Genes; Inheritance;
Metalaxyl; Fungicide tolerance; Genetic analysis; Meiosis;
Mitotic recombination; Dna; Molecular genetics; Restriction
fragment length polymorphism; Rna; Literature reviews


129                                   NAL Call. No.: 442.8 Z8
Genetics of leaf blight resistance in wheat.
Sinha, B.; Singh, R.M.; Singh, U.P.
Berlin, W. Ger. : Springer International; 1991.
Theoretical and applied genetics v. 82 (4): p. 399-404; 1991. 
Includes references.

Language:  English

Descriptors: Triticum aestivum; Alternaria triticina; Genetic
resistance; Blight; Epistasis; Crosses; Dominance; Plant
breeding; Recurrent selection

Abstract:  Studies on the genetics of leaf blight caused by
Alternaria triticina using generation mean analysis revealed
that additive components played a major role, but that
dominance components also contributed significantly in
controlling the variability for leaf blight resistance in
wheat crosses. Furthermore, the additive X additive type of
epistasis was predominant in the first three crosses, whereas
in the fourth cross additive X dominance (j) and dominance X
dominance (1) components of epistasis were most significant.
Because of this it may be desirable to follow a simple
recurrent selection scheme for higher tolerance, to isolate
resistant plants from the segregating populations derived from
crosses of parents of diverse origin following the pedigree
method of breeding. CPAN-1887 was very tolerant to leaf blight
in the present study and should be utilized in hybridization
programs to develop leaf-blight-resistant varieties.


130                                  NAL Call. No.: 448.3 J82
Genetics of xanthan production in Xanthomonas campestris: the
xanA and xanB genes are involved in UDP-glucose and GDP-
mannose biosynthesis. Koplin, R.; Arnold, W.; Hotte, B.;
Simon, R.; Wang, G.; Puhler, A. Washington, D.C. : American
Society for Microbiology; 1992 Jan. Journal of bacteriology v.
174 (1): p. 191-199; 1992 Jan.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris; Genes; Xanthan;
Biosynthesis; Enzymes; Guanosine diphosphate; Udp; Nucleotide
sequences; Amino acid sequences; Enzyme activity; Glucose;
Mannose

Abstract:  The nucleotide sequence of a 3.4-kb EcoRI-PstI DNA
fragment of Xanthomonas campestris pv. campestris revealed two
open reading frames, which were designated xanA and xanB. The
genes xanA and xanB encode proteins of 448 amino acids
(molecular weight of 48,919) and 466 amino acids (molecular
weight of 50,873), respectively. These genes were identified
by analyzing insertion mutants which were known to be involved
in xanthan production. Specific tests for the activities of
enzymes involved in the biosynthesis of UDP-glucose and GDP-
mannose indicated that the xanA gene product was involved in
the biosynthesis of both glucose 1-phosphate and mannose 1-
phosphate. The deduced amino acid sequence of xanB showed a
significant degree of homology (59%) to the phosphomannose
isomerase of Pseudomonas aeruginosa, a key enzyme in the
biosynthesis of alginate. Moreover, biochemical analysis and
complementation experiments with the Escherichia coli manA
fragment revealed that xanB encoded a bifunctional enzyme,
phosphomannose isomerase-GDP-mannose pyrophosphorylase.


131                                     NAL Call. No.: A00067
Germany--new programme in plant pathology.
Schonwitz, R.
Paris, France : Biofutur S.A.; 1991 Feb15.
European biotechnology newsletter (107): p. 3; 1991 Feb15.

Language:  English

Descriptors: German federal republic; Plant pathology;
Research projects; Research support; Biotechnology


132                                   NAL Call. No.: 500 N21P
Global control in Pseudomonas fluorescens mediating antibiotic
synthesis and suppression of black root rot of tobacco.
Laville, J.; Voisard, C.; Keel, C.; Maurhofer, M.; Defago, G.;
Haas, D. Washington, D.C. : The Academy; 1992 Mar01.
Proceedings of the National Academy of Sciences of the United
States of America v. 89 (5): p. 1562-1566; 1992 Mar01. 
Includes references.

Language:  English

Descriptors: Nicotiana; Root rots; Ceratocystis paradoxa;
Fungus control; Pseudomonas fluorescens; Mutations; Secondary
metabolites; Antibiotics; Hydrogen cyanide; Amino acid
sequences; Gene mapping; Genetic engineering; Nucleotide
sequences

Abstract:  Pseudomonas fluorescens CHA0 colonizes plant roots,
produces several secondary metabolites in stationary growth
phase, and suppresses a number of plant diseases, including
Thielaviopsis basicola-induced black root rot of tobacco. We
discovered that mutations in a P. fluorescens gene named gacA
(for global antibiotic and cyanide control) pleiotropically
block the production of the secondary metabolites 2,4-
diacetylphloroglucinol (Phl), HCN, and pyoluteorin. The gacA
mutants of strain CHA0 have a drastically reduced ability to
suppress black root rot under gnotobiotic conditions,
supporting the previous observations that the antibiotic Phi
and HCN individually contribute to the suppression of black
root rot. The gacA gene is directly followed by a uvrC gene.
Double gacA-uvrC mutations render P. fluorescens sensitive to
UV irradiation. The gavA-uvrC cluster is homologous to the
orf-2 (= uvrY)-uvrC operon of Escherichia coli. The gacA gene
specifies a trans-active 24-kDa protein. Sequence data
indicate that the GacA protein is a response regulator in the
FixJ/DegU family of two-component regulatory systems.
Expression of the gacA gene itself was increased in stationary
phase. We propose that GacA, perhaps activated by conditions
of restricted growth, functions as a global regulator of
secondary metabolism in P. fluorescens.


133                                   NAL Call. No.: QH426.C8
High efficiency transformation of Fusarium solani f. sp.
cucurbitae race 2 (mating population V).
Crowhurst, R.N.; Rees-George, J.; Rikkerink, E.H.A.;
Templeton, M.D. Berlin, W. Ger. : Springer International;
1992.
Current genetics v. 21 (6): p. 463-469; 1992.  Includes
references.

Language:  English

Descriptors: Fusarium solani; Genetic transformation; Cosmids;
Gene transfer; Protoplasts; Direct  DNAuptake; Drug
resistance; Hygromycin b; Plasmids; Mitosis; Reporter genes

Abstract:  A cosmid vector, suitable for library construction
and DNA transformation in filamentous fungi, has been
constructed and a reliable and highly efficient PEG-mediated
DNA transformation system for F. solani f. sp. cucurbitae,
based on resistance to hygromycin B, has been developed for
use with this vector. This transformation system yielded 10(4)
transformants per microgram of DNA when using 10(7)
protoplasts. Factors important in achieving high efficiency
included: the maintenance of an osmoticum in all
transformation steps, PEG 4000 concentration, and the ratio of
transforming vector DNA to protoplasts. Approximately 60% of
transformants stably integrated vector DNA. Molecular analysis
revealed multiple copies of the plasmid integrated into the
genome at one or more sites. The frequency of transformation
achieved will facilitate the isolation of genes from this
fungus by complementation.


134                                  NAL Call. No.: 448.3 J82
High-affinity iron uptake systems present in Erwinia
carotovora subsp. carotovora include the hydroxamate
siderophore aerobactin. Ishimaru, C.A.; Loper, J.E.
Washington, D.C. : American Society for Microbiology; 1992
May. Journal of bacteriology v. 174 (9): p. 2993-3003; 1992
May.  Includes references.

Language:  English

Descriptors: Erwinia carotovora subsp. carotovora; Strains;
Siderophores; Biosynthesis; Uptake; Genes; Pathogenicity

Abstract:  The phytopathogenic bacterium Erwinia carotovora
subsp. carotovora W3C105 produced the hydroxamate siderophore
aerobactin under iron-limiting conditions. A survey of 22
diverse strains of E. carotovora revealed that strain W3C105
alone produced aerobactin. The ferric-aerobactin receptor of
strain W3C105 was an 80-kDa protein, identified by immunoblots
of Sarkosyl-soluble proteins obtained from E. carotovora cells
grown in iron-depleted medium and probed with antiserum raised
against the 74-kDa ferric-aerobactin receptor encoded by the
pColV-K30 plasmid of Escherichia coli. Genes determining
aerobactin biosynthesis and uptake were localized to an 11.3-
kb EcoRI-HindIII chromosomal fragment of strain W3C105. A 10-
kb subclone of the fragment conferred on E. coli DH5 alpha
both aerobactin biosynthesis and uptake, determined by cloacin
DF13 sensitivity, the presence of the 80-kDa receptor protein,
and iron-independent growth of E. coli clones. The aerobactin
biosynthesis genes of E. carotovora W3C105 hybridized to those
of the pColV-K30 plasmid of E. coli, but the restriction
patterns of the aerobactin regions of E. coli and E.carotovora
differed. Although the aerobactin region of enteric bacteria
is commonly flanked by Is1-like sequences, IS1 sequences were
not detected in the genomic DNA or the cloned aerobactin
region of E. carotovora. E. coli DH5 alpha cells harboring
cloned aerobactin biosynthesis genes from E. carotovora W3C105
produced greater quantities of aerobactin and the 80-kDa
ferric-aerobactin receptor when grown in iron-limited than in
iron-replete medium. Strain W3C105 grew on an iron-limited
medium, whereas derivatives that lacked a functional
aerobactin iron acquisition system did not grow on the medium.
These results provide evidence for the occurrence and
heterogeneity of aerobactin as a high-affinity iron uptake
system of both clinical and phytopathogenic species of the
Enterobacteriaceae. Although future studies may reveal a role
for aerobactin in


135                                  NAL Call. No.: QK710.P62
High-level expression of a tobacco chitinase gene in Nicotiana
sylvestris. Susceptibility of transgenic plants to Cercospora
nicotianae infection. Neuhaus, J.M.; Ahl-Goy, P.; Hinz, U.;
Flores, S.; Meins, F. Dordrecht : Kluwer Academic Publishers;
1991 Jan.
Plant molecular biology : an international journal on
fundamental research and genetic engineering v. 16 (1): p.
141-151. ill; 1991 Jan.  Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Nicotiana sylvestris;
Cercospora nicotianae; Agrobacterium tumefaciens; Genetic
transformation; Transgenics; Chitinase; Genes; Gene
expression; Southern blotting; Northern blotting; Disease
resistance; Fungal diseases; Leaves; Sds-page; Immunoblotting;
Enzyme activity; Beta-glucanase; Ethylene; Regulation

Abstract:  Endochitinases (E.C. 3.2.14, chitinase) are
believed to be important in the biochemical defense of plants
against chitin-containing fungal pathogens. We introduced a
gene for class I (basic) tobacco chitinase regulated by
Cauliflower Mosaic Virus 35S-RNA expression signals into
Nicotiana sylvestris. The gene was expressed to give mature,
enzymatically active chitinase targeted to the intracellular
compartment of leaves. Most transformants accumulated
extremely high levels of chitinase-up to 120-fold that of non-
transformed plants in comparable tissues. Unexpectedly, some
transformants exhibited chitinase levels lower than in non-
transformed plants suggesting that the transgene inhibited
expression of the homologous host gene. Progeny tests indicate
this effect is not permanent. High levels of chitinase in
transformants did not substantially increase resistance to the
chitin-containing fungus Cercospora nicotiana, which causes
Frog Eye disease. Therefore class I chitinase does not appear
to be the limiting factor in the defense reaction to this
pathogen.


136                                  NAL Call. No.: 448.3 AP5
Homologous streptomycin resistance gene present among diverse
gram-negative bacteria in New York state apple orchards.
Norelli, J.L.; Burr, T.J.; Lo Cicero, A.M.; Gilbert, M.T.;
Katz, B.H. Washington, D.C. : American Society for
Microbiology; 1991 Feb. Applied and environmental microbiology
v. 57 (2): p. 486-491. ill; 1991 Feb. Includes references.

Language:  English

Descriptors: New York; Malus pumila; Pseudomonas syringae pv.
papulans; Streptomycin; Pesticide resistance; Genes; Dna
probes; Dna hybridization; Plasmids; Gram negative bacteria

Abstract:  The streptomycin resistance gene of Pseudomonas
syringae pv. papulans Psp36 was cloned into Escherichia coli
and used to develop a 500-bp DNA probe that is specific for
streptomycin resistance in P. syringae pv. papulans. The probe
is a portion of a 1-kb region shared by three different DNA
clones of the resistance gene. In Southern hybridizations, the
probe hybridized only with DNA isolated from streptomycin-
resistant strains of P. syringae pv. papulans and not with the
DNA of streptomycin-sensitive strains. Transposon insertions
within the region of DNA shared by the three clones resulted
in loss of resistance to streptomycin. Colony hybridization of
bacteria isolated from apple leaves and orchard soil indicated
that 39% of 398 streptomycin-resistant bacteria contained DNA
that hybridized to the probe. These included all strains of P.
syringae pv. papulans and some other fluorescent pseudomonads
and nonfluorescent gram-negative bacteria, but none of the
gram-positive bacteria. The same-size restriction fragments
hybridized to the probe in P. syringae pv. papulans.
Restriction fragment length polymorphism of this region was
occasionally observed in strains of other taxonomic groups of
bacteria. In bacteria other than P. syringae pv. papulans, the
streptomycin resistance probe hybridized to different-sized
plasmids and no relationship between plasmid size and
taxonomic group or between plasmid size and orchard type, soil
association, or leaf association could be detected.


137                                 NAL Call. No.: QH442.A1G4
Identification and characterization of the ribosomal RNA-
encoding genes in Clavibacter xyli subsp. cynodontis.
Sathyamoorthy, M.; Alcorn, S.C.; Lohnas, G.L.; Anderson, J.J.;
Uratani, B.B. Amsterdam : Elsevier Science Publishers; 1991.
Gene v. 108 (1): p. 47-53; 1991.  Includes references.

Language:  English

Descriptors: Clavibacter xyli; Ribosomal  RNA; Genes;
Ribosomal  DNA; Nucleotide sequences; Restriction mapping;
Gene mapping; Endophytes; Cynodon dactylon

Abstract:  Clavibacter xyli subsp. cynodontis (Cxc) is a
xylem-inhabiting bacterial endophyte of Bermudagrass. This
organism is classified with Gram-positive, high G + C content,
coryneform-actinomycete bacteria. Southern-blot analysis
showed that Cxc, contains only one copy of the ribosomal RNA-
encoding genes (rRNA). A clone containing the rRNA genes was
isolated from a genomic library of Cxc DNA cloned in the
lambda EMBL3 vector. The gene cluster was partially sequenced,
revealing the gene order 5'-16S-23S-5S-3', similar to that
found in other prokaryotes. Low-resolution S1 mapping
suggested multiple transcription start points of the rRNA
operon.


138                                   NAL Call. No.: 500 N21P
Identification of a fungal cutinase promoter that is inducible
by a plant signal via a phosphorylated trans-acting factor.
Bajar, A.; Krishna Podila, G.; Kolattukudy, P.E.
Washington, D.C. : The Academy; 1991 Sep15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (18): p. 8208-8212; 1991 Sep15. 
Includes references.

Language:  English

Descriptors: Fusarium solani f.sp. pisi; Chloramphenicol
acetyltransferase; Cutin; Enzyme activity; Enzyme inhibitors;
Gene expression; Growth promoters; Kinases; Phosphorylation;
Transcription

Abstract:  Plant cutin monomers trigger, and glucose
suppresses, the expression of the cutinase gene of pathogenic
fungi. To identify the cutinase promoter region responsible
for induction by the unique plant components, a promoter
analysis was done with transformants. Plasmids were
constructed that contained (i) the 5' flanking region of the
cutinase gene or its deletion mutants from Fusarium solani
pisi fused with a chloramphenicol acetyltransferase (CAT)
reporter gene and (ii) a constitutive promoter fused with a
hygromycin phosphotransferase gene. Hygromycin-resistant
transformants of F. solani pisi generated by electroporation
were assayed for CAT activity inducible by cutin hydrolysate
and for glucose repression of this induction. CAT was induced
in a glucose-repressible manner when fused with a 360-base-
pair (bp), or longer, segment of the 5' flanking region of the
cutinase gene, and deletion of the next 135 bp abolished this
induction. Gel retardation assays showed that a protein(s) in
nuclear extract from the fungus bound to the 5' flanking
region of cutinase gene, and this binding was also abolished
when the same 135-bp segment was deleted. These results show
that the -225 to -360 segment of the cutinase gene contains a
cis-acting regulatory element that binds trans-acting
factor(s) in the nuclei. Treatment of the nuclear extract with
immobilized phosphatase abolished binding to the promoter,
suggesting that binding required a phosphorylated form of the
protein. With isolated nuclei, phosphorylation of a protein
occurred only in the presence of both cutin monomer and the
fungal protein factor. The presence of protein kinase
inhibitor H7 during the preincubation of nuclei with the
monomer and protein factor inhibited cutinase gene
transcription. These results suggest that cutin monomer causes
phosphorylation of a transcription factor that binds to the
-225 to -360 segment of the cutinase gene and enhances
transcription of this gene.


139                                  NAL Call. No.: 464.8 P56
Identification of a plasmid DNA probe for detection of strains
of Erwinia herbicola pathogenic on Gypsophila paniculata.
Manulis, S.; Gafni, Y.; Clark, E.; Zutra, D.; Ophir, Y.;
Barash, I. St. Paul, Minn. : American Phytopathological
Society; 1991 Jan. Phytopathology v. 81 (1): p. 54-57. ill;
1991 Jan.  Includes references.

Language:  English

Descriptors: Gypsophila paniculata; Erwinia herbicola;
Strains; Pathogenicity; Serotypes; Detection; Dna probes;
Plasmids; Immunodiagnosis; Iaa; Biosynthesis

Abstract:  Pathogenic strains of Erwinia herbicola incite
crown and root galls in Gypsophila paniculata. Two serotypic
groups were detected in the population of strains isolated
from Gypsophila, each of which was composed of pathogens and
nonpathogens. An additional isolate of pathogenic E herbicola
did not react with serotype I or II. Galls caused by
pathogenic serotype I strains varied in morphological
appearance from galls of other pathogenic strains. All strains
secreted indoleacetic acid (IAA) in culture. No correlation
was observed between gall size and the amount of IAA produced
in vitro. All strains also contained one to four plasmids with
sizes ranging between 10 and 100 MDa. A 7.5-kilobase (kb) DNA
fragment was subcloned from a library constructed from plasmid
DNA of a pathogenic strain. This DNA fragment cross-hybridized
with the sequences encoding the IAA biosynthetic pathway in
Pseudomonas savastanoi. The cloned 7.5-kb fragment was used to
distinguish among pathogenic and nonpathogenic strains of each
serotypic group by blot hybridization experiments. The probe
hybridized to 78-MDa plasmids present in pathogenic strains of
serotypes I and Ill and to 100-MDa plasmids present in
pathogenic strains of serotype II. The relationship between
IAA production and the specificity of the probe is discussed.


140                                NAL Call. No.: SB732.6.M65
Identification of pathogenicity determinants of Erwinia
carotovora subsp. carotovora by transposon mutagenesis.
Pirhonen, M.; Saarilahti, H.; Karlsson, M.B.; Palva, E.T. St.
Paul, Minn. : APS Press; 1991 May.
Molecular plant-microbe interactions : MPMI v. 4 (3): p.
276-283; 1991 May. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Solanum tuberosum; Erwinia
carotovora subsp. carotovora; Virulence; Induced mutations;
Mutants; Mutagenesis; Phenotypes; Host parasite relationships;
Transposable elements; Transduction; Screening; Assays;
Molecular genetics


141                                 NAL Call. No.: QK725.P532
Identification of Pseudomonas syringae pathogens of
Arabidopsis and a bacterial locus determining avirulence on
both Arabidopsis and soybean. Whalen, M.C.; Innes, R.W.; Bent,
A.F.; Staskawicz, B.J.
Rockville, Md. : American Society of Plant Physiologists; 1991
Jan. The Plant cell v. 3 (1): p. 49-59. ill; 1991 Jan. 
Includes references.

Language:  English

Descriptors: Arabidopsis thaliana; Glycine max; Brassica;
Lycopersicon esculentum; Pseudomonas syringae pv. maculicola;
Pseudomonas syringae pv. tomato; Pseudomonas syringae pv.
glycinea; Loci; Genetic resistance; Virulence; Susceptibility;
Disease resistance; Ecotypes; Dna libraries; Cosmids; Leaves;
Infections; Ultrastructure

Abstract:  To develop a model system for molecular genetic
analysis of plant-pathogen interactions, we studied the
interaction between Arabidopsis thaliana and the bacterial
pathogen Pseudomonas syringae pv tomato (Pst). Pst strains
were found to be virulent or avirulent on specific Arabidopsis
ecotypes, and single ecotypes were resistant to some Pst
strains and susceptible to others. In many plant-pathogen
interactions, disease resistance is controlled by the
simultaneous presence of single plant resistance genes and
single pathogen avirulence genes. Therefore, we tested whether
avirulence genes in Pst controlled induction of resistance in
Arabidopsis. Cosmids that determine avirulence were isolated
from Pst genomic libraries, and the Pst avirulence locus
avrRpt2 was defined. This allowed us to construct pathogens
that differed only by the presence or absence of a single
putative avirulence gene. We found that Arabidopsis ecotype
Col-0 was susceptible to Pst strain DC3000 but resistant to
the same strain carrying avrRpt2, suggesting that a single
locus in Col-0 determines resistance. As a first step toward
genetically mapping the postulated resistance locus, an
ecotype susceptible to infection by DC3000 carrying avrRpt2
was identified. The avrRpt2 locus from Pst was also moved into
virulent strains of the soybean pathogen P. syringae pv
glycinea to test whether this locus could determine avirulence
on soybean. The resulting strains induced a resistant response
in a cultivar-specific manner, suggesting that similar
resistance mechanisms may function in Arabidopsis and soybean.


142                                 NAL Call. No.: 448.3 J823
Identification of the exo loci required for exopolysaccharide
synthesis in Agrobacterium radiobacter NCIB 11883.
Aird, E.L.H.; Brightwell, G.; Jones, M.A.; Johnston, A.W.B.
Reading : Society for General Microbiology; 1991 Oct.
The Journal of general microbiology v. 137 (pt.10): p.
2287-2297; 1991 Oct. Includes references.

Language:  English

Descriptors: Agrobacterium radiobacter; Mutants;
Polysaccharides; Biosynthesis; Rhizobium meliloti; Genes;
Loci; Clones; Cosmids; Plasmids; Dna; Gene transfer;
Recombination

Abstract:  We initiated a genetic analysis of Agrobacterium
radiobacter NCIB 11883 with particular reference to the (exo)
genes required for exopolysaccharide synthesis. Following
mutagenesis with nitrosoguanidine, several exo mutant strains
were isolated and several of the mutations were corrected by
DNA cloned in a newly constructed cosmid library. Analysis of
various complementing cosmids by genetic and physical criteria
indicated that exo loci were quite widely dispersed in the
bacterial genome. Certain exo mutations were corrected by
different cosmids that shared no homologous DNA; possible
explanations for this are presented. Using phoA fusions, it
was shown that some exo genes were, or were closely linked to,
genes that specified polypeptides associated with the
bacterial cell surface. By introducing the cloned exo genes of
Rhizobium meliloti it was found that only one out of thirty
exo mutants of A. radiobacter was corrected by a defined exo
locus of the former species; further analysis indicated that
this particular exo gene corresponded to exoB of R. meliloti.
Finally, it was found that several A. radiobacter exo mutants
were non-mucoid on media with dicarboxylic acids as sole
carbon source but appeared to be wild-type when sugars were
the source of carbon.


143                                  NAL Call. No.: 442.8 Z34
Identification of two fructose transport and phosphorylation
pathways in Xanthomonas campestris pv. campestris.
Crecy-Lagard, V. de; Lejeune, P.; Bouvet, O.M.M.; Danchin, A.
Berlin, W. Ger. : Springer International; 1991 Jul.
M G G : Molecular and general genetics v. 227 (3): p. 465-472;
1991 Jul. Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. campestris; Fructose;
Active transport; Phosphotransferases; Insertional
mutagenesis; Transposable elements; Cloning; Nucleotide
sequences; Amino acid sequences; Restriction mapping;
Phosphorylation; Enzyme activity; Induced mutations; Mutants;
Fructokinase; Carbohydrate metabolism; Mannose; Sucrose;
Mannitol

Abstract:  Fructose was shown to be phosphorylated by a
specific phosphoenolpyruvate-dependent phosphotransferase
system (PTS) in Xanthomonas campestris pv. campestris.
Transposon mutagenesis of X. campestris was performed and two
mutants affected in growth on fructose were isolated. Both
mutants were deficient in PTS activity. Comparison of the rate
of uptake and phosphorylation of fructose in the wild-type and
in the mutant strains revealed the presence of a second
fructose permeation and phosphorylation pathway in this
bacterium: an unidentified permease coupled to an ATP-
dependent fructokinase. One of the two mutants was also
deficient in fructokinase activity. Chromosomal DNA fragments
containing the regions flanking the transposon insertion site
were cloned from both mutant strains. Their physical study
revealed that the insertion sites were separated by 1.4 kb,
allowing the reconstruction of a wild-type DNA fragment which
complemented one of the two mutants. The region flanking the
transposon insertion site was sequenced in one of the mutants,
showing that the transposon had interrupted the gene encoding
the fructose EII. The mutant strains also failed to utilize
mannose, sucrose and mannitol, suggesting the existence of a
branch point between the metabolism of fructose and of these
latter carbohydrates.


144                                   NAL Call. No.: 470 C16C
An immunofluorescent cytochemical technique applying
micromanipulation to detect microtubules in plant tissues
inoculated with fungal spores. Kobayashi, I.; Kobayashi, Y.;
Yamaoka, N.; Kunoh, H.
Ottawa, Ont. : National Research Council of Canada; 1991 Dec.
Canadian journal of botany; Journal canadien de botanique v.
69 (12): p. 2634-2636; 1991 Dec.  Includes references.

Language:  English

Descriptors: Hordeum vulgare; Coleoptiles; Erysiphe pisi;
Plant pathogenic fungi; Infectivity; Mycelium; Plant anatomy


145                                  NAL Call. No.: QH301.N32
In vitro disease resistance for expression of somaclonal
variation in Larix. Diner, A.M.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 63-65;
1991.  In the series analytic: Woody plant biotechnology /
edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Includes references.

Language:  English

Descriptors: Larix decidua; Genotypes; Disease resistance;
Cankers; Gremmeniella; Organogenesis; Somaclonal variation


146                                  NAL Call. No.: QK710.P55
Induction of crown galls by Agrobacterium tumefaciens (strain
C58) reverses assimilate translocation and accumulation in
Kalanchoe daigremontiana. Malsy, S.; Bel, A.J.E. van; Kluge,
M.; Hartung, W.; Ullrich, C.I. Oxford : Blackwell Scientific
Publications; 1992 Jun.
Plant, cell and environment v. 15 (5): p. 519-529; 1992 Jun. 
Includes references.

Language:  English

Descriptors: Kalanchoe daigremontiana; Nicotiana tabacum;
Agrobacterium tumefaciens; Crown gall; Membrane potential;
Plasma membranes; Iaa; Abscisic acid; Source sink relations;
Photosynthates; Nutrient transport; Zeatin; Phloem; Sieve
plates; Amino acids; Cell suspensions; Genetic transformation;
Genes; Dna; Sugars; Nopaline; Phloem loading; Phloem companion
cells


147                                  NAL Call. No.: 64.8 C883
Inheritance of resistance to race 4 of downy mildew derived
from interspecific crosses in sunflower.
Miller, J.F.; Gulya, T.J.
Madison, Wis. : Crop Science Society of America; 1991 Jan.
Crop science v. 31 (1): p. 40-43; 1991 Jan.  Includes
references.

