| a new autocatalytic activation mechanism for cysteine proteases revealed by prevotella intermedia interpain a. | prevotella intermedia is a major periodontopathogen contributing to human gingivitis and periodontitis. such pathogens release proteases as virulence factors that cause deterrence of host defenses and tissue destruction. a new cysteine protease from the cysteine-histidine-dyad class, interpain a, was studied in its zymogenic and self-processed mature forms. the latter consists of a bivalved moiety made up by two subdomains. in the structure of a catalytic cysteine-to-alanine zymogen variant, the ... | 2008 | 17993455 |
| a new autocatalytic activation mechanism for cysteine proteases revealed by prevotella intermedia interpain a. | prevotella intermedia is a major periodontopathogen contributing to human gingivitis and periodontitis. such pathogens release proteases as virulence factors that cause deterrence of host defenses and tissue destruction. a new cysteine protease from the cysteine-histidine-dyad class, interpain a, was studied in its zymogenic and self-processed mature forms. the latter consists of a bivalved moiety made up by two subdomains. in the structure of a catalytic cysteine-to-alanine zymogen variant, the ... | 2008 | 17993455 |
| global genomic analysis of pseudomonas savastanoi pv. savastanoi plasmids. | pseudomonas savastanoi pv. savastanoi strains harbor native plasmids belonging to the ppt23a plasmid family (pfps) which are detected in all pathovars of the related species pseudomonas syringae examined and contribute to the ecological and pathogenic fitness of their host. however, there is a general lack of information about the gene content of p. savastanoi pv. savastanoi plasmids and their role in the interaction of this pathogen with olive plants. we designed a dna macroarray containing 135 ... | 2008 | 17993520 |
| global genomic analysis of pseudomonas savastanoi pv. savastanoi plasmids. | pseudomonas savastanoi pv. savastanoi strains harbor native plasmids belonging to the ppt23a plasmid family (pfps) which are detected in all pathovars of the related species pseudomonas syringae examined and contribute to the ecological and pathogenic fitness of their host. however, there is a general lack of information about the gene content of p. savastanoi pv. savastanoi plasmids and their role in the interaction of this pathogen with olive plants. we designed a dna macroarray containing 135 ... | 2008 | 17993520 |
| massetolide a biosynthesis in pseudomonas fluorescens. | massetolide a is a cyclic lipopeptide (clp) antibiotic produced by various pseudomonas strains from diverse environments. cloning, sequencing, site-directed mutagenesis, and complementation showed that massetolide a biosynthesis in p. fluorescens ss101 is governed by three nonribosomal peptide synthetase (nrps) genes, designated massa, massb, and massc, spanning approximately 30 kb. prediction of the nature and configuration of the amino acids by in silico analysis of adenylation and condensatio ... | 2008 | 17993540 |
| massetolide a biosynthesis in pseudomonas fluorescens. | massetolide a is a cyclic lipopeptide (clp) antibiotic produced by various pseudomonas strains from diverse environments. cloning, sequencing, site-directed mutagenesis, and complementation showed that massetolide a biosynthesis in p. fluorescens ss101 is governed by three nonribosomal peptide synthetase (nrps) genes, designated massa, massb, and massc, spanning approximately 30 kb. prediction of the nature and configuration of the amino acids by in silico analysis of adenylation and condensatio ... | 2008 | 17993540 |
| argonaute4 is required for resistance to pseudomonas syringae in arabidopsis. | here, we report the characterization of the arabidopsis thaliana ocp11 (for overexpressor of cationic peroxidase11) mutant, in which a beta-glucuronidase reporter gene under the control of the h(2)o(2)-responsive ep5c promoter is constitutively expressed. ocp11 plants show enhanced disease susceptibility to the virulent bacterium pseudomonas syringae pv tomato dc3000 (p.s.t. dc3000) and also to the avirulent p.s.t. dc3000 carrying the effector avrrpm1 gene. in addition, ocp11 plants are also com ... | 2007 | 17993621 |
| separation of plant pathogens from different hosts and tissues by capillary electromigration techniques. | in this contribution capillary isoelectric focusing and capillary zone electrophoresis were applied for the separation and detection of different plant pathogens including pseudomonas syringae pv. syringae, p. syringae pv. lachrymans, pseudomonas savastanoi pv. fraxinus, p. savastanoi pv. olea, agrobacterium tumefaciens, a vitis, xanthomonas arboricola pv. juglandis, x. campestris pv. zinniae, and curtobacterium sp.. the uv detection and sensitive fluorescence detection of the native phytopathog ... | 2007 | 17997525 |
| regulation of tradeoffs between plant defenses against pathogens with different lifestyles. | plants activate distinct defense responses depending on the lifestyle of the attacker encountered. in these responses, salicylic acid (sa) and jasmonic acid (ja) play important signaling roles. sa induces defense against biotrophic pathogens that feed and reproduce on live host cells, whereas ja activates defense against necrotrophic pathogens that kill host cells for nutrition and reproduction. cross-talk between these defense signaling pathways has been shown to optimize the response against a ... | 2007 | 17998535 |
| early detection of bean infection by pseudomonas syringae in asymptomatic leaf areas using chlorophyll fluorescence imaging. | chlorophyll fluorescence imaging has been used to analyse the response elicited in phaseolus vulgaris after inoculation with pseudomonas syringae pv. phaseolicola 1448a (compatible interaction) and p. syringae pv. tomato dc3000 (incompatible interaction). with the aim of modulating timing of symptom development, different cell densities were used to inoculate bean plants and the population dynamics of both bacterial strains was followed within the leaf tissue. fluorescence quenching analysis was ... | 2008 | 18000760 |
| a novel class of bacteria-induced small rnas in arabidopsis. | small rnas, including micrornas (mirnas) and small interfering rnas (sirnas), are essential regulatory molecules of many cellular processes. arabidopsis has at least three classes of endogenous sirnas--chromatin-associated sirnas, trans-acting sirnas (tasirnas), and natural antisense transcript (nat)-associated sirnas (nat-sirnas)--all 20-25 nucleotides (nt) in length. here, we identified a novel class of small rnas, long sirnas (lsirnas), which are 30-40 nt and share many common features with k ... | 2007 | 18003861 |
| the developmental selector as1 is an evolutionarily conserved regulator of the plant immune response. | the myb-related gene asymmetric leaves 1 (as1) and its orthologs have an evolutionarily conserved role in specification of leaf cell identity. as1 is expressed in leaf founder cells, where it functions as a heterodimer with the structurally unrelated as2 proteins to repress activity of knotted 1-like homeobox (knox) genes. as1 therefore confines knox activity to the shoot apical meristem, where it promotes stem cell function through the regulation of phytohormone activities. here, we show that l ... | 2007 | 18003921 |
