| uncoupling of reactive oxygen species accumulation and defence signalling in the metal hyperaccumulator plant noccaea caerulescens. | the metal hyperaccumulator plant noccaea caerulescens is protected from disease by the accumulation of high concentrations of metals in its aerial tissues, which are toxic to many pathogens. as these metals can lead to the production of damaging reactive oxygen species (ros), metal hyperaccumulator plants have developed highly effective ros tolerance mechanisms, which might quench ros-based signals. we therefore investigated whether metal accumulation alters defence signalling via ros in this pl ... | 2013 | 23758201 |
| isolation and characterization of dehydration-responsive element-binding factor 2c (msdreb2c) from malus sieversii roem. | dreb2 (dehydration-responsive element-binding factor 2)-type transcription factors play a critical role in the stress-related regulation network in plants. in this study, we isolated and characterized a dreb2 homolog from malus sieversii roem., designated msdreb2c (genbank accession no. jq790526). msdreb2c localized to the nucleus and transactivated reporter genes in yeast strain ygr-2. quantitative real-time pcr analysis demonstrated that msdreb2c was constitutively expressed and significantly ... | 2013 | 23757363 |
| nitrate reductase is required for the transcriptional modulation and bactericidal activity of nitric oxide during the defense response of arabidopsis thaliana against pseudomonas syringae. | nitrate reductase (nr) has emerged as a potential no source in plants. indeed, the arabidopsis thaliana nr double-deficient mutant (nia1 nia2) produces low no and develops abnormal susceptibility to bacterial infection. we have employed quantitative real-time polymerase chain reactions to analyze the effects of no gas on the expression of defense-related genes in wild-type and nia1 nia2 a. thaliana plants that were inoculated with an avirulent strain of pseudomonas syringae pv. tomato. the patho ... | 2013 | 23748675 |
| in planta effector competition assays detect hyaloperonospora arabidopsidis effectors that contribute to virulence and localize to different plant subcellular compartments. | the genome of the pathogenic oomycete hyaloperonospora arabidopsidis is predicted to encode at least 134 high-confidence effectors (harxl) carrying the rxlr motif implicated in their translocation into plant cells. however, only four avirulence genes (atr1, atr13, atr5, and atr39) have been isolated. this indicates that identification of harxl effectors based on avirulence is low throughput. we aimed at rapidly identifying h. arabidopsidis effectors that contribute to virulence by developing met ... | 2013 | 23734779 |
| manipulation of host proteasomes as a virulence mechanism of plant pathogens. | the ubiquitin-26s proteasome degradation system (ups) in plants is involved in the signal transduction of many cellular processes, including host immune responses triggered by pathogen attack. attacking pathogens produce effectors that are translocated into host cells, where they interfere with the host's defense signaling in very specific ways. perhaps not surprising in view of the broad involvement of the host proteasome in plant immunity, certain bacterial effectors exploit or require the hos ... | 2013 | 23725468 |
| pseudomonas syringae pv. tomato dc3000: a model pathogen for probing disease susceptibility and hormone signaling in plants. | since the early 1980s, various strains of the gram-negative bacterial pathogen pseudomonas syringae have been used as models for understanding plant-bacterial interactions. in 1991, a p. syringae pathovar tomato (pst) strain, dc3000, was reported to infect not only its natural host tomato but also arabidopsis in the laboratory, a finding that spurred intensive efforts in the subsequent two decades to characterize the molecular mechanisms by which this strain causes disease in plants. genomic ana ... | 2013 | 23725467 |
| sequence determination and analysis of three plasmids of pseudomonas sp. gle121, a psychrophile isolated from surface ice of ecology glacier (antarctica). | pseudomonas sp. gle121 (a psychrophilic antarctic strain) carries three plasmids: pgle121p1 (6899 bp), pgle121p2 (8330 bp) and pgle121p3 (39,583 bp). plasmids pgle121p1 and pgle121p2 show significant sequence similarity to members of the incp-9 and incp-7 incompatibility groups, respectively, while the largest replicon, pgle121p3, is highly related to plasmid pncppb880-40 of pseudomonas syringae pathovar tomato ncppb880. all three plasmids have a narrow host range, limited to members of the genu ... | 2013 | 23721858 |
| evidence on antimicrobial properties and mode of action of a chitosan obtained from crustacean exoskeletons on pseudomonas syringae pv. tomato dc3000. | pseudomonas syringae pv. tomato dc3000 (pto dc3000) causes bacterial speck of tomato, a widely spread disease that causes significant economical losses worldwide. it is representative of many bacterial plant diseases for which effective controls are still needed. despite the antimicrobial properties of chitosan has been previously described in phytopathogenic fungi, its action on bacteria is still poorly explored. in this work, we report that the chitosan isolated from shrimp exoskeletons (70 kd ... | 2013 | 23703326 |
| structure of 2-haloacid dehalogenase from pseudomonas syringae pv. tomato dc3000. | 2-haloacid dehalogenases (2-hads) catalyse the hydrolytic dehalogenation of 2-haloalkanoic acids, cleaving the carbon-halide bond at the c(α)-atom position and releasing a halogen atom. these enzymes are of interest for their potential use in bioremediation and in the synthesis of industrial chemicals. here, the crystal structure of 2-had from pseudomonas syringae pv. tomato dc3000 (ps-2-had) at 1.98 å resolution solved using the single-wavelength anomalous dispersion method is reported. the ps- ... | 2013 | 23695255 |
| comparative analysis of flagellin glycans among pathovars of phytopathogenic pseudomonas syringae. | flagellin is a principal component of the flagellum filament. previously, we reported that the flagellin of pseudomonas syringae pv. tabaci 6605 (pta6605) was glycosylated by oligosaccharides composed of two or three l-rhamnosyl (l-rha) residues and a terminal 4,6-dideoxy-4-(3-hydroxybutanamide)-2-o-methylglucopyranosyl residue. in this study, we characterized the chemical structure of flagellin glycans in p. syringae pathovars glycinea race 4 (pgl4), phaseolicola 1448a (pph1448a), tomato dc3000 ... | 2013 | 23694710 |
| nonagricultural reservoirs contribute to emergence and evolution of pseudomonas syringae crop pathogens. | while the existence of environmental reservoirs of human pathogens is well established, less is known about the role of nonagricultural environments in emergence, evolution, and spread of crop pathogens. here, we analyzed phylogeny, virulence genes, host range, and aggressiveness of pseudomonas syringae strains closely related to the tomato pathogen p. syringae pv. tomato (pto), including strains isolated from snowpack and streams. the population of pto relatives in nonagricultural environments ... | 2013 | 23692644 |
| the life history of pseudomonas syringae: linking agriculture to earth system processes. | the description of the ecology of pseudomonas syringae is moving away from that of a ubiquitous epiphytic plant pathogen to one of a multifaceted bacterium sans frontières in fresh water and other ecosystems linked to the water cycle. discovery of the aquatic facet of its ecology has led to a vision of its life history that integrates spatial and temporal scales spanning billions of years and traversing catchment basins, continents, and the planet and that confronts the implication of roles that ... | 2013 | 23663005 |
