Publications

efficient virus-induced gene silencing in arabidopsis.	virus-induced gene silencing (vigs) is a plant rna-silencing technique that uses viral vectors carrying a fragment of a gene of interest to generate double-stranded rna, which initiates the silencing of the target gene. several viral vectors have been developed for vigs and they have been successfully used in reverse genetics studies of a variety of processes occurring in plants. this approach has not been widely adopted for the model dicotyledonous species arabidopsis (arabidopsis thaliana), po ...	2006	16815951
the brucella abortus cyclic beta-1,2-glucan virulence factor is substituted with o-ester-linked succinyl residues.	brucella periplasmic cyclic beta-1,2-glucan plays an important role during bacterium-host interaction. nuclear magnetic resonance spectrometry analysis, thin-layer chromatography, and deae-sephadex chromatography were used to characterize brucella abortus cyclic glucan. in the present study, we report that a fraction of b. abortus cyclic beta-1,2-glucan is substituted with succinyl residues, which confer anionic character on the cyclic beta-1,2-glucan. the oligosaccharide backbone is substituted ...	2006	16816173
an arabidopsis homologue of human seven-in-absentia-interacting protein is involved in pathogen resistance.	human seven-in-absentia (siah)-interacting protein (sip) is a component of the e3 ligase complex targeting beta-catenin for destruction. arabidopsis has one sip protein (atsip) with 32% amino acid sequence identity to sip. to investigate the functions of atsip, we isolated an atsip knockout mutant, and generated transgenic plants overexpressing atsip. the growth rates and morphologies of the atsip and transgenic plants were indistinguishable from those of wild type. however, atsip plants were mo ...	2006	16819302
prediction of csra-regulating small rnas in bacteria and their experimental verification in vibrio fischeri.	the role of small rnas as critical components of global regulatory networks has been highlighted by several recent studies. an important class of such small rnas is represented by csrb and csrc of escherichia coli, which control the activity of the global regulator csra. given the critical role played by csra in several bacterial species, an important problem is the identification of csra-regulating small rnas. in this paper, we develop a computer program (csrna_find) designed to locate potentia ...	2006	16822857
double hexameric ring assembly of the type iii protein translocase atpase hrcn.	the specialized type iii secretion (t3s) apparatus of pathogenic and symbiotic gram-negative bacteria comprises a complex transmembrane organelle and an atpase homologous to the f1-atpase beta subunit. the t3s atpase hrcn of pseudomonas syringae associates with the inner membrane, and its atp hydrolytic activity is stimulated by dodecamerization. the structure of dodecameric hrcn (hrcn12) determined to 1.6 nm by cryo-electron microscopy is presented. hrcn12 comprises two hexameric rings that are ...	2006	16824099
a mutation in the gtp hydrolysis site of arabidopsis dynamin-related protein 1e confers enhanced cell death in response to powdery mildew infection.	we screened for mutants of arabidopsis thaliana that displayed enhanced disease resistance to the powdery mildew pathogen erysiphe cichoracearum and identified the edr3 mutant, which formed large gray lesions upon infection with e. cichoracearum and supported very little sporulation. the edr3-mediated disease resistance and cell death phenotypes were dependent on salicylic acid signaling, but independent of ethylene and jasmonic acid signaling. in addition, edr3 plants displayed enhanced suscept ...	2006	16824181
functional expression of mammalian nadph-cytochrome p450 oxidoreductase on the cell surface of escherichia coli.	to develop a whole-cell oxidoreductase system without the practical limitation of substrate/product transport, easy preparation, stability of enzymes, and low expression levels, we here report the development of a whole cell biocatalyst displaying rat nadph-cytochrome p450 oxidoreductase (cpr, 77-kda) on the surface of escherichia coli by using ice-nucleation protein from pseudomonas syringae. surface localization and functionality of the cpr were verified by flow cytometry, electron microscopy, ...	2006	16829136
herbivore-induced resistance against microbial pathogens in arabidopsis.	caterpillars of the herbivore pieris rapae stimulate the production of jasmonic acid (ja) and ethylene (et) in arabidopsis (arabidopsis thaliana) and trigger a defense response that affects insect performance on systemic tissues. to investigate the spectrum of effectiveness of p. rapae-induced resistance, we examined the level of resistance against different pathogens. although the necrotrophic fungus alternaria brassicicola is sensitive to ja-dependent defenses, herbivore-induced resistance was ...	2006	16829584
corr regulates multiple components of virulence in pseudomonas syringae pv. tomato dc3000.	the phytotoxin coronatine (cor) is produced by various pathovars of pseudomonas syringae, including p. syringae pv. tomato dc3000, which is pathogenic on crucifers and tomato, and p. syringae pv. glycinea pg4180, a soybean pathogen. the cor molecule contains two distinct components, coronafacic acid (cfa) and coronamic acid (cma), which are intermediates in the cor biosynthetic pathway. in p. syringae pv. tomato dc3000, it is not clear whether corr, which encodes a response regulator, positively ...	2006	16838789
the arabidopsis thaliana jasmonate insensitive 1 gene is required for suppression of salicylic acid-dependent defenses during infection by pseudomonas syringae.	many plant pathogens suppress antimicrobial defenses using virulence factors that modulate endogenous host defenses. the pseudomonas syringae phytotoxin coronatine (cor) is believed to promote virulence by acting as a jasmonate analog, because cor-insensitive 1 (coil) arabidopsis thaliana and tomato mutants are impaired in jasmonate signaling and exhibit reduced susceptibility to p. syringae. to further investigate the role of jasmonate signaling in disease development, we analyzed several jasmo ...	2006	16838791
a bacterial virulence protein suppresses host innate immunity to cause plant disease.	plants have evolved a powerful immune system to defend against infection by most microbial organisms. however, successful pathogens, such as pseudomonas syringae, have developed countermeasures and inject virulence proteins into the host plant cell to suppress immunity and cause devastating diseases. despite intensive research efforts, the molecular targets of bacterial virulence proteins that are important for plant disease development have remained obscure. here, we show that a conserved p. sy ...	2006	16840699
polyamine oxidase is one of the key elements for oxidative burst to induce programmed cell death in tobacco cultured cells.	programmed cell death plays a critical role during the hypersensitive response in the plant defense system. one of components that triggers it is hydrogen peroxide, which is generated through multiple pathways. one example is proposed to be polyamine oxidation, but direct evidence for this has been limited. in this article, we investigated relationships among polyamine oxidase, hydrogen peroxide, and programmed cell death using a model system constituted of tobacco (nicotiana tabacum) cultured c ...	2006	16844838
