Publications

expression of the tomato pto gene in tobacco enhances resistance to pseudomonas syringae pv tabaci expressing avrpto.	the pto gene encodes a serine-threonine kinase that confers resistance in tomato to pseudomonas syringae pv tomato strains expressing the avirulence gene avrpto. we examined the ability of pto to function in tobacco, a species that is sexually incompatible with tomato. evidence that a heterologous pto-like signal transduction pathway is present in tobacco was suggested by the fact that tobacco line wisconsin-38 exhibits a hypersensitive response after infection with p. syringae pv tabaci express ...	1995	12242354
interference between two specific pathogen recognition events mediated by distinct plant disease resistance genes.	we demonstrate that the interaction of the avirulence gene avrrpt2 and the cognate resistance gene rps2 interferes with the interaction of avrrpm1-rpm1 in arabidopsis. interference is mediated outside of the bacterial pathogen pseudomonas syringae, presumably at the level of recognition of avr-dependent signals, yet does not require the wild-type rps2 product. a numerical excess of p. syringae expressing avrrpm1 can overcome this interference in mixed inoculations. the interference of avrrpt2-rp ...	1996	12239384
specific binding of the syringolide elicitors to a soluble protein fraction from soybean leaves.	syringolides are glycolipid elicitors produced by gram-negative bacteria expressing pseudomonas syringae avirulence gene d. the syringolides mediate gene-for-gene complementarity, inducing the hypersensitive response only in soybean plants carrying the rpg4 disease resistance gene. a site(s) for 125i-syringolide 1 was detected in the soluble protein fraction from soybean leaves, but no evidence for ligand-specific binding to the microsomal fraction was obtained. the kd value for syringolide 1 bi ...	1997	12237390
multidrug pump inhibitors uncover remarkable activity of plant antimicrobials.	plant antimicrobials are not used as systemic antibiotics at present. the main reason for this is their low level of activity, especially against gram-negative bacteria. the reported mic is often in the range of 100 to 1,000 micro g/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzl ...	2002	12234835
water relation alterations observed during hypersensitive reaction induced by bacteria.	upon exposure to pathogenic bacteria, resistant and nonhost plants undergo a hypersensitive reaction (hr) that is expressed as rapid plant cell death. if sufficient concentrations of these bacteria are inoculated to such plant tissue, then that portion of the tissue rapidly collapses and becomes necrotic. as the tissue collapses the water relations of inoculated tissues become markedly disturbed. we measured a decline in the relative water content (rwc) in the leaf-like cotyledons of cotton (gos ...	1993	12232016
volatile products of the lipoxygenase pathway evolved from phaseolus vulgaris (l.) leaves inoculated with pseudomonas syringae pv phaseolicola.	activation of the "lipoxygenase pathway" in plants gives rise to a series of products derived from fatty acids. analysis by gas chromatography-mass spectroscopy of volatile products produced by phaseolus vulgaris (l.) cv red mexican leaves during a hypersensitive resistance response (hr) to the plant pathogenic bacterium pseudomonas syringae pv phaseolicola showed evolution of several lipid-derived volatiles, including cis-3-hexenol and trans-2-hexenal, which arise from the 13-hydroperoxide of l ...	1993	12231661
systemic responses in arabidopsis thaliana infected and challenged with pseudomonas syringae pv syringae.	attack of plants by necrotizing pathogens leads to acquired resistance to the same or other pathogens in tissues adjacent to or remotely located from the site of initial attack. we have used arabidopsis thaliana inoculated with the incompatible pathogen pseudomonas syringae pv syringae on the lower leaves to test the induction of systemic reactions. when plants were challenged with pseudomonas syringae pv syringae in the upper leaves, bacterial titers remained stable in those preinfected on the ...	1995	12228548
salicylic acid in rice (biosynthesis, conjugation, and possible role).	salicylic acid (sa) is a natural inducer of disease resistance in some dicotyledonous plants. rice seedlings (oryza sativa l.) had the highest levels of sa among all plants tested for sa content (between 0.01 and 37.19 [mu]g/g fresh weight). the second leaf of rice seedlings had slightly lower sa levels than any younger leaves. to investigate the role of sa in rice disease resistance, we examined the levels of sa in rice (cv m-201) after inoculation with bacterial and fungal pathogens. sa levels ...	1995	12228500
hrp mutant of pseudomonas syringae pv phaseolicola induces cell wall alterations but not membrane damage leading to the hypersensitive reaction in lettuce.	both wild-type (s21-wt) and hrpd- (s21-533) strains of pseudomonas syringae pv phaseolicola induced the formation of large paramural papillae in lettuce (lactuca sativa) mesophyll cells adjacent to bacterial colonies. localized alterations to the plant cell wall included deposition of hydroxyproline-rich glycoproteins, phe-nolics, and callose, and were associated with proliferation of the endoplasmic reticulum and multivesicular bodies. tissue collapse during the hypersensitive reaction caused b ...	1995	12228488
a noninvasive technique for monitoring peroxidative and h2o2-scavenging activities during interactions between bacterial plant pathogens and suspension cells.	stimulation of active oxygen metabolism occurs during the early stages of interactions involving bacteria and plant cell suspensions. although many cellular processes are known to affect active oxygen metabolism in plants, it is not known which of these factors affect active oxygen levels during plant-bacteria interactions. extracellular peroxidases have been shown to participate in both the production and utilization of active oxygen species such as h2o2 and superoxide. catalase and other scave ...	1995	12228480
analysis of sweet cherry (prunus avium l.) leaves for plant signal molecules that activate the syrb gene required for synthesis of the phytotoxin, syringomycin, by pseudomonas syringae pv syringae.	an important aspect of the interaction of pseudomonas syringae pv syringae with plant hosts is the perception of plant signal molecules that regulate expression of genes, such as syrb, required for synthesis of the phytotoxin, syringomycin. in this study, the leaves of sweet cherry (prunus avium l.) were analyzed to determine the nature of the syrb-inducing activity associated with tissues of a susceptible host. crude leaf extracts yielded high amounts of total signal activity of more than 12,00 ...	1995	12228385
representational difference analysis between afa/dr diffusely adhering escherichia coli and nonpathogenic e. coli k-12.	diffusely adhering escherichia coli strains harboring afa/dr adhesins (afa/dr daec) have been associated with diarrhea and urinary tract infections (utis). the present work is the first extensive molecular study of a afa/dr daec strain using the representational difference analysis technique. we have searched for dna sequences present in strain c1845, recovered from a diarrheagenic child, but absent from a nonpathogenic k-12 strain. strain c1845 harbors part of a pathogenicity island (pai(cft073 ...	2002	12228276
