Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| characterization and functional identification of a novel plant 4,5-extradiol dioxygenase involved in betalain pigment biosynthesis in portulaca grandiflora. | betalains are pigments that replace anthocyanins in the majority of families of the plant order caryophyllales. betalamic acid is the common chromophore of betalains. the key enzyme of the betalain biosynthetic pathway is an extradiol dioxygenase that opens the cyclic ring of dihydroxy-phenylalanine (dopa) between carbons 4 and 5, thus producing an unstable seco-dopa that rearranges nonenzymatically to betalamic acid. a gene for a 4,5-dopa-dioxygenase has already been isolated from the fungus am ... | 2004 | 14730069 |
| divergent roles in arabidopsis thaliana development and defense of two homologous genes, aberrant growth and death2 and agd2-like defense response protein1, encoding novel aminotransferases. | the disease-resistant arabidopsis thaliana aberrant growth and death2 (agd2-1) mutant has elevated levels of the defense signal salicylic acid (sa), altered leaf morphology, and mild dwarfism. agd2 and its close homolog ald1 (for agd2-like defense response protein1) encode aminotransferases that act on an overlapping set of amino acids in vitro. however, kinetic parameters indicate that agd2 and ald1 may drive the aminotransferase reaction in opposite directions. ald1-deficient mutants have the ... | 2004 | 14729919 |
| the arabidopsis thaliana dihydroxyacetone phosphate reductase gene suppresssor of fatty acid desaturase deficiency1 is required for glycerolipid metabolism and for the activation of systemic acquired resistance. | systemic acquired resistance (sar) is a broad-spectrum resistance mechanism in plants that is activated in naive organs after exposure of another organ to a necrotizing pathogen. the organs manifesting sar exhibit an increase in levels of salicylic acid (sa) and expression of the pathogenesis-related1 (pr1) gene. sa signaling is required for the manifestation of sar. we demonstrate here that the arabidopsis thaliana suppressor of fatty acid desaturase deficiency1 (sfd1) mutation compromises the ... | 2004 | 14729910 |
| direct glutaminyl-trna biosynthesis and indirect asparaginyl-trna biosynthesis in pseudomonas aeruginosa pao1. | the genomic sequence of pseudomonas aeruginosa pao1 was searched for the presence of open reading frames (orfs) encoding enzymes potentially involved in the formation of gln-trna and of asn-trna. we found orfs similar to known glutamyl-trna synthetases (glurs), glutaminyl-trna synthetases (glnrs), aspartyl-trna synthetases (asprs), and trimeric trna-dependent amidotransferases (adt) but none similar to known asparaginyl-trna synthetases (asnrs). the absence of asnrs was confirmed by biochemical ... | 2004 | 14729703 |
| the nifl-nifa system: a multidomain transcriptional regulatory complex that integrates environmental signals. | 2004 | 14729684 | |
| pathogenicity islands in bacterial pathogenesis. | in this review, we focus on a group of mobile genetic elements designated pathogenicity islands (pai). these elements play a pivotal role in the virulence of bacterial pathogens of humans and are also essential for virulence in pathogens of animals and plants. characteristic molecular features of pai of important human pathogens and their role in pathogenesis are described. the availability of a large number of genome sequences of pathogenic bacteria and their benign relatives currently offers a ... | 2004 | 14726454 |
| efficiency of procedures for induction and cultivation of pseudomonas syringae pv. pisi l-form. | the l-form of pseudomonas syringae pv. phaseolicola has been proved to induce resistance to bean halo blight. various procedures were tested to induce the l-form of pseudomonas syringae pv. pisi for its potential use as biocontrol agent of pea bacterial blight. cell-wall deficient cells were induced in a liquid medium with penicillin following a protocol described for p. s. pv. phaseolicola. cell growth on solid induction medium developed as typical granular and vacuolated structures, and charac ... | 2003 | 14717447 |
| the hcrvf2 gene from a wild apple confers scab resistance to a transgenic cultivated variety. | the vf gene from the wild species malus floribunda 821 is the most studied apple scab resistance gene. several molecular markers mapping around this gene were the starting point for a positional cloning project. the analysis of the bacterial artificial chromosome clones spanning the vf region led to the identification of a cluster of genes homologous to the cladosporium fulvum resistance gene family of tomato. one of these genes, hcrvf2 (homologue of the c. fulvum resistance genes of the vf regi ... | 2004 | 14715897 |
| functional analysis of genes involved in the synthesis of syringolin a by pseudomonas syringae pv. syringae b301 d-r. | strains of the phytopathogenic bacterium pseudomonas syringae pv. syringae secrete a family of structurally closely related peptide derivatives dubbed syringolins, of which syringolin a is the major variant. the function of syringolins in the interaction of p. syringae pv. syringae with their host plants presently is unknown. it is hypothesized that they may constitute virulence factors. however, syringolins are determinants recognized and reacted to by nonhost plant species, and syringolin a ha ... | 2004 | 14714872 |
| rme1 is necessary for mi-1-mediated resistance and acts early in the resistance pathway. | the tomato gene mi-1 confers resistance to root-knot nematodes (meloidogyne spp.), potato aphid, and whitefly. using genetic screens, we have isolated a mutant, rme1 (resistance to meloidogyne spp.), compromised in resistance to m. javanica and potato aphid. here, we show that the rme1 mutant is also compromised in resistance to m. incognita, m. arenaria, and whitefly. in addition, using an agrobacterium-mediated transient assay in leaves to express constitutive gain-of-function mutant pto(l205d ... | 2004 | 14714868 |
| growth of escherichia coli coexpressing phosphotriesterase and glycerophosphodiester phosphodiesterase, using paraoxon as the sole phosphorus source. | phosphotriesterases catalyze the hydrolytic detoxification of phosphotriester pesticides and chemical warfare nerve agents with various efficiencies. the directed evolution of phosphotriesterases to enhance the breakdown of poor substrates is desirable for the purposes of bioremediation. a limiting factor in the identification of phosphotriesterase mutants with increased activity is the ability to effectively screen large mutant libraries. to this end, we have investigated the possibility of cou ... | 2004 | 14711669 |
| frequency, size, and localization of bacterial aggregates on bean leaf surfaces. | using epifluorescence microscopy and image analysis, we have quantitatively described the frequency, size, and spatial distribution of bacterial aggregates on leaf surfaces of greenhouse-grown bean plants inoculated with the plant-pathogenic bacterium pseudomonas syringae pv. syringae strain b728a. bacterial cells were not randomly distributed on the leaf surface but occurred in a wide range of cluster sizes, ranging from single cells to over 10(4) cells per aggregate. the average cluster size i ... | 2004 | 14711662 |
| functional display of foreign protein on surface of escherichia coli using n-terminal domain of ice nucleation protein. | we investigated the ability of the n-terminal domain of inak, an ice nucleation protein from pseudomonas syringae kctc1832, to act as an anchoring motif for the display of foreign proteins on the escherichia coli cell surface. total expression level and surface display efficiency of green fluorescent protein (gfp) was compared following their fusion with either the n-terminal domain of inak (inak-n), or with the known truncated inak containing both n- and c-terminal domains (inak-nc). we report ... | 2004 | 14705004 |
| pseudomonas syringae type iii secretion system targeting signals and novel effectors studied with a cya translocation reporter. | pseudomonas syringae pv. tomato strain dc3000 is a pathogen of tomato and arabidopsis: the hrp-hrc-encoded type iii secretion system (ttss), which injects bacterial effector proteins (primarily called hop or avr proteins) into plant cells, is required for pathogenicity. in addition to being regulated by the hrpl alternative sigma factor, most avr or hop genes encode proteins with n termini that have several characteristic features, including (i) a high percentage of ser residues, (ii) an aliphat ... | 2004 | 14702323 |
| sequence analysis of the mobile genome island pklc102 of pseudomonas aeruginosa c. | the pseudomonas aeruginosa plasmid pklc102 coexists as a plasmid and a genome island in clone c strains. whereas the related plasmid pklk106 reversibly recombines with p. aeruginosa clone k chromosomes at one of the two trna(lys) genes, pklc102 is incorporated into the trna(lys) gene only close to the pila locus. targeting of the other trna(lys) copy in the chromosome is blocked by a 23,395-bp mosaic of truncated pao open reading frames, transposons, and pklc102 homologs. annotation and phylogen ... | 2004 | 14702321 |
| the hwe histidine kinases, a new family of bacterial two-component sensor kinases with potentially diverse roles in environmental signaling. | two-component signal transduction pathways play a major role in the response of bacteria to external cues. these pathways are initiated by large collection of histidine kinases (hks) containing a sensor domain that perceives the environmental signal followed by an hk domain that triggers a histidine-aspartate phosphorelay. previous phylogenetic analyses identified 11 major families of two-component hks by comparing signature motifs within the hk domain. here we describe a new family with homolog ... | 2004 | 14702314 |
| complete sequence and evolutionary genomic analysis of the pseudomonas aeruginosa transposable bacteriophage d3112. | bacteriophage d3112 represents one of two distinct groups of transposable phage found in the clinically relevant, opportunistic pathogen pseudomonas aeruginosa. to further our understanding of transposable phage in p. aeruginosa, we have sequenced the complete genome of d3112. the genome is 37,611 bp, with an overall g+c content of 65%. we have identified 53 potential open reading frames, including three genes (the c repressor gene and early genes a and b) that have been previously characterized ... | 2004 | 14702309 |
| synthesis of the pentasaccharide repeating unit of the major o-antigen component from pseudomonas syringae pv. ribicola nvppb 1010. | the synthesis of the repeating unit of the major o-antigen component from pseudomonas syringae pv. ribicola nvppb 1010 is reported. the strategy used was based on the successive coupling of a trisaccharide rhamnosyl trichloroacetimidate with a rhamnosyl acceptor with a free hydroxyl group on c-2. the pentasaccharide was then obtained by coupling with a n-troc-tri-o-acetyl-glucosamine trichloroacetimidate. the synthesis allowed the oligomerisation of the repeating unit. | 2004 | 14698898 |
| structure of hrcqb-c, a conserved component of the bacterial type iii secretion systems. | type iii secretion systems enable plant and animal bacterial pathogens to deliver virulence proteins into the cytosol of eukaryotic host cells, causing a broad spectrum of diseases including bacteremia, septicemia, typhoid fever, and bubonic plague in mammals, and localized lesions, systemic wilting, and blights in plants. in addition, type iii secretion systems are also required for biogenesis of the bacterial flagellum. the hrcq(b) protein, a component of the secretion apparatus of pseudomonas ... | 2004 | 14694203 |
| structure of hrcqb-c, a conserved component of the bacterial type iii secretion systems. | type iii secretion systems enable plant and animal bacterial pathogens to deliver virulence proteins into the cytosol of eukaryotic host cells, causing a broad spectrum of diseases including bacteremia, septicemia, typhoid fever, and bubonic plague in mammals, and localized lesions, systemic wilting, and blights in plants. in addition, type iii secretion systems are also required for biogenesis of the bacterial flagellum. the hrcq(b) protein, a component of the secretion apparatus of pseudomonas ... | 2004 | 14694203 |
| the crystal structure of pseudomonas avirulence protein avrpphb: a papain-like fold with a distinct substrate-binding site. | avrpphb is an avirulence (avr) protein from the plant pathogen pseudomonas syringae that can trigger a disease-resistance response in a number of host plants including arabidopsis. avrpphb belongs to a novel family of cysteine proteases with the charter member of this family being the yersinia effector protein yopt. avrpphb has a very stringent substrate specificity, catalyzing a single proteolytic cleavage in the arabidopsis serine/threonine kinase pbs1. we have determined the crystal structure ... | 2004 | 14694194 |
| the crystal structure of pseudomonas avirulence protein avrpphb: a papain-like fold with a distinct substrate-binding site. | avrpphb is an avirulence (avr) protein from the plant pathogen pseudomonas syringae that can trigger a disease-resistance response in a number of host plants including arabidopsis. avrpphb belongs to a novel family of cysteine proteases with the charter member of this family being the yersinia effector protein yopt. avrpphb has a very stringent substrate specificity, catalyzing a single proteolytic cleavage in the arabidopsis serine/threonine kinase pbs1. we have determined the crystal structure ... | 2004 | 14694194 |
| the tomato homolog of coronatine-insensitive1 is required for the maternal control of seed maturation, jasmonate-signaled defense responses, and glandular trichome development. | jasmonic acid (ja) is a fatty acid-derived signaling molecule that regulates a broad range of plant defense responses against herbivores and some microbial pathogens. molecular genetic studies in arabidopsis have established that ja also performs a critical role in anther and pollen development but is not essential for other developmental aspects of the plant's life cycle. here, we describe the phenotypic and molecular characterization of a sterile mutant of tomato (jasmonic acid-insensitive1 [j ... | 2004 | 14688297 |
| plant er genes that encode photorespiratory enzymes confer resistance against disease. | downy mildew caused by the oomycete pathogen pseudoperonospora cubensis is a devastating foliar disease of cucurbits worldwide. we previously demonstrated that the wild melon line pi 124111f (pi) is highly resistant to all pathotypes of p. cubensis. that resistance was controlled genetically by two partially dominant, complementary loci. here, we show that unlike other plant disease resistance genes, which confer an ability to resist infection by pathogens expressing corresponding avirulence gen ... | 2004 | 14688292 |
| inhibitory effects of phaseolotoxin on proliferation of leukemia cells hl-60, k-562 and l1210 and pancreatic cells rin-m5f. | phaseolotoxin (pt) is a non-host specific phytotoxin produced by the plant pathogenic bacterium pseudomonas syringae (p.s.) pv. phaseolicola. in the present study, the inhibitory effect of pt on the proliferation of leukemia cells was studied. after 4 days of treatment, pt decreased cell growth of leukemia cell lines hl-60, k-562 and l1210 in a dose-dependent manner. in addition, pt also reduced cell growth of the insulinoma pancreatic cell line rin-m5f. ic50 values were 2.1 +/- 1.0 microm (hl-6 ... | 2004 | 14687626 |
| induction of 3'-o-beta-d-ribofuranosyl adenosine during compatible, but not during incompatible, interactions of arabidopsis thaliana or lycopersicon esculentum with pseudomonas syringae pathovar tomato. | all hitherto identified aromatic compounds accumulating in leaves of arabidopsis thaliana (l.) heynh. upon infection with virulent or avirulent strains of pseudomonas syringae pathovar tomato ( pst) were indolic metabolites. we now report the strong accumulation of a novel type of natural product, 3'-o-beta-d-ribofuranosyl adenosine (3'ra), exclusively during compatible interactions. in contrast to the various indolic metabolites, 3'ra was undetectable in incompatible interactions of a. thaliana ... | 2004 | 14685856 |
| biocontrol of bacillus subtilis against infection of arabidopsis roots by pseudomonas syringae is facilitated by biofilm formation and surfactin production. | relatively little is known about the exact mechanisms used by bacillus subtilis in its behavior as a biocontrol agent on plants. here, we report the development of a sensitive plant infection model demonstrating that the bacterial pathogen pseudomonas syringae pv tomato dc3000 is capable of infecting arabidopsis roots both in vitro and in soil. using this infection model, we demonstrated the biocontrol ability of a wild-type b. subtilis strain 6051 against p. syringae. arabidopsis root surfaces ... | 2004 | 14684838 |
| expression of l-ornithine ndelta-oxygenase (pvda) in fluorescent pseudomonas species: an immunochemical and in silico study. | omega-amino acid monooxygenases (ec 1.14.13.-), catalysing the formation of hydroxamate precursors of microbial siderophores (e.g., pyoverdine), have so far eluded structural and biochemical characterisation. here, the expression of recombinant l-ornithine-ndelta-oxygenase (pvda) from pseudomonas aeruginosa pao1 is reported. a library of eight monoclonal antibodies (mabs) directed against pvda has been generated. two mab families recognising the n- and c-terminal regions of pvda were identified. ... | 2004 | 14684153 |
| photosynthetic acclimation is reflected in specific patterns of gene expression in drought-stressed loblolly pine. | because the product of a single gene can influence many aspects of plant growth and development, it is necessary to understand how gene products act in concert and upon each other to effect adaptive changes to stressful conditions. we conducted experiments to improve our understanding of the responses of loblolly pine (pinus taeda) to drought stress. water was withheld from rooted plantlets of to a measured water potential of -1 mpa for mild stress and -1.5 mpa for severe stress. net photosynthe ... | 2003 | 14681533 |
| the insecticidal toxin makes caterpillars floppy 2 (mcf2) shows similarity to hrma, an avirulence protein from a plant pathogen. | the photorhabdus luminescens w14 toxin encoding gene makes caterpillars floppy (mcf) was discovered due to its ability to kill caterpillars when expressed in escherichia coli. here we describe a homologue of mcf (renamed as mcf1), termed mcf2, discovered in the same genome. the mcf2 gene predicts another large toxin whose central domain, like mcf1, also shows limited homology to clostridium cytotoxin b. however, the n-terminus of mcf2 shows significant similarity to the type-iii secreted effecto ... | 2003 | 14680709 |
| in pseudomonas syringae pv. phaseolicola, expression of the argk gene, encoding the phaseolotoxin-resistant ornithine carbamoyltransferase, is regulated indirectly by temperature and directly by a precursor resembling carbamoylphosphate. | pseudomonas syringae pv. phaseolicola synthesizes a non-host-specific toxin, phaseolotoxin, and also synthesizes a phaseolotoxin-resistant ornithine carbamoyltransferase (roct) to protect itself from its own toxin. roct is encoded by argk, which is expressed coordinately with phaseolotoxin synthesis at 18 degrees c. to investigate the regulatory mechanisms of this system, null mutants were constructed for argk, argf (encoding the phaseolotoxin-sensitive octase [soct]), and amta (encoding an amid ... | 2004 | 14679234 |
| rtsa coordinately regulates dsba and the salmonella pathogenicity island 1 type iii secretion system. | salmonella serovars cause a wide variety of diseases ranging from mild gastroenteritis to life-threatening systemic infections. an important step in salmonella enterica serovar typhimurium infection is the invasion of nonphagocytic epithelial cells, mediated by a type iii secretion system (ttss) encoded on salmonella pathogenicity island 1 (spi1). the spi1 ttss forms a needle complex through which effector proteins are injected into the cytosol of host cells, where they promote actin rearrangeme ... | 2004 | 14679226 |
| characterization of cmaa, an adenylation-thiolation didomain enzyme involved in the biosynthesis of coronatine. | several pathovars of pseudomonas syringae produce the phytotoxin coronatine (cor), which contains an unusual amino acid, the 1-amino-2-ethylcyclopropane carboxylic acid called coronamic acid (cma), which is covalently linked to a polyketide-derived carboxylic acid, coronafacic acid, by an amide bond. the region of the cor biosynthetic gene cluster proposed to be responsible for cma biosynthesis was resequenced, and errors in previously deposited cmaa sequences were corrected. these efforts allow ... | 2004 | 14679222 |
| influence of growth temperature on lipid and phosphate contents of surface polysaccharides from the antarctic bacterium pseudoalteromonas haloplanktis tac 125. | the chemical structural variations induced by different growth temperatures in the lipooligosaccharide and exopolysaccharide components extracted from the antarctic bacterium pseudoalteromonas haloplanktis tac 125 are described. the increase in phosphorylation with the increase in growth temperature seems to be general, because it happens not only for the lipooligosaccharide but also for the exopolysaccharide. structural variations in the lipid components of lipid a also occur. in addition, free ... | 2004 | 14679221 |
| two mapk cascades, npr1, and tga transcription factors play a role in pto-mediated disease resistance in tomato. | the tomato pto kinase confers resistance to the causative agent of bacterial speck disease, pseudomonas syringae pv. tomato, by recognizing the pathogen effector proteins avrpto or avrptob. pto-mediated resistance requires multiple signal transduction pathways and has been shown to activate many defense responses including an oxidative burst, rapid changes in the expression of over 400 genes, and localized cell death. we have tested the role in pto-mediated resistance in tomato of a set of 21 ge ... | 2003 | 14675454 |
| signals for local and systemic responses of plants to pathogen attack. | activation of plant defences following recognition of pathogen attack involves complex reiterative signal networks with extensive signal amplification and cross-talk. the results of two approaches that have been taken to analyse signalling in plant-microbe interactions are discussed here. activation tagging with t-dna harbouring multiple 35s enhancer elements was employed as a gain-of-function approach to dissect signalling related to bacterial pathogen resistance in arabidopsis thaliana. from a ... | 2004 | 14673031 |
| differential survival of solitary and aggregated bacterial cells promotes aggregate formation on leaf surfaces. | the survival of individual pseudomonas syringae cells was determined on bean leaf surfaces maintained under humid conditions or periodically exposed to desiccation stress. cells of p. syringae strain b728a harboring a gfp marker gene were visualized by epifluorescence microscopy, either directly in situ or after recovery from leaves, and dead cells were identified as those that were stained with propidium iodide in such populations. under moist, conducive conditions on plants, the proportion of ... | 2003 | 14665692 |
| molecular basis of bacterial outer membrane permeability revisited. | gram-negative bacteria characteristically are surrounded by an additional membrane layer, the outer membrane. although outer membrane components often play important roles in the interaction of symbiotic or pathogenic bacteria with their host organisms, the major role of this membrane must usually be to serve as a permeability barrier to prevent the entry of noxious compounds and at the same time to allow the influx of nutrient molecules. this review summarizes the development in the field since ... | 2003 | 14665678 |
| concomitant induction of systemic resistance to pseudomonas syringae pv. lachrymans in cucumber by trichoderma asperellum (t-203) and accumulation of phytoalexins. | most studies on the reduction of disease incidence in soil treated with trichoderma asperellum have focused on microbial interactions rather than on plant responses. this study presents conclusive evidence for the induction of a systemic response against angular leaf spot of cucumber (pseudomonas syringae pv. lachrymans) following application of t. asperellum to the root system. to ascertain that t. asperellum was the only microorganism present in the root milieu, plants were grown in an aseptic ... | 2003 | 14660384 |
| metagenome survey of biofilms in drinking-water networks. | most naturally occurring biofilms contain a vast majority of microorganisms which have not yet been cultured, and therefore we have little information on the genetic information content of these communities. therefore, we initiated work to characterize the complex metagenome of model drinking water biofilms grown on rubber-coated valves by employing three different strategies. first, a sequence analysis of 650 16s rrna clones indicated a high diversity within the biofilm communities, with the ma ... | 2003 | 14660379 |
| characterization of the arga gene required for arginine biosynthesis and syringomycin production by pseudomonas syringae pv. syringae. | two types of necrosis-inducing lipodepsipeptide toxins, called syringomycin and syringopeptin, are major virulence factors of pseudomonas syringae pv. syringae strain b301d. a previous study showed that a locus, called syra, was required for both syringomycin production and plant pathogenicity, and the syra locus was speculated to encode a regulator of toxin production. in this study, sequence analysis of the 8-kb genomic dna fragment that complements the syra phenotype revealed high conservatio ... | 2003 | 14660376 |
| biochemical, genetic, and zoosporicidal properties of cyclic lipopeptide surfactants produced by pseudomonas fluorescens. | zoospores play an important role in the infection of plant and animal hosts by oomycetes and other zoosporic fungi. in this study, six fluorescent pseudomonas isolates with zoosporicidal activities were obtained from the wheat rhizosphere. zoospores of multiple oomycetes, including pythium species, albugo candida, and phytophthora infestans, were rendered immotile within 30 s of exposure to cell suspensions or cell culture supernatants of the six isolates, and subsequent lysis occurred within 60 ... | 2003 | 14660362 |
| efficient degradation of 2,4,6-trichlorophenol requires a set of catabolic genes related to tcp genes from ralstonia eutropha jmp134(pjp4). | 2,4,6-trichlorophenol (2,4,6-tcp) is a hazardous pollutant. several aerobic bacteria are known to degrade this compound. one of these, ralstonia eutropha jmp134(pjp4), a well-known, versatile chloroaromatic compound degrader, is able to grow in 2,4,6-tcp by converting it to 2,6-dichlorohydroquinone, 6-chlorohydroxyquinol, 2-chloromaleylacetate, maleylacetate, and beta-ketoadipate. three enzyme activities encoded by tcp genes, 2,4,6-tcp monooxygenase (tcpa), 6-chlorohydroxyquinol 1,2-dioxygenase ... | 2003 | 14660355 |
| new connections in the prokaryotic toxin-antitoxin network: relationship with the eukaryotic nonsense-mediated rna decay system. | several prokaryotic plasmids maintain themselves in their hosts by means of diverse post-segregational cell killing systems. recent findings suggest that chromosomally encoded copies of toxins and antitoxins of post-segregational cell killing systems - such as the rele system - might function as regulatory switches under stress conditions. the rele toxin cleaves ribosome-associated transcripts, whereas another post-segregational cell killing toxin, pare, functions as a gyrase inhibitor. | 2003 | 14659018 |
| induction of salt and osmotic stress tolerance by overexpression of an intracellular vesicle trafficking protein atrab7 (atrabg3e). | adaptation to stress requires removal of existing molecules from various cellular compartments and replacing them with new ones. the transport of materials to and from the specific compartments involved in the recycling and deposition of macromolecules is carried out by an intracellular vesicle trafficking system. here, we report the isolation of a vesicle trafficking-regulating gene, atrabg3e (formerly atrab7), from arabidopsis. the gene was induced during programmed cell death after treatment ... | 2004 | 14657401 |
| gaca, the response regulator of a two-component system, acts as a master regulator in pseudomonas syringae pv. tomato dc3000 by controlling regulatory rna, transcriptional activators, and alternate sigma factors. | concerted investigations of factors affecting host-pathogen interactions are now possible with the model plant arabidopsis thaliana and its model pathogen pseudomonas syringae pv. tomato dc3000, as their whole genome sequences have become available. as a prelude to analysis of the regulatory genes and their targets, we have focused on gaca, the response regulator of a two-component system. the dc3000 gene was cloned by testing for the reversal of phenotypes of an erwinia gaca- mutant. a gaca- mu ... | 2003 | 14651344 |
| pathways leading from bara/sira to motility and virulence gene expression in salmonella. | the bara and sira genes of salmonella enterica serovar typhimurium encode a two-component sensor kinase and a response regulator, respectively. this system increases the expression of virulence genes and decreases the expression of motility genes. in this study, we examined the pathways by which sira affects these genes. we found that the master regulator of flagellar genes, flhdc, had a positive regulatory effect on the primary regulator of intestinal virulence determinants, hila, but that hila ... | 2003 | 14645287 |
| xopc and xopj, two novel type iii effector proteins from xanthomonas campestris pv. vesicatoria. | pathogenicity of the gram-negative plant pathogen xanthomonas campestris pv. vesicatoria depends on a type iii secretion (tts) system which translocates bacterial effector proteins into the plant cell. previous transcriptome analysis identified a genome-wide regulon of putative virulence genes that are coexpressed with the tts system. in this study, we characterized two of these genes, xopc and xopj. both genes encode xanthomonas outer proteins (xops) that were shown to be secreted by the tts sy ... | 2003 | 14645268 |
| a dna element recognised by the molybdenum-responsive transcription factor mode is conserved in proteobacteria, green sulphur bacteria and archaea. | the transition metal molybdenum is essential for life. escherichia coli imports this metal into the cell in the form of molybdate ions, which are taken up via an abc transport system. in e. coli and other proteobacteria molybdenum metabolism and homeostasis are regulated by the molybdate-responsive transcription factor mode. | 2003 | 14641908 |
| complete nucleotide sequence and analysis of ppsr1 (72,601 bp), a ppt23a-family plasmid from pseudomonas syringae pv. syringae a2. | plasmid ppsr1 is a conjugative plasmid originally isolated from pseudomonas syringae pv. syringae a2, and is a member of the recently described ppt23a plasmid family. we have determined the complete sequence of ppsr1 and found the plasmid to be 72,601 bp in length, encoding 55 orfs. putative functions were assigned to 49 orfs; of these, 24 (49.0%) are involved in plasmid replication, maintenance or conjugation, 17 (34.7%) have roles in virulence or ecological fitness, and eight (16.3%) encode tr ... | 2004 | 14634868 |
| the tomato transcription factor pti4 regulates defense-related gene expression via gcc box and non-gcc box cis elements. | the tomato transcription factor pti4, an ethylene-responsive factor (erf), interacts physically with the disease resistance protein pto and binds the gcc box cis element that is present in the promoters of many pathogenesis-related (pr) genes. we reported previously that arabidopsis plants expressing pti4 constitutively express several gcc box-containing pr genes and show reduced disease symptoms compared with wild-type plants after inoculation with pseudomonas syringae pv tomato or erysiphe oro ... | 2003 | 14630974 |
| structure and expression of phosphoenolpyruvate carboxylase kinase genes in solanaceae. a novel gene exhibits alternative splicing. | phosphorylation of phosphoenolpyruvate carboxylase (pepc; ec 4.1.1.31) plays an important role in the control of central metabolism in higher plants. two ppck (pepc kinase) genes have been identified in tomato (lycopersicon esculentum cv alicante), hereafter termed leppck1 and leppck2. the function of the gene products has been confirmed by transcription of full-length cdnas, translation, and in vitro assay of kinase activity. previously studied ppck genes contain a single intron. leppck2 also c ... | 2003 | 14630963 |
| purification and characterization of a phytase from pseudomonas syringae mok1. | a phytase (ec 3.1.3.8) from pseudomonas syringae mok1 was purified to apparent homogeneity in two steps employing cation and an anion exchange chromatography. the molecular weight of the purified enzyme was estimated to be 45 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. the optimal activity occurred at ph 5.5 and 40 degrees c. the michaelis constant (km) and maximum reaction rate (vmax) for sodium phytate were 0.38 mm and 769 u/mg of protein, respectively. the enzym ... | 2003 | 14629009 |
| translocated intimin receptor and its chaperone interact with atpase of the type iii secretion apparatus of enteropathogenic escherichia coli. | few interactions have been reported between effectors and components of the type iii secretion apparatus, although many interactions have been demonstrated between type iii effectors and their cognate chaperones. it is thought that chaperones may play a role in directing effectors to the type iii secretion apparatus. the atpase flii in the flagellar assembly apparatus plays a pivotal role in interacting with other components of the apparatus and with substrates of the flagellar system. we perfor ... | 2003 | 14617638 |
| genetic evidence that expression of nahg modifies defence pathways independent of salicylic acid biosynthesis in the arabidopsis-pseudomonas syringae pv. tomato interaction. | the salicylic acid (sa)-induction deficient (sid) mutants of arabidopsis, eds5 and sid2 accumulate normal amounts of camalexin after inoculation with pseudomonas syringae pv. tomato (pst), while transgenic nahg plants expressing an sa hydroxylase that degrades sa have reduced levels of camalexin and exhibit a higher susceptibility to different pathogens compared to the sid mutants. sid2 encodes an isochorismate synthase necessary for the synthesis of sa. nahg was shown to act epistatically to th ... | 2003 | 14617091 |
| virulence systems of pseudomonas syringae pv. tomato promote bacterial speck disease in tomato by targeting the jasmonate signaling pathway. | pseudomonas syringae pv. tomato strain dc3000 (pst dc3000) causes bacterial speck disease on tomato. the pathogenicity of pst dc3000 depends on both the type iii secretion system that delivers virulence effector proteins into host cells and the phytotoxin coronatine (cor), which is thought to mimic the action of the plant hormone jasmonic acid (ja). we found that a ja-insensitive mutant (jai1) of tomato was unresponsive to cor and highly resistant to pst dc3000, whereas host genotypes that are d ... | 2003 | 14617079 |
| pcc1: a merging point for pathogen defence and circadian signalling in arabidopsis. | using a cdna-array we identified expressed sequence tag 163b24t7 as rapidly up-regulated in arabidopsis thaliana (l.) heynh. after pathogen exposure. detailed expression analysis revealed that the corresponding gene is up-regulated not only after exposure to avirulent pseudomonas syringae pv. tomato but also to virulent strains. this up-regulation is dependent on functional salicylic acid defence-signalling pathways. moreover, we found the gene was circadian-regulated, showing peaks of expressio ... | 2004 | 14614626 |
| genome-wide characterization of the lignification toolbox in arabidopsis. | lignin, one of the most abundant terrestrial biopolymers, is indispensable for plant structure and defense. with the availability of the full genome sequence, large collections of insertion mutants, and functional genomics tools, arabidopsis constitutes an excellent model system to profoundly unravel the monolignol biosynthetic pathway. in a genome-wide bioinformatics survey of the arabidopsis genome, 34 candidate genes were annotated that encode genes homologous to the 10 presently known enzyme ... | 2003 | 14612585 |
| development and application of a dapb-based in vivo expression technology system to study colonization of rice by the endophytic nitrogen-fixing bacterium pseudomonas stutzeri a15. | pseudomonas stutzeri a15 is a nitrogen-fixing bacterium isolated from paddy rice. strain a15 is able to colonize and infect rice roots. this strain may provide rice plants with fixed nitrogen and hence promote plant growth. in this article, we describe the use of dapb-based in vivo expression technology to identify p. stutzeri a15 genes that are specifically induced during colonization and infection (cii). we focused on the identification of p. stutzeri a15 genes that are switched on during rice ... | 2003 | 14602651 |
| population structure of alexandrium (dinophyceae) cyst formation-promoting bacteria in hiroshima bay, japan. | a total of 31 bacterial isolates that have potential alexandrium cyst formation-promoting activity (alex-cfpb) were isolated from hiroshima bay (japan), which is characterized by seasonal blooms of the toxic dinoflagellate alexandrium tamarense. the population structure of alex-cfpb was analyzed by means of restriction fragment length polymorphism analysis of the 16s rrna genes (16s rdna). fourteen ribotypes, a to n, were observed among the 31 isolates of alex-cfpb by using four restriction enzy ... | 2003 | 14602614 |
| nitric oxide does not trigger early programmed cell death events but may contribute to cell-to-cell signaling governing progression of the arabidopsis hypersensitive response. | nitric oxide (no) has been suggested to play a role in the hypersensitive response (hr). single- and double-label fluorescence microscopy experiments were conducted using arabidopsis leaves infected with pseudomonas syringae pv. tomato dc3000 carrying either avrb or avrrpt2. kinetics of no production were followed by measurement of green 4-amino-5-methylamino-2',7'-difluorofluorescein (daf-fm) triazole fluorescence in leaves coinfiltrated with daf-fm diacetate. kinetics of hypersensitive cell de ... | 2003 | 14601664 |
| flagellin glycosylation island in pseudomonas syringae pv. glycinea and its role in host specificity. | the deduced amino acid sequences of the flagellins of pseudomonas syringae pv. tabaci and p. syringae pv. glycinea are identical; however, their abilities to induce a hypersensitive reaction are clearly different. the reason for the difference seems to depend on the posttranslational modification of the flagellins. to investigate the role of this posttranslational modification in the interactions between plants and bacterial pathogens, we isolated genes that are potentially involved in the postt ... | 2003 | 14594840 |
| high throughput virus-induced gene silencing implicates heat shock protein 90 in plant disease resistance. | virus-induced gene silencing was used to assess the function of random nicotiana benthamiana cdnas in disease resistance. out of 4992 cdnas tested from a normalized library, there were 79 that suppressed a hypersensitive response (hr) associated with pto-mediated resistance against pseudomonas syringae. however, only six of these clones blocked the pto-mediated suppression of p.syringae growth. the three clones giving the strongest loss of pto resistance had inserts corresponding to hsp90 and al ... | 2003 | 14592968 |
| cytosolic hsp90 associates with and modulates the arabidopsis rpm1 disease resistance protein. | the arabidopsis protein rpm1 activates disease resistance in response to pseudomonas syringae proteins targeted to the inside of the host cell via the bacterial type iii delivery system. we demonstrate that specific mutations in the atp-binding domain of a single arabidopsis cytosolic hsp90 isoform compromise rpm1 function. these mutations do not affect the function of related disease resistance proteins. rpm1 associates with hsp90 in plant cells. the arabidopsis proteins rar1 and sgt1 are requi ... | 2003 | 14592967 |
| cloning of soybean genes induced during hypersensitive cell death caused by syringolide elicitor. | syringolide elicitors produced by bacteria expressing pseudomonas syringae pv. glycinea avirulence gene d (avrd) induce hypersensitive cell death (hcd) only in soybean (glycine max [l.] merr.) plants carrying the rpg4 disease resistance gene. employing a differential display method, we isolated 13 gene fragments induced in cultured cells of a soybean cultivar harosoy (rpg4) treated with syringolides. several genes for isolated fragments were induced by syringolides in an rpg4 cultivar acme as we ... | 2004 | 14586656 |
| a gain-of-function mutation in a plant disease resistance gene leads to constitutive activation of downstream signal transduction pathways in suppressor of npr1-1, constitutive 1. | plants have evolved sophisticated defense mechanisms against pathogen infections, during which resistance (r) genes play central roles in recognizing pathogens and initiating defense cascades. most of the cloned r genes share two common domains: the central domain, which encodes a nucleotide binding adaptor shared by apaf-1, certain r proteins, and ced-4 (nb-arc), plus a c-terminal region that encodes leu-rich repeats (lrr). in arabidopsis, a dominant mutant, suppressor of npr1-1, constitutive 1 ... | 2003 | 14576290 |
| knockout analysis of arabidopsis transcription factors tga2, tga5, and tga6 reveals their redundant and essential roles in systemic acquired resistance. | arabidopsis nonexpresser of pathogenesis-related (pr) genes (npr1) is the sole positive regulator that has been shown to be essential for the induction of systemic acquired resistance. in npr1 mutant plants, salicylic acid (sa)-mediated pr gene expression and pathogen resistance are abolished completely. npr1 has been shown to interact with three closely related tga transcription factors-tga2, tga5, and tga6-in yeast two-hybrid assays. to elucidate the biological functions of these three tga tra ... | 2003 | 14576289 |
| tissue-specific and developmentally regulated expression of a cluster of tandemly arrayed cell wall-associated kinase-like kinase genes in arabidopsis. | the arabidopsis cell wall-associated kinase (wak) and wak-like kinase (wakl) family of receptor-like kinase genes encodes transmembrane proteins with a cytoplasmic serine/threonine kinase domain and an extracellular region containing epidermal growth factor-like repeats. previous studies have suggested that some wak members are involved in plant defense and heavy metal responses, whereas others are required for cell elongation and plant development. the wak/wakl gene family consists of 26 member ... | 2003 | 14576286 |
| the effect of antifreeze proteins and poly(vinyl alcohol) on the nucleation of ice: a preliminary study. | three substances have been tested for ice nucleation inhibition. these were an antifreeze protein afp iii from the fish macrozoarces americanus, an antifreeze glycoprotein afgp from the fish dissostichus mawsoni, and an 80% hydrolysed poly(vinyl alcohol) with a molecular weight of 9 to 10 kd. a nucleation spectrometer was used to test nucleation inhibition at a range of concentrations against two types of ice nuclei: those present in tap water and a bacterial nucleator from pseudomonas syringae. ... | 2003 | 14566392 |
| analysis of specific binding involved in genomic packaging of the double-stranded-rna bacteriophage phi6. | the genomes of bacteriophage phi6 and its relatives are packaged through a mechanism that involves the recognition and translocation of the three different plus-strand transcripts of the segmented double-stranded-rna genomes into preformed polyhedral structures called procapsids or inner cores. the packaging requires the hydrolysis of nucleoside triphosphates and takes place in the order segment s-segment m, segment l. packaging is dependent upon unique sequences of about 200 nucleotides near th ... | 2003 | 14563876 |
| the is1111 family members is4321 and is5075 have subterminal inverted repeats and target the terminal inverted repeats of tn21 family transposons. | is5075 and is4321 are closely related (93.1% identical) members of the is1111 family that target a specific position in the 38-bp terminal inverted repeats of tn21 family transposons and that are inserted in only one orientation. they are 1,327 bp long and have identical ends consisting of short inverted repeats of 12 bp with an additional 7 bp (taatgag) or 6 bp (aatgag) to the left of the left inverted repeats and 3 bp (aga) or 4 bp (agat) to the right of the right inverted repeat. circular for ... | 2003 | 14563872 |
| ceramides modulate programmed cell death in plants. | the balance between the bioactive sphingolipid ceramide and its phosphorylated derivative has been proposed to modulate the amount of programmed cell death (pcd) in eukaryotes. we characterized the first ceramide kinase (cerk) mutant in any organism. the arabidopsis cerk mutant, called accelerated cell death 5, accumulates cerk substrates and shows enhanced disease symptoms during pathogen attack and apoptotic-like cell death dependent on defense signaling late in development. acd5 protein shows ... | 2003 | 14563678 |
| tertiary structure of thiopurine methyltransferase from pseudomonas syringae, a bacterial orthologue of a polymorphic, drug-metabolizing enzyme. | in humans, the enzyme thiopurine methyltransferase (tpmt) metabolizes 6-thiopurine (6-tp) medications, including 6-thioguanine, 6-mercaptopurine and azathioprine, commonly used for immune suppression and for the treatment of hematopoietic malignancies. s-methylation by tpmt prevents the intracellular conversion of these drugs into active 6-thioguanine nucleotides (6-tgns). genetic polymorphisms in the tpmt protein sequence have been associated with decreased tissue enzymatic activities and an in ... | 2003 | 14556746 |
| the botrytis susceptible1 gene encodes an r2r3myb transcription factor protein that is required for biotic and abiotic stress responses in arabidopsis. | the molecular and cellular mechanisms involved in plant resistance to the necrotrophic fungal pathogen botrytis cinerea and their genetic control are poorly understood. botrytis causes severe disease in a wide range of plant species, both in the field and in postharvest situations, resulting in significant economic losses. we have isolated the bos1 (botrytis-susceptible1) gene of arabidopsis based on a t-dna insertion allele that resulted in increased susceptibility to botrytis infection. the bo ... | 2003 | 14555693 |
| bacterial cell surface display for epitope mapping of hepatitis c virus core antigen. | cell surface expression of protein has been widely used to display enzymes and antigens. here we show that pseudomonas syringae ice nucleation protein with a deletion of internal repeating domain (inc) can be used in escherichia coli to display peptide in a conformationally active form on the outside of the folded protein by fusing to the c-terminus of inc. diagnostic potential of this technology was demonstrated by effective mapping of antigenic epitopes derived from hepatitis c virus (hcv) cor ... | 2003 | 14553932 |
| multiple hormones act sequentially to mediate a susceptible tomato pathogen defense response. | phytohormones regulate plant responses to a wide range of biotic and abiotic stresses. how a limited number of hormones differentially mediate individual stress responses is not understood. we have used one such response, the compatible interaction of tomato (lycopersicon esculentum) and xanthomonas campestris pv vesicatoria (xcv), to examine the interactions of jasmonic acid (ja), ethylene, and salicylic acid (sa). the role of ja was assessed using an antisense allene oxide cyclase transgenic l ... | 2003 | 14551324 |
| characterization of a salicylic acid- and pathogen-induced lipase-like gene in chinese cabbage. | a cdna clone for a salicylic acid-induced gene in chinese cabbage (brassica rapa subsp. pekinensis) was isolated and characterized. the cabbage gene, designated br-sil1 (for brassica rapa salicylate-induced lipase-like 1 gene), encodes a putative lipase that has the family ii lipase motif gdsxxdxg around the active site serine. a database search showed that plant genomes have a large number of genes that contain the family ii lipase motif. the lipase-like proteins include a myrosinase-associated ... | 2003 | 14536025 |
| conditional survival as a selection strategy to identify plant-inducible genes of pseudomonas syringae. | a novel strategy termed habitat-inducible rescue of survival (hirs) was developed to identify genes of pseudomonas syringae that are induced during growth on bean leaves. this strategy is based on the complementation of metxw, two cotranscribed genes that are necessary for methionine biosynthesis and required for survival of p. syringae on bean leaves exposed to conditions of low humidity. we constructed a promoter trap vector, ptrap, containing a promoterless version of the wild-type p. syringa ... | 2003 | 14532027 |
| molecular basis of pto-mediated resistance to bacterial speck disease in tomato. | the pto gene in tomato confers gene-for-gene resistance to pseudomonas syringae pv. tomato, the causative agent of bacterial speck disease. pto was first introgressed from a wild species of tomato into cultivated tomato varieties over 60 years ago and is now widely used to control speck disease. cloning of the pto gene revealed that it encodes a cytoplasmically localized serine-threonine protein kinase. the molecular basis of gene-for-gene recognition in this pathosystem is the direct physical i ... | 2003 | 14527329 |
| pathogen-responsive expression of a putative atp-binding cassette transporter gene conferring resistance to the diterpenoid sclareol is regulated by multiple defense signaling pathways in arabidopsis. | the atp-binding cassette (abc) transporters are encoded by large gene families in plants. although these proteins are potentially involved in a number of diverse plant processes, currently, very little is known about their actual functions. in this paper, through a cdna microarray screening of anonymous cdna clones from a subtractive library, we identified an arabidopsis gene (atpdr12) putatively encoding a member of the pleiotropic drug resistance (pdr) subfamily of abc transporters. atpdr12 di ... | 2003 | 14526118 |
| cleavage of the pseudomonas syringae type iii effector avrrpt2 requires a host factor(s) common among eukaryotes and is important for avrrpt2 localization in the host cell. | many phytopathogenic bacteria use a type iii secretion system to deliver type iii effector proteins into the host plant cell. the pseudomonas syringae type iii effector avrrpt2 is cleaved at a specific site when translocated into the host cell. in this study, we first demonstrate that the factor(s) required for avrrpt2 cleavage is present in extracts from animal and yeast cells, as well as plant cells. the cleavage factor in animal and plant cell extracts was heat labile but relatively insensiti ... | 2003 | 14526114 |
| rps4-mediated disease resistance requires the combined presence of rps4 transcripts with full-length and truncated open reading frames. | arabidopsis rps4 belongs to the toll/interleukin-1 receptor (tir)-nucleotide binding site (nbs)-leu-rