Publications

pyoverdine-mediated iron uptake in pseudomonas aeruginosa: the tat system is required for pvdn but not for fpva transport.	under iron-limiting conditions, pseudomonas aeruginosa pao1 secretes a fluorescent siderophore called pyoverdine (pvd). after chelating iron, this ferric siderophore is transported back into the cells via the outer membrane receptor fpva. the pvd-dependent iron uptake pathway requires several essential genes involved in both the synthesis of pvd and the uptake of ferric pvd inside the cell. a previous study describing the global phenotype of a tat-deficient p. aeruginosa strain showed that the d ...	2006	16621825
a plant mirna contributes to antibacterial resistance by repressing auxin signaling.	plants and animals activate defenses after perceiving pathogen-associated molecular patterns (pamps) such as bacterial flagellin. in arabidopsis, perception of flagellin increases resistance to the bacterium pseudomonas syringae, although the molecular mechanisms involved remain elusive. here, we show that a flagellin-derived peptide induces a plant microrna (mirna) that negatively regulates messenger rnas for the f-box auxin receptors tir1, afb2, and afb3. repression of auxin signaling restrict ...	2006	16627744
role of nucleotide excision repair and photoreactivation in the solar uvb radiation survival of pseudomonas syringae pv. syringae b728a.	to assess the role of dna repair and photoreactivation in the solar radiation survival of the plant pathogen and leaf surface epiphyte pseudomonas syringae pv. syringae (pss).	2006	16630008
insect-antifeedant and antibacterial activity of diterpenoids from species of plectranthus.	bio-assay guided fractionation of an acetone extract of leaf material from plectranthus saccatus benth. resulted in the isolation of a beyerane diterpenoid. this compound, characterised by spectroscopic methods as ent-3beta-(3-methyl-2-butenoyl)oxy-15-beyeren-19-oic acid, showed insect antifeedant activity against spodoptera littoralis. known quinonoid abietane diterpenoids obtained from new sources included a mixture of the (4r,19r) and (4r,19s) diastereoisomers of coleon a from p. aff. puberul ...	2006	16631828
intermolecular transfer of copper ions from the copc protein of pseudomonas syringae. crystal structures of fully loaded cu(i)cu(ii) forms.	copc is a small soluble protein expressed in the periplasm of pseudomonas syringae pathovar tomato as part of its copper resistance response (cop operon). equilibrium competition reactions confirmed two separated binding sites with high affinities for cu(i) (10(-7) > or = k(d) > or = 10(-13) m) and cu(ii) (k(d) = 10(-13(1)) m), respectively. while cu(i)-copc was converted cleanly by o2 to cu(ii)-copc, the fully loaded form cu(i)cu(ii)-copc was stable in air. variant forms h1f and h91f exhibited ...	2006	16637653
the genome of rhizobium leguminosarum has recognizable core and accessory components.	rhizobium leguminosarum is an alpha-proteobacterial n2-fixing symbiont of legumes that has been the subject of more than a thousand publications. genes for the symbiotic interaction with plants are well studied, but the adaptations that allow survival and growth in the soil environment are poorly understood. we have sequenced the genome of r. leguminosarum biovar viciae strain 3841.	2006	16640791
fitness benefits of systemic acquired resistance during hyaloperonospora parasitica infection in arabidopsis thaliana.	we investigated the fitness benefits of systemic acquired resistance (sar) in arabidopsis thaliana using a mutational and transformational genetic approach. genetic lines were designed to differ in the genes determining resistance signaling in a common genetic background. two mutant lines (cpr1 and cpr5) constitutively activate sar at different points in sar signaling, and one mutant line (npr1) has impaired sar. the transgenic line (npr1-h) has enhanced resistance when sar is activated, but sar ...	2006	16648642
dual detection of fungal infections in drosophila via recognition of glucans and sensing of virulence factors.	the drosophila immune system discriminates between various types of infections and activates appropriate signal transduction pathways to combat the invading microorganisms. the toll pathway is required for the host response against fungal and most gram-positive bacterial infections. the sensing of gram-positive bacteria is mediated by the pattern recognition receptors pgrp-sa and gnbp1 that cooperate to detect the presence of infections in the host. here, we report that gnbp3 is a pattern recogn ...	2006	17190605
type iii effector diversification via both pathoadaptation and horizontal transfer in response to a coevolutionary arms race.	the concept of the coevolutionary arms race holds a central position in our understanding of pathogen-host interactions. here we identify the molecular mechanisms and follow the stepwise progression of an arms race in a natural system. we show how the evolution and function of the hopz family of type iii secreted effector proteins carried by the plant pathogen pseudomonas syringae are influenced by a coevolutionary arms race between pathogen and host. we surveyed 96 isolates of p. syringae and i ...	2006	17194219
phytotoxicity and innate immune responses induced by nep1-like proteins.	we show that oomycete-derived nep1 (for necrosis and ethylene-inducing peptide1)-like proteins (nlps) trigger a comprehensive immune response in arabidopsis thaliana, comprising posttranslational activation of mitogen-activated protein kinase activity, deposition of callose, production of nitric oxide, reactive oxygen intermediates, ethylene, and the phytoalexin camalexin, as well as cell death. transcript profiling experiments revealed that nlps trigger extensive reprogramming of the arabidopsi ...	2006	17194768
a bifunctional o-glcnac transferase governs flagellar motility through anti-repression.	flagellar motility is an essential mechanism by which bacteria adapt to and survive in diverse environments. although flagella confer an advantage to many bacterial pathogens for colonization during infection, bacterial flagellins also stimulate host innate immune responses. consequently, many bacterial pathogens down-regulate flagella production following initial infection. listeria monocytogenes is a facultative intracellular pathogen that represses transcription of flagellar motility genes at ...	2006	17158746
thermo-responsive expression and differential secretion of the extracellular enzyme levansucrase in the plant pathogenic bacterium pseudomonas syringae pv. glycinea.	in the plant pathogen pseudomonas syringae, production of the exopolysaccharide levan is mediated by extracellular levansucrase (lsc), which is encoded by two functional genes, lscb and lscc. comparison of extracellular protein profiles of p. syringae pv. glycinea pg4180 grown at 18 and 28 degrees c and western blots revealed that lsc was predominantly found in the supernatant at 18 degrees c, a temperature fostering virulence of this pathogen. northern blot analysis indicated that transcription ...	2006	17147762
rar1, a central player in plant immunity, is targeted by pseudomonas syringae effector avrb.	pathogenic bacterial effectors suppress pathogen-associated molecular pattern (pamp)-triggered host immunity, thereby promoting parasitism. in the presence of cognate resistance genes, it is proposed that plants detect the virulence activity of bacterial effectors and trigger a defense response, referred to here as effector-triggered immunity (eti). however, the link between effector virulence and eti at the molecular level is unknown. here, we show that the pseudomonas syringae effector avrb su ...	2006	17148606
a ferroxidation/permeation iron uptake system is required for virulence in ustilago maydis.	in the smut fungus ustilago maydis, a tightly regulated camp signaling cascade is necessary for pathogenic development. transcriptome analysis using whole genome microarrays set up to identify putative target genes of the protein kinase a catalytic subunit adr1 revealed nine genes with putative functions in two high-affinity iron uptake systems. these genes locate to three gene clusters on different chromosomes and include the previously identified complementing siderophore auxotroph genes sid1 ...	2006	17138696
protein polyubiquitination plays a role in basal host resistance of barley.	to study protein ubiquitination pathways in the interaction of barley (hordeum vulgare) with the powdery mildew fungus (blumeria graminis), we measured protein turnover and performed transient-induced gene silencing (tigs) of ubiquitin and 26s proteasome subunit encoding genes in epidermal cells. attack by b. graminis hyperdestabilized a novel unstable green fluorescent protein fusion that contains a destabilization domain of a putative barley 1-aminocyclopropane-1-carboxylate synthase, suggesti ...	2006	17114351
the transcription factors wrky11 and wrky17 act as negative regulators of basal resistance in arabidopsis thaliana.	transcription factors are believed to play a pivotal role in the activation and fine-tuning of plant defense responses, but little is known about the exact function of individual transcription factors in this process. we analyzed the role of the iid subfamily of wrky transcription factors in the regulation of basal resistance to pseudomonas syringae pv tomato (pst). the expression of four members of the subfamily was induced upon challenge with virulent and avirulent strains of pst. mutant analy ...	2006	17114354
a constitutive shade-avoidance mutant implicates tir-nbs-lrr proteins in arabidopsis photomorphogenic development.	in plants, light signals caused by the presence of neighbors accelerate stem growth and flowering and induce a more erect position of the leaves, a developmental strategy known as shade-avoidance syndrome. in addition, mutations in the photoreceptors that mediate shade-avoidance responses enhance disease susceptibility in arabidopsis thaliana. here, we describe the arabidopsis constitutive shade-avoidance1 (csa1) mutant, which shows a shade-avoidance phenotype in the absence of shade and enhance ...	2006	17114357
syringolin a, a new plant elicitor from the phytopathogenic bacterium pseudomonas syringae pv. syringae, inhibits the proliferation of neuroblastoma and ovarian cancer cells and induces apoptosis.	syringolin a is a new plant elicitor produced by the plant pathogen pseudomonas syringae pv. syringae. the goal of this study was to investigate whether syringolin a exhibits anti-proliferative properties in cancer cells. the treatment of human neuroblastoma (nb) cells (sk-n-sh and lan-1) and human ovarian cancer cells (skov3) with syringolin a (0-100 microm) inhibited cell proliferation in a dose-dependent manner. the ic(50) (50% inhibition) for each cell line ranged between 20 microm and 25 mi ...	2006	17109642
induction of a salicylic acid glucosyltransferase, atsgt1, is an early disease response in arabidopsis thaliana.	endogenous salicylic acid (sa) and its predominant conjugates, sa 2-o-beta-d-glucoside (sag) and the glucose ester of sa (sge), increase dramatically during plant defense responses. here i report the isolation and characterization of an arabidopsis thaliana udp-glucose:sa glucosyltransferase1 (atsgt1) gene using a tobacco sgt gene previously reported, whose product catalyzes the formation of both sag and sge. the recombinant atsgt1 protein had significant activities with sa and benzoic acid, and ...	2006	17085977
[molecular cloning and characterization of a novel wrky gene from brassica chinensis].	a new wrky gene was cloned from brassica chinensis by rapid amplification of cdna ends (race). the full-length cdna of bcwrky was 1175 bp long and contained a 924 bp open reading frame (orf) encoding a putative w-box-binding protein of 308 amino acids. the predicted bcwrky protein was found to have a potential bipartite nuclear localization sequence (nls-bp) in its n-terminal region followed by a wrky dna-binding domain. bioinformatic analysis revealed that bcwrky resembled other wrky domain-con ...	2006	17086982
substrate recognition, protein dynamics, and iron-sulfur cluster in pseudomonas aeruginosa adenosine 5'-phosphosulfate reductase.	aps reductase catalyzes the first committed step of reductive sulfate assimilation in pathogenic bacteria, including mycobacterium tuberculosis, and is a promising target for drug development. we report the 2.7 a resolution crystal structure of pseudomonas aeruginosa aps reductase in the thiosulfonate intermediate form of the catalytic cycle and with substrate bound. the structure, high-resolution fourier transform ion cyclotron resonance (ft-icr) mass spectrometry, and quantitative kinetic anal ...	2006	17010373
the algt gene of pseudomonas syringae pv. glycinea and new insights into the transcriptional organization of the algt-muc gene cluster.	the phytopathogenic bacterium pseudomonas syringae pv. glycinea infects soybean plants and causes bacterial blight. in addition to p. syringae, the human pathogen pseudomonas aeruginosa and the soil bacterium azotobacter vinelandii produce the exopolysaccharide alginate, a copolymer of d-mannuronic and l-guluronic acids. alginate production in p. syringae has been associated with increased fitness and virulence in planta. alginate biosynthesis is tightly controlled by proteins encoded by the alg ...	2006	17012388
contribution of ethylene biosynthesis for resistance to blast fungus infection in young rice plants.	the role of ethylene (et) in resistance to infection with blast fungus (magnaporthe grisea) in rice (oryza sativa) is poorly understood. to study it, we quantified et levels after inoculation, using young rice plants at the four-leaf stage of rice cv nipponbare (wild type) and its isogenic plant (il7), which contains the pi-i resistance gene to blast fungus race 003. small necrotic lesions by hypersensitive reaction (hr) were formed at 42 to 72 h postinoculation (hpi) in resistant il7 leaves, an ...	2006	17012402
ndr1 interaction with rin4 mediates the differential activation of multiple disease resistance pathways in arabidopsis.	recognition of pathogens by plants involves the coordinated efforts of molecular chaperones, disease resistance (r) proteins, and components of disease resistance signaling pathways. characterization of events associated with pathogen perception in arabidopsis thaliana has advanced understanding of molecular genetic mechanisms associated with disease resistance and protein interactions critical for the activation of resistance signaling. regulation of r protein-mediated signaling in response to ...	2006	17012600
closing the circle on the discovery of genes encoding hrp regulon members and type iii secretion system effectors in the genomes of three model pseudomonas syringae strains.	pseudomonas syringae strains translocate large and distinct collections of effector proteins into plant cells via the type iii secretion system (t3ss). mutations in t3ss-encoding hrp genes are unable to elicit the hypersensitive response or pathogenesis in nonhost and host plants, respectively. mutations in individual effectors lack strong phenotypes, which has impeded their discovery. p. syringae effectors are designated hop (hrp outer protein) or avr (avirulence) proteins. some hop proteins ar ...	2006	17073298
regulation of the type iii secretion system in phytopathogenic bacteria.	the type iii secretion system (ttss) is a specialized protein secretion machinery used by numerous gram-negative bacterial pathogens of animals and plants to deliver effector proteins directly into the host cells. in plant-pathogenic bacteria, genes encoding the ttss were discovered as hypersensitive response and pathogenicity (hrp) genes, because mutation of these genes typically disrupts the bacterial ability to cause diseases on host plants and to elicit hypersensitive response on nonhost pla ...	2006	17073299
whole-genome expression profiling defines the hrpl regulon of pseudomonas syringae pv. tomato dc3000, allows de novo reconstruction of the hrp cis clement, and identifies novel coregulated genes.	pseudomonas syringae pv. tomato dc3000 is a model pathogen of tomato and arabidopsis that uses a hypersensitive response and pathogenicity (hrp) type iii secretion system (t3ss) to deliver virulence effector proteins into host cells. expression of the hrp system and many effector genes is activated by the hrpl alternative sigma factor. here, an open reading frame-specific whole-genome microarray was constructed for dc3000 and used to comprehensively identify genes that are differentially express ...	2006	17073300
multiple approaches to a complete inventory of pseudomonas syringae pv. tomato dc3000 type iii secretion system effector proteins.	pseudomonas syringae pv. tomato dc3000 is a pathogen of tomato and arabidopsis that translocates virulence effector proteins into host cells via a type iii secretion system (t3ss). many effector-encoding hypersensitive response and pathogenicity (hrp) outer protein (hop) genes have been identified previously in dc3000 using bioinformatic methods based on hrp promoter sequences and characteristic n-terminal amino acid patterns that are associated with t3ss substrates. to approach completion of th ...	2006	17073301
bioinformatics-enabled identification of the hrpl regulon and type iii secretion system effector proteins of pseudomonas syringae pv. phaseolicola 1448a.	the ability of pseudomonas syringae pv. phaseolicola to cause halo blight of bean is dependent on its ability to translocate effector proteins into host cells via the hypersensitive response and pathogenicity (hrp) type iii secretion system (t3ss). to identify genes encoding type iii effectors and other potential virulence factors that are regulated by the hrpl alternative sigma factor, we used a hidden markov model, weight matrix model, and type iii targeting-associated patterns to search the g ...	2006	17073302
salmonella produces an o-antigen capsule regulated by agfd and important for environmental persistence.	in this study, we show that salmonella produces an o-antigen capsule coregulated with the fimbria- and cellulose-associated extracellular matrix. structural analysis of purified salmonella extracellular polysaccharides yielded predominantly a repeating oligosaccharide unit similar to that of salmonella enterica serovar enteritidis lipopolysaccharide o antigen with some modifications. putative carbohydrate transport and regulatory operons important for capsule assembly and translocation, designat ...	2006	17079680
from the academy: colloquium review. unique characteristics of xanthomonas oryzae pv. oryzae avrxa21 and implications for plant innate immunity.	this article provides a brief overview of some of the major concepts and molecular features of plant and animal innate immune systems. the rice pathogen recognition receptor, xa21, confers resistance to xanthomonas oryzae pv. oryzae strains producing the avrxa21 elicitor. xa21 codes for a receptor-like kinase consisting of an extracellular leucine-rich repeat domain, a transmembrane domain, and a cytoplasmic kinase domain. we show that avrxa21 activity requires the presence of rax (required for ...	2006	17082309
transcriptome changes in the phenylpropanoid pathway of glycine max in response to pseudomonas syringae infection.	reports of plant molecular responses to pathogenic infections have pinpointed increases in activity of several genes of the phenylpropanoid pathway leading to the synthesis of lignin and flavonoids. the majority of those findings were derived from single gene studies and more recently from several global gene expression analyses. we undertook a global transcriptional analysis focused on the response of genes of the multiple branches of the phenylpropanoid pathway to infection by the pseudomonas ...	2006	17083738
biofilm formation and cellulose expression among diverse environmental pseudomonas isolates.	the ability to form biofilms is seen as an increasingly important colonization strategy among both pathogenic and environmental bacteria. a survey of 185 plant-associated, phytopathogenic, soil and river pseudomonas isolates resulted in 76% producing biofilms at the air-liquid (a-l) interface after selection in static microcosms. considerable variation in biofilm phenotype was observed, including waxy aggregations, viscous and floccular masses, and physically cohesive biofilms with continuously ...	2006	17014498
the three-dimensional structure of the flagellar rotor from a clockwise-locked mutant of salmonella enterica serovar typhimurium.	three-dimensional reconstructions from electron cryomicrographs of the rotor of the flagellar motor reveal that the symmetry of individual m rings varies from 24-fold to 26-fold while that of the c rings, containing the two motor/switch proteins flim and flin, varies from 32-fold to 36-fold, with no apparent correlation between the symmetries of the two rings. results from other studies provided evidence that, in addition to the transmembrane protein flif, at least some part of the third motor/s ...	2006	17015643
survival and growth in the presence of elevated copper: transcriptional profiling of copper-stressed pseudomonas aeruginosa.	transcriptional profiles of pseudomonas aeruginosa exposed to two separate copper stress conditions were determined. actively growing bacteria subjected to a pulse of elevated copper for a short period of time was defined as a "copper-shocked" culture. conversely, copper-adapted populations were defined as cells actively growing in the presence of elevated copper. expression of 405 genes changed in the copper-shocked culture, compared to 331 genes for the copper-adapted cultures. not surprisingl ...	2006	17015663
the genome sequence of mannheimia haemolytica a1: insights into virulence, natural competence, and pasteurellaceae phylogeny.	the draft genome sequence of mannheimia haemolytica a1, the causative agent of bovine respiratory disease complex (brdc), is presented. strain atcc baa-410, isolated from the lung of a calf with brdc, was the dna source. the annotated genome includes 2,839 coding sequences, 1,966 of which were assigned a function and 436 of which are unique to m. haemolytica. through genome annotation many features of interest were identified, including bacteriophages and genes related to virulence, natural comp ...	2006	17015664
the aaur-aaus two-component system regulates uptake and metabolism of acidic amino acids in pseudomonas putida.	pseudomonas putida kt2440 metabolizes a wide range of carbon and nitrogen sources, including many amino acids. in this study, a sigma54-dependent two-component system that controls the uptake and metabolism of acidic amino acids was identified. the system (designated aau, for acidic amino acid utilization) involves a sensor histidine kinase, aaus, encoded by pp1067, and a response regulator, aaur, encoded by pp1066. aaur and aaus deletion mutants were unable to efficiently utilize aspartate (asp ...	2006	17021207
occurrence of sep insecticidal toxin complex genes in serratia spp. and yersinia frederiksenii.	some strains of serratia entomophila and s. proteamaculans cause amber disease of the grass grub costelytra zealandica (coleoptera: scarabaeidae). three genes required for virulence, sepabc, are located on a large plasmid, padap. sequence analysis suggests that the sepabc gene cluster may be part of a horizontally mobile region. this study presents evidence for the putative mobility of the sep genes of padap. southern blot analysis showed that orthologues of the sep genes reside on plasmids with ...	2006	17021209
yeast increases resistance in arabidopsis against pseudomonas syringae and botrytis cinerea by salicylic acid-dependent as well as -independent mechanisms.	cell-wall and glucopeptide components of yeast have been reported to exhibit elicitor activity. the mode of action of defense activation by yeast is not known so far. in this study, we used the model plant arabidopsis to investigate the activation of defense responses by yeast, the effect on resistance against different pathogens, and the mode of action. treatment of arabidopsis plants with an autoclaved yeast suspension induced the expression of systemic acquired resistance-related genes and ac ...	2006	17022178
the pti1-like kinase zmpti1a from maize (zea mays l.) co-localizes with callose at the plasma membrane of pollen and facilitates a competitive advantage to the male gametophyte.	the tomato kinase pto confers resistance to bacterial speck disease caused by pseudomonas syringae pv. tomato in a gene for gene manner. upon recognition of specific avirulence factors the pto kinase activates multiple signal transduction pathways culminating in induction of pathogen defense. the soluble cytoplasmic serine/threonine kinase pti1 is one target of pto phosphorylation and is involved in the hypersensitive response (hr) reaction. however, a clear role of pti1 in plant pathogen resist ...	2006	17022830
modifications to the arabidopsis defense proteome occur prior to significant transcriptional change in response to inoculation with pseudomonas syringae.	alterations in the proteome of arabidopsis (arabidopsis thaliana) leaves during responses to challenge by pseudomonas syringae pv tomato dc3000 were analyzed using two-dimensional gel electrophoresis. protein changes characteristic of the establishment of disease, basal resistance, and resistance-gene-mediated resistance were examined by comparing responses to dc3000, a hrp mutant, and dc3000 expressing avrrpm1, respectively. the abundance of each protein identified was compared with that of sel ...	2006	17028151
the tomato nbarc-lrr protein prf interacts with pto kinase in vivo to regulate specific plant immunity.	immunity in tomato (solanum lycopersicum) to pseudomonas syringae bacteria expressing the effector proteins avrpto and avrptob requires both pto kinase and the nbarc-lrr (for nucleotide binding domain shared by apaf-1, certain r gene products, and ced-4 fused to c-terminal leucine-rich repeats) protein prf. pto plays a direct role in effector recognition within the host cytoplasm, but the role of prf is unknown. we show that pto and prf are coincident in the signal transduction pathway that cont ...	2006	17028203
a homologue of the 3-oxoacyl-(acyl carrier protein) synthase iii gene located in the glycosylation island of pseudomonas syringae pv. tabaci regulates virulence factors via n-acyl homoserine lactone and fatty acid synthesis.	pseudomonas syringae pv. tabaci 6605 possesses a genetic region involved in flagellin glycosylation. this region is composed of three open reading frames: orf1, orf2, and orf3. our previous study revealed that orf1 and orf2 encode glycosyltransferases; on the other hand, orf3 has no role in posttranslational modification of flagellin. although the function of orf3 remained unclear, an orf3 deletion mutant (deltaorf3 mutant) had reduced virulence on tobacco plants. orf3 shows significant homology ...	2006	17028280
pr genes of apple: identification and expression in response to elicitors and inoculation with erwinia amylovora.	in the past decade, much work has been done to dissect the molecular basis of the defence signalling pathway in plants known as systemic acquired resistance (sar). most of the work has been carried out in model species such as arabidopsis, with little attention paid to woody plants. however within the range of species examined, components of the pathway seem to be highly conserved. in this study, we attempted to identify downstream components of the sar pathway in apple to serve as markers for i ...	2006	17029637
early responsive to dehydration 15, a negative regulator of abscisic acid responses in arabidopsis.	early responsive to dehydration 15 (erd15) is rapidly induced in response to various abiotic and biotic stress stimuli in arabidopsis (arabidopsis thaliana). modulation of erd15 levels by overexpression or rnai silencing altered the responsiveness of the transgenic plants to the phytohormone abscisic acid (aba). overexpression of erd15 reduced the aba sensitivity of arabidopsis manifested in decreased drought tolerance and in impaired ability of the plants to increase their freezing tolerance in ...	2006	17056758
arabidopsis wrky33 transcription factor is required for resistance to necrotrophic fungal pathogens.	plant wrky transcription factors are key regulatory components of plant responses to microbial infection. in addition to regulating the expression of defense-related genes, wrky transcription factors have also been shown to regulate cross-talk between jasmonate- and salicylate-regulated disease response pathways. the two pathways mediate resistance against different types of microbial pathogens, and there are numerous reports of antagonistic interactions between them. here we show that mutations ...	2006	17059405
the arabidopsis map kinase kinase mkk1 participates in defence responses to the bacterial elicitor flagellin.	plants sense pathogens through both pathogen-associated molecular patterns and recognition of race-specific virulence factors, which induce basal defence or an accelerated defence (often manifest in the form of local cell death), respectively. a mitogen-activated protein kinase (mapk) module in arabidopsis was previously proposed to signal from perception of the bacterial elicitor flagellin to the activation of basal defence-related genes. here, we present evidence for a parallel mapk-signalling ...	2006	17059410
evolution of the yellow/major royal jelly protein family and the emergence of social behavior in honey bees.	the genomic architecture underlying the evolution of insect social behavior is largely a mystery. eusociality, defined by overlapping generations, parental brood care, and reproductive division of labor, has most commonly evolved in the hymenopteran insects, including the honey bee apis mellifera. in this species, the major royal jelly protein (mrjp) family is required for all major aspects of eusocial behavior. here, using data obtained from the a. mellifera genome sequencing project, we demons ...	2006	17065613
using the nucleotide substitution rate matrix to detect horizontal gene transfer.	horizontal gene transfer (hgt) has allowed bacteria to evolve many new capabilities. because transferred genes perform many medically important functions, such as conferring antibiotic resistance, improved detection of horizontally transferred genes from sequence data would be an important advance. existing sequence-based methods for detecting hgt focus on changes in nucleotide composition or on differences between gene and genome phylogenies; these methods have high error rates.	2006	17067382
flagellin suppresses epithelial apoptosis and limits disease during enteric infection.	flagellin, the primary component of bacterial flagella, is a potent activator of toll-like receptor 5 (tlr5) signaling and is a major proinflammatory determinant of enteropathogenic salmonella. in accordance with this, we report here that aflagellate salmonella mutants are impaired in their ability to up-regulate proinflammatory and anti-apoptotic effector molecules in murine models of salmonellosis and that these mutants elicit markedly reduced early mucosal inflammation relative to their isoge ...	2006	17071592
a pathogen-inducible endogenous sirna in plant immunity.	rna interference, mediated by small interfering rnas (sirnas), is a conserved regulatory process that has evolved as an antiviral defense mechanism in plants and animals. it is not known whether host cells also use sirnas as an antibacterial defense mechanism in eukaryotes. here, we report the discovery of an endogenous sirna, nat-sirnaatgb2, that is specifically induced by the bacterial pathogen pseudomonas syringae carrying effector avrrpt2. we demonstrate that the biogenesis of this sirna req ...	2006	17071740
[phenotypical and genotypical characteristics of the pathogen in lupine bacterial brown spottiness].	it has been determined with the help of analyzing the complex of phenotypical and genotypical properties, that pseudomonas lupini is not a separate species. it has been shown that lupin's bacterial spot is induced by phytopathogenic bacteria of two species p. syringae and p. savastanoi. on the basis of their high phenotypical and genotypical similarity with a typical strain pseudomonas syringae pv. syringae b1027 the majority of investigated strains are related to p. syringae. the only exception ...	2006	17243363
natural variation in partial resistance to pseudomonas syringae is controlled by two major qtls in arabidopsis thaliana.	low-level, partial resistance is pre-eminent in natural populations, however, the mechanisms underlying this form of resistance are still poorly understood.	2006	17205127
high precision multi-genome scale reannotation of enzyme function by eficaz.	the functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. we have performed a reannotation of 245 genomes using an updated version of eficaz, a highly precise method for enzyme function prediction.	2006	17166279
a mutation in an exbd gene reduces tagetitoxin production by pseudomonas syringae pv. tagetis.	a mutant of pseudomonas syringae pv. tagetis eb037 with limited ability to produce tagetitoxin was isolated after transposon mutagenesis and the mutation was characterized. the mutation occurred in a gene with a high degree of sequence identity to exbd. exbd is contiguous with tonb and exbb upstream and with a gene for a tonb-dependent receptor downstream. using reverse transcription - polymerase chain reaction with rna from the wild-type and exbd mutant strains, we demonstrated that the mutatio ...	2006	17215893
detection and sequence analysis of an altered pectate lyase gene in pseudomonas syringae pv. glycinea and related bacteria.	pectate lyase (pl) is a potent cell wall-degrading enzyme known to play a role in the microbial infection of plants. we re-examined the pectolytic property of seven representative pathovars of pseudomonas syringae. none of the 10 p. syringae pv. glycinea strains examined exhibited pectolytic activity. however, the pl gene (pel) was detected by southern hybridization in four out of four p. syringae pv. glycinea strains examined. a p. syringae pv. glycinea pel gene was cloned, sequenced, and predi ...	2006	17215896
[agriculture microbiology and microbe interaction with plants].	about the characterization and distribution of novel nitrogen-fixing burkholderia species associated with maize and other plants and their potential use on the plant growth was presented in this symposium. the symposium included studies directed to the revegetation of eroded areas by using plant growth promoting rhizo-bacteria and mycorrizal fungi associated with desert plants, as well as studies related with the resistance of arbuscular mycorrhizal fungi to heavy metals associated with the envi ...	2006	17578087
promoter activation of pepper class ii basic chitinase gene, cachi2, and enhanced bacterial disease resistance and osmotic stress tolerance in the cachi2-overexpressing arabidopsis.	the activation of the cachi2 promoter as the result of bacterial infection and osmotic stresses was examined using the agrobacterium-mediated transient expression assay. several stress-related cis-acting elements were revealed within the upstream genomic sequence of the cachi2 gene. in tobacco leaf tissues transiently transformed with the cachi2 promoter-beta-glucuronidase (gus) gene, the cachi2 promoter was up-regulated by pseudomonas syringae pv. tabaci infection. the cachi2-gus activation was ...	2006	16151843
comparative characterization and expression analysis of the four old yellow enzyme homologues from shewanella oneidensis indicate differences in physiological function.	shewanella oneidensis contains four genes that encode proteins that have high sequence identity with yeast oye (old yellow enzyme, an nadph oxidoreductase), the well-studied archetype of the oye protein family. the present paper describes the first comparative study of oyes that are present in a single bacterial species, performed to gain insight into their biochemical properties and physiological importance. the four proteins [named sye1-sye4 (shewanella yellow enzyme 1-4)] were expressed as gl ...	2006	16293111
pleiotropic costs of niche expansion in the rna bacteriophage phi 6.	natural and experimental systems have failed to universally demonstrate a trade-off between generalism and specialism. when a trade-off does occur it is difficult to attribute its cause to antagonistic pleiotropy without dissecting the genetic basis of adaptation, and few previous experiments provide these genetic data. here we investigate the evolution of expanded host range (generalism) in the rna virus phi6, an experimental model system allowing adaptive mutations to be readily identified. we ...	2006	16299384
genetic and molecular characterization of the i locus of phaseolus vulgaris.	the i locus of the common bean, phaseolus vulgaris, controls the development of four different phenotypes in response to inoculation with bean common mosaic virus, bean common mosaic necrosis virus, several other related potyviruses, and one comovirus. we have generated a high-resolution linkage map around this locus and have aligned it with a physical map constructed with bac clones. these clones were obtained from a library of the cultivar "sprite," which carries the dominant allele at the i l ...	2006	16322513
accumulation of gentisic acid as associated with systemic infections but not with the hypersensitive response in plant-pathogen interactions.	in the present work we have studied the accumulation of gentisic acid (2,5-dihydroxybenzoic acid, a metabolic derivative of salicylic acid, sa) in the plant-pathogen systems, cucumis sativus and gynura aurantiaca, infected with either prunus necrotic ringspot virus (pnrsv) or the exocortis viroid (cevd), respectively. both pathogens produced systemic infections and accumulated large amounts of the intermediary signal molecule gentisic acid as ascertained by electrospray ionization mass spectrome ...	2006	16331468
different versions of pseudomonas syringae pv. tomato dc3000 exist due to the activity of an effector transposon.	summary the plant pathogenic bacterium pseudomonas syringae pv. tomato strain dc3000 is a key model organism to study plant-pathogen interactions. we realized that two versions of this strain, which carry plasmids of different sizes, exist in our strain collections. the difference was located to a 9.4-kb deletion within the larger of the two endogenous plasmids encompassing the partitioning genes para and parb and a putative mobile element encoding the type iii effector hopam1-2 (formerly avrppi ...	2006	20507452
extensin over-expression in arabidopsis limits pathogen invasiveness.	summary the function of the cell wall protein extensin has been the subject of much speculation since it was first isolated over 40 years ago. in order to investigate the role of extensins in plant defence, we used the gain-of-function strategy to generate transgenic arabidopsis plants over-expressing the ext1 extensin gene. these were infected with the virulent bacterial pathogen pseudomonas syringae dc3000 and symptom development was monitored. lesions on the transgenics were on average five-f ...	2006	20507471
a novel link between tomato gras genes, plant disease resistance and mechanical stress response.	summary members of the gras family of transcriptional regulators have been implicated in the control of plant growth and development, and in the interaction of plants with symbiotic bacteria. here we examine the complexity of the gras gene family in tomato (solanum lycopersicum) and investigate its role in disease resistance and mechanical stress. a large number of tomato ests corresponding to gras transcripts were retrieved from the public database and assembled in 17 contigs of putative genes. ...	2006	20507472
the internal glycine-rich motif and cysteine suppress several effects of the hpag(xooc) protein in plants.	abstract hpag(xooc), produced by xanthomonas oryzae pv. oryzicola, is a member of harpin group of proteins that stimulate plant growth, hypersensitive cell death (hcd), and pathogen defense. the protein contains two copies of the glycine-rich motif (grm), a characteristic of harpins, and a cysteine, which is absent in other harpins. genetic modification generated the pro-tein mutants hpag(xooc)mg (mg) by deleting grms and hpag(xooc)c47t (c47t) by replacing cysteine with threonine. when applied t ...	2006	18943492
influence of ring nematode infestation and calcium, nitrogen, and indoleacetic acid applications on peach susceptibility to pseudomonas syringae pv. syringae.	abstract two field experiments were conducted to study the effects of added nitrogen, calcium, and indoleacetic acid, in the presence or absence of ring nematodes (mesocriconema xenoplax), on susceptibility of peach to bacterial canker. when noninfested soil was inoculated with ring nematodes, peach tree susceptibility to bacterial canker infection caused by pseudomonas syringae pv. syringae was dramatically increased after a period of 2 years. however, no evidence was found that ring nematode i ...	2006	18943178
effects of inducers of systemic acquired resistance on reproduction of meloidogyne javanica and rotylenchulus reniformis in pineapple.	the potency of the inducers of systemic acquired resistance (sar), acibenzolar-s-methyl, dl-alpha-amino-n-butyric acid (aaba), dl-beta-amino-n-butyric acid (baba), gamma-amino-n-butyric acid (gaba), p-aminobenzoic acid (paba), riboflavin, and salicylic acid (sa), in reducing reproduction of meloidogyne javanica and rotylenchulus reniformis in pineapple was investigated. all inducers were applied as foliar sprays to 1-mon-old pineapple plants (20 ml/plant) grown in 22-cm-diam. pots in the greenho ...	2006	19259535
interaction between nitrogen-fertilized peach trees and expression of syrb, a gene involved in syringomycin production in pseudomonas syringae pv. syringae.	abstract the in vitro expression of the syrb gene that controls the synthesis of syringomycin, a non-host-specific phytotoxin produced by pseudomonas syringae pv. syringae van hall, was studied using aqueous extracts derived from bark tissues collected from nitrogen-fertilized and nonfertilized peach trees. expression of the syrb gene was quantified as beta- galactosidase activity expressed by p. syringae pv. syringae b3ar-132 containing a syrb::lacz fusion. gene expression was significantly les ...	2005	18943325
pseudomonas syringae pv. coryli, the causal agent of bacterial twig dieback of corylus avellana.	abstract thirty-eight bacterial strains isolated from hazelnut (corylus avellana) cv. tonda gentile delle langhe showing a twig dieback in piedmont and sardinia, italy, were studied by a polyphasic approach. all strains were assessed by fatty acids analysis and repetitive sequence-based polymerase chain reaction (pcr) fingerprinting using box and eric primer sets. representative strains also were assessed by sequencing the 16s rdna and hrpl genes, determining the presence of the syrb gene, testi ...	2005	18943363
involvement of jasmonic acid/ethylene signaling pathway in the systemic resistance induced in cucumber by trichoderma asperellum t203.	abstract trichoderma spp. are effective biocontrol agents for a number of soilborne plant pathogens, and some are also known for their ability to enhance plant growth. it was recently suggested that trichoderma also affects induced systemic resistance (isr) mechanism in plants. analysis of signal molecules involved in defense mechanisms and application of specific inhibitors indicated the involvement of jasmonic acid and ethylene in the protective effect conferred by trichoderma spp. against the ...	2005	18943839
a constitutive pr-1::luciferase expression screen identifies arabidopsis mutants with differential disease resistance to both biotrophic and necrotrophic pathogens.	summary a complex signal transduction network involving salicylic acid, jasmonic acid and ethylene underlies disease resistance in arabidopsis. to understand this defence signalling network further, we identified mutants that expressed the marker gene pr-1::luciferase in the absence of pathogen infection. these cir mutants all display constitutive expression of a suite of defence-related genes but exhibit different disease resistance profiles to two biotrophic pathogens, pseudomonas syringae pv. ...	2005	20565636
lineage-specific regions in pseudomonas syringae pv tomato dc3000.	summary comparative analyses of the chromosome of pseudomonas syringae pv tomato dc3000 with the finished, complete genomes of pseudomonas aeruginosa pao1, an animal pathogen, and the non-pathogenic soil inhabitant pseudomonas putida kt2440 revealed a high degree of sequence conservation in genes involved in 'housekeeping functions'. however, divergence is present among these three fluorescent pseudomonads, yielding 'suites' of species-specific genes that may provide the genetic basis for adapta ...	2005	20565638
coronatine and salicylic acid: the battle between arabidopsis and pseudomonas for phytohormone control.	summary the phytotoxin coronatine is a jasmonate mimic produced by pseudomonas syringae pv. tomato (pst). coronatine acts as a virulence factor in arabidopsis and mutants insensitive to coronatine are resistant to pst and have higher levels of salicylic acid (sa). in this work we used the sa-deficient lines nahg and sid2-2 to determine if coronatine acts directly as a virulence factor or indirectly by sa suppression. using coronatine-deficient pst mutants we demonstrated that the lack of coronat ...	2005	20565640
cdna-aflp reveals genes differentially expressed during the hypersensitive response of cassava.	summary the tropical staple cassava is subject to several major diseases, such as cassava bacterial blight, caused by xanthomonas axonopodis pv. manihotis. disease-resistant genotypes afford the only practical solution, yet despite the global importance of this crop, little is known about its defence mechanisms. cdna-aflp was used to isolate cassava genes differentially expressed during the hypersensitive reaction (hr) of leaves in response to an incompatible pseudomonas syringae pathovar. seven ...	2005	20565643