| a tir-nbs protein encoded by arabidopsis chilling sensitive 1 (chs1) limits chloroplast damage and cell death at low temperature. | survival of plants at low temperature depends on mechanisms for limiting physiological damage and maintaining growth. we mapped the chs1-1 (chilling sensitive1-1) mutation in arabidopsis accession columbia to the tir-nbs gene at1g17610. in chs1-1, a single amino acid exchange at the chs1 n-terminus close to the conserved tir domain creates a stable mutant protein that fails to protect leaves against chilling stress. the sequence of another tir-nbs gene (at5g40090) named chl1 (chs1-like 1) is rel ... | 2013 | 23617639 |
| analyses of wrky18 wrky40 plants reveal critical roles of sa/eds1 signaling and indole-glucosinolate biosynthesis for golovinomyces orontii resistance and a loss-of resistance towards pseudomonas syringae pv. tomato avrrps4. | simultaneous mutation of two wrky-type transcription factors, wrky18 and wrky40, renders otherwise susceptible wild-type arabidopsis plants resistant towards the biotrophic powdery mildew fungus golovinomyces orontii. resistance in wrky18 wrky40 double mutant plants is accompanied by massive transcriptional reprogramming, imbalance in salicylic acid (sa) and jasmonic acid (ja) signaling, altered enhanced disease susceptibility1 (eds1) expression, and accumulation of the phytoalexin camalexin. ge ... | 2013 | 23617415 |
| pseudomonas syringae infection assays in arabidopsis. | pseudomonas syringae pv. tomato dc30000 (pst dc3000) infection of arabidopsis thaliana has been widely used to elucidate many of the general principles underlying the plant immune response and bacterial pathogenesis. study of pst dc3000 virulence factors has also proven useful in the discovery and elucidation of fundamental mechanisms in plant biology. in particular, pst dc3000 produces a phytotoxin, coronatine, that is a remarkable molecular mimic of the active form of the plant hormone jasmona ... | 2013 | 23615988 |
| the arabidopsis mediator complex subunits med14/swp and med16/sfr6/ien1 differentially regulate defense gene expression in plant immune responses. | pathogen infection in plants triggers large-scale transcriptional changes, both locally and systemically. emerging evidence suggests that the arabidopsis mediator complex plays a crucial role in these transcriptional changes. mediator is highly conserved in eukaryotes, and its core comprises more than 20 subunits organized into three modules named head, middle and tail. the head and middle modules interact with general transcription factors and rna polymerase ii, whereas the tail module associat ... | 2013 | 23607369 |
| the phytophthora parasitica rxlr effector penetration-specific effector 1 favours arabidopsis thaliana infection by interfering with auxin physiology. | pathogenic oomycetes have evolved rxlr effectors to thwart plant defense mechanisms and invade host tissues. we analysed the function of one of these effectors (penetration-specific effector 1 (pse1)) whose transcript is transiently accumulated during penetration of host roots by the oomycete phytophthora parasitica. expression of pse1 protein in tobacco (nicotiana tabacum and nicotiana benthamiana) leaves and in arabidopsis thaliana plants was used to assess the role of this effector in plant p ... | 2013 | 23594295 |
| new checkpoints in stomatal defense. | recent reports have revealed new guard cell signaling elements that function in stomatal defense in arabidopsis thaliana (arabidopsis). we discuss here the role of oxylipins, salicylic acid (sa), and abscisic acid (aba) in stomatal immunity in response to the bacterial pathogen pseudomonas syringae. | 2013 | 23582764 |
| response of tobacco to the pseudomonas syringae pv. tomato dc3000 is mainly dependent on salicylic acid signaling pathway. | pseudomonas syringae pv. tomato dc3000 (pst dc3000) was the first pathogen to be demonstrated to infect arabidopsis and to cause disease symptoms in the laboratory setting. however, the defense response to pst dc3000 was unclear in tobacco. in this report, the expression profiles of twelve defense response-related genes were analyzed after treatment with salicylic acid (sa), jasmonic acid (ja), and pathogen pst dc3000 by qrt-pcr. according to our results, it could be presented that the genes pri ... | 2013 | 23581479 |
| effects of pesticides on the reduction of plant and human pathogenic bacteria in application water. | overhead spray applications of in-field tomato treatments dissolved in aqueous solutions have specific pest targets (fungal, bacterial, insect, or other). any organism present in the solution or on treated plant surfaces that is not a specific target of the application is unlikely inactivated and can instead be spread through the phyllosphere. in this laboratory study, commercially labeled pesticides (including actigard 50wg, bravo weather stik 6f, cabrio 20eg, kasumin, kocide 3000 46wg, oxidate ... | 2013 | 23575141 |
| zmlea3, a multifunctional group 3 lea protein from maize (zea mays l.), is involved in biotic and abiotic stresses. | late embryogenesis abundant (lea) proteins accumulate to high levels during the late stage of seed maturation and in response to water deficit, and are involved in protecting higher plants from damage caused by environmental stresses, especially drought. in the present study, a novel maize (zea mays l.) group 3 lea gene, zmlea3, was identified and later characterized using transgenic tobacco plants to investigate its functions in abiotic and biotic stresses. transcript accumulation demonstrated ... | 2013 | 23543751 |
| auxin promotes susceptibility to pseudomonas syringae via a mechanism independent of suppression of salicylic acid-mediated defenses. | auxin is a key plant growth regulator that also impacts plant-pathogen interactions. several lines of evidence suggest that the bacterial plant pathogen pseudomonas syringae manipulates auxin physiology in arabidopsis thaliana to promote pathogenesis. pseudomonas syringae strategies to alter host auxin biology include synthesis of the auxin indole-3-acetic acid (iaa) and production of virulence factors that alter auxin responses in host cells. the application of exogenous auxin enhances disease ... | 2013 | 23521356 |
| salmonella colonization activates the plant immune system and benefits from association with plant pathogenic bacteria. | despite increasing incidences of human salmonellosis caused by consumption of contaminated vegetables, relatively little is known about how the plant immune system responds to and may inhibit salmonella colonization. here we show that salmonella typhimurium activates the plant immune system primarily due to its recognition of the flg22 region in salmonella flagellin. several previously identified plant genes that play a role in immunity were found to affect the host response to salmonella. the s ... | 2013 | 23517029 |
| pperf3b, a transcriptional repressor from peach, contributes to disease susceptibility and side branching in ear-dependent and -independent fashions. | peach erf3b is a potent transcriptional repressor for defense-related genes even in the presence of similar levels of transcriptional activators and can interfere with plant development through pathways independent of the ear motif. ethylene response factors (erfs) are a major group of plant transcription factors with either activation or repression capabilities on gene transcription. repressor-type erfs are characterised by an intrinsic motif, namely the erf-associated amphiphilic repression mo ... | 2013 | 23515898 |
| defects in d-rhamnosyl residue biosynthetic genes affect lipopolysaccharide structure, motility, and cell-surface hydrophobicity in pseudomonas syringae pathovar glycinea race 4. | d-rhamnose (d-rha) residue is a major component of lipopolysaccharides (lpss) in strains of the phytopathogen pseudomonas syringae pathovar glycinea. to investigate the effects of a deficiency in gdp-d-rhamnose biosynthetic genes on lps structure and pathogenicity, we generated three mutants defective in d-rha biosynthetic genes, encoding proteins gdp-d-mannose 4,6-dehydratase (gmd), gdp-4-keto-6-deoxy-d-mannose reductase (rmd), and a putative α-d-rhamnosyltransferase (wbpz) in p. syringae pv. g ... | 2013 | 23470736 |