Language:  English

Descriptors: Helianthus annuus; Helianthus; Helianthus
argophyllus; Plasmopara halstedii; Inheritance; Genetic
resistance; Races; Genes; Dominance; Segregation; Mildews;
Wild plants; Lines; Crosses

Abstract:  Race 4 of downy mildew, incited by Plasmopara
halstedii (Farl.) Berl. & de Toni was first reported in
sunflower (Helianthus annuus L.) in the USA during 1985.
Resistance to this race was found in lines derived from
interspecific crosses of cultivated sunflower with three
species of wild sunflower. The objectives of this
investigation were to determine the genetic control of
resistance found in the interspecific crosses and to determine
if this resistance was conditioned by the same or different
genes. Ratios tested utilizing a chi-square analysis for
goodness of fit for F2 and BC1F1 generations indicated that
resistance to Race 4 was conditioned by a single, dominant
gene in all sources. Four lines (HA 335, HA 336, Charata R4,
and Wild Ornamental) were determined to have the same
resistance gene Pl6. HA 335 and HA 336 were derived from wild
H. annuus 423 and H. annuus 432, respectively. The resistance
gene in HA 339, derived from H. praecox Engelm. & Gray ssp.
runyonii proved to be different and was designated Pl7. The
resistance gene in RHA 340, distinct from Pl6 and Pl7 and
derived from H. argophyllus Torrey & Gray, was designated Pl3.
Using divergent resistance genes in sunflower commercial
hybrids should decrease genetic vulnerability to changes in
pathogenicity of downy mildew. However, additional wild
species of sunflower should be collected and tested to
identify new sources of resistance to downy mildew.


148                                   NAL Call. No.: 500 N21P
Integration and expression of a rabbit liver cytochrome P-450
gene in transgenic Nicotiana tabacum.
Saito, K.; Noji, M.; Ohmori, S.; Imai, Y.; Murakoshi, I.
Washington, D.C. : The Academy; 1991 Aug15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (16): p. 7041-7045; 1991 Aug15. 
Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Cytochromes; Gene expression;
Genetic transformation; Metabolism; Nucleotide sequences;
Phenotypes; Plasmids; Senescence; Transgenics; Agrobacterium
tumefaciens

Abstract:  Cytochrome P-450 is involved in the oxidative
metabolism of a broad range of substrates. We have made a
chimeric construct, pSN002, containing the cDNA for rabbit
liver cytochrome P-450 (IIC14) under the control of the TR2'
promoter for mannopine synthase in the Agrobacterium Ti
plasmid. Nicotiana tabacum was transformed with Agrobacterium
tumefaciens harboring a cointegrated plasmid pSN002::pGV2260.
The presence of mRNA and of the translated protein from the
chimeric cytochrome P-450 gene in transgenic plants was
confirmed by RNA blot hybridization and by Western blot and
immunohistochemical analyses, respectively. The transformants
in which the foreign cytochrome P-450 protein is expressed
show marked phenotypic changes, notably a tendency rapidly to
senesce. We detected 2-propenylpyrrolidine, a degradative
metabolite of nicotine alkaloids, in transgenic tobacco
showing this pronounced phenotypic change. Such metabolism is
likely to be due to the effect of senescence and not directly
to the presence of the cytochrome P-450.


149                                 NAL Call. No.: 448.3 J823
Isolation and characterization of behavioural mutants and
genes of Agrobacterium tumefaciens.
Shaw, C.H.; Loake, G.J.; Brown, A.P.; Garrett, C.S.; Deakin,
W.; Alton, G.; Hall, M.; Jones, S.A.; O'Leary, M.; Primavesi,
L.
Reading : Society for General Microbiology; 1991 Aug.
The Journal of general microbiology v. 137 (pt.8): p.
1939-1953; 1991 Aug. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Mutants; Genes;
Cosmids; Chemotaxis; Motility; Flagella; Behavior

Abstract:  Agrobacterium tumefaciens exhibits an unusual
flagellation pattern in the electron microscope. The typical
pattern is of two flagella in a polar or sub-polar tuft at one
pole only, plus one or two lateral flagella on each side.
Twenty independent behavioural mutants were isolated, after
Tn5 mutagenesis, and divided into several classes. Fourteen
non-motile mutants were differentiable into non-flagellate and
flagellate subclasses, one non-chemotactic mutant appeared to
have a defect in the intracellular signalling pathway, and one
other mutant displayed an unusual pattern of polar cell
pairing. Four mutants with impaired swarming ability were also
isolated. Root colonization ability was impaired in the non-
motile mutant for which this property was tested. From all but
three of the mutants, the Tn5 insertion sites, including
flanking sequences, have been cloned and used as probes to
isolate a set of seven cosmids from a wild-type A. tumefaciens
library. No hybridization to Escherichia coli or Pseudomonas
DNA was detected for the A. tumefaciens mutant flanking
sequences, but varying degrees of similarity to Rhizobium
meliloti behavioural genes were detected. By complementation
of A. tumefaciens behavioural mutants and hybridization of
mutant flanking sequences, one cosmid insert was shown to
contain at least nine behavioural loci, and another, linked to
it on the chromosome, at least three. This suggests that, as
in other organisms, behavioural genes are clustered in the A.
tumefaciens genome.


150                                 NAL Call. No.: 464.8 P692
The isolation and characterization of polyclonal and
monoclonal antibodies to anastomosis group 8 of Rhizoctonia
solani.
Matthew, J.S.; Brooker, J.D.
Oxford : Blackwell Scientific Publications; 1991 Mar.
Plant pathology v. 40 (1): p. 67-77. ill; 1991 Mar.  Includes
references.

Language:  English

Descriptors: Rhizoctonia solani; Anastomosis groups;
Monoclonal antibodies; Immunodiagnosis; Serological
relationships; Identification; Cross reaction;
Characterization

Abstract:  Polyclonal and monoclonal antibodies were raised
against secreted proteins from an anastomosis group 8 isolate
of Rhizoctonia and tested for reactivity to field isolates
from anastomosis groups 2-1, 3, 4 and 8, Polyclonal antibodies
raised against total secreted proteins cross-reacted in
immunoblotting experiments with all R. solani isolates
However, immunoreactive proteins specific to Ag-8 isolates
were evident. Monoclonal antibodies to secreted proteins were
raised which reacted with fewer proteins and showed a greater
degree of specificity for AG-8 isolates. Two monoclonals were
selected for further study. One, an IgM monoclonal antibody,
reacted with all R. solani isolates, recognizing a 40-kDa
protein specific to AG-8 isolates and proteins of lower
molecular weight in isolates from other anastomosis groups.
The other, an IgG monoclonal antibody, was more specific,
reacting with 38-, 40-and 55-kDa proteins from AG-8 isolates
and cross-reacting, with few isolates from other anastomosis
groups. Preliminary results on the induction of antigens
recognized by the monoclonal antibodies are presented. The
monoclonal antibodies characterized here are useful for the
identification of isolates of R. solani and may also be used
as probes to clarify the relationships between anastomosis
groups.


151                                NAL Call. No.: SB732.6.M65
Isolation and gene disruption of the Tox5 gene encoding
trichodiene synthase in Gibberella pulicaris.
Hohn, T.M.; Desjardins, A.E.
St. Paul, Minn. : APS Press; 1992 May.
Molecular plant-microbe interactions : MPMI v. 5 (3): p.
249-256; 1992 May. Includes references.

Language:  English

Descriptors: Solanum tuberosum; Gibberella pulicaris; Genes;
Trichothecenes; Biosynthesis; Ligases; Inhibition; Genetic
analysis; Plant pathogenic fungi; Genetic transformation;
Plasmids; Mutants; Strains; Phenotypes; Nucleotide sequences;
Amino acid sequences; Comparisons; Fusarium sporotrichioides


152                                   NAL Call. No.: QH426.C8
Isolation, characterization and sequence of a gene conferring
resistance to the systemic fungicide carboxin from the maize
smut pathogen, Ustilago maydis. Keon, J.P.R.; White, G.A.;
Hargreaves, J.A.
Berlin, W. Ger. : Springer International; 1991.
Current genetics v. 19 (6): p. 475-481; 1991.  Includes
references.

Language:  English

Descriptors: Ustilago zeae; Zea mays; Genetic code; Carboxin;
Resistance; Nucleotide sequences; Amino acid sequences; Plant
pathogenic fungi; Genetic transformation; Genetic markers;
Mutants; Gene expression; Plasmids; Gene mapping

Abstract:  A gene which confers resistance to the systemic
fungicide carboxin (Cbx) has been isolated from the maize
pathogen, Ustilago maydis, by transferring a plasmid gene
library from a Cbx-resistant mutant strain into a sensitive
strain and selecting for expression of the resistance gene.
Five plasmids, rescued from transformants which exhibited
enhanced resistance to Cbx, were shown to have DNA inserts
with common restriction enzyme fragments. All the plasmids
transformed a sensitive U. maydis strain to Cbx resistance.
The gene (Cbx(r)), sub-cloned on a 3.2 kb EcoR1-HindIII
fragment, transformed U. maydis to Cbx resistance at
frequencies similar to those obtained with the bacterial
Hygromycin B resistance (HygB(r)) gene. The sequence of the
Cbx(r) gene showed a high degree of homology to succinate
dehydrogenase (EC 1.3.99.1) iron-sulphur subunit genes from
other organisms.


153                                 NAL Call. No.: 448.3 J823
Isolation of a benomyl-resistant allele of the beta-tubulin
gene from Septoria nodorum and its use as a dominant
selectable marker.
Cooley, R.N.; Gorcom, R.F.M. van; Hondel, C.A.M.J.J. van den;
Caten, C.E. Reading : Society for General Microbiology; 1991
Sep.
The Journal of general microbiology v. 137 (pt.9): p.
2085-2091; 1991 Sep. Includes references.

Language:  English

Descriptors: Leptosphaeria nodorum; Mutants; Tubulin; Genes;
Benomyl; Fungicide tolerance; Pathogenesis; Marker genes;
Genetic transformation; Cosmids; Clones

Abstract:  We have developed a homologous transformation
system for the wheat-pathogenic fungus Septoria nodorum based
on a benomyl-(MBC-) resistant allele of the beta-tubulin gene.
The beta-tubulin gene was isolated by heterologous
hybridization from a cosmid library prepared from an MBC-
resistant mutant. Cosmids carrying the gene conferred MBC
resistance when introduced into a sensitive strain,
demonstrating that resistance to MBC fungicides in S. nodorum
may be determined by the beta-tubulin gene. This MBC resistant
allele of the P-tubulin gene (tuba R) was subcloned into pUC18
and used as a dominant selectable marker for transformation of
wild-type sensitive strains. Transformants arose at
frequencies of approximately 5 per pg of DNA, were integrative
in nature and were mitotically stable. Some transformants
showed a marked reduction in vigour, both in the presence and
absence of MBC; this is thought to arise from overproduction
of beta-tubulin. The S. nodorum tubA R gene also conferred MBC
resistance on the related species Leptosphaeria maculans, a
pathogen of Brassica, following its introduction by
cotransformation. Probing digested SL nodorum DNA with tubA R
at low stringency revealed only a single P-tubulin gene. We
anticipate that tubA R will prove a useful tool for the
investigation of the pathogenicity of S. nodorum and other
fungi.


154                                NAL Call. No.: SB732.6.M65
Isolation of a gene cluster from Xanthomonas campestris pv.
vesicatoria that determines pathogenicity and the
hypersensitive response on pepper and tomato. Bonas, U.;
Schulte, R.; Fenselau, S.; Minsavage, G.V.; Staskawicz, B.J.;
Stall, R.E.
St. Paul, Minn. : APS Press; 1991 Jan.
Molecular plant-microbe interactions : MPMI v. 4 (1): p.
81-88; 1991 Jan. Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Capsicum annuum; Disease
resistance; Xanthomonas campestris pv. vesicatoria;
Pathogenicity; Genetic analysis; Insertional mutagenesis;
Genes; Complementation; Pathotypes; Comparisons; Xanthomonas
campestris


155                                  NAL Call. No.: 448.3 J82
The lemA gene required for pathogenicity of Pseudomonas
syringae pv. syringae on bean is a member of a family of two-
component regulators. Hrabak, E.M.; Willis, D.K.
Washington, D.C. : American Society for Microbiology; 1992
May. Journal of bacteriology v. 174 (9): p. 3011-3020; 1992
May.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. syringae; Pathogenicity;
Genes; Nucleotide sequences; Amino acid sequences; Phaseolus
vulgaris

Abstract:  The lemA gene of the plant pathogen Pseudomonas
syringae pv. syringae is required for disease lesion formation
on bean plants. Cosmid clones that complemented a lemA mutant
in trans were isolated previously. The lemA gene was localized
by subcloning and transposon mutagenesis. The lemA region and
flanking DNA were sequenced, and an open reading frame of 2.7
kb was identified. The nucleotide and predicted amino acid
sequences of the lemA gene showed sequence similarity to a
family of prokaryotic two-component regulatory proteins.
Unlike most of the previously described two-component systems,
the lemA gene product contained homology to both components in
one protein. Mutations introduced upstream and downstream of
the lemA gene failed to locate a gene for a second protein
component but identified the putative cysM gene of P. syringae
pv. syringae. The cysM gene was located upstream of the lemA
gene and was divergently transcribed. The lemA gene product
was expressed at low levels in P. syringae pv. syringae and
appeared to be positively auto-regulated.


156                                NAL Call. No.: SB732.6.M65
Limited host range Ti plasmids: recent origin from wide host
range Ti plasmids and involvement of a novel IS element,
IS868.
Paulus, F.; Canaday, J.; Otten, L.
St. Paul, Minn. : APS Press; 1991 Mar.
Molecular plant-microbe interactions : MPMI v. 4 (2): p.
190-197; 1991 Mar. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Biotypes; Strains;
Strain differences; Tumors; Plasmids; Host range; Genetic
analysis; Nucleotide sequences; Amino acid sequences;
Insertional mutagenesis; Comparisons; Pseudomonas syringae pv.
savastanoi; Pathogenicity


157                                   NAL Call. No.: QH426.C8
Linear DNA plasmids of the perennial ryegrass choke pathogen,
Epichloe typhina (Clavicipitaceae).
Mogen, K.L.; Siegel, M.R.; Schardl, C.L.
Berlin, W. Ger. : Springer International; 1991.
Current genetics v. 20 (6): p. 519-526; 1991.  Includes
references.

Language:  English

Descriptors: Acremonium coenophialum; Acremonium; Claviceps
purpurea; Clavicipitales; Mitochondrial  DNA; Dna; Plasmids;
Restriction mapping; Nucleotide sequences

Abstract:  Epichloe typhina is a clavicipitaceous ascomycete
which systemically infects grasses, causes choke disease of
host inflorescences, and is related to a group of mutualistic
grass endophytes. Three plasmids of 7.5, 2.1 and 2.0 kilobase
pairs were found in mitochondrial DNA preparations of an E.
typhina isolate from perennial ryegrass (Lolium perenne).
Results of nuclease digestion indicated that the plasmids,
designated Et7.5L, Et2.1L, and ET2.0L, were linear, double-
stranded DNAs with protein linked to their 5'-ends (plDNA).
The plasmids shared little or no homology with each other, and
were not integrated into the mitochondrial or nuclear genomes.
No homologous plasmids were detected in isolates of E. typhina
from other grass hosts, anamorphic endophytes, or other
Clavicipitaceae. However, other plasmids were present in
Balansia obtecta and Claviceps purpurea. A partial sequence of
one of the E. typhina plasmids, ET2.0L, indicated an open
reading frame when UGA was assumed to encode tryptophan. The
inferred amino acid sequence had 24% identity over 258 amino
acids in two regions of the reverse transcriptase encoded by
the circular Mauriceville and Varkud plasmids of Neurospora
spp. The homologies included six segments conserved in RNA
template-dependent DNA or RNA polymerases.


158                                   NAL Call. No.: QH426.C8
Linear, non-mitochondrial plasmids of Alternaria alternata.
Shepherd, H.S.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (2): p. 169-172; 1992.  Includes
references.

Language:  English

Descriptors: Alternaria alternata; Plasmids; Mitochondria

Abstract:  Three plasmids, with sizes of 7.0 kbp, 6.8 kbp, and
5.0 kbp and designated pAal-1, pAal-2 and pAal-3 respectively,
have been found in a tentoxin-producing isolate of Alternaria
alternata. Exonuclease digestions show these plasmids to be
linear with blocked 5' ends. Plasmid pAal-1 does not hybridize
to nuclear DNA, mitochondrial DNA, or double-stranded RNA from
a mycovirus found in the isolate, but does hybridize weakly to
a series of linear DNAs which are not visible on gels and may
include pAal-2 and pAal-3. Cellular fractionation shows that,
unlike other linear fungal plasmids, these plasmids are not
localized in the mitochondria. Plasmids have not been found in
other tentoxin-producing isolates and there is no evidence
that these plasmids have any effect on the production of
tentoxin.


159                                  NAL Call. No.: 442.8 Z34
Localization and orientation of the VirD4 protein of
Agrobacterium tumefaciens in the cell membrane.
Okamoto, S.; Toyoda-Yamamoto, A.; Ito, K.; Takebe, I.;
Machida, Y. Berlin, W. Ger. : Springer International; 1991
Aug.
M G G : Molecular and general genetics v. 228 (1/2): p. 24-32;
1991 Aug. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Bacterial proteins;
Spatial distribution; Cell membranes; Genes; Crown gall;
Genetic engineering; Alkaline phosphatase; Marker genes

Abstract:  The virD4 gene of Agrobacterium tumefaciens is
essential for the formation of crown galls. Analysis of the
nucleotide sequence of virD4 has suggested that the N-terminal
region of the encoded protein acts as a signal peptide for the
transport of the VirD4 protein to the cell membrane of
Agrobacterium. We have examined the localization and
orientation of this protein in the cell membrane. When the
nucleotides encoding the first 30 to 41 amino acids from the
N-terminus of the VirD4 protein were fused to the gene for
alkaline phosphatase from which the signal sequence had been
removed, alkaline phosphatase activity was detectable under
appropriate conditions. Immunoblotting with VirD4-specific
antiserum indicated that the VirD4 protein could be recovered
exclusively from the membrane fraction of Agrobacterium cells.
Moreover, when the membrane fraction was separated into inner
and outer membrane fractions by sucrose density-gradient
centrifugation, VirD4 protein was detected in the inner-
membrane fraction and in fractions that sedimented between the
inner and outer membrane fractions. By contrast, the
VirD4'/'alkaline phosphatase fusion protein with the N-
terminal sequence from VirD4 was detected only in the inner
membrane fraction. Treatment of spheroplasts of Agrobacterium
cells with proteinase K resulted in digestion of the VirD4
protein. These results indicate that the VirD4 protein is
transported to the bacterial membrane and anchored on the
inner membrane by its N-terminal region. In addition, the C-
terminal portion of the VirD4 protein probably protrudes into
the periplasmic space, perhaps in association with some
unidentified cellular factor(s).


160                                  NAL Call. No.: SB599.P45
Localization of carbohydrate antigens in the walls of
Phytophthora megasperma f.sp. glycinea by monoclonal
antibodies.
Wycoff, K.L.; Ayers, A.R.
London : Academic Press; 1991 Aug.
Physiological and molecular plant pathology v. 39 (2): p.
95-109; 1991 Aug. Includes references.

Language:  English

Descriptors: Glycine max; Host parasite relationships;
Phytophthora megasperma; Cell walls; Hyphae; Cell wall
components; Beta-glucan; Fungal antigens; Monoclonal
antibodies; Immunological techniques; Immunofluorescence;
Molecular biology

Abstract:  A set of five carbohydrate-specific monoclonal
antibodies (mAbs) were used to probe the ultrastructure of the
walls of the soybean pathogen Phytophthora megasperma f.sp.
glycinea, using a combination of immunofluorescence and
immuno-gold labelling techniques. Results with beta-1,3
glucan-specific antibodies suggest that beta-1,3 glucans are
present throughout the walls of both germ tubes and cysts, but
are more prevalent in the outer portion. In addition, beta-1,3
glucans on the surface of hyphal walls, but not cysts, are
closely associated with other material, most likely protein,
that sterically hinders antibody binding except to non-
reducing terminal residues. An antibody whose epitope involved
both beta-1,4 and beta-1,3 glucosyl linkages bound
predominantly to the inner portion of the hyphal wall.
However, fluorescent labelling with this antibody suggested
that beta-1,4 linkages are present on the exterior of P.
megasperma f.sp glycinea walls as well. Staining with another
antibody indicates that changes in wall composition occur over
50-100 micrometers from the hyphal tip, a greater distance
than previously supposed. The role of the antigens recognized
by these mAbs in the plant-pathogen interaction is not known,
but potential uses of these and other mAbs are discussed.


161                                 NAL Call. No.: 448.3 J823
Localization of transposon insertions in pathogenicity mutants
of Erwinia amylovora and their biochemical characterization.
Bellemann, P.; Geider, K.
Reading : Society for General Microbiology; 1992 May.
The Journal of general microbiology v. 138 (pt.5): p. 931-940;
1992 May. Includes references.

Language:  English

Descriptors: Pyrus communis; Blight; Bacteriophages; Erwinia
amylovora; Mutants; Transposable elements; Plasmids;
Insertional mutagenesis; Cosmids; Complementation; Virulence;
Symptoms

Abstract:  Transposon Tn5, on a mobilizable ColE1 plasmid, on
a Ti plasmid derepressed for bacterial transfer, and on the
bacteriophage fd genome, was used to construct pathogenicity
mutants of the fire blight pathogen Erwinia amylovora. Eleven
nonpathogenic mutants were isolated from 1600 independent
mutants screened. These mutants were divided into three types:
auxotrophs, exopolysaccharide (EPS)-deficient mutants and a
mutant of the dsp phenotype. According to their insertion
sites the Tn5 mutants were mapped into several classes. Some
of the mutants could be complemented with cosmid clones from a
genomic library of the parent strain for EPS production on
minimal agar. EPS-deficient mutants and the dsp mutant could
complement each other to produce virulence symptoms on pear
slices.


162                                  NAL Call. No.: 448.3 J82
Location and cloning of the ketal pyruvate transferase gene of
Xanthomonas campestris.
Marzocca, M.P.; Harding, N.E.; Petroni, E.A.; Cleary, J.M.;
Ielpi, L. Washington, D.C. : American Society for
Microbiology; 1991 Dec. Journal of bacteriology v. 173 (23):
p. 7519-7524; 1991 Dec.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris; Genes; Transferases;
Pyruvic acid; Cloning; Gene expression; Xanthan; Biosynthesis

Abstract:  Genes required for xanthan polysaccharide synthesis
(xps) are clustered in a DNA region of 13.5 kb in the
chromosome of Xanthomonas campestris. Plasmid pCHC3 containing
a 12.4-kb insert of xps genes has been suggested to include a
gene involved in the pyruvylation of xanthan gum (N. E.
Harding, J. M. Clearn, D. K. Cabanas, I. G. Rosen, and K. S.
Kang, J. Bacteriol. 169:2854-2861, 1987). An essential step
toward understanding the biosynthesis of xanthan gum and to
enable genetic manipulation of xanthan structure is the
determination of the biochemical function encoded by the xps
genes. On the basis of biochemical characterization of an X.
campestris mutant which produces pyruvate-free xanthan gum,
complementation studies, and heterologous expression, we have
identified the gene coding for the ketal pyruvate transferase
(kpt) enzyme. This gene was located on a 1.4-kb BamHI fragment
of pCHC3 and cloned in the broad-host-range cloning vector
PRK404. An X. campestris kpt mutant was constructed by mini-
Mu(Tetr) mutagenesis of the cloned gene and then by
recombination of the mutation into the chromosome of the wild-
type strain.


163                                   NAL Call. No.: 500 N21P
Mechanism of phenolic activation of Agrobacterium virulence
genes: development of a specific inhibitor of bacterial
sensor/response systems. Hess, K.M.; Dudley, M.W.; Lynn, D.G.;
Joerger, R.D.; Binns, A.N. Washington, D.C. : The Academy;
1991 Sep01.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (17): p. 7854-7858; 1991 Sep01. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Crown gall; Gene
expression; Glycosides; Phenols; Plasmids; Virulence

Abstract:  The aglycone of the dihydrodiconiferyl alcohol
glycosides, a series of phenolic growth factors able to
substitute for some of the hormone requirements of tobacco
cell division, are also potent inducers of virulence gene
expression in Agrobacterium tumefaciens. However, these
factors do not conform to the previously established
structural requirements necessary for vir expression.
Systematic evaluation of the structural requirements of these
inducers has led to a model detailing the role of the
phenolics in induction. With this model, a specific inhibitor
of vir induction has been developed. This inhibitor does not
affect the induction of other genes on the Ti plasmid but
irreversibly blocks vir expression. The inhibitor has been
used to show that the inducing phenolics must be constantly
present to maintain expression of the vir regulon.


164                                   NAL Call. No.: QH426.C8
Meiotic and mitotic stability of transforming DNA in the
phytopathogenic fungus Magnaporthe grisea.
Tooley, P.W.; Leung, H.; Leong, S.A.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (1): p. 55-60; 1992.  Includes
references.

Language:  English

Descriptors: Magnaporthe grisea; Genetic transformation; Dna;
Stability; Meiosis; Mitosis; Genetic markers; Segregation;
Hygromycin b; Drug resistance; Phosphotransferases; Plasmids;
Recombination; Virulence; Fungal diseases; Oryza sativa;
Eragrostis curvula

Abstract:  Magnaporthe grisea was transformed with cosmid
pAN7-2 encoding hygromycin B resistance but containing no
homology with the M. grisea genome. Rearrangement of the
integrated DNA was detected in several hygromycin B-resistant
progeny from cross Guy11-T10-1 (a single-copy integration site
transformant) X 2539 sensitive wild-type parent), but not in
hygromycin B-resistant progeny from four other crosses.
Transformants produced typical lesions when inoculated onto
host plants. Southern hybridization revealed rearrangements of
integrated DNA in single conidial isolates of high-copy
transformant 2539-T1-1 re-isolated from host plants,
characterized by excision of one or more copies of the
transforming plasmid. Plasmid loss and rearrangement were also
observed within single conidial isolates derived from
transformant 2539-T1-1 following ten asexual generations on
non-selective agar medium. These examples of instability of
integrated DNA in M. grisea transformants suggest that caution
should be exercised in the use of transformation for assessing
the phenotypic effects of specific introduced genes.


165                                  NAL Call. No.: 464.8 P56
A method for genetic analysis of Glomerella graminicola
(Colletotrichum graminicola) from maize.
Vaillancourt, L.J.; Hanau, R.M.
St. Paul, Minn. : American Phytopathological Society; 1991
May. Phytopathology v. 81 (5): p. 530-534. ill; 1991 May. 
Includes references.