| interplay between mamp-triggered and sa-mediated defense responses. | plants respond to pathogen infection using an innate immune system with at least two distinct recognition mechanisms. one mechanism recognizes microbe-associated molecular patterns (mamps). the other is based on resistance (r) genes and specifically recognizes certain pathogen virulence factors, including those delivered through the type iii secretion system (ttss) of bacteria. salicylic acid (sa)-mediated responses are an important part of the r gene-mediated defense. substantial overlaps betwe ... | 2008 | 18005228 |
| a pseudomonas syringae effector inactivates mapks to suppress pamp-induced immunity in plants. | pathogen-associated molecular patterns (pamps) elicit basal defense responses in plants, and, in turn, pathogens have evolved mechanisms to overcome these pamp-induced defenses. to suppress immunity, the phytopathogenic bacterium pseudomonas syringae secretes effector proteins, the biochemical function and virulence targets of which remain largely unknown. we show that hopai1, an effector widely conserved in both plant and animal bacterial pathogens, inhibits the arabidopsis mitogen-activated pr ... | 2007 | 18005697 |
| electron cryo-tomographic structure of cystovirus phi 12. | bacteriophage phi 12 is a member of the cystoviridae virus family and contains a genome consisting of three segments of double-stranded rna (dsrna). this virus family contains eight identified members, of which four have been classified in regard to their complete genomic sequence and encoded viral proteins. a phospholipid envelope that contains the integral proteins p6, p9, p10, and p13 surrounds the viral particles. in species phi 6, host infection requires binding of a multimeric p3 complex t ... | 2008 | 18022662 |
| electron cryo-tomographic structure of cystovirus phi 12. | bacteriophage phi 12 is a member of the cystoviridae virus family and contains a genome consisting of three segments of double-stranded rna (dsrna). this virus family contains eight identified members, of which four have been classified in regard to their complete genomic sequence and encoded viral proteins. a phospholipid envelope that contains the integral proteins p6, p9, p10, and p13 surrounds the viral particles. in species phi 6, host infection requires binding of a multimeric p3 complex t ... | 2008 | 18022662 |
| functional analysis of the role of fur in the virulence of pseudomonas syringae pv. tabaci 11528: fur controls expression of genes involved in quorum-sensing. | in most bacteria, fur (ferric uptake regulator) is a crucial global regulator known to operate not only in the regulation of iron homeostasis but also in a variety of other cellular processes. in an effort to characterize the role of fur in the virulence of plant pathogens, a fur homolog was isolated from pseudomonas syringae pv. tabaci 11528. phenotype assays showed that a fur deletion mutant (bl33) constitutively produced siderophore(s) and exhibited decreases in swarming motility as well as t ... | 2008 | 18023417 |
| regulation of motility by the expr/sin quorum-sensing system in sinorhizobium meliloti. | a successful symbiotic relationship between sinorhizobium meliloti and its host medicago sativa (alfalfa) depends on several signaling mechanisms, such as the biosynthesis of exopolysaccharides (eps) by s. meliloti. previous work in our laboratory has shown that a quorum-sensing mechanism controls the production of the symbiotically active eps ii. recent microarray analysis of the whole-genome expression profile of s. meliloti reveals that the expr/sin quorum-sensing system regulates additional ... | 2008 | 18024512 |
| regulation of motility by the expr/sin quorum-sensing system in sinorhizobium meliloti. | a successful symbiotic relationship between sinorhizobium meliloti and its host medicago sativa (alfalfa) depends on several signaling mechanisms, such as the biosynthesis of exopolysaccharides (eps) by s. meliloti. previous work in our laboratory has shown that a quorum-sensing mechanism controls the production of the symbiotically active eps ii. recent microarray analysis of the whole-genome expression profile of s. meliloti reveals that the expr/sin quorum-sensing system regulates additional ... | 2008 | 18024512 |
| effects of glycosylation on swimming ability and flagellar polymorphic transformation in pseudomonas syringae pv. tabaci 6605. | the role of flagellin glycosylation on motility was investigated in pseudomonas syringae pv. tabaci. the swimming activity of glycosylation-defective mutants was prominently decreased in a highly viscous medium. the mutants showed differences in polymorphic transitions and in the bundle formation of flagella, indicating that glycosylation stabilizes the filament structure and lubricates the rotation of the bundle. | 2008 | 18024523 |
| effects of glycosylation on swimming ability and flagellar polymorphic transformation in pseudomonas syringae pv. tabaci 6605. | the role of flagellin glycosylation on motility was investigated in pseudomonas syringae pv. tabaci. the swimming activity of glycosylation-defective mutants was prominently decreased in a highly viscous medium. the mutants showed differences in polymorphic transitions and in the bundle formation of flagella, indicating that glycosylation stabilizes the filament structure and lubricates the rotation of the bundle. | 2008 | 18024523 |
| preliminary investigations on inducing salt tolerance in maize through inoculation with rhizobacteria containing acc deaminase activity. | twenty rhizobacterial strains containing 1-aminocyclopropane-1-carboxylate deaminase were isolated from the rhizosphere of salt-affected maize fields. they were screened for their growth-promoting activities under axenic conditions at 1, 4, 8, and 12 ds x m-1 salinity levels. based upon the data of the axenic study, the 6 most effective strains were selected to conduct pot trials in the wire house. besides one original salinity level (1.6 ds x m-1), 3 other salinity levels (4, 8, and 12 ds x m-1 ... | 2007 | 18026206 |
| identification of prophages in bacterial genomes by dinucleotide relative abundance difference. | prophages are integrated viral forms in bacterial genomes that have been found to contribute to interstrain genetic variability. many virulence-associated genes are reported to be prophage encoded. present computational methods to detect prophages are either by identifying possible essential proteins such as integrases or by an extension of this technique, which involves identifying a region containing proteins similar to those occurring in prophages. these methods suffer due to the problem of l ... | 2007 | 18030328 |
| pathogen resistance of transgenic tobacco plants producing caffeine. | caffeine (1,3,7-trimethylxanthine) is a typical purine alkaloid, and produced by a variety of plants such as coffee and tea. its physiological function, however, is not completely understood, but chemical defense against pathogens and herbivores, and allelopathic effects against competing plant species have been proposed. previously, we constructed transgenic tobacco plants, which produced caffeine up to 5 microg per gram fresh weight of leaves, and showed them to repel caterpillars of tobacco c ... | 2008 | 18036626 |
| bioinformatic evaluation of l-arginine catabolic pathways in 24 cyanobacteria and transcriptional analysis of genes encoding enzymes of l-arginine catabolism in the cyanobacterium synechocystis sp. pcc 6803. | so far very limited knowledge exists on l-arginine catabolism in cyanobacteria, although six major l-arginine-degrading pathways have been described for prokaryotes. thus, we have performed a bioinformatic analysis of possible l-arginine-degrading pathways in cyanobacteria. further, we chose synechocystis sp. pcc 6803 for a more detailed bioinformatic analysis and for validation of the bioinformatic predictions on l-arginine catabolism with a transcript analysis. | 2007 | 18045455 |
