| dirhamnose-lipid production by recombinant nonpathogenic bacterium pseudomonas chlororaphis. | we previously discovered that pseudomonas chlororaphis nrrl b-30761 produces monorhamnolipids (r1ls) with predominantly 3-hydroxydodecenoyl-3-hydroxydecanoate (c12:1-c10) or 3-hydroxydodecanoyl-3-hydroxydecanoate (c12-c10) as the lipid moiety under static growth conditions only. we have now cloned, sequenced, and analyzed in silico the gene locus of nrrl b-30761 containing the putative coding sequences of rhamnosyltransferase chain a (rhla pch , 894 bps), rhamnosyltransferase chain b (rhlb pch , ... | 2015 | 25661819 |
| tomato response traits to pathogenic pseudomonas species: does nitrogen limitation matter? | induced chemical defence is a cost-efficient protective strategy, whereby plants induce the biosynthesis of defence-related compounds only in the case of pest attack. plant responses that are pathogen specific lower the cost of defence, compared to constitutive defence. as nitrogen availability (n) in the root zone is one of the levers mediating the concentration of defence-related compounds in plants, we investigated its influence on response traits of tomato to two pathogenic bacteria, growing ... | 2016 | 26810453 |
| production of a de-novo designed antimicrobial peptide in nicotiana benthamiana. | antimicrobial peptides are important defense compounds of higher organisms that can be used as therapeutic agents against bacterial and/or viral infections. we designed several antimicrobial peptides containing hydrophobic and positively charged clusters that are active against plant and human pathogens. especially peptide sp1-1 is highly active with a mic value of 0.1 μg/ml against xanthomonas vesicatoria, pseudomonas corrugata and pseudomonas syringae pv syringae. however, for commercial appli ... | 2013 | 23242916 |
| effectors from wheat rust fungi suppress multiple plant defense responses. | fungi that cause cereal rust diseases (genus puccinia) are important pathogens of wheat globally. upon infection, the fungus secretes a number of effector proteins. although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. in this study, we mined the available transcriptomes of puccinia graminis and p. striiformis to look for potential effec ... | 2017 | 27503371 |
| the stripe rust fungal effector pec6 suppresses pattern-triggered immunity in a host species-independent manner and interacts with adenosine kinases. | we identified a wheat stripe rust (puccinia striiformis) effector candidate (pec6) with pattern-triggered immunity (pti) suppression function and its corresponding host target. pec6 compromised pti host species-independently. in nicotiana benthamiana, it hampers reactive oxygen species (ros) accumulation and callose deposition induced by pseudomonas fluorescens. in arabidopsis, plants expressing pec6 were more susceptible to pseudomonas syringae pv. tomato (pto) dc3000 δavrpto/δavrptob. in wheat ... | 2016 | 27252028 |
| characterization of ice-nucleating bacteria using on-line electron impact ionization aerosol mass spectrometry. | the mass spectral signatures of airborne bacteria were measured and analyzed in cloud simulation experiments at the aida (aerosol interaction and dynamics in the atmosphere) facility. suspensions of cultured cells in pure water were sprayed into the aerosol and cloud chambers forming an aerosol which consisted of intact cells, cell fragments and residual particles from the agar medium in which the bacteria were cultured. the aerosol particles were analyzed with a high-resolution time-of-flight a ... | 2015 | 26149110 |
| characterization of the ability to form biofilms by plant-associated pseudomonas species. | successful colonization is the initial step for plant-bacteria interactions; therefore, the development of strategies to improve adherence to plant surfaces is critically important for environmental bacteria. biofilm formation is thought to be one such strategy for bacteria to establish stable colonization on inert and living surfaces. although biofilms play potential roles in enabling persistent bacterial colonization, little attention has been paid to biofilms formed by plant-associated bacter ... | 2015 | 25487118 |
| eggplant and related species are promising genetic resources to dissect the plant immune response to pseudomonas syringae and xanthomonas euvesicatoria and to identify new resistance determinants. | the apparent lack of durability of many resistance (r) genes highlights the need for the constant identification of new genetic sources of resistance for the breeding of new disease-resistant crop cultivars. to this end, we screened a collection of accessions of eggplant and close relatives for resistance against pseudomonas syringae pv. tomato (pto) and xanthomonas euvesicatoria (xeu), foliar plant pathogens of many solanaceous crops. both pathogens caused substantial disease on most genotypes ... | 2014 | 24684604 |
| diversity and abundance of phyllosphere bacteria are linked to insect herbivory. | simultaneous or sequential attack by herbivores and microbes is common in plants. many seed plants exhibit a defence trade-off against chewing herbivorous insects and leaf-colonizing ('phyllosphere') bacteria, which arises from cross-talk between the phytohormones jasmonic acid (ja, induced by many herbivores) and salicylic acid (sa, induced by many bacteria). this cross-talk may promote reciprocal susceptibility in plants between phyllosphere bacteria and insect herbivores. in a population of n ... | 2014 | 24383417 |
| pseudomonas asturiensis sp. nov., isolated from soybean and weeds. | five strains of gram negative bacteria, isolated from soybean (lppa 221(t), 222 and 223) and weeds (lppa 816 and 1442), were analyzed by a polyphasic approach. the isolates showed variation in their phenotypic traits and were placed in the pseudomonas fluorescens lineage, based on 16s rrna gene sequence phylogeny, as a single but well separated cluster. mlsa analysis based on gyrb and rpod sequences clustered the strains in a single branch in the pseudomonas syringae group, and revealed p. virid ... | 2013 | 23727430 |
| induced systemic resistance in arabidopsis thaliana against pseudomonas syringae pv. tomato by 2,4-diacetylphloroglucinol-producing pseudomonas fluorescens. | pseudomonas fluorescens strains that produce the polyketide antibiotic 2,4-diacetylphloroglucinol (2,4-dapg) are among the most effective rhizobacteria that suppress root and crown rots, wilts, and damping-off diseases of a variety of crops, and they play a key role in the natural suppressiveness of some soils to certain soilborne pathogens. root colonization by 2,4-dapg-producing p. fluorescens strains pf-5 (genotype a), q2-87 (genotype b), q8r1-96 (genotype d), and ht5-1 (genotype n) produced ... | 2012 | 22409433 |
| a bacterial cysteine protease effector protein interferes with photosynthesis to suppress plant innate immune responses. | the bacterial pathogen pseudomonas syringae pv tomato dc3000 suppresses plant innate immunity with effector proteins injected by a type iii secretion system (t3ss). the cysteine protease effector hopn1, which reduces the ability of dc3000 to elicit programmed cell death in non-host tobacco, was found to also suppress the production of defence-associated reactive oxygen species (ros) and callose when delivered by pseudomonas fluorescens heterologously expressing a p. syringae t3ss. purified his(6 ... | 2012 | 22233353 |
| isolation and partial characterization of bacteriophages infecting pseudomonas syringae pv. actinidiae, causal agent of kiwifruit bacterial canker. | the phytopathogen pseudomonas syringae pv. actinidiae (psa) is the causal agent of bacterial canker of kiwifruit. in the last years, it has caused severe economic losses to actinidia spp. cultivations, mainly in italy and new zealand. conventional strategies adopted did not provide adequate control of infection. phage therapy may be a realistic and safe answer to the urgent need for novel antibacterial agents aiming to control this bacterial pathogen. in this study, we described the isolation an ... | 2014 | 24810619 |