characterization of an acyltransferase capable of synthesizing benzylbenzoate and other volatile esters in flowers and damaged leaves of clarkia breweri.	a cdna encoding a protein with 456 amino acids whose sequence shows considerable similarity to plant acyltransferases was identified among 750 clarkia breweri flower expressed sequence tags. the cdna was expressed in escherichia coli, and the protein produced was shown to encode the enzyme benzoyl-coenzyme a (coa):benzyl alcohol benzoyl transferase (bebt). bebt catalyzes the formation of benzylbenzoate, a minor constituent of the c. breweri floral aroma, but it also has activity with a number of ...	2002	12226525
a strobilurin fungicide enhances the resistance of tobacco against tobacco mosaic virus and pseudomonas syringae pv tabaci.	the strobilurin class of fungicides comprises a variety of synthetic plant-protecting compounds with broad-spectrum antifungal activity. in the present study, we demonstrate that a strobilurin fungicide, f 500 (pyraclostrobin), enhances the resistance of tobacco (nicotiana tabacum cv xanthi nc) against infection by either tobacco mosaic virus (tmv) or the wildfire pathogen pseudomonas syringae pv tabaci. f 500 was also active at enhancing tmv resistance in nahg transgenic tobacco plants unable t ...	2002	12226492
differential expression of a metallothionein gene during the presymbiotic versus the symbiotic phase of an arbuscular mycorrhizal fungus.	a full-length cdna encoding a metallothionein (mt)-like polypeptide, designated gmarmt1, was identified in an expressed sequence tag collection from germinated spores of the arbuscular mycorrhizal fungus gigaspora margarita (beg34). the gmarmt1 gene is composed of two exons separated by an 81-bp intron. it codes for a 65-amino acid polypeptide comprising a plant type 1 mt-like n-terminal domain and a c-terminal domain that is most closely related to an as-yet-uncharacterized fungal mt. as reveal ...	2002	12226486
a complex array of proteins related to the multimeric leucine aminopeptidase of tomato.	leucine aminopeptidase (lap) mrnas are induced in response to mechanical wounding, pathogen infection, and insect infestation (v. pautot, f.m. holzer, b. reisch, l.l. walling [1993] proc natl acad sci usa 90: 9906-9910). polyclonal antibodies to a glutathione s-transferase-lap fusion protein and affinity-purified antibodies recognizing lap antigenic determinants detected four classes of polypeptides in tomato (lycopersicon esculentum) leaves. all four classes had multiple polypeptides in two-dim ...	1996	12226257
the active oxygen response of cell suspensions to incompatible bacteria is not sufficient to cause hypersensitive cell death.	the inoculation of tobacco (nicotiana tabacum l.) suspension cells with bacterial pathogens that elicit the hypersensitive response (hr) in leaves has been shown to elicit production of active oxygen. this response occurs in two phases, the second of which occurs 1 to 3 h after bacterial addition and is unique to hr-causing interactions. the relationship between the phase ii active oxygen response and the hr was characterized using pseudomonas syringae pv syringae and p. fluorescens (phir11), wh ...	1996	12226215
salicylic acid is needed in hypersensitive cell death in soybean but does not act as a catalase inhibitor.	the function of salicylic acid (sa) in hypersensitive cell death was studied in a soybean (glycine max)-pseudomonas syringae pv glycinea system. the infection of cell cultures with bacteria leads to a hypersensitive reaction (hr), which is dependent on an appropriate avirulence gene and on low concentrations of sa. the requirement for sa is essential for a process shortly before the onset of the hr-caused cell death 5 to 6 h after infection with bacteria. sa given 10 to 12 h after infection or p ...	1997	12223807
gene-expression patterns and levels of jasmonic acid in rice treated with the resistance inducer 2,6-dichloroisonicotinic acid.	acquired disease resistance can be induced in rice (oryza sativa) by a number of synthetic or natural compounds, but the molecular mechanisms behind the phenomenon are poorly understood. one of the synthetic inducers of resistance, 2,6-dichloroisonicotinic acid (ina), efficiently protected rice leaves from infection by the rice blast fungus magnaporthe grisea (hebert) barr. a comparison of gene-expression patterns in plants treated with ina versus plants inoculated with the compatible pathogen m ...	1997	12223792
observations of ice nucleation and propagation in plants using infrared video thermography.	we evaluated the use of infrared (ir) video thermography to observe directly ice nucleation and propagation in plants. an imaging radiometer with an hgcdte long-wave (8-12 [mu]m) detector was utilized to image the thermal response of plants during freezing. ir images were analyzed in real time and recorded on videotape. information on the videotape was subsequently accessed and analyzed utilizing ir image analysis software. freezing of water droplets as small as 0.5 [mu]l was clearly detectable ...	1997	12223611
pmr6, a pectate lyase-like gene required for powdery mildew susceptibility in arabidopsis.	the plant genes required for the growth and reproduction of plant pathogens are largely unknown. in an effort to identify these genes, we isolated arabidopsis mutants that do not support the normal growth of the powdery mildew pathogen erysiphe cichoracearum. here, we report on the cloning and characterization of one of these genes, pmr6. pmr6 encodes a pectate lyase-like protein with a novel c-terminal domain. consistent with its predicted gene function, mutations in pmr6 alter the composition ...	2002	12215508
plant disease susceptibility genes?		2002	12215498
oxylipin profiling in pathogen-infected potato leaves.	plants respond to pathogen attack with a multicomponent defense response. synthesis of oxylipins via the lipoxygenase (lox) pathway appears to be an important factor for establishment of resistance in a number of pathosystems. in potato cells, pathogen-derived elicitors preferentially stimulate the 9-lox-dependent metabolism of polyunsaturated fatty acids (pufas). here we show by oxylipin profiling that potato plants react to pathogen infection with increases in the amounts of the 9-lox-derived ...	2002	12213493
identification of novel hrp-regulated genes through functional genomic analysis of the pseudomonas syringae pv. tomato dc3000 genome.	pseudomonas syringae pv. tomato (pst) strain dc3000 infects the model plants arabidopsis thaliana and tomato, causing disease symptoms characterized by necrotic lesions surrounded by chlorosis. one mechanism used by pst dc3000 to infect host plants is the type iii protein secretion system, which is thought to deliver multiple effector proteins to the plant cell. the exact number of type iii effectors in pst dc3000 or any other plant pathogenic bacterium is not known. all known type iii effector ...	2002	12207690
complete characterisation of tn5530 from burkholderia cepacia strain 2a (pijb1) and studies of 2,4-dichlorophenoxyacetate uptake by the organism.	the complete genetic characterisation of tn5530 in burkholderia cepacia strain 2a (pijb1) has been accomplished, indicating that it is a tn3-like transposon with a complex structure bearing operons for the catabolism of 2,4-dichlorophenoxyacetate (2,4-d) and malonate. tn5530 is terminated at both ends by the is1071::is1471 element and the 2,4-d- and malonate-dissimilatory operons are separated by a region encoding a puta and lrp gene and a gene encoding a chloride channel protein. the chloride c ...	2002	12206751