| calcium efflux as a component of the hypersensitive response of nicotiana benthamiana to pseudomonas syringae. | using a model plant nicotiana benthamiana, we have demonstrated that initial calcium uptake in response to the hr (hypersensitive response)-causing pathogen pseudomonas syringae pv syringae 61 is followed by net calcium efflux initiated at about 12 h after the bacterial challenge and sustained for at least 48 h. our data suggest that calcium not only acts as an important second messenger in the activation of resistance responses but may also be a downstream mediator of later cell death accelerat ... | 2008 | 18048411 |
| proteomic analysis of the proteins regulated by hrpb from the plant pathogenic bacterium burkholderia glumae. | plant pathogenic bacteria transfer effector proteins into plant cells via the hypersensitive response and pathogenicity (hrp) type iii protein secretion system (t3ss) during infection. the genes encoding the hrp t3ss are expressed only under plant apoplast-mimicking conditions in an arac-type transcriptional activator hrpb-dependent manner. to identify the proteins controlled by hrpb in burkholderia glumae in vitro, we constitutively expressed hrpb and analyzed the proteins showing altered expre ... | 2008 | 18050277 |
| ectopic expression of apple mbr7 gene induced enhanced resistance to transgenic arabidopsis plant against a virulent pathogen. | a disease resistance related gene, mbr7, was identified in the wild apple species, malus baccata. the mbr7 gene has a single open reading frame (orf) of 3,288 nucleotides potentially encoding a 1,095-amino acid protein. its deduced amino acid sequence resembles the n protein of tobacco and the nl27 gene of potato and has several motifs characteristic of a tir-nbs-lrr r gene subclass. ectopic expression of mbr7 in arabidopsis enhanced the resistance against a virulent pathogen, pseudomonas syring ... | 2007 | 18051364 |
| a two-strain mixture of rhizobacteria elicits induction of systemic resistance against pseudomonas syringae and cucumber mosaic virus coupled to promotion of plant growth on arabidopsis thaliana. | we evaluated a commercial biopreparation of plant growth-promoting rhizobacteria (pgpr) strains bacillus subtilis gb03 and b. amyloliquefaciens in937a formulated with the carrier chitosan (bioyield) for its capacity to elicit growth promotion and induced systemic resistance against infection by cucumber mosaic virus (cmv) and pseudomonas syringae pv. tomato dc3000 in arabidopsis thaliana. the biopreparation promoted plant growth of arabidopsis hormonal mutants, which included auxin, gibberellic ... | 2007 | 18051759 |
| identification of two catalases in azotobacter vinelandii: a katg homologue and a novel bacterial cytochrome c catalase, cccav. | azotobacter vinelandii produces two detectable catalases during growth on minimal medium. the heat-labile catalase expressed during exponential growth phase was identified as a katg homologue by liquid chromatography-tandem mass spectrometry (lc-ms/ms) using a mixed protein sample. the second catalase was heat resistant and had substantial residual activity after treatment at 90 degrees c. this enzyme was purified by anion-exchange and size exclusion chromatography and was found to exhibit stron ... | 2008 | 18055590 |
| identification of two catalases in azotobacter vinelandii: a katg homologue and a novel bacterial cytochrome c catalase, cccav. | azotobacter vinelandii produces two detectable catalases during growth on minimal medium. the heat-labile catalase expressed during exponential growth phase was identified as a katg homologue by liquid chromatography-tandem mass spectrometry (lc-ms/ms) using a mixed protein sample. the second catalase was heat resistant and had substantial residual activity after treatment at 90 degrees c. this enzyme was purified by anion-exchange and size exclusion chromatography and was found to exhibit stron ... | 2008 | 18055590 |
| pseudomonas syringae type iii effector avrrpt2 alters arabidopsis thaliana auxin physiology. | the pseudomonas syringae type iii effector avrrpt2 promotes bacterial virulence on arabidopsis thaliana plants lacking a functional rps2 gene (rps2 mutant plants). to investigate the mechanisms underlying the virulence activity of avrrpt2, we examined the phenotypes of transgenic a. thaliana rps2 seedlings constitutively expressing avrrpt2. these seedlings exhibited phenotypes reminiscent of a. thaliana mutants with altered auxin physiology, including longer primary roots, increased number of la ... | 2007 | 18056646 |
| 62-kb plasmids harboring rulab homologues confer uv-tolerance and epiphytic fitness to pseudomonas syringae pv. syringae mango isolates. | the presence of genetic determinants homologous to rulab genes for ultraviolet (uv) radiation resistance was determined in a collection of pseudomonas syringae pv. syringae strains isolated from mango. the potential role of these plasmids in uv tolerance and ecological fitness in the mango phyllosphere was also evaluated. nearly all of the 62-kb plasmids present in the p. syringae pv. syringae strains hybridized with a rulab probe, but these 62-kb plasmids showed differences in restriction patte ... | 2008 | 18058161 |
| structure and dynamics of the antifungal molecules syringotoxin-b and syringopeptin-25a from molecular dynamics simulation. | the phytopathogen pseudomonas syringae pv. syringae produces toxic cyclic lipodepsipeptides (clps): nona-peptides and syringopeptins. all clps inhibit the growth of many fungal species, including human pathogens, although different fungi display different degrees of sensitivity. the best studied clps are syringomycin-e (sr-e), syringotoxin-b (st-b) and syringopeptin-25a (sp-25a). their biological activity is affected by membrane composition and their structural differences. we previously (matyus ... | 2008 | 18064450 |
| expression of two old yellow enzyme homologues from gluconobacter oxydans and identification of their citral hydrogenation abilities. | two genes that encode proteins which share 30-35% sequence identity with yeast oye (old yellow enzyme, an nad(p)h fmn-oxidoreductase), the well-studied archetype of the oye protein family, have been identified in gluconobacter oxydans m5. the two genes are localized in the chromosome and plasmid, respectively. comparison of the deduced amino acid sequences of the enzymes with database entries revealed 75.1% similarity and 64.9% identity to that of the pseudomonas syringae pv. glycinea nad(p)h-de ... | 2008 | 18064575 |
| interplay of different transporters in the mediation of divalent heavy metal resistance in pseudomonas putida kt2440. | according to in silico analysis, the genome of pseudomonas putida kt2440 encodes at least four zn/cd/pb efflux transporters-two p-type atpases (cada1 and cada2) and two czc chemiosmotic transporters (czccba1 and czccba2). in this study we showed that all these transporters are functional, but under laboratory conditions only two of them were involved in the mediation of heavy metal resistance in p. putida kt2440. cada2 conferred cd(2+) and pb(2+) resistance, whereas czccba1 was involved in expor ... | 2008 | 18065533 |