| pseudomonas putida kt2440 causes induced systemic resistance and changes in arabidopsis root exudation. | pseudomonas putida kt2440 is an efficient colonizer of the rhizosphere of plants of agronomical and basic interest. we have demonstrated that kt2440 can protect the model plant arabidopsis thaliana against infection by the phytopathogen pseudomonas syringae pv. tomato dc3000. p. putida extracellular haem-peroxidase (pp2561) was found to be important for competitive colonization and essential for the induction of plant systemic resistance. root exudates of plants elicited by kt2440 exhibited dist ... | 2010 | 23766110 |
| plasmid replicons from pseudomonas are natural chimeras of functional, exchangeable modules. | plasmids are a main factor for the evolution of bacteria through horizontal gene exchange, including the dissemination of pathogenicity genes, resistance to antibiotics and degradation of pollutants. their capacity to duplicate is dependent on their replication determinants (replicon), which also define their bacterial host range and the inability to coexist with related replicons. we characterize a second replicon from the virulence plasmid ppsv48c, from pseudomonas syringae pv. savastanoi, whi ... | 2017 | 28243228 |
| indole-3-acetic acid in plant-pathogen interactions: a key molecule for in planta bacterial virulence and fitness. | the plant pathogenic bacterium pseudomonas savastanoi, the causal agent of olive and oleander knot disease, uses the so-called "indole-3-acetamide pathway" to convert tryptophan to indole-3-acetic acid (iaa) via a two-step pathway catalyzed by enzymes encoded by the genes in the iaam/iaah operon. moreover, pathovar nerii of p. savastanoi is able to conjugate iaa to lysine to generate the less biologically active compound iaa-lys via the enzyme iaa-lysine synthase encoded by the iaal gene. intere ... | 2017 | 27637152 |
| differential modulation of plant immune responses by diverse members of the pseudomonas savastanoi pv. savastanoi hopaf type iii effector family. | the pseudomonas savastanoi pv. savastanoi ncppb 3335 type iii secretion system (t3ss) effector repertoire includes 33 candidates, seven of which translocate into host cells and interfere with plant defences. the present study was performed to investigate the co-existence of both plasmid- and chromosomal-encoded members of the hopaf effector family, hopaf1-1 and hopaf1-2, respectively, in the genome of ncppb 3335. here, we show that the hopaf1 paralogues are widely distributed in the pseudomonas ... | 2016 | 27116193 |
| [pathogenic miko,- and microflora of fraxinus excelsior in podolya ukraine]. | the article summarizes our research results of pathogenic myco- and microflora, as well as harmful entomofauna on european ash. it is shown that the most common and harmful diseaseis tuberculosis (its causal agent--bacteria pseudomonas syringae pv.savastanoi (smith 1908), which affects trunks, branches, twigs and buds of european ash. it describes a number of pathogens and representatives mikofitozov malicious entomofauna that by virtue of its activities significantly weaken the growth, developm ... | 2015 | 26638486 |
| genetically modified luminescent bacteria ralostonia solanacerum, pseudomonas syringae, pseudomonas savastanoi, and wild type bacterium vibrio fischeri in biosynthesis of gold nanoparticles from gold chloride trihydrate. | the effect of different genetically engineered bacteria, pseudomonas syringae, pseudomonas savastanoi, and ralostonia solanacerum and also a natural marine bacterial species, vibrio fischeri nrrl b-11177, is studied in producing gold nanoparticles. this is the first report about the biosynthesis of gold nanoparticles by natural and genetically engineered luminescent bacteria. these microorganisms reduced gold ions and produced fairly monodisperse nanoparticles. tem analysis indicated that spheri ... | 2014 | 25088536 |
| new insights into the role of indole-3-acetic acid in the virulence of pseudomonas savastanoi pv. savastanoi. | indole-3-acetic acid (iaa) is a widespread phytohormone among plant-associated bacteria, including the tumour-inducing pathogen of woody hosts, pseudomonas savastanoi pv. savastanoi. a phylogenetic analysis of the iaam/iaah operon, which is involved in the biosynthesis of iaa, showed that one of the two operons encoded by pseudomonas savastanoi pv. savastanoi ncppb 3335, iaam-1/iaah-1, is horizontally transferred among bacteria belonging to the pseudomonas syringae complex. we also show that bio ... | 2014 | 24606017 |
| translocation and functional analysis of pseudomonas savastanoi pv. savastanoi ncppb 3335 type iii secretion system effectors reveals two novel effector families of the pseudomonas syringae complex. | pseudomonas savastanoi pv. savastanoi ncppb 3335 causes olive knot disease and is a model pathogen for exploring bacterial infection of woody hosts. the type iii secretion system (t3ss) effector repertoire of this strain includes 31 effector candidates plus two novel candidates identified in this study which have not been reported to translocate into plant cells. in this work, we demonstrate the delivery of seven ncppb 3335 effectors into nicotiana tabacum leaves, including three proteins from t ... | 2014 | 24329173 |
| [effect of host change on phages 223 -17 and 7591-14 pseudomonas savastanoi pv. tabaci]. | we studied the characteristics of phages 223-17 7591-14 grown on the strains of pseudomonas syringae pv. tabaci, on the intermediate host of p. savastanoi pv. phaseolicola and after their returning to original. it was found, that phages grown on pv. phaseolicola acquired ability to cause lysis of previously resistant strains p. viridiflava (phage 223-17) and p. fluorecens (phage 7591-14). it was common that, when making the restriction analysis of dna of phages grown on pv tabaci, the formation ... | 2013 | 23866590 |
| identification of novel virulence genes and metabolic pathways required for full fitness of pseudomonas savastanoi pv. savastanoi in olive (olea europaea) knots. | comparative genomics and functional analysis of pseudomonas syringae and related pathogens have mainly focused on diseases of herbaceous plants; however, there is a general lack of knowledge about the virulence and pathogenicity determinants required for infection of woody plants. here, we applied signature-tagged mutagenesis (stm) to pseudomonas savastanoi pv. savastanoi during colonization of olive (olea europaea) knots, with the goal of identifying the range of genes linked to growth and symp ... | 2012 | 23088618 |
| virulence of pseudomonas syringae pv. tomato dc3000 is influenced by the catabolite repression control protein crc. | pseudomonas syringae infects diverse plant species and is widely used as a model system in the study of effector function and the molecular basis of plant diseases. although the relationship between bacterial metabolism, nutrient acquisition, and virulence has attracted increasing attention in bacterial pathology, it is largely unexplored in p. syringae. the crc (catabolite repression control) protein is a putative rna-binding protein that regulates carbon metabolism as well as a number of other ... | 2017 | 28384054 |
| origin and evolution of the kiwifruit canker pandemic. | recurring epidemics of kiwifruit (actinidia spp.) bleeding canker disease are caused by pseudomonas syringae pv. actinidiae (psa). in order to strengthen understanding of population structure, phylogeography and evolutionary dynamics, we isolated pseudomonas from cultivated and wild kiwifruit across six provinces in china. based on the analysis of eighty sequenced psa genomes we show that china is the origin of the pandemic lineage but that strain diversity in china is confined to just a single ... | 2017 | 28369338 |
| the bacterial effector avrb-induced rin4 hyperphosphorylation is mediated by receptor-like cytoplasmic kinase complex in arabidopsis. | bacterial pathogen pseudomonas syringae delivers diverse type iii effectors into host cells to interfere with their immune responses. one of the effectors avrb targets a host guardee protein rin4 and induces rin4 phosphorylation in arabidopsis. phosphorylated rin4 activates the immune receptor rpm1 to mount defense. avrb-induced rin4 phosphorylation depends on ripk, a receptor-like cytoplasmic kinase (rlck). in this study, we found several other rlcks that were also able to phosphorylate rin4. w ... | 2017 | 28353399 |
| population-genomic insights into emergence, crop adaptation and dissemination of pseudomonas syringae pathogens. | many bacterial pathogens are well characterized but, in some cases, little is known about the populations from which they emerged. this limits understanding of the molecular mechanisms underlying disease. the crop pathogen pseudomonas syringae sensu lato has been widely isolated from the environment, including wild plants and components of the water cycle, and causes disease in several economically important crops. here, we compared genome sequences of 45 p. syringae crop pathogen outbreak strai ... | 2016 | 28348830 |
| rin4 recruits the exocyst subunit exo70b1 to the plasma membrane. | the exocyst is a conserved vesicle-tethering complex with principal roles in cell polarity and morphogenesis. several studies point to its involvement in polarized secretion during microbial pathogen defense. in this context, we have found an interaction between the arabidopsis exo70b1 exocyst subunit, a protein which was previously associated with both the defense response and autophagy, and rpm1 interacting protein 4 (rin4), the best studied member of the noi protein family and a known regulat ... | 2017 | 28338727 |
| bivariate genomic analysis identifies a hidden locus associated with bacteria hypersensitive response in arabidopsis thaliana. | multi-phenotype analysis has drawn increasing attention to high-throughput genomic studies, whereas only a few applications have justified the use of multivariate techniques. we applied a recently developed multi-trait analysis method on a small set of bacteria hypersensitive response phenotypes and identified a single novel locus missed by conventional single-trait genome-wide association studies. the detected locus harbors a minor allele that elevates the risk of leaf collapse response to the ... | 2017 | 28338080 |
| diversity and abundance of ice nucleating strains of pseudomonas syringae in a freshwater lake in virginia, usa. | the bacterium pseudomonas syringae is found in a variety of terrestrial and aquatic environments. some strains of p. syringae express an ice nucleation protein (hereafter referred to as ice+) allowing them to catalyze the heterogeneous freezing of water. though p. syringae has been sampled intensively from freshwater sources in france, little is known about the genetic diversity of p. syringae in natural aquatic habitats in north america. we collected samples of freshwater from three different d ... | 2017 | 28337177 |
| biochemical principles and functional aspects of pipecolic acid biosynthesis in plant immunity. | the non-protein amino acid pipecolic acid (pip) regulates plant systemic acquired resistance (sar) and basal immunity to bacterial pathogen infection. in arabidopsis thaliana, the lys aminotransferase agd2-like defense response protein1 (ald1) mediates the pathogen-induced accumulation of pip in inoculated and distal leaf tissue. here we show that ald1 transfers the alpha-amino group of l-lys to acceptor oxoacids. combined mass spectrometric and infrared spectroscopic analyses of in vitro assays ... | 2017 | 28330936 |
| use of rna-seq data to identify and validate rt-qpcr reference genes for studying the tomato-pseudomonas pathosystem. | the agronomical relevant tomato-pseudomonas syringae pv. tomato pathosystem is widely used to explore and understand the underlying mechanisms of the plant immune response. transcript abundance estimation, mainly through reverse transcription-quantitative pcr (rt-qpcr), is a common approach employed to investigate the possible role of a candidate gene in certain biological process under study. the accuracy of this technique relies heavily on the selection of adequate reference genes. initially, ... | 2017 | 28317896 |
| controlled ice nucleation using freeze-dried pseudomonas syringae encapsulated in alginate beads. | the control of ice nucleation is of fundamental significance in many process technologies related to food and pharmaceutical science and cryobiology. mechanical perturbation, electromagnetic fields and ice-nucleating agents (inas) have been known to induce ice nucleation in a controlled manner. but these ice-nucleating methods may suffer from cumbersome manual operations, safety concerns of external fields, and biocompatibility and recovery issues of ina particles, especially when used in living ... | 2017 | 28315320 |
| diverse mechanisms of resistance to pseudomonas syringae in a thousand natural accessions of arabidopsis thaliana. | plants are continuously threatened by pathogen attack and, as such, they have evolved mechanisms to evade, escape and defend themselves against pathogens. however, it is not known what types of defense mechanisms a plant would already possess to defend against a potential pathogen that has not co-evolved with the plant. we addressed this important question in a comprehensive manner by studying the responses of 1041 accessions of arabidopsis thaliana to the foliar pathogen pseudomonas syringae pv ... | 2017 | 28295393 |
| ghanamycins a and b, two novel γ-butyrolactones from marine-derived streptomyces ghanaensis txc6-16. | two novel γ-butyrolactones ghanamycins a (1) and b (2) were isolated from the fermentation broth of marine-derived streptomyces ghanaensis txc6-16. their structures were elucidated by spectroscopic analysis. these two novel compounds exhibited antimicrobial activities against some phytopathogens. the minimum ic (mic) of 2 against pseudomonas syringae and erwinia sp. were 50 μg ml(-1).the journal of antibiotics advance online publication, 15 march 2017; doi:10.1038/ja.2017.37. | 2017 | 28293035 |
| expanded type iii effector recognition by the zar1 nlr protein using zed1-related kinases. | nucleotide-binding domain and leucine-rich repeat domain-containing (nlr) proteins are sentinels of plant immunity that monitor host proteins for perturbations induced by pathogenic effector proteins. here we show that the arabidopsis zar1 nlr protein requires the zrk3 kinase to recognize the pseudomonas syringae type iii effector (t3e) hopf2a. these results support the hypothesis that zar1 associates with an expanded zrk protein family to broaden its effector recognition spectrum. | 2017 | 28288096 |
| map kinase signaling pathways: a hub of plant-microbe interactions. | in 2007, we reported that a phytopathogen effector directly inhibits a map kinase cascade. in the decade since, many more effectors have been found to inhibit map kinase cascades, providing not only a mechanistic understanding of pathogenesis and immunity in plants, but also the identification of previously unknown enzymes. | 2017 | 28279328 |
| thienopyrimidine-type compounds protect arabidopsis plants against the hemibiotrophic fungal pathogen colletotrichum higginsianum and bacterial pathogen pseudomonas syringae pv. maculicola. | plant activators activate systemic acquired resistance-like defense responses or induced systemic resistance, and thus protect plants from pathogens. we screened a chemical library composed of structurally diverse small molecules. we isolated six plant immune-inducing thienopyrimidine-type compounds and their analogous compounds. it was observed that the core structure of thienopyrimidine plays a role in induced resistance in plants. furthermore, we highlight the protective effect of thienopyrim ... | 2017 | 28277972 |
| analyses of natural variation indicates that the absence of rps4/rrs1 and amino acid change in rps4 cause loss of their functions and resistance to pathogens. | a pair of arabidopsis thaliana resistance proteins, rps4 and rrs1, recognizes the cognate avr effector from the bacterial pathogens pseudomonas syringae pv. tomato expressing avrrps4 (pst-avrrps4), ralstonia solanacearum, and the fungal pathogen colletotrichum higginsianum and leads to defense signaling activation against the pathogens. in the present study, we analyzed 14 a. thaliana accessions for natural variation in pst-avrrps4 and c. higginsianum susceptibility, and found new compatible and ... | 2017 | 28277970 |
| reconstruction of an immune dynamic model to simulate the contrasting role of auxin and cytokinin in plant immunity. | in order to increase our understanding of biological dependencies in plant immune signaling pathways, the known interactions involved in plant immune networks are modeled. this allows computational analysis to predict the functions of growth related hormones in plant-pathogen interaction. the squad (standardized qualitative dynamical systems) algorithm first determines stable system states in the network and then use them to compute continuous dynamical system states. our reconstructed boolean m ... | 2017 | 28265989 |
| microbial manipulation of auxins and cytokinins in plants. | microbial associations with plants are crucial for the survival of both the partners. beside other ways of establishing such associations, phytohormones enjoy a key role in plant-microbe interactions from initial dialog between the two to the establishment of a viable partnership. cytokinins (cks) and iaa are among the five classical groups of phytohormones implicated in plant immune response, early signaling, and deciding the fate of interactions between plant and microbes. here we describe a m ... | 2017 | 28265987 |
| chemical composition, antioxidant and biological activities of the essential oil and extract of the seeds of glycine max (soybean) from north iran. | glycine max (l.) merrill (soybean) is a major leguminous crop, cultivated globally as well as in iran. this study examines the chemical composition of soybean essential oil, and evaluates the antioxidant and antimicrobial activities of seeds on various plant pathogens that commonly cause irreparable damages to agricultural crops. the essential oil of soybean seeds was analyzed by gas chromatography coupled to mass spectrometry. antimicrobial activity was tested against 14 microorganisms, includi ... | 2017 | 28255785 |
| cytokinin-mediated regulation of reactive oxygen species homeostasis modulates stomatal immunity in arabidopsis. | stomata play an important role in preinvasive defense responses by limiting pathogen entry into leaves. although the stress hormones salicylic acid (sa) and abscisic acid (aba) are known to regulate stomatal immunity, the role of growth promoting hormones is far from understood. here, we show that in arabidopsis thaliana, cytokinins (cks) function in stomatal defense responses. the cytokinin receptor histidine kinase3 (ahk3) and response regulator2 (arr2) promote stomatal closure triggered by pa ... | 2017 | 28254779 |
| transposon insertion libraries for the characterization of mutants from the kiwifruit pathogen pseudomonas syringae pv. actinidiae. | pseudomonas syringae pv. actinidiae (psa), the causal agent of kiwifruit canker, is one of the most devastating plant diseases of recent times. we have generated two mini-tn5-based random insertion libraries of psa icmp 18884. the first, a 'phenotype of interest' (poi) library, consists of 10,368 independent mutants gridded into 96-well plates. by replica plating onto selective media, the poi library was successfully screened for auxotrophic and motility mutants. lipopolysaccharide (lps) biosynt ... | 2017 | 28249011 |
| ethylene production with engineered synechocystis sp pcc 6803 strains. | metabolic engineering and synthetic biology of cyanobacteria offer a promising sustainable alternative approach for fossil-based ethylene production, by using sunlight via oxygenic photosynthesis, to convert carbon dioxide directly into ethylene. towards this, both well-studied cyanobacteria, i.e., synechocystis sp pcc 6803 and synechococcus elongatus pcc 7942, have been engineered to produce ethylene by introducing the ethylene-forming enzyme (efe) from pseudomonas syringae pv. phaseolicola pk2 ... | 2017 | 28231787 |
| genome-wide analysis of chromatin accessibility in arabidopsis infected with pseudomonas syringae. | changes in chromatin accessibility are an important aspect of the molecular changes that occur in eukaryotic cells responding to stress, and they appear to play a critical role in stress-induced transcriptional activation/reprogramming and epigenetic changes. in plants, pathogen infection has been shown to induce rapid and drastic transcriptional reprogramming; growing evidence suggests that chromatin remodeling plays an essential role in this phenomenon. the recent development of genomic tools ... | 2017 | 28220432 |
| characterizing the immune-eliciting activity of putative microbe-associated molecular patterns in tomato. | detection of conserved microbe-associated molecular patterns (mamps), such as bacterial flagellin, is the first line of active defense in plants against pathogenic invaders. successful pathogens must subvert this immune response to grow to high population density and cause disease. flagellin from the bacterial pathogen pseudomonas was the first identified bacterial mamp and many species across the plant kingdom have sensitive perception systems for detecting the 22-amino acid epitope known as fl ... | 2017 | 28220431 |
| quantitative evaluation of plant actin cytoskeletal organization during immune signaling. | high spatial and temporal resolution microscopy-based methods are valuable tools for the precise real-time imaging of changes in cellular organization in response to stimulus perception. here, we describe a quantitative method for the evaluation of the plant actin cytoskeleton during immune stimulus perception and the activation of defense signaling. as a measure of the biotic stress-induced changes in actin filament organization, we present methods for analyzing changes in actin filament organi ... | 2017 | 28220427 |
| measuring callose deposition, an indicator of cell wall reinforcement, during bacterial infection in arabidopsis. | the plant cell wall responds dynamically during interaction with various pathogens. upon recognition of "nonself" components, plant cells deploy a variety of immune responses including cell wall fortification. callose, a β-(1, 3)-d-glucan polymer, is a component of the material deposited at the site of infection between the plasma membrane and the preexisting cell wall that is hypothesized to serve as a physical barrier and platform for directed antimicrobial compound deposition. the defense-ass ... | 2017 | 28220426 |
| adaptation of the pathogen, pseudomonas syringae, during experimental evolution on a native vs. alternative host plant. | the specialization and distribution of pathogens among species has substantial impact on disease spread, especially when reservoir hosts can maintain high pathogen densities or select for increased pathogen virulence. theory predicts that optimal within-host growth rate will vary among host genotypes/species and therefore that pathogens infecting multiple hosts should experience different selection pressures depending on the host environment in which they are found. this should be true for patho ... | 2017 | 28207977 |
| characterization of pseudomonas syringae pv. syringae, causal agent of citrus blast of mandarin in montenegro. | citrus blast caused by bacterium pseudomonas syringae is a very important disease of citrus occuring in many areas of the world, but with few data about genetic structure of the pathogen involved. considering the above fact, this study reports genetic characterization of 43 p. syringae isolates obtained from plant tissue displaying citrus blast symptoms on mandarin (citrus reticulata) in montenegro, using multilocus sequence analysis of gyrb, rpod, and gap1 gene sequences. gene sequences from a ... | 2017 | 28167885 |
| tomato photorespiratory glycolate oxidase-derived h2 o2 production contributes to basal defense against pseudomonas syringae. | despite being essential for c3 plants, photorespiration is believed to cause a significant crop yield loss even under future climates. however, how photorespiration affects plant basal defense still remains largely unknown. here, we studied the involvement of photorespiration in tomato-pseudomonas syringae pv. tomato dc3000 interaction focusing on three photorespiratory genes. inoculation with p. syringae increased photorespiration rate (pr) and expression of glycolate oxidase (gox2), serine gly ... | 2017 | 28164315 |
| transgenic arabidopsis thaliana containing increased levels of atp and sucrose is more susceptible to pseudomonas syringae. | disease resistance exerts a fitness cost on plants, presumably due to the extra consumption of energy and carbon. in this study, we examined whether transgenic arabidopsis thaliana with increased levels of atp and sucrose is more resistant or susceptible to pathogen infection. lines of a. thaliana over-expressing purple acid phosphatase 2 (atpap2) (oe lines) contain increased levels of atp and sucrose, with improved growth rate and seed production. compared to wild type (wt) and pap2 lines, the ... | 2017 | 28152090 |
| the arabidopsis elongator complex is required for nonhost resistance against the bacterial pathogens xanthomonas citri subsp. citri and pseudomonas syringae pv. phaseolicola nps3121. | although in recent years nonhost resistance has attracted considerable attention for its broad spectrum and durability, the genetic and mechanistic components of nonhost resistance have not been fully understood. we used molecular and histochemical approaches including quantitative pcr, chromatin immunoprecipitation, and 3,3'-diaminobenzidine and aniline blue staining. the evolutionarily conserved histone acetyltransferase complex elongator was identified as a major component of nonhost resistan ... | 2017 | 28134437 |
| n-acylhomoserine lactone-regulation of genes mediating motility and pathogenicity in pseudomonas syringae pathovar tabaci 11528. | pseudomonas syringae pathovar tabaci 11528 (p. syringae 11528) is a phytopathogen that causes wild-fire disease in soybean and tobacco plants. it utilizes a cell density-dependent regulation system known as quorum sensing (qs). in its qs system, the psyi is responsible for the biosynthesis of n-acylhomoserine lactones (ahls). by comparing the transcripts from p. syringae 11528 wild-type strain with those of the δpsyi mutant using rna sequencing (rna-seq) technology, 1118 ahl-regulated genes were ... | 2017 | 28133926 |
| pseudomonas syringae type iii effector hopbb1 promotes host transcriptional repressor degradation to regulate phytohormone responses and virulence. | independently evolved pathogen effectors from three branches of life (ascomycete, eubacteria, and oomycete) converge onto the arabidopsis tcp14 transcription factor to manipulate host defense. however, the mechanistic basis for defense control via tcp14 regulation is unknown. we demonstrate that tcp14 regulates the plant immune system by transcriptionally repressing a subset of the jasmonic acid (ja) hormone signaling outputs. a previously unstudied pseudomonas syringae (psy) type iii effector, ... | 2017 | 28132837 |
| constitutive heterologous overexpression of a tir-nb-arc-lrr gene encoding a putative disease resistance protein from wild chinese vitis pseudoreticulata in arabidopsis and tobacco enhances resistance to phytopathogenic fungi and bacteria. | plants use resistance (r) proteins to detect pathogen effector proteins and activate their innate immune response against the pathogen. the majority of these proteins contain an nb-arc (nucleotide-binding adaptor shared by apaf-1, r proteins, and ced-4) domain along with a leucine-rich repeat (lrr), and some also bear a toll interleukin 1 receptor (tir) domain. in this study, we characterized a gene encoding a tir-nb-arc-lrr r protein (vptnl1) (genbank accession number kx649890) from wild chines ... | 2017 | 28131063 |
| confocal microscopy reveals in planta dynamic interactions between pathogenic, avirulent and non-pathogenic pseudomonas syringae strains. | recent advances in genomics and single-cell analysis have demonstrated the extraordinary complexity that microbial populations may reach within their hosts. communities range from complex multispecies groups, to homogeneous populations differentiating into lineages through genetic or non-genetic mechanisms. diversity within bacterial populations is recognised as a key driver of the evolution of animal pathogens. in plants, however, little is known about how interactions between different pathoge ... | 2017 | 28120374 |
| paraburkholderia phytofirmans psjn protects arabidopsis thaliana against a virulent strain of pseudomonas syringae through the activation of induced resistance. | paraburkholderia phytofirmans psjn is a plant growth-promoting rhizobacterium (pgpr) that stimulates plant growth and improves tolerance to abiotic stresses. this study analyzed whether strain psjn can reduce plant disease severity and proliferation of the virulent strain pseudomonas syringae pv. tomato dc3000, in arabidopsis plants, through the activation of induced resistance. arabidopsis plants previously exposed to strain psjn showed a reduction in disease severity and pathogen proliferation ... | 2017 | 28118091 |
| use of the soft-agar overlay technique to screen for bacterially produced inhibitory compounds. | the soft-agar overlay technique was originally developed over 70 years ago and has been widely used in several areas of microbiological research, including work with bacteriophages and bacteriocins, proteinaceous antibacterial agents. this approach is relatively inexpensive, with minimal resource requirements. this technique consists of spotting supernatant from a donor strain (potentially harboring a toxic compound(s)) onto a solidified soft agar overlay that is seeded with a bacterial test str ... | 2017 | 28117830 |
| subunit-selective proteasome activity profiling uncovers uncoupled proteasome subunit activities during bacterial infections. | the proteasome is a nuclear-cytoplasmic proteolytic complex involved in nearly all regulatory pathways in plant cells. the three different catalytic activities of the proteasome can have different functions, but tools to monitor and control these subunits selectively are not yet available in plant science. here, we introduce subunit-selective inhibitors and dual-color fluorescent activity-based probes for studying two of the three active catalytic subunits of the plant proteasome. we validate th ... | 2017 | 28117509 |
| identification of loci of pseudomonas syringae pv. actinidiae involved in lipolytic activity and their role in colonization of kiwifruit leaves. | bacterial canker disease caused by pseudomonas syringae pv. actinidiae, an emerging pathogen of kiwifruit plants, has recently brought about major economic losses worldwide. genetic studies on virulence functions of p. syringae pv. actinidiae have not yet been reported and there is little experimental data regarding bacterial genes involved in pathogenesis. in this study, we performed a genetic screen in order to identify transposon mutants altered in the lipolytic activity because it is known t ... | 2017 | 28112597 |
| tomato slggp-like gene participates in plant responses to chilling stress and pathogenic infection. | plants are always exposed to abiotic and biotic stresses which can adversely affect their growth and development. as an important antioxidant, asa plays a vital role in plant defence against damage caused by stresses. in this study, we cloned a tomato gdp-l-galactose phosphorylase-like (slggp-like) gene and investigated its role in resistance to abiotic and biotic stresses by using antisense transgenic (as) tomato lines. the asa content in as plants was lower than that in wt plants. under chilli ... | 2017 | 28092850 |
| the trojan horse coronatine: the coi1-jaz2-myc2,3,4-anac019,055,072 module in stomata dynamics upon bacterial infection. | | 2017 | 28079932 |
| the conserved hypothetical protein pspto_3957 is essential for virulence in the plant pathogen pseudomonas syringae pv. tomato dc3000. | the plant pathogen pseudomonas syringae accounts for substantial crop losses and is considered an important agricultural issue. to better manage disease in the field, it is important to have an understanding of the underlying genetic mechanisms that mediate virulence. there are a substantial number of genes in sequenced bacterial genomes, including p. syringae, that encode for conserved hypothetical proteins; some of these have been functionally characterized in other pseudomonads and have been ... | 2017 | 28073812 |
| nup82 functions redundantly with nup136 in a salicylic acid-dependent defense response of arabidopsis thaliana. | the nuclear pore complex (npc) comprises more than 30 nucleoporins (nups). npc mediates macromolecular trafficking between the nucleoplasm and the cytoplasm, but specific roles of individual nups are poorly understood in higher plants. here, we show that the novel nucleoporin unique to angiosperm plants (designated as nup82) functions in a salicylic acid-dependent defense in a redundant manner with nup136, which is a component of the nuclear basket in the npc. arabidopsis thaliana nup82 had a si ... | 2017 | 28071978 |
| evolution of copper resistance in the kiwifruit pathogen pseudomonas syringae pv. actinidiae through acquisition of integrative conjugative elements and plasmids. | horizontal gene transfer can precipitate rapid evolutionary change. in 2010 the global pandemic of kiwifruit canker disease caused by pseudomonas syringae pv. actinidiae (psa) reached new zealand. at the time of introduction, the single clone responsible for the outbreak was sensitive to copper, however, analysis of a sample of isolates taken in 2015 and 2016 showed that a quarter were copper resistant. genome sequences of seven strains showed that copper resistance - comprising czc/cusabc and c ... | 2017 | 28063194 |
| protein phosphatase ap2c1 negatively regulates basal resistance and defense responses to pseudomonas syringae. | mitogen-activated protein kinases (mapks) mediate plant immune responses to pathogenic bacteria. however, less is known about the cell autonomous negative regulatory mechanism controlling basal plant immunity. we report the biological role of arabidopsis thaliana mapk phosphatase ap2c1 as a negative regulator of plant basal resistance and defense responses to pseudomonas syringae ap2c2, a closely related mapk phosphatase, also negatively controls plant resistance. loss of ap2c1 leads to enhanced ... | 2017 | 28062592 |
| arabidopsis stress associated protein 9 mediates biotic and abiotic stress responsive aba signaling via the proteasome pathway. | arabidopsis thaliana stress associated protein 9 (atsap9) is a member of the a20/an1 zinc finger protein family known to play important roles in plant stress responses and in the mammalian immune response. although saps of several plant species were shown to be involved in abiotic stress responses, the underlying molecular mechanisms are largely unknown, and little is known about the involvement of saps in plant disease responses. expression of sap9 in arabidopsis is up-regulated in response to ... | 2017 | 28039858 |
| profiling the extended phenotype of plant pathogens: challenges in bacterial molecular plant pathology. | one of the most fundamental questions in plant pathology is what determines whether a pathogen grows within a plant? this question is frequently studied in terms of the role of elicitors and pathogenicity factors in the triggering or overcoming of host defences. however, this focus fails to address the basic question of how the environment in host tissues acts to support or restrict pathogen growth. efforts to understand this aspect of host-pathogen interactions are commonly confounded by severa ... | 2017 | 28026146 |
| coronatine inhibits stomatal closure through guard cell-specific inhibition of nadph oxidase-dependent ros production. | microbes trigger stomatal closure through microbe-associated molecular patterns (mamps). the bacterial pathogen pseudomonas syringae pv. tomato (pst) synthesizes the polyketide toxin coronatine, which inhibits stomatal closure by mamps and by the hormone abscisic acid (aba). the mechanism by which coronatine, a jasmonic acid-isoleucine analog, achieves this effect is not completely clear. reactive oxygen species (ros) are essential second messengers in stomatal immunity, therefore we investigate ... | 2016 | 28018388 |
| jaz2 controls stomata dynamics during bacterial invasion. | coronatine (cor) facilitates entry of bacteria into the plant apoplast by stimulating stomata opening. cor-induced signaling events at stomata remain unclear. we found that the cor and jasmonate isoleucine (ja-ile) co-receptor jaz2 is constitutively expressed in guard cells and modulates stomatal dynamics during bacterial invasion we analyzed tissue expression patterns of atjaz genes and measured stomata opening and pathogen resistance in loss- and gain-of-function mutants. arabidopsis jaz2 muta ... | 2017 | 28005270 |
| the putative kinase substrate muse7 negatively impacts the accumulation of nlr proteins. | stringent modulation of immune signaling in plants is necessary to enable a rapid response to pathogen attack without spurious defense activation. to identify genes involved in plant immunity, a forward genetic screen for enhancers of the autoimmune snc1 (suppressor of npr1, constitutive 1) mutant was conducted. the snc1 mutant contains a gain-of-function mutation in a gene encoding a nod-like receptor (nlr) protein. the isolated muse7 (mutant, snc1-enhancing, 7) mutant was shown to confer a rev ... | 2017 | 28004865 |
| gaba (γ-aminobutyric acid) uptake via the gaba permease gabp represses virulence gene expression in pseudomonas syringae pv. tomato dc3000. | the nonprotein amino acid γ-aminobutyric acid (gaba) is the most abundant amino acid in the tomato (solanum lycopersicum) leaf apoplast and is synthesized by arabidopsis thaliana in response to infection by the bacterial pathogen pseudomonas syringae pv. tomato dc3000 (hereafter called dc3000). high levels of exogenous gaba have previously been shown to repress the expression of the type iii secretion system (t3ss) in dc3000, resulting in reduced elicitation of the hypersensitive response (hr) i ... | 2016 | 28001093 |
| erratum to: development of scar markers for rapid and specific detection of pseudomonas syringae pv. morsprunorum races 1 and 2, using conventional and real-time pcr. | | 2017 | 27999901 |
| image-based quantification of plant immunity and disease. | measuring the extent and severity of disease is a critical component of plant pathology research and crop breeding. unfortunately, existing visual scoring systems are qualitative, subjective, and the results are difficult to transfer between research groups, while existing quantitative methods can be quite laborious. here, we present plant immunity and disease image-based quantification (pidiq), a quantitative, semi-automated system to rapidly and objectively measure disease symptoms in a biolog ... | 2016 | 27996374 |
| characterization of two late-stage enzymes involved in fosfomycin biosynthesis in pseudomonads. | the broad-spectrum phosphonate antibiotic fosfomycin is currently in use for clinical treatment of infections caused by both gram-positive and gram-negative uropathogens. the antibiotic is biosynthesized by various streptomycetes, as well as by pseudomonads. notably, the biosynthetic strategies used by the two genera share only two steps: the first step in which primary metabolite phosphoenolpyruvate (pep) is converted to phosphonopyruvate (pnpy) and the terminal step in which 2-hydroxypropylpho ... | 2017 | 27977135 |
| overexpression of panax ginseng sesquiterpene synthase gene confers tolerance against pseudomonas syringae pv. tomato in arabidopsis thaliana. | sesquiterpenes are an abundant group belonging to the terpenoid family, with a c15 structure comprise of three isoprene units. many sesquiterpenes are volatile compounds and it act as chemical messenger in plant signalling, particularly in the defense mechanism against biotic and abiotic stresses. panax ginseng meyer is important medicinal herbs with various reported pharmacological efficacies in which its triterpenoid saponins, called ginsenosides, were mostly studied. however, there have been ... | 2016 | 27924121 |
| the hemileia vastatrix effector hvec-016 suppresses bacterial blight symptoms in coffee genotypes with the sh 1 rust resistance gene. | a number of genes that confer resistance to coffee leaf rust (sh 1-sh 9) have been identified within the genus coffea, but despite many years of research on this pathosystem, the complementary avirulence genes of hemileia vastatrix have not been reported. after identification of h. vastatrix effector candidate genes (hvecs) expressed at different stages of its lifecycle, we established an assay to characterize hvec proteins by delivering them into coffee cells via the type-three secretion system ... | 2017 | 27918080 |
| a subset of ubiquitin-conjugating enzymes is essential for plant immunity. | of the three classes of enzymes involved in ubiquitination, ubiquitin-conjugating enzymes (e2) have been often incorrectly considered to play merely an auxiliary role in the process, and few e2 enzymes have been investigated in plants. to reveal the role of e2 in plant innate immunity, we identified and cloned 40 tomato genes encoding ubiquitin e2 proteins. thioester assays indicated that the majority of the genes encode enzymatically active e2. phylogenetic analysis classified the 40 tomato e2 ... | 2017 | 27909045 |
| arabidopsis thaliana methionine sulfoxide reductase b8 influences stress-induced cell death and effector-triggered immunity. | reactive oxygen species (ros) oxidize methionine to methionine sulfoxide (metso) and thereby inactivate proteins. methionine sulfoxide reductase (msr) enzyme converts metso back to the reduced form and thereby detoxifies the effect of ros. our results show that arabidopsis thaliana msr enzyme coding gene msrb8 is required for effector-triggered immunity and containment of stress-induced cell death in arabidopsis. plants activate pattern-triggered immunity (pti), a basal defense, upon recognition ... | 2017 | 27900506 |
| a conserved puccinia striiformis protein interacts with wheat npr1 and reduces induction of pathogenesis-related genes in response to pathogens. | in arabidopsis, npr1 is a key transcriptional coregulator of systemic acquired resistance. upon pathogen challenge, npr1 translocates from the cytoplasm to the nucleus, in which it interacts with tga-bzip transcription factors to activate the expression of several pathogenesis-related (pr) genes. in a screen of a yeast two-hybrid library from wheat leaves infected with puccinia striiformis f. sp. tritici, we identified a conserved rust protein that interacts with wheat npr1 and named it pnpi (fo ... | 2016 | 27898286 |
| the pattern-recognition receptor core of solanaceae detects bacterial cold-shock protein. | plants and animals recognize microbial invaders by detecting microbe-associated molecular patterns (mamps) by cell surface receptors. many plant species of the solanaceae family detect the highly conserved nucleic acid binding motif rnp-1 of bacterial cold-shock proteins (csps), represented by the peptide csp22, as a mamp. here, we exploited the natural variation in csp22 perception observed between cultivated tomato (solanum lycopersicum) and solanum pennellii to map and identify the leucine-ri ... | 2016 | 27892924 |
| bacteria establish an aqueous living space in plants crucial for virulence. | high humidity has a strong influence on the development of numerous diseases affecting the above-ground parts of plants (the phyllosphere) in crop fields and natural ecosystems, but the molecular basis of this humidity effect is not understood. previous studies have emphasized immune suppression as a key step in bacterial pathogenesis. here we show that humidity-dependent, pathogen-driven establishment of an aqueous intercellular space (apoplast) is another important step in bacterial infection ... | 2016 | 27882964 |
| infection assays in arabidopsis reveal candidate effectors from the poplar rust fungus that promote susceptibility to bacteria and oomycete pathogens. | fungi of the pucciniales order cause rust diseases which, altogether, affect thousands of plant species worldwide and pose a major threat to several crops. how rust effectors-virulence proteins delivered into infected tissues to modulate host functions-contribute to pathogen virulence remains poorly understood. melampsora larici-populina is a devastating and widespread rust pathogen of poplar, and its genome encodes 1184 identified small secreted proteins that could potentially act as effectors. ... | 2016 | 27868319 |
| evaluation of a loop-mediated isothermal amplification assay based on hrpz gene for rapid detection and identification of pseudomonas syringae pv. lachrymans in cucumber leaves. | cucumber angular leaf spot caused by pseudomonas syringae pv. lachrymans (psl) is an important and destructive disease worldwide, and no effective technique has been developed for the control of the pathogen. detection of infection or latent in cucumber plants is critical to evaluate disease progress and strengthening management to avoid a serious epidemic in the fields. in this paper, we developed a rapid and sensitive method for detection of psl using an isothermal method known as loop-mediate ... | 2017 | 27864860 |
| n-(3-oxo-hexanoyl)-homoserine lactone has a critical contribution to the quorum-sensing-dependent regulation in phytopathogen pseudomonas syringae pv. tabaci 11528. | the phytopathogen pseudomonas syringae pv. tabaci 11528 (p. syringae 11528), causing wild-fire disease in soybean and tobacco plants, processes psyi-psyr quorum-sensing (qs) system, in which psyi is the n-(3-oxo-hexanoyl)-homoserine lactone (3oc6-hsl) synthase. in comparison to p. syringae 11528 ahl-deficient mutant, 845 3oc6-hsl-dependent genes were identified using rna sequencing (rna-seq) in the ahl-deficient mutant grown with exogenous 3oc6-hsl in the transition from the exponential to the s ... | 2016 | 27864298 |
| melatonin is required for h2 o2 - and no-mediated defense signaling through mapkkk3 and oxi1 in arabidopsis thaliana. | melatonin influences plant innate immunity through the mitogen-activated protein kinase (mapk) pathway. however, the most upstream mapk component in melatonin signaling and the dependence of generation of a reactive oxygen species (ros) burst on melatonin synthesis and signaling remain unclear. in this study, treatment of several mekk (alias mapkkk)-knockout arabidopsis mutants with melatonin revealed that the mapkkk3 and oxi1 (oxidative signal-inducible1) kinases are responsible for triggering ... | 2017 | 27862280 |
| subcellular localization of pseudomonas syringae pv. tomato effector proteins in plants. | animal and plant pathogenic bacteria use type iii secretion systems to translocate proteinaceous effectors to subvert innate immunity of their host organisms. type iii secretion/effector systems are a crucial pathogenicity factor in many bacterial pathogens of plants and animals. pseudomonas syringae pv. tomato (pst) dc3000 injects a total of 36 protein effectors that target a variety of host proteins. studies of a subset of pst dc3000 effectors demonstrated that bacterial effectors, once inside ... | 2017 | 27837488 |
| cml8, an arabidopsis calmodulin-like protein, plays a role in pseudomonas syringae plant immunity. | calcium is a universal second messenger involved in various cellular processes including plant development and stress responses. its conversion into biological responses requires the presence of calcium sensor relays such as calmodulin (cam) and calmodulin-like (cml) proteins. while the role of cam is well described, the functions cml proteins remain largely uncharacterized. here, we show that arabidopsis cml8 expression is strongly and transiently induced by pseudomonas syringae, and reverse ge ... | 2017 | 27837097 |
| teaching an old dog new tricks: suppressing activation of specific mitogen-activated kinases as a potential virulence function of the bacterial avrrpt2 effector protein. | avrrpt2 is one of the first pseudomonas syringae effector proteins demonstrated to be delivered into host cells. it suppresses plant immunity by modulating auxin signaling and cleavage of the membrane-localized defense regulator rin4. we recently uncovered a novel potential virulence function of avrrpt2, where it specifically blocked activation of mitogen-activated protein kinases, mpk4 and mpk11, but not of mpk3 and mpk6. putative avrrpt2 homologs from different phytopathogens and plant-associa ... | 2016 | 27830985 |
| lon protease is involved in rhprs-mediated regulation of type iii secretion in pseudomonas syringae. | pseudomonas syringae depends on the type iii secretion system (t3ss) to directly translocate effectors into host cells. previously, we reported a nonpathogenic rhps mutant, suggesting that the two-component transduction system rhprs is an important regulator of t3ss in p. syringae. rhprs regulates itself and a variety of downstream genes under an inverted repeat element promoter in a phosphorylation-dependent manner. here, we identify lon as a suppressor of the rhps mutant through transposon scr ... | 2016 | 27657922 |
| transcription factor anac032 modulates ja/sa signalling in response to pseudomonas syringae infection. | responses to pathogens, including host transcriptional reprogramming, require partially antagonistic signalling pathways dependent on the phytohormones salicylic (sa) and jasmonic (ja) acids. however, upstream factors modulating the interplay of these pathways are not well characterized. here, we identify the transcription factor anac032 from arabidopsis thaliana as one such regulator in response to the bacterial pathogen pseudomonas syringae pv. tomato dc3000 (pst). anac032 directly represses m ... | 2016 | 27632992 |
| evolution, genomics and epidemiology of pseudomonas syringae: challenges in bacterial molecular plant pathology. | a remarkable shift in our understanding of plant-pathogenic bacteria is underway. until recently, nearly all research on phytopathogenic bacteria was focused on a small number of model strains, which provided a deep, but narrow, perspective on plant-microbe interactions. advances in genome sequencing technologies have changed this by enabling the incorporation of much greater diversity into comparative and functional research. we are now moving beyond a typological understanding of a select coll ... | 2017 | 27798954 |
| biophysical characterization of soluble pseudomonas syringae ice nucleation protein inaz fragments. | ice nucleation protein (inp) with its functional domain consisting of multiple 48-residue repeat units effectively induces super-cooled water into ice. circular dichroism and infrared deconvolution analyses on a soluble 240-residue fragment of pseudomonas syringae inaz (inaz240) containing five 48-residue repeat units indicated that it is mostly composed of β-sheet and random coil. analytical ultracentrifugation suggested that inaz240 behaves as a monomer of an elongated ellipsoid. however, inaz ... | 2017 | 27773839 |
| altered meristem program1 has conflicting effects on the tolerance to heat shock and symptom development after pseudomonas syringae infection. | an arabidopsis thaliana altered meristem program1 (atamp1), which encodes a putative glutamate carboxypeptidase, not only controls shoot apical meristem development, but also is involved in tolerance response to abiotic stresses. here, we introduce a novel mutant; named amp1-32 that is a phenocopier to previously isolated different amp1 mutant alleles. interestingly, tiny leaves were continuously developed at the bottom of pre-emerged leaves in the amp1-32. the amp1-32 mutant was less sensitive ... | 2016 | 27743891 |
| inhibitor discovery by convolution abpp. | activity-based protein profiling (abpp) has emerged as a powerful proteomic approach to study the active proteins in their native environment by using chemical probes that label active site residues in proteins. traditionally, abpp is classified as either comparative or competitive abpp. in this protocol, we describe a simple method called convolution abpp, which takes benefit from both the competitive and comparative abpp. convolution abpp allows one to detect if a reduced signal observed durin ... | 2017 | 27778280 |
| exogenous n-acyl-homoserine lactones enhance the expression of flagella of pseudomonas syringae and activate defence responses in plants. | in order to cope with pathogens, plants have evolved sophisticated mechanisms to sense pathogenic attacks and to induce defence responses. the n-acyl-homoserine lactone (ahl)-mediated quorum sensing in bacteria regulates diverse physiological processes, including those involved in pathogenicity. in this work, we study the interactions between ahl-producing transgenic tobacco plants and pseudomonas syringae pv. tabaci 11528 (p. syringae 11528). both a reduced incidence of disease and decrease in ... | 2016 | 27756102 |
| development and validation of an infection risk model for bacterial canker of kiwifruit, using a multiplication and dispersal concept for forecasting bacterial diseases. | a weather-based disease prediction model for bacterial canker of kiwifruit (known worldwide as psa; pseudomonas syringae pv. actinidiae biovar 3) was developed using a new mechanistic scheme for bacterial disease forecasters, the multiplication and dispersal concept. bacterial multiplication is estimated from a temperature function, the m index, accumulated from hourly air temperature over 3 days for hours when the leaf canopy is wet. rainfall provides free water to move inoculum to infection si ... | 2017 | 27749150 |
| activation-dependent destruction of a co-receptor by a pseudomonas syringae effector dampens plant immunity. | the arabidopsis immune receptor fls2 and co-receptor bak1 perceive the bacterial flagellin epitope flg22 to activate plant immunity. to prevent this response, phytopathogenic bacteria deploy a repertoire of effector proteins to perturb immune signaling. however, the effector-induced perturbation is often sensed by the host, triggering another layer of immunity. we report that the pseudomonas syringae effector hopb1 acts as a protease to cleave immune-activated bak1. prior to activation, hopb1 co ... | 2016 | 27736646 |