the hrp pathogenicity island of erwinia amylovora and identification of three novel genes required for systemic infectiondouble dagger.	summary sequence analysis of the region bordering the hrp/dsp gene cluster of erwinia amylovora strain ea321, which causes fire blight, revealed characteristics of pathogenicity islands (pais). included are genes for a phage integrase, a trna(phe), several orthologues of genes of yapi, a pai of yersinia pseudotuberculosis, and several putative virulence genes with hrpl-dependent promoter motifs. the island is designated the hrp pai of e. amylovora. it is comprised of a chromosomal region of c. 6 ...	2005	20565644
determinants of pseudomonas putida wcs358 involved in inducing systemic resistance in plants.	summary pseudomonas putida wcs358 is a plant growth-promoting rhizobacterium originally isolated from the rhizosphere of potato. it can suppress soil-borne plant diseases by siderophore-mediated competition for iron, but it has also been reported to result in induced systemic resistance (isr) in arabidopsis thaliana. bacterial determinants of this strain involved in inducing systemic resistance in arabidopsis were investigated using a tn5 transposon mutant defective in biosynthesis of the fluore ...	2005	20565648
the pseudomonas syringae phytotoxin coronatine promotes virulence by overcoming salicylic acid-dependent defences in arabidopsis thaliana.	summary successful pathogen infection likely involves the suppression of general antimicrobial host defences. one pseudomonas syringae virulence factor proposed to act in this manner is coronatine (cor), a phytotoxin believed to function as an analogue of one or more jasmonates, a family of plant growth regulators. cor biosynthetic (cor(-)) mutants of p. syringae pv. tomato strain dc3000 exhibit reduced virulence on arabidopsis thaliana and tomato. in the present study, three genetically and bio ...	2005	20565685
characterization of a unique chromosomal copper resistance gene cluster from xanthomonas campestris pv. vesicatoria.	we characterized the copper resistance genes in strain xvp26 of xanthomonas campestris pv. vesicatoria, which was originally isolated from a pepper plant in taiwan. the copper resistance genes were localized to a 7,652-bp region which, based on pulsed-field gel electrophoresis and southern hybridization, was determined to be located on the chromosome. these genes hybridized only weakly, as determined by southern analysis, to other copper resistance genes in xanthomonas and pseudomonas strains. w ...	2005	16332814
bleeding sap and old wood are the two main sources of contamination of merging organs of vine plants by xylophilus ampelinus, the causal agent of bacterial necrosis.	the spatial distribution of vine plants contaminated by xylophilus ampelinus, the agent responsible for bacterial necrosis, was studied over a 5-year period within two vineyards in the cognac area. both vineyards were planted with vitis vinifera cv. ugni blanc but were different in age and agronomic location. the emission of x. ampelinus in contaminated bleeding sap was observed during vine sprouting. contaminated bleeding sap is an important source of inoculum for external contamination due to ...	2005	16332815
multilocus sequence type system for the plant pathogen xylella fastidiosa and relative contributions of recombination and point mutation to clonal diversity.	multilocus sequence typing (mlst) identifies and groups bacterial strains based on dna sequence data from (typically) seven housekeeping genes. mlst has also been employed to estimate the relative contributions of recombination and point mutation to clonal divergence. we applied mlst to the plant pathogen xylella fastidiosa using an initial set of sequences for 10 loci (9.3 kb) of 25 strains from five different host plants, grapevine (pd strains), oleander (ols strains), oak (oak strains), almon ...	2005	16332839
two novel bacterial biosensors for detection of nitrate availability in the rhizosphere.	the nitrate-regulated promoter of narg in escherichia coli was fused to promoterless ice nucleation (inaz) and green fluorescent protein (gfp) reporter genes to yield the nitrate-responsive gene fusions in plasmids pnice and pngfp, respectively. while the promoter of narg is normally nitrate responsive only under anaerobic conditions, the l28h-fnr gene was provided in trans to enable nitrate-dependent expression of these reporter gene fusions even under aerobic conditions in both e. coli dh5alph ...	2005	16332845
engineering pseudomonas fluorescens for biodegradation of 2,4-dinitrotoluene.	using the genes encoding the 2,4-dinitrotoluene degradation pathway enzymes, the nonpathogenic psychrotolerant rhizobacterium pseudomonas fluorescens atcc 17400 was genetically modified for degradation of this priority pollutant. first, a recombinant strain designated mp was constructed by conjugative transfer from burkholderia sp. strain dnt of the pjs1 megaplasmid, which contains the dnt genes for 2,4-dinitrotoluene degradation. this strain was able to grow on 2,4-dinitrotoluene as the sole so ...	2005	16332883
a novel endogenous inhibitor of the secreted streptococcal nad-glycohydrolase.	the streptococcus pyogenes nad-glycohydrolase (spn) is a toxic enzyme that is introduced into infected host cells by the cytolysin-mediated translocation pathway. however, how s. pyogenes protects itself from the self-toxicity of spn had been unknown. in this report, we describe immunity factor for spn (ifs), a novel endogenous inhibitor that is essential for spn expression. a small protein of 161 amino acids, ifs is localized in the bacterial cytoplasmic compartment. ifs forms a stable complex ...	2005	16333395
comparative analysis of programmed cell death pathways in filamentous fungi.	fungi can undergo autophagic- or apoptotic-type programmed cell death (pcd) on exposure to antifungal agents, developmental signals, and stress factors. filamentous fungi can also exhibit a form of cell death called heterokaryon incompatibility (hi) triggered by fusion between two genetically incompatible individuals. with the availability of recently sequenced genomes of aspergillus fumigatus and several related species, we were able to define putative components of fungi-specific death pathway ...	2005	16336669
activation of defense responses in chinese cabbage by a nonhost pathogen, pseudomonas syringae pv. tomato.	pseudomonas syringae pv. tomato (pst) causes a bacterial speck disease in tomato and arabidopsis. in chinese cabbage, in which host-pathogen interactions are not well understood, pst does not cause disease but rather elicits a hypersensitive response. pst induces localized cell death and h2o2 accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. pre-inoculation with pst was found to induce resistance to erwinia carotovora subsp. carotovora, a pathogen that causes soft r ...	2005	16336791
alternative sigma factors and their roles in bacterial virulence.	sigma factors provide promoter recognition specificity to rna polymerase holoenzyme, contribute to dna strand separation, and then dissociate from the core enzyme following transcription initiation. as the regulon of a single sigma factor can be composed of hundreds of genes, sigma factors can provide effective mechanisms for simultaneously regulating expression of large numbers of prokaryotic genes. one newly emerging field is identification of the specific roles of alternative sigma factors in ...	2005	16339734
novel cyclic lipodepsipeptide from pseudomonas syringae pv. lachrymans strain 508 and syringopeptin antimicrobial activities.	the syringopeptins are a group of antimicrobial cyclic lipodepsipeptides produced by several plant-associated pseudomonads. a novel syringopeptin, sp508, was shown to be produced as two homologs (a and b) by pseudomonas syringae pv. lachrymans strain 508 from apple and to structurally resemble syringopeptin sp22. sp508 differed from sp22 and other syringopeptins by having three instead of four alpha,beta-unsaturated amino acids and a longer beta-hydroxy acyl chain. both sp508 and sp22 displayed ...	2005	16304170
pathogen-responsive expression of glycosyltransferase genes ugt73b3 and ugt73b5 is necessary for resistance to pseudomonas syringae pv tomato in arabidopsis.	the genome sequencing of arabidopsis (arabidopsis thaliana) has revealed that secondary metabolism plant glycosyltransferases (ugts) are encoded by an unexpectedly large multigenic family of 120 members. very little is known about their actual function in planta, in particular during plant pathogen interactions. among them, members of the group d are of particular interest since they are related to ugts involved in stress-inducible responses in other plant species. we provide here a detailed ana ...	2005	16306146
four-helix bundle: a ubiquitous sensory module in prokaryotic signal transduction.	motivation: transmembrane chemoreceptors in escherichia coli utilize ligand-binding domains for detecting various external signals. the structure of this domain in the e.coli aspartate receptor, tar, is known and its signal transduction mechanism is under investigation. current domain models for this important sensory module are inaccurate and, therefore, cannot reveal the distribution of this domain within the current genomic landscape. results: we carried out sensitive and exhaustive psi-blast ...	2005	16306392
role of the pseudomonas fluorescens alginate lyase (algl) in clearing the periplasm of alginates not exported to the extracellular environment.	alginate is an industrially widely used polysaccharide produced by brown seaweeds and as an exopolysaccharide by bacteria belonging to the genera pseudomonas and azotobacter. the polymer is composed of the two sugar monomers mannuronic acid and guluronic acid (g), and in all these bacteria the genes encoding 12 of the proteins essential for synthesis of the polymer are clustered in the genome. interestingly, 1 of the 12 proteins is an alginate lyase (algl), which is able to degrade the polymer d ...	2005	16321942
identification of a twin-arginine translocation system in pseudomonas syringae pv. tomato dc3000 and its contribution to pathogenicity and fitness.	the bacterial plant pathogen pseudomonas syringae pv. tomato dc3000 (dc3000) causes disease in arabidopsis thaliana and tomato plants, and it elicits the hypersensitive response in nonhost plants such as nicotiana tabacum and nicotiana benthamiana. while these events chiefly depend upon the type iii protein secretion system and the effector proteins that this system translocates into plant cells, additional factors have been shown to contribute to dc3000 virulence and still many others are likel ...	2005	16321949
genetic requirements for potassium ion-dependent colony spreading in bacillus subtilis.	undomesticated strains of bacillus subtilis exhibit extensive colony spreading on certain soft agarose media: first the formation of dendritic clusters of cells, followed by spreading (pellicle-like) growth to cover the entire surface. these phases of colonization are dependent on the level of potassium ion (k(+)) but independent of flagella, as verified with a mutant with a hag gene replacement; this latter finding highlights the importance of sliding motility in colony spreading. exploring the ...	2005	16321950
genetic characterization of pseudomonas fluorescens sbw25 rsp gene expression in the phytosphere and in vitro.	the plant-colonizing pseudomonas fluorescens strain sbw25 harbors a gene cluster (rsp) whose products show similarity to type iii protein secretion systems found in plant and animal pathogens. here we report a detailed analysis of the expression and regulation of the p. fluorescens rsp pathway, both in the phytosphere and in vitro. a combination of chromosomally integrated transcriptional reporter fusions, overexpressed regulatory genes, and specific mutants reveal that promoters controlling exp ...	2005	16321952
a pathogen-inducible patatin-like lipid acyl hydrolase facilitates fungal and bacterial host colonization in arabidopsis.	genes and proteins related to patatin, the major storage protein of potato tubers, have been identified in many plant species and shown to be induced by a variety of environmental stresses. the arabidopsis patatin-like gene family (plps) comprises nine members, two of which (plp2 and plp7) are strongly induced in leaves challenged with fungal and bacterial pathogens. here we show that accumulation of plp2 protein in response to botrytis cinerea or pseudomonas syringae pv. tomato (avrrpt2) is dep ...	2005	16297072
the diphenylether herbicide lactofen induces cell death and expression of defense-related genes in soybean.	lactofen belongs to the diphenylether class of herbicides, which targets protoporphyrinogen oxidase, which in turn causes singlet oxygen generation. in tolerant plants like soybean (glycine max), the chemical nonetheless causes necrotic patches called "bronzing" in contact areas. here it is shown that such bronzing is accompanied by cell death, which was quantified from digital microscopic images using assess software. cellular autofluorescence accompanied cell death, and a homolog of the cell d ...	2005	16299178
haemophilus ducreyi targets src family protein tyrosine kinases to inhibit phagocytic signaling.	haemophilus ducreyi, the etiologic agent of the sexually transmitted disease chancroid, has been shown to inhibit phagocytosis of both itself and secondary targets in vitro. immunodepletion of lspa proteins from h. ducreyi culture supernatant fluid abolished this inhibitory effect, indicating that the lspa proteins are necessary for the inhibition of phagocytosis by h. ducreyi. fluorescence microscopy revealed that macrophages incubated with wild-type h. ducreyi, but not with a lspa1 lspa2 mutan ...	2005	16299270
roles of specific amino acids in the n terminus of pseudomonas aeruginosa flagellin and of flagellin glycosylation in the innate immune response.	the toll-like receptor 5 (tlr5) binding site has been predicted to be in the n terminus of the flagellin molecule. in order to better define the interaction between the n-terminal amino acids of pseudomonas aeruginosa flagellin and tlr5, site-specific mutations were generated between residues 88 and 97 of p. aeruginosa pak flagellin as well as outside of this region. the mutant flagellins were expressed in escherichia coli bl21(plyss), purified by affinity chromatography, and passed through a po ...	2005	16299320
characterization of two non-locus of enterocyte effacement-encoded type iii-translocated effectors, nlec and nled, in attaching and effacing pathogens.	intestinal colonization by enteropathogenic and enterohemorrhagic escherichia coli requires the locus of enterocyte effacement-encoded type iii secretion system. we report that nlec and nled are translocated into host cells via this system. deletion mutants induced attaching and effacing lesions in vitro, while infection of calves or lambs showed that neither gene was required for colonization.	2005	16299341
repetitive extragenic palindromic sequences in the pseudomonas syringae pv. tomato dc3000 genome: extragenic signals for genome reannotation.	repetitive extragenic palindromic (reps) sequences were first described in enterobacteriacea and later in pseudomonas putida. we have detected a new variant (51 base pairs) of rep sequences that appears to be disseminated in more than 300 copies in the pseudomonas syringae dc3000 genome. the finding of rep sequences in p. syringae confirms the broad presence of this type of repetitive sequence in bacteria. we analyzed the distribution of rep sequences and the structure of the clusters, and we sh ...	2005	15808947