Language:  English

Descriptors: Zea mays; Infection; Colletotrichum graminicola;
Strains; Mating; Ascospores; Progeny; Recombination;
Segregation; Markers; Crosses; Mutants; Gene transfer; Genetic
analysis

Abstract:  Strains derived from nine different isolates of
Colletotrichum graminicola from maize participated in the
production of perithecia when incubated on pieces of
autoclaved corn leaves in a humidity chamber. Matings occurred
between self-fertile and self-sterile strains, and also
between certain self-sterile strains. As many as 200 ascospore
progeny were recovered easily from individual perithecia.
Characterization of progeny showed that sexual recombination
and Mendelian segregation of distinct traits could be
detected. Segregation of markers for chlorate resistance
(ChlR), benomyl resistance (BmlR), and melanin deficiency
(Mel-) approximated a 1:1 ratio and defined three separate
linkage groups. Crosses involving a pyrimidine auxotroph (Pyr-
) showed 2:1 segregation (Pyr+:Pyr-) and linkage between
markers for Pyr- and ChlR. Attempts to combine multiple
markers resulted in successful construction of a Mel- Pyr-
self-fertile strain that was crossed with a BmlR strain to
produce offspring with a triple-mutant Mel- Pyr- BmlR
phenotype.


166                                  NAL Call. No.: QK710.P62
Mismatch-specific DNA breakdown in nuclear extract from
tobacco (Nicotiana tabacum) callus.
Cerovic, G.; Bozin, D.; Dimitrijevic, B.
Dordrecht : Kluwer Academic Publishers; 1991 Oct.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 17
(4): p. 887-894; 1991 Oct. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Agrobacterium tumefaciens; Dna
repair; Nucleotide sequences; Dna modification; Degradation;
Enzyme activity; Deoxyribonuclease i; Nuclei; Callus; Genetic
transformation; Crown gall

Abstract:  Mismatch-specific enzymatic activity was sought for
in nuclei from normal and transformed plant cells originating
from tobacco (Nicotiana tabacum) callus and crown gall tumor
induced by Agrobacterium tumefaciens. The specific enzymatic
activity was assayed with substrates derived from synthetic
oligonucleotides (19-mer sequences corresponding to the human
K-ras gene). Single-base changes in the middle of the sequence
were the basis for creating heteroduplexes with all eight
mismatches. Homo- and heteroduplexes were ligated in a size
ladder and used as substrates. We detected mismatch-specific
DNA breakdown and determined basic requirements for the
reactions. Kinetic analysis indicates the following reactivity
order of preference: C: A = C: C = C: T > G: T approximately
A: A approximately G: A approximately G: G approximately T: T
> > G: C. It can be said now that specific mismatch
recognition and repair activities have been detected in all
kingdoms of living species.


167                                   NAL Call. No.: QH426.C8
Mitotic stability of transforming DNA is determined by its
chromosomal configuration in the fungus Cochliobolus
heterostrophus.
Keller, N.P.; Bergstrom, G.C.; Yoder, O.C.
Berlin, W. Ger. : Springer International; 1991.
Current genetics v. 19 (3): p. 227-233; 1991.  Includes
references.

Language:  English

Descriptors: Cochliobolus heterostrophus; Genetic
transformation; Dna; Stability; Mitosis; Plasmids; Dna
methylation; Deletions; Homologous recombination; Chromosomes;
Pathogenesis; Fungal diseases; Zea mays

Abstract:  Cochliobolus heterostrophus was transformed with a
plasmid (pH1S) containing a bacterial gene (hygB), which
confers resistance to the antibiotic hygromycin B when under
control of an 838-bp fragment of promoter 1 from C.
heterostrophus. The plasmid integrated at either homologous
(52% single copy, 33% tandemly repeated copies) or ectopic (4%
single copy, 11% tandemly repeated copies) sites on different
chromosomes, resulting in four distinct configurations of
integrated DNA. All four configurations were highly stable
during mitotic growth; virtually no loss of integrated DNA was
detected after five subcultures on nonselective medium or
after seven cycles of pathogenesis on maize, the normal host
of this fungus. However, deletion of integrated DNA was
detected after eight or more disease cycles. The frequency of
deletion depended on the configuration of the recombinant
chromosome. A single copy of pH1S integrated at an homologous
site was flanked by direct repeats of the target sequence and
was least stable; up to 50% of the population lacked
integrated DNA after 12 disease cycles. A single copy
integrated at an ectopic site had no repeated DNA directly
associated with it and was the most stable; no deletions were
detected after 12 disease cycles. Tandemly repeated copies of
pH1S integrated at either homologous or ectopic sites appeared
to have intermediate stability; 2-18% of each population lost
at least one copy after 12 disease cycles, although in no case
were all copies deleted. Cytosine residues of integrated DNA
were methylated during mitotic growth, but this had no
apparent effect on the expression of hygB.


168                                NAL Call. No.: QH431.A1G43
Mobilization of Agrobacterium rhizogenes root-inducing
plasmids into the cells of Rhizobium meliloti, Rhizobium
galegae, and Rhizobium leguminosarum biovar trifolii.
Novikova, N.I.; Pavlova, E.A.; Safronova, V.I.; Zabelina, N.K.
New York, N.Y. : Consultants Bureau; 1991 Aug.
Soviet genetics v. 27 (2): p. 154-161; 1991 Aug.  Translated
from: Genetika, v. 27 (2), 1991, p. 229-237. (QH431.A1G4). 
Includes references.

Language:  English; Russian

Descriptors: Agrobacterium rhizogenes; Rhizobium meliloti;
Rhizobium leguminosarum; Rhizobium trifolii; Rhizobium;
Plasmids; Genetic transformation; Nodulation; Roots; Growth;
Virulence; Nitrogen fixation; Nicotiana tabacum; Medicago
sativa; Galega; Plant disorders

Abstract:  Root-inducing plasmids (pRi) of two Agrobacterium
rhizogenes strains were marked with transposon Tn5-mob. Using
plasmid RP4-4 the pRi::tn5-mob were mobilized with a frequency
of 10(-6)-10(-7) into the cells of the nodule bacteria of
Medicago, Trifolium, and Galega. The transconjugants of the
Trifolium and Galega nodule bacteria stimulated the
proliferation of "hairy roots" on tobacco leaves, while the
transconjugants of Rhizobium meliloti (pRi) were
nonpathogenic, actively fixed nitrogen in symbiosis with
alfalfa, and were more virulent than the initial recipient
strain. The presence of pRi in the cells of Galega nodule
bacteria led to a reduction in the number of nodules formed by
them on the roots of the host plant. In the inoculated clover
plants the rate of nodulation did not change, but three weeks
after the day of inoculation with recombinant strains we
observed inhibition of the level of acetylene reductase
activity, leading ultimately to development of inefficient
symbiosis.


169                                 NAL Call. No.: 464.8 P566
Molecular and cellular aspects of Dutch elm disease.
Sticklen, M.B.; Bolyard, M.G.; Hajela, R.K.; Duchesne, L.C.
Saint-Hyacinthe : Quebec Society for the Protection of Plants;
1991. Phytoprotection v. 72 (1): p. 1-13; 1991.  Literature
review.  Includes references.

Language:  English

Descriptors: Ulmus Americana; Ceratocystis ulmi; Fungal
diseases; Mycotoxins; Phytotoxicity; Pathogenesis; Molecular
biology; Molecular genetics; Defense mechanisms; Literature
reviews; Fungal antagonists; Disease resistance; Scolytidae;
Disease vectors


170                                 NAL Call. No.: 464.8 AN72
Molecular and genetic analysis of toxin production by
pathovars of Pseudomonas syringae.
Gross, D.C.
Palo Alto, Calif. : Annual Reviews, Inc; 1991.
Annual review of phytopathology v. 29: p. 247-278; 1991. 
Literature review. Includes references.

Language:  English

Descriptors: Pseudomonas syringae; Pathotypes; Virulence;
Genetic variation; Phytotoxins; Biosynthesis; Biochemical
pathways; Phaseolotoxin; Genetic analysis; Genes; Cloning;
Molecular biology; Mutants; Plasmids; Strain differences; Gene
expression; Literature reviews; Host parasite relationships


171                                   NAL Call. No.: QR245.F8
Molecular approaches to the analysis of pathogenicity genes
from fungi causing plant disease.
Garber, R.C.
New York : Plenum Press; 1991.
The Fungal spore and disease initiation in plants and animals
/ edited by Garry T. Cole and Harvey C. Hoch. p. 483-502;
1991.  Includes references.

Language:  English

Descriptors: Plant pathogenic fungi; Pathogenicity; Genes;
Enzymes; Cloning; Mutants; Gene transfer; Isolation
techniques; Molecular biology


172                                  NAL Call. No.: QK710.P62
Molecular basis for novel root phenotypes induced by
Agrobacterium rhizogenes A4 on cucumber.
Amselem, J.; Tepfer, M.
Dordrecht : Kluwer Academic Publishers; 1992 Jun.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 19
(3): p. 421-432; 1992 Jun. Includes references.

Language:  English

Descriptors: Cucumis sativus; Agrobacterium rhizogenes;
Genetic transformation; Stems; Explants; Roots; Phenotypes;
Plant morphology; Tissue culture; Dna; Plasmids; Restriction
mapping; Genes; Gene expression; Messenger  RNA; Molecular
mapping

Abstract:  We have used the wild-type Agrobacterium rhizogenes
strain A4 to induce roots on cucumber stem explants. Cultures
of transformed roots obtained that were capable of hormone-
autonomous growth could be grouped in three phenotypic
classes. Of particular interest were extremely thick roots of
a type not previously described. Characterization of the
transferred DNA and of the expression of the corresponding
genes allowed us to determine that the genes rolABC of the TL
region of the Ri plasmid are sufficient to induce thin roots
similar to those observed in other species, while the aux
genes of the TR region are sufficient to induce thick roots.
Among clones bearing the aux genes, there was a correlation
between level of expression of aux2 and root phenotype.


173                                  NAL Call. No.: TA166.T72
Molecular biology of Erwinia: from soft-rot to antileukaemics.
Robert-Baudouy, J.
New York, N.Y. : Elsevier Science Publishing Co; 1991 Sep.
Trends in biotechnology v. 9 (9): p. 325-329; 1991 Sep. 
Includes references.

Language:  English

Descriptors: Erwinia; Molecular biology; Biotechnology;
Cloning; Escherichia coli; Industrial microbiology; Enzyme
preparations; Food processing; Fruit juices; Ascorbic acid

Abstract:  Soft-rot Erwinia has served to model the regulatory
mechanisms in plant-pathogen interactions, and studies have
revealed the extracellular pectinolytic, cellulolytic and
proteolytic enzymes to be major virulence factors in Erwinia
pathogenesis. Apart from its agricultural significance,
Erwinia is of increasing interest as an industrial microbe:
the Erwinia secretory apparatus, when cloned in Escherichia
coli, enables this organism to secrete heterologous Erwinia
pectinases, and molecular studies in Erwinia have facilitated
the industrial production of pectin methylesterase (important
in fruit-juice processing), vitamin C and the antileukaemic
asparaginase.


174                                  NAL Call. No.: QK600.B72
Molecular biology of fungal plant pathogenicity.
Oliver, R.P.; Farman, M.L.; Talbot, N.J.; McHale, M.T.
Cambridge : Cambridge University Press; 1991.
Symposium series - British Mycological Society (18): p.
170-182; 1991.  In the series analytic: Applied molecular
genetics of fungi / edited by J. F. Peberdy, C. E. Caten, J.
E. Ogden and J. W. Bennett. Symposium of the British
Mycological Society held at the University of Nottingham,
April 1990. Literature review.  Includes references.

Language:  English

Descriptors: Plant pathogenic fungi; Genes; Pathogenicity;
Virulence; Races; Fungal diseases; Genetic transformation;
Reporter genes; Transposable elements; Insertional
mutagenesis; Karyotypes; Literature reviews


175                                  NAL Call. No.: 448.3 J82
Molecular characterization and expression analysis of the
anthranilate synthase gene of Pseudomonas syringae subsp.
savastanoi.
Da Costa E Silva, O.; Kosuge, T.
Washington, D.C. : American Society for Microbiology; 1991
Jan. Journal of bacteriology v. 173 (2): p. 463-471; 1991 Jan. 
Includes references.

Language:  English

Descriptors: Pseudomonas syringae; Ligases; Gene expression;
Amino acid sequences; Nucleotide sequences; Genetic
regulation; Tryptophan

Abstract:  The trpE gene, which encodes the large component of
the enzyme anthranilate synthase, was isolated from a
Pseudomonas syringae subsp. savastanoi (P. savastanoi) cosmid
library. Cosmids that complemented an Escherichia coli trpE
mutation contained a gene whose product is 86% homologous at
the deduced amino acid level to TrpE of Pseudomonas aeruginosa
and Pseudomonas putida. Amino acid sequence comparison with
other TrpE sequences revealed the existence of conserved
regions between the procaryotic and eucaryotic polypeptide
sequences analyzed, regions that might be of functional
importance. We also report on studies on the expression
pattern of this gene. We analyzed the promoter activity of a
trpE::lacZ transcriptional fusion, the relative amount of trpE
steady-state mRNA, and the activity of anthranilate synthase
from cells grown in minimal medium with or without exogenously
added tryptophan and in complete medium. We concluded that
under the conditions tested, expression of the trpe gene of P.
savastanoi is independent of the concentration of tryptophan
in the culture medium. Implications of such an expression
pattern on the virulence of this bacterium are discussed.


176                                NAL Call. No.: 442.8 B5236
Molecular cloning and nucleotide sequence of a pectin lyase
gene from Pseudomonas marginalis N6301.
Nikaidou, N.; Kamio, Y.; Izaki, K.
Orlando, Fla. : Academic Press; 1992 Jan15.
Biochemical and biophysical research communications v. 182
(1): p. 14-19; 1992 Jan15.  Includes references.

Language:  English

Descriptors: Pseudomonas marginalis; Pectins; Lyases; Genes;
Clones; Gene expression; Nucleotide sequences; Amino acid
sequences; Escherichia coli; Erwinia carotovora

Abstract:  A pectin lyase (PNL;EC4.2.2.10) gene of Pseudomonas
marginalis N6301 was cloned and expressed in Escherichia coli.
We purified PNL from P. marginalis N6301 and determined N-
terminal 33 amino acids sequence. From this sequence, we
synthesized two oligonucleotide probes. From the analysis of
Southern hybridization, 2.1kb EcoRI-SmaI fragment from the
chromosomal DNA of P. marginalis was found to hybridize with
oligonucleotide probes. Then, we cloned the fragment into
pUC119 vector and transformed into E.coli DH5 alpha. A plasmid
thus obtained was designated as pPNL6301. E. coli DH5 alpha
harboring pPNL6301 expressed PNL activity. The nucleotide
sequence of pnl gene in the plasmid pPNL6301 encoding PNL from
P. marginalis N6301 was determined. The structural gene of pnl
consisted of 936 base pairs. An open reading frame that
encodes a 34, 103 dalton polypeptide composed of 312 amino
acids was assigned. The molecular weight of the polypeptide
predicted from the amino acid composition was close to that of
PNL. of P. marginalis N6301 determined. The nucleotide
sequence of the LexA binding 5'-flanking region of pnl gene
showed the presence of the consensus sequence of LexA site,
Pribnow box and ribosome binding site as found in Escherichia
coli. The amino acid sequence homology of PNLs and nucleotide
sequence homology of pnl gene between P. marginalis N6301 and
E. carotovora Er were 60.8% and 57.2%, respectively.


177                                NAL Call. No.: SB732.6.M65
Molecular cloning of an aepA gene that activates production of
extracelular pectolytic, cellulolytic, and proteolytic enzymes
in Erwinia carotovora subsp. carotovora.
Murata, H.; McEvoy, J.L.; Chatterjee, A.; Collmer, A.;
Chatterjee, A.K. St. Paul, Minn. : APS Press; 1991 May.
Molecular plant-microbe interactions : MPMI v. 4 (3): p.
239-246; 1991 May. Includes references.

Language:  English

Descriptors: Erwinia carotovora subsp. carotovora; Enzyme
activity; Pectate lyase; Polygalacturonase; Cellulase;
Proteinases; Mutants; Strains; Biosynthesis; Genes; Cosmids;
Characterization; Molecular genetics; Cloning


178                                  NAL Call. No.: 448.3 AP5
Molecular cloning of genes related to aflatoxin biosynthesis
by differential screening.
Feng, G.H.; Chu, F.S.; Leonard, T.J.
Washington, D.C. : American Society for Microbiology; 1992
Feb01. Applied and environmental microbiology v. 58 (2): p.
455-460; 1992 Feb01. Includes references.

Language:  English

Descriptors: Aspergillus parasiticus; Aflatoxins;
Biosynthesis; Genes; Cloning

Abstract:  A differential hybridization strategy was used to
clone genes associated with aflatoxin biosynthesis. A genomic
library, formed between nuclear DNA and the PUC19 plasmid, was
screened with three different cDNA probes by the colony
hybridization procedure. Nineteen clones were selected; all
were positively correlated with and presumably enriched with
genes associated with aflatoxin production. Some of these
clones were further characterized by using them as probes in
Northern (RNA blot) hybridizations. Five clones hybridized
strongly with some polyadenylated RNAs formed during the
transition to or during idiophase when aflatoxin was produced.
However, little or no corresponding hybridization occurred
with polyadenylated RNAs formed in early and mid-log growth
phase. Two of the clones were further used as probes to
hybridize with polyadenylated RNAs formed under aflatoxin-
permissive and nonpermissive temperatures. Hybridization
occurred with RNA species formed under the permissive
temperature only.


179                                  NAL Call. No.: 442.8 Z34
Molecular cloning of ompRS, a regulatory locus controlling
production of outer membrane proteins in Erwinia carotovora
subsp. carotovora. Karlsson, M.B.; Pirhonen, M.; Saarilahti,
H.T.; Palva, E.T. Berlin, W. Ger. : Springer International;
1991 May.
M G G : Molecular and general genetics v. 226 (3): p. 353-360;
1991 May. Includes references.

Language:  English

Descriptors: Erwinia carotovora subsp. carotovora; Escherichia
coli; Loci; Cloning; Protein synthesis; Bacterial proteins;
Membranes; Dna hybridization; Complementation; Mutants;
Restriction mapping; Gene expression; Genetic regulation;
Osmoregulation; Virulence; Nicotiana tabacum; Solanum
tuberosum

Abstract:  A locus, ompRS, controlling synthesis of outer
membrane proteins was cloned from Erwinia carotovora subsp.
carotovora (Ecc) by complementation of an Escherichia coli
ompR-envZ mutant. The Ecc ompRS locus was both structurally
and functionally similar to the ompR-envZ operon controlling
porin gene expression in E. coli as shown by DNA hybridization
and complementation of E. coli ompR and envZ mutants.
Furthermore, introduction of ompRS into E. coli delta (ompR-
envZ) strains restored the osmoregulation of the major outer
membrane protein genes ompC and ompF. Maxicell analysis of
ompRS-carrying plasmids suggested that proteins similar in
size to the E. coli ompR and envZ gene products were encoded
by the Ecc ompR and ompS genes, respectively. Introduction of
an ompRS transposon mutant onto the Ecc chromosome by marker
exchange mutagenesis showed that ompRS is essential for
production of a major outer membrane porin in Ecc. This
mutational defect could be complemented by clones carrying Ecc
ompRS or E. coli ompR envZ. The lack of the porin did not,
however, compromise the virulence of these Ecc mutants.


180                                 NAL Call. No.: 464.8 AN72
Molecular genetic analysis of the rice blast fungus,
Magnaporthe grisea. Valent, B.; Chumley, F.G.
Palo Alto, Calif. : Annual Reviews, Inc; 1991.
Annual review of phytopathology v. 29: p. 443-467; 1991. 
Literature review. Includes references.

Language:  English

Descriptors: Oryza sativa; Magnaporthe grisea; Pathogenicity;
Genes; Genetic analysis; Host specificity; Molecular genetics;
Mutants; Genetic transformation; Nucleotide sequences;
Molecular mapping; Pathogenesis; Genetic variation; Literature
reviews


181                                 NAL Call. No.: 448.3 J823
Molecular genetics of Pseudomonas syringae pathovar pisi:
plasmid involvement in cultivar-specific incompatibility.
Bavage, A.D.; Vivian, A.; Atherton, G.T.; Taylor, J.D.; Malik,
A.N. Reading : Society for General Microbiology; 1991 Sep.
The Journal of general microbiology v. 137 (pt.9): p.
2231-2239; 1991 Sep. Includes references.

Language:  English

Descriptors: Pisum sativum; Cultivars; Pseudomonas syringae
pv. pisi; Mutants; Clones; Genes; Cosmids; Plasmids; Dna;
Virulence; Varietal resistance; Genetic resistance;
Phenotypes; Molecular genetics

Abstract:  A mutant (PF24) of the race 1 strain, 299A, of
Pseudomonas syringae pv.pisi has been characterized in terms
of its interactions with pea (Pisum sativum) cultivars. The
mutant showed a changed reaction (avirulence to virulence)
with a group of pea cultivars, including cvs. Belinda and
Puget, previously thought to contain resistance genes R1 and
R3. Avirulence towards cv. Puget was restored by transfer of
any one of five cosmid clones from a race 3 (strain 870A) gene
library to a rifampicin-resistant derivative of PF24. These
observations were in agreement with a revised race-specific
resistance genotype for Belinda and similar cultivars
comprising a single resistance gene, R3. An incompatible
interaction was observed between strain PF24 and cvs. Vinco
(postulated to harbour race-specific resistance genes R1, R2,
R3 and R5) and Hurst's Greenshaft (R4 and possibly R1),
indicating that the mutant retains at least one avirulence
gene (A1 or A1 and A4). Mutant PF24 showed loss of a cryptic
plasmid (pAV212) compared with its progenitor, strain 299A. A
subclone (pAV233) of one of the race 3 restoration clones
showed strong hybridization with similar-sized digestion
fragments in race 3 plasmid DNA, confirming the A3 gene to be
plasmid-borne. Strong cross-hybridization was also observed
with a single 3.27 kb EcoR1 fragment of plasmid DNA present in
strain 299A but absent from strain PF24. This is consistent
with the corresponding A3 determinant being located on pAV212
in the race I strain 299A. The novel avirulence gene
corresponding to A3 in strain 870A is provisionally designated
avrPpi3. A spontaneous race-change variant (strain 1759, which
expressed no avirulence phenotype toward the pea differential
cultivars) was derived from the race 3 strain 870A. This race
6 strain and a wild isolate of a race 6 strain both lacked
plasmid DNA sequences corresponding to the insert in pAV233.


182                                NAL Call. No.: QL391.N4J62
Molecular transfer of nematode resistance genes.
Williamson, V.M.; Ho, J.Y.; Ma, H.M.
Lake Alfred, Fla. : Society of Nematologists; 1992 Jun.
Journal of nematology v. 24 (2): p. 234-241; 1992 Jun. 
Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Meloidogyne; Pest
resistance; Transgenics; Agrobacterium tumefaciens; Dna;
Genes; Cloning

Abstract:  Recombinant DNA techniques have been used to
introduce agronomically valuable traits, including resistance
to viruses, herbicides, and insects, into crop plants.
Introduction of these genes into plants frequently involves
Agrobacterium-mediated gene transfer. The potential exists for
applying this technology to nematode control by introducing
genes conferring resistance to nematodes. Transferred genes
could include those encoding products detrimental to nematode
development or reproduction as well as cloned host resistance
genes. Host genes that confer resistance to cyst or root-knot
nematode species have been identified in many plants. The best
characterized is Mi, a gene that confers resistance to root-
knot nematodes in tomato. A map-based cloning approach is
being used to isolate the gene. For development of a detailed
map of the region of the genome surrounding Mi, DNA markers
genetically linked to Mi have been identified and analyzed in
tomato lines that have undergone a recombination event near
Mi. The molecular map will be used to identify DNA
corresponding to Mi. We estimate that a clone of Mi will be
obtained in 2-5 years. An exciting prospect is that
introduction of this gene will confer resistance in plant
species without currently available sources of resistance.


183                                 NAL Call. No.: QH442.A1G4
Mutagenesis of a tryptophan codon from TGG to TGA in the cat
gene does not prevent its expression in the helical mollicute
Spiroplasma citri. Stamburski, C.; Renaudin, J.; Bove, J.M.
Amsterdam : Elsevier Science Publishers; 1992.
Gene v. 110 (1): p. 133-134; 1992.  Includes references.

Language:  English

Descriptors: Spiroplasma citri; Genetic transformation;
Reporter genes; Chloramphenicol acetyltransferase; Genetic
code; Tryptophan; Mutagenesis; Gene expression; Escherichia
coli; Induced mutations

Abstract:  When the first TGG tryptophan codon of the
chloramphenicol acetyltransferase encoding gene, cat, is
mutated to the opal stop codon TGA, very little or no activity
can be detected in Escherichia coli; in contrast, in the
helical mollicute, Spiroplasma citri, the mutated and non-
mutated cat genes are expressed equally well.


184                                   NAL Call. No.: 500 N21P
Mutants of Agrobacterium tumefaciens with elevated vir gene
expression. Pazour, G.J.; Ta, C.N.; Das, A.
Washington, D.C. : The Academy; 1991 Aug15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (16): p. 6941-6945; 1991 Aug15. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Crown gall; Gene
expression; Genotypes; Molecular genetics; Mutagenesis;
Mutants; Plasmids; Strains

Abstract:  Expression of Agrobacterium tumefaciens virulence
(vir) genes requires virA, virG, and a plant-derived inducing
compound such as acetosyringone. To identify the critical
functional domains of virA and virG, a mutational approach was
used. Agrobacterium A136 harboring plasmid pGP159, which
contains virA, virG, and a reporter virB:lacZ gene fusion, was
mutagenized with UV light or nitrosoguanidine. Survivors that
formed blue colonies on a plate containing 5-bromo-4-chloro-3-
indolyl beta-D-galactoside were isolated and analyzed.
Quantification of beta-galactosidase activity in liquid assays
identified nine mutant strains. By plasmid reconstruction and
other procedures, all mutations mapped to the virA locus.
These mutations caused an 11- to 560-fold increase in the
vegetative level of virB:lacZ reporter gene expression. DNA
sequence analysis showed that the mutations are located in
four regions of VirA: transmembrane domain one, the active
site, a glycine-rich region with homology to ATP-binding
sites, and a region at the C terminus that has homology to the
N terminus of VirG.


185                                NAL Call. No.: SB732.6.M65
Mutants of the Agrobacterium tumefaciens virA gene exhibiting
acetosyringone-independent expression of the vir regulon.
Ankenbauer, R.G.; Best, E.A.; Palanca, C.A.; Nester, E.W. St.
Paul, Minn. : APS Press; 1991 Jul.
Molecular plant-microbe interactions : MPMI v. 4 (4): p.
400-406; 1991 Jul. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Mutants; Induced
mutations; Genes; Virulence; Genetic regulation; Phenolic
compounds; Transcription; Gene expression; Phenotypes;
Plasmids; Gene mapping; Nucleotide sequences; Amino acid
sequences; Molecular genetics


186                                  NAL Call. No.: 448.3 J82
Mutation of the miaA gene of Agrobacterium tumefaciens results
in reduced vir gene expression.
Gray, J.; Wang, J.; Gelvin, S.B.
Washington, D.C. : American Society for Microbiology; 1992
Feb. Journal of bacteriology v. 174 (4): p. 1086-1098; 1992
Feb.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Genes; Mutations;
Virulence; Gene expression; Nucleotide sequences; Amino acid
sequences

Abstract:  vir regulon expression in Agrobacterium tumefaciens
involves both chromosome- and Ti-plasmid-encoded gene
products. We have isolated and characterized a new chromosomal
gene that when mutated results in a 2- to 10-fold reduction in
the induced expression of vir genes by acetosyringone. This
reduced expression occurs in AB minimal medium (pH 5.5)
containing either sucrose or glucose and containing phosphate
at high or low concentrations. The locus was cloned and used
to complement A. tumefaciens strains harboring Tn5 insertions
in the gene. Sequence analysis of this locus revealed an open
reading frame with strong homology to the miaA locus of
Escherichia coli and the mod5 locus of Saccharomyces
cerevisiae. These genes encode tRNA: isopentenyltransferase
enzymes responsible for the specific modification of the A-37
residue in UNN codon tRNA species. The function of the
homologous gene in A. tumefaciens was proven by genetic
complementation of E. coli miaA mutant strains. tRNA
undermodification in A. tumefaciens miaA mutant strains may
reduce vir gene expression by causing a reduced translation
efficiency. A slight reduction in the virulence of these
mutant Agrobacterium strains on red potato plants, but not on
tobacco, tomato, kalanchoe, or sunflower plants, was observed.