tobacco tsip1, a dnaj-type zn finger protein, is recruited to and potentiates tsi1-mediated transcriptional activation.	tobacco stress-induced1 (tsi1) is an ethylene-responsive-element binding protein/apetala2-type transcription factor that plays an important role in both biotic and abiotic stress signaling pathways. we show that tsi1-interacting protein1 (tsip1), a dnaj-type zn finger protein, interacts with tsi1 in vitro and in yeast (saccharomyces cerevisiae). the transcript level of tsip1 in tobacco (nicotiana tabacum) increased upon treatment with salicylic acid (sa), ethylene, gibberellic acid, nacl, and vi ...	2006	16844903
development of a virus-induced gene-silencing system for functional analysis of the rps2-dependent resistance signalling pathways in arabidopsis.	virus-induced gene silencing (vigs) offers a rapid and high throughput technique platform for the analysis of gene function in plants. although routinely used in some solanaceous species, vigs system has not been well established in arabidopsis thaliana (l.) heynh. we have recently reported some factors that potentially influence tobacco rattle virus (trv)-mediated vigs of phytoene desaturase (pds) and actin gene expression in arabidopsis. in this study, we have further established that the agro ...	2006	16845481
the defh9-iaam-containing construct efficiently induces parthenocarpy in cucumber.	parthenocarpy (seedless fruits) is a desirable trait that has been achieved in many plant cultivars. we generated parthenocarpic cucumber fruits by introducing the chimeric defh9-iaam construct into the cucumber genome using an agrobacterium tumefaciens-mediated protocol. the construct consists of the defh9 promoter from antirrhinum majus and the iaam coding sequence from pseudomonas syringae. transgenic plants were obtained from nine independent transformation events: half of these were tetrapl ...	2006	16847572
analysis of the defence phosphoproteome of arabidopsis thaliana using differential mass tagging.	despite recent advances in proteomic technologies, quantitative analysis of the proteome remains a challenging task. phosphorylation of proteins is central to signal transduction pathways and plays an important role in plant defence against pathogens, although the immediate targets of kinases remain elusive. determining changes in the phosphoproteome during the defence response is a major goal in molecular plant pathology. in this first description of the novel mass tagging strategy (itraq appli ...	2006	16850419
formation of functional tat translocases from heterologous components.	the tat pathway transports folded proteins across the cytoplasmic membrane of bacteria and the thylakoid membrane of plants. in eschericha coli, tat transport requires the integral membrane proteins tata, tatb and tatc. in this study we have tested the ability of tat genes from the eubacterial species pseudomonas syringae, streptomyces coelicolor and aquifex aeolicus, to compensate for the absence of the cognate e. coli tat gene, and thus to form functional tat translocases with e. coli tat comp ...	2006	16854235
ectopic expression of the cotton non-symbiotic hemoglobin gene ghhbd1 triggers defense responses and increases disease tolerance in arabidopsis.	plant non-symbiotic hemoglobins (nshbs) play important roles in a variety of cellular processes. previous evidence from this laboratory indicates that the expression of a class 1 nshb gene (ghhb1) from cotton is induced in cotton roots challenged with the verticillium wilt fungus. the present study examined further the expression patterns of the ghhb1 gene in cotton plants and characterized its in vivo function through ectopic overexpression of the gene in arabidopsis thaliana. expression of ghh ...	2006	16854938
crystal structure of a type iii pantothenate kinase: insight into the mechanism of an essential coenzyme a biosynthetic enzyme universally distributed in bacteria.	pantothenate kinase (pank) catalyzes the first step in the five-step universal pathway of coenzyme a (coa) biosynthesis, a key transformation that generally also regulates the intracellular concentration of coa through feedback inhibition. a novel pank protein encoded by the gene coax was recently identified that is distinct from the previously characterized type i pank (exemplified by the escherichia coli coaa-encoded pank protein) and type ii eukaryotic panks and is not inhibited by coa or its ...	2006	16855243
identification and characterization of an azotobacter vinelandii type i secretion system responsible for export of the alge-type mannuronan c-5-epimerases.	alginate is a linear copolymer of beta-d-mannuronic acid and its c-5-epimer, alpha-l-guluronic acid. during biosynthesis, the polymer is first made as mannuronan, and various fractions of the monomers are then epimerized to guluronic acid by mannuronan c-5-epimerases. the azotobacter vinelandii genome encodes a family of seven extracellular such epimerases (alge1 to alge7) which display motifs characteristic for proteins secreted via a type i pathway. putative atpase-binding cassette regions fro ...	2006	16855245
a role for a flavin-containing mono-oxygenase in resistance against microbial pathogens in arabidopsis.	using activation tagging in the arabidopsis col-0 rps2-101c background, we identified a mutant (fmo1-3d) that showed virtually no symptoms after inoculation with virulent pseudomonas syringae pv. tomato dc3000 bacteria. the dominant, gain-of-function phenotype of the fmo1-3d mutant is due to over-expression of a class 3 flavin-containing mono-oxygenase (fmo). we recapitulated the fmo1-3d mutant phenotype in independent transgenic col-0 lines over-expressing the fmo1 cdna under the control of the ...	2006	16856982
identification of 17 pseudomonas aeruginosa srnas and prediction of srna-encoding genes in 10 diverse pathogens using the bioinformatic tool srnapredict2.	srnas are small, non-coding rna species that control numerous cellular processes. although it is widely accepted that srnas are encoded by most if not all bacteria, genome-wide annotations for srna-encoding genes have been conducted in only a few of the nearly 300 bacterial species sequenced to date. to facilitate the efficient annotation of bacterial genomes for srna-encoding genes, we developed a program, srnapredict2, that identifies putative srnas by searching for co-localization of genetic ...	2006	16870723
microbial colonization and competition on the marine alga ulva australis.	pseudalteromonas tunicata and roseobacter gallaeciensis are biofilm-forming marine bacteria that are often found in association with the surface of the green alga ulva australis. they are thought to benefit the plant host by producing inhibitory compounds that are active against common fouling organisms. we investigated factors that influence the ability of p. tunicata and r. gallaeciensis to attach to and colonize the plant surface and also the competitive interactions that occur between these ...	2006	16885308
the entry mechanism of membrane-containing phage bam35 infecting bacillus thuringiensis.	the temperate double-stranded dna bacteriophage bam35 infects gram-positive bacillus thuringiensis cells. bam35 has an icosahedral protein coat surrounding the viral membrane that encloses the linear 15-kbp dna genome. the protein coat of bam35 uses the same assembly principle as that of prd1, a lytic bacteriophage infecting gram-negative hosts. in this study, we dissected the process of bam35 entry into discrete steps: receptor binding, peptidoglycan penetration, and interaction with the plasma ...	2006	16885461
peroxidase-dependent apoplastic oxidative burst in arabidopsis required for pathogen resistance.	the oxidative burst is an early response to pathogen attack leading to the production of reactive oxygen species (ros) including hydrogen peroxide. two major mechanisms involving either nadph oxidases or peroxidases that may exist singly or in combination in different plant species have been proposed for the generation of ros. we identified an arabidopsis thaliana azide-sensitive but diphenylene iodonium-insensitive apoplastic oxidative burst that generates h(2)o(2) in response to a fusarium oxy ...	2006	16889645