novel domains and orthologues of eukaryotic transcription elongation factors.	the passage of rna polymerase ii across eukaryotic genes is impeded by the nucleosome, an octamer of histones h2a, h2b, h3 and h4 dimers. more than a dozen factors in the yeast saccharomyces cerevisiae are known to facilitate transcription elongation through chromatin. in order to better understand the evolution and function of these factors, their sequences have been compared with known protein, est and dna sequences. elongator subcomplex components elp4p and elp6p are shown to be homologues of ...	2002	12202748
construction and characterization of a prou-gfp transcriptional fusion that measures water availability in a microbial habitat.	we constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. this fusion between the prou promoter from escherichia coli and the reporter gene gfp was introduced into strains of e. coli, pantoea agglomerans, and pseudomonas syringae. the prou-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of nacl, na(2)so(4), kcl, or polyethylene glycol (molecular weight, 8000 ...	2002	12200319
lipopeptide production in pseudomonas sp. strain dss73 is regulated by components of sugar beet seed exudate via the gac two-component regulatory system.	pseudomonas sp. strain dss73 isolated from the sugar beet rhizosphere produces the cyclic lipopeptide amphisin, which inhibits the growth of plant-pathogenic fungi. by tn5::luxab mutagenesis, we obtained two nonproducing mutant strains, dss73-15c2 and dss73-12h8. the gene interrupted by the transposon in strain dss73-15c2 (amsy) encoded a protein with homology to peptide synthetases that was designated amphisin synthetase. dss73-12h8 carried the transposon in a regulatory gene encoding a protein ...	2002	12200307
assessment of the importance of similarity in carbon source utilization profiles between the biological control agent and the pathogen in biological control of bacterial speck of tomato.	bacterial speck of tomato, caused by pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by ...	2002	12200291
biodegradation of the polyketide toxin cercosporin.	cercosporin is a non-host-specific polyketide toxin produced by many species of plant pathogens belonging to the genus cercospora. this red-pigmented, light-activated toxin is an important pathogenicity determinant for cercospora species. in this study, we screened 244 bacterial isolates representing 12 different genera for the ability to degrade cercosporin. cercosporin degradation was determined by screening for the presence of cleared zones surrounding colonies on cercosporin-containing cultu ...	2002	12200262
antagonism between jasmonate- and salicylate-mediated induced plant resistance: effects of concentration and timing of elicitation on defense-related proteins, herbivore, and pathogen performance in tomato.	the jasmonate (ja) and salicylate (sa) signaling pathways in plants provide resistance to herbivorous insects and pathogens. it is known that these pathways interact, sometimes resulting in antagonism between the pathways. we tested how the timing and concentration of elicitation of each pathway influenced the interaction between the jasmonate and salicylate pathways measured in terms of five biochemical responses and biological resistance to caterpillars and bacteria. the salicylate pathway had ...	2002	12184393
differential expression of genes encoding arabidopsis phospholipases after challenge with virulent or avirulent pseudomonas isolates.	phospholipase d (pld; ec 3.1.4.4) has been linked to a number of cellular processes, including tran membrane signaling and membrane degradation. four pld genes (alpha, beta, gamma1, and gamma2) have been cloned from arabidopsis thalami. they encode isoforms with distinct regulatory and catalytic properties but little is known about their physiological roles. using cdna amplified fragment length polymorphism display and rna blot analysis, we identified arabidopsis pldgamma1 and a gene encoding a ...	2002	12182338
constitutive expression of hrap gene in transgenic tobacco plant enhances resistance against virulent bacterial pathogens by induction of a hypersensitive response.	hypersensitive response-assisting protein (hrap) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpin(pss)-mediated hypersensitive response (hr). the hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. to assess the function of the hrap gene in plant disease resistance, the camv 35s promoter was used to express sweet pepper hrap in transgeni ...	2002	12182333
the phytotoxic lipodepsipeptide syringopeptin 25a from pseudomonas syringae pv syringae forms ion channels in sugar beet vacuoles.	syringopeptin 25a (sp(25)a) belongs to a family of cyclic lipodepsipeptides (ldps) produced by the gram-negative bacterium pseudomonas syringae, a phytopathogenic organism that affects several plants of agronomic interest. ldps increase the permeability of plasma and, possibly, intracellular membranes in plant cells. consistently, sp(25)a forms ion channels in planar lipid bilayers and other model membranes. here we used sugar beet tonoplasts as a new biological model system to study toxin actio ...	2002	12181614
mitochondrial alternative oxidase is not a critical component of plant viral resistance but may play a role in the hypersensitive response.	transgenic tobacco (nicotiana tabacum) with altered levels of mitochondrial alternative oxidase (aox) were used to examine the potential role of this electron transport chain protein in resistance to tobacco mosaic virus. we examined the effect of aox expression on the salicylic acid-induced resistance in susceptible plants and the resistance responses of plants harboring the n-gene. a lack of aox did not compromise the ability of salicylic acid treatment to heighten the resistance of susceptibl ...	2002	12177499
atcox17, an arabidopsis homolog of the yeast copper chaperone cox17.	we have identified a new plant gene, atcox17, encoding a protein that shares sequence similarity to cox17, a cu-binding protein from yeast (saccharomyces cerevisiae) and vertebrates that mediates the delivery of cu to the mitochondria for the assembly of a functional cytochrome oxidase complex. the newly characterized arabidopsis protein has six cys residues at positions corresponding to those known to coordinate cu binding in the yeast homolog. moreover, we show that the arabidopsis cox17 cdna ...	2002	12177498
the role of auxin, ph, and stress in the activation of embryogenic cell division in leaf protoplast-derived cells of alfalfa.	culturing leaf protoplast-derived cells of the embryogenic alfalfa (medicago sativa subsp. varia a2) genotype in the presence of low (1 microm) or high (10 microm) 2, 4-dichlorophenoxyacetic acid (2,4-d) concentrations results in different cell types. cells exposed to high 2,4-d concentration remain small with dense cytoplasm and can develop into proembryogenic cell clusters, whereas protoplasts cultured at low auxin concentration elongate and subsequently die or form undifferentiated cell colon ...	2002	12177494
nitric oxide acts as an antioxidant and delays programmed cell death in barley aleurone layers.	nitric oxide (no) is a freely diffusible, gaseous free radical and an important signaling molecule in animals. in plants, no influences aspects of growth and development, and can affect plant responses to stress. in some cases, the effects of no are the result of its interaction with reactive oxygen species (ros). these interactions can be cytotoxic or protective. because gibberellin (ga)-induced programmed cell death (pcd) in barley (hordeum vulgare cv himalaya) aleurone layers is mediated by r ...	2002	12177477