187                                  NAL Call. No.: 448.3 J82
Mutational analysis of Agrobacterium tumefaciens virD2:
tyrosine 29 is essential for endonuclease activity.
Vogel, A.M.; Das, A.
Washington, D.C. : American Society for Microbiology; 1992
Jan. Journal of bacteriology v. 174 (1): p. 303-308; 1992 Jan. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Polypeptides;
Tyrosine; Phenylalanine; Nucleases; Enzyme activity

Abstract:  Agrobacterium tumefaciens VirD2 polypeptide, in the
presence of VirD1, catalyzes a site- and strand-specific
nicking reaction at the T-DNA border sequences. VirD2 is found
tightly attached to the 5' end of the nicked DNA. The protein-
DNA complex is presumably formed via a tyrosine residue of
VirD2 (F. Durrenberger, A. Crameri, B. Hohn, and Z.
Koukolikova-Nicola, Proc. Natl. Acad. Sci. USA 86:9154-9158,
1989). A mutational approach was used to study whether a
tyrosine residue(s) of VirD2 is required for its activity. By
site-specific mutagenesis, a tyrosine (Y) residue at position
29, 68, 99, 119, 121, 160, or 195 of the octopine Ti plasmid
pTiA6 VirD2 was altered to phenylalanine (F). The Y-29-F or
Y-121-F mutation completely abolished nicking activity of
VirD2 in vivo in Escherichia coli. Two other substitutions,
Y-68-F and Y-160-F, drastically reduced VirD2 activity. A
substitution at position 99, 119, or 195 had no effect on
VirD2 activity. Additional mutagenesis experiments showed that
at position 29, no other amino acid could substitute for
tyrosine without destroying VirD2 activity. At position 121,
only a tryptophan (W) residue could be substituted. This,
however, yielded a mutant protein with significantly reduced
VirD2 activity. The nicked DNA from strains bearing a Y-68-F,
Y-99-F, Y-119-F, Y-160-F, Y-195-F, or Y-121-W mutation in
VirD2 was always found to contain a tightly linked protein.


188                                  NAL Call. No.: 464.8 P56
Mycelial incompatibility and molecular markers identify
genetic variability in field populations of Sclerotinia
sclerotiorum.
Kohn, L.M.; Stasovski, E.; Carbone, I.; Royer, J.; Anderson,
J.B. St. Paul, Minn. : American Phytopathological Society;
1991 Apr. Phytopathology v. 81 (4): p. 480-485. ill; 1991 Apr. 
Includes references.

Language:  English

Descriptors: Brassica napus; Sclerotinia sclerotiorum;
Strains; Mycelium; Compatibility; Incompatibility; Molecular
genetics; Heterogeneity; Genetic markers; Dna; Dna
fingerprinting; Characterization; Phenotypes; Genetic
polymorphism

Abstract:  Sixty-three sclerotial strains of Sclerotinia
sclerotiorum were obtained from transects in two fields of
canola (Brassica napus) in Ontario. Mycelial pairings of the
strains in all combinations on agar medium produced either an
incompatible reaction in which a reaction line between the two
strains developed in the interaction zone, or a compatible
reaction in which no reaction line developed. The reaction
line was a distinct discontinuity between the two strains,
visible as a red line on the colony reverse in pairings made
on medium amended with red food coloring. Among the 33 strains
from the first field, six mycelial compatibility groups (MCGs)
were recognized, the largest group including 19 strains. Among
the 30 strains from the second field, many more MCGs were
defined. In pairings of 10 monosporous strains from each of
six apothecia collected along the transects, all sibling
monosporous strains were compatible and no segregation for
mycelial compatibility was observed among siblings. Analysis
with three molecular markers indicated that each of the MCGs
was genetically uniform. With one of these markers, each MCG
was uniquely fingerprinted. This fingerprint was produced by a
random fragment of nuclear DNA (approximately 4.5 kb) from S.
sclerotiorum, pLK44.20, which when used as a cloned probe in
Southern hybridizations of DNAs restricted with BamHI detected
polymorphisms that corresponded exactly with strain groupings
defined by mycelial compatibility. Southern hybridization of
high molecular weight DNAs separated by pulsed-field
electrophoresis showed that the repetitive element is located
on at least five to six chromosomes. Another probe, plasmid
pGP637, carrying the mitochondrial 24S rRNA gene from
Neurospora crassa, in HindIII-digested DNA, produced six
phenotypes. With the exception of phenotypic heterogeneity
within one MCG, which had three phenotypes, only one phenotype
was observed in strains from each MCG; each of four of the six
phenotypes was share


189                                  NAL Call. No.: 464.8 P56
The national biological impact assessment program.
MacKenzie, D.R.; Washington, DC
St. Paul, Minn. : American Phytopathological Society; 1991
Mar. Phytopathology v. 81 (3): p. 361; 1991 Mar.  Presented at
the "Symposium on Assessing the Socioeconomic, Ecological,and
Scientific Effects of Agricultural Biotechnology," November
16, 1988, San Diego, California.

Language:  English

Descriptors: Agriculture; Biotechnology; Genetic engineering;
Introduced species; Environmental impact; Environmental impact
reporting; Usda; Data banks; Field experimentation; Safety;
Research projects


190                                NAL Call. No.: SB732.6.M65
New pathogenicity loci in Erwinia stewartii identified by
random Tn5 mutagenesis and molecular cloning.
Coplin, D.L.; Frederick, R.D.; Majerczak, D.R.
St. Paul, Minn. : APS Press; 1992 May.
Molecular plant-microbe interactions : MPMI v. 5 (3): p.
266-268; 1992 May. Includes references.

Language:  English

Descriptors: Zea mays; Erwinia stewartii; Virulence; Genes;
Gene transfer; Genetic transformation; Plasmids; Pseudomonas
aeruginosa; Mutants; Characterization; Loci; Gene mapping;
Transposable elements; Mutagenesis; Induced mutations


191                                   NAL Call. No.: 470 SCI2
Nuclear localization of Agrobacterium VirE2 protein in plant
cells. Citovsky, V.; Zupan, J.; Warnick, D.; Zambryski, P.
Washington, D.C. : American Association for the Advancement of
Science; 1992 Jun26.
Science v. 256 (5065): p. 1802-1805; 1992 Jun26.  Includes
references.

Language:  English

Descriptors: Nicotiana tabacum; Agrobacterium; Dna;
Transgenics; Proteins

Abstract:  The Agrobacterium single-stranded DNA (ssDNA)
intermediate T-strand is likely transferred to the plant cell
nucleus as a complex with a single VirD2 molecule at its 5'
end and multiple VirE2 molecules along its length. VirD2
contains a nuclear localization signal (NLS); however, because
the T-strand is principally coated with VirE2 molecules, VirE2
also might assist in nuclear uptake. Indeed, VirE2 fused to a
reporter protein localizes to plant cell nuclei, a process
mediated by two amino acid sequences with homology to the
bipartite NLS of Xenopus nucleoplasmin. Moreover,
tumorigenicity of an avirulent virE2 mutant is restored when
inoculated on transgenic plants expressing VirE2, supporting
in planta function of VirE2.


192                                  NAL Call. No.: 448.3 J82
Nucleotide sequence and molecular characterization of pnlA,
the structural gene for damage-inducible pectin lyase of
Erwinia carotovora subsp. carotovora 71.
Chatterjee, A.; McEvoy, J.L.; Chambost, J.P.; Blasco, F.;
Chatterjee, A.K. Washington, D.C. : American Society for
Microbiology; 1991 Mar. Journal of bacteriology v. 173 (5): p.
1765-1769. ill; 1991 Mar.  Includes references.

Language:  English

Descriptors: Erwinia carotovora subsp. carotovora; Strains;
Amino acid sequences; Molecular conformation; Nucleotide
sequences; Pectate lyase; Plasmids; Restriction mapping;
Transcription; Translation

Abstract:  In a previous study, pnlA (the DNA damage-inducible
structural gene for pectin lyase) of Erwinia carotovora subsp.
carotovora 71 was localized to a 1.4-kb DNA segment within a
3.4-kb EcoRI fragment (J. L. McEvoy, H. Murata, and A. K.
Chatterjee, J. Bacteriol. 172:3284-3289, 1990). We present
here DNA sequence data for a 2.2-kb region revealing an open
reading frame of 870 bases, corresponding to a protein (Pnl)
of an approximate molecular mass of 32,100 Da and an
isoelectric point of 9.92. Although initiation of translation
is presumed to occur at the ATG codon, direct protein
sequencing revealed alanine as the N-terminal amino acid,
probably as a consequence of posttranslational removal of the
initiating amino acid. The sequence of the first 20 amino acid
residues of Pnl, purified from E. carotovora subsp. carotovora
71, agreed completely with the predicted amino acid sequence
of the N-terminal segment. This finding also indicated that
Pnl is not subject to processing by a signal peptidase. The
transcriptional start site of pnlA was determined to reside 80
bp upstream of the translational start site. Deletion analysis
revealed that 218 bp of DNA upstream of the transcriptional
start site is sufficient for induction of pnlA by mitomycin C.
Within 600 bp upstream of the translational start site, no
sequences resembling a LexA binding site (SOS box) or a cyclic
AMP receptor protein binding site were found. However,
palindromic sequences were detected at -187 and -86 bp
relative to the translational start site, and these could be
potential sites for the binding of a regulatory protein(s).
Comparison of the deduced amino acid sequence for PnlA with
that of a Pnl from Aspergillus niger and with those of various
pectate lyases of Erwinia species revealed a low degree of
homology dispersed throughout the length of the proteins.


193                                   NAL Call. No.: 500 N21P
Opine catabolism and conjugal transfer of the nopaline Ti
plasmid pTiC58 are coordinately regulated by a single
repressor.
Beck von Bodman, S.; Hayman, G.T.; Farrand, S.K.
Washington, D.C. : The Academy; 1992 Jan15.
Proceedings of the National Academy of Sciences of the United
States of America v. 89 (2): p. 643-647. ill; 1992 Jan15. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Amino acid sequences;
Regulation; Mutants; Nopaline; Nucleotide sequences; Plasmids;
Strains; Transcription

Abstract:  The Ti plasmids of Agrobacterium tumefaciens are
conjugal elements whose transfer is strongly repressed.
Transfer is induced by the conjugal opines, a group of unique
carbon compounds synthesized in crown gall tumors. The opines
also induce Ti plasmid-encoded genes required by the bacteria
for opine catabolism. We have cloned and sequenced a gene from
the Ti plasmid pTiC58, whose product mediates the opine-
dependent regulation of conjugal transfer and catabolism of
the conjugal opines, agrocinopines A and B. The gene, accR, is
closely linked to the agrocinopine catabolic locus. A
spontaneous mutant Ti plasmid, pTiC58Tra(c), which
constitutively expresses conjugal transfer and opine
catabolism, was complemented in trans by a clone of wild-type
accR. Comparative sequence analysis identified a 5-base-pair
deletion close to the 5' end of the mutant accR allele from
pTiC58Tra(c). Analysis of lacZ fusions in conjugal transfer
and opine catabolic structural genes demonstrated that the
accR-encoded function is a transcriptional repressor. accR can
encode a 28-kDa protein. This protein is related to a class of
repressor proteins that includes LacR, GutR, DeoR, FucR, and
GlpR that regulate sugar catabolic systems in several
bacterial genera.


194                                  NAL Call. No.: 448.3 J82
Opine transport genes in the octopine (occ) and nopaline (noc)
catabolic regions in Ti plasmids of Agrobacterium tumefaciens.
Zanker, H.; Lintig, J. von; Schroder, J.
Washington, D.C. : American Society for Microbiology; 1992
Feb. Journal of bacteriology v. 174 (3): p. 841-849; 1992 Feb. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Genes; Octopine;
Nopaline; Plasmids; Catabolism; Nucleotide sequences; Amino
acid sequences

Abstract:  The occ and noc regions of octopine and nopaline Ti
plasmids in Agrobacterium tumefaciens are responsible for the
catabolic utilization of octopine and nopaline, respectively.
Opine-inducible promoters, genes for regulatory proteins and
for catabolic enzymes, had been identified in previous work.
However, both regions contained additional DNA stretches which
were under the control of opine-inducible promoters, but the
functions were unknown. We investigated these stretches by DNA
sequence and functional analyses. The sequences showed that
both of the catabolic regions contain a set of four genes
which are transcribed in the same direction. The occ and noc
region genes are related, but the arrangement of the genes is
different. The deduced polypeptides are related to those of
binding protein-dependent transport systems of basic amino
acids in other bacteria. The comparison suggested that three
of the polypeptides are located in the membrane and that one
is a periplasmic protein. We constructed cassettes which
contained either the putative transport genes only or the
complete occ or noc region; all constructs, however, included
the elements necessary for opine-induced expression of the
genes (the regulatory gene and the inducible promoters).
Uptake studies with 3H-labelled octopine showed that the
putative transport genes in the occ region code for octopine
uptake proteins. The corresponding studies with 3H-labelled
nopaline and the noc region cassettes indicated that the
uptake of nopaline requires the putative transport genes and
additional functions from the left part of the noc region.


195                                  NAL Call. No.: 448.3 J82
Organization and environmental regulation of the Pseudomonas
syringae pv. syringae 61 hrp cluster.
Xiao, Y.; Lu, Y.; Heu, S.; Hutcheson, S.W.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Journal of bacteriology v. 174 (6): p. 1734-1741; 1992
Mar.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. syringae; Genes; Gene
expression; Genetic regulation; Infection; Amino acids;
Pathogenicity; Host specificity

Abstract:  The ability of Pseudomonas syringae pv. syringae 61
to elicit the hypersensitive response in nonhost plant species
has been linked to a cluster of hrp/hrm genes whose expression
appears to be environmentally regulated. To understand the
genetic organization of this hrp/hrm gene cluster and its
expression during the interaction with nonhost plant species
better, we constructed a set of chromosomal hrp-uidA fusions
in P. syringae pv. syringae 61 by Tn5-gusA1 mutagenesis of the
cloned hrp/hrm gene cluster and transferred them into the
genome by marker exchange mutagenesis. Complementation
analysis employing plasmid-borne Tn5-gusA1 insertions and
previously characterized chromosomal TnphoA mutations defined
at least eight apparent transcriptional units within the
hrp/hrm cluster, several of which were multicistronic. The
expression of hrp-uidA fusions in seven of these apparent hrp
transcriptional units increased following inoculation into
tobacco leaves. Enhanced expression from a representative
fusion was detected 1 h after inoculation of tobacco leaves.
The induction observed in planta was similar to the levels
detected following culture of the bacteria in minimal-salts
medium: irrespective of the carbon source. Complex amino acid
sources, such as peptone, repressed the expression of P.
syringae pv. syringae 61 hrp genes at levels exceeding 0.028%.
The results indicate that enhanced expression of hrp genes
occurs early in the interaction with nonhost plant species in
an apparent response to altered nutritional conditions.


196                                  NAL Call. No.: QH426.P56
Organization of the agropine synthesis region of the T-DNA of
the Ri plasmid from Agrobacterium rhizogenes.
Bouchez, D.; Tourneur, J.
Orlando, Fla. : Academic Press; 1991 Jan.
Plasmid v. 25 (1): p. 27-39; 1991 Jan.  Includes references.

Language:  English

Descriptors: Agrobacterium rhizogenes; Plasmids; Dna; Amino
acid derivatives; Amino acid metabolism; Nucleotide sequences;
Genes; Molecular mapping; Ligases; Amino acid sequences

Abstract:  The agropine/mannopine synthesis region of the TR
region of the Ri plasmid of Agrobacterium rhizogenes strain A4
was localized on the basis of sequence similarity with probes
from Ti plasmids of Agrobacterium tumefaciens and analysis of
transposon insertions. The nucleotide sequence of the right
part of the TR-DNA of pRiA4, encompassing the three genes
involved in mannityl-opine synthesis, was determined and
compared to the sequence of the corresponding region of the
octopine-type Ti plasmid pTi15955. The organization of this
region is strongly conserved between Ri and Ti plasmids, but
the similarity is restricted to the coding sequences: no
homology was detected in the 5'and 3' flanking sequences. The
mas1' and ags proteins are the most conserved, showing more
than 68% amino acid conservation, whereas the mas2' proteins
are only 59% identical. Significant G/C content and codon
usage differences are observed between pTi15955 and pRiA4. An
open reading frame strongly similar to that of bacterial
repressors is situated immediately to the right of the TR
region.


197                                  NAL Call. No.: 448.3 J82
The osa gene of pSa encodes a 21.1-kilodalton protein that
suppresses Agrobacterium tumefaciens oncogenicity.
Close, S.M.; Kado, C.I.
Washington, D.C. : American Society for Microbiology; 1991
Sep. Journal of bacteriology v. 173 (17): p. 5449-5456; 1991
Sep.  Includes references.

Language:  English

Descriptors: Datura stramonium; Agrobacterium tumefaciens;
Genes; Bacterial proteins; Plasmids; Nucleotide sequences;
Amino acid sequences; Gene mapping; Virulence; Inhibition;
Tumors; Crown gall; Stems

Abstract:  The incompatibility group W plasmid pSa suppresses
Agrobacterium tumefaciens oncogenicity (J. Loper and C. Kado,
J. Bacteriol. 139:591-596, 1979). The oncogenic suppressive
activity was localized to a 3.1-kb region of pSa by Tn5
mutagenesis and deletion analysis. Within this fragment, a
1.1-kb subclone bearing oncogenic suppressive activity was
subjected to further characterization. Nucleotide sequencing
of the 1.1-kb fragment revealed a 570-bp open reading frame
(ORF1) that has a coding capacity for a protein of 21.1 kDa.
Sequencing of flanking regions revealed a second ORF (ORF2)
located 3 bp upstream of ORF1, with a coding capacity for a
protein of 22.8 kDa. Gene fusions of these ORFs to a T7(phi)10
expression system in Escherichia coli resulted in the
synthesis of polypeptides of the predicted sizes. An E. coli
promoter consensus sequence was not found in the expected
positions in the region preceding ORF1. However, several
sequences with similarity to the consensus -10 sequence of the
A. tumefaciens vir gene promoters were found upstream of ORF1.
Potential translational start signals are upstream of ORF1 and
ORF2. These sequences showed no significant similarity at the
nucleotide or amino acid levels with those in available data
bases. However, the C-terminal portion of the ORF1 protein is
rich in hydrophobic residues. Perhaps oncogenicity suppression
is effected by an association of this protein with the
Agrobacterium membrane such that T-DNA transfer is blocked.


198                                   NAL Call. No.: QH426.C8
Parasexual cycle and genetic analysis following protoplast
fusion in Nectria haematococca.
Daboussi, M.J.; Gerlinger, C.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (4/5): p. 385-392; 1992.  Includes
references.

Language:  English

Descriptors: Nectria haematococca; Protoplast fusion; Genetic
transformation; Parasexuality; Heteroploidy; Heterokaryosis;
Haploids; Segregation; Linkage; Mitotic recombination;
Recombination; Crossing over

Abstract:  Protoplasts of multiauxotrophic strains of Nectria
haematococca (the perfect form of Fusarium solani) were fused
and grown on different selective media. Following protoplast
fusion, rapidly growing heterokaryons were formed at high
frequency (about 1%). By collecting uninucleate microconidia
from these heterokaryons, it was possible to isolate a few
colonies with new combinations of the parental markers. On
some selective media, non-heterokaryotic fusion products,
easily distinguishable from heterokaryons by their growth
characteristics, were detected at low frequency. These
colonies were either stable haploid recombinants or unstable
'hybrids' of unknown ploidy. Genetic analysis of 'hybrids' in
which six factors were heterozygous provided evidence for
nuclear fusion events. These 'hybrid' colonies spontaneously
segregated a large number of haploid recombinants, allowing
the analysis of linkage relationships between markers. The
detection of a mitotic linkage between two markers which
appeared unlinked following meiosis, demonstrates that mitotic
mapping may be an important complement to meiotic analysis for
mapping the chromosomes of Nectria haematococca.


199                                    NAL Call. No.: QK1.B38
The parasexual cycle in Ustilago scabiosae (Ustilaginales).
Garber, E.D.; Ruddat, M.
Chicago, Ill. : University of Chicago Press; 1992 Mar.
International journal of plant sciences v. 153 (1): p. 98-101;
1992 Mar. Includes references.

Language:  English

Descriptors: Ustilago; Ustilago violacea; Parasexuality;
Fungal spores; Color; Phenotypes; Diploidy; Recombination;
Haploidy; Haploids; Induced mutations; Genetic markers;
Mating; Alleles


200                                 NAL Call. No.: SB327.A1B5
Parental effects on performance of common bacterial blight
resistant and susceptible selections of common bean.
Maharaj, P.; Michaels, T.E.
Fort Collins, Colo : Howard F. Schwartz, Colorado State
University; 1992. Annual report of the Bean Improvement
Cooperative v. 35: p. 84-85; 1992. Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Phaseolus acutifolius;
Xanthomonas campestris pv. phaseoli; Disease resistance; Plant
breeding; Gene transfer; Lines


201                                  NAL Call. No.: 464.8 P56
A pathogenicity locus from Xanthomonas citri enables strains
from several pathovars of X. campestris to elicit cankerlike
lesions on citrus. Swarup, S.; De Feyter, R.; Brlansky, R.H.;
Gabriel, D.W.
St. Paul, Minn. : American Phytopathological Society; 1991
Jul. Phytopathology v. 81 (7): p. 802-809; 1991 Jul.  Includes
references.

Language:  English

Descriptors: Citrus paradisi; Xanthomonas campestris pv.
citri; Pathotypes; Virulence; Genes; Loci; Dna libraries;
Screening; Clones; Plasmids; Xanthomonas; Strains; Strain
differences; Insertional mutagenesis; Phenotypes; Lesions;
Host range

Abstract:  A virulence enhancement approach was used to clone
a pathogenicity (pth) locus from a highly virulent pathogen by
assaying the library in a second, less virulent strain that
was compatible with the same host. A genomic library of the
virulent Asiatic canker pathogen Xanthomonas citri was
conjugally transferred to the opportunistic pathogen, X.
campestris citrumelo, and the transconjugants were screened on
Citrus paradisi 'Duncan' (grapefruit) leaves. Transconjugants
able to induce host cell proliferation and raised, Asiatic
cankerlike lesions were identified, and clone pSS10.35 was
found to carry the gene(s) responsible. This clone was
transferred to other Xanthomonas strains, including two that
are weakly pathogenic to citrus in greenhouse tests (members
of X. c. alfalfae and X. c. cyamopsidis) and two that are
avirulent on citrus (X. phaseoli and X. c. malvacearum).
Transconjugants of the two weakly pathogenic Xanthomonas
strains induced cankerlike lesions when inoculated on citrus;
these same strains became avirulent on their homologous host
plants. Transconjugants of X. phaseoli and X. c. malvacearum
strains remained unaltered in phenotype on citrus. A 3.7-kb
region of pSS10.35 carrying the pthA locus was identified by
subcloning and Tn5-gusA mutagenesis. Marker-exchange
mutagenesis of X. citri using Tn5-gusA insertions in the 3.7-
kb region resulted in a complete loss of virulence (disease
symptoms and growth in planta) on citrus and loss of the
hypersensitive response on heterologous hosts (i.e., an Hrp-
phenotype). The Hrp- phenotype, but not growth in planta, of
the marker-exchanged mutants was restored by subclones of
pSS10.35 containing the 3.7-kb region.


202                                NAL Call. No.: SB732.6.M65
A pathogen-induced wheat gene encodes a protein homologous to
glutathione-S-transferases.
Dudler, R.; Hertig, C.; Rebmann, G.; Bull, J.; Mauch, F.
St. Paul, Minn. : APS Press; 1991 Jan.
Molecular plant-microbe interactions : MPMI v. 4 (1): p.
14-18; 1991 Jan. Includes references.

Language:  English

Descriptors: Triticum aestivum; Disease resistance; Genetic
resistance; Erysiphe graminis; Strains; Strain differences;
Pathogenicity; Induced resistance; Genes; Defense mechanisms;
Genetic regulation; Glutathione transferase; Nucleotide
sequences; Amino acid sequences; Genetic analysis; Exons;
Introns


203                                 NAL Call. No.: QH442.G456
PCR increasingly employed in agricultural and veterinary
biotechnology. Fox, S.
New York, N.Y. : Mary Ann Liebert; 1992 Jun01.
Genetic engineering news v. 12 (9): p. 6, 7, 9; 1992 Jun01.

Language:  English

Descriptors: Polymerase chain reaction; Plant pests; Plant
pathogens; Plant diseases; Animal diseases; Diagnosis; Genetic
engineering; Plant breeding; Animal breeding; Biotechnology


204                                  NAL Call. No.: 450 J8224
Phenotypic effects of isolated pRiA4 TL-DNA rol genes in the
presence of intact TR-DNA in transgenic plants of Solanum
dulcamara L. McInnes, E.; Morgan, A.J.; Mulligan, B.J.; Davey,
M.R.
Oxford : Oxford University Press; 1991 Oct.
Journal of experimental botany v. 42 (243): p. 1279-1286; 1991
Oct.  Includes references.

Language:  English

Descriptors: Solanum dulcamara; Agrobacterium rhizogenes;
Plant diseases; Genetic transformation; Transgenics; Genes;
Plasmids; Roots; Phenotypes; Leaves; Plant morphology; Growth
rate; Epinasty; Amino acid derivatives

Abstract:  The effect of the rol genes, together with the TR-
DNA of pRiA4 on the phenotype of Solanum dulcamara plants, was
analysed. Plants transformed by Agrobacterium strain
BN1010::rolA (rolA+TR+) exhibited severe leaf wrinkling,
whereas plants transformed by strain BN1010::rolC (rolC+TR+)
had a typical 'hairy root' phenotype. Leaf discs excised from
these latter plants produced roots on hormone-free medium.
BN1010::rolABC (rolABC+TR+) transformed plants had an
exaggerated transformed phenotype. Some of the BN1010::rolABC
transformants had positively geotropic root growth which
correlated with the presence of multiple copies of the TR-DNA.
S. dulcamara plants, transformed by the TR-DNA region only,
exhibited epinasty. Scanning electron microscopy of plants
containing various regions of agropine Ri T-DNA revealed that
transformation causes changes in basic plant structure.


205                                 NAL Call. No.: QK725.P532
Phenylpropanoid pathway intermediates regulate transient
expression of a chalcone synthase gene promoter.
Loake, G.J.; Choudhary, A.D.; Harrison, M.J.; Mavandad, M.;
Lamb, C.J.; Dixon, R.A.
Rockville, Md. : American Society of Plant Physiologists; 1991
Aug. The Plant cell v. 3 (8): p. 829-840; 1991 Aug.  Includes
references.