the arabidopsis thaliana tir-nb-lrr r-protein, rpp1a; protein localization and constitutive activation of defence by truncated alleles in tobacco and arabidopsis.	specific recognition of hyaloperonospora parasitica isolate cala2 by arabidopsis thaliana ws-0 is mediated by the resistance gene rpp1a. transient expression of different truncations of rpp1a in tobacco leaves revealed that its tir-nb-arc portion is sufficient to induce an elicitor-independent cell death. in stable transgenic lines of arabidopsis, overexpression of the rpp1a tir-nb-arc domains (e12) using the 35s promoter leads to broad-spectrum resistance to virulent strains of h. parasitica an ...	2006	16889647
transgenic tobacco plants overexpressing chitinases of fungal origin show enhanced resistance to biotic and abiotic stress agents.	genes encoding defense-related proteins have been used to alter the resistance of plants to pathogens and other environmental challenges, but no single fungal gene overexpression has produced broad-spectrum stress resistance in transgenic lines. we have generated transgenic tobacco (nicotiana tabacum) lines that overexpress the endochitinases chit33 and chit42 from the mycoparasitic fungus trichoderma harzianum and have evaluated their tolerance to biotic and abiotic stress. both chit33 and chit ...	2006	16891545
characterization of the mrgrs locus of the opportunistic pathogen burkholderia pseudomallei: temperature regulates the expression of a two-component signal transduction system.	burkholderia pseudomallei is a saprophyte in tropical environments and an opportunistic human pathogen. this versatility requires a sensing mechanism that allows the bacterium to respond rapidly to altered environmental conditions. we characterized a two-component signal transduction locus from b. pseudomallei 204, mrgr and mrgs, encoding products with extensive homology with response regulators and histidine protein kinases of escherichia coli, bordetella pertussis, and vibrio cholerae.	2006	16893462
investigation of potential antibacterial properties of methanol extracts from fungus ganoderma applanatum.	in this study we searched for antibacterial compounds in methanol extracts of three layers (tube layer, context and cutis) of ganoderma applanatum fruit body against bacillus subtilis atcc 6051 as a gram-positive bacterium and escherichia coli atcc 25922 and pseudomonas syringae pv. syringae dpic 219 as gram-negative bacteria. we found antibacterial properties in all three layers only against gram-negative bacteria. the fractions were isolated and purified by thin layer chromatography (tlc) and ...	2006	16899973
identification and functional expression of the pepper pathogen-induced gene, capip2, involved in disease resistance and drought and salt stress tolerance.	a novel pathogen-induced gene, designated capip2, was isolated from pepper leaves infected with xanthomonas campestris pv. vesicatoria. capip2:gfp fusion proteins were primarily localized in the cytoplasm. the capip2 transcripts were constitutively expressed in the pepper leaves, flowers, and fruits, but were not detected in the stems and roots. capip2 gene expression was induced strongly in the pepper leaves during pathogen infection, and also after exposure to abiotic elicitors and environment ...	2006	16900319
random mutagenesis in corynebacterium glutamicum atcc 13032 using an is6100-based transposon vector identified the last unknown gene in the histidine biosynthesis pathway.	corynebacterium glutamicum, a gram-positive bacterium of the class actinobacteria, is an industrially relevant producer of amino acids. several methods for the targeted genetic manipulation of this organism and rational strain improvement have been developed. an efficient transposon mutagenesis system for the completely sequenced type strain atcc 13032 would significantly advance functional genome analysis in this bacterium.	2006	16901339
genome comparison using gene ontology (go) with statistical testing.	automated comparison of complete sets of genes encoded in two genomes can provide insight on the genetic basis of differences in biological traits between species. gene ontology (go) is used as a common vocabulary to annotate genes for comparison. current approaches calculate the fold of unweighted or weighted differences between two species at the high-level go functional categories. however, to ensure the reliability of the differences detected, it is important to evaluate their statistical si ...	2006	16901353
gacs-dependent production of 2r, 3r-butanediol by pseudomonas chlororaphis o6 is a major determinant for eliciting systemic resistance against erwinia carotovora but not against pseudomonas syringae pv. tabaci in tobacco.	root colonization by a plant-beneficial rhizobacterium, pseudomonas chlororaphis o6, induces disease resistance in tobacco against leaf pathogens erwinia carotovora subsp. carotovora scc1, causing soft-rot, and pseudomonas syringae pv. tabaci, causing wildfire. in order to identify the bacterial determinants involved in induced systemic resistance against plant diseases, extracellular components produced by the bacterium were fractionated and purified. factors in the culture filtrate inducing sy ...	2006	16903358
the structural basis for promoter -35 element recognition by the group iv sigma factors.	the control of bacterial transcription initiation depends on a primary sigma factor for housekeeping functions, as well as alternative sigma factors that control regulons in response to environmental stresses. the largest and most diverse subgroup of alternative sigma factors, the group iv extracytoplasmic function sigma factors, directs the transcription of genes that regulate a wide variety of responses, including envelope stress and pathogenesis. we determined the 2.3-a resolution crystal str ...	2006	16903784
multiple avirulence paralogues in cereal powdery mildew fungi may contribute to parasite fitness and defeat of plant resistance.	powdery mildews, obligate biotrophic fungal parasites on a wide range of important crops, can be controlled by plant resistance (r) genes, but these are rapidly overcome by parasite mutants evading recognition. it is unknown how this rapid evolution occurs without apparent loss of parasite fitness. r proteins recognize avirulence (avr) molecules from parasites in a gene-for-gene manner and trigger defense responses. we identify avr(a10) and avr(k1) of barley powdery mildew fungus, blumeria grami ...	2006	16905653
characterization of outer membrane vesicles released by the psychrotolerant bacterium pseudoalteromonas antarctica nf3.	pseudoalteromonas antarctica nf3 is an antarctic psychrotolerant gram-negative bacterium that accumulates large amounts of an extracellular polymeric substance (eps) with high protein content. transmission electron microscopy analysis after high-pressure freezing and freeze substitution (hpf-fs) shows that the eps is composed of a capsular polymer and large numbers of outer membrane vesicles (omvs). these vesicles are bilayered structures and predominantly spherical in shape, with an average dia ...	2006	16913913
oxylipin profiling of the hypersensitive response in arabidopsis thaliana. formation of a novel oxo-phytodienoic acid-containing galactolipid, arabidopside e.	oxidation products of unsaturated fatty acids, collectively known as oxylipins, function as signaling molecules in plants during development, wounding, and insect and pathogen attack. certain oxylipins are also known to have direct cytotoxic effects on pathogens. we used inducible expression of bacterial avirulence proteins in planta to study the involvement of oxylipins in race-specific defense against bacterial pathogens. we demonstrate that recognition of the pseudomonas syringae avirulence p ...	2006	16923817
pseudomonas syringae hrpj is a type iii secreted protein that is required for plant pathogenesis, injection of effectors, and secretion of the hrpz1 harpin.	the bacterial plant pathogen pseudomonas syringae requires a type iii protein secretion system (ttss) to cause disease. the p. syringae ttss is encoded by the hrp-hrc gene cluster. one of the genes within this cluster, hrpj, encodes a protein with weak similarity to yopn, a type iii secreted protein from the animal pathogenic yersinia species. here, we show that hrpj is secreted in culture and translocated into plant cells by the p. syringae pv. tomato dc3000 ttss. a dc3000 hrpj mutant, unl140, ...	2006	16923873
evolution of vitamin b2 biosynthesis: 6,7-dimethyl-8-ribityllumazine synthases of brucella.	the penultimate step in the biosynthesis of riboflavin (vitamin b2) involves the condensation of 3,4-dihydroxy-2-butanone 4-phosphate with 5-amino-6-ribitylamino-2,4(1h,3h)-pyrimidinedione, which is catalyzed by 6,7-dimethyl-8-ribityllumazine synthase (lumazine synthase). pathogenic brucella species adapted to an intracellular lifestyle have two genes involved in riboflavin synthesis, ribh1 and ribh2, which are located on different chromosomes. the ribh2 gene was shown previously to specify a lu ...	2006	16923880
phospholipase-dependent signalling during the avrrpm1- and avrrpt2-induced disease resistance responses in arabidopsis thaliana.	bacterial pathogens deliver type iii effector proteins into plant cells during infection. on susceptible host plants, type iii effectors contribute to virulence, but on resistant hosts they betray the pathogen to the plant's immune system and are functionally termed avirulence (avr) proteins. recognition induces a complex suite of cellular and molecular events comprising the plant's inducible defence response. as recognition of type iii effector proteins occurs inside host cells, defence respons ...	2006	16925603
extensive genomic plasticity in pseudomonas aeruginosa revealed by identification and distribution studies of novel genes among clinical isolates.	the distributed genome hypothesis (dgh) states that each strain within a bacterial species receives a unique distribution of genes from a population-based supragenome that is many times larger than the genome of any given strain. the observations that natural infecting populations are often polyclonal and that most chronic bacterial pathogens have highly developed mechanisms for horizontal gene transfer suggested the dgh and provided the means and the mechanisms to explain how chronic infections ...	2006	16926421
comparative analysis of argk-tox clusters and their flanking regions in phaseolotoxin-producing pseudomonas syringae pathovars.	dna fragments containing argk-tox clusters and their flanking regions were cloned from the chromosomes of pseudomonas syringae pathovar (pv.) actinidiae strain kw-11 (act) and p. syringae pv. phaseolicola strain maff 302282 (pha), and then their sequences were determined. comparative analysis of these sequences and the sequences of p. syringae pv. tomato dc3000 (tom) (buell et al., proc natl acad sci usa 100:10181-10186, 2003) and pv. syringae b728a (syr) (feil et al., proc natl acad sci usa 102 ...	2006	16927007
expression and functional roles of the pepper pathogen-induced transcription factor rav1 in bacterial disease resistance, and drought and salt stress tolerance.	a novel pathogen-induced gene encoding the rav (related to abi3/vp1) transcription factor, carav1, was isolated from pepper leaves infected with xanthomonas campestris pv. vesicatoria. carav1 contains two distinct dna-binding domains ap2 and b3 uniquely found in higher plants. transient expression analysis of the smgfp:carav1 fusion construct in arabidopsis protoplasts and pepper epidermal cells revealed the carav1 protein to be localized in the nucleus. the n-terminal region of carav1 fused to ...	2006	16927203
exopolysaccharide-associated protein sorting in environmental organisms: the pep-cterm/epsh system. application of a novel phylogenetic profiling heuristic.	protein translocation to the proper cellular destination may be guided by various classes of sorting signals recognizable in the primary sequence. detection in some genomes, but not others, may reveal sorting system components by comparison of the phylogenetic profile of the class of sorting signal to that of various protein families.	2006	16930487
integrated regulation of the type iii secretion system and other virulence determinants in ralstonia solanacearum.	in many plant and animal bacterial pathogens, the type iii secretion system (ttss) that directly translocates effector proteins into the eukaryotic host cells is essential for the development of disease. in all species studied, the transcription of the ttss and most of its effector substrates is tightly regulated by a succession of consecutively activated regulators. however, the whole genetic programme driven by these regulatory cascades is still unknown, especially in bacterial plant pathogens ...	2006	16933989
dead-box rna helicases in escherichia coli.	in spite of their importance in rna metabolism, the function of dexd/h-box proteins (including dead-box proteins) is poorly understood at the molecular level. here, we present recent progress achieved with the five dead-box proteins from escherichia coli, which have been particularly well studied. these proteins, which have orthologues in many bacteria, participate, in particular, in specific steps of mrna decay and ribosome assembly. in vitro, they behave as poorly processive rna helicases, pre ...	2006	16935881
hormonal and stress induction of the gene encoding common bean acetyl-coenzyme a carboxylase.	regulation of the cytosolic acetyl-coenzyme a carboxylase (accase) gene promoter from common bean (phaseolus vulgaris) was studied in transgenic arabidopsis (arabidopsis thaliana) plants using a beta-glucuronidase (gus) reporter gene fusion (pvaccase::gus). under normal growth conditions, gus was expressed in hydathodes, stipules, trichome bases, flowers, pollen, and embryos. in roots, expression was observed in the tip, elongation zone, hypocotyl-root transition zone, and lateral root primordia ...	2006	16935989
role of ptsp, orft, and sss recombinase genes in root colonization by pseudomonas fluorescens q8r1-96.	pseudomonas fluorescens q8r1-96 produces 2,4-diacetylphloroglucinol (2,4-dapg), a polyketide antibiotic that suppresses a wide variety of soilborne fungal pathogens, including gaeumannomyces graminis var. tritici, which causes take-all disease of wheat. strain q8r1-96 is representative of the d-genotype of 2,4-dapg producers, which are exceptional because of their ability to aggressively colonize and maintain large populations on the roots of host plants, including wheat, pea, and sugar beet. in ...	2006	16936061
transcriptional changes in powdery mildew infected wheat and arabidopsis leaves undergoing syringolin-triggered hypersensitive cell death at infection sites.	blumeria graminis f.sp. tritici, the causal agent of powdery mildew in wheat, is an obligate biotrophic fungus that exclusively invades epidermal cells. as previously shown, spraying of a solution of syringolin a, a circular peptide derivative secreted by the phytopathogenic bacterium pseudomonas syringae pv. syringae, triggers hypersensitive cell death at infection sites in powdery mildew infected wheat. thus, the fungus is essentially eradicated. here we show that syringolin a also triggers hy ...	2006	16941219
genome-wide gene expression analysis of pseudomonas syringae pv. tomato dc3000 reveals overlapping and distinct pathways regulated by hrpl and hrprs.	pseudomonas syringae pv. tomato dc3000 is a model pathogen infecting tomato and arabidopsis plants. genes encoding the type iii secretion system and substrate proteins (collectively called ttss genes) of this bacterium are induced in plants and in minimal medium (mm). the induction of ttss genes is mediated by hrpl, an alternative sigma factor recognizing the hrp box in the promoter of ttss genes. the transcription of hrpl is activated by hrpr and hrps, two homologous dna-binding proteins encode ...	2006	16941902
the type iii effector repertoire of pseudomonas syringae pv. syringae b728a and its role in survival and disease on host and non-host plants.	the bacterial plant pathogen pseudomonas syringae injects a large repertoire of effector proteins into plant cells using a type iii secretion apparatus. effectors can trigger or suppress defences in a host-dependent fashion. host defences are often accompanied by programmed cell death, while interference with defences is sometimes associated with cell death suppression. we previously predicted the effector repertoire of the sequenced bean pathogen p. syringae pv. syringae (psy) b728a using bioin ...	2006	16942603
diversifying selection drives the evolution of the type iii secretion system pilus of pseudomonas syringae.	the plant pathogenic bacterium pseudomonas syringae uses a type iii secretion system to inject virulence proteins directly into the cytoplasm of its hosts. the p. syringae type iii secretion apparatus is encoded, in part, by the hrpz operon, which carries the hrpa gene encoding the pilin subunit of the pilus, various components of the structural apparatus, and the hrpz harpin protein that is believed to produce pores in the host cell membrane. the pilus of the type iii system comes into direct c ...	2006	16950758
characterization of a mitogen-activated protein kinase gene from cucumber required for trichoderma-conferred plant resistance.	the fungal biocontrol agent trichoderma asperellum has been recently shown to induce systemic resistance in plants through a mechanism that employs jasmonic acid and ethylene signal transduction pathways. mitogen-activated protein kinase (mapk) proteins have been implicated in the signal transduction of a wide variety of plant stress responses. here we report the identification and characterization of a trichoderma-induced mapk (tipk) gene function in cucumber (cucumis sativus). similar to its h ...	2006	16950863
comparative genomics of host-specific virulence in pseudomonas syringae.	while much study has gone into characterizing virulence factors that play a general role in disease, less work has been directed at identifying pathogen factors that act in a host-specific manner. understanding these factors will help reveal the variety of mechanisms used by pathogens to suppress or avoid host defenses. we identified candidate pseudomonas syringae host-specific virulence genes by searching for genes whose distribution among natural p. syringae isolates was statistically associat ...	2006	16951068
cawrky2, a chili pepper transcription factor, is rapidly induced by incompatible plant pathogens.	wrky family proteins are a class of plant-specific transcription factors involved in stress response signaling pathways. in this study a gene encoding a putative wrky protein was isolated from a pepper est database (http://genepool.kribb.re.kr). the cdna, named capsicum annuum wrky2 (cawrky2), encodes a putative polypeptide of 548 amino acids, containing two wrky domains with zinc finger motifs and two potential nuclear localization signals. northern blot analyses showed that cawrky2 mrna was pr ...	2006	16951551
identification, typing, and insecticidal activity of xenorhabdus isolates from entomopathogenic nematodes in united kingdom soil and characterization of the xpt toxin loci.	xenorhabdus strains from entomopathogenic nematodes isolated from united kingdom soils by using the insect bait entrapment method were characterized by partial sequencing of the 16s rrna gene, four housekeeping genes (asd, ompr, reca, and serc) and the flagellin gene (flic). most strains (191/197) were found to have genes with greatest similarity to those of xenorhabdus bovienii, and the remaining six strains had genes most similar to those of xenorhabdus nematophila. generally, 16s rrna sequenc ...	2006	16957209
microbial communities in the surface mucopolysaccharide layer and the black band microbial mat of black band-diseased siderastrea siderea.	microbial community profiles and species composition associated with two black band-diseased colonies of the coral siderastrea siderea were studied by 16s rrna-targeted gene cloning, sequencing, and amplicon-length heterogeneity pcr (lh-pcr). bacterial communities associated with the surface mucopolysaccharide layer (sml) of apparently healthy tissues of the infected colonies, together with samples of the black band disease (bbd) infections, were analyzed using the same techniques for comparison ...	2006	16957217
an oxidoreductase is involved in cercosporin degradation by the bacterium xanthomonas campestris pv. zinniae.	the polyketide toxin cercosporin plays a key role in pathogenesis by fungal species of the genus cercospora. the bacterium xanthomonas campestris pv. zinniae is able to rapidly degrade this toxin. growth of x. campestris pv. zinniae strains in cercosporin-containing medium leads to the breakdown of cercosporin and to the formation of xanosporic acid, a nontoxic breakdown product. five non-cercosporin-degrading mutants of a strain that rapidly degrades cercosporin (xcz-3) were generated by ethyl ...	2006	16957231
elucidation of the hrp clusters of xanthomonas oryzae pv. oryzicola that control the hypersensitive response in nonhost tobacco and pathogenicity in susceptible host rice.	xanthomonas oryzae pv. oryzicola, the cause of bacterial leaf streak in rice, possesses clusters of hrp genes that determine its ability to elicit a hypersensitive response (hr) in nonhost tobacco and pathogenicity in host rice. a 27-kb region of the genome of x. oryzae pv. oryzicola (rs105) was identified and sequenced, revealing 10 hrp, 9 hrc (hrp conserved), and 8 hpa (hrp-associated) genes and 7 regulatory plant-inducible promoter boxes. while the region from hpa2 to hpab and the hrpf operon ...	2006	16957248
complete genome sequence of the marine, chemolithoautotrophic, ammonia-oxidizing bacterium nitrosococcus oceani atcc 19707.	the gammaproteobacterium nitrosococcus oceani (atcc 19707) is a gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; g+c content of 50.4%) and a plasmid (40,420 bp) that contain 3,052 and 41 candidate protein-encoding genes, respectively. the genes encoding proteins necessary for the function of known modes of lithotrophy and ...	2006	16957257
pathogen-induced arabidopsis wrky7 is a transcriptional repressor and enhances plant susceptibility to pseudomonas syringae.	the arabidopsis (arabidopsis thaliana) wrky7 gene is induced by pathogen infection and salicylic acid (sa) treatment and may therefore play a role in plant defense responses. here, we show that wrky7 is localized in the nucleus, recognizes dna molecules with the w-box (ttgac) elements, and functions as a transcriptional repressor in plant cells. to study its biological functions directly, we have characterized both loss-of-function t-dna insertion and rnai mutants and gain-of-function transgenic ...	2006	16963526
genetic differences between blight-causing erwinia species with differing host specificities, identified by suppression subtractive hybridization.	pcr-based subtractive hybridization was used to isolate sequences from erwinia amylovora strain ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: e. amylovora mr1, which is pathogenic only on rubus spp.; erwinia pyrifoliae ep1/96, the causal agent of shoot blight of asian pears; and erwinia sp. strain ejp556, the causal agent of bacterial shoot blight of pear in japan. in total, six subtractive libraries were ...	2006	16963554
complete nucleotide sequence of an exogenously isolated plasmid, plb1, involved in gamma-hexachlorocyclohexane degradation.	the alpha-proteobacterial strain sphingobium japonicum ut26 utilizes a highly chlorinated pesticide, gamma-hexachlorocyclohexane (gamma-hch), as a sole source of carbon and energy, and haloalkane dehalogenase linb catalyzes the second step of gamma-hch degradation in ut26. functional complementation of a linb mutant of ut26, ut26db, was performed by the exogenous plasmid isolation technique using hch-contaminated soil, leading to our successful identification of a plasmid, plb1, carrying the lin ...	2006	16963556
eukaryotic cyclophilin as a molecular switch for effector activation.	gram-negative phytopathogenic bacteria, such as pseudomonas syringae, deliver multiple effector proteins into plant cells during infection. it is hypothesized that certain plant and mammalian effector proteins need to traverse the type iii secretion system unfolded and are delivered into host cells as inactive enzymes. we have previously identified cyclophilin as the arabidopsis eukaryotic activator of avrrpt2, a p. syringae effector that is a cysteine protease. cyclophilins are general folding ...	2006	16968222
enhancement of chilling resistance of inoculated grapevine plantlets with a plant growth-promoting rhizobacterium, burkholderia phytofirmans strain psjn.	in vitro inoculation of vitis vinifera l. cv. chardonnay explants with a plant growth-promoting rhizobacterium, burkholderia phytofirmans strain psjn, increased grapevine growth and physiological activity at a low temperature. there was a relationship between endophytic bacterial colonization of the grapevine plantlets and their growth at both ambient (26 degrees c) and low (4 degrees c) temperatures and their sensitivities to chilling. the major benefits of bacterization were observed on root g ...	2006	16980419
colocation of genes encoding a trna-mrna hybrid and a putative signaling peptide on complementary strands in the genome of the hyperthermophilic bacterium thermotoga maritima.	in the genome of the hyperthermophilic bacterium thermotoga maritima, tm0504 encodes a putative signaling peptide implicated in population density-dependent exopolysaccharide formation. although not noted in the original genome annotation, tm0504 was found to colocate, on the opposite strand, with the gene encoding ssra, a hybrid of trna and mrna (tmrna), which is involved in a trans-translation process related to ribosome rescue and is ubiquitous in bacteria. specific dna probes were designed a ...	2006	16980482
ospf and ospc1 are shigella flexneri type iii secretion system effectors that are required for postinvasion aspects of virulence.	shigella flexneri is the causative agent of dysentery, and its pathogenesis is mediated by a type iii secretion system (t3ss). s. flexneri secretes effector proteins into the eukaryotic cell via the t3ss, and these proteins usurp host cellular functions to the benefit of the bacteria. ospf and ospc1 are known to be secreted by s. flexneri, but their functions are unknown. we transformed s. flexneri with a plasmid that expresses a two-hemagglutinin tag (2ha) in frame with ospf or ospc1 and verifi ...	2006	16988276
antimicrobial activity of extracts of chemical races of the lichen pseudevernia furfuracea and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents.	the antimicrobial activity and the mic values of the ethanol, chloroform, diethyl ether, and acetone extracts of the chemical races of pseudevernia furfuracea (var. furfuracea and var. ceratea) and their physodic acid, chloroatranorin, atranorin, and olivetoric acid constituents have been investigated against some microorganisms. nearly all extracts of both chemical races showed antimicrobial activity against aeromonas hydrophila, bacillus cereus, bacillus subtilis, listeria monocytogenes, prote ...	2006	16989308
disruption of n-acyl homoserine lactone-mediated cell signaling and iron acquisition in epiphytic bacteria by leaf surface compounds.	since n-acyl homoserine lactones (ahls) are key mediators of cell density-dependent regulation of traits involved in virulence and epiphytic fitness in gram-negative bacteria such as pseudomonas syringae, a variety of plant species were examined to determine their production of leaf surface compounds that could interact with these signaling systems. leaf washings of 17 of 52 plant species tested stimulated or inhibited ahl-dependent traits in at least one of the bacterial reporter strains used. ...	2006	16997987
the crystal structure of the e. coli stress protein ycif.	ycif is a protein that is up-regulated when bacteria experience stress conditions, and is highly conserved in a range of bacterial species. ycif has no known structure or biochemical function. to learn more about its potential molecular function and its role in the bacterial stress response, we solved the crystal structure of ycif at 2.0 angstrom resolution by the multiple wavelength anomalous diffraction (mad) technique. ycif is a dimer in solution, and forms a homodimer in the crystal asymmetr ...	2006	17001035
resistance of yersinia pestis to antimicrobial agents.		2006	17005799
contribution of alginate and levan production to biofilm formation by pseudomonas syringae.	exopolysaccharides (epss) play important roles in the attachment of bacterial cells to a surface and/or in building and maintaining the three-dimensional, complex structure of bacterial biofilms. to elucidate the spatial distribution and function of the epss levan and alginate during biofilm formation, biofilms of pseudomonas syringae strains with different eps patterns were compared. the mucoid strain pg4180.muc, which produces levan and alginate, and its levan- and/or alginate-deficient deriva ...	2006	17005972
arabidopsis displays centromeric dna hypomethylation and cytological alterations of heterochromatin upon attack by pseudomonas syringae.	plant tissues display major alterations upon the perception of microbial pathogens. changes of cytoplasmic and apoplastic components that sense and transduce plant defenses have been extensively characterized. in contrast, less information is available about modifications affecting the plant nuclear genome under these circumstances. here, we investigated whether the arabidopsis thaliana dna methylation status is altered in tissues responding to the attack of pseudomonas syringae pv. tomato dc300 ...	2006	16776291
the erwinia amylovora avrrpt2ea gene contributes to virulence on pear and avrrpt2ea is recognized by arabidopsis rps2 when expressed in pseudomonas syringae.	the enterobacterium erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. in an attempt to identify genes induced during infection of host plants, we identified and cloned a putative effector gene, avrrpt2ea. the deduced amino-acid sequence of the translated avrrpt2ea protein is homologous to the effector protein avrrpt2 previously reported in pseudomonas syringae pv. tomato. these two proteins share 58% identity (7 ...	2006	16776298
the arabidopsis flavin-dependent monooxygenase fmo1 is an essential component of biologically induced systemic acquired resistance.	upon localized attack by necrotizing pathogens, plants gradually develop increased resistance against subsequent infections at the whole-plant level, a phenomenon known as systemic acquired resistance (sar). to identify genes involved in the establishment of sar, we pursued a strategy that combined gene expression information from microarray data with pathological characterization of selected arabidopsis (arabidopsis thaliana) t-dna insertion lines. a gene that is up-regulated in arabidopsis lea ...	2006	16778014