| interplay of different transporters in the mediation of divalent heavy metal resistance in pseudomonas putida kt2440. | according to in silico analysis, the genome of pseudomonas putida kt2440 encodes at least four zn/cd/pb efflux transporters-two p-type atpases (cada1 and cada2) and two czc chemiosmotic transporters (czccba1 and czccba2). in this study we showed that all these transporters are functional, but under laboratory conditions only two of them were involved in the mediation of heavy metal resistance in p. putida kt2440. cada2 conferred cd(2+) and pb(2+) resistance, whereas czccba1 was involved in expor ... | 2008 | 18065533 |
| moraxella catarrhalis synthesizes an autotransporter that is an acid phosphatase. | moraxella catarrhalis o35e was shown to synthesize a 105-kda protein that has similarity to both acid phosphatases and autotransporters. the n-terminal portion of the m. catarrhalis acid phosphatase a (mapa) was most similar (the blast probability score was 10(-10)) to bacterial class a nonspecific acid phosphatases. the central region of the mapa protein had similarity to passenger domains of other autotransporter proteins, whereas the c-terminal portion of mapa resembled the translocation doma ... | 2008 | 18065547 |
| moraxella catarrhalis synthesizes an autotransporter that is an acid phosphatase. | moraxella catarrhalis o35e was shown to synthesize a 105-kda protein that has similarity to both acid phosphatases and autotransporters. the n-terminal portion of the m. catarrhalis acid phosphatase a (mapa) was most similar (the blast probability score was 10(-10)) to bacterial class a nonspecific acid phosphatases. the central region of the mapa protein had similarity to passenger domains of other autotransporter proteins, whereas the c-terminal portion of mapa resembled the translocation doma ... | 2008 | 18065547 |
| firefly luciferase complementation imaging assay for protein-protein interactions in plants. | the development of sensitive and versatile techniques to detect protein-protein interactions in vivo is important for understanding protein functions. the previously described techniques, fluorescence resonance energy transfer and bimolecular fluorescence complementation, which are used widely for protein-protein interaction studies in plants, require extensive instrumentation. to facilitate protein-protein interaction studies in plants, we adopted the luciferase complementation imaging assay. t ... | 2008 | 18065554 |
| transgenic expression of a fungal endo-polygalacturonase increases plant resistance to pathogens and reduces auxin sensitivity. | polygalacturonases (pgs), enzymes that hydrolyze the homogalacturonan of the plant cell wall, are virulence factors of several phytopathogenic fungi and bacteria. on the other hand, pgs may activate defense responses by releasing oligogalacturonides (ogs) perceived by the plant cell as host-associated molecular patterns. tobacco (nicotiana tabacum) and arabidopsis (arabidopsis thaliana) plants expressing a fungal pg (pg plants) have a reduced content of homogalacturonan. here, we show that pg pl ... | 2008 | 18065558 |
| interaction between sgt1 and cytosolic/nuclear hsc70 chaperones regulates arabidopsis immune responses. | the conserved eukaryotic protein sgt1 (for suppressor of g2 allele of skp1) has characteristics of an hsp90 (for heat shock protein 90 kd) cochaperone and in plants regulates hormone responses and resistance gene-triggered immunity. we affinity-purified sgt1-interacting proteins from arabidopsis thaliana leaf extracts and identified by mass spectrometry cytosolic heat shock cognate 70 (hsc70) chaperones as the major stable sgt1 interactors. arabidopsis sgt1a and sgt1b proteins associate with hsc ... | 2007 | 18065690 |
| atnfxl1, an arabidopsis homologue of the human transcription factor nf-x1, functions as a negative regulator of the trichothecene phytotoxin-induced defense response. | trichothecenes are a closely related family of phytotoxins that are produced by phytopathogenic fungi. in arabidopsis, expression of atnfxl1, a homologue of the putative human transcription repressor nf-x1, was significantly induced by application of type a trichothecenes, such as t-2 toxin. an atnfxl1 mutant growing on medium lacking trichothecenes showed no phenotype, whereas a hypersensitivity phenotype was observed in t-2 toxin-treated atnfxl1 mutant plants. microarray analysis indicated tha ... | 2008 | 18069941 |
| complete dna sequence and analysis of the transferable multiple-drug resistance plasmids (r plasmids) from photobacterium damselae subsp. piscicida isolates collected in japan and the united states. | photobacterium damselae subsp. piscicida is a bacterial fish pathogen that causes a disease known as pasteurellosis. two transferable multiple-drug resistance (r) plasmids, pp99-018 (carrying resistance to kanamycin, chloramphenicol, tetracycline, and sulfonamide) and pp91278 (carrying resistance to tetracycline, trimethoprim, and sulfonamide), isolated from p. damselae subsp. piscicida strains from japan (p99-018) and the united states (p91278), respectively, were completely sequenced and analy ... | 2008 | 18070959 |
| complete dna sequence and analysis of the transferable multiple-drug resistance plasmids (r plasmids) from photobacterium damselae subsp. piscicida isolates collected in japan and the united states. | photobacterium damselae subsp. piscicida is a bacterial fish pathogen that causes a disease known as pasteurellosis. two transferable multiple-drug resistance (r) plasmids, pp99-018 (carrying resistance to kanamycin, chloramphenicol, tetracycline, and sulfonamide) and pp91278 (carrying resistance to tetracycline, trimethoprim, and sulfonamide), isolated from p. damselae subsp. piscicida strains from japan (p99-018) and the united states (p91278), respectively, were completely sequenced and analy ... | 2008 | 18070959 |
| modulation of bacterial type iii secretion system by a spermidine transporter dependent signaling pathway. | many gram-negative bacterial pathogens employ type iii secretion systems (t3ss) to inject effector proteins into host cells in infectious processes. | 2007 | 18074016 |
| gac two-component system in pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction. | pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. to investigate the regulatory mechanism of the expression of virulence, gac two-component system-defective mutants, deltagaca and deltagacs, and a double mutant, deltagacadeltagacs, were generated. these mutants produced smaller amounts of n-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algt gene required for ex ... | 2008 | 18080141 |
| structure and function of pa4872 from pseudomonas aeruginosa, a novel class of oxaloacetate decarboxylase from the pep mutase/isocitrate lyase superfamily. | pseudomonas aeruginosa pa4872 was identified by sequence analysis as a structurally and functionally novel member of the pep mutase/isocitrate lyase superfamily and therefore targeted for investigation. substrate screens ruled out overlap with known catalytic functions of superfamily members. the crystal structure of pa4872 in complex with oxalate (a stable analogue of the shared family alpha-oxyanion carboxylate intermediate/transition state) and mg2+ was determined at 1.9 a resolution. as with ... | 2008 | 18081320 |
| structure and function of pa4872 from pseudomonas aeruginosa, a novel class of oxaloacetate decarboxylase from the pep mutase/isocitrate lyase superfamily. | pseudomonas aeruginosa pa4872 was identified by sequence analysis as a structurally and functionally novel member of the pep mutase/isocitrate lyase superfamily and therefore targeted for investigation. substrate screens ruled out overlap with known catalytic functions of superfamily members. the crystal structure of pa4872 in complex with oxalate (a stable analogue of the shared family alpha-oxyanion carboxylate intermediate/transition state) and mg2+ was determined at 1.9 a resolution. as with ... | 2008 | 18081320 |
