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regulation of cell wall-bound invertase in pepper leaves by xanthomonas campestris pv. vesicatoria type three effectors.xanthomonas campestris pv. vesicatoria (xcv) possess a type 3 secretion system (t3ss) to deliver effector proteins into its solanaceous host plants. these proteins are involved in suppression of plant defense and in reprogramming of plant metabolism to favour bacterial propagation. there is increasing evidence that hexoses contribute to defense responses. they act as substrates for metabolic processes and as metabolic semaphores to regulate gene expression. especially an increase in the apoplast ...201223272161
cloning of a conserved receptor-like protein kinase gene and its use as a functional marker for homoeologous group-2 chromosomes of the triticeae species.receptor-like kinases (rlks) play broad biological roles in plants. we report on a conserved receptor-like protein kinase (rpk) gene from wheat and other triticeae species. the tarpk1 was isolated from the triticum aestivum cv. prins - triticum timopheevii introgression line igvi-465 carrying the powdery mildew resistance gene pm6. the tarpk1 was mapped to homoeologous chromosomes 2a (tarpk1-2a), 2d (tarpk1-2d) and the pm6-carrier chromosome 2g (tarpk1-2g) of igvi-465. under the tested condition ...201223272050
parallel loss-of-function at the rpm1 bacterial resistance locus in arabidopsis thaliana.dimorphism at the resistance to pseudomonas syringae pv. maculicola 1 (rpm1) locus is well documented in natural populations of arabidopsis thaliana and has been portrayed as a long-term balanced polymorphism. the haplotype from resistant plants contains the rpm1 gene, which enables these plants to recognize at least two structurally unrelated bacterial effector proteins (avrb and avrrpm1) from bacterial crop pathogens. a complete deletion of the rpm1 coding sequence has been interpreted as a si ...201223272006
the role of canonical and noncanonical pre-mrna splicing in plant stress responses.plants are sessile organisms capable of adapting to various environmental constraints, such as high or low temperatures, drought, soil salinity, or pathogen attack. to survive the unfavorable conditions, plants actively employ pre-mrna splicing as a mechanism to regulate expression of stress-responsive genes and reprogram intracellular regulatory networks. there is a growing evidence that various stresses strongly affect the frequency and diversity of alternative splicing events in the stress-re ...201223509698
the role of canonical and noncanonical pre-mrna splicing in plant stress responses.plants are sessile organisms capable of adapting to various environmental constraints, such as high or low temperatures, drought, soil salinity, or pathogen attack. to survive the unfavorable conditions, plants actively employ pre-mrna splicing as a mechanism to regulate expression of stress-responsive genes and reprogram intracellular regulatory networks. there is a growing evidence that various stresses strongly affect the frequency and diversity of alternative splicing events in the stress-re ...201223509698
a role in immunity for arabidopsis cysteine protease rd21, the ortholog of the tomato immune protease c14.secreted papain-like cys proteases are important players in plant immunity. we previously reported that the c14 protease of tomato is targeted by cystatin-like epic proteins that are secreted by the oomycete pathogen phytophthora infestans (pinf) during infection. c14 has been under diversifying selection in wild potato species coevolving with pinf and reduced c14 levels result in enhanced susceptibility for pinf. here, we investigated the role c14-epic-like interactions in the natural pathosyst ...201222238602
slya regulates t3ss genes in parallel with the t3ss master regulator hrpl in dickeya dadantii 3937.the hrp (hypersensitive response and pathogenicity) genes of dickeya dadantii 3937 encode a type iii secretion system (t3ss) which is essential for its full virulence. previous studies of the t3ss regulation in d. dadantii 3937 revealed that the expression of the hrp genes is regulated by a master regulator hrpl through the hrpx-hrpy-hrps-hrpl and gacs-gaca-rsmb-rsma pathways. in this work, we identified a novel regulator of the slya/marr family, slya, which regulates hrp genes of the hrpl regul ...201222267675
arabidopsis histidine kinase 5 regulates salt sensitivity and resistance against bacterial and fungal infection.• the ability of plants to adapt to multiple stresses imposed by the natural environment requires cross-talk and fine-tuning of stress signalling pathways. the hybrid histidine kinase arabidopsis histidine kinase 5 (ahk5) is known to mediate stomatal responses to exogenous and endogenous signals in arabidopsis thaliana. the purpose of this study was to determine whether the function of ahk5 in stress signalling extends beyond stomatal responses. • plant growth responses to abiotic stresses, tiss ...201222256998
environmental factors affecting the expression of pilab as well as the proteome and transcriptome of the grass endophyte azoarcus sp. strain bh72.bacterial communication is involved in regulation of cellular mechanisms such as metabolic processes, microbe-host interactions or biofilm formation. in the nitrogen-fixing model endophyte of grasses azoarcus sp. strain bh72, known cell-cell signaling systems have not been identified; however, the pila gene encoding the structural protein of type iv pili that are essential for plant colonization appears to be regulated in a population density-dependent manner.201222276194
stenotrophomonas maltophilia: an emerging global opportunistic pathogen.summary: stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen. the increasing incidence of nosocomial and community-acquired s. maltophilia infections is of particular concern for immunocompromised individuals, as this bacterial pathogen is associated with a significant fatality/case ratio. s. maltophilia is an environmental bacterium found in aqueous habitats, including plant rhizospheres, animals, foods, and water sources. infections of s. maltophilia c ...201222232370
variation in local carrying capacity and the individual fate of bacterial colonizers in the phyllosphere.using a phyllosphere model system, we demonstrated that the term 'carrying capacity', as it is commonly used in microbial ecology, needs to be understood as the sum of many 'local carrying capacities' in order to better explain and predict the course and outcome of bacterial colonization of an environment. using a green fluorescent protein-based bioreporter system for the quantification of reproductive success (rs) in individual erwinia herbicola cells, we were able to reconstruct the contributi ...201222258099