| ketyl radical cyclization of β-disubstituted acrylates: formal syntheses of (+)-secosyrin 1 and longianone and the total synthesis of (+)-4-epi-secosyrin 1. | a novel approach to the synthesis of a series of 1,7-dioxaspirononanes that applies a ketyl radical cyclization strategy is described. radical cyclization of the β-disubstituted acrylate 23, prepared in five steps from (r)-1,2-isopropylideneglycerol, gives both 2,3-syn- and 2,3-anti-furan products. the densely functionalized furan heterocycles are used to complete a concise formal synthesis of secosyrin 1, a metabolite of pseudomonas syringae, and the total synthesis of 4-epi-secosyrin 1. | 2013 | 23452126 |
| deployment of the burkholderia glumae type iii secretion system as an efficient tool for translocating pathogen effectors to monocot cells. | genome sequences of plant fungal pathogens have enabled the identification of effectors that cooperatively modulate the cellular environment for successful fungal growth and suppress host defense. identification and characterization of novel effector proteins are crucial for understanding pathogen virulence and host-plant defense mechanisms. previous reports indicate that the pseudomonas syringae pv. tomato dc3000 type iii secretion system (t3ss) can be used to study how non-bacterial effectors ... | 2013 | 23451734 |
| a substrate-inspired probe monitors translocation, activation, and subcellular targeting of bacterial type iii effector protease avrpphb. | the avrpphb effector of pseudomonas syringae is a papain-like protease that is injected into the host plant cell and cleaves specific kinases to disrupt immune signaling. here, we used the unique substrate specificity of avrpphb to generate a specific activity-based probe. this probe displays various avrpphb isoforms in bacterial extracts, upon secretion and inside the host plant. we show that avrpphb is secreted as a proprotease and that secretion requires the prodomain, but probably does not i ... | 2013 | 23438746 |
| oligonucleotide recombination enabled site-specific mutagenesis in bacteria. | recombineering refers to a strategy for engineering dna sequences using a specialized mode of homologous recombination. this technology can be used for rapidly constructing precise changes in bacterial genome sequences in vivo. oligonucleotide recombination is one type of recombineering that uses ssdna oligonucleotides to direct chromosomal mutations. oligo recombination occurs without addition of any exogenous functions, making this approach potentially useful in many different bacteria. here w ... | 2013 | 23423893 |
| strains of pseudomonas syringae pv. syringae from pea are phylogenetically and pathogenically diverse. | pseudomonas syringae pv. syringae causes extensive yield losses in the pea crop worldwide, although there is little information on its host specialization and its interactions with pea. a collection of 88 putative p. syringae pv. syringae strains (including 39 strains isolated from pea) was characterized by repetitive polymerase chain reaction (rep-pcr), multilocus sequence typing (mlst), and syrb amplification and evaluated for pathogenicity and virulence. rep-pcr data grouped the strains from ... | 2013 | 23384857 |
| the plasma membrane proteome of maize roots grown under low and high iron conditions. | iron (fe) homeostasis is essential for life and has been intensively investigated for dicots, while our knowledge for species in the poaceae is fragmentary. this study presents the first proteome analysis (lc-ms/ms) of plasma membranes isolated from roots of 18-day old maize (zea mays l.). plants were grown under low and high fe conditions in hydroponic culture. in total, 227 proteins were identified in control plants, whereas 204 proteins were identified in fe deficient plants and 251 proteins ... | 2013 | 23353019 |
| sgt1 interacts with the prf resistance protein and is required for prf accumulation and prf-mediated defense signaling. | the highly conserved eukaryotic co-chaperone sgt1 (suppressor of the g2 allele of skp1) is an important signaling component of plant defense responses and positively regulates disease resistance conferred by many resistance (r) proteins. in this study, we investigated the contribution of sgt1 in the prf-mediated defense responses in both nicotiana benthamiana and tomato (solanum lycopersicum). sgt1 was demonstrated to interact with prf in plant cells by co-immunoprecipitation. the requirement of ... | 2013 | 23333384 |
| arabidopsis brassinosteroid-overproducing gulliver3-d/dwarf4-d mutants exhibit altered responses to jasmonic acid and pathogen. | key message : arabidopsis gulliver3 - d/dwarf4 - d displays growth-promoting phenotypes due to activation tagging of a key brassinosteroid biosynthetic gene dwarf4. in gul3-d/dwf4-d , the jasmonate and salicylate signaling pathways were relatively activated and suppressed, respectively. energy allocation between growth and defense is elegantly balanced to achieve optimal development in plants. brassinosteroids (brs), steroidal hormones essential for plant growth, are regulated by other plant hor ... | 2013 | 23297052 |
| gmrin4 protein family members function nonredundantly in soybean race-specific resistance against pseudomonas syringae. | the pseudomonas syringae effector avrb interacts with four related soybean (glycine max) proteins (gmrin4a-d), three (gmrin4b, c, d) of which also interact with the cognate resistance (r) protein, rpg1-b. here, we investigated the specific requirements for the gmrin4 proteins in r-mediated resistance and examined the mechanism of rpg1-b activation. using virus-induced gene silencing, we show that only gmrin4a and b are required for rpg1-b-mediated resistance. in planta binding assays show that g ... | 2013 | 23278373 |
| an acyl-coa-binding protein from grape that is induced through er stress confers morphological changes and disease resistance in arabidopsis. | we here report characterization of a grape (vitis vinifera) acyl-coa-binding protein (vvacbp). expression of vvacbp was detected in grape leaves exposed to tunicamycin-induced endoplasmic reticulum (er) stress as well as cold and heat shock treatments. in tendrils and peduncles, however, high-temperature treatment induced bip (luminal binding protein) expression, a marker of er stress in berry skin, but not vvacbp expression. we hypothesize that vvacbp may be sorted to the periphery of plant cel ... | 2013 | 23261264 |
| effect of fusarium virguliforme phytotoxin on soybean gene expression suggests a role in multidimensional defence. | sudden death syndrome (sds), caused by fusarium virguliforme, is an important yield-limiting disease of soybean. this soil-borne fungus colonizes soybean roots causing root rot, and also releases a phytotoxin that is translocated to leaves causing interveinal chlorosis and necrosis leading to defoliation and early maturation. the objective of our study was to compare gene expression profiles during the early response of soybean leaves exposed to sterile culture filtrates of f. virguliforme in so ... | 2013 | 23240728 |
| in silico prediction of drug targets in phytopathogenic pseudomonas syringae pv. phaseolicola: charting a course for agrigenomics translation research. | pseudomonas syringae pv. phaseolicola is a major plant pathogen causing halo blight disease and has world-wide importance. the emerging post-genomics field of agrigenomics, together with the availability of whole genome sequences of a number of pathogens and host organisms, offer the promise for identification of potential drug targets using sequence comparison approaches. on the other hand, lack of gene expression data for most of the phytopathogenic microbes still remains a formidable barrier. ... | 2012 | 23215808 |
| vascular plant one-zinc-finger protein 1/2 transcription factors regulate abiotic and biotic stress responses in arabidopsis. | plants adapt to abiotic and biotic stresses by activating abscisic acid-mediated (aba) abiotic stress-responsive and salicylic acid-(sa) or jasmonic acid-mediated (ja) biotic stress-responsive pathways, respectively. although the abiotic stress-responsive pathway interacts antagonistically with the biotic stress-responsive pathways, the mechanisms that regulate these pathways remain largely unknown. in this study, we provide insight into the function of vascular plant one-zinc-finger proteins (v ... | 2013 | 23167462 |