| the pseudomonas aeruginosa type iii secretion system plays a dual role in the regulation of caspase-1 mediated il-1beta maturation. | pseudomonas aeruginosa is an opportunistic bacterial pathogen that forms a serious problem for immunocompromised patients and also the leading cause of mortality in cystic fibrosis. the overall importance of a functional type iii secretion system (t3ss) in p. aeruginosa virulence has been well established, but the underlying mechanisms are still unclear. using in vitro infected macrophages as w as a murine model of acute lung infection, we show that the caspase-1 mediated maturation and secretio ... | 2008 | 18081695 |
| the pseudomonas aeruginosa type iii secretion system plays a dual role in the regulation of caspase-1 mediated il-1beta maturation. | pseudomonas aeruginosa is an opportunistic bacterial pathogen that forms a serious problem for immunocompromised patients and also the leading cause of mortality in cystic fibrosis. the overall importance of a functional type iii secretion system (t3ss) in p. aeruginosa virulence has been well established, but the underlying mechanisms are still unclear. using in vitro infected macrophages as w as a murine model of acute lung infection, we show that the caspase-1 mediated maturation and secretio ... | 2008 | 18081695 |
| natural variation in rps2-mediated resistance among arabidopsis accessions: correlation between gene expression profiles and phenotypic responses. | natural variation in gene expression (expression traits or e-traits) is increasingly used for the discovery of genes controlling traits. an important question is whether a particular e-trait is correlated with a phenotypic trait. here, we examined the correlations between phenotypic traits and e-traits among 10 arabidopsis thaliana accessions. we studied defense against pseudomonas syringae pv tomato dc3000 (pst), with a focus on resistance gene-mediated resistance triggered by the type iii effe ... | 2007 | 18083910 |
| fuscopeptins, antimicrobial lipodepsipeptides from pseudomonas fuscovaginae, are channel forming peptides active on biological and model membranes. | fp-a and fp-b are ldps produced by the plant pathogen pseudomonas fuscovaginae. as expected from their primary structure, they shared a similar mechanism of action with the better characterized sps, synthesized by strains of pseudomonas syringae pv. syringae. indeed, they displayed hemolytic activity on human erythrocytes and were able to induce calcein release from luvs: the effect was dependent on the concentration of the fps and the lipid composition of the liposome and, in particular, it inc ... | 2008 | 18085513 |
| plastid omega3-fatty acid desaturase-dependent accumulation of a systemic acquired resistance inducing activity in petiole exudates of arabidopsis thaliana is independent of jasmonic acid. | systemic acquired resistance (sar) is an inducible defense mechanism that is activated throughout the plant, subsequent to localized inoculation with a pathogen. the establishment of sar requires translocation of an unknown signal from the pathogen-inoculated leaf to the distal organs, where salicylic acid-dependent defenses are activated. we demonstrate here that petiole exudates (pexs) collected from arabidopsis leaves inoculated with an avirulent (avr) pseudomonas syringae strain promote resi ... | 2008 | 18088304 |
| interplay between ja, sa and aba signalling during basal and induced resistance against pseudomonas syringae and alternaria brassicicola. | we have examined the role of the callose synthase pmr4 in basal resistance and beta-aminobutyric acid-induced resistance (baba-ir) of arabidopsis thaliana against the hemi-biotrophic pathogen pseudomonas syringae and the necrotrophic pathogen alternaria brassicicola. compared to wild-type plants, the pmr4-1 mutant displayed enhanced basal resistance against p. syringae, which correlated with constitutive expression of the pr-1 gene. treating the pmr4-1 mutant with baba boosted the already elevat ... | 2008 | 18088307 |
| three-dimensional models of nb-arc domains of disease resistance proteins in tomato, arabidopsis, and flax. | three dimensional models of nb-arc domains in five different proteins were constructed based on the recently published crystal structure of the apoptotic protease activating factor 1, of which two are for tomato species, one each for flax, arabidopsis, and nematode. standard multiple sequence alignment was performed for chosen members of the nb-arc domains, very divergent from each other in protein sequence, followed by homology model building and structure refinement. in this alignment, amino a ... | 2008 | 18092830 |
| rar1 and hsp90 form a complex with rac/rop gtpase and function in innate-immune responses in rice. | a rice (oryza sativa) rac/rop gtpase, os rac1, is involved in innate immunity, but its molecular function is largely unknown. rar1 (for required for mla12 resistance) and hsp90 (a heat shock protein 90 kd) are important components of r gene-mediated disease resistance, and their function is conserved in several plant species. hsp90 has also recently been shown to be important in mammalian innate immunity. however, their functions at the molecular level are not well understood. in this study, we ... | 2007 | 18156216 |
| pseudomonas syringae bett is a low-affinity choline transporter that is responsible for superior osmoprotection by choline over glycine betaine. | the plant pathogen pseudomonas syringae derives better osmoprotection from choline than from glycine betaine, unlike most bacteria that have been characterized. in this report, we identified a betaine/carnitine/choline family transporter (bcct) in p. syringae pv. tomato strain dc3000 that mediates the transport of choline and acetylcholine. this transporter has a particularly low affinity (k(m) of 876 microm) and high capacity (v(max) of 80 nmol/min/mg of protein) for choline transport relative ... | 2008 | 18156257 |
| pseudomonas syringae bett is a low-affinity choline transporter that is responsible for superior osmoprotection by choline over glycine betaine. | the plant pathogen pseudomonas syringae derives better osmoprotection from choline than from glycine betaine, unlike most bacteria that have been characterized. in this report, we identified a betaine/carnitine/choline family transporter (bcct) in p. syringae pv. tomato strain dc3000 that mediates the transport of choline and acetylcholine. this transporter has a particularly low affinity (k(m) of 876 microm) and high capacity (v(max) of 80 nmol/min/mg of protein) for choline transport relative ... | 2008 | 18156257 |
| salicylic acid and systemic acquired resistance play a role in attenuating crown gall disease caused by agrobacterium tumefaciens. | we investigated the effects of salicylic acid (sa) and systemic acquired resistance (sar) on crown gall disease caused by agrobacterium tumefaciens. nicotiana benthamiana plants treated with sa showed decreased susceptibility to agrobacterium infection. exogenous application of sa to agrobacterium cultures decreased its growth, virulence, and attachment to plant cells. using agrobacterium whole-genome microarrays, we characterized the direct effects of sa on bacterial gene expression and showed ... | 2008 | 18156296 |
| pseudomonas syringae effector avrpto blocks innate immunity by targeting receptor kinases. | plants use receptor kinases, such as fls2 and efr, to perceive bacterial pathogens and initiate innate immunity. this immunity is often suppressed by bacterial effectors, allowing pathogen propagation. to counteract, plants have evolved disease resistance genes that detect the bacterial effectors and reinstate resistance. the pseudomonas syringae effector avrpto promotes infection in susceptible plants but triggers resistance in plants carrying the protein kinase pto and the associated resistanc ... | 2008 | 18158241 |
| the complete genome sequence and analysis of the epsilonproteobacterium arcobacter butzleri. | arcobacter butzleri is a member of the epsilon subdivision of the proteobacteria and a close taxonomic relative of established pathogens, such as campylobacter jejuni and helicobacter pylori. here we present the complete genome sequence of the human clinical isolate, a. butzleri strain rm4018. | 2007 | 18159241 |
| pseudomonas 2007. | | 2008 | 18165299 |
| pseudomonas 2007. | | 2008 | 18165299 |
| the downy mildew effector proteins atr1 and atr13 promote disease susceptibility in arabidopsis thaliana. | the downy mildew (hyaloperonospora parasitica) effector proteins atr1 and atr13 trigger rpp1-nd/wsb- and rpp13-nd-dependent resistance, respectively, in arabidopsis thaliana. to better understand the functions of these effectors during compatible and incompatible interactions of h. parasitica isolates on arabidopsis accessions, we developed a novel delivery system using pseudomonas syringae type iii secretion via fusions of atrs to the n terminus of the p. syringae effector protein, avrrps4. atr ... | 2007 | 18165328 |
| detection of plant-modulated alterations in antifungal gene expression in pseudomonas fluorescens cha0 on roots by flow cytometry. | the biocontrol activity of the root-colonizing pseudomonas fluorescens strain cha0 is largely determined by the production of antifungal metabolites, especially 2,4-diacetylphloroglucinol. the expression of these metabolites depends on abiotic and biotic environmental factors, in particular, elements present in the rhizosphere. in this study, we have developed a new method for the in situ analysis of antifungal gene expression using flow cytometry combined with green fluorescent protein (gfp)-ba ... | 2008 | 18165366 |
| detection of plant-modulated alterations in antifungal gene expression in pseudomonas fluorescens cha0 on roots by flow cytometry. | the biocontrol activity of the root-colonizing pseudomonas fluorescens strain cha0 is largely determined by the production of antifungal metabolites, especially 2,4-diacetylphloroglucinol. the expression of these metabolites depends on abiotic and biotic environmental factors, in particular, elements present in the rhizosphere. in this study, we have developed a new method for the in situ analysis of antifungal gene expression using flow cytometry combined with green fluorescent protein (gfp)-ba ... | 2008 | 18165366 |
| comparative expression analysis of genes induced during development of bacterial rot and induction of hypersensitive cell death in lettuce. | the development of bacterial rot disease caused by pseudomonas cichorii is closely associated with programmed cell death. to investigate the molecular events occurring during the development of bacterial rot, we isolated 20 p. cichorii-responsive genes (pcrgs) in lettuce by differential display. among these pcrgs, signal transduction-, transcription/translation- and defense/stress responses-related pcrgs were subjected to a comparative expression study. we used rna samples isolated from lettuce ... | 2008 | 18171591 |
| expression of a ring-hc protein from rice improves resistance to pseudomonas syringae pv. tomato dc3000 in transgenic arabidopsis thaliana. | a cdna clone (osrhc1) was obtained, which encodes a novel ring zinc finger protein sharing similar structural features (multiple transmembrane domains at the n-half; a unique ring zinc finger consensus cys-x(2)-cys-x(11)-cys-x-his-x(3)-cys-x(2)-cys-x(6)-cys-x(2)-cys at the c terminus) to a group of closely related annotated proteins from both monocots and dicots. osrhc1 was found to be localized on plasma membrane of rice cells and induced by wounding in rice lines containing xa loci. ecotopic e ... | 2007 | 18182423 |
| simultaneous interaction of arabidopsis thaliana with bradyrhizobium sp. strain ors278 and pseudomonas syringae pv. tomato dc3000 leads to complex transcriptome changes. | induced systemic resistance (isr) is a process elicited by telluric microbes, referred to as plant growth-promoting rhizobacteria (pgpr), that protect the host plant against pathogen attacks. isr has been defined from studies using pseudomonas strains as the biocontrol agent. here, we show for the first time that a photosynthetic bradyrhizobium sp. strain, ors278, also exhibits the ability to promote isr in arabidopsis thaliana, indicating that the isr effect may be a widespread ability. to inve ... | 2008 | 18184068 |
| pseudomonas syringae pv. tomato dc3000 uses constitutive and apoplast-induced nutrient assimilation pathways to catabolize nutrients that are abundant in the tomato apoplast. | the plant apoplast is the intercellular space that surrounds plant cells, in which metabolic and physiological processes relating to cell wall biosynthesis, nutrient transport, and stress responses occur. the apoplast is also the primary site of infection for hemibiotrophic pathogens such as p. syringae, which obtain nutrients directly from apoplastic fluid. we have used apoplastic fluid extracted from healthy tomato leaves as a growth medium for pseudomonas spp. in order to investigate the role ... | 2008 | 18184070 |
| the life history of the plant pathogen pseudomonas syringae is linked to the water cycle. | pseudomonas syringae is a plant pathogen well known for its capacity to grow epiphytically on diverse plants and for its ice-nucleation activity. the ensemble of its known biology and ecology led us to postulate that this bacterium is also present in non-agricultural habitats, particularly those associated with water. here, we report the abundance of p. syringae in rain, snow, alpine streams and lakes and in wild plants, in addition to the previously reported abundance in epilithic biofilms. eac ... | 2008 | 18185595 |
| crt1, an arabidopsis atpase that interacts with diverse resistance proteins and modulates disease resistance to turnip crinkle virus. | plant immunity frequently involves the recognition of pathogen-encoded avirulence (avr) factors by their corresponding plant resistance (r) proteins. this triggers the hypersensitive response (hr) where necrotic lesions formed at the site(s) of infection help restrict pathogen spread. hrt is an arabidopsis r protein required for resistance to turnip crinkle virus (tcv). in a genetic screen for mutants compromised in the recognition of tcv's avr factor, we identified crt1 (compromised recognition ... | 2008 | 18191794 |
| lipase expression in pseudomonas alcaligenes is under the control of a two-component regulatory system. | preliminary observations in a large-scale fermentation process suggested that the lipase expression of pseudomonas alcaligenes can be switched on by the addition of certain medium components, such as soybean oil. in an attempt to elucidate the mechanism of induction of lipase expression, we have set up a search method for genes controlling lipase expression by use of a cosmid library containing fragments of p. alcaligenes genomic dna. a screen for lipase hyperproduction resulted in the selection ... | 2008 | 18192420 |
| activation of the indole-3-acetic acid-amido synthetase gh3-8 suppresses expansin expression and promotes salicylate- and jasmonate-independent basal immunity in rice. | new evidence suggests a role for the plant growth hormone auxin in pathogenesis and disease resistance. bacterial infection induces the accumulation of indole-3-acetic acid (iaa), the major type of auxin, in rice (oryza sativa). iaa induces the expression of expansins, proteins that loosen the cell wall. loosening the cell wall is key for plant growth but may also make the plant vulnerable to biotic intruders. here, we report that rice gh3-8, an auxin-responsive gene functioning in auxin-depende ... | 2008 | 18192436 |
| recognition of the hyaloperonospora parasitica effector atr13 triggers resistance against oomycete, bacterial, and viral pathogens. | phytopathogenic oomycetes cause some of the most devastating diseases affecting agricultural crops. hyaloperonospora parasitica is a native oomycete pathogen of arabidopsis and is related to other oomycete phytopathogens that include several species of phytophthora, including the causal agent of potato late blight. recently, four oomycete effector genes have been isolated, and several oomycete genomes have been sequenced. we have developed an efficient and genetically amenable system to test put ... | 2008 | 18198274 |
| optimized cdna libraries for virus-induced gene silencing (vigs) using tobacco rattle virus. | abstract: | 2008 | 18211705 |
| quantitative 1h nmr metabolomics reveals extensive metabolic reprogramming of primary and secondary metabolism in elicitor-treated opium poppy cell cultures. | opium poppy (papaver somniferum) produces a diverse array of bioactive benzylisoquinoline alkaloids and has emerged as a model system to study plant alkaloid metabolism. the plant is cultivated as the only commercial source of the narcotic analgesics morphine and codeine, but also produces many other alkaloids including the antimicrobial agent sanguinarine. modulations in plant secondary metabolism as a result of environmental perturbations are often associated with the altered regulation of oth ... | 2008 | 18211706 |
| the evolution of gene collectives: how natural selection drives chemical innovation. | dna sequencing has become central to the study of evolution. comparing the sequences of individual genes from a variety of organisms has revolutionized our understanding of how single genes evolve, but the challenge of analyzing polygenic phenotypes has complicated efforts to study how genes evolve when they are part of a group that functions collectively. we suggest that biosynthetic gene clusters from microbes are ideal candidates for the evolutionary study of gene collectives; these selfish g ... | 2008 | 18216259 |
| [antimicrobial activity of calendula l. plants]. | the sap of different organs of genus calendula plant species has been studied for antimicrobial activity. the sap of racemes demonstrated the most expressed antimicrobial effect while that of the roots - the least one. calendula species inhibited all tested pathogenic microorganisms, especially pseudomonas syringae, p. fluorescens, xanthomonas campestris, agrobacterium tumefaciens. calendula suffruticosa was the most active to all investigated microorganisms. | 2007 | 18217350 |
| myb72 is required in early signaling steps of rhizobacteria-induced systemic resistance in arabidopsis. | colonization of arabidopsis thaliana roots by nonpathogenic pseudomonas fluorescens wcs417r bacteria triggers a jasmonate/ethylene-dependent induced systemic resistance (isr) that is effective against a broad range of pathogens. microarray analysis revealed that the r2r3-myb-like transcription factor gene myb72 is specifically activated in the roots upon colonization by wcs417r. here, we show that t-dna knockout mutants myb72-1 and myb72-2 are incapable of mounting isr against the pathogens pseu ... | 2008 | 18218967 |
| genome-wide expression profiling arabidopsis at the stage of golovinomyces cichoracearum haustorium formation. | compatibility between plants and obligate biotrophic fungi requires fungal mechanisms for efficiently obtaining nutrients and counteracting plant defenses under conditions that are expected to induce changes in the host transcriptome. a key step in the proliferation of biotrophic fungi is haustorium differentiation. here we analyzed global gene expression patterns in arabidopsis thaliana leaves during the formation of haustoria by golovinomyces cichoracearum. at this time, the endogenous levels ... | 2008 | 18218973 |
| modulation of defense signal transduction by flagellin-induced wrky41 transcription factor in arabidopsis thaliana. | flagellin, a component of the flagellar filament of pseudomonas syringae pv. tabaci 6605 (pta), induces hypersensitive reaction in its non-host arabidopsis thaliana. we identified the wrky41 gene, which belongs to a multigene family encoding wrky plant-specific transcription factors, as one of the flagellin-inducible genes in a. thaliana. expression of wrky41 is induced by inoculation with the incompatible pathogen p. syringae pv. tomato dc3000 (pto) possessing avrrpt2 and the non-host pathogens ... | 2008 | 18219494 |
| overexpression of atsgt1, an arabidopsis salicylic acid glucosyltransferase, leads to increased susceptibility to pseudomonas syringae. | we reported previously that a recombinant salicylic acid (sa) glucosyltransferase1 (atsgt1) from arabidopsis thaliana catalyzes the formation of both sa 2-o-beta-d-glucoside (sag) and the glucose ester of sa (sge). here, transgenic arabidopsis plants overexpressing atsgt1 have been constructed, and their phenotypes analyzed. compared to wild-type plants, transgenic plants showed an increased susceptibility to pseudomonas syringae and reduced the accumulation levels of both free sa and its glucos ... | 2008 | 18226820 |
| the alternative sigma factor algt, but not alginate synthesis, promotes in planta multiplication of pseudomonas syringae pv. glycinea. | the phytopathogen pseudomonas syringae pv. glycinea produces the exopolysaccharide (eps) alginate, which is thought to function in epiphytic fitness and virulence. a key regulator for alginate biosynthesis in pseudomonas aeruginosa and p. syringae is the alternative sigma factor algt (sigma(22)). in this study, the contribution of alginate synthesis and algt to in planta epiphytic fitness and virulence of p. syringae was examined. alginate biosynthesis mutants were generated for the p. syringae ... | 2008 | 18227245 |
| functional role of the additional domains in inulosucrase (isla) from leuconostoc citreum cw28. | inulosucrase (isla) from leuconostoc citreum cw28 belongs to a new subfamily of multidomain fructosyltransferases (ftfs), containing additional domains from glucosyltransferases. it is not known what the function of the additional domains in this subfamily is. | 2008 | 18237396 |
| chemical and antibacterial constituents of skimmia anquetelia. | investigation of the leaves of skimmia anquetelia (rutaceae) led to the isolation of a new coumarin glucoside 7,8-dihdroxy-6-[3'-beta- d-glucopyranosyloxy-2'(xi)-hydroxy-3'-methylbutyl]-coumarin ( 1) together with five known coumarins: 6-(2,3-dihydroxy-3-methylbutyl)-7-methoxycoumarin ( 2), skimmin ( 3), osthol ( 4), esculetin ( 5) and scopuletin ( 6). the antibacterial activity of compounds 1 and 3 was also investigated against the plant bacterial pathogens agrobacterium tumifaciens, pseudomona ... | 2008 | 18240101 |