broad-spectrum acquired resistance in barley induced by the pseudomonas pathosystem shares transcriptional components with arabidopsis sar.inducible resistance responses play a central role in the defence of plants against pathogen attack. acquired resistance (ar) is induced alongside defence towards primary attack, providing broad-spectrum protection against subsequent pathogen challenge. the localisation and molecular basis of ar in cereals is poorly understood, in contrast with the well-characterised systemic acquired resistance (sar) response in arabidopsis. here, we use pseudomonas syringae as a biological inducer of ar in bar ...201222250583
hopas1 recognition significantly contributes to arabidopsis nonhost resistance to pseudomonas syringae pathogens.• plant immunity is activated by sensing either conserved microbial signatures, called pathogen/microbe-associated molecular patterns (p/mamps), or specific effectors secreted by pathogens. however, it is not known why most microbes are nonpathogenic in most plant species. • nonhost resistance (nhr) consists of multiple layers of innate immunity and protects plants from the vast majority of potentially pathogenic microbes. effector-triggered immunity (eti) has been implicated in race-specific di ...201222053875
Two small RNAs, CrcY and CrcZ, act in concert to sequester the Crc global regulator in Pseudomonas putida, modulating catabolite repression.The Crc protein is a translational repressor that recognizes a specific target at some mRNAs, controlling catabolite repression and co-ordinating carbon metabolism in pseudomonads. In Pseudomonas aeruginosa, the levels of free Crc protein are controlled by CrcZ, a sRNA that sequesters Crc, acting as an antagonist. We show that, in Pseudomonas putida, the levels of free Crc are controlled by CrcZ and by a novel 368 nt sRNA named CrcY. CrcZ and CrcY, which contain six potential targets for Crc, we ...201222053874
Conserved Structural Mechanisms for Autoinhibition in IpaH Ubiquitin Ligases.The IpaH family of novel E3 ligase (NEL) enzymes occur in a variety of pathogenic and commensal bacteria that interact with eukaryotic hosts. We demonstrate that the leucine-rich repeat (LRR) substrate recognition domains of different IpaH enzymes autoinhibit the enzymatic activity of the adjacent catalytic novel E3 ligase domain by two distinct but conserved structural mechanisms. Autoinhibition is required for the in vivo biological activity of two IpaH enzymes in a eukaryotic model system. Au ...201222065585
Conserved Structural Mechanisms for Autoinhibition in IpaH Ubiquitin Ligases.The IpaH family of novel E3 ligase (NEL) enzymes occur in a variety of pathogenic and commensal bacteria that interact with eukaryotic hosts. We demonstrate that the leucine-rich repeat (LRR) substrate recognition domains of different IpaH enzymes autoinhibit the enzymatic activity of the adjacent catalytic novel E3 ligase domain by two distinct but conserved structural mechanisms. Autoinhibition is required for the in vivo biological activity of two IpaH enzymes in a eukaryotic model system. Au ...201222065585
Proteomic analysis of colony morphology variants of Burkholderia pseudomallei defines a role for the arginine deiminase system in bacterial survival.Colony morphology variation of Burkholderia pseudomallei is a notable feature of a proportion of primary clinical cultures from patients with melioidosis. Here, we examined the hypothesis that colony morphology switching results in phenotypic changes associated with enhanced survival under adverse conditions. We generated isogenic colony morphology types II and III from B. pseudomallei strain 153 type I, and compared their protein expression profiles using 2D gel electrophoresis. Numerous protei ...201222062159
Ethylene-Responsive Element-Binding Factor 5, ERF5, Is Involved in Chitin-Induced Innate Immunity Response.Our recent work demonstrated that chitin treatment modulated the expression of 118 transcription factor (TF) genes in Arabidopsis. To investigate the potential roles of these TF in chitin signaling and plant defense, we initiated an interaction study among these TF proteins, as well as two chitin-activated mitogen-activated protein kinases (MPK3 and MPK6), using a yeast two-hybrid system. This study revealed interactions among the following proteins: three ethylene-responsive element-binding fac ...201221936663
contribution of siderophore systems to growth and urinary tract colonization of asymptomatic bacteriuria escherichia coli.the molecular mechanisms that define asymptomatic bacteriuria (abu) escherichia coli colonization of the human urinary tract remain to be properly elucidated. here, we utilize abu e. coli strain 83972 as a model to dissect the contribution of siderophores to iron acquisition, growth, fitness, and colonization of the urinary tract. we show that e. coli 83972 produces enterobactin, salmochelin, aerobactin, and yersiniabactin and examine the role of these systems using mutants defective in sideroph ...201221930757
mRNA context dependent regulation of cytotoxic necrotizing factor 1 translation by GidA, a tRNA modification enzyme in Escherichia coli.Cytotoxic necrotizing factor 1 (CNF1), the paradigm of Rho GTPase activating bacterial toxins has been shown to promote E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, but its synthesis and secretion is unclear. In this study, we performed mini Tn5 mutagenesis screen to identify genetic requirements for CNF1 production and secretion. Transposon mutagenesis screen of meningitis-causing E. coli K1 strain RS218 revealed that CNF1 pr ...201222020226
mRNA context dependent regulation of cytotoxic necrotizing factor 1 translation by GidA, a tRNA modification enzyme in Escherichia coli.Cytotoxic necrotizing factor 1 (CNF1), the paradigm of Rho GTPase activating bacterial toxins has been shown to promote E. coli invasion of human brain microvascular endothelial cells (HBMEC), which constitute the blood-brain barrier, but its synthesis and secretion is unclear. In this study, we performed mini Tn5 mutagenesis screen to identify genetic requirements for CNF1 production and secretion. Transposon mutagenesis screen of meningitis-causing E. coli K1 strain RS218 revealed that CNF1 pr ...201222020226
The Arabidopsis short-chain dehydrogenase/reductase 3, an ABSCISIC ACID DEFICIENT 2 homolog, is involved in plant defense responses but not in ABA biosynthesis.ABSCISIC ACID DEFICIENT2 (ABA2) encodes a short-chain dehydrogenase/reductase1 (SDR1) that catalyzes the multi-step conversion of xanthoxin to abscisic aldehyde during abscisic acid (ABA) biosynthesis in Arabidopsis thaliana. In this study, AtSDR2 and AtSDR3, the two closest homologs to AtABA2, were investigated for their potential role in ABA biosynthesis. AtSDR2 showed undetectable transcription in plants grown under normal conditions or under stress. AtSDR3 and AtABA2 have different spatial a ...201222153241