reactive oxygen species in the elongation zone of maize leaves are necessary for leaf extension.	the production and role of reactive oxygen species (ros) in the expanding zone of maize (zea mays) leaf blades were investigated. ros release along the leaf blade was evaluated by embedding intact seedlings in 2',7'-dichlorofluorescein-containing agar and examining the distribution of 2',7'-dichlorofluorescein fluorescence along leaf 4, which was exposed by removing the outer leaves before embedding the seedling. fluorescence was high in the expanding region, becoming practically non-detectable ...	2002	12177475
using genomic resources to guide research directions. the arabinogalactan protein gene family as a test case.	arabinogalactan proteins (agps) are extracellular hydroxyproline-rich proteoglycans implicated in plant growth and development. the protein backbones of agps are rich in proline/hydroxyproline, serine, alanine, and threonine. most family members have less than 40% similarity; therefore, finding family members using basic local alignment search tool searches is difficult. as part of our systematic analysis of agp function in arabidopsis, we wanted to make sure that we had identified most of the m ...	2002	12177459
in vitro freezing in microtitre plates applied to tobacco plants transformed with the inaz gene of pseudomonas syringae.	high throughput assays have been developed to measure the ice nucleation activity of transgenic tobacco, nicotiana tabacum l. cv. petit havana sr1 plants expressing the ice nucleation gene, inaz, from pseudomonas syringae at a young seedling stage, as well as in leaf tissue. both assays are carried out in 96-well microtitre plates. the first assay involves direct seeding in vitro, one seed per microtitre plate well containing murashige-skoog agar. when seedlings reach the two-leaf stage, they ar ...	2002	12177127
nitrate efflux is an essential component of the cryptogein signaling pathway leading to defense responses and hypersensitive cell death in tobacco.	there is much interest in the transduction pathways by which avirulent pathogens or derived elicitors activate plant defense responses. however, little is known about anion channel functions in this process. the aim of this study was to reveal the contribution of anion channels in the defense response triggered in tobacco by the elicitor cryptogein. cryptogein induced a fast nitrate (no(3)(-)) efflux that was sensitive to anion channel blockers and regulated by phosphorylation events and ca(2+) ...	2002	12172032
signature of balancing selection in arabidopsis.	natural selection and genetic linkage cause dna segments to have genealogical histories resembling those of the selected sites. when a polymorphism maintained by selection is old, it will have an island of enhanced sequence variability surrounding it, which represents a detectable "signature of selection." we investigate the structure of single-nucleotide polymorphisms (snps) in a 20-kb interval containing the arabidopsis thaliana disease resistance gene rps5, a locus containing common alleles f ...	2002	12172007
genetic variation for disease resistance and tolerance among arabidopsis thaliana accessions.	pathogens can be an important selective agent in plant evolution because they can severely reduce plant fitness and growth. however, the role of pathogen selection on plant evolution depends on the extent of genetic variation for resistance traits and their covariance with host fitness. although it is usually assumed that resistance traits will covary with plant fitness, this assumption has not been tested rigorously in plant-pathogen interactions. many plant species are tolerant to herbivores, ...	2002	12172004
chlorxanthomycin, a fluorescent, chlorinated, pentacyclic pyrene from a bacillus sp.	a gram-positive bacillus sp. that fluoresces yellow under long-wavelength uv light on several common culture media was isolated from soil samples. on the basis of carbon source utilization studies, fatty acid methyl ester analysis, and 16s ribosomal dna analysis, this bacterium was most similar to bacillus megaterium. chemical extraction yielded a yellow-orange fluorescent pigment, which was characterized by x-ray crystallography, mass spectrometry, and nuclear magnetic resonance spectroscopy. t ...	2002	12147512
role of pseudomonas putida indoleacetic acid in development of the host plant root system.	many plant-associated bacteria synthesize the phytohormone indoleacetic acid (iaa). while iaa produced by phytopathogenic bacteria, mainly by the indoleacetamide pathway, has been implicated in the induction of plant tumors, it is not clear whether iaa synthesized by beneficial bacteria, usually via the indolepyruvic acid pathway, is involved in plant growth promotion. to determine whether bacterial iaa enhances root development in host plants, the ipdc gene that encodes indolepyruvate decarboxy ...	2002	12147474
sequence conservation in the chagasin family suggests a common trend in cysteine proteinase binding by unrelated protein inhibitors.	the recently described inhibitor of cysteine proteinases from trypanosoma cruzi, chagasin, was found to have close homologs in several eukaryotes, bacteria and archaea, the first protein inhibitors of cysteine proteases in prokaryotes. these previously uncharacterized 110-130 residue-long proteins share a well-conserved sequence motif that corresponds to two adjacent beta-strands and the short loop connecting them. chagasin-like proteins also have other conserved, mostly aromatic, residues, and ...	2002	12142451
mutational analysis of the tola c-terminal domain of escherichia coli and genetic evidence for an interaction between tola and tolb.	the tol proteins are involved in the outer membrane stability of gram-negative bacteria. the c-terminal domain of tola was mutagenized to identify residues important for its functions. the isolation of suppressor mutants of tola mutations in the tolb gene confirmed an interaction between tolaiii and the n-terminal domain of tolb.	2002	12142433
cluster ii che genes from pseudomonas aeruginosa are required for an optimal chemotactic response.	pseudomonas aeruginosa, a gamma-proteobacterium, is motile by means of a single polar flagellum and is chemotactic to a variety of organic compounds and phosphate. p. aeruginosa has multiple homologues of escherichia coli chemotaxis genes that are organized into five gene clusters. previously, it was demonstrated that genes in cluster i and cluster v are essential for chemotaxis. a third cluster (cluster ii) contains a complete set of che genes, as well as two genes, mcpa and mcpb, encoding meth ...	2002	12142407
lon protease functions as a negative regulator of type iii protein secretion in pseudomonas syringae.	the central conserved region of the pseudomonas syringae hrp pathogenicity island encodes a type iii protein secretion system (ttss) that is required for pathogenicity in plants. expression of the hrp ttss is controlled by the alternative sigma factor, hrpl, whose expression, in turn, is positively controlled by two truncated enhancer binding proteins, hrpr and hrps. although a number of environmental conditions are known to modulate hrp ttss expression, such as stringent conditions and pathogen ...	2002	12123452