the pto kinase of tomato, which regulates plant immunity, is repressed by its myristoylated n terminus.	specific recognition of the pseudomonas syringae effector proteins avrpto and avrptob in tomato is mediated by pto kinase resulting in induction of defense responses, including hypersensitive cell death via a signaling pathway requiring the nucleotide-binding leucine-rich repeats protein prf. pto is a myristoylated protein, and n-myristoylation is required for signaling. here we demonstrated a role for n-myristoylation in controlling pto kinase activity. a myristoylated peptide corresponding to ...	2006	16785235
casar82a, a pathogen-induced pepper sar8.2, exhibits an antifungal activity and its overexpression enhances disease resistance and stress tolerance.	pepper sar8.2 gene (casar82a) was previously reported to be locally or systemically induced in pepper plants by biotic and abiotic stresses. in this study, the physiological and molecular functions of the pepper sar8.2 protein in the plant defense responses were investigated by generating arabidopsis transgenic lines overexpressing the casar82a gene. the transgenic arabidopsis plants grew faster than the wild-type plants, indicating that the casar82a gene was involved in plant development. the e ...	2006	16786294
auxin flow in anther filaments is critical for pollen grain development through regulating pollen mitosis.	it was well known that auxin is critical for anther/pollen grain development, however, the clear distribution and detailed effects of auxin during floral development are still unclear. we have shown here that, through analyzing gus activities of arabidopsis lines harboring auxin response elements dr5-gus, auxin was mainly accumulated in the anther during flower stages 10-12. further studies employing the indoleacetic acid-lysine synthetase (iaal) coding gene from pseudomonas syringae subsp. sava ...	2006	16786302
genomic analysis of carbon source metabolism of shewanella oneidensis mr-1: predictions versus experiments.	genomic sequences have been used to find the genetic foundation for carbon source metabolism in shewanella oneidensis mr-1. annotated s. oneidensis mr-1 gene products were examined for their sequence similarity to enzymes participating in pathways for utilization of carbon and energy as described in the biocyc database (http://www.biocyc.org/) or in the primary literature. a picture emerges that relegates five- and six-carbon sugars to minor roles as carbon sources, whereas multiple pathways for ...	2006	16788168
erwinia carotovora subspecies produce duplicate variants of expr, luxr homologs that activate rsma transcription but differ in their interactions with n-acylhomoserine lactone signals.	the n-acylhomoserine lactone (ahl) signaling system comprises a producing system that includes acylhomoserine synthase (ahli, a luxi homolog) and a receptor, generally a luxr homolog. ahl controls exoprotein production in erwinia carotovora and consequently the virulence for plants. in previous studies we showed that expr, a luxr homolog, is an ahl receptor and that it activates transcription of rsma, the gene encoding an rna binding protein which is a global negative regulator of exoproteins an ...	2006	16788181
popf1 and popf2, two proteins secreted by the type iii protein secretion system of ralstonia solanacearum, are translocators belonging to the hrpf/nopx family.	ralstonia solanacearum gmi1000 is a gram-negative plant pathogen which contains an hrp gene cluster which codes for a type iii protein secretion system (ttss). we identified two novel hrp-secreted proteins, called popf1 and popf2, which display similarity to one another and to putative ttss translocators, hrpf and nopx, from xanthomonas spp. and rhizobia, respectively. they also show similarities with ttss translocators of the yopb family from animal-pathogenic bacteria. both popf1 and popf2 bel ...	2006	16788199
type iii secretion-dependent modulation of innate immunity as one of multiple factors regulated by pseudomonas aeruginosa rets.	mutation of rets (rtsm) of pseudomonas aeruginosa strain pa103 reduces its virulence in both ocular and respiratory murine models of infection. in vitro, rets mutants exhibit loss of the exsa-regulated type iii secretion system (ttss), reduced twitching motility, and a decrease in association with, invasion of, and survival within corneal epithelial cells. in addition, transcription of multiple other virulence genes is positively and negatively affected by rets mutation. since our published data ...	2006	16790760
pseudomonas syringae effector avrptob suppresses basal defence in arabidopsis.	the virulence and avirulence activities of members of the pseudomonas syringae hopab family of effectors and avrpto were examined in bean, tomato and arabidopsis. proteins were delivered by the rw60 strain of p. syringae pv. phaseolicola. rw60 causes a hypersensitive reaction (hr) in bean and tomato but is restricted without the hr in arabidopsis. dual avirulence and virulence functions in tomato and bean, respectively, were identified in virppha homologues but only avrptob strongly enhanced vir ...	2006	16792692
construction of a bacterial artificial chromosome library and characterization of hrp/hrc gene cluster of pseudomonas syringae pathovar tagetis lmg5090.	pseudomonas syringae pv. tagetis causes apical chlorosis of several plant species in the asteraceae, including marigold. as a means to facilitate the isolation of pathogenicity genes and to characterize the genome of this bacterium, we have constructed a bacterial artificial chromosome library of p. syringae pv. tagetis strain lmg5090. the library consists of 1,536 clones with insert size ranging from 30 to 160 kb and an average size of 86 kb. based upon colony hybridization, the bac clone 420e2 ...	2006	16799767
quantitative in situ assay of salicylic acid in tobacco leaves using a genetically modified biosensor strain of acinetobacter sp. adp1.	salicylic acid (sa) plays important roles in plants, most notably in the induction of systemic acquired resistance (sar) against pathogens. a non-destructive in situ assay for sa would provide new insights into the functions of sa in sar and other sa-regulated phenomena. we assessed a genetically engineered strain of acinetobacter sp. adp1, which proportionally produces bioluminescence in response to salicylates including sa and methylsalicylate, as a reporter for salicylate accumulation in the ...	2006	16805738
inhibition of plant-pathogenic bacteria by short synthetic cecropin a-melittin hybrid peptides.	short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria erwinia amylovora, pseudomonas syringae, and xanthomonas vesicatoria and compared to the previously described peptide pep3 (wklfkkilkvl-nh(2)). the antimicrobial activity of pep3 and 22 analogues was evaluated in terms of the mic and the 50% effective dose (ed(50)) for growth. peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation we ...	2006	16672470
rhizosphere selection of highly motile phenotypic variants of pseudomonas fluorescens with enhanced competitive colonization ability.	phenotypic variants of pseudomonas fluorescens f113 showing a translucent and diffuse colony morphology show enhanced colonization of the alfalfa rhizosphere. we have previously shown that in the biocontrol agent p. fluorescens f113, phenotypic variation is mediated by the activity of two site-specific recombinases, sss and xerd. by overexpressing the genes encoding either of the recombinases, we have now generated a large number of variants (mutants) after selection either by prolonged laborato ...	2006	16672487