high-throughput analysis of growth differences among phage strains.although methods such as spectrophotometry are useful for identifying growth differences among bacterial strains, it is currently difficult to similarly determine whether bacteriophage strains differ in growth using high throughput methods. here we use automated spectrophotometry to develop an in vitro method for indirectly distinguishing fitness (growth) differences among virus strains, based on direct measures of their infected bacterial hosts. we used computer simulations of a mathematical mo ...201222101310
a tomato lysm receptor-like kinase promotes immunity and its kinase activity is inhibited by avrptob.resistance in tomato (solanum lycopersicum) to infection by pseudomonas syringae involves both detection of pathogen-associated molecular patterns (pamps) and recognition by the host pto kinase of pathogen effector avrptob which is translocated into the host cell and interferes with pamp-triggered immunity (pti). the n-terminal portion of avrptob is sufficient for its virulence activity and for recognition by pto. an amino acid substitution in avrptob, f173a, abolishes these activities. to inves ...201221880077
a tomato lysm receptor-like kinase promotes immunity and its kinase activity is inhibited by avrptob.resistance in tomato (solanum lycopersicum) to infection by pseudomonas syringae involves both detection of pathogen-associated molecular patterns (pamps) and recognition by the host pto kinase of pathogen effector avrptob which is translocated into the host cell and interferes with pamp-triggered immunity (pti). the n-terminal portion of avrptob is sufficient for its virulence activity and for recognition by pto. an amino acid substitution in avrptob, f173a, abolishes these activities. to inves ...201221880077
HrpZ harpins from different Pseudomonas syringae pathovars differ in molecular interactions and in induction of anion channel responses in Arabidopsis thaliana suspension cells.HrpZ, a type three secretion system helper protein from the plant-pathogen Pseudomonas syringae, can be recognized by many plants as a defence elicitor. Responses of Arabidopsis thaliana suspension cells to different HrpZ variants were studied by electrophysiological methods and cell death assay. Purified HrpZ originating from a compatible pathogen P. syringae pv. tomato DC3000 (HrpZ(Pto)) and incompatible P. syringae pv. phaseolicola (HrpZ(Pph)) both promoted Arabidopsis cell death. As an early ...201222153254
Syringolin B-inspired proteasome inhibitor analogue TIR-203 exhibits enhanced biological activity in multiple myeloma and neuroblastoma.Context: The bacterium Pseudomonas syringae pv. syringae (Pss) is a pathogen of many plant species and causes, for example, brown spot disease in bean plants (Phaseolus vulgaris). Pss excretes the syringolins, natural product molecules that act as a virulence factors and inhibit the proteasome of the host plants. Objective: Proteasome inhibitors belong to an important class of anticancer agents and bortezomib (Velcade(®)) has been Food and Drug Administration-approved for the treatment of mult ...201222196580
genome sequence of azospirillum brasilense cbg497 and comparative analyses of azospirillum core and accessory genomes provide insight into niche adaptation.bacteria of the genus azospirillum colonize roots of important cereals and grasses, and promote plant growth by several mechanisms, notably phytohormone synthesis. the genomes of several azospirillum strains belonging to different species, isolated from various host plants and locations, were recently sequenced and published. in this study, an additional genome of an a. brasilense strain, isolated from maize grown on an alkaline soil in the northeast of mexico, strain cbg497, was obtained. compa ...201224705077
plant growth-promoting bacteria: mechanisms and applications.the worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. it is therefore essential that agricultural productivity be significantly increased within the next few decades. to this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. this includes both the increasing use of transgenic plants and plant ...201224278762
cellular function and molecular structure of ecto-nucleotidases.ecto-nucleotidases play a pivotal role in purinergic signal transmission. they hydrolyze extracellular nucleotides and thus can control their availability at purinergic p2 receptors. they generate extracellular nucleosides for cellular reuptake and salvage via nucleoside transporters of the plasma membrane. the extracellular adenosine formed acts as an agonist of purinergic p1 receptors. they also can produce and hydrolyze extracellular inorganic pyrophosphate that is of major relevance in the c ...201222555564
characterization of nitric oxide-inducing lipid a derived from mesorhizobium loti lipopolysaccharide.mesorhizobium loti is a member of the rhizobia and forms nitrogen-fixing symbioses with several lotus species. recently, it was reported that m. loti bacterial cells and their lipopolysaccharide (lps) preparations transiently induced nitric oxide (no) production in the roots of l. japonicus. we subsequently found that polysaccharides and the lipid a moiety were responsible for this no induction. in this study, we elucidated the chemical structure of m. loti lipid a and characterized its no-induc ...201223059724
the effect of iron limitation on the transcriptome and proteome of pseudomonas fluorescens pf-5.one of the most important micronutrients for bacterial growth is iron, whose bioavailability in soil is limited. consequently, rhizospheric bacteria such as pseudomonas fluorescens employ a range of mechanisms to acquire or compete for iron. we investigated the transcriptomic and proteomic effects of iron limitation on p. fluorescens pf-5 by employing microarray and itraq techniques, respectively. analysis of this data revealed that genes encoding functions related to iron homeostasis, including ...201222723948
iodide oxidation by a novel multicopper oxidase from the alphaproteobacterium strain q-1.alphaproteobacterium strain q-1 is able to oxidize iodide (i(-)) to molecular iodine (i(2)) by an oxidase-like enzyme. one of the two isoforms of the iodide-oxidizing enzyme (ioe-ii) produced by this strain was excised from a native polyacrylamide gel, eluted, and purified. ioe-ii appeared as a single band (51 kda) and showed significant in-gel iodide-oxidizing activity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis without heat treatment. however, at least two bands with much high ...201222447601
comparative transcriptional analysis of homologous pathogenic and non-pathogenic lawsonia intracellularis isolates in infected porcine cells.lawsonia intracellularis is the causative agent of proliferative enteropathy. this disease affects various animal species, including nonhuman primates, has been endemic in pigs, and is an emerging concern in horses. non-pathogenic variants obtained through multiple passages in vitro do not induce disease, but bacterial isolates at low passage induce clinical and pathological changes. we hypothesize that genes differentially expressed between pathogenic (passage 10) and non-pathogenic (passage 60 ...201223056413