Language:  English

Descriptors: Phaseolus vulgaris; Medicago sativa;
Colletotrichum lindemuthianum; Promoters; Naringenin-chalcone
synthase; Chloramphenicol acetyltransferase; Reporter genes;
Chimeras; Gene expression; Transcription; Genetic regulation;
Cinnamic acid; P-coumaric acid; Carbohydrates; Cell wall
components; Hyphae; Deletions; Genetic transformation;
Protoplasts; Electroporation

Abstract:  A chimeric gene construct containing a bean
chalcone synthase (CHS) promoter fused to the chloramphenicol
acetyltransferase (CAT) reporter gene was strongly expressed
when electroporated into alfalfa protoplasts that were then
exposed to a fungal elicitor. Low concentrations (5 X 10(-6)
to 10(-4) M) of exogenously applied transcinnamic acid (CA),
the first intermediate of the phenylpropanoid pathway,
slightly stimulated elicitor-induced CAT expression, whereas
high concentrations (>1O(-4) M) severely reduced expression to
below the levels observed in the absence of elicitor. In
contrast, trans-p-coumaric acid (4-CA, the second intermediate
in the pathway) stimulated expression from the CHS promoter up
to 4.5-fold at 5 X 10(-4) M. Expression of CAT driven by the
promoters of other elicitor-inducible defense response genes
was not markedly affected by CA or 4-CA. Stimulation of CHS
promoter expression by low concentrations of CA and 4-CA was
completely abolished by 5' deletion to position -130, but not
-174. When the -180 to -130 region of the CHS15 promoter was
coelectroporated into elicited protoplasts on a separate
plasmid along with the intact -326 CHS-CAT construct, the
decreased CAT expression as a function of CA or 4-CA
concentration was consistent with the coelectroporated
sequence competing in trans with the intact promoter for the
binding of a factor(s) involved in the up regulation of CHS
transcription by 4-CA and low concentrations of CA. Our data
support the hypothesis that phenylpropanoid compounds may act
as natural and specific regulators of plant gene expression
and define the location of a cis-acting element in the CHS15
promoter involved in the induction by phenylpropanoid pathway
intermediates.


206                                  NAL Call. No.: 448.3 J82
Phylogenetic analysis and evolution of RNase P RNA in
proteobacteria. Brown, J.W.; Haas, E.S.; James, B.D.; Hunt,
D.A.; Pace, N.R. Washington, D.C. : American Society for
Microbiology; 1991 Jun. Journal of bacteriology v. 173 (12):
p. 3855-3863; 1991 Jun.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Alcaligenes;
Desulfovibrio desulfuricans; Firmicutes; Gram negative
bacteria; Phylogeny; Genes; Rna; Ribonucleases; Nucleotide
sequences; Cloning; Molecular conformation

Abstract:  The secondary structures of the eubacterial RNase P
RNAs are being elucidated by a phylogenetic comparative
approach. Sequences of genes encoding RNase P RNA from each of
the recognized subgroups (alpha, beta, gamma, and delta) of
the proteobacteria have now been determined. These sequences
allow the refinement, to nearly the base pair level, of the
phylogenetic model for RNase P RNA secondary structure.
Evolutionary change among the RNase P RNAs was found to occur
primarily in four discrete structural domains that are
peripheral to a highly conserved core structure. The new
sequences were used to examine critically the proposed
similarity (C. Guerrier-Takada, N. Lumelsky, and S. Altman,
Science 246:1578-1584, 1989) between a portion of RNase P RNA
and the "exit site" of the 23S rRNA of Escherichia coli.
Phylogenetic comparisons indicate that these sequences are not
homologous and that any similarity in the structures is, at
best, tenuous.


207                                  NAL Call. No.: 448.3 J82
Physical and functional characterization of the gene cluster
encoding the polyketide phytotoxin coronatine in Pseudomonas
syringae pv. glycinea. Young, S.A.; Park, S.K.; Rodgers, C.;
Mitchell, R.E.; Bender, C.L. Washington, D.C. : American
Society for Microbiology; 1992 Mar. Journal of bacteriology v.
174 (6): p. 1837-1843; 1992 Mar.  Includes references.

Language:  English

Descriptors: Pseudomonas syringae pv. glycinea; Phytotoxins;
Genes; Plasmids; Biosynthesis; Mutations

Abstract:  Pseudomonas syringae pv. glycinea PG4180 produces
the polyketide phytotoxin coronatine. The coronatine synthesis
genes in PG4180 were previously shown to reside on a 90-kb
plasmid designated p4180A. In the present study, clones
containing a 34-kb region of p4180A were saturated with Tn5,
and 71 unique mutations were recombined into p4180A by marker
exchange. The effect of each mutation on coronatine synthesis
was determined by analyzing the organic acids produced by the
mutants by reverse-phase high-performance liquid
chromatography. The organic acids of selected mutants were
derivatized to their methyl esters and analyzed by gas
chromatography and gas chromatography-mass spectrometry.
Mutations in a 20.5-kb region of p4180A completely blocked the
synthesis of coronafacic acid and coronatine. Mutations within
a 4.4-kb region of p4180A prevented the formation of
coronatine but allowed for production of coronafacic acid,
coronafacoyl-valine, coronafacoylisoleucine, and
coronafacoylalloisoleucine. The phenotypes of selected mutants
were further confirmed in feeding experiments in which
coronafacic acid or coronamic acid was added to the culture
media. The results of this study allow us to speculate on the
likely sequence of steps in the later stages of coronatine
biosynthesis.


208                                   NAL Call. No.: 450 P692
Physical, chemical, developmental, and genetic factors that
modulate the Agrobacterium-Vitis interaction.
Lowe, B.A.; Krul, W.R.
Rockville, Md. : American Society of Plant Physiologists; 1991
May. Plant physiology v. 96 (1): p. 121-129; 1991 May. 
Includes references.

Language:  English

Descriptors: Vitis rupestris; Vitis; Agrobacterium
tumefaciens; Tumors; Pathogenicity; Genetic regulation;
Genetic resistance; Host parasite relationships;
Compatibility; Genetic transformation; Light relations;
Auxins; Genotypes; Hybrids; Host range; Necrosis; Phenotypes;
Cultivars

Abstract:  Tumor formation in Vitis species and hybrids,
incited by Agrobacterium tumefaciens, was altered by chemical,
physical, developmental, and genetic variables. Knowledge of
the effect of these variables was used to develop a stringent
in vitro assay system to select parents for a study of genetic
factors that modulate tumor formation. Tumor formation was
reduced by short day preconditioning of assay plants and by
inoculation of the morphological apex of isolated stem
segments. Pretreatment of plants with auxin or cytokinin
altered specificity in various combinations of strains and
host genotypes. All Vitis species and hybrids formed tumors in
response to strains designated as limited host range, but some
displayed a necrotic reaction (cell death at and below site of
inoculation) or a null response (same as the response to
inoculation with an avirulent strain) to strains designated as
wide host range (VC Knauf, CG Panagopoulos, EW Nester [1982)
Phytopathology 72: 1545-1549). Screens of F1 progeny, derived
from crosses of null, necrotic, and tumor-producing
phenotypes, demonstrated that the null and the necrotic
phenotypes were modulated by dominant and recessive host
genes. The extent of cellular necrosis in the necrotic
phenotype was modified by the morphological location of the
inoculation site, by the presence of buds on the host stem,
and by deletion of the tryptophane monooxygenase locus gene of
the Ti-plasmid.


209                                   NAL Call. No.: Q320.B56
Planned introductions in biological control.
Ehler, L.E.
Stoneham, Mass. : Butterworth Publishers; 1991.
Biotechnology (15): p. 21-39; 1991.  In the Series Analytic:
Assessing Ecological Risks of Biotechnology / edited by Lev R.
Ginzburg.  Includes references.

Language:  English

Descriptors: Biological control agents; Introduction; Plant
protection; Release techniques; Environmental impact;
Biotechnology; Transgenics; Ecological balance


210                                 NAL Call. No.: 442.8 AN72
Plant resistance to fungal diseases induced by the infection
of cucumber mosaic virus attenuated by satellite RNA.
Qin, B.; Zhang, X.; Wu, G.; Tien, P.
Warwick : Association of Applied Biologists; 1992 Feb.
Annals of applied biology v. 120 (2): p. 361-366; 1992 Feb. 
Includes references.

Language:  English

Descriptors: Cucumis sativus; Nicotiana tabacum; Lycopersicon
esculentum; Pseudoperonospora cubensis; Fulvia fulva;
Alternaria longipes; Fungal diseases; Cucumber mosaic
cucumovirus; Rna; Attenuation; Biological control agents;
Disease resistance; Transgenics; Infection; Symptoms; Field
tests; Tests


211                                  NAL Call. No.: 464.8 P56
Plasmid DNA fingerprints distinguish pathotypes of Xanthomonas
campestris pv. citri, the causal agent of citrus bacterial
canker disease. Pruvost, O.; Hartung, J.S.; Civerolo, E.L.;
Dubois, C.; Perrier, X. St. Paul, Minn. : American
Phytopathological Society; 1992 Apr. Phytopathology v. 82 (4):
p. 485-490; 1992 Apr.  Includes references.

Language:  English

Descriptors: Citrus; Xanthomonas campestris pv. citri;
Pathotypes; Genetic analysis; Dna; Plasmids; Dna
fingerprinting; Strains; Identification; Strain differences;
Characterization; Genetic variation

Abstract:  Plasmid DNA was isolated from 54 strains of
Xanthomonas campestris pv. citri, associated with different
forms of citrus bacterial canker disease (CBCD). The number of
plasmids per strain varied from one to five. A total of 24
plasmid bands with sizes from 7 to 100 kilobases (kb) were
identified. Strains that had identical plasmid profiles were
generally associated with the same form of CBCD. After
digesting the plasmid DNA with each of three restriction
endonucleases, 87 fragments with different sizes from about 1
to 30 kb were visualized. Strains belonging to a specific CBCD
group shared plasmid DNA fragments of similar sizes.
Dendrograms derived from plasmid DNA fingerprint analyses
allowed us to clearly distinguish A, B, and C pathotypes of X.
c. citri. The strain Xc90, associated with bacteriosis of
Mexican lime in Mexico (CBCD-D) was not clearly
distinguishable from strains associated with cancrosis B
(CBCD-B) from Argentina and Uruguay. Plasmid DNA fragments
specifically associated with some groups of strains were
identified. A BamHI fragment from a CBCD-A strain was used as
a hybridization probe. A strong signal was recorded in all
CBCD-A strains studied. Weaker hybridization signals were
observed with one or two high molecular weight bands in all
CBCD-B strains studied. All three type C strains had a band of
slightly smaller size than the probe, but which hybridized
only very weakly. Strain Xc70 also had a homologous larger
band similar in size to one found in the CBCD-B strains.
Hierarchical cluster analysis of the RFLP data from the
plasmid DNA revealed phenetic clusters strikingly similar to
those obtained previously from analysis of genomic DNA,
lending support to the concept of balanced co-evolution of
plasmid and chromosomal genomes.


212                                  NAL Call. No.: 464.8 P56
Plasmid, genomic, and bacteriocin diversity in U.S. strains of
Xanthomonas campestris pv. oryzae.
Xu, G.W.; Gonzalez, C.F.
St. Paul, Minn. : American Phytopathological Society; 1991
Jun. Phytopathology v. 81 (6): p. 628-631; 1991 Jun.  Includes
references.

Language:  English

Descriptors: Oryza sativa; Xanthomonas campestris pv. oryzae;
Strains; Strain differences; Characterization; Plasmids; Dna;
Genome analysis; Bacteriocins; Diversity; Plant pathogenic
bacteria

Abstract:  Twenty-six strains of Xanthomonas campestris pv.
oryzae isolated during a recent outbreak of bacterial leaf
blight of rice in the United States were analyzed for their
plasmid, genome, and bacteriocin diversity. Twenty of the
strains harbored indigenous plasmid(s) and could be divided
into three distinct groups. Restriction fragment length
polymorphism (RFLP) analyses of genomic DNA revealed
hybridization profiles that separated the strains into four
groups. Four bacteriocin groups were identified among the
strains tested. Five subgroups were identified based on
plasmid content, RFLP analyses, and bacteriocin typing.


213                                  NAL Call. No.: 448.3 J82
Polygalacturonase is a virulence factor in Agrobacterium
tumefaciens biovar 3. Rodriguez-Palenzuela, P.; Burr, T.J.;
Collmer, A.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Journal of bacteriology v. 173 (20): p. 6547-6552; 1991
Oct.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Strains;
Polygalacturonase; Genes; Clones; Virulence; Host specificity;
Vitis vinifera

Abstract:  Agrobacterium tumefaciens biovar 3 causes both
crown gall and root decay of grapes. All biovar 3 strains,
regardless of their tumorigenicity, produce in culture a
single polygalacturonase with a pI around 4.5. A. tumefaciens
biovar 3 strain CG49 was mutagenized with Tn5 by using
pSUP2021 as a suicide vector. A mutant strain, CG50, lacking
polygalacturonase activity was isolated. The mutation was due
to a single Tn5 insertion in an 8.5-kb EcoRI fragment that
also contained the polygalacturonase structural gene. The
polygalacturonase-encoding pehA gene was cloned in Escherichia
coli by using the plasmid pBluescript as a vector. Activity-
stained isoelectric focusing gel analysis demonstrated that E.
coli cells harboring the pehA+ recombinant plasmid pCPP2067
produced a polygalacturonase in culture with the same pI as
the enzyme produced by CG49. The peha gene was localized
within a 2.5-kb HindIII-salI fragment. This fragment was used
as a probe in Southern hybridization analysis and showed that
no closely related genes are present in A. tumefaciens biovars
1 or 2, Rhizobium leguminosarum, or Bradyrhizobium japonicum.
The polygalacturonase mutant was unable to induce root decay
in grapes (Vitis vinifera cv. Chardonnay) and was
substantially less tumorigenic than the wild type in grape
stems when low levels of inoculum were used, although both
strains were equally tumorigenic in potato disc assays. The
results indicate that polygalacturonase is a virulence factor
in both the root decay and crown gall incited in grapes by A.
tumefaciens biovar 3.


214                                  NAL Call. No.: 448.3 AP5
Polygalacturonase production by Agrobacterium tumefaciens
biovar 3. McGuire, R.G.; Rodriguez-Palenzuela, P.; Collmer,
A.; Burr, T.J. Washington, D.C. : American Society for
Microbiology; 1991 Mar. Applied and environmental microbiology
v. 57 (3): p. 660-664; 1991 Mar. Includes references.

Language:  English

Descriptors: Vitis; Agrobacterium tumefaciens; Strains;
Polygalacturonase; Plasmids; Pathogens

Abstract:  Agrobacterium tumefaciens biovar 3 causes both
crown gall and root decay of grape. Twenty-two Agrobacterium
strains representing biovars 1, 2, and 3 were analyzed for
tumorigenicity, presence of a Ti plasmid, ability to cause
grape seedling root decay, and pectolytic activity. All of the
biovar 3 strains, regardless of their tumorigenicity or
presence of a Ti plasmid, caused root decay and were
pectolytic, whereas none of the biovar 1 and 2 strains had
these capacities. Isoelectrically focused gels that were
activity stained with differentially buffered
polygalacturonate-agarose overlays revealed that all of the
biovar 3 strains produced a single polygalacturonase with a pH
optimum of 4.5 and pIs ranging from 4.8 to 5.2. The enzyme was
largely extracellular and was produced constitutively in basal
medium supplemented with a variety of carbon sources including
polygalacturonic acid. Lesions on grape seedling roots
inoculated with A. tumefaciens biovar 3 strain CG49 yielded
polygalacturonase activity with a pI similar to that of the
enzyme produced by the bacterium in culture. These
observations support the hypothesis that the polygalacturonase
produced by A. tumefaciens biovar 3 has a role in grape root
decay.


215                                  NAL Call. No.: QH426.P56
Polymorphism of nopaline-type T-DNAs from Agrobacterium
tumefaciens. Wabiko, H.; Kagaya, M.; Sano, H.
Orlando, Fla. : Academic Press; 1991 Jan.
Plasmid v. 25 (1): p. 3-15; 1991 Jan.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Dna;
Restriction mapping; Restriction fragment length polymorphism;
Amino acid derivatives; Strain differences; Molecular mapping;
Pathogenicity; Tumors; Crown gall; Petunia; Populus; Populus
grandidentata

Abstract:  The structure of several T-DNAs of agrobacterium
tumefaciens was determined by molecular cloning and Southern
hybridization. The T-DNAs cloned in Escherichia coli vectors
from four different nopaline type strains (PyTE1, PO31, PO22,
and AKE10) showed various sizes of restriction enzyme
fragments. Comparative analysis of the restriction maps
revealed that the T-DNAs were composed of three distinct
structural domains: (1) the region proximal to the right
border (Domain I) containing the portion essential for
tumorigenicity, (2) the proximity to the left border (Domain
II), and (3) the region between the two domains (Domain III)
to both of which no functional assignments have yet been made.
The restriction map indicated that the Domains I and II were
conserved in the most clones, including the well-characterized
T37 T-DNA. The only exception was AKK1 (obtained from AKE10)
which differed in Domain I. In the Domain III, insertions of
1.5- or 1.6-kb DNA were found in four clones, whereas an
additional 2.5-kb insertion was found in one clone (PO22P1).
The individual T-DNAs including Domain III with insertions was
demonstrated in petunia and poplar tumors induced by the
referred A. tumefaciens strains. However, resulting tumors
differed in morphology and growth. These results suggest that
the length polymorphism of the nopaline type T-DNA can be
accounted by DNA insertions, and that diverse T-DNAs reflect
their different roles in tumorigenicity.


216                                  NAL Call. No.: QH301.A43
Positive regulation of the expression of the virD locus of the
nopaline-type Ti-plasmid C58 of Agrobacterium tumefaciens.
Li, K.G.; Andrianov, V.M.; Piruzyan, E.S.
New York, N.Y. : Consultants Bureau; 1991 Mar.
Biology bulletin of the Academy of Sciences of the USSR v. 17
(3): p. 211-214. ill; 1991 Mar.  Translated from: Izvestiia
Akademii Nauk SSSR, Seriia Biologicheskaia, v. 17 (3), 1990,
p. 325-328. (511 SA2B).  Includes references.

Language:  English; Russian

Descriptors: Agrobacterium tumefaciens; Crown gall; Gene
expression; Gene mapping; Genetic regulation; Loci; Molecular
weight; Nopaline; Plasmids; Promoters; Soil bacteria;
Escherichia coli


217                                NAL Call. No.: SB732.6.M65
Positive regulators of opine-inducible promoters in the
nopaline and octopine catabolism regions of Ti plasmids.
Lintig, J. von; Zanker, H.; Schroder, J.
St. Paul, Minn. : APS Press; 1991 Jul.
Molecular plant-microbe interactions : MPMI v. 4 (4): p.
370-378; 1991 Jul. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Tumors;
Genetic regulation; Genes; Catabolism; Nopaline; Octopine;
Transcription; Promoters; Nucleotide sequences; Genetic
analysis; Molecular genetics


218                               NAL Call. No.: SB950.2.I3I4
The potential for bioengineering in disease control.
Farrand, S.
Urbana, Ill. : Cooperative Extension Service, Univ of Illinois
at Urbana-Champaign; 1991.
Illinois Agricultural Pesticides Conference summaries of
presentations January 8, 9, 10, 1991, Urbana, Illinois / Univ
of Illinois at Urbana-Champaign, Coop Ext Serv, in coop with
the Illinois Natural History Survey. p. 88-92; 1991.
"Proceedings of the 1991 Illinois Agricultural Pesticides
Conference," January 8-10, 1991, Urbana, Illinois.

Language:  English

Descriptors: Crop management; Disease control; Plant breeding


219                                  NAL Call. No.: QH506.E46
The protein encoded by the rolB plant oncogene hydrolyses
indole glucosides. Estruch, J.J.; Schell, J.; Spena, A.
Oxford, Eng. : IRL Press; 1991 Nov.
The EMBO journal - European Molecular Biology Organization v.
10 (11): p. 3125-3128; 1991 Nov.  Includes references.

Language:  English

Descriptors: Agrobacterium rhizogenes; Oncogenes; Beta-
glucosidase; Glucosides; Hydrolysis

Abstract:  The rolB gene of Agrobacterium rhizogenes, whose
expression stimulates the formation of roots by transformed
plant tissues and other growth alterations in transgenic
plants, codes for a beta-glucosidase able to hydrolyse indole-
beta-glucosides. indeed, we show that extracts of bacteria
and/or plant tissue expressing the rolB protein hydrolyse
indoxyl-beta-glucoside (plant indican). Because of the
structural similarity between indoxyl-beta-glucoside and
indole-3-acetyl-beta-glucoside (IAA-beta-glucoside), we
propose that the physiological and developmental alterations
in transgenic plants expressing the rolB gene could be the
result of an increased intracellular auxin activity caused by
the release of active auxins from inactive beta-glucosides.
Thus two of the oncogenes carried by the T-DNA of the plant
pathogen Agrobacterium rhizogenes (rolB and rolC) perturb
plant growth and development by coding for beta-glucosidases
with distinct specificities. Whereas the rolC beta-glucosidase
releases cytokinins from their glucoside conjugates, the rolB
encoded protein hydrolyses indole-glucosides. The combined
action of these two genes therefore is expected to modulate
the intracellular concentration of two of the main growth
factors active in plants.


220                                  NAL Call. No.: 448.3 AP5
Pseudomonas stutzeri YPL-1 genetic transformation and
antifungal mechanism against Fusarium solani, an agent of
plant root rot.
Lim, H.S.; Kim, Y.S.; Kim, S.D.
Washington, D.C. : American Society for Microbiology; 1991
Feb. Applied and environmental microbiology v. 57 (2): p.
510-516. ill; 1991 Feb. Includes references.

Language:  English

Descriptors: Fusarium solani; Root rots; Pseudomonas; Strains;
Genetic transformation; Enzymes; Lysis; Mycelium; Growth;
Biological control agents; Microbial pesticides

Abstract:  An actively antagonistic bacterium that could be
used as a biocontrol agent against Fusarium solani, which
causes root rots with considerable losses in many important
crops, was isolated from a ginseng rhizosphere and identified
as a strain of Pseudomonas stutzeri. In several biochemical
tests with culture filtrates of P. stutzeri YPL-1 and in
mutational analyses of antifungal activities of reinforced or
defective mutants, we found that the anti-F. solani mechanism
of the bacterium may involve a lytic enzyme rather than a
toxic substance or antibiotic. P. stutzeri YPL-1 produced
extracellular chitinase and laminarinase when grown on
different polymers such as chitin, laminarin, or F. solani
mycelium. These lytic extracellular enzymes markedly inhibited
mycelial growth rather than spore germination and also caused
lysis of F. solani mycelia and germ tubes. Scanning electron
microscopy revealed degradation of the F. solani mycelium.
Abnormal hyphal swelling and retreating were caused by the
lysing agents from P. stutzeri YPL-1, and a penetration hole
was formed on the hyphae in the region of interaction with the
bacterium; the walls of this region were rapidly lysed,
causing leakage of protoplasm. Genetically bred P. stutzeri
YPL-1 was obtained by transformation of the bacterium with a
broad-host-range vector, pKT230. Also, the best conditions for
the transformation were investigated.


221                                  NAL Call. No.: 448.3 J82
Pseudomonas syringae pv. phaseolicola genomic clones harboring
heterologous DNA sequences suppress the same phaseolotoxin-
deficient mutants. Kamdar, H.V.; Rowley, K.B.; Clements, D.;
Patil, S.S.
Washington, D.C. : American Society for Microbiology; 1991
Feb. Journal of bacteriology v. 173 (3): p. 1073-1079. ill;
1991 Feb.  Includes references.

Language:  English

Descriptors: Phaseolus vulgaris; Pseudomonas syringae pv.
phaseolicola; Phaseolotoxin; Genes; Mutants; Dna; Nucleotide
sequences; Clones

Abstract:  Cosmid cloning and mutagenesis were used to
identify genes involved in the production of phaseolotoxin,
the chlorosis-inducing phytotoxin of Pseudomonas syringae pv.
phaseolicola, the causal agent of halo blight of bean
(Phaseolus vulgaris L.). Eight stable clones were isolated
from a genomic cosmid library by en masse mating to 10 ethyl
methanesulfonate (EMS)-induced Tox- mutants. In cross-matings,
each suppressed all 10 mutants as well as an additional 70
EMS-induced Tox- mutants (and one UV-induced Tox- mutant). On
the basis of restriction endonuclease analysis and
hybridization studies, the clones were grouped into three
classes. Clones in a particular class shared common fragments,
whereas clones in different classes did not. Clones from class
I (but not classes II and III) also suppressed Tns-induced Tox-
 mutants. Interposon mutagenesis and marker exchange of a
representative clone from class III into the wild-type genome
did not alter its Tox- phenotype, indicating that this clone
does not harbor structural or regulatory genes involved in
phaseolotoxin production. We suggest that the genome of P.
syringae pv. phaseolicola contains a "hot spot" in one of the
functions involved in toxin production which is affected by
EMS and UV and that heterologous clones are able to suppress
the Tox- phenotype because their inserts encode products that
are able to substitute for the product of the mutated gene.
Alternatively, the inserts may contain sequences which titrate
a repressor protein. In either case, the data suggest that
suppression of EMS-and UV-induced mutants occurs when
heterologous clones are present in multiple copies.


222                                 NAL Call. No.: 448.3 J823
Purification of the acidic pectate lyase and nucleotide
sequence of the corresponding gene (pelA) of Erwinia
chrysanthemi strain 3937. Favey, S.; Bourson, C.; Bertheau,
Y.; Kotoujansky, A.; Boccara, M. Reading : Society for General
Microbiology; 1992 Mar.
The Journal of general microbiology v. 138 (pt.3): p. 499-508;
1992 Mar. Includes references.

Language:  English

Descriptors: Erwinia chrysanthemi; Pectate lyase; Isoenzymes;
Genes; Dna; Nucleotide sequences; Amino acid sequences;
Pathogenesis-related proteins; Purification; Characterization;
Enzyme activity; Physicochemical properties

Abstract:  The pelA gene from Erwinia chrysanthemi strain
3937, which encodes the acidic pectate lyase, PLa, has been
sequenced and characterized. The structural gene consists of a
1179 bp open reading frame encoding a polypeptide of 41555 Da,
which includes an N-terminal signal peptide. The deduced amino
acid sequence shows a protein very similar to some PLs already
sequenced. Cloning of the pelA gene behind the lacZ promoter
of the vector pTZ19R allowed overexpression of PLa into a
derivative of strain 3937 deleted of the other pel genes. The
mature protein was obtained in milligram amounts from the
supernatant of this strain and at homogeneous purity after two
purification steps. Its biochemical properties were similar to
those of other PLs. Polyclonal antibodies raised against the
purified PLa cross-reacted with the basic pectate lyase PLd,
but not with PLe. The role of PLa in pathogenicity is
discussed.


223                                 NAL Call. No.: QL391.N4R4
Quantitative ELISA for the detection of potato cyst nematodes
in soil samples. Schots, A.; Gommers, F.J.; Egberts, E.
Montrouge : Gauthier-Villars; 1992.
Fundamental and applied nematology v. 15 (1): p. 55-61; 1992. 
Includes references.

Language:  English

Descriptors: Solanum tuberosum; Globodera rostochiensis;
Globodera pallida; Detection; Soil; Samples; Elisa; Monoclonal
antibodies


224                                  NAL Call. No.: SB599.P45
Rapid induction of systemic resistance in cucumber by
Pseudomonas syringae pv. syringae.
Smith, J.A.; Hammerschmidt, R.; Fulbright, D.W.
London : Academic Press; 1991 Mar.
Physiological and molecular plant pathology v. 38 (3): p.
223-235; 1991 Mar. Includes references.

Language:  English

Descriptors: Cucumis sativus; Pseudomonas syringae pv.
syringae; Disease resistance; Induced resistance; Enzyme
activity; Peroxidase; Hypersensitivity; Mutants; Plasmids;
Vectors; Genetic transformation; Genetic regulation;
Pseudomonas syringae pv. lachrymans; Colletotrichum orbiculare

Abstract:  Inoculation of the first leaf of cucumber with
Pseudomonas syringae pv. syringae (wheat isolate) elicited a
rapid hypersensitive response and also induced systemic
resistance to Colletotrichum lagenarium. Systemic increases in
peroxidase activity and resistance were observed within 1 day
of inoculation with P. syringae pv. syringae. The induction of
systemic resistance and peroxidase activity by P. syringae pv.
syringae was at least 4 days faster than that observed for the
cucumber pathogen Pseudomonas syringae pv. lachrymans.
Detaching the leaf inoculated with P. syringae pv. syringae at
intervals after inoculation demonstrated that the signal(s)
involved in systemic induced resistance and increases in
peroxidase was generated within 6 h after the inducing
inoculation and before the development of visible necrosis.
Tn5 mutants of P. syringae pv. syringae, selected for their
inability to induce the hypersensitive response and systemic
peroxidase activity in cucumber, had also lost their ability
to elicit systemic disease resistance in cucumber and cause
disease on wheat. A genomic clone was isolated from a library
of P. syringae pv. syringae which restored the ability of both
mutants to induce the hypersensitive response, systemic
disease resistance and peroxidase activity. The rapidity and
level of resistance induced by P. syringae pv. syringae
suggest that this organism may be useful in future studies on
the nature of systemic signaling and the regulation of induced
resistance in cucurbits.


225                            NAL Call. No.: TP248.65.F66F66
Raw materials: introducting pest resistance in plants to
create "green" raw materials.
Stiekema, W.J.
New York, N.Y. : Marcel Dekker, Inc.; 1991.
Food biotechnology v. 5 (3): p. 229-237; 1991.  Includes
references.

Language:  English

Descriptors: Crop production; Biotechnology; Genetic
engineering; Pest resistance


226                                  NAL Call. No.: 442.8 Z34
Recombination at the Rp1 locus of maize.
Hulbert, S.H.; Bennetzen, J.L.
Berlin, W. Ger. : Springer International; 1991 May.
M G G : Molecular and general genetics v. 226 (3): p. 377-382;
1991 May. Includes references.

Language:  English

Descriptors: Zea mays; Puccinia sorghi; Loci; Recombination;
Genetic resistance; Rust diseases; Genetic markers;
Restriction fragment length polymorphism; Alleles;
Duplication; Crossing over; Segregation; Molecular mapping;
Gene mapping

Abstract:  The Rp1 locus of maize determines resistance to
races of the maize rust fungus (Puccinia sorghi). Restriction
fragment length polymorphism markers that closely flank Rp1
were mapped and used to study the genetic fine structure and
role of recombination in the instability of this locus.
Susceptible progeny, lacking the resistance of either parent,
were obtained from test cross progeny of several Rp1
heterozygotes. These susceptible progeny usually had non-
parental genotypes at flanking marker loci, thereby verifying
their recombinational origin. Seven of eight Rp1 alleles (or
genes) studied were clustered within about 0.2 map units of
each other. Rp1(G), however, mapped from 1-3 map units distal
to other Rp1 alleles. Rp5 also mapped distally to most Rp1
alleles. Other aspects of recombination at Rp1 suggested that
some alleles carry duplicated sequences, that mispairing can
occur, and that unequal crossing-over may be a common
phenomenon in this region; susceptible progeny from an Rp1(A)
homozygote had recombinant flanking marker genotypes, and
susceptible progeny from an Rp1(D)/Rp1(F) heterozygote showed
both possible nonparental flanking marker genotypes.


227                                  NAL Call. No.: QH301.N32
Regeneration and transformation experiments in apple.
Welander, M.; Maheswaran, G.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 237-246.
ill; 1991.  In the series analytic: Woody plant biotechnology
/ edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Includes references.

Language:  English

Descriptors: Malus pumila; Cultivars; Genetic transformation;
Agrobacterium tumefaciens


228                                 NAL Call. No.: QH442.A1G4
Regulation and secretion of an extracellular esterase from
Streptomyces scabies.
Schottel, J.L.; Hale, V.; Babcock, M.J.
Amsterdam : Elsevier Science Publishers; 1992.
Gene v. 115 (1/2): p. 27-31; 1992.  Paper presented at the
"Eighth International Symposium on Biology of Actinomycetes,"
August 11-16, 1991, Madison, Wisconsin.  Includes references.

Language:  English

Descriptors: Streptomyces scabies; Streptomyces; Structural
genes; Esterases; Genetic transformation; Gene transfer; Gene
expression; Transcription; Secretion; Zinc; Genetic
regulation; Binding site; Dna binding proteins; Enzyme
activity; Nucleotide sequences; Amino acid sequences

Abstract:  Production of a heat-stable, extracellular esterase
by Streptomyces scabies is regulated by zinc ions. The
esterase-encoding gene (est) from S. scabies was cloned and
expressed in Streptomyces lividans. In S. lividans, expression
of the est gene is also regulated by Zn2+, and the esterase is
efficiently secreted in this organism. The sequence of the est
gene suggests that a 39-amino acid signal peptide is removed
during secretion of this protein. Deletion analysis has
indicated that the hydrophobic domain of the signal peptide is
required for secretion. Gel retardation assays and DNaseI
footprinting using an S-30 protein extract from S. scabies
have previously identified a specific 23-bp protein-binding
site upstream from the est coding sequence. Deletion of this
protein-binding sequence significantly decreased expression of
the est gene.


229                                  NAL Call. No.: SB599.P45
Relationships between electrolyte leakage from Pyrus communis
and virulence of Erwinia amylovora.
Brisset, M.N.; Paulin, J.P.
London : Academic Press; 1991 Jun.
Physiological and molecular plant pathology v. 38 (6): p.
443-453; 1991 Jun. Includes references.

Language:  English

Descriptors: Pyrus communis; Infections; Erwinia amylovora;
Host parasite relationships; Cell membranes; Leakage;
Electrolytes; Ions; Strain differences; Virulence; Mutants;
Strains; Transgenics; Erwinia herbicola; Pseudomonas syringae
pv. phaseolicola; Pseudomonas syringae pv. tabaci

Abstract:  One of the first events associated with the
interaction between a necrogenic bacterial pathogen and cells
of plant tissues is the leakage of electrolytes and nutrients
through the plant cell membranes. A technique, used previously
to measure electrolyte leakage from bean leaves infiltrated
with Pseudomonas syringae pv. syringae, was adapted and used
to study the pattern and extent of leakage from pear tissues
treated with wild-type strains and transposon mutants of
Erwinia amylovora of different levels of virulence. Results
showed that electrolyte leakage from pear treated with E.
amylovora can be easily and reliably assessed. Furthermore,
there is a correlation (with extracellular polysaccharide
producing strains) between the level of virulence of the
strains and the amount of leaked electrolytes.


230                                   NAL Call. No.: QH540.S8
Release of genetically-engineered microorganisms in the
environment: risk of horizontal genetic-transfer.
Hoekstra, W.P.M.
New York, N.Y. : Elsevier Science Publishing Company Inc;
1991. Studies in environmental science (42): p. 351-357; 1991. 
In the series analytic: Environmental biotechnology / edited
by A. Blazej and V. Privarova. Proceedings of the
International Symposium on Biotechnology, June 27-29, 1990,
Bratislava, Czechoslovakia.  Includes references.

Language:  English

Descriptors: Microorganisms; Microbial pesticides; Pseudomonas
syringae; Genetic engineering; Introduced species;
Environmental impact; Ice nucleation; Gene transfer; Genetic
transformation


231                                  NAL Call. No.: 442.8 Z34
Repeats and subrepeats in the intergenic spacer of rDNA from
the nematode Meloidogyne arenaria.
Vahidi, H.; Honda, B.M.
Berlin, W. Ger. : Springer International; 1991 Jun.
M G G : Molecular and general genetics v. 227 (2): p. 334-336;
1991 Jun. Includes references.

Language:  English

Descriptors: Meloidogyne arenaria; Ribosomal  RNA; Genes;
Ribosomal  DNA; Repetitive  DNA; Nucleotide sequences;
Deletions; Recombination

Abstract:  Ribosomal DNA (rDNA) repeats of the plant-parasitic
nematode Meloidogyne arenaria are heterogeneous in size and
appear to contain 5S rRNA gene sequences. Moreover, in a recA+
bacterial host, plasmid clones of a 9 kb rDNA repeat show
deletion events within a 2 kb intergenic spacer (IGS), between
28S and 5S DNA sequences. These deletions appear to result
from a reduction in the number of tandem 129 bp repeats in the
IGS. The loss of such repeats might explain how rDNA length
heterogeneity, observed in the Meloidogyne genome, could have
arisen. Each 129 bp repeat also contains three copies of an 8
bp subrepeat, which has sequence similarity to an element
found in the IGS repeats of some plant rDNAs.


232                                 NAL Call. No.: 440.9 R81J
A review of methods for the production and use of monoclonal
antibodies to study zoosporic plant pathogens.
Hardham, A.R.; Gubler, F.; Duniec, J.; Elliott, J.
Oxford : Blackwell Scientific Publications; 1991 Jun.
Journal of microscopy v. 162 (3): p. 305-318; 1991 Jun. 
Includes references.

Language:  English

Descriptors: Phytophthora cinnamomi; Pythium aphanidermatum;
Zoospores; Infection; Monoclonal antibodies; Surface antigens;
Immunofluorescence; Immunocytochemistry


233                                NAL Call. No.: S592.7.A1S6
Rhizosphere growth of Pseudomonas solanacearum genetically
altered in extracellular enzyme production.
Williamson, J.W.; Hartel, P.G.
Exeter : Pergamon Press; 1991.
Soil biology and biochemistry v. 23 (5): p. 453-458; 1991. 
Includes references.

Language:  English

Descriptors: Lycopersicon esculentum; Portulaca oleracea;
Pennisetum Americanum; Polygalacturonase; Enzymes; Genes;
Plasmids; Mutagenesis; Enzyme activity; Virulence; Growth;
Population density; Rhizosphere

Abstract:  The alteration of specific genes in a bacterium may
help in understanding the ecological significance of the
genes. In this study we determined the effects of alterations
of a single gene (encoding endopolygalacturonase A) and two
genes combined (encoding endopolygalacturonase A and
endoglucanase) on growth of Pseudomonas solanacearum (the
causal agent of bacterial wilt) in soil and in the
rhizospheres of host and nonhost plants. The levels of
endopolygalacturonase A, or endopolygalacturonase A and
endoglucanase production by P. solanacearum were either
reduced by insertion mutagenesis or enhanced by increasing the
gene copy number with a recombinant plasmid. In addition,
changes in virulence of the genetically altered strains were
determined by soil inoculation. Under nonsterile conditions,
population densities of all strains failed to increase in
rhizosphere and nonrhizosphere soils of tomato (Lycopersicon
esculentum Mill. cv. Marion), common purslane (Portulaca
oleracea L.), and pearl millet [Pennisetum glaucum (L.)
R.Br.]. Under gnotobiotic conditions, all strains grew in the
rhizosphere of tomato, but the genetically altered strains had
< 1-81% lower maximal cell densities, and 9-108% longer
generation times. Strains with enhanced enzyme activity were
avirulent, possibly because of an impaired ability to grow.
Strains with reduced enzyme activity showed little difference
in virulence compared to the wild type strain. Our data
suggest that a reduction of endopolygalacturonase A, or a
reduction of endopolygalacturonase A coupled with an
inactivation of endoglucanase production, is of minor
importance to the rhizosphere growth of P. solanacearum.


234                                    NAL Call. No.: 475 EX7
Role of toxins in evolution and ecology of plant pathogenic
fungi. Scheffer, R.P.
Basel : Birkhauser; 1991 Aug.
Experientia v. 47 (8): p. 804-811; 1991 Aug.  Literature
review.  Includes references.

Language:  English

Descriptors: Plant pathogenic fungi; Cochliobolus; Alternaria;
Phytotoxins; Evolution; Ecology; Genetics; Literature reviews


235                                NAL Call. No.: SB732.6.M65
Role of T-region borders in Agrobacterium host range.
Paulus, F.; Huss, B.; Tinland, B.; Herrmann, A.; Canaday, J.;
Otten, L. St. Paul, Minn. : APS Press; 1991 Mar.
Molecular plant-microbe interactions : MPMI v. 4 (2): p.
163-172; 1991 Mar. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Nicotiana rustica; Vitis
vinifera; Agrobacterium tumefaciens; Host range; Host parasite
relationships; Oncogenes; Auxins; Biosynthesis; Genetic
regulation; Strains; Strain differences; Tumors; Plasmids;
Pathogenicity; Evolution; Gene expression; Nucleotide
sequences; Genetic analysis; Molecular genetics


236                                  NAL Call. No.: 1.98 AG84
Rust-no-more beans: new varieties fend off all 55 known rust-
causing fungi. De Quattro, J.
Washington, D.C. : The Service; 1992 Feb.
Agricultural research - U.S. Department of Agriculture,
Agricultural Research Service v. 40 (2): p. 12-14; 1992 Feb.

Language:  English

Descriptors: Phaseolus vulgaris; Rust diseases; Disease
resistance; Genetic engineering


237                                 NAL Call. No.: QH442.A1G4
Sequence analysis of an insertion element, IS1131, isolated
from the nopaline-type Ti plasmid of Agrobacterium
tumefaciens.
Wabiko, H.
Amsterdam : Elsevier Science Publishers; 1992.
Gene v. 114 (2): p. 229-233; 1992.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Genes;
Nucleotide sequences; Transposable elements; Nopaline;
Repetitive  DNA; Strain differences; Pathogenicity;
Restriction mapping; Crown gall

Abstract:  Transferred DNA (T-DNA) from several nopaline-type
Ti plasmids of Agrobacterium tumefaciens was previously shown
to be variable in size due to the insertion of extra DNA
segments. We found an insertion sequence (named IS1131) in the
T-DNA of the strain PO22 and determined the nucleotide (nt)
sequence. IS1131 is 2773 bp long, contains four open reading
frames, and is flanked by 12-bp perfect inverted repeats (IR).
An 8-bp direct repeat was found immediately outside the IR,
and represents a target site of integration. Although the
IS1131 nt sequence showed a limited degree of similarity to
those of the previously reported IS elements of A. tumefaciens
and to the central region of T-DNA, the terminal IR of IS1131
were highly homologous (up to 83%) to those of IS66 and IS866,
suggesting that these three IS elements are related to each
other. A number of IS1131-related copies were found in several
pathogenic, as well as nonpathogenic, nopaline-type strains
from different plant sources, and were distributed on both
chromosomes and plasmids.


238                                 NAL Call. No.: QH442.A1G4
Sequence analysis of the cellulase-encoding celY gene of
Erwinia chrysanthemi: a possible case of interspecies gene
transfer.
Guiseppi, A.; Aymeric, J.L.; Cami, B.; Barras, F.; Creuzet, N.
Amsterdam : Elsevier Science Publishers; 1991.
Gene v. 106 (1): p. 109-114; 1991.  Includes references.

Language:  English

Descriptors: Erwinia chrysanthemi; Genes; Cellulase; Cloning;
Nucleotide sequences; Promoters; Amino acid sequences;
Evolution; Gene transfer; Cellulomonas

Abstract:  The Erwinia chrysanthemi (strain 3937) celY gene
encoding the minor endoglucanase (EGY) was sequenced. The
analysis of the upstream region allowed us to identify an in
vivo active promoter recognized by the NtrA (sigma 54)
holoenzyme. No similarity was found between the predicted
amino acid (aa) sequences of EGY and either the Er.
chrysanthemi major endoglucanase, EGZ, or the Er. carotovora
CelS endoglucanase. In contrast, a very high level of
identity, both at the nucleotide and the predicted aa levels,
was found between celY and an EG-encoding gene from
Cellulomonas uda, a Gram+ bacterium taxonomically distant from
Er. chrysanthemi. By comparing the molar G + C% of the
cellulase-encoding genes and that of Er. chrysanthemi and C.
uda chromosomal DNAs, we speculate that celY was transferred
from Er. chrysanthemi to C. uda.


239                                  NAL Call. No.: 448.3 J82
Sequence domains required for the activity of avirulence genes
avrB and avrC from Pseudomonas syringae pv. glycinea.
Tamaki, S.J.; Kobayashi, D.Y.; Keen, N.T.
Washington, D.C. : American Society for Microbiology; 1991
Jan. Journal of bacteriology v. 173 (1): p. 301-307; 1991 Jan. 
Includes references.

Language:  English

Descriptors: Glycine max; Pseudomonas syringae pv. glycinea;
Genes; Disease resistance; Nucleotide sequences; Phenotypes

Abstract:  avrB and avrC from Pseudomonas syringae pv.
glycinea share significant amino acid homology but interact
with different soybean resistance genes to elicit the
hypersensitive defense reaction. Recombinant genes constructed
between avrB and avrC revealed that the central regions were
required for avirulence gene activity but the 5' and 3'
termini were interchangeable. Recombinants involving the
central regions did not yield any detectable avirulence gene
activity, and no new avirulence phenotypes were observed from
any of the chimeric genes. These results suggest that the
protein products of avrB and avrC possess catalytic properties
that are required for the avirulence phenotypes.


240                                   NAL Call. No.: 500 N21P
Sequence identity in the nick regions of IncP plasmid transfer
origins and T-DNA borders of Agrobacterium Ti plasmids.
Waters, V.L.; Hirata, K.H.; Pansegrau, W.; Lanka, E.; Guiney,
D.G. Washington, D.C. : The Academy; 1991 Feb15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (4): p. 1456-1460; 1991 Feb15. 
Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Dna sequencing;
Molecular genetics; Mutagenesis; Nucleotide sequences;
Plasmids


241                                  NAL Call. No.: QK710.P62
Sequence of Agrobacterium tumefaciens biotype III auxin genes.
Bonnard, G.; Vincent, F.; Otten, L.
Dordrecht : Kluwer Academic Publishers; 1991 Apr.
Plant molecular biology : an international journal on
fundamental research and genetic engineering v. 16 (4): p.
733-738; 1991 Apr.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Genes;
Nucleotide sequences; Amino acid sequences; Biotypes;
Octopine; Amino acid derivatives; Evolution


242                                  NAL Call. No.: QK710.P62
Sequence of the iaa and ipt region of different Agrobacterium
tumefaciens biotype III octopine strains: reconstruction of
octopine Ti plasmid evolution. Paulus, F.; Canaday, J.;
Vincent, F.; Bonnard, G.; Kares, C.; Otten, L. Dordrecht :
Kluwer Academic Publishers; 1991 Apr.
Plant molecular biology : an international journal on
fundamental research and genetic engineering v. 16 (4): p.
601-614; 1991 Apr.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Genes;
Nucleotide sequences; Amino acid sequences; Evolution; Strain
differences; Cloning; Gene transfer; Octopine; Amino acid
derivatives; Iaa; Biosynthesis; Restriction mapping;
Transcription; Genetic transformation; Kalanchoe
daigremontiana; Rooting

Abstract:  The TA regions of biotype Ill octopine/cucumopine
(OC) Ti plasmids are closely related to theTL region of the
biotype I octopine Ti plasmids pTiAch5 andpTi15955. Sequence
analysis shows that the limited and wide host range biotype
III OC TA regions are derived from acommon ancestor structure
which lacked the 6a gene found in the biotype I octopine TL
region. TheTA region of the wide host range OC Ti plasmids has
conserved most of the original TL-like structure.In most wide
host range OC isolates the TA-iaaH gene is inactivated by the
insertion of an IS866element. However, the TA region of the
wide host range isolate Hm1 carries an intact TA-iaaH gene.
Thisgene encodes a biologically active product, as shown by
root induction tests and indole-3-aceticacid measurements. The
limited host range OC Ti plasmids pTiAB3 and pTiAg57
haveshorter TA regions which are derived from a wide host
range TA region. The AB3 type arose byan IS868-mediated,
internal TA region deletion which removed the iaa genes and
part of the ipt gene andleft a copy of IS868 at the position
of the deleted fragment. The pTiAB3 iaa/ipt deletion was
followedby insertion of a second IS element, IS869,
immediately 3' of the ipt gene. pTiAg57 underwent the sameiaa-
ipt deletion as pTiAB3, but lacks the IS868 and IS869
elements. Analysis of the various TA region structures
provides a detailedinsight into the evolution of the biotype
Ill OC strains.


243                                   NAL Call. No.: QK600.E9
Sexual crosses of the homothallic fungus Gaeumannomyces
graminis var. tritici based on use of an auxotroph obtained by
transformation.
Pilgeram, A.L.; Henson, J.M.
Orlando, Fla. : Academic Press; 1992 Mar.
Experimental mycology v. 16 (1): p. 35-43; 1992 Mar.  Includes
references.

Language:  English

Descriptors: Gaeumannomyces graminis; Genetic transformation;
Genes; Oxidoreductases; Linkage; Segregation; Crosses; Genetic
markers; Ascospores; Benomyl; Fungicide tolerance; Drug
resistance; Antineoplastic agents; Nutrient requirements;
Nicotinic acid; Pathogenicity; Fungal diseases; Triticum
aestivum


244                                   NAL Call. No.: 500 N21P
A short C-terminal sequence is necessary and sufficient for
the targeting of chitinases to the plant vacuole.
Neuhaus, J.M.; Sticher, L.; Meins, F. Jr; Boller, T.
Washington, D.C. : The Academy; 1991 Nov15.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (22): p. 10362-10366; 1991 Nov15. 
Includes references.

Language:  English

Descriptors: Cucumis sativus; Nicotiana sylvestris; Nicotiana
tabacum; Plant secretions; Vacuoles; Amino acid sequences;
Chitinase; Defense mechanisms; Disease resistance; Enzyme
activity; Fungal diseases; Gene expression; Polypeptides

Abstract:  Tobacco contains different isoforms of chitinase
(EC 3.2.1.14), a hydrolase thought to be involved in the
defense against pathogens. Deduced amino acid sequences for
putatively vacuolar, basic chitinases differ from the
homologous extracellular, acidic isoforms by the presence of a
C-terminal extension. To examine the role of this C-terminal
extension in protein sorting, Nicotiana silvestris plants were
stably transformed with chimeric genes coding for tobacco
basic chitinase A with and without the seven C-terminal amino
acids. In plants expressing unmodified chitinase A, the enzyme
activity was low in the intercellular wash fluid but high in
protoplasts and isolated vacuoles. In contrast, in plants
expressing mutant chitinase lacking the C terminus, the
activity was high in the intercellular wash fluid but low in
protoplasts. N. silvestris plants were also transformed with
similar constructions coding for a structurally unrelated,
extracellular cucumber chitinase. In plants expressing
unmodified cucumber chitinase, its activity was present in the
intercellular wash fluid and absent from protoplasts. In
plants expressing cucumber chitinase with the C-terminal
extension from tobacco chitinase A, activity was low in
intercellular wash fluids but high in protoplasts and
vacuoles. These results demonstrate that the C-terminal
extension of tobacco chitinase A is necessary and sufficient
for the vacuolar localization of chitinases and, therefore,
that it comprises a targeting signal for plant vacuoles.


245                                   NAL Call. No.: QH426.C8
A single amino-acid substitution in the beta-tubulin gene of
Neurospora confers both carbendazim resistance and
diethofencarb sensitivity. Fujimura, M.; Oeda, K.; Inoue, H.;
Kato, T.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (4/5): p. 399-404; 1992.  Includes
references.

Language:  English

Descriptors: Neurospora crassa; Loci; Tubulin; Genes; Induced
mutations; Mutants; Carbendazim; Carbamate pesticides;
Fungicides; Fungicide tolerance; Fungicidal properties;
Nucleotide sequences; Segregation; Amino acid sequences

Abstract:  Two MBC-resistant mutants of Neurospora crassa,
F914 and F939, were sensitive to diethofencarb at a
concentration of 0.1 microgram/ml, while the wild-type strain
and other MBC-resistant mutants showed resistance to
diethofencarb at a concentration of 100 microgram/ml. Genetic
analysis suggested that the mutations in these two strains
were closely linked to the Bml locus which codes for beta-
tubulin. When the wild-type strain was transformed by the
cloned beta-tubulin gene of the F914 strain, the transformants
showed both MBC resistance and diethofencarb sensitivity. On
the other hand, the diethofencarb sensitivity of the F914
strain was cancelled by transformation with the wild-type
beta-tubulin gene. DNA sequencing of F914 beta-tubulin
revealed that glycine was substituted for glutamic acid at
position 198 in the F914 strain. Therefore, a single base
change in the beta-tubulin gene was proved to confer both MBC
resistance and diethofencarb sensitivity.


246                                  NAL Call. No.: 448.3 AP5
The solubility of inclusion proteins from Bacillus
thuringiensis is dependent upon protoxin composition and is a
factor in toxicity to insects. Aronson, A.I.; Han, E.S;
McGaughey, W.; Johnson, D.
Washington, D.C. : American Society for Microbiology; 1991
Apr. Applied and environmental microbiology v. 57 (4): p.
981-986; 1991 Apr. Includes references.

Language:  English

Descriptors: Bacillus thuringiensis subsp. aizawai; Bacillus
thuringiensis subsp. kurstaki; Bacterial insecticides; Nuclear
inclusions; Bacterial toxins; Thuringiensin; Precursors;
Solubility; Ph; Dna probes; Genes; Dna hybridization;
Bioassays; Toxicity; Manduca sexta; Trichoplusia ni;
Spodoptera frugiperda; Heliothis virescens; Plodia
interpunctella

Abstract:  Bacillus thuringiensis subsp. aizawai HD133 is one
of several strains particularly effective against Plodia
interpunctella selected for resistance to B. thuringiensis
subsp. kurstaki HD1 (Dipel). B. thuringiensis subsp. aizawai
HD133 produces inclusions containing three protoxins,
CryIA(b), CryIC, and CryID, and the CryIC protoxin has been
shown to be active on resistant P. interpunctella as well as
on Spodoptera larvae. The CryIA(b) protoxin is very similar to
the major one in B. thuringiensis subsp. kurstaki HD1, and as
expected, this protoxin was inactive on resistant P.
interpunctella. A derivative of B. thuringiensis subsp.
aizawai HD133 which had been cured of a 68-kb plasmid
containing the cryIA(b) gene produced inclusions comprising
only the CryIC and CryID protoxins. Surprisingly, these
inclusions were much less toxic for resistant P.
interpunctella and two other Lepidoptera than those produced
by the parental strain, whereas the soluble protoxins from
these strains were equally effective. In contrast, inclusions
from the two strains were about as active as soluble protoxins
for Spodoptera frugiperda larvae, so toxicity differences
between inclusions may be due to the solubilizing conditions
within particular larval guts. Consistent with this
hypothesis, it was found that a higher pH was required to
solubilize protoxins from inclusions from the plasmid-cured
strain than from B. thuringiensis subsp. aizawai HD133, a
difference which is probably, attributable to the absence of
the CryIA(b) protoxin in the former. The interactions of
structurally related protoxins within an inclusion are
probably important for solubility and are thus another factor
in the effectiveness of B. thuringiensis isolates for
particular insect larvae.


247                                  NAL Call. No.: 448.3 J82
Spontaneous mutation conferring the ability to catabolize
mannopine in Agrobacterium tumefaciens.
LaPointe, G.; Nautiyal, C.S.; Chilton, W.S.; Farrand, S.K.;
Dion, P. Washington, D.C. : American Society for Microbiology;
1992 Apr. Journal of bacteriology v. 174 (8): p. 2631-2639;
1992 Apr.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Mutations; Catabolism;
Amino acid derivatives; Plasmids

Abstract:  Two nopaline-type strains of Agrobacterium
tumefaciens, C58 and T37, as well as strain A136, which is a
Ti plasmid-cured derivative of strain C58, gave rise to
spontaneous mutants that were able to grow on mannopine. The
observation of mutagenesis with strain A136 demonstrated that
the ability to acquire this new catabolic potential was
independent of the presence of a Ti plasmid. The mutants were
isolated after 4 weeks of incubation on minimal medium
containing mannopine as the sole carbon source. They also
utilized mannopinic acid, but not agropine or agropinic acid.
In addition, the spontaneous mutant LM136, but not its parent
strain A136, degraded many mannityl opine analogs.
[(14)C]mannopine disappeared in the presence of LM136 cells
which had been pregrown on opine or nonopine substrates. These
results suggested that the catabolic system of this mutant was
not subject to a stringent regulation. A clone conferring the
ability to utilize mannopine on a recipient pseudomonad was
selected from a genomic library from both the mutant LM136 and
its parent strain. Only the LM136 clone was expressed in the
parent Agrobacterium strain A136. Southern analysis showed
that the genes for mannopine catabolism in the spontaneous
mutants differed from the corresponding Ti plasmid-encoded
genes of octopine-type or agropine-type Agrobacterium strains.
Cells of LM136 utilized [(14)C]mannopine without generating
detectable amounts of intracellular agropine. In contrast, a
major fraction of the radioactivity recovered from cells of
the octopine-type strain Ach5, after incubation on
[14C]mannopine, was in the form of agropine.


248                                  NAL Call. No.: 448.3 J82
Stimulation of Agrobacterium tumefaciens T-DNA transfer by
overdrive depends on a flanking sequence but not on helical
position with respect to the border repeat.
Shurvinton, C.E.; Ream, W.
Washington, D.C. : American Society for Microbiology; 1991
Sep. Journal of bacteriology v. 173 (17): p. 5558-5563; 1991
Sep.  Includes references.

Language:  English

Descriptors: Solanum tuberosum; Agrobacterium tumefaciens;
Plasmids; Dna; Controlling elements; Nucleotide sequences;
Genetic transformation; Virulence; Crown gall; Tumors;
Synthetic genes

Abstract:  T-DNA transfer by Agrobacterium tumefaciens depends
on the right border repeat of the T-DNA and is greatly
stimulated by overdrive, an adjacent sequence. We report that
the function of overdrive does not depend on helical position
with respect to the border repeat. A synthetic 24-bp overdrive
and a 12-bp region containing a fully conserved 8-bp core
overdrive sequence stimulated virulence equally, but full
function required additional bases to the left of the 24-bp
sequence.


249                                  NAL Call. No.: QK710.P62
Stress responses in alfalfa (Medicago sativa L.) 12. Sequence
analysis of phenylalanine ammonia-lyase (PAL) cDNA clones and
appearance of PAL transcripts in elicitor-treated cell
cultures and developing plants. Gowri, G.; Paiva, N.L.; Dixon,
R.A.
Dordrecht : Kluwer Academic Publishers; 1991 Sep.
Plant molecular biology : an international journal on
molecular biology, biochemistry and genetic engineering v. 17
(3): p. 415-429; 1991 Sep. Includes references.

Language:  English

Descriptors: Medicago sativa; Colletotrichum lindemuthianum;
Multigene families; Phenylalanine ammonia-lyase; Messenger 
RNA; Cloning; Nucleotide sequences; Amino acid sequences; Gene
expression; Cell suspensions; Roots; Stems; Leaves; Flowers;
Cell wall components; Disease resistance; Enzyme activity

Abstract:  An expression library containing cDNAs derived from
transcripts from fungal elicitor-treated alfalfa cell
suspension cultures was screened with an antiserum raised
against phenylalanine ammonia-lyase (PAL) from alfalfa. A
single immunoreactive clone was isolated which encoded a full-
length PAL cDNA (APAL1) consisting of a 2175 bp open reading
frame, 96 bp 5'-untranslated leader and 128 bp 3'-non-coding
region. The deduced amino acid sequence was 86.5% similar to
that of the PAL2 gene of bean, and encoded a polypeptide of Mr
78865. A second PAL cDNA species was isolated, whose 3'-
untranslated region was 86% identical to that of APAL1.
Southern blot analysis indicated that PAL is encoded by a
small multigene family in alfalfa. PAL transcript levels were
rapidly and massively induced, and preceded increased PAL
extractable activity, on exposure of alfalfa suspension cells
to elicitor from baker's yeast. PAL transcripts were most
abundant in roots, stems and petioles during growth and
development of alfalfa seedlings. These studies provide the
basis for an examination of the developmental and
environmental control of a key enzyme of phenylpropanoid
synthesis in a plant species which is readily amenable to
stable genetic transformation.


250                                  NAL Call. No.: QK710.P62
Stress responses in alfalfa (Medicago sativa L.). 8. Cis-
elements and trans-acting factors for the quantitative
expression of a bean chalcone synthase gene promoter in
electroporated alfalfa protoplasts. Harrison, M.J.; Choudhary,
A.D.; Dubery, I.; Lamb, C.J.; Dixon, R.A. Dordrecht : Kluwer
Academic Publishers; 1991 May.
Plant molecular biology : an international journal on
fundamental research and genetic engineering v. 16 (5): p.
877-890; 1991 May.  Includes references.

Language:  English

Descriptors: Medicago sativa; Phaseolus vulgaris; Genetic
transformation; Electroporation; Protoplasts; Direct 
DNAuptake; Gene expression; Naringenin-chalcone synthase;
Promoters; Chimeras; Chloramphenicol acetyltransferase;
Reporter genes; Position effect; Dna binding proteins;
Nucleotide sequences; Binding site; Defense mechanisms; Cell
wall components; Colletotrichum lindemuthianum

Abstract:  A chimeric gene consisting of a bean (Phaseolus
vulgaris L.) chalcone synthase (CHS) promoter fused to a
bacterial chloramphenicol acetyltransferase (CAT) reporter
gene was strongly expressed, and further induced by fungal
elicitor, when electroporated into alfalfa (Medicago sativa
L.) suspension cell protoplasts. Functional analysis of 5'
deletions of the CHS promoter-CAT construct in these
protoplasts indicated that the region between -326 and -130
contained both activator and silencer elements. Co-
electroporation experiments confirmed that these cis-acting
elements were binding sites for functionally active trans
factors. In vitro DNase I footprinting revealed four potential
binding sites for alfalfa suspension cell nuclear proteins
between positions -326 and -130 of the CHS promoter. These
sites mapped to regions shown to contain functional cis-acting
elements on the basis of the deletion analysis. Three of these
sites mapped to previously identified binding sites for bean
nuclear proteins. Competition gel retardation analysis using
oligonucleotide probes containing binding site sequences
revealed sequence-specific binding of alfalfa nuclear proteins
to an AT-rich element and a putative GT-1 factor consensus
binding sequence. Our results define cis elements and their
cognate trans factors functionally active in determining the
quantitative expression of a defense response gene in a
heterologous transient expression system.


251                                  NAL Call. No.: QK725.P54
Suppression of the powdery mildew pathogen by chitinase
microinjected into barley colecptile epidermal cells.
Toyoda, H.; Matsuda, Y.; Yamaga, T.; Ikeda, S.; Morita, M.;
Tamai, T.; Ouchi, S.
Berlin, W. Ger. : Springer International; 1991.
Plant cell reports v. 10 (5): p. 217-220; 1991.  Includes
references.

Language:  English

Descriptors: Hordeum vulgare; Coleoptiles; Epidermis; Genetic
transformation; Streptomyces griseus; Plant pathogenic fungi;
Erysiphe graminis; Genetic resistance; Chitinase; Enzyme
inhibitors; Pathogenicity

Abstract:  An exogenous chitinase from Streptomyces griseus
was introduced into coleoptile epidermal cells of barley
(Hordeum vulgare) by microinjection, and the effect of
injected chitinase on the growth or development of the powdery
mildew pathogen (Erysiphe graminis f. sp. hordei) was
examined. Prior to microinjection, an enzymatic degradation of
fungal haustorium, the organ taking nutrients from host plant
cells, was examined by treating fixed coleoptile epidermis
harboring haustoria with this enzyme. The result showed that
haustoria were effectively digested by chitinase, suggesting
the effectiveness of chitinase treatment for suppressing the
fungal development. Microinjection of chitinase was conducted
using living coleoptile tissues inoculated with the pathogen.
Epidermal cells in which the haustorial primordia had been
formed, or in which the haustoria had matured, were selected
as targets for injection. The result clearly indicated that
injection at the stage of primordium formation was effective
in completely digesting haustoria and suppressing the
subsequent formation of secondary hyphae of the pathogen. In
microinjection after haustorial maturation, hyphal elongation
was considerably suppressed though there was no detectable
morphological change in the haustoria. Thus, the present study
provides the experimental basis for genetically manipulating
barley to produce transgenic plants resistant to the powdery
mildew disease.


252                                    NAL Call. No.: QR1.F44
Survival of genetically engineered Pseudomonas fluorescens in
soil in competition with the parent strain.
Elsas, J.D. van; Overbeek, L.S. van; Feldmann, A.M.;
Dullemans, A.M.; Leeuw, O. de
Amsterdam : Elsevier Science Publishers; 1991 Feb.
FEMS microbiology letters - Federation of European
Microbiological Societies v. 85 (1): p. 53-64. ill; 1991 Feb. 
Includes references.

Language:  English

Descriptors: Netherlands; Pseudomonas fluorescens; Soil
bacteria; Strains; Genetic engineering; Transposable elements;
Genetic markers; Growth; Survival; Competitive ability;
Population dynamics; Soil sterilization; Soil types (textural)

Abstract:  The population dynamics of two genetically
engineered Pseudomonas fluorescens strains, D5 and C5t,
introduced into a loamy sand soil, in competition with a
spontaneous antibiotic-resistant mutant of the corresponding
wildtype strain was studied. Strain D5 contained an insertion
of transposon Tn5 in its genome, whereas strain C5t was
obtained by insertion of Tn5::tox, a Tn5-derivative containing
a Bacillus thuringiensis var. morrisoni delta-endotoxin gene,
into the chromosome using a suicide vector system. Southern
hybridization analysis demonstrated the absence of vector
sequences, and the presence of single copies of either Tn5 or
Tn5::tox in the respective strains. Western blotting and a
bio-assay on larvae of Anopheles stephensi suggested the tox
gene was functional in clone C5t. Both D5 and C5t were
prototrophic and their generation times in minimal medium were
slightly below that of the corresponding wild-type strain. Tn
5 and Tn 5::tox were stable in both clones during growth in
minimal medium for 16 generations. During growth in
competition with the wild-type strain, D5 competed well,
however C5t was outcompeted from 50 to below 3% of the
population in 40 generations. During growth in competition in
the sterile loamy sand, both strains were outcompeted by the
parent strain; strain C5t was less competitive than D5. In
non-sterile loamy sand, the introduced mixed populations
showed a slow decline; both C5t and D5 were outcompeted by the
parent strain. The decreased fitness of both modified strains,
although significant, was considered to be small in ecological
terms. Further, the addition of 10% bentonite clay to the
loamy sand resulted in a significant enhancement of survival
of the mixed populations, and a stabilization of the
proportions between the modified strains and the parent.
Finally, there was a trend towards a decrease in the
proportion modified strain/parent strain in both mixes in the
rhizosphere of wheat.


253                                  NAL Call. No.: QH506.E46
T-DNA gene 5 of Agrobacterium modulates auxin response by
autoregulated synthesis of a growth hormone antagonist in
plants.
Korber, H.; Strizhov, N.; Staiger, D.; Feldwisch, J.; Olsson,
O.; Sandberg, G.; Palme, K.; Schell, J.; Koncz, C.
Oxford, Eng. : IRL Press; 1991 Dec.
The EMBO journal - European Molecular Biology Organization v.
10 (13): p. 3983-3991; 1991 Dec.  Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Agrobacterium tumefaciens;
Escherichia coli; Oncogenes; Promoters; Gene expression;
Genetic regulation; Tryptophan; Amino acid metabolism;
Indoles; Biosynthesis; Auxins; Antagonists; Shoots;
Regeneration; Genetic transformation; Transgenics; Molecular
mapping; Binding proteins

Abstract:  Oncogenes carried by the transferred DNA (T-DNA) of
Agrobacterium Ti plasmids encode the synthesis of plant growth
factors, auxin and cytokinin, and induce tumour development in
plants. Other T-DNA genes regulate the tumorous growth in ways
that are not yet understood. To determine the function of T-
DNA gene 5, its coding region was expressed in Escherichia
coli. Synthesis of the gene 5 encoded protein (26 kDa)
correlated with a 28-fold increase in conversion of tryptophan
to indole-3-lactate (ILA), an auxin analogue. Expression of
chimeric gene 5 constructs in transgenic tobacco resulted in
overproduction of ILA that enhanced shoot formation in
undifferentiated tissues and increased the tolerance of
germinating seedlings to the inhibitory effect of externally
supplied auxin. Promoter analysis of gene 5 in plants revealed
that its expression was inducible by auxin and confined to the
vascular phloem cells. cis-regulatory elements required for
auxin regulation and phloem specific expression of gene 5 were
mapped to a 90 bp promoter region that carried DNA sequence
motifs common to several auxin induced plant promoters, as
well as a binding site for a nuclear factor, Ax-1. ILA was
found to inhibit the auxin induction of the gene 5 promoter
and to compete with indole-3-acetic acid (IAA) for in vitro
binding to purified cellular auxin binding proteins. It is
suggested therefore that ILA autoregulates its own synthesis
and thereby modulates a number of auxin responses in plants.


254                                  NAL Call. No.: 448.3 AP5
Temperature and structural effects on transfer of double-
stranded RNA among isolates of the chestnut blight fungus
(Cryphonectria parasitica). Friese, C.F.; Allen, M.F.; Martin,
R.; Van Alfen, N.K.
Washington, D.C. : American Society for Microbiology; 1992
Jun. Applied and environmental microbiology v. 58 (6): p.
2066-2070; 1992 Jun. Includes references.

Language:  English

Descriptors: Castanea dentata; Cryphonectria parasitica; Rna;
Cytoplasm; Strains; Hyphae; Temperature

Abstract:  Cryphonectria parasitica is a unique fungus which
can serve as a model for understanding transfer of genes
between eukaryotic microorganisms. We studied transfer of
double-stranded RNA (dsRNA) between compatible and
incompatible strains of C. parasitica to determine whether
hyphal types or temperature could restrict that exchange.
Hyphal connections between incompatible strains occurred at
about 30% of the frequency of connections between compatible
strains and differed morphologically. Gel electrophoresis and
in situ hybridization confirmed that dsRNA was transferred
through substrate hyphae but not through aerial hyphae.
Freezing temperatures resulted in the loss of dsRNA from the
new mycelium of the donor colony and stimulated the production
of virulent pycnidiospores. These temperature and structural
restrictions may help to explain the lack of spread of the
dsRNA despite its presence in the field.


255                                NAL Call. No.: SB732.6.M65
Transcription of the octopine catabolism operon of the
Agrobacterium tumor-inducing plasmid pTiA6 is activated by a
LysR-type regulatory protein. Habeeb, L.F.; Wang, L.; Winans,
S.C.
St. Paul, Minn. : APS Press; 1991 Jul.
Molecular plant-microbe interactions : MPMI v. 4 (4): p.
379-385; 1991 Jul. Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Plasmids; Tumors;
Genetic regulation; Genes; Catabolism; Octopine;
Transcription; Gene expression; Nucleotide sequences; Amino
acid sequences; Genetic analysis; Molecular genetics


256                                NAL Call. No.: SB732.6.M65
Transcriptional organization and expression of the large hrp
gene cluster of Pseudomonas solanacearum.
Arlat, M.; Gough, C.L.; Zischek, C.; Barberis, P.A.; Trigalet,
A.; Boucher, C.A.
St. Paul, Minn. : APS Press; 1992 Mar.
Molecular plant-microbe interactions : MPMI v. 5 (2): p.
187-193; 1992 Mar. The accession number j0370b does not
conform to standard format.  Includes references.

Language:  English

Descriptors: Pseudomonas solanacearum; Strains; Plant
pathogenic bacteria; Genes; Pathogenicity; Genetic analysis;
Gene expression; Transcription; Size; Genetic regulation; Gene
mapping; Insertional mutagenesis; Nicotiana; Lycopersicon


257                                   NAL Call. No.: 442.8 Z8
Transfer of resistance to the beet cyst nematode (Heterodera
schachtii Schm.) into the Brassica napus L. gene pool through
intergeneric somatic hybridization with Raphanus sativus L.
Lelivelt, C.L.C.; Krens, F.A.
Berlin, W. Ger. : Springer International; 1992.
Theoretical and applied genetics v. 83 (6/7): p. 887-894;
1992.  Includes references.

Language:  English

Descriptors: Brassica napus var. oleifera; Raphanus sativus;
Intergeneric hybridization; Somatic hybridization; Restriction
fragment length polymorphism; Protoplast fusion; Direct 
DNAuptake; Genetic resistance; Heterodera schachtii;
Mitochondrial  DNA; Recombination; Mitochondrial genetics;
Chloroplast genetics; Chromosome number

Abstract:  An intergeneric somatic hybrid was obtained through
PEG-induced protoplast fusion between Brassica napus L. (oil-
seed rape, AACC, 2n = 38) and a beet cyst nematode resistant
genotype of Raphanus sativus L. (fodder radish, RR, 2n = 18).
The hybrid nature of the regenerated plant was confirmed by
flow cytometric analysis, RFLP-analysis, and chromosome
counts. Southern blot analysis of total DNA using pPhcPS1
(rbc-L) as probe indicated that the somatic hybrid contains
chloroplasts of B. napus. The mitochondrial genome of the
somatic hybrid was studied more extensively using several
probes and restriction enzymes. The results indicate inter- or
intraspecific mitochondrial DNA recombination. Resistance to
the beet cyst nematode (Heterodera schachtii Schm., BCN) was
expressed in the hybrid at a high level.


258                                  NAL Call. No.: 442.8 Z34
Transformation frequencies are enhanced and vector DNA is
targeted during retransformation of Leptosphaeria maculans, a
fungal plant pathogen. Farman, M.L.; Oliver, R.P.
Berlin, W. Ger. : Springer International; 1992 Jan.
M G G : Molecular and general genetics v. 231. (2): p.
243-247; 1992 Jan. Includes references.

Language:  English

Descriptors: Leptosphaeria maculans; Genetic transformation;
Plasmids; Vectors; Genomes; Drug resistance; Hygromycin b;
Antibiotics; Genetic markers; Protoplasts

Abstract:  Leptosphaeria maculans, a fungal pathogen of
Brassica spp., was successfully transformed with the vector
pAN8-1, encoding phleomycin resistance. Protoplasts of a
vigorous Phleo(r) transformant were then retransformed using
the partially homologous vector, pAN7-1 which encodes
hygromycin B resistance. Retransformation of this strain to
hygromycin resistance occurred at frequencies that were
consistently twofold higher than with the original recipient
strain. Linearised pAN7-1 DNA transformed phleomycin-resistant
protoplasts at higher frequencies still. All the transformants
that were tested retained a phleomycin-resistant phenotype
(20/20). Molecular analysis of five transformants generated
with circular pAN7-1 DNA indicated that in four cases the
pAN7-1 vector had integrated into pAN8-1 sequences. These
results suggest that transformation frequencies in L. maculans
are limited by the ability of vector DNA to integrate into the
genome. Hence, construction of strains with target sites for
integration may prove to be a generally useful method for
improving transformation frequencies of poorly characterised
filamentous fungi, particularly when using heterologous
vectors. This would greatly facilitate the identification of
genes by transfer of gene libraries and the standardisation of
chromosomal location effects in studies of expression of
nested promoter deletions.


259                                  NAL Call. No.: QH301.N32
Transformation of Populus--from system development to field
plantings. Klopfenstein, N.B.; Thornburg, R.W.; McNabb, H.S.
Jr; Hall, R.B.; Hart, E.R.; Chun, Y.W.; Kernan, A.; Shi, N.Q.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 357-358;
1991.  In the series analytic: Woody plant biotechnology /
edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Includes references.

Language:  English

Descriptors: Populus alba; Populus grandidentata; Hybrids;
Gene expression; Genetic transformation; Agrobacterium
tumefaciens; Disease resistance; Pest resistance


260                                   NAL Call. No.: QK600.E9
Transformation of the fungus Pyrenopeziza brassicae, cause of
light leaf spot of brassicas, and complementation of mutants
using a genomic library. Ball, A.M.; Sawczyc, M.K.; Ashby,
A.M.; Ingram, D.S.; Johnstone, K. Duluth, Minn. : Academic
Press; 1991 Sep.
Experimental mycology v. 15 (3): p. 243-254; 1991 Sep. 
Includes references.

Language:  English

Descriptors: Pyrenopeziza brassicae; Genetic transformation;
Protoplasts; Plasmids; Direct  DNAuptake; Mutants;
Complementation; Dna libraries; Pathogenicity; Leaf spotting;
Brassica campestris var. oleifera


261                                  NAL Call. No.: 448.3 J82
Transformation of the gram-positive bacterium Clavibacter xyli
subsp. cynodontis by electroporation with plasmids from the
IncP incompatibility group.
Metzler, M.C.; Zhang, Y.P.; Chen, T.A.
Washington, D.C. : American Society for Microbiology; 1992
Jul. Journal of bacteriology v. 174 (13): p. 4500-4503; 1992
Jul.  Includes references.

Language:  English

Descriptors: Clavibacter xyli; Plasmids; Genetic
transformation; Electroporation

Abstract:  We report the transformation of a gram-positive
bacterium, Clavibacter xyli subsp. cynodontis, with several
plasmids in the IncP incompatibility group from gram-negative
bacteria. Our results suggest that IncP plasmids may be
transferable to other gram-positive organisms. After
optimizing electroporation parameters, we obtained a maximum
of 2 X 10(5) transformants per microgram of DNA. The
availability of a transformation system for this bacteria will
facilitate its use in indirectly expressing beneficial traits
in plants.


262                                NAL Call. No.: SB732.6.M65
Transformation of the oomycete pathogen, Phytophthora
infestans. Judelson, H.S.; Tyler, B.M.; Michelmore, R.W.
St. Paul, Minn. : APS Press; 1991 Nov.
Molecular plant-microbe interactions : MPMI v. 4 (6): p.
602-607; 1991 Nov. Includes references.

Language:  English

Descriptors: Solanum tuberosum; Lycopersicon esculentum;
Phytophthora infestans; Plant pathogenic fungi; Genetic
transformation; Gene transfer; Vectors; Plasmids; Drug
resistance; Marker genes; Hygromycin b; Gene expression;
Pathogenicity


263                                  NAL Call. No.: 448.3 J82
Transformation of the phytopathogenic bacterium Clavibacter
michiganense subsp. michiganense by electroporation and
development of a cloning vector. Meletzus, D.; Eichenlaub, R.
Washington, D.C. : American Society for Microbiology; 1991
Jan. Journal of bacteriology v. 173 (1): p. 184-190. ill; 1991
Jan.  Includes references.

Language:  English

Descriptors: Clavibacter michiganensis subsp. michiganensis;
Genetic transformation; Electroporation; Genetic engineering

Abstract:  We constructed a cloning vector for use in the
plant pathogenic bacterium Clavibacter michiganense subsp.
michiganense. The vector pDM100 consists of a 3.2-kb
restriction fragment of the Clavibacter plasmid pCM1 joined to
a pBR325 derivative carrying the neomycin phosphotransferase
of transposon Tn5 and the gentamicin acetyltransferase of
Tn1696. Both antibiotic resistance genes are efficiently
expressed in C. michiganense subsp. michiganense. Although
polyethylene glycol-mediated transfection of spheroplasts with
the DNA of the C. michiganense subsp. michiganense-specific
bacteriophage CMP1 yielded about 3 X 10(3) transfectants per
microgram of DNA, in transformations with plasmid DNA only a
very few transformants were obtained. However, the
transformation efficiency could be improved by electroporation
of intact cells, giving about 2 X 10(3) transformants per
microgram of plasmid DNA. Since a transformation procedure and
a cloning vector are now available, pathogenicity in C.
michiganense subsp. michiganense can now be analyzed
genetically.


264                                   NAL Call. No.: QH426.C8
Transformation of Trichoderma species with dominant selectable
markers. Ulhoa, C.J.; Vainstein, M.H.; Peberdy, J.F.
Berlin, W. Ger. : Springer International; 1992.
Current genetics v. 21 (1): p. 23-26; 1992.  Includes
references.

Language:  English

Descriptors: Trichoderma hamatum; Trichoderma harzianum;
Genetic transformation; Genetic markers; Marker genes;
Escherichia coli; Phosphotransferases; Hygromycin b;
Neurospora crassa; Tubulin; Drug resistance; Fungicide
tolerance; Benomyl; Protoplasts; In vitro selection

Abstract:  We have developed a transformation system for
Trichoderma hamatum and Trichoderma harzianum Rifai, using
dominant markers for selection based on the Escherichia coli
hygromycin B phosphotransferase gene (hph) and the beta-
tubulin gene (bml) from Neurospora crassa, respectively.
Transformation frequencies and protoplast regeneration were
low in both species. All the T. hamatum hygromycin-resistant
transformants analysed were mitotically stable, in contrast to
those of T. harzianum derived by benomyl resistance, in which
only 50% of the transformants analysed were stable. Molecular
analysis of transformants showed the integration of the
transforming DNA into the genome and indicated that the number
and sites of integration varied among the transformants.


265                                   NAL Call. No.: 470 SCI2
Transgenic plants with enhanced resistance to the fungal
pathogen Rhizoctonia solani.
Broglie, K.; Chet, I.; Holliday, M.; Cressman, R.; Biddle, P.;
Knowlton, S.; Mauvais, C.J.; Broglie, R.
Washington, D.C. : American Association for the Advancement of
Science; 1991 Nov22.
Science v. 254 (5035): p. 1194-1197; 1991 Nov22.  Includes
references.

Language:  English

Descriptors: Nicotiana tabacum; Brassica; Rhizoctonia solani;
Transgenics; Genetic resistance

Abstract:  The production of enzymes capable of degrading the
cell walls of invading phytopathogenic fungi is an important
component of the defense response of plants. The timing of
this natural host defense mechanism was modified to produce
fungal-resistant plants. Transgenic tobacco seedlings
constitutively expressing a bean chitinase gene under control
of the cauliflower mosaic virus 35S promoter showed an
increased ability to survive in soil infested with the fungal
pathogen Rhizoctonia solani and delayed development of disease
symptoms.


266                                   NAL Call. No.: QH426.C8
Transient expression of genes in the oomycete Phytophthora
infestans using Bremia lactucae regulatory sequences.
Judelson, H.S.; Michelmore, R.W.
Berlin, W. Ger. : Springer International; 1991.
Current genetics v. 19 (6): p. 453-459; 1991.  Includes
references.

Language:  English

Descriptors: Bremia lactucae; Phytophthora infestans; Genetic
transformation; Gene expression; Beta-glucuronidase; Reporter
genes; Vectors; Plant pathogenic fungi

Abstract:  Vectors containing fusions between the reporter
gene beta-glucuronidase (GUS) and transcriptional regulatory
signals from the ham34 and hsp70 genes of the oomycete
pathogen, Bremia lactucae, were introduced into protoplasts of
the related fungus Phytophthora infestans. Transient
expression of the GUS gene was detected when DNA was
introduced into protoplasts of P. infestans by treatments with
polyethylene glycol and CaCl(2), with cationic liposomes, or
by electroporation. After optimization of each procedure,
using the transient expression assays, cationic liposomes were
identified as the superior method for DNA uptake. Vectors
containing the 5'hsp70 sequences and 3'ham34 sequences
resulted in the maximum level of GUS activity. The
identification of functional vectors for transformation, and
of optimal methods for introducing DNA, should assist in
achieving stable transformation of P. infestans and other
oomycete the fungi.


267                                 NAL Call. No.: 448.8 C162
Transposon Tn5-259 mutagenesis of Pseudomonas cepacia to
isolate mutants deficient in antifungal activity.
Jayaswal, R.K.; Fernandez, M.A.; Visintin, L.; Upadhyay, R.S.
Ottawa : National Research Council of Canada; 1992 Apr.
Canadian journal of microbiology v. 38 (4): p. 309-312; 1992
Apr.  Includes references.

Language:  English

Descriptors: Plant pathogenic fungi; Pseudomonas cepacia;
Mutants; Mutagenesis; Antifungal agents; Biological control
agents


268                                NAL Call. No.: SB732.6.M65
The TR-DNA region carrying the auxin synthesis genes of the
Agrobacterium rhizogenes agropine-type plasmid pRiA4:
nucleotide sequence analysis and introduction into tobacco
plants.
Camilleri, C.; Jouanin, L.
St. Paul, Minn. : APS Press; 1991 Mar.
Molecular plant-microbe interactions : MPMI v. 4 (2): p.
155-162; 1991 Mar. Includes references.

Language:  English

Descriptors: Nicotiana tabacum; Agrobacterium rhizogenes;
Genes; Auxins; Biosynthesis; Genetic regulation; Plasmids;
Nucleotide sequences; Genetic analysis; Gene expression;
Transgenics; Amino acid sequences; Comparisons; Agrobacterium
tumefaciens; Pseudomonas syringae pv. savastanoi


269                                  NAL Call. No.: 448.3 B13
Two-way chemical signaling in Agrobacterium-plant
interactions. Winans, S.C.
Washington, D.C. : American Society for Microbiology; 1992
Mar. Microbiological reviews v. 56 (1): p. 12-31; 1992 Mar. 
Literature review. Includes references.

Language:  English

Descriptors: Agrobacterium; Plant pathology; Chemotaxis;
Genetics; Dna; Gene expression; Literature reviews


270                                 NAL Call. No.: 448.3 J823
Unique DNA plasmid pRS64 associated with chromosomal DNAs of
the platn pathogenic fungus Rhizoctonia solani.
Wako, T.; Ishikawa, T.; Hashiba, T.
Reading : Society for General Microbiology; 1991 Dec.
The Journal of general microbiology v. 137 (pt.12): p.
2817-2821; 1991 Dec. Includes references.

Language:  English

Descriptors: Rhizoctonia solani; Anastomosis groups;
Chromosomes; Plasmids; Dna; Nucleotide sequences

Abstract:  Unique DNA sequences homologous to the linear DNA
plasmid pRS64 were investigated in chromosomal DNAs of
isolates belonging to anastomosis group 4 (AG-4) of the plant
pathogenic fungus Rhizoctonia solani. Chromosome-sized DNAs of
isolates RI-64 and 1271 of AG-4 were separated into six bands
by orthogonal-field-alternation gel electrophoresis and
hybridized to a cloned segment of pRS64. A small chromosome-
sized DNA band of approximately 1.1 Mb carried the sequences
homologous to pRS64 DNA. Sequences homologous to PRS64 were
also maintained within the chromosomal DNA of isolate 1271 of
AG-4 which does not possess the plasmid. The plasmid showed no
homology to the mitochondrial DNA of isolate 1271. The
possibility that the linear plasmid pRS64 may act as a
transposable genetic element is discussed.


271                                 NAL Call. No.: QH442.A1G4
The use of African cassava mosaic virus as a vector system for
plants. Meyer, P.; Heidmann, I.; Niedenhof, I.
Amsterdam : Elsevier Science Publishers; 1992.
Gene v. 110 (2): p. 213-217; 1992.  Includes references.

Language:  English

Descriptors: Nicotiana tabacum; African cassava mosaic
geminivirus; Gene transfer; Vectors; Genetic transformation;
Direct  DNAuptake; Protoplasts; Transgenics; Genomes

Abstract:  This paper describes the development of a gene-
displacement vector based on DNA1, one of two single stranded
circular genomic components of a bipartite geminivirus,
African cassava mosaic virus (ACMV). The DNA1 molecules of
ACMV were cloned as dimers into a plant transformation vector
and the constructs have been integrated into tobacco
protoplasts by PEG-mediated DNA transfer. In transgenic plants
extrachromosomal copies of DNA1 monomers could be detected.
Deletion of the coat protein-encoding gene in chimeric
constructs resulted in free DNA1 copies of reduced size, and
extrachromosomal recombinant molecules were detected after
displacement of the coat protein-encoding region by foreign
DNA fragments of comparable size. Due to the absence of the
second component of ACMV, DNA2, the transgenic plants are free
from viral infection symptoms which allows the establishment
of healthy transformants that carry a recombinant construct in
an extrachromosomal form.


272                                  NAL Call. No.: 448.3 AP5
Use of an A-T-rich DNA clone for identification and detection
of Peronosclerospora sorghi.
Yao, C.L.; Magill, C.W.; Frederiksen, R.A.
Washington, D.C. : American Society for Microbiology; 1991
Jul. Applied and environmental microbiology v. 57 (7): p.
2027-2032; 1991 Jul. Includes references.

Language:  English

Descriptors: Zea mays; Sorghum; Peronosclerospora sorghi;
Detection; Dna probes; Recombination; Plasmids; Mitochondrial 
DNA; Adenine; Thymine

Abstract:  A recombinant plasmid, pMLY12-1, screened from a
Peronosclerospora sorghi library hybridizes only to DNA of P.
sorghi, or to DNA from leaves infected with P. sorghi, not to
DNA of P. sorghi Thailand isolate, P. philippinensis, P.
sacchari, or P. maydis. The terminal sequences of the 1.3-kb
insert, which appears to contain mitochondrial DNA, are 85% A
and T. No polymorphisms were detected when the probe was
hybridized to Southern blots containing DNA from P. sorghi
pathotype 1, pathotype 3, or a Botswana isolate digested with
any of the eight restriction endonucleases tested. The banding
patterns were the same whether DNA was extracted directly from
the fungus or from infected leaves.


273                                  NAL Call. No.: 448.3 AP5
Use of bioluminescence for detection of genetically engineered
microorganisms released into the environment.
Shaw, J.J.; Dane, F.; Geiger, D.; Kloepper, J.W.
Washington, D.C. : American Society for Microbiology; 1992
Jan. Applied and environmental microbiology v. 58 (1): p.
267-273; 1992 Jan. Includes references.

Language:  English

Descriptors: Microorganisms; Genetic engineering; Environment;
Detection; Release; Xanthomonas campestris pv. campestris;
Luminescence; Application methods; Brassica oleracea var.
capitata

Abstract:  The persistence and movement of strain JS414 of
Xanthomonas campestris pv. campestris, which was genetically
engineered to bioluminesce, were monitored during a limited
field introduction. Bioluminescence and traditional dilution
plate counts were determined. Strain JS414 was applied to
cabbage plants and surrounding soil by mist inoculation, by
wound inoculation, by scattering infested debris among plants,
and by incorporating bacteria into the soil. Bioluminescent X.
campestris pv. campestris was detected in plant samples and in
the rhizosphere up to 6 weeks after inoculation. Movement to
uninoculated plants was detected on one occasion, but movement
from the immediate release area was not detected. Strain JS414
was detected in soil samples beneath mist- and wound-
inoculated plants only at intentionally infested locations and
in aerial samples only on the day of inoculation. Our
bioluminescence methods proved to be as sensitive as plating
methods for detecting the genetically engineered
microorganisms in environmental samples. Our results
demonstrate that transgenic incorporation of the LuxCDABE
operon provides a non-labor-intensive, sensitive detection
method for monitoring genetically engineered microorganisms in
nature.


274                                  NAL Call. No.: 448.3 J82
Use of cloned DNA methylase genes to increase the frequency of
transfer of foreign genes into Xanthomonas campestris pv.
malvacearum. De Feyter, R.; Gabriel, D.W.
Washington, D.C. : American Society for Microbiology; 1991
Oct. Journal of bacteriology v. 173 (20): p. 6421-6427; 1991
Oct.  Includes references.

Language:  English

Descriptors: Xanthomonas campestris pv. malvacearum; Genes;
Transferases; Dna; Clones; Plasmids; Escherichia coli; Gene
transfer; Gossypium hirsutum

Abstract:  In vitro-packaged cosmid libraries of DNA from the
bacterium Xanthomonas campestris pv. malvacearum were
restricted 200- to 1,000-fold when introduced into Mcr+
strains of Escherichia coli compared with restriction in the Mcr-
 strain HB1O1. Restriction was predominantly associated with
the mcrBC+ gene in E. coli. A plasmid (pUFR052) encoding the
XmaI and XmaIII DNA methylases was isolated from an X.
campestris pv. malvacearum library by a screening procedure
utilizing Mcr+ and Mcr- E. coli strains. Transfer of plasmids
from E. coli strains to X. campestris pv. malvacearum by
conjugation was enhanced by up to five orders of magnitude
when the donor cells contained pUFR052 as well as the plasmid
to be transferred. Subcloning of PUFR052 revealed that at
least two regions of the plasmid were required for full
modification activity. Use of such modifier plasmids is a
simple, novel method that may allow the efficient introduction
of genes into any organism in which restriction systems
provide a potent barrier to such gene transfer.


275                                 NAL Call. No.: QH431.G452
Use of double-ditelosomic and normal chromosome 1D recombinant
substitution lines to map Sr33 on chromosome arm 1DS in wheat.
Jones, S.S.; Dvorak, J.; Knott, D.R.; Qualset, C.O.
Ottawa : National Research Council of Canada; 1991 Aug.
Genome v. 34 (4): p. 505-508; 1991 Aug.  Includes references.

Language:  English

Descriptors: Triticum aestivum; Triticum; Puccinia graminis;
Gene mapping; Gene location; Chromosomes; Genes; Genetic
resistance; Rust diseases; Linkage; Gliadin; Glutenins;
Recombination; Substitution lines; Segregation; Centromeres

Abstract:  Chromosome 1D homozygous recombinant substitution
lines derived from Triticum aestivum "Chinese Spring" (cross
1) or "Chinese Spring" double-ditelosomic 1D (cross 2)
hybridized with a disomic substitution line of Triticum
tauschii chromosome 1D in "Chinese Spring" were used to
investigate the linkage relationships among Glu-D1, encoding
subunits of high molecular weight glutenin storage proteins;
Glu-D1, encoding gliadin storage proteins; Sr33, conferring
stem rust resistance; and the centromere. Based on analysis of
88 and 91 recombinant substitution lines of crosses 1 and 2,
respectively, Sr33 is tightly linked to Gli-D1 on chromosome
arm 1DS (5.6 and 7.6% recombination) and less tightly to the
centromere (29.6%, cross 2) and to Glu-D1 (40.9 and 39.5%).
The order of the loci is
Glu-D1--centromere--Sr33--Gli-D1.


276                                  NAL Call. No.: 464.8 P56
Use of monoclonal antibodies and pathogenicity tests to
characterize strains of Xanthomonas campestris pv.
dieffbachiae from aroids.
Lipp, R.L.; Alvarez, A.M.; Benedict, A.A.; Berestecky, J. St.
Paul, Minn. : American Phytopathological Society; 1992 Jun.
Phytopathology v. 82 (6): p. 677-682; 1992 Jun.  Includes
references.

Language:  English

Descriptors: Hawaii; Florida; California; Australia; Araceae;
Xanthomonas campestris pv. dieffenbachiae; Pathotypes;
Pathogenicity; Strain differences; Monoclonal antibodies; Host
range; Virulence


277                                  NAL Call. No.: 448.3 J82
The virC and virD operons of the Agrobacterium Ti plasmid are
regulated by the ros chromosomal gene: analysis of the cloned
ros gene.
Cooley, M.B.; D'Souza, M.R.; Kado, C.I.
Washington, D.C. : American Society for Microbiology; 1991
Apr. Journal of bacteriology v. 173 (8): p. 2608-2616. ill;
1991 Apr.  Includes references.

Language:  English

Descriptors: Agrobacterium tumefaciens; Amino acid sequences;
Cloning; Crown gall; Dna hybridization; Genetic regulation;
Nucleotide sequences; Plasmids; Restriction mapping; Strains;
Virulence

Abstract:  The ros chromosomal gene is present in octopine and
nopaline strains of Agrobacterium tumefaciens as well as in
Rhizobium meliloti. This gene encodes a 15.5-kda protein that
specifically represses the virC and virD operons in the
virulence region of the Ti plasmid. The ros gene was cloned
from a genomic bank by electroporation and complementation in
Agrobacterium cells. Reporter fusion to the ros gene indicates
that the level of transcription is controlled in part by
autoregulation. A consensus inverted repeat sequence present
in the ros promoter and in the virC and virD promoters of
pTiC58, pTiA6, and pRiA4b suggests that a specific Ros binding
site exists in these promoters. In the virc and virD promoter
region, this binding site is within a cluster of vir box
consensus sequences in which the VirG protein binds. This
suggests possible binding competition between Ros and VirG at
the virC and virD promoters. That the Ros protein binds DNA is
suggested by the presence of a 'zinc finger' consensus
sequence in the protein.


278                                   NAL Call. No.: 500 N21P
virF, the host-range-determining virulence gene of
Agrobacterium tumefaciens, affects T-DNA transfer to Zea mays.
Jarchow, E.; Grimsley, N.H.; Hohn, B.
Washington, D.C. : The Academy; 1991 Dec01.
Proceedings of the National Academy of Sciences of the United
States of America v. 88 (23): p. 10426-10430. ill; 1991 Dec01. 
Includes references.

Language:  English

Descriptors: Zea mays; Agrobacterium tumefaciens; Host range;
Strains; Virulence; Dna; Transfer; Maize streak geminivirus

Abstract:  The monocotyledonous plant Zea mays does not
develop tumors after inoculation with Agrobacterium
tumefaciens and is thus defined as nonhost. Agroinfection,
Agrobacterium-mediated delivery of maize streak virus,
demonstrates that transferred DNA (T-DNA) transfer to the
plant does occur. Nopaline-type Agrobacterium strains such as
C58 are efficient in the transfer process whereas the
octopine-type strain A6 is unable to transfer T-DNA to maize.
This phenotypic difference maps to the tumor-inducing (Ti)
plasmid but not to the T-DNA. Steps preceding T-DNA transfer,
such as attachment and induction of the virulence genes, were
shown to take place in the octopine strain. The nopaline-
plasmid-specific locus tzs and the
octopine-plasmid-specific locus pinF (virH) are not involved
in the strain specificity. However, mutations in the virF
locus rendered the octopine strain agroinfectious on maize,
whereas such virF-defective octopine strains, when
complemented by virF on a plasmid, completely lost their
agroinfectivity. We propose that VirF, known to increase the
host range of the bacteria in other systems, acts as an
inhibitor of T-DNA transfer to maize.


279                                  NAL Call. No.: 448.3 J82
The virulence-associated chrysobactin iron uptake system of
Erwinia chrysanthemi 3937 involves an operon encoding
transport and biosynthetic functions.
Franza, T.; Expert, D.
Washington, D.C. : American Society for Microbiology; 1991
Nov. Journal of bacteriology v. 173 (21): p. 6874-6881; 1991
Nov.  Includes references.

Language:  English

Descriptors: Erwinia chrysanthemi; Strains; Iron; Uptake;
Siderophores; Membranes; Proteins; Gene expression

Abstract:  The iron assimilation system of Erwinia
chrysanthemi 3937 is mediated by the catechol-type siderophore
chrysobactin and the outer membrane transport protein Fct. We
generated a variety of subclones in high- and low-copy-number
vectors from a wild-type recombinant cosmid shown previously
to carry the gene cluster fct-cbsA, cbsB, cbsC, cbsE encoding
chrysobactin transport and biosynthetic functions,
respectively. We studied their expression in Escherichia coli
enterobactin-deficient entA, entB, entC, and entE mutants.
This provided evidence that the fct and cbs genes are
regrouped within a single genetic unit of ca. 8 kb in the
following order: fct, cbsC, cbsE, cbsB, and cbsA. The gene
boundaries were determined, and the various recombinant
plasmids were expressed in Escherichia coli minicells: CbsA
and CbsC enzymatic activities were clearly identified as
polypeptides with apparent molecular masses of 32,000 and
38,000, respectively.


280                                 NAL Call. No.: QH442.G456
White House says recombinant organisms pose no unusual risks
to the environment.
Eisner, R.
New York, N.Y. : Mary Ann Liebert; 1992 Mar15.
Genetic engineering news v. 12 (4): p. 1, 15; 1992 Mar15.

Language:  English

Descriptors: Genetic engineering; Recombinant  DNA; Microbial
pesticides; Crops; Transgenics; Environmental impact;
Biotechnology; Environmental policy; Recombinant vaccines


281                                   NAL Call. No.: 1.9 P69P
Witches'-broom, a lethal mycoplasmal disease of lime trees in
the Sultanate of Oman and the United Arab Emirates.
Garnier, M.; Zreik, L.; Bove, J.M.
St. Paul, Minn. : American Phytopathological Society; 1991
Jun. Plant disease v. 75 (6): p. 546-551; 1991 Jun.  Includes
references.

Language:  English

Descriptors: Oman; United arab emirates; Citrus aurantiifolia;
Mycoplasma-like organisms; Mycoplasmal diseases; Spread;
Symptomatology; Disease control; Disease distribution; Disease
transmission; Etiology; Monoclonal antibodies


282                                  NAL Call. No.: QH301.N32
Wound-responsive gene expression in poplars.
Bradshaw, H.D. Jr; Gordon, M.P.
New York, N.Y. : Plenum Press; 1991.
NATO ASI series : Series A : Life sciences v. 210: p. 265-268;
1991.  In the series analytic: Woody plant biotechnology /
edited by M.R. Ahuja. Proceedings of a Workshop at the
Institute of Forest Genetics, USDA Forest Service, October
15-19, 1989, Placerville, California.  Includes references.

Language:  English

Descriptors: Populus; Gene expression; Hybrids; Injuries;
Transcription; Disease resistance; Pest resistance


283                                NAL Call. No.: SB732.6.M65
Xanthomonas campestris pv. translucens genes determining host-
specific virulence and general virulence on cereals identified
by Tn5-gusA insertion mutagenesis.
Waney, V.R.; Kingsley, M.T.; Gabriel, D.W.
St. Paul, Minn. : APS Press; 1991 Nov.
Molecular plant-microbe interactions : MPMI v. 4 (6): p.
623-627; 1991 Nov. Includes references.

Language:  English

Descriptors: Hordeum vulgare; Triticum aestivum; Avena sativa;
Triticale; Secale cereale; Gossypium hirsutum; Cultivars;
Varietal susceptibility; Xanthomonas campestris pv.
translucens; Virulence; Genes; Strains; Strain differences;
Host range; Host specificity; Genetic analysis; Insertional
mutagenesis; Induced mutations; Mutants; Complementation


284                                NAL Call. No.: 442.8 J8224
X-ray crystal structure of the two site-specific mutants
His35Gln and His35Leu of Azurin from Pseudomonas aeruginosa.
Nar, H.; Messerschmidt, A.; Huber, R.
London : Academic Press; 1991 Mar20.
Journal of molecular biology v. 218 (2): p. 427-447; 1991
Mar20.  Includes references.

Language:  English

Descriptors: Pseudomonas aeruginosa; Mutants; Plant proteins;
Induced mutations; Glutamine; Leucine; Electron transfer;
Molecular conformation; Crystals; X ray diffraction;
Crystallography

Abstract:  The three-dimensional structures of two site-
specific mutants of the blue copper protein azurin from
Pseudomonas aeruginosa have been solved by a combination of
isomorphous replacement and Patterson search techniques, and
refined by energy-restrained least-squares methods. The
mutations introduced by recombinant DNA techniques involve
residue His35, which was exchange for glutamine and leucine,
to probe for its suggested role in electron transfer. The two
mutants, His35Gln (H35Q) and His35Leu (H35L), crystallize non-
isomorphously in the orthorhombic space group P212121 with
unit cell dimensions of a = 109.74 angstrom, b = 99.15
angstrom c = 47.82 angstrom for H35Q, a = 57.82 angstrom, b =
81.06 angstrom, c = 110.03 angstrom for H35L. In each crystal
form, there are four molecules in the asymmetric unit. They
are arranged as a dimer of dimers in the H35Q case and are
distorted from ideal C2 symmetry in H35L. The final
crystallographic R-value is 16.3% for 20,747 reflections to a
resolution of 2.1 angstrom for H35Q and 17.0% for 32,548
reflections to 1.9 angstrom for H35L. The crystal structures
reported here represent the first crystallographically refined
structures for azurin from P. aeruginosa. The structure is
very similar to that of azurin from Alcaligenes denitrificans.
The copper atom is located about 7 angstrom below a
hydrophobic surface region and is ligated by five donor groups
in a distorted trigonal bipyramidal fashion. The implications
for electron transfer properties of the protein are discussed
in terms of the mutation site and the packing of the molecules
within the tetramer.
                         AUTHOR INDEX
Ahl-Goy, P.  135
Aird, E.L.H.  142
Albrecht, H.  11
Alcorn, S.C.  137
Allavena, A.  17
Allen, M.F.  254
Alton, G.  149
Alvarez, A.M.  73, 276
Amselem, J.  172
Anderson, J.B.  188
Anderson, J.J.  137
Andrianov, V.M.  216
Ankenbauer, R.G.  185
Aoyama, T.  52
Arellano, F.  107
Arlat, M.  256
Arnold, W.  130
Aronson, A.I.  246
Ashby, A.M.  88, 260
Astolfi-Filho, S.  81, 94
Atherton, G.T.  181
Ayers, A.R.  160
Aymeric, J.L.  238
Babcock, M.J.  228
Baek, S.R.  121
Bailey, A.M.  125
Bajar, A.  138
Ball, A.M.  88, 260
Banks, G.R.  43
Barash, I.  139
Barber, C.E.  119
Barberis, P.A.  256
Barbosa, P.  84
Barras, F.  238
Barta, T.M.  40
Bauer, D.W.  109
Bavage, A.D.  181
Beck von Bodman, S.  193
Beer, S.V.  95, 109
Beijersbergen, A.  45
Bej, A.K.  2
Bel, A.J.E. van  146
Bellemann, P.  161
Bender, C.L.  46, 77, 207
Benedict, A.A.  73, 276
Bennetzen, J.L.  14, 226
Bent, A.  15
Bent, A.F.  141
Berestecky, J.  276
Bergstrom, G.C.  167
Bernacchia, G.  17
Bernard, R.L.  69
Bertheau, Y.  39, 222
Best, E.A.  185
Betteridge, P.  115
Beyer, P.  25
Bhatt, D.  4
Biddle, P.  265
Binns, A.N.  3, 163
Blaiseau, P.L. A39
Blasco, F.  192
Boccara, M.  222
Boerma, H.R.  24
Bol, J.F.  11
Boller, T.  244
Bolyard, M.G.  169
Bonas, U.  96, 154
Bonde, M.R.  61
Bonnard, G.  241, 242
Boucher, C.A.  256
Bouchez, D.  196
Bouhin, H.  67
Bourson, C.  222
Bouvet, O.M.M.  143
Bove, J.M.  62, 106, 183, 281
Bozin, D.  166
Brackin, J.M.  116
Bradshaw, H.D. Jr  282
Brandes, A.  76
Brandolini, A.  127
Braun, E.J.  64
Brightwell, G.  142
Brisset, M.N.  229
Brlansky, R.H.  201
Broglie, K.  265
Broglie, R.  265
Brooker, J.D.  150
Brown, A.P.  149
Brown, J.W.  206
Brygoo, Y.  39, 108
Bulgakov, V.P.  55
Bull, J.  202
Bunkers, G.J.  97
Burns, R.  63
Burr, T.J.  136, 213, 214
Bush, A.L.  28, 54
Butterworth, J.  70
Cami, B.  238
Camilleri, C.  268
Canaday, J.  89, 156, 235, 242
Caplan, A.B.  102
Carbone, I.  188
Carland, F.M.  34
Casale, W.L.  32
Castle, L.A.  41
Caten, C.E.  153
Cerovic, G.  166
Chambost, J.P.  192
Charles, J.P.  67
Chatterjee, A.  177, 192
Chatterjee, A.K.  98, 177, 192
Chen, C.Y.  30, 49
Chen, T.A.  261
Chet, I.  265
Chiang, D.C.  36
Chilton, W.S.  247
Chiou, C.S.  12
Chiou, S.J.  36
Choudhary, A.D.  205, 250
Christ, B.J.  80
Chu, F.S.  178
Chumley, F.G.  35, 71, 180
Chun, Y.W.  259
Citovsky, V.  191
Civerolo, E.L.  211
Cizeau, J.  8
Clark, E.  139
Clausen, C.A.  51
Cleary, J.M.  162
Clements, D.  221
Close, S.M.  197
Coleman, R.H.  40
Collins, G.B.  4
Collmer, A.  98, 177, 213, 214
Cook, D.  117
Cooley, M.B.  277
Cooley, R.N.  153
Coplin, D.L.  190
Cox, G.  65
Crecy-Lagard, V. de  143
Crespi, M.  102
Cressman, R.  265
Creuzet, N.  238
Crouzet, P.  89
Crowhurst, R.N.  133
Cuppels, D.A.  26
Cutler, K.  22
D'Souza, M.R.  277
Da Costa E Silva, O.  175
Daboussi, M.J.  108, 198
Dale, E.M.  3
Dale, P.  110
Danchin, A.  143
Dane, F.  273
Daniels, M.J.  88, 119
Das, A.  48, 184, 187
Davey, M.R.  204
Davis, M.J.  75
Davis, R.E.  122
De Feyter, R.  16, 201, 274
De Quattro, J.  236
Deakin, W.  1493
Defago, G.  132
Delachambre, J.  67
Delay, D.  8
Delmotte, F.M.  8
Denes, A.S.  99
Deng, S.  123
Denny, T.P.  121
Desjardins, A.E.  151
Desomer, J.  102
Destefano-Beltran, L.  124
Dewar, K.  10
Diaz, R.  118
Dickman, M.B.  103
Dimitrijevic, B.  166
Diner, A.M.  145
Dion, P.  247
Dittapongpitch, V.  50