proteomic analysis of extracellular proteins from aspergillus oryzae grown under submerged and solid-state culture conditions.	filamentous fungi are widely used for the production of homologous and heterologous proteins. recently, there has been increasing interest in aspergillus oryzae because of its ability to produce heterologous proteins in solid-state culture. to provide an overview of protein secretion by a. oryzae in solid-state culture, we carried out a comparative proteome analysis of extracellular proteins in solid-state and submerged (liquid) cultures. extracellular proteins prepared from both cultures sequen ...	2006	16672490
genetic population structure of the soil bacterium myxococcus xanthus at the centimeter scale.	myxococcus xanthus is a gram-negative soil bacterium best known for its remarkable life history of social swarming, social predation, and multicellular fruiting body formation. very little is known about genetic diversity within this species or how social strategies might vary among neighboring strains at small spatial scales. to investigate the small-scale population structure of m. xanthus, 78 clones were isolated from a patch of soil (16 by 16 cm) in tübingen, germany. among these isolates, 2 ...	2006	16672510
characterization of the yersinia enterocolitica type iii secretion atpase yscn and its regulator, yscl.	type iii secretion is a mechanism used by a broad range of gram-negative bacteria to neutralize eukaryotic defenses by enabling translocation of bacterial proteins directly into the cytoplasm of host cells. the bacterial energy source for secretion is atp, which is consumed by an atpase that couples atp hydrolysis to the unfolding of secreted proteins and the dissociation of their chaperones just prior to secretion. by studying the biochemical properties of yscn and yscl of yersinia enterocoliti ...	2006	16672607
the ornibactin biosynthesis and transport genes of burkholderia cenocepacia are regulated by an extracytoplasmic function sigma factor which is a part of the fur regulon.	burkholderia cenocepacia mutants that fail to produce the siderophore ornibactin were obtained following mutagenesis with mini-tn5tp. these mutants were shown to be growth restricted under conditions of iron depletion. in eight of the mutants, the transposon had integrated into one of two genes, orbi and orbj, encoding nonribosomal peptide synthetases. in the other mutant, the transposon had inserted into an open reading frame, orbs, located upstream from orbi. the polypeptide product of orbs ex ...	2006	16672617
flavonoid-inducible modifications to rhamnan o antigens are necessary for rhizobium sp. strain ngr234-legume symbioses.	rhizobium sp. strain ngr234 produces a flavonoid-inducible rhamnose-rich lipopolysaccharide (lps) that is important for the nodulation of legumes. many of the genes encoding the rhamnan part of the molecule lie between 87 degrees and 110 degrees of pngr234a, the symbiotic plasmid of ngr234. computational methods suggest that 5 of the 12 open reading frames (orfs) within this arc are involved in synthesis (and subsequent polymerization) of l-rhamnose. two others probably play roles in the transpo ...	2006	16672619
chemotaxis is required for virulence and competitive fitness of the bacterial wilt pathogen ralstonia solanacearum.	ralstonia solanacearum, a soilborne plant pathogen of considerable economic importance, invades host plant roots from the soil. qualitative and quantitative chemotaxis assays revealed that this bacterium is specifically attracted to diverse amino acids and organic acids, and especially to root exudates from the host plant tomato. exudates from rice, a nonhost plant, were less attractive. eight different strains from this heterogeneous species complex varied significantly in their attraction to a ...	2006	16672623
avrb mutants lose both virulence and avirulence activities on soybean and arabidopsis.	the pseudomonas syringae pv. glycinea effector protein avrb induces resistance responses in soybean varieties that contain the resistance gene rpg1-b and arabidopsis varieties that carry rpm1. in addition to this avirulence activity, avrb also enhances bacterial virulence on soybean plants that lack rpg1-b and induces a chlorotic phenotype on arabidopsis plants that lack rpm1. we screened a library of avrb mutants for loss of avirulence on soybean and arabidopsis, and assayed selected avirulence ...	2006	16677306
specific bacterial suppressors of mamp signaling upstream of mapkkk in arabidopsis innate immunity.	plants and animals possess innate immune systems to prevent infections and are effectively "nonhosts" for most potential pathogens. the molecular mechanisms underlying nonhost immunity in plants remain obscure. in arabidopsis, nonhost/nonpathogenic pseudomonas syringae sustains but pathogenic p. syringae suppresses early mamp (microbe-associated molecular pattern) marker-gene activation. we performed a cell-based genetic screen of virulence factors and identified avrpto and avrptob as potent and ...	2006	16678099
identification of glycosylation genes and glycosylated amino acids of flagellin in pseudomonas syringae pv. tabaci.	a glycosylation island is a genetic region required for glycosylation. the glycosylation island of flagellin in pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, deltaorf1 and deltaorf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from delta ...	2006	16681835
gene involved in transcriptional activation of the hrp regulatory gene hrpg in xanthomonas oryzae pv. oryzae.	a novel regulatory gene, trh, which is involved in hrp gene expression, is identified in the plant pathogen xanthomonas oryzae pv. oryzae. in the trh mutant, expression of hrpg, which is a key regulator for hrp gene expression, is reduced both under the in vitro hrp-inducing condition and in planta.	2006	16707710
altering glucosinolate profiles modulates disease resistance in plants.	plant diseases are major contributing factors for crop loss in agriculture. here, we show that arabidopsis plants with high levels of novel glucosinolates (gss) as a result of the introduction of single cyp79 genes exhibit altered disease resistance. arabidopsis expressing cyp79d2 from cassava accumulated aliphatic isopropyl and methylpropyl gs, and showed enhanced resistance against the bacterial soft-rot pathogen erwinia carotovora, whereas arabidopsis expressing the sorghum cyp79a1 or over-ex ...	2006	16709192
functional roles of the pepper pathogen-induced bzip transcription factor, cabzip1, in enhanced resistance to pathogen infection and environmental stresses.	transcription factors often belong to multigene families and their individual contribution in a particular regulatory network remains difficult to assess. we identify and functionally characterize the pepper bzip transcription factor cabzip1 gene isolated from pepper leaves infected with xanthomonas campestris pv. vesicatoria. transient expression analysis of the cabzip1-gfp fusion protein in arabidopsis protoplasts revealed that the cabzip1 protein is localized in the nucleus. the n-terminal re ...	2006	16718483
isolation of a novel abc-transporter gene from soybean induced by salicylic acid.	this paper reports on the identification and characterization of a new atp-binding cassette (abc) transporter which was identified as a salicylic acid-induced gene from soybean (glycine max cv. williams 82) in a subtractive suppression hybridization approach. a fragment of an abc-transporter gene was used to isolate a full-length cdna clone for this gene with a length of 4750 bp. the encoded protein has a length of 1447 amino acids and is composed of two similar repeat units typical of full-size ...	2006	16720608