reproductive clonality of pathogens: a perspective on pathogenic viruses, bacteria, fungi, and parasitic protozoa.we propose that clonal evolution in micropathogens be defined as restrained recombination on an evolutionary scale, with genetic exchange scarce enough to not break the prevalent pattern of clonal population structure, a definition already widely used for all kinds of pathogens, although not clearly formulated by many scientists and rejected by others. the two main manifestations of clonal evolution are strong linkage disequilibrium (ld) and widespread genetic clustering ("near-clading"). we hyp ...201222949662
bactquant: an enhanced broad-coverage bacterial quantitative real-time pcr assay.bacterial load quantification is a critical component of bacterial community analysis, but a culture-independent method capable of detecting and quantifying diverse bacteria is needed. based on our analysis of a diverse collection of 16 s rrna gene sequences, we designed a broad-coverage quantitative real-time pcr (qpcr) assay--bactquant--for quantifying 16 s rrna gene copy number and estimating bacterial load. we further utilized in silico evaluation to complement laboratory-based qpcr characte ...201222510143
different biosynthetic pathways to fosfomycin in pseudomonas syringae and streptomyces species.fosfomycin is a wide-spectrum antibiotic that is used clinically to treat acute cystitis in the united states. the compound is produced by several strains of streptomycetes and pseudomonads. we sequenced the biosynthetic gene cluster responsible for fosfomycin production in pseudomonas syringae pb-5123. surprisingly, the biosynthetic pathway in this organism is very different from that in streptomyces fradiae and streptomyces wedmorensis. the pathways share the first and last steps, involving co ...201222615277
comparative analysis of two phenotypically-similar but genomically-distinct burkholderia cenocepacia-specific bacteriophages.genomic analysis of bacteriophages infecting the burkholderia cepacia complex (bcc) is an important preliminary step in the development of a phage therapy protocol for these opportunistic pathogens. the objective of this study was to characterize kl1 (vb_bces_kl1) and ah2 (vb_bces_ah2), two novel burkholderia cenocepacia-specific siphoviruses isolated from environmental samples.201222676492
polymorphic toxin systems: comprehensive characterization of trafficking modes, processing, mechanisms of action, immunity and ecology using comparative genomics.proteinaceous toxins are observed across all levels of inter-organismal and intra-genomic conflicts. these include recently discovered prokaryotic polymorphic toxin systems implicated in intra-specific conflicts. they are characterized by a remarkable diversity of c-terminal toxin domains generated by recombination with standalone toxin-coding cassettes. prior analysis revealed a striking diversity of nuclease and deaminase domains among the toxin modules. we systematically investigated polymorp ...201222731697
fluoride resistance and transport by riboswitch-controlled clc antiporters.a subclass of bacterial clc anion-transporting proteins, phylogenetically distant from long-studied clcs, was recently shown to be specifically up-regulated by f(-). we establish here that a set of randomly selected representatives from this "clc(f)" clade protect escherichia coli from f(-) toxicity, and that the purified proteins catalyze transport of f(-) in liposomes. sequence alignments and membrane transport experiments using (19)f nmr, osmotic response assays, and planar lipid bilayer reco ...201222949689
integrating conjugative elements as vectors of antibiotic, mercury, and quaternary ammonium compound resistance in marine aquaculture environments.the presence of sxt/r391-related integrating conjugative elements (ices) in bacterial strains isolated from fish obtained from marine aquaculture environments in 2001 to 2010 in the northwestern iberian peninsula was studied. ices were detected in 12 strains taxonomically related to vibrio scophthalmi (3 strains), vibrio splendidus (5 strains), vibrio alginolyticus (1 strain), shewanella haliotis (1 strain), and enterovibrio nigricans (2 strains), broadening the known host range able to harbor s ...201222314526
bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins.the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ...201222192777
bioinformatic characterization of the 4-toluene sulfonate uptake permease (tsup) family of transmembrane proteins.the ubiquitous sequence diverse 4-toluene sulfonate uptake permease (tsup) family contains few characterized members and is believed to catalyze the transport of several sulfur-based compounds. prokaryotic members of the tsup family outnumber the eukaryotic members substantially, and in prokaryotes, but not eukaryotes, extensive lateral gene transfer occurred during family evolution. despite unequal representation, homologues from the three taxonomic domains of life share well-conserved motifs. ...201222192777
Transcript and metabolite analysis of the Trichoderma-induced systemic resistance response to Pseudomonas syringae in Arabidopsis thaliana.In the present study we have assessed, by transcriptional and metabolic profiling, the systemic defence response of Arabidopsis thaliana plants to the leaf pathogen Pseudomonas syringae pv. tomato DC3000 (Pst) induced by the beneficial fungus Trichoderma asperelloides T203. Expression analysis (qPCR) of a set of 137 Arabidopsis genes related to Pst defence responses showed that T203 root colonization is not associated with major detectable transcriptomic changes in leaves. However, plants challe ...201221852347
E622, a miniature, virulence-associated mobile element.Miniature inverted terminal repeat elements (MITEs) are nonautonomous mobile elements that have a significant impact on bacterial evolution. Here we characterize E622, a 611-bp virulence-associated MITE from Pseudomonas syringae, which contains no coding region but has almost perfect 168-bp inverted repeats. Using an antibiotic coupling assay, we show that E622 is transposable and can mobilize an antibiotic resistance gene contained between its borders. Its predicted parent element, designated T ...201222081398
cj1386 is an ankyrin-containing protein involved in heme trafficking to catalase in campylobacter jejuni.campylobacter jejuni, a microaerophilic bacterium, is the most frequent cause of human bacterial gastroenteritis. c. jejuni is exposed to harmful reactive oxygen species (ros) produced during its own normal metabolic processes and during infection from the host immune system and from host intestinal microbiota. these ros will damage dna and proteins and cause peroxidation of lipids. consequently, identifying ros defense mechanisms is important for understanding how campylobacter survives this en ...201222081390
duplex quantitative real-time pcr assay for the detection and discrimination of the eggs of toxocara canis and toxocara cati (nematoda, ascaridoidea) in soil and fecal samples.toxocarosis is a zoonotic disease caused by toxocara canis (t. canis) and/or toxocara cati (t. cati), two worldwide distributed roundworms which are parasites of canids and felids, respectively. infections of humans occur through ingestion of embryonated eggs of t. canis or t. cati, when playing with soils contaminated with dogs or cats feces. accordingly, the assessment of potential contamination of these areas with these roundworms eggs is paramount.201223216873
signal molecules mediate the impact of the earthworm aporrectodea caliginosa on growth, development and defence of the plant arabidopsis thaliana.earthworms have generally a positive impact on plant growth, which is often attributed to a trophic mechanism: namely, earthworms increase the release of mineral nutrients from soil litter and organic matter. an alternative hypothesis has been proposed since the discovery of a signal molecule (indole acetic acid) in earthworm faeces. in this study, we used methodologies developed in plant science to gain information on ecological mechanisms involved in plant-earthworm interaction, by looking at ...201223226498
ethylene in mutualistic symbioses.ethylene (et) is a gaseous phytohormone that participates in various plant physiological processes and essentially contributes to plant immunity. et conducts its functions by regulating the expression of et-responsive genes or in crosstalk with other hormones. several recent studies have shown the significance of et in the establishment and development of plant-microbe interactions. therefore, it is not surprising that pathogens and mutualistic symbionts target et synthesis or signaling to colon ...201223072986
induced resistance by a long-chain bacterial volatile: elicitation of plant systemic defense by a c13 volatile produced by paenibacillus polymyxa.some strains of plant growth-promoting rhizobacteria (pgpr) elicit induced systemic resistance (isr) by emission of volatile organic compounds (vocs) including short chain alcohols, acetoin, and 2,3-butanediol. the objective of this study was to evaluate whether species-specific vocs from pgpr strain paenibacillus polymyxa e681 can promote growth and induce resistance in arabidopsis.201223209558
small rnas and their role in biofilm formation.the formation of biofilms is initiated by bacteria transitioning from the planktonic to the surface-associated mode of growth. several regulatory systems have been described to govern the initiation and subsequent formation of biofilms. recent evidence suggests that regulatory networks governing the decision of bacteria whether to attach and form biofilms or remain as planktonic cells are further subject to regulation by small non-coding rnas (srnas). this is accomplished by srnas fine-tuning re ...201223178000
small rnas and their role in biofilm formation.the formation of biofilms is initiated by bacteria transitioning from the planktonic to the surface-associated mode of growth. several regulatory systems have been described to govern the initiation and subsequent formation of biofilms. recent evidence suggests that regulatory networks governing the decision of bacteria whether to attach and form biofilms or remain as planktonic cells are further subject to regulation by small non-coding rnas (srnas). this is accomplished by srnas fine-tuning re ...201223178000
assessment of the relevance of the antibiotic 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine from pantoea agglomerans biological control strains against bacterial plant pathogens.the epiphyte pantoea agglomerans 48b/90 (pa48b) is a promising biocontrol strain against economically important bacterial pathogens such as erwinia amylovora. strain pa48b produces the broad-spectrum antibiotic 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine (apv) in a temperature-dependent manner. an apv-negative mutant still suppressed the e. amylovora population and fire blight disease symptoms in apple blossom experiments under greenhouse conditions, but was inferior to the pa48b wild ...201223233458
synthase-dependent exopolysaccharide secretion in gram-negative bacteria.the biosynthesis and export of bacterial cell-surface polysaccharides is known to occur through several distinct mechanisms. recent advances in the biochemistry and structural biology of several proteins in synthase-dependent polysaccharide secretion systems have identified key conserved components of this pathway in gram-negative bacteria. these components include an inner-membrane-embedded polysaccharide synthase, a periplasmic tetratricopeptide repeat (tpr)-containing scaffold protein, and an ...201223117123
synthase-dependent exopolysaccharide secretion in gram-negative bacteria.the biosynthesis and export of bacterial cell-surface polysaccharides is known to occur through several distinct mechanisms. recent advances in the biochemistry and structural biology of several proteins in synthase-dependent polysaccharide secretion systems have identified key conserved components of this pathway in gram-negative bacteria. these components include an inner-membrane-embedded polysaccharide synthase, a periplasmic tetratricopeptide repeat (tpr)-containing scaffold protein, and an ...201223117123
metabolic and transcriptomic changes induced in arabidopsis by the rhizobacterium pseudomonas fluorescens ss101.systemic resistance induced in plants by nonpathogenic rhizobacteria is typically effective against multiple pathogens. here, we show that root-colonizing pseudomonas fluorescens strain ss101 (pf.ss101) enhanced resistance in arabidopsis (arabidopsis thaliana) against several bacterial pathogens, including pseudomonas syringae pv tomato (pst) and the insect pest spodoptera exigua. transcriptomic analysis and bioassays with specific arabidopsis mutants revealed that, unlike many other rhizobacter ...201223073694
characterization of bacteria associated with pinewood nematode bursaphelenchus xylophilus.pine wilt disease (pwd) is a complex disease integrating three major agents: the pathogenic agent, the pinewood nematode bursaphelenchus xylophilus; the insect-vector monochamus spp.; and the host pine tree, pinus sp. since the early 80's, the notion that another pathogenic agent, namely bacteria, may play a role in pwd has been gaining traction, however the role of bacteria in pwd is still unknown. the present work supports the possibility that some b. xylophilus-associated bacteria may play a ...201223091599
methylobacterium-induced endophyte community changes correspond with protection of plants against pathogen attack.plant inoculation with endophytic bacteria that normally live inside the plant without harming the host is a highly promising approach for biological disease control. the mechanism of resistance induction by beneficial bacteria is poorly understood, because pathways are only partly known and systemic responses are typically not seen. the innate endophytic community structures change in response to external factors such as inoculation, and bacterial endophytes can exhibit direct or indirect antag ...201223056459
fatty acid biosynthesis in pseudomonas aeruginosa is initiated by the faby class of β-ketoacyl acyl carrier protein synthases.the prototypical type ii fatty acid synthesis (fas) pathway in bacteria utilizes two distinct classes of β-ketoacyl synthase (kas) domains to assemble long-chain fatty acids, the kasiii domain for initiation and the kasi/ii domain for elongation. the central role of fas in bacterial viability and virulence has stimulated significant effort toward developing kas inhibitors, particularly against the kasiii domain of the β-acetoacetyl-acyl carrier protein (acp) synthase fabh. herein, we show that t ...201222753059
virulence of the pseudomonas fluorescens clinical strain mfn1032 towards dictyostelium discoideum and macrophages in relation with type iii secretion system.pseudomonas fluorescens biovar i mfn1032 is a clinical isolate able to grow at 37°c. this strain displays secretion-mediated hemolytic activity involving phospholipase c and cyclolipopeptides, and a cell-associated hemolytic activity distinct from the secreted hemolytic activity. cell-associated hemolysis is independent of biosurfactant production and remains in a gaca mutant. disruption of the hrpu-like operon (the basal part of type iii secretion system from rhizospheric strains) suppresses th ...201223020706
new secreted toxins and immunity proteins encoded within the type vi secretion system gene cluster of serratia marcescens.protein secretion systems are critical to bacterial virulence and interactions with other organisms. the type vi secretion system (t6ss) is found in many bacterial species and is used to target either eukaryotic cells or competitor bacteria. however, t6ss-secreted proteins have proven surprisingly elusive. here, we identified two secreted substrates of the antibacterial t6ss from the opportunistic human pathogen, serratia marcescens. ssp1 and ssp2, both encoded within the t6ss gene cluster, were ...201222957938
the crystal structure of the lipid ii-degrading bacteriocin syringacin m suggests unexpected evolutionary relationships between colicin m-like bacteriocins.colicin-like bacteriocins show potential as next generation antibiotics with clinical and agricultural applications. key to these potential applications is their high potency and species specificity that enables a single pathogenic species to be targeted with minimal disturbance of the wider microbial community. here we present the structure and function of the colicin m-like bacteriocin, syringacin m from pseudomonas syringae pv. tomato dc3000. syringacin m kills susceptible cells through a hig ...201222995910
distinct regions of the pseudomonas syringae coiled-coil effector avrrps4 are required for activation of immunity.gram-negative phytopathogenic bacteria translocate effector proteins into plant cells to subvert host defenses. these effectors can be recognized by plant nucleotide-binding-leucine-rich repeat immune receptors, triggering defense responses that restrict pathogen growth. avrrps4, an effector protein from pseudomonas syringae pv. pisi, triggers rps4-dependent immunity in resistant accessions of arabidopsis. to better understand the molecular basis of avrrps4-triggered immunity, we determined the ...201222988101
microbe-associated molecular patterns-triggered root responses mediate beneficial rhizobacterial recruitment in arabidopsis.this study demonstrated that foliar infection by pseudomonas syringae pv tomato dc3000 induced malic acid (ma) transporter (aluminum-activated malate transporter1 [almt1]) expression leading to increased ma titers in the rhizosphere of arabidopsis (arabidopsis thaliana). ma secretion in the rhizosphere increased beneficial rhizobacteria bacillus subtilis fb17 (hereafter fb17) titers causing an induced systemic resistance response in plants against p. syringae pv tomato dc3000. having shown that ...201222972705
functional and structural characterization of paem, a colicin m-like bacteriocin produced by pseudomonas aeruginosa.colicin m (colm) is the only enzymatic colicin reported to date that inhibits cell wall peptidoglycan biosynthesis. it catalyzes the specific degradation of the lipid intermediates involved in this pathway, thereby provoking lysis of susceptible escherichia coli cells. a gene encoding a homologue of colm was detected within the exou-containing genomic island a carried by certain pathogenic pseudomonas aeruginosa strains. this bacteriocin (pyocin) that we have named paem was crystallized, and its ...201222977250
molecular characterization of an ice nucleation protein variant (inaq) from pseudomonas syringae and the analysis of its transmembrane transport activity in escherichia coli.the ice nucleation protein (inp) of pseudomonas syringae has gained scientific interest not only because of its pathogenicity of foliar necroses but also for its wide range of potential applications, such as in snow making, frozen food preparation, and surface-display system development. however, studies on the transport activity of inp remain lacking. in the present study, a newly identified inp-gene variant, inaq, from a p. syringae mb03 strain was cloned. its structural domains, signal sequen ...201222991498
multiple transcription-activating sequences regulate the rsmz regulatory small rna of pseudomonas brassicacearum.the muts-rpos region is known to be a highly polymorphic segment of the chromosome owing to horizontal gene transfer and evolutionary processes. in pseudomonas, muts-fdxa-rsmz-rpos organization is highly conserved, as well as the promoter region of the rsmz small rna (srna)-encoding gene. one exception to this conservation is in pseudomonas brassicacearum, where a 308-nucleotide (nt) sequence, predicted to form a hairpin structure in single-stranded dna (ssdna), is inserted between the rpos and ...201222773788
membrane vesicle formation as a multiple-stress response mechanism enhances pseudomonas putida dot-t1e cell surface hydrophobicity and biofilm formation.among the adaptive responses of bacteria to rapid changes in environmental conditions, those of the cell envelope are known to be the most crucial. therefore, several mechanisms with which bacteria change their cell surface and membranes in the presence of different environmental stresses have been elucidated. among these mechanisms, the release of outer membrane vesicles (mv) in gram-negative bacteria has attracted particular research interest because of its involvement in pathogenic processes, ...201222752175
pseudomonas aeruginosa possesses two putative type i signal peptidases, lepb and pa1303, each with distinct roles in physiology and virulence.type i signal peptidases (spases) cleave signal peptides from proteins during translocation across biological membranes and hence play a vital role in cellular physiology. spase activity is also of fundamental importance to the pathogenesis of infection for many bacteria, including pseudomonas aeruginosa, which utilizes a variety of secreted virulence factors, such as proteases and toxins. p. aeruginosa possesses two noncontiguous spase homologues, lepb (pa0768) and pa1303, which share 43% amino ...201222730125
biocontrol of tomato wilt disease by bacillus subtilis isolates from natural environments depends on conserved genes mediating biofilm formation.bacillus subtilis and other bacilli have long been used as biological control agents against plant bacterial diseases but the mechanisms by which the bacteria confer protection are not well understood. our goal in this study was to isolate strains of b. subtilis that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. we screened a total of 60 isolates collected from various locations across china ...201222934631
biocontrol of tomato wilt disease by bacillus subtilis isolates from natural environments depends on conserved genes mediating biofilm formation.bacillus subtilis and other bacilli have long been used as biological control agents against plant bacterial diseases but the mechanisms by which the bacteria confer protection are not well understood. our goal in this study was to isolate strains of b. subtilis that exhibit high levels of biocontrol efficacy from natural environments and to investigate the mechanisms by which these strains confer plant protection. we screened a total of 60 isolates collected from various locations across china ...201222934631
iron-regulated metabolites produced by pseudomonas fluorescens wcs374r are not required for eliciting induced systemic resistance against pseudomonas syringae pv. tomato in arabidopsis.the plant growth-promoting rhizobacterium pseudomonas fluorescens wcs374r produces several iron-regulated metabolites, including the fluorescent siderophore pseudobactin (psb374), salicylic acid (sa), and pseudomonine (psm), a siderophore that contains a sa moiety. after purification of psb374 from culture supernatant of wcs374r, its structure was determined following isoelectrofocusing and tandem mass spectrometry, and found to be identical to the fluorescent siderophore produced by p. fluoresc ...201223170230
advances in bacteriophage-mediated control of plant pathogens.there is continuing pressure to maximise food production given a growing global human population. bacterial pathogens that infect important agricultural plants (phytopathogens) can reduce plant growth and the subsequent crop yield. currently, phytopathogens are controlled through management programmes, which can include the application of antibiotics and copper sprays. however, the emergence of resistant bacteria and the desire to reduce usage of toxic products that accumulate in the environment ...201222934116
avrrpm1 missense mutations weakly activate rps2-mediated immune response in arabidopsis thaliana.plants recognize microbes via specific pattern recognition receptors that are activated by microbe-associated molecular patterns (mamps), resulting in mamp-triggered immunity (mti). successful pathogens bypass mti in genetically diverse hosts via deployment of effectors (virulence factors) that inhibit mti responses, leading to pathogen proliferation. plant pathogenic bacteria like pseudomonas syringae utilize a type iii secretion system to deliver effectors into cells. these effectors can contr ...201222880057
hr4 gene is induced in the arabidopsis-trichoderma atroviride beneficial interaction.plants are constantly exposed to microbes, for this reason they have evolved sophisticated strategies to perceive and identify biotic interactions. thus, plants have large collections of so-called resistance (r) proteins that recognize specific microbe factors as signals of invasion. one of these proteins is codified by the arabidopsis thaliana hr4 gene in the col-0 ecotype that is homologous to rpw8 genes present in the ms-0 ecotype. in this study, we investigated the expression patterns of the ...201222942755
extensive remodeling of the pseudomonas syringae pv. avellanae type iii secretome associated with two independent host shifts onto hazelnut.hazelnut (corylus avellana) decline disease in greece and italy is caused by the convergent evolution of two distantly related lineages of pseudomonas syringae pv. avellanae (pav). we sequenced the genomes of three pav isolates to determine if their convergent virulence phenotype had a common genetic basis due to either genetic exchange between lineages or parallel evolution.201222800299
requirement of siderophore biosynthesis for plant colonization by salmonella enterica.contaminated fresh produce has become the number one vector of nontyphoidal salmonellosis to humans. however, salmonella enterica genes essential for the life cycle of the organism outside the mammalian host are for the most part unknown. screening deletion mutants led to the discovery that an aroa mutant had a significant root colonization defect due to a failure to replicate. aroa is part of the chorismic acid biosynthesis pathway, a central metabolic node involved in aromatic amino acid and s ...201222522683
integration of bioinformatics and synthetic promoters leads to the discovery of novel elicitor-responsive cis-regulatory sequences in arabidopsis.a combination of bioinformatic tools, high-throughput gene expression profiles, and the use of synthetic promoters is a powerful approach to discover and evaluate novel cis-sequences in response to specific stimuli. with arabidopsis (arabidopsis thaliana) microarray data annotated to the pathoplant database, 732 different queries with a focus on fungal and oomycete pathogens were performed, leading to 510 up-regulated gene groups. using the binding site estimation suite of tools, best, 407 conse ...201222744985
plant-growth promoting effect of newly isolated rhizobacteria varies between two arabidopsis ecotypes.various rhizobacteria are known for their beneficial effects on plants, i. e. promotion of growth and induction of systemic resistance against pathogens. these bacteria are categorized as plant growth promoting rhizobacteria (pgpr) and are associated with plant roots. knowledge of the underlying mechanisms of plant growth promotion in vivo is still very limited, but interference of bacteria with plant hormone metabolism is suggested to play a major role. to obtain new growth promoting bacteria, ...201222580689
regulation of polyphosphate kinase production by antisense rna in pseudomonas fluorescens pf0-1.pseudomonas spp. adapt rapidly to environmental fluctuations. loss or overproduction of polyphosphate reduces the fitness of pseudomonas fluorescens pf0-1, indicating the importance of the fine-tuning of polyphosphate production. an antisense rna was investigated and shown to regulate the polyphosphate kinase gene (ppk) by a posttranscriptional mechanism reducing ppk transcript abundance.201222492458
evolutionary and experimental assessment of novel markers for detection of xanthomonas euvesicatoria in plant samples.bacterial spot-causing xanthomonads (bsx) are quarantine phytopathogenic bacteria responsible for heavy losses in tomato and pepper production. despite the research on improved plant spraying methods and resistant cultivars, the use of healthy plant material is still considered as the most effective bacterial spot control measure. therefore, rapid and efficient detection methods are crucial for an early detection of these phytopathogens.201222655073
a widespread bacterial type vi secretion effector superfamily identified using a heuristic approach.sophisticated mechanisms are employed to facilitate information exchange between interfacing bacteria. a type vi secretion system (t6ss) of pseudomonas aeruginosa was shown to deliver cell wall-targeting effectors to neighboring cells. however, the generality of bacteriolytic effectors and, moreover, of antibacterial t6s remained unknown. using parameters derived from experimentally validated bacterial t6ss effectors we identified a phylogenetically disperse superfamily of t6ss-associated peptid ...201222607806
pseudomonad swarming motility is restricted to a narrow range of high matric water potentials.using a novel experimental system that allows control of the matric potential of an agar slab, we explored the hydration conditions under which swarming motility is possible. if there is recognition that this physical parameter is a key determinant of swarming, it is usually neither controlled nor measured rigorously but only manipulated through proxies, namely, the agar concentration and the drying time of "soft" agar plates (swarming plates). we contend that this not only obscures the biophysi ...201222327576
plastid genetic engineering in solanaceae.plastid genetic engineering has come of age, becoming today an attractive alternative approach for the expression of foreign genes, as it offers several advantages over nuclear transformants. significant progress has been made in plastid genetic engineering in tobacco and other solanaceae plants, through the use of improved regeneration procedures and transformation vectors with efficient promoters and untranslated regions. many genes encoding for industrially important proteins and vaccines, as ...201222395455
computational prediction and molecular characterization of an oomycete effector and the cognate arabidopsis resistance gene.hyaloperonospora arabidopsidis (hpa) is an obligate biotroph oomycete pathogen of the model plant arabidopsis thaliana and contains a large set of effector proteins that are translocated to the host to exert virulence functions or trigger immune responses. these effectors are characterized by conserved amino-terminal translocation sequences and highly divergent carboxyl-terminal functional domains. the availability of the hpa genome sequence allowed the computational prediction of effectors and ...201222359513
biodegradation of low density polythene (ldpe) by pseudomonas species.low density polythene (ldpe) is the most widely used packaging material primarily because of its excellent mechanical properties, barrier properties against water, light weight, low cost and high energy effectiveness. however, due to its ubiquitous nature, and resistance to biodegradability, the disposal strategies are crucial and need attention. recently, microorganisms have become the focus of interest for environmental friendly disposal of plastic and polymer-based waste. this manuscript aims ...201223997333
phytosterols play a key role in plant innate immunity against bacterial pathogens by regulating nutrient efflux into the apoplast.bacterial pathogens colonize a host plant by growing between the cells by utilizing the nutrients present in apoplastic space. while successful pathogens manipulate the plant cell membrane to retrieve more nutrients from the cell, the counteracting plant defense mechanism against nonhost pathogens to restrict the nutrient efflux into the apoplast is not clear. to identify the genes involved in nonhost resistance against bacterial pathogens, we developed a virus-induced gene-silencing-based fast- ...201222298683
pseudomonas biofilm matrix composition and niche biology.biofilms are a predominant form of growth for bacteria in the environment and in the clinic. critical for biofilm development are adherence, proliferation, and dispersion phases. each of these stages includes reinforcement by, or modulation of, the extracellular matrix. pseudomonas aeruginosa has been a model organism for the study of biofilm formation. additionally, other pseudomonas species utilize biofilm formation during plant colonization and environmental persistence. pseudomonads produce ...201222212072
characterisation of the mgo operon in pseudomonas syringae pv. syringae umaf0158 that is required for mangotoxin production.mangotoxin is an antimetabolite toxin that is produced by strains of pseudomonas syringae pv. syringae; mangotoxin-producing strains are primarily isolated from mango tissues with symptoms of bacterial apical necrosis. the toxin is an oligopeptide that inhibits ornithine n-acetyl transferase (oat), a key enzyme in the biosynthetic pathway of the essential amino acids ornithine and arginine. the involvement of a putative nonribosomal peptide synthetase gene (mgoa) in mangotoxin production and vir ...201222251433
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 ...201322986789
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 ...201322978428
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 ...201323067202
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 ...201323062058
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 ...201323061987
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 ...201323043909
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 ...201323167462
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 ...201323142764
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 ...201323102875
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 ...201323099348
lov-domain photoreceptor, encoded in a genomic island, attenuates the virulence of pseudomonas syringae in light-exposed arabidopsis leaves.in arabidopsis thaliana, light signals modulate the defences against bacteria. here we show that light perceived by the lov domain-regulated two-component system (pst-lov) of pseudomonas syringae pv. tomato dc3000 (pst dc3000) modulates virulence against a. thaliana. bioinformatic analysis and the existence of an episomal circular intermediate indicate that the locus encoding pst-lov is present in an active genomic island acquired by horizontal transfer. strains mutated at pst-lov showed enhance ...201323865633
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