| tomato transcriptional changes in response to clavibacter michiganensis subsp. michiganensis reveal a role for ethylene in disease development. | clavibacter michiganensis subsp. michiganensis (cmm) is a gram-positive actinomycete, causing bacterial wilt and canker disease in tomato (solanum lycopersicum). host responses to gram-positive bacteria and molecular mechanisms associated with the development of disease symptoms caused by cmm in tomato are largely unexplored. to investigate plant responses activated during this compatible interaction, we used microarray analysis to monitor changes in host gene expression during disease developme ... | 2008 | 18245454 |
| hypericum perforatum plant cells reduce agrobacterium viability during co-cultivation. | plant recalcitrance is the major barrier in developing agrobacterium-mediated transformation protocols for several important plant species. despite the substantial knowledge of t-dna transfer process, very little is known about the factors leading to the plant recalcitrance. here, we analyzed the basis of hypericum perforatum l. (hp) recalcitrance to agrobacterium-mediated transformation using cell suspension culture. when challenged with agrobacterium, hp cells swiftly produced an intense oxida ... | 2008 | 18247048 |
| characteristic expression of twelve rice pr1 family genes in response to pathogen infection, wounding, and defense-related signal compounds (121/180). | pathogenesis-related (pr) proteins have been used as markers of plant defense responses, and are classified into 17 families. however, precise information on the majority members in specific pr families is still limited. we were interested in the individual characteristics of rice pr1 family genes, and selected 12 putatively active genes using rice genome databases for expressed genes. all were upregulated upon compatible and/or incompatible rice-blast fungus interactions; three were upregulated ... | 2008 | 18247056 |
| nmr structure of the peptidyl-trna hydrolase domain from pseudomonas syringae expands the structural coverage of the hydrolysis domains of class 1 peptide chain release factors. | | 2008 | 18247350 |
| auxotrophy in natural isolate: minimal requirements for growth of the antarctic psychrotrophic bacterium pseudomonas syringae lz4w. | a chemically defined minimal medium has been developed for growing the antarctic psychrotrophic bacterium pseudomonas syringae lz4w, a model system for studying cold adaptation. this natural isolate from antarctica has an absolute requirement for two branched chain amino acids, isoleucine and valine, in addition to low osmolality of the growth medium. the bacterium contains threonine deaminase but lacks acetohydroxyacid synthase suggesting that a defect lies in the isoleucine and valine biosynth ... | 2008 | 18247394 |
| a high-throughput chemical screen for resistance to pseudomonas syringae in arabidopsis. | the study of plant pathogenesis and the development of effective treatments to protect plants from diseases could be greatly facilitated by a high-throughput pathosystem to evaluate small-molecule libraries for inhibitors of pathogen virulence. the interaction between the gram-negative bacterium pseudomonas syringae and arabidopsis thaliana is a model for plant pathogenesis. however, a robust high-throughput assay to score the outcome of this interaction is currently lacking. we demonstrate that ... | 2008 | 18248597 |
| bacterial non-host resistance: interactions of arabidopsis with non-adapted pseudomonas syringae strains. | although interactions of plants with virulent and avirulent host pathogens are under intensive study, relatively little is known about plant interactions with non-adapted pathogens and the molecular events underlying non-host resistance. here we show that two pseudomonas syringae strains for which arabidopsis is a non-host plant, p. syringae pathovar (pv.) glycinea (psg) and p. syringae pv. phaseolicola (psp),induce salicylic acid (sa) accumulation and pathogenesis-related gene expression at ino ... | 2007 | 18251883 |
| characterization of antimicrobial compounds produced by pseudomonas aurantiaca s-1. | pseudomonas aurantiaca s-1 can serve as a natural source of pesticides towards phytopathogens like fusarium oxysporum p1 and pseudomonas syringae pv. glycinea bim b-280. the largest pool of produced antimicrobial compounds was found in four days-old spent culture supernatant. at least two groups of bioactive substances were identified, one responsible for the antibacterial activity and the other for the antifungal activity. the fraction with strong antibacterial activity had the molecular mass 2 ... | 2007 | 18254494 |
| the pseudomonas syringae type iii effector hopam1 enhances virulence on water-stressed plants. | pseudomonas syringae strains deliver diverse type iii effector proteins into host cells, where they can act as virulence factors. although the functions of the majority of type iii effectors are unknown, several have been shown to interfere with plant basal defense mechanisms. type iii effectors also could contribute to bacterial virulence by enhancing nutrient uptake and pathogen adaptation to the environment of the host plant. we demonstrate that the type iii effector hopam1 (formerly known as ... | 2008 | 18257685 |
| lcrg secretion is not required for blocking of yops secretion in yersinia pestis. | lcrg, a negative regulator of the yersinia type iii secretion apparatus has been shown to be primarily a cytoplasmic protein, but is secreted at least in y. pestis. lcrg secretion has not been functionally analyzed and the relevance of lcrg secretion on lcrg function is unknown. | 2008 | 18261225 |
| secretome analysis uncovers an hcp-family protein secreted via a type vi secretion system in agrobacterium tumefaciens. | agrobacterium tumefaciens is a plant-pathogenic bacterium capable of secreting several virulence factors into extracellular space or the host cell. in this study, we used shotgun proteomics analysis to investigate the secretome of a. tumefaciens, which resulted in identification of 12 proteins, including 1 known secretory protein (virb1*) and 11 potential secretory proteins. interestingly, one unknown protein, which we designated hemolysin-coregulated protein (hcp), is a predicted soluble protei ... | 2008 | 18263727 |
| the hopz family of pseudomonas syringae type iii effectors require myristoylation for virulence and avirulence functions in arabidopsis thaliana. | pseudomonas syringae utilizes the type iii secretion system to translocate effector proteins into plant cells, where they can contribute to the pathogen's ability to infect and cause disease. recognition of these effectors by resistance proteins induces defense responses that typically include a programmed cell death reaction called the hypersensitive response. the yopj/hopz family of type iii effector proteins is a common family of effector proteins found in animal- and plant-pathogenic bacteri ... | 2008 | 18263728 |
| naturally occurring nonpathogenic isolates of the plant pathogen pseudomonas syringae lack a type iii secretion system and effector gene orthologues. | pseudomonas syringae causes plant diseases, and the main virulence mechanism is a type iii secretion system (t3ss) that translocates dozens of effector proteins into plant cells. here we report the existence of a subgroup of p. syringae isolates that do not cause disease on any plant species tested. this group is monophyletic and most likely evolved from a pathogenic p. syringae ancestor through loss of the t3ss. in the nonpathogenic isolate p. syringae 508 the genomic region that in pathogenic ... | 2008 | 18263729 |