ubiquitin ligase-associated protein sgt1 is required for host and nonhost disease resistance in plants.	homologues of the yeast ubiquitin ligase-associated protein sgt1 are required for disease resistance in plants mediated by nucleotide-binding site/leucine-rich repeat (nbs-lrr) proteins. here, by silencing sgt1 in nicotiana benthamiana, we extend these findings and demonstrate that sgt1 has an unexpectedly general role in disease resistance. it is required for resistance responses mediated by nbs-lrr and other r proteins in which pathogen-derived elicitors are recognized either inside or outside ...	2002	12119413
a r2r3-myb gene, atmyb30, acts as a positive regulator of the hypersensitive cell death program in plants in response to pathogen attack.	hypersensitive response (hr) is a programmed cell death that is commonly associated with disease resistance in plants. among the different hr-related early induced genes, the atmyb30 gene is specifically, rapidly, and transiently expressed during incompatible interactions between arabidopsis and bacterial pathogens. its expression was also shown to be deregulated in arabidopsis mutants affected in the control of cell death initiation. here, we demonstrate that overexpression in arabidopsis and t ...	2002	12119395
the subtilisin-like serine protease sdd1 mediates cell-to-cell signaling during arabidopsis stomatal development.	wild-type stomata are distributed nonrandomly, and their density is controlled by endogenous and exogenous factors. in the arabidopsis mutant stomatal density and distribution1-1 (sdd1-1), the establishment of the stomatal pattern is disrupted, resulting in stomata clustering and twofold to fourfold increases in stomatal density. the sdd1 gene that encodes a subtilisin-like ser protease is expressed strongly in stomatal precursor cells (meristemoids and guard mother cells), and the sdd1 promoter ...	2002	12119372
arabidopsis son1 is an f-box protein that regulates a novel induced defense response independent of both salicylic acid and systemic acquired resistance.	one of several induced defense responses in plants is systemic acquired resistance (sar), which is regulated by salicylic acid and in arabidopsis by the nim1/npr1 protein. to identify additional components of the sar pathway or other genes that regulate sar-independent resistance, we performed genetic suppressor screens of mutagenized nim1-1 seedlings, which are highly susceptible to infection by peronospora parasitica. we isolated the son1 (suppressor of nim1-1) mutant, which shows full restora ...	2002	12119368
the presence of diverse is elements and an avrpphd homologue that acts as a virulence factor on the pathogenicity plasmid of erwinia herbicola pv. gypsophilae.	the pathogenicity of erwinia herbicola pv. gypsophilae (ehg) and erwinia herbicola pv. betae (ehb) is dependent on a native plasmid (ppath(ehg) or ppath(ehb)) that harbors the hrp gene cluster, genes encoding type iii effectors, phytohormones, biosynthetic genes, and several copies of is1327. sequence analysis of the hrp-flanking region in ppath(ehg) (cosmid pla150) revealed a cluster of four additional is elements designated as isehel, isehe2, isehe3, and isehe4. two copies of another is elemen ...	2002	12118887
overexpression of pto induces a salicylate-independent cell death but inhibits necrotic lesions caused by salicylate-deficiency in tomato plants.	tomato plants overexpressing the disease resistance gene pto (35s::pto) exhibit spontaneous cell death, accumulation of salicylic acid (sa), elevated expression of pathogenesis-related genes, and enhanced resistance to a broad range of pathogens. because salicylate plays an important role in the cell death and defense activation in many lesion mimic mutants, we investigated the interaction of sa-mediated processes and the 35s::pto-mediated defense pathway by introducing the nahg transgene that e ...	2002	12118881
the role of ethylene and wound signaling in resistance of tomato to botrytis cinerea.	ethylene, jasmonate, and salicylate play important roles in plant defense responses to pathogens. to investigate the contributions of these compounds in resistance of tomato (lycopersicon esculentum) to the fungal pathogen botrytis cinerea, three types of experiments were conducted: (a) quantitative disease assays with plants pretreated with ethylene, inhibitors of ethylene perception, or salicylate; (b) quantitative disease assays with mutants or transgenes affected in the production of or the ...	2002	12114587
effect of yeast cta1 gene expression on response of tobacco plants to tobacco mosaic virus infection.	the response of tobacco (nicotiana tabacum l. cv xanthi-nc) plants with elevated catalase activity was studied after infection by tobacco mosaic virus (tmv). these plants contain the yeast (saccharomyces cerevisiae) peroxisomal catalase gene cta1 under the control of the cauliflower mosaic virus 35s promoter. the transgenic lines exhibited 2- to 4-fold higher total in vitro catalase activity than untransformed control plants under normal growth conditions. cellular localization of the cta1 prote ...	2002	12114558
rsma and the quorum-sensing signal, n-[3-oxohexanoyl]-l-homoserine lactone, control the levels of rsmb rna in erwinia carotovora subsp. carotovora by affecting its stability.	rsma (for regulator of secondary metabolism), rsmc, and rsmb rna, the components of a posttranscriptional regulatory system, control extracellular protein production and pathogenicity in erwinia carotovora subsp. carotovora. rsma, an rna binding protein, acts as a negative regulator by promoting message decay. rsmb rna, on the other hand, acts as a positive regulator by neutralizing the effect of rsma. rsmc modulates the levels of rsma and rsmb rna by positively regulating rsma and negatively co ...	2002	12107125
phytochrome signalling modulates the sa-perceptive pathway in arabidopsis.	the interaction of phytochrome signalling with the sa signal transduction pathway has been investigated in arabidopsis using single and multiple mutants affected in light perception (phya and phyb deficient) and light-signal processing (psi2, phytochrome signalling). the induction of pr1 by sa and functional analogues has been found to strictly correlate with the activity of the signalling pathway controlled by both phya and phyb photoreceptors. in darkness as well as dim light, and independentl ...	2002	12100485
induced systemic resistance (isr) against pathogens in the context of induced plant defences.	induced systemic resistance (isr) of plants against pathogens is a widespread phenomenon that has been intensively investigated with respect to the underlying signalling pathways as well as to its potential use in plant protection. elicited by a local infection, plants respond with a salicylic-dependent signalling cascade that leads to the systemic expression of a broad spectrum and long-lasting disease resistance that is efficient against fungi, bacteria and viruses. changes in cell wall compos ...	2002	12099523
lymphopenia in the bb rat model of type 1 diabetes is due to a mutation in a novel immune-associated nucleotide (ian)-related gene.	the bb (biobreeding) rat is one of the best models of spontaneous autoimmune diabetes and is used to study non-mhc loci contributing to type 1 diabetes. type 1 diabetes in the diabetes-prone bb (bbdp) rat is polygenic, dependent upon mutations at several loci. iddm1, on chromosome 4, is responsible for a lymphopenia (lyp) phenotype and is essential to diabetes. in this study, we report the positional cloning of the iddm1/lyp locus. we show that lymphopenia is due to a frameshift deletion in a no ...	2002	12097339
altering plant-microbe interaction through artificially manipulating bacterial quorum sensing.	many bacteria regulate diverse physiological processes in concert with their population size. bacterial cell-to-cell communication utilizes small diffusible signal molecules, which the bacteria both produce and perceive. the bacteria couple gene expression to cell density by eliciting a response only when the signalling molecules reach a critical threshold (a point at which the population is said to be 'quorate'). the population as a whole is thus able to modify its behaviour as a single unit. a ...	2002	12096736
[activity of toxins produced by pseudomonas syringae pv. syringae in model and cell membranes].	we studied effects of toxins produced by a bacterium pseudomonas syringae pv. syringae on the conductance of bilayer lipid membranes (blm). the used toxins were as follows: syringopeptin 22a (sp22a), syringomycin e (spe), syringostatin a (ssa), syringotoxin b (stb), and methylated syringomycin e (ch3-sre). all toxins demonstrated channel-forming activity. the threshold sequence for toxin activity was sp22a > sre approximately equal to ssa > stb > ch3-sre, and this sequence was independent of lip ...	2002	12094768
evidence of association of salmonellae with tomato plants grown hydroponically in inoculated nutrient solution.	the possibility of uptake of salmonellae by roots of hydroponically grown tomato plants was investigated. within 1 day of exposure of plant roots to hoagland nutrient solution containing 4.46 to 4.65 log(10) cfu of salmonellae/ml, the sizes of the pathogen populations were 3.01 cfu/g of hypocotyls and cotyledons and 3.40 log(10) cfu/g of stems for plants with intact root systems (control) and 2.55 log(10) cfu/g of hypocotyls and cotyledons for plants from which portions of the roots had been rem ...	2002	12089054
fitness of salmonella enterica serovar thompson in the cilantro phyllosphere.	the epiphytic fitness of salmonella enterica was assessed on cilantro plants by using a strain of s. enterica serovar thompson that was linked to an outbreak resulting from cilantro. salmonella serovar thompson had the ability to colonize the surface of cilantro leaves, where it was detected by confocal laser scanning microscopy (clsm) at high densities on the veins and in natural lesions. the population sizes of two common colonizers of plant surfaces, pantoea agglomerans and pseudomonas chloro ...	2002	12089050
genotypic and phenotypic diversity within species of purple nonsulfur bacteria isolated from aquatic sediments.	to assess the extent of genotypic and phenotypic diversity within species of purple nonsulfur bacteria found in aquatic sediments, a total of 128 strains were directly isolated from agar plates that had been inoculated with sediment samples from haren and de biesbosch in the netherlands. all isolates were initially characterized by box-pcr genomic dna fingerprinting, and 60 distinct genotypes were identified. analyses of 16s rrna gene sequences of representatives of each genotype showed that fiv ...	2002	12089030
plant-dependent genotypic and phenotypic diversity of antagonistic rhizobacteria isolated from different verticillium host plants.	to study the effect of plant species on the abundance and diversity of bacterial antagonists, the abundance, the phenotypic diversity, and the genotypic diversity of rhizobacteria isolated from potato, oilseed rape, and strawberry and from bulk soil which showed antagonistic activity towards the soilborne pathogen verticillium dahliae kleb. were analyzed. rhizosphere and soil samples were taken five times over two growing seasons in 1998 and 1999 from a randomized field trial. bacterial isolates ...	2002	12089011
survival of gacs/gaca mutants of the biological control bacterium pseudomonas aureofaciens 30-84 in the wheat rhizosphere.	gacs/gaca comprises a two-component regulatory system that controls the expression of secondary metabolites required for the control of plant diseases in many pseudomonads. high mutation frequencies of gacs and gaca have been observed in liquid culture. we examined whether gacs/gaca mutants could competitively displace the wild-type populations on roots and thus pose a threat to the efficacy of biological control. the survival of a gac mutant alone and in competition with the wild type on roots ...	2002	12089008
cloning and heterologous expression of an enantioselective amidase from rhodococcus erythropolis strain mp50.	the gene for an enantioselective amidase was cloned from rhodococcus erythropolis mp50, which utilizes various aromatic nitriles via a nitrile hydratase/amidase system as nitrogen sources. the gene encoded a protein of 525 amino acids which corresponded to a protein with a molecular mass of 55.5 kda. the deduced complete amino acid sequence showed homology to other enantioselective amidases from different bacterial genera. the nucleotide sequence approximately 2.5 kb upstream and downstream of t ...	2002	12089004
two immediate-early pathogen-responsive members of the atcmpg gene family in arabidopsis thaliana and the w-box-containing elicitor-response element of atcmpg1.	the arabidopsis thaliana genome contains at least 50 predicted atcmpg genes. the encoded protein family is defined by a common domain possessing four strictly conserved amino acid residues [cys, met, pro, and gly (cmpg)] that designate the family. two members, atcmpg1 and atcmpg2, with high sequence similarity to the previously described, immediate-early pathogen-responsive pccmpg1 gene from petroselinum crispum were selected for analysis of their expression modes and defense-related promoter el ...	2002	12084942
in vivo interaction between npr1 and transcription factor tga2 leads to salicylic acid-mediated gene activation in arabidopsis.	the arabidopsis npr1 protein is a key regulator of salicylic acid (sa)-mediated gene expression in systemic acquired resistance. based on yeast two-hybrid analysis, npr1 has been suggested to interact with members of the tga family of transcription factors, including tga2 (ahbp-1b). however, genetic evidence demonstrating that the npr1-tga interaction occurs in planta is still lacking, and the role of this interaction in sa-mediated gene activation has yet to be determined. in this study, we exp ...	2002	12084833
burkholderia thailandensis e125 harbors a temperate bacteriophage specific for burkholderia mallei.	burkholderia thailandensis is a nonpathogenic gram-negative bacillus that is closely related to burkholderia mallei and burkholderia pseudomallei. we found that b. thailandensis e125 spontaneously produced a bacteriophage, termed phie125, which formed turbid plaques in top agar containing b. mallei atcc 23344. we examined the host range of phie125 and found that it formed plaques on b. mallei but not on any other bacterial species tested, including b. thailandensis and b. pseudomallei. examinati ...	2002	12081973
the barley stem rust-resistance gene rpg1 is a novel disease-resistance gene with homology to receptor kinases.	stem rust caused by puccinia graminis f. sp. tritici was among the most devastating diseases of barley in the northern great plains of the u.s. and canada before the deployment of the stem rust-resistance gene rpg1 in 1942. since then, rpg1 has provided durable protection against stem rust losses in widely grown barley cultivars (cvs.). extensive efforts to clone rpg1 by synteny with rice provided excellent flanking markers but failed to yield the gene because it does not seem to exist in rice. ...	2002	12077318
role of salicylic acid and nim1/npr1 in race-specific resistance in arabidopsis.	salicylic acid (sa) and the nim1/npr1 protein have both been demonstrated to be required for systemic acquired resistance (sar) and implicated in expression of race-specific resistance. in this work, we analyzed the role that each of these molecules play in the resistance response triggered by members of two subclasses of resistance (r) genes, members of which recognize unrelated pathogens. we tested the ability of tir and coiled-coil-class (also known as leucine-zipper-class) r genes to confer ...	2002	12072475
potentiation of developmentally regulated plant defense response by atwrky18, a pathogen-induced arabidopsis transcription factor.	atwrky18 is a pathogen- and salicylic acid-induced arabidopsis transcription factor containing the plant-specific wrky zinc finger dna-binding motif. in the present study, we have transformed arabidopsis plants with atwrky18 under control of the cauliflower mosaic virus 35s promoter. surprisingly, transgenic plants expressing high levels of atwrky18 were stunted in growth. when expressed at moderate levels, atwrky18 potentiated developmentally regulated defense responses in transgenic plants wit ...	2002	12068113
transcriptional profiling reveals novel interactions between wounding, pathogen, abiotic stress, and hormonal responses in arabidopsis.	mechanical wounding not only damages plant tissues, but also provides pathways for pathogen invasion. to understand plant responses to wounding at a genomic level, we have surveyed the transcriptional response of 8,200 genes in arabidopsis plants. approximately 8% of these genes were altered by wounding at steady-state mrna levels. studies of expression patterns of these genes provide new information on the interactions between wounding and other signals, including pathogen attack, abiotic stres ...	2002	12068110
signals involved in arabidopsis resistance to trichoplusia ni caterpillars induced by virulent and avirulent strains of the phytopathogen pseudomonas syringae.	plants have evolved different but interconnected strategies to defend themselves against herbivorous insects and microbial pathogens. we used an arabidopsis/pseudomonas syringae pathosystem to investigate the impact of pathogen-induced defense responses on cabbage looper (trichoplusia ni) larval feeding. arabidopsis mutants [npr1, pad4, eds5, and sid2(eds16)] or transgenic plants (nahg) that are more susceptible to microbial pathogens and are compromised in salicylic acid (sa)-dependent defense ...	2002	12068100
the shca protein is a molecular chaperone that assists in the secretion of the hoppsya effector from the type iii (hrp) protein secretion system of pseudomonas syringae.	pseudomonas syringae uses a type iii protein secretion system encoded by the hrp pathogenicity island (pai) to translocate effector proteins into plant cells. one of these effector proteins is hoppsya. a small open reading frame (orf), named shca, precedes the hoppsya gene in the hrp pai of p. s. syringae 61. the predicted amino acid sequence of shca shares general characteristics with chaperones used in type iii protein secretion systems of animal pathogens. a functionally non-polar deletion of ...	2002	12067337
two distinct pseudomonas effector proteins interact with the pto kinase and activate plant immunity.	the pto serine/threonine kinase of tomato confers resistance to speck disease by recognizing strains of pseudomonas syringae that express the protein avrpto. pto and avrpto physically interact, and this interaction is required for activation of host resistance. we identified a second pseudomonas protein, avrptob, that interacts specifically with pto and is widely distributed among plant pathogens. avrptob is delivered into the plant cell by the bacterial type iii secretion system, and it elicits ...	2002	12062102
an evolutionarily conserved mediator of plant disease resistance gene function is required for normal arabidopsis development.	plants recognize many pathogens through the action of a diverse family of proteins called disease resistance (r) genes. the arabidopsis r gene rpm1 encodes resistance to specific pseudomonas syringae strains. we describe an rpm1-interacting protein that is an ortholog of tip49a, previously shown to interact with the tata binding protein (tbp) complex and to modulate c-myc- and beta-catenin-mediated signaling in animals. reduction of arabidopsis tip49a (attip49a) mrna levels results in measurable ...	2002	12062092
inhibition of bacterial ice nucleation by polyglycerol polymers.	the simple linear polymer polyglycerol (pgl) was found to apparently bind and inhibit the ice nucleating activity of proteins from the ice nucleating bacterium pseudomonas syringae. pgl of molecular mass 750 da was added to a solution consisting of 1 ppm freeze-dried p. syringae 31a in water. differential ice nucleator spectra were determined by measuring the distribution of freezing temperatures in a population of 98 drops of 1 microl volume. the mean freezing temperature was lowered from -6.8 ...	2002	12061844
direct biochemical evidence for type iii secretion-dependent translocation of the avrbs2 effector protein into plant cells.	the calmodulin-dependent adenylate cyclase domain (cya) of the bordetella pertussis cyclolysin was used as a reporter protein to study the direct translocation of the xanthomonas effector protein, avrbs2, into the plant host cell. adenylate cyclase activity (production of camp) depends on the presence of eukaryotic plant calmodulin and is only active after translocation from the prokaryotic cell into the eukaryotic plant cell. here, we show that infection of pepper plants by xanthomonas campestr ...	2002	12060777
characterization of an ethylene-induced esterase gene isolated from citrus sinensis by competitive hybridization.	a simple new method, competitive hybridization, for identification of differentially regulated genes was used to isolate novel genes induced by ethylene in citrus (citrus sinensis [l.] osbeck cv. shamouti) leaves. one of the isolated genes, an ethylene-induced esterase gene (eie), was further characterized. the deduced protein sequence of this gene shows a similarity to those of several plant alpha/beta hydrolase gene family members, which are known to be involved in secondary metabolism. northe ...	2001	12060305
constitutive expression of ethylene-response-factor1 in arabidopsis confers resistance to several necrotrophic fungi.	infection of a plant by a pathogen induces a variety of defense responses that imply the action of several signaling molecules, including salicylic acid (sa), jasmonic acid (ja) and ethylene (e). here we describe the role of ethylene-response-factor1 (erf1) as a regulator of ethylene responses after pathogen attack in arabidopsis. the erf1 transcript is induced on infection by botrytis cinerea, and overexpression of erf1 in arabidopsis is sufficient to confer resistance to necrotrophic fungi suc ...	2002	12060224
characterization of arabidopsis enhanced disease susceptibility mutants that are affected in systemically induced resistance.	in arabidopsis, the rhizobacterial strain pseudomonas fluorescens wcs417r triggers jasmonate (ja)- and ethylene (et)-dependent induced systemic resistance (isr) that is effective against different pathogens. arabidopsis genotypes unable to express rhizobacteria-mediated isr against the bacterial pathogen pseudomonas syringae pv. tomato dc3000 (pst dc3000) exhibit enhanced disease susceptibility towards this pathogen. to identify novel components controlling induced resistance, we tested 11 arabi ...	2002	12060223
structure of the o-polysaccharide of pseudomonas syringae pv. delphinii ncppb 1879(t) having side chains of 3-acetamido-3,6-dideoxy-d-galactose residues.	the o-polysaccharide (ops) was obtained from the lipopolysaccharide of pseudomonas syringae pv. delphinii ncppb 1879(t) and studied by sugar and methylation analyses, smith degradation, and (1)h- and (13)c-nmr spectroscopy. the ops was found to contain residues of l-rhamnose (l-rha) and 3-acetamido-3,6-dideoxy-d-galactose (d-fuc3nac), and the following structure of the major (n = 2) and minor (n = 3) heptasaccharide repeating units of the ops was established: [carbohydrate structure: see text]. ...	2002	12059776
nhl25 and nhl3, two ndr1/hin1-1ike genes in arabidopsis thaliana with potential role(s) in plant defense.	the arabidopsis genome contains 28 genes with sequence homology to the arabidopsis ndr1 gene and the tobacco hin1 gene. expression analysis of eight of these genes identified two (nhl25 and nhl3 for ndr1/hin1-like) that show pathogen-dependent mrna accumulation. transcripts did not accumulate during infection with virulent pseudomonas syringae pv. tomato dc3000 but did accumulate specifically when the bacteria carried any of the four avirulence genes avrrpm1, avrrpt2, avrb, or avrrps4. furthermo ...	2002	12059109
characterization of a novel, defense-related arabidopsis mutant, cir1, isolated by luciferase imaging.	in order to identify components of the defense signaling network engaged following attempted pathogen invasion, we generated a novel pr-1::luciferase (luc) transgenic line that was deployed in an imaging-based screen to uncover defense-related mutants. the recessive mutant designated cir1 exhibited constitutive expression of salicylic acid (sa), jasmonic acid (ja)/ethylene, and reactive oxygen intermediate-dependent genes. moreover, this mutation conferred resistance against the bacterial pathog ...	2002	12059104
ppi1: a novel pathogen-induced basic region-leucine zipper (bzip) transcription factor from pepper.	we have isolated a full-length cdna, ppi1 (pepper-pmmv interaction 1), encoding a novel basic region-leucine zipper (bzip) dna-binding protein, from expressed sequence tags differentially expressed in capsicum chinense p1257284 infected with pepper mild mottle virus (pmmv). ppi1 encodes a predicted protein of 170 amino acids and contains a putative dna-binding domain that shares significant amino acid identity with acgt-binding domains of members of the bzip dna-binding protein family. ppi1 was ...	2002	12059102
the jasmonate signal pathway.		2002	12045275
ethylene biosynthesis and signaling networks.		2002	12045274
specificity and cross-talk in plant signal transduction: january 2002 keystone symposium.		2002	12045267
siderophore typing, a powerful tool for the identification of fluorescent and nonfluorescent pseudomonads.	a total of 301 strains of fluorescent pseudomonads previously characterized by conventional phenotypic and/or genomic taxonomic methods were analyzed through siderotyping, i.e., by the isoelectrophoretic characterization of their main siderophores and pyoverdines and determination of the pyoverdine-mediated iron uptake specificity of the strains. as a general rule, strains within a well-circumscribed taxonomic group, namely the species pseudomonas brassicacearum, pseudomonas fuscovaginae, pseudo ...	2002	12039729
protection of tomato seedlings against infection by pseudomonas syringae pv. tomato by using the plant growth-promoting bacterium azospirillum brasilense.	pseudomonas syringae pv. tomato, the causal agent of bacterial speck of tomato, and the plant growth-promoting bacterium azospirillum brasilense were inoculated onto tomato plants, either alone, as a mixed culture, or consecutively. the population dynamics in the rhizosphere and foliage, the development of bacterial speck disease, and their effects on plant growth were monitored. when inoculated onto separate plants, the a. brasilense population in the rhizosphere of tomato plants was 2 orders o ...	2002	12039714
rar1 and ndr1 contribute quantitatively to disease resistance in arabidopsis, and their relative contributions are dependent on the r gene assayed.	plant disease resistance (r) genes mediate specific pathogen recognition, leading to a successful immune response. downstream responses include ion fluxes, an oxidative burst, transcriptional reprogramming, and, in many cases, hypersensitive cell death at the infection site. we used a transgenic arabidopsis line carrying the bacterial avirulence gene avrrpm1 under the control of a steroid-inducible promoter to select for mutations in genes required for rpm1-mediated recognition and signal transd ...	2002	12034893
arabidopsis sgt1b is required for defense signaling conferred by several downy mildew resistance genes.	we describe the identification of a mutant in the arabidopsis accession columbia (col-0) that exhibits enhanced downy mildew (edm1) susceptibility to several peronospora parasitica isolates, including the rpp7-diagnostic isolate hiks1. the mutation was mapped to chromosome iv and characterized physically as a 35-kb deletion spanning seven genes. one of these genes complemented the mutant to full wild-type resistance against all of the peronospora isolates tested. this gene (atsgt1b) encodes a pr ...	2002	12034892
arabidopsis rar1 exerts rate-limiting control of r gene-mediated defenses against multiple pathogens.	we have identified the arabidopsis ortholog of barley rar1 as a component of resistance specified by multiple nucleotide binding/leu-rich repeat resistance (r) genes recognizing different bacterial and oomycete pathogen isolates. characterization of partially and fully defective rar1 mutations revealed that wild-type rar1 acts as a rate-limiting regulator of early r gene-triggered defenses, determining the extent of pathogen containment, hypersensitive plant cell death, and an oxidative burst at ...	2002	12034891
a novel type of conserved dna-binding domain in the transcriptional regulators of the algr/agra/lytr family.	sequence analysis of bacterial genomes revealed a novel dna-binding domain. this domain is found in several response regulators of the two-component signal transduction system, such as pseudomonas aeruginosa algr, involved in the regulation of alginate biosynthesis and in the pathogenesis of cystic fibrosis; clostridium perfringens virr, a regulator of virulence factors, and in several regulators of bacteriocin biosynthesis, previously unified in the agra/come family. most of the transcriptional ...	2002	12034833
biological control of pseudomonas syringae pv. glycinea by epiphytic bacteria under field conditions.	the efficacy of a bacterial strain as a biocontrol agent in the field may be related to the ecological similarity between the biocontrol agent and the target pathogen. therefore, a number of different pseudomonas syringae strains were evaluated for their antagonistic activities in vitro (agar-diffusion assay) and in planta (greenhouse assay) against the target pathogen, pseudomonas syringae pv. glycinea. six strains of five different pathovars were found to be antagonistic in vitro as well as in ...	2001	12032618