| myc2: the master in action. | jasmonates (jas) are plant hormones with essential roles in plant defense and development. the basic-helix-loop-helix (bhlh) transcription factor (tf) myc2 has recently emerged as a master regulator of most aspects of the jasmonate (ja) signaling pathway in arabidopsis. myc2 coordinates ja-mediated defense responses by antagonistically regulating two different branches of the ja signaling pathway that determine resistance to pests and pathogens, respectively. myc2 is required for induced systemi ... | 2013 | 23142764 |
| coronatine, a more powerful elicitor for inducing taxane biosynthesis in taxus media cell cultures than methyl jasmonate. | coronatine is a toxin produced by the pathogen pseudomonas syringae. this compound has received much attention recently for its potential to act as a plant growth regulator and elicitor of plant secondary metabolism. to gain more insight into the mechanism by which elicitors can affect the biosynthesis of paclitaxel (px) and related taxanes, the effect of coronatine (cor) and methyl jasmonate (meja) on taxus media cell cultures has been studied. for this study, a two-stage cell culture was estab ... | 2013 | 23102875 |
| proteomic changes in actinidia chinensis shoot during systemic infection with a pandemic pseudomonas syringae pv. actinidiae strain. | a pandemic, very aggressive population of pseudomonas syringae pv. actinidiae is currently causing severe economic losses to kiwifruit crops worldwide. upon leaf attack, this gram-negative bacterium systemically reaches the plant shoot in a week period. in this study, combined 2-de and nanolc-esi-lit-ms/ms procedures were used to describe major proteomic changes in actinidia chinensis shoot following bacterial inoculation in host leaf. a total of 117 differentially represented protein spots were ... | 2013 | 23099348 |
| [basal bacteriosis of wheat and influence of agrotechnical methods on its spread]. | monitoring of bacterial diseases of wheat was conducted allowing for different doses of mineral fertilizers and crops predecessors. it is shown that symptoms of development of the basic disease of wheat, which is caused by pseudomonas syringae pv. atrofaciens, varied depending on agrotechnical methods, stages of plant growth and environmental factors. introduction of different doses of nitrogen, phosphate and potassium fertilizers, especially high ones, increases the damage of wheat by the agent ... | 2012 | 23088098 |
| atmyb44 regulates wrky70 expression and modulates antagonistic interaction between salicylic acid and jasmonic acid signaling. | the role of atmyb44, an r2r3 myb transcription factor, in signaling mediated by jasmonic acid (ja) and salicylic acid (sa) is examined. atmyb44 is induced by ja through coronatine insensitive 1 (coi1). atmyb44 over-expression down-regulated defense responses against the necrotrophic pathogen alternaria brassicicola, but up-regulated wrky70 and pr genes, leading to enhanced resistance to the biotrophic pathogen pseudomonas syringae pv. tomato dc3000. the knockout mutant atmyb44 shows opposite eff ... | 2013 | 23067202 |
| the tyrosine-sulfated peptide receptors pskr1 and psy1r modify the immunity of arabidopsis to biotrophic and necrotrophic pathogens in an antagonistic manner. | the tyrosine-sulfated peptides pskα and psy1 bind to specific leucine-rich repeat surface receptor kinases and control cell proliferation in plants. in a reverse genetic screen, we identified the phytosulfokine (psk) receptor pskr1 as an important component of plant defense. multiple independent loss-of-function mutants in pskr1 are more resistant to biotrophic bacteria, show enhanced pathogen-associated molecular pattern responses and less lesion formation after infection with the bacterial pat ... | 2013 | 23062058 |
| a salicylic acid-induced rice (oryza sativa l.) transcription factor oswrky77 is involved in disease resistance of arabidopsis thaliana. | plant wrky transcription factors act as either positive or negative regulators of plant basal disease resistance. to comprehensively characterise the complicated functional network, we isolated oswrky77 from rice seedlings treated with salicylic acid. oswrky77 is a typical wrky transcription factor, based on in its protein structure analysis, nuclear localisation of the fused oswrky77-gfp protein and gel electrophoretic mobility shift assay binding, which demonstrated that oswrky77 was able to b ... | 2013 | 23061987 |
| virulence factors are released in association with outer membrane vesicles of pseudomonas syringae pv. tomato t1 during normal growth. | outer membrane vesicles (omvs) are released from pseudomonas syringae pv. tomato t1 (pst t1) during their normal growth. these extracellular compartments are comprised of a complete set of biological macromolecules that includes proteins, lipids, lipopolysaccharides, etc. it is evident from proteomics analyses the omvs of pst t1 contain membrane- and virulence-associated proteins. in addition, omvs of this organism are also associated with phytotoxin, coronatine. therefore, omvs of pst t1 must p ... | 2013 | 23043909 |
| insight into the structure-function relationship of the nonheme iron halogenases involved in the biosynthesis of 4-chlorothreonine --thr3 from streptomyces sp. oh-5093 and syrb2 from pseudomonas syringae pv. syringae b301dr. | molecular cloning of the biosynthetic gene cluster involved in the production of free 4-chlorothreonine in streptomyces sp. oh-5093 showed the presence of six orfs: thr1, thr2, thr3, orf1, orf2 and thr4. according to bioinformatic analysis, thr1, thr2, thr3 and thr4 encode a free-standing adenylation domain, a carrier protein, an fe(ii) nonheme α-ketoglutarate-dependent halogenase and a thioesterase, respectively, indicating the role of these genes in the activation and halogenation of threonine ... | 2012 | 23025743 |
| pseudomonas syringae self-protection from tabtoxinine-β-lactam by ligase tblf and acetylase ttr. | plant pathogenic pseudomonas syringae produce the hydroxy-β-lactam antimetabolite tabtoxinine-β-lactam (tβl) as a time-dependent inactivating glutamine analogue of plant glutamine synthetases. the producing pseudomonads use multiple modes of self-protection, two of which are characterized in this study. the first is the dipeptide ligase tblf which converts tabtoxinine-β-lactam to the tβl-thr dipeptide known as tabtoxin. the dipeptide is not recognized by glutamine synthetase. this represents a t ... | 2012 | 22994681 |
| the salicylic acid receptor npr3 is a negative regulator of the transcriptional defense response during early flower development in arabidopsis. | arabidopsis non-expressor of pr1 (npr1) is a transcription co-activator that plays a central role in regulating the transcriptional response to plant pathogens. the npr family consists of npr1 and five npr1-like genes. the npr1 paralog npr3 has recently been shown to function as a receptor of the plant hormone salicylic acid and to mediate proteosomal degradation of npr1. the function of npr3 protein during early flower development was revealed through a detailed molecular-genetic analysis inclu ... | 2013 | 22986789 |
| alternative oxidase impacts the plant response to biotic stress by influencing the mitochondrial generation of reactive oxygen species. | previously, we showed that inoculation of tobacco with pseudomonas syringae incompatible pv. maculicola results in a rapid and persistent burst of superoxide (o(2) (-) ) from mitochondria, no change in amount of mitochondrial alternative oxidase (aox) and induction of the hypersensitive response (hr). however, inoculation with incompatible pv. phaseolicola resulted in increased aox, no o(2) (-) burst and no hr. here, we show that in transgenic plants unable to induce aox in response to pv. phase ... | 2013 | 22978428 |
| expression of pseudomonas syringae type iii effectors in yeast under stress conditions reveals that hopx1 attenuates activation of the high osmolarity glycerol map kinase pathway. | the gram-negative bacterium pseudomonas syringae pv. tomato (pst) is the causal agent of speck disease in tomato. pst pathogenicity depends on a type iii secretion system that delivers effector proteins into host cells, where they promote disease by manipulating processes to the advantage of the pathogen. previous studies identified seven pst effectors that inhibit growth when expressed in yeast under normal growth conditions, suggesting that they interfere with cellular processes conserved in y ... | 2012 | 22977090 |
| activation of r-mediated innate immunity and disease susceptibility is affected by mutations in a cytosolic o-acetylserine (thiol) lyase in arabidopsis. | o-acetylserine (thiol) lyases (oastls) are evolutionarily conserved proteins among many prokaryotes and eukaryotes that perform sulfur acquisition and synthesis of cysteine. a mutation in the cytosolic oastl-a1 protein onset of leaf death3 (old3) was previously shown to reduce the oastl activity of the old3-1 protein in vitro and cause auto-necrosis in specific arabidopsis accessions. here we investigated why a mutation in this protein causes auto-necrosis in some but not other accessions. the a ... | 2013 | 22974487 |
| constitutive activation of brassinosteroid signaling in the arabidopsis elongated-d/bak1 mutant. | defects in brassinosteroid (br) biosynthetic or signaling genes result in dwarfed plants, whereas overexpression of these genes increases overall stature. an arabidopsis elongated-d (elg-d) mutant shares phenotypic similarities with br overexpression lines, suggesting its implication in br pathways. here, we determine how elg-d affects br signaling. since elg-d rescued dwarfism in bri1-5 plants, a br receptor mutant, but not in br-insensitive bin2/dwf12-1d plants, elg-d appears to act between br ... | 2012 | 22961663 |
| carbon source and cell density-dependent regulation of type iii secretion system gene expression in pseudomonas syringae pathovar tomato dc3000. | pseudomonas syringae utilizes a type iii secretion system (t3ss) encoded by the hrp/hrc genes to translocate virulence proteins called effectors into plant cells. to ensure that the t3ss functions at appropriate times during infection, hrp/hrc and effector gene expression is modulated by environmental conditions and a complex network of transcription factors. the sigma factor hrpl activates hrp/hrc and effector genes, while σ(54) and enhancer binding proteins hrpr and hrps regulate hrpl. to bett ... | 2015 | 22944041 |
| changes in cytosolic atp levels and intracellular morphology during bacteria-induced hypersensitive cell death as revealed by real-time fluorescence microscopy imaging. | hypersensitive cell death is known to involve dynamic remodeling of intracellular structures that uses energy released during atp hydrolysis. however, the relationship between intracellular structural changes and atp levels during hypersensitive cell death remains unclear. here, to visualize atp dynamics directly in real time in individual living plant cells, we applied a genetically encoded förster resonance energy transfer (fret)-based fluorescent atp indicator, ateam1.03-nd/na, for plant cell ... | 2012 | 22942251 |
| oxidative stress acts on special membrane proteins to reduce the viability of pseudomonas syringae pv tomato. | reactive oxygen species (ros) play a vital role in reducing the viability of invading pathogens during plant-pathogen interactions. to understand how oxidative stress caused by ros reduces cell viability, it is important to identify the proteins affected by ros. in the present study, we investigated the changes in the expression of proteins from the outer and inner membrane fractions in pseudomonas syringae pv tomato dc3000 under oxidative stress through membrane subproteomics. a total number of ... | 2012 | 22928751 |
| the pepper mlo gene, camlo2, is involved in the susceptibility cell-death response and bacterial and oomycete proliferation. | loss-of-function alleles of the mildew resistance locus o (mlo) gene provide broad-spectrum powdery mildew disease resistance. here, we identified a pepper (capsicum annuum) mlo gene (camlo2) that is transcriptionally induced by xanthomonas campestris pv. vesicatoria (xcv) infection. topology and subcellular localization analyses reveal that camlo2 is a plasma membrane-anchored and amphiphilic ca²⁺-dependent calmodulin-binding protein. camlo2 expression is up-regulated by xcv and salicylic acid, ... | 2012 | 22913752 |
| simultaneous degradation of organophosphate and organochlorine pesticides by sphingobium japonicum ut26 with surface-displayed organophosphorus hydrolase. | a genetically engineered microorganism (gem) capable of simultaneously degrading organophosphate and organochlorine pesticides was constructed for the first time by display of organophosphorus hydrolase (oph) on the cell surface of a hexachlorocyclohexane (hch)-degrading sphingobium japonicum ut26. the gem could potentially be used for removing the two classes of pesticides that may be present in mixtures at contaminated sites. a surface anchor system derived from the truncated ice nucleation pr ... | 2013 | 22910813 |
| phylogenetic relationships among global populations of pseudomonas syringae pv. actinidiae. | abstract pseudomonas syringae pv. actinidiae, the causal agent of canker in kiwifruit (actinidia spp.) vines, was first detected in japan in 1984, followed by detections in korea and italy in the early 1990s. isolates causing more severe disease symptoms have recently been detected in several countries with a wide global distribution, including italy, new zealand, and china. in order to characterize p. syringae pv. actinidiae populations globally, a representative set of 40 isolates from new zea ... | 2012 | 22877312 |
| arabidopsis clade i tga transcription factors regulate plant defenses in an npr1-independent fashion. | transcriptional reprogramming during induction of salicylic acid (sa)-mediated defenses is regulated primarily by npr1 (nonexpressor of pathogenesis-related genes 1), likely through interactions with tga bzip transcription factors. to ascertain the contributions of clade i tga factors (tga1 and tga4) to defense responses, a tga1-1 tga4-1 double mutant was constructed and challenged with pseudomonas syringae and hyaloperonospora arabidopsidis. although the mutant displayed enhanced susceptibility ... | 2012 | 22876961 |
| regulation of biosynthesis of syringolin a, a pseudomonas syringae virulence factor targeting the host proteasome. | many strains of the phytopathogenic bacterium pseudomonas syringae pv. syringae synthesize the virulence factor syringolin a, which irreversibly inactivates the eukaryotic proteasome. syringolin a, a peptide derivative, is synthesized by a mixed nonribosomal peptide/polyketide synthetase encoded by five clustered genes, syla to syle. biosynthesis of syringolin a, previously shown to be dependent on the gacs/gaca two-component system, occurs in planta and in vitro but only under still culture con ... | 2012 | 22852810 |
| lack of the golgi phosphate transporter pht4;6 causes strong developmental defects, constitutively activated disease resistance mechanisms and altered intracellular phosphate compartmentation in arabidopsis. | the golgi-located phosphate exporter pht4;6 has been described as involved in salt tolerance but further analysis on the physiological impact of pht4;6 remained elusive. here we show that pht4;6-gfp is targeted to the trans-golgi compartment and that loss of function of this carrier protein has a dramatic impact on plant growth and development. knockout mutants of pht4;6 exhibit a dwarf phenotype that is complemented by the homologous gene from rice (oryza sativa). interestingly, pht4;6 mutants ... | 2012 | 22788523 |
| bacterial canker on kiwifruit in italy: anatomical changes in the wood and in the primary infection sites. | the bacterial canker of kiwifruit caused by pseudomonas syringae pv. actinidiae is a severe threat to kiwifruit production worldwide. many aspects of p. syringae pv. actinidiae biology and epidemiology still require in-depth investigation. the infection by and spread of p. syringae pv. actinidiae in xylem and phloem was investigated by carrying out artificial inoculation experiments with histological and dendrochronological analyses of naturally diseased plants in italy. we found that the bacter ... | 2012 | 22713076 |
| transgenic expression of tobacco mosaic virus capsid and movement proteins modulate plant basal defense and biotic stress responses in nicotiana tabacum. | plant viruses cause metabolic and physiological changes associated with symptomatic disease phenotypes. symptoms involve direct and indirect effects, which result in disruption of host physiology. we used transgenic tobacco expressing a variant of tobacco mosaic virus (tmv) coat protein (cp(t42w)) or movement protein (mp), and a hybrid line (mp×cp(t42w)) that coexpresses both proteins, to study the plant response to individual viral proteins. findings employing microarray analysis of mp×cp(t42w) ... | 2012 | 22712510 |
| homologous rxlr effectors from hyaloperonospora arabidopsidis and phytophthora sojae suppress immunity in distantly related plants. | diverse pathogens secrete effector proteins into plant cells to manipulate host cellular processes. oomycete pathogens contain large complements of predicted effector genes defined by an rxlr host cell entry motif. the genome of hyaloperonospora arabidopsidis (hpa, downy mildew of arabidopsis) contains at least 134 candidate rxlr effector genes. only a small subset of these genes is conserved in related oomycetes from the phytophthora genus. here, we describe a comparative functional characteriz ... | 2012 | 22709376 |
| thiamine induced resistance to plasmopara viticola in grapevine and elicited host-defense responses, including hr like-cell death. | recently, thiamine (vitaminb1) has been shown to induce resistance against pseudomonas syringae in arabidopsis plants through priming of defense responses. in this paper, we have demonstrated the efficiency of thiamine to induce resistance against downy mildew caused by the oomycete plasmopara viticola in a susceptible vitis vinifera cultivar "chardonnay" under glasshouse controlled conditions by providing a dual mode of action involving direct antifungal activity and elicitation of host-defense ... | 2012 | 22698755 |
| overexpression of xanthomonas campestris pv. vesicatoria effector avrbst in arabidopsis triggers plant cell death, disease and defense responses. | recognition of bacterial effector proteins by plant cells is crucial for plant disease and defense response signaling. the xanthomonas campestris pv. vesicatoria (xcv) type iii effector protein, avrbst, is secreted into plant cells from xcv strain bv5-4a. here, we demonstrate that dexamethasone (dex): avrbst overexpression triggers cell death signaling in healthy transgenic arabidopsis plants. avrbst overexpression in arabidopsis also reduced susceptibility to infection with the obligate biotrop ... | 2012 | 22678032 |
| stochastic modeling of pseudomonas syringae growth in the phyllosphere. | pseudomonas syringae is a gram-negative bacterium which lives on leaf surfaces. its growth has been described using epifluorescence microscopy and image analysis; it was found to be growing in aggregates of a wide range of sizes. we develop a stochastic model to describe aggregate distribution and determine the mechanisms generating experimental observations. we found that a logistic birth-death model with migration (time-homogeneous markov process) provides the best description of the observed ... | 2012 | 22659411 |
| multiple lessons from the multiple functions of a regulator of type iii secretion system assembly in the plant pathogen pseudomonas syringae. | the assembly of type iii secretion systems (t3sss), which inject bacterial effector proteins into the cytosol of animal and plant hosts, is a highly regulated process. animal pathogens use a length-control protein to produce t3ss needles of fixed length and then a second regulator, such as yopn in yersinia spp, to mediate host contact-dependent effector delivery. for pseudomonas syringae and other plant pathogens, regulation of the assembly process differs because the t3ss pilus must grow throug ... | 2012 | 22646515 |
| the pseudomonas syringae hrpj protein controls the secretion of type iii translocator proteins and has a virulence role inside plant cells. | the bacterial plant pathogen pseudomonas syringae injects effector proteins into plant cells via a type iii secretion system (t3ss), which is required for pathogenesis. the protein hrpj is secreted by p. syringae and is required for a fully functional t3ss. a hrpj mutant is non-pathogenic and cannot inject effectors into plant cells or secrete the harpin hrpz1. here we show that the hrpj mutant also cannot secrete the harpins hrpw1 and hopak1 or the translocator hrpk1, suggesting that these prot ... | 2012 | 22607547 |
| plant erd2-like proteins function as endoplasmic reticulum luminal protein receptors and participate in programmed cell death during innate immunity. | the hypersensitive response (hr), a form of programmed cell death (pcd), is a tightly regulated innate immune response in plants that is hypothesized to restrict pathogen growth and disease development. although considerable efforts have been made to understand hr pcd, it remains unknown whether the retrograde pathway from the golgi to the endoplasmic reticulum (er) is involved. here we provide direct genetic evidence that two nicotiana benthamiana homologs, erd2a and erd2b, function as er lumin ... | 2012 | 22595145 |
| genome-wide analysis of wrky transcription factors in solanum lycopersicum. | the wrky transcription factors have been implicated in multiple biological processes in plants, especially in regulating defense against biotic and abiotic stresses. however, little information is available about the wrkys in tomato (solanum lycopersicum). the recent release of the whole-genome sequence of tomato allowed us to perform a genome-wide investigation for tomato wrky proteins, and to compare these positively identified proteins with their orthologs in model plants, such as arabidopsis ... | 2012 | 22570076 |
| cml9, an arabidopsis calmodulin-like protein, contributes to plant innate immunity through a flagellin-dependent signalling pathway. | many stimuli such as hormones and elicitors induce changes in intracellular calcium levels to integrate information and activate appropriate responses. the ca(2+) signals are perceived by various ca(2+) sensors, and calmodulin (cam) is one of the best characterized in eukaryotes. calmodulin-like (cml) proteins extend the ca(2+) toolkit in plants; they share sequence similarity with the ubiquitous and highly conserved cam but their roles at physiological and molecular levels are largely unknown. ... | 2012 | 22563930 |
| the mediator subunit sfr6/med16 controls defence gene expression mediated by salicylic acid and jasmonate responsive pathways. | • arabidopsis sensitive to freezing6 (sfr6) controls cold- and drought-inducible gene expression and freezing- and osmotic-stress tolerance. its identification as a component of the mediator transcriptional co-activator complex led us to address its involvement in other transcriptional responses. • gene expression responses to pseudomonas syringae, ultraviolet-c (uv-c) irradiation, salicylic acid (sa) and jasmonic acid (ja) were investigated in three sfr6 mutant alleles by quantitative real-time ... | 2012 | 22494141 |
| the arabidopsis ubiquitin ligases atl31 and atl6 control the defense response as well as the carbon/nitrogen response. | in higher plants, the metabolism of carbon (c) and nitrogen nutrients (n) is mutually regulated and referred to as the c and n balance (c/n). plants are thus able to optimize their growth depending on their cellular c/n status. arabidopsis atl31 and atl6 encode a ring-type ubiquitin ligases which play a critical role in the c/n status response (sato et al. in plant j 60:852-864, 2009). since many atl members are involved in the plant defense response, the present study evaluated whether the c/n ... | 2012 | 22481162 |
| calmodulin-binding protein cbp60g is a positive regulator of both disease resistance and drought tolerance in arabidopsis. | calmodulin-binding proteins (cbps) have been known to be involved in both biotic and abiotic stress responses. recently, two closely related cbps, arabidopsis sar deficient 1 and cbp60g, were found to belong to a new family of transcription factors that regulate salicylic acid (sa) biosynthesis triggered by microbe-associated molecular patterns. in this study, we found that overexpression of cbp60g in arabidopsis caused elevated sa accumulation, increased expression of the defense genes, and enh ... | 2012 | 22466450 |
| plant programmed cell death caused by an autoactive form of prf is suppressed by co-expression of the prf lrr domain. | in tomato, the nbarc-lrr resistance (r) protein prf acts in concert with the pto or fen kinase to determine immunity against pseudomonas syringae pv. tomato (pst). prf-mediated defense signaling is initiated by the recognition of two sequence-unrelated pst-secreted effector proteins, avrpto and avrptob, by tomato pto or fen. prf detects these interactions and activates signaling leading to host defense responses including localized programmed cell death (pcd) that is associated with the arrest o ... | 2012 | 22451646 |
| probing dna-lipid membrane interactions with a lipopeptide nanopore. | association of dna molecules with lipid bilayer membranes is of considerable interest for a large variety of applications in biotechnology. here we introduce syringomycin e (sre), a small pore-forming lipopeptide produced by the bacterium pseudomonas syringae, as a facile sensor for the detection of dna interactions with lipid membranes. sre forms highly reproducible pores in cellular and artificial membranes. the pore structure involves bilayer lipids, which have a pronounced influence on open ... | 2012 | 22424398 |
| disruption of pamp-induced map kinase cascade by a pseudomonas syringae effector activates plant immunity mediated by the nb-lrr protein summ2. | pathogen-associated molecular pattern (pamp)-triggered immunity (pti) serves as a primary plant defense response against microbial pathogens, with mekk1, mkk1/mkk2, and mpk4 functioning as a map kinase cascade downstream of pamp receptors. plant resistance (r) proteins sense specific pathogen effectors to initiate a second defense mechanism, termed effector-triggered immunity (eti). in a screen for suppressors of the mkk1 mkk2 autoimmune phenotype, we identify the nucleotide-binding leucine-rich ... | 2012 | 22423965 |
| differential expression of membrane proteins helps antarctic pseudomonas syringae to acclimatize upon temperature variations. | antarctic bacteria are adapted to the extremely low temperature. the transcriptional and translational machineries of these bacteria are adapted to the sub-zero degrees of temperature. studies directed towards identifying the changes in the protein profiles during changes in the growth temperatures of an antarctic bacterium pseudomonas syringae lz4w may help in understanding the molecular basis of cold adaptation. in this study, subcellular fractionation methods of proteins were used for the enr ... | 2012 | 22418587 |
| complex formation between heme oxygenase and phytochrome during biosynthesis in pseudomonas syringae pv. tomato. | the plant pathogen pseudomonas syringae pv. tomato carries two genes encoding bacterial phytochromes. sequence motifs identify both proteins (pstbphp1 and pstbphp2, respectively) as biliverdin ixα (bv)-binding phytochromes. pstbphp1 is arranged in an operon with a heme oxygenase (pstbpho)-encoding gene (pstbpho), whereas pstbphp2 is flanked downstream by a gene encoding a chey-type response regulator. expression of the heme oxygenase pstbpho yielded a green protein (λ(max) = 650 nm), indicative ... | 2012 | 22415794 |
| the molecular basis of host specialization in bean pathovars of pseudomonas syringae. | biotrophic phytopathogens are typically limited to their adapted host range. in recent decades, investigations have teased apart the general molecular basis of intraspecific variation for innate immunity of plants, typically involving receptor proteins that enable perception of pathogen-associated molecular patterns or avirulence elicitors from the pathogen as triggers for defense induction. however, general consensus concerning evolutionary and molecular factors that alter host range across clo ... | 2012 | 22414441 |
| the awr gene family encodes a novel class of ralstonia solanacearum type iii effectors displaying virulence and avirulence activities. | we present here the characterization of a new gene family, awr, found in all sequenced ralstonia solanacearum strains and in other bacterial pathogens. we demonstrate that the five paralogues in strain gmi1000 encode type iii-secreted effectors and that deletion of all awr genes severely impairs its capacity to multiply in natural host plants. complementation studies show that the awr (alanine-tryptophan-arginine tryad) effectors display some functional redundancy, although awr2 is the major con ... | 2012 | 22414437 |
| hda19 is required for the repression of salicylic acid biosynthesis and salicylic acid-mediated defense responses in arabidopsis. | to cope with a lifetime of exposure to a variety of pathogens, plants have developed exquisite and refined defense mechanisms that vary depending on the type of attacking pathogen. defense-associated transcriptional reprogramming is a central part of plant defense mechanisms. chromatin modification has recently been shown to be another layer of regulation for plant defense mechanisms. here, we show that the rpd3/hda1-class histone deacetylase hda19 is involved in the repression of salicylic acid ... | 2012 | 22381007 |
| arabidopsis plants having defects in nonsense-mediated mrna decay factors upf1, upf2, and upf3 show photoperiod-dependent phenotypes in development and stress responses. | nonsense-mediated mrna decay (nmd) is an important mrna quality surveillance pathway in all eukaryotes that eliminates aberrant mrnas derived from various sources. three nmd factor proteins, upf1, upf2, and upf3 are required for the nmd process and were found to be also involved in certain stress responses in mammalian and yeast cells. using arabidopsis thaliana mutants of upf1 and upf3 and upf2-silenced lines (irupf2), we examined the involvement of upf1, upf2, and upf3 in development and in re ... | 2012 | 22353561 |
| type iv pilin is glycosylated in pseudomonas syringae pv. tabaci 6605 and is required for surface motility and virulence. | type iv pilin (pila) is a major constituent of pilus and is required for bacterial biofilm formation, surface motility and virulence. it is known that mature pila is produced by cleavage of the short leader sequence of the pilin precursor, followed by methylation of n-terminal phenylalanine. the molecular mass of the pila mature protein from the tobacco bacterial pathogen pseudomonas syringae pv. tabaci 6605 (pta 6605) has been predicted to be 12 329 da from its deduced amino acid sequence. prev ... | 2012 | 22353307 |
| pseudomonas syringae pv. actinidiae: a re-emerging, multi-faceted, pandemic pathogen. | pseudomonas syringae pv. actinidiae is the causal agent of bacterial canker of green-fleshed kiwifruit (actinidia deliciosa) and yellow-fleshed kiwifruit (a. chinensis). a recent, sudden, re-emerging wave of this disease has occurred, almost contemporaneously, in all of the main areas of kiwifruit production in the world, suggesting that it can be considered as a pandemic disease. recent in-depth genetic studies performed on p. syringae pv. actinidiae strains have revealed that this pathovar is ... | 2012 | 22353258 |
| the peptide growth factor, phytosulfokine, attenuates pattern-triggered immunity. | pattern-triggered immunity (pti) is triggered by recognition of elicitors called microbe-associated molecular patterns (mamps). although immune responses may provide good protection of plants from pathogen attack, excessive immune responses have negative impacts on plant growth and development. thus, a good balance between positive and negative effects on the immune signaling network is important for plant fitness. however, little information is known about the molecular mechanisms that are invo ... | 2012 | 22353039 |
| pseudomonas syringae type iii effector repertoires: last words in endless arguments. | many plant pathogens subvert host immunity by injecting compositionally diverse but functionally similar repertoires of cytoplasmic effector proteins. the bacterial pathogen pseudomonas syringae is a model for exploring the functional structure of such repertoires. the pangenome of p. syringae encodes 57 families of effectors injected by the type iii secretion system. distribution of effector genes among phylogenetically diverse strains reveals a small set of core effectors targeting antimicrobi ... | 2012 | 22341410 |
| volatile dose and exposure time impact perception in neighboring plants. | volatiles emitted from stressed plants can induce resistance in healthy neighbors. it remains unknown, however, how plants perceive volatiles and convert them into internal signals. we exposed lima bean (phaseolus lunatus l.) to different concentrations of either of two volatiles, nonanal and methyl salicylate (mesa), over 6 or 24 h. plant resistance to the bacterial pathogen, pseudomonas syringae, was increased significantly after exposure to a headspace with two concentrations of nonanal for 6 ... | 2012 | 22327276 |
| arabidopsis wrky46 coordinates with wrky70 and wrky53 in basal resistance against pathogen pseudomonas syringae. | the wrky transcription factors are involved in plant resistance against both biotrophic and necrotrophic pathogens. arabidopsis wrky46 is specifically induced by salicylic acid (sa) and biotrophic pathogen pseudomonas syringae infection. to determine its possible roles in plant defense and elucidate potential functional redundancy with structurally related wrky70 and wrky53, we examined loss-of-function t-dna insertion single, double and triple mutants, as well as gain-of-function transgenic wrk ... | 2012 | 22325892 |
| ornithine-delta-aminotransferase and proline dehydrogenase genes play a role in non-host disease resistance by regulating pyrroline-5-carboxylate metabolism-induced hypersensitive response. | non-host disease resistance involves the production of hypersensitive response (hr), a programmed cell death (pcd) that occurs at the site of pathogen infection. plant mitochondrial reactive oxygen species (ros) production and red-ox changes play a major role in regulating such cell death. proline catabolism reactions, especially pyrroline-5-carboxylate (p5c) accumulation, are known to produce ros and contribute to cell death. here we studied important genes related to proline synthesis and cata ... | 2012 | 22321246 |
| detection, characterization and quantification of salicylic acid conjugates in plant extracts by esi tandem mass spectrometric techniques. | an approach for the detection and characterization of sa derivatives in plant samples is presented based on liquid chromatography coupled to electrospray ionization (esi) tandem mass spectrometric techniques. precursor ion scan methods using an esi triple quadrupole spectrometer for samples from plants challenged with the virulent pseudomonas syringae pv tomato dc3000 allowed us to detect two potential sa derivatives. the criterion used to consider a potential sa derivative is based on the detec ... | 2012 | 22285411 |
| the role of a periplasmic gluconolactonase (ppgl)-like protein in pseudomonas syringae pv. syringae b728a. | in pseudomonas syringae pv. syringae b728a, the psyr_1712 locus id encodes a putative protein with a signal peptide and a cog2706 domain of the type present in 3-carboxy-cis,cis-muconate lactonizing enzymes. an amino acid sequence alignment of the p. aeruginosa ppgl with other genome sequenced fluorescent pseudomonads such as p. syringae psyr_1712 showed that they have the same enzymatic active site residue comprising one histidine, one glutamic acid and two arginines. based on the similarity of ... | 2011 | 25187129 |
| organization of an arabidopsis thaliana gene cluster on chromosome 4 including the rps2 gene, in the brassica nigra genome. | genetic and physical maps, consisting of a large number of dna markers for arabidopsis thaliana chromosomes, represent excellent tools to determine the organization of related genomes such as those of brassica. in this paper we report the chromosomal localization and physical analysis by pulsed-field gel electrophoresis (pfge) of a well-defined gene complex of a. thaliana in the brassica nigra genome (b genome n=8). this complex is approximately 30 kb in length in a. thaliana and contains a clus ... | 1998 | 24710886 |
| syntheses and potato tuber-inducing activity of coronafacic acid analogues. | coronafacic acid (1) is an acid component of coronatine, and has been isolated from several pathovars of pseudomonas syringae. syntheses of c6-non- and c6-alkyl-substituted analogues of 1 were accomplished via intramolecular 1,6-conjugate addition as the key step. among them, 1 and four c6-alkyl-substituted analogues exhibited potato tuber-inducing activity, but the c6-non-substituted analogue did not. it was revealed that a certain length of the c6-alkyl group was necessary to exhibit activity. | 1998 | 27392555 |
| specificity of induced resistance in the tomato, lycopersicon esculentum. | specificity in the induced responses of tomato foliage to arthropod herbivores was investigated. we distinguished between two aspects of specificity: specificity of effect (the range of organisms affected by a given induced response), and specificity of elicitation (ability of the plant to generate distinct chemical responses to different damage types). specificity of effect was investigated by examining the effect of restricted feeding by helicoverpa zea on the resistance of tomato plants to an ... | 1997 | 28307296 |
| pto3 and pto4: novel genes from lycopersicon hirsutum var. glabratum that confer resistance to pseudomonas syringae pv tomato. | accessions of wild lycopersicon germplasm were screened for resistance to pseudomonas syringae pv tomato (p.s. tomato). resistance to both race-0 and race-1 strains of p.s. tomato was identified in l. pimpinellifolium, l. peruvianum and l. hirsutum var. glabratum. resistance to race-0 derived from l. hirsutum var. glabratum (pto3) appeared to be inherited independently of pto1 and pto2. filial and backcross generations derived from interspecific crosses between l. esculentum and l. hirsutum var. ... | 1994 | 24178099 |
| the expression of cecropin peptide in transgenic tobacco does not confer resistance to pseudomonas syringae pv tabaci. | we used in vitro growth inhibition assays to demonstrate that synthetic cecropin protein has potent activity against a range of plant pathogenic bacteria. we then prepared transgenic tobacco plants which express cecropin mrna and protein. we have used pseudomonas syringae pv tabaci infection of these transgenic tobacco as a model system to evaluate whether the plants which express cecropin protein also have increased tolerance to infection. we found no dramatic difference in disease response bet ... | 1994 | 24193769 |
| new disease resistance genes in soybean against pseudomonas syringae pv glycinea: evidence that one of them interacts with a bacterial elicitor. | soybean [glycine max (l.) merr.] cultivars flambeau and merit differed in their resistance to pseudomonas syringae pv glycinea (psg) race 4, carrying each of four different avirulence (avr) genes cloned from psg or the related bacterium, pseudomonas syringae pv tomato. segregation data for f2 and f3 progeny of flambeau x merit crosses indicated that single dominant and nonallelic genes account for resistance to psg race 4, carrying avirulence genes avra, avrb, avrc, or avrd. segregants were also ... | 1991 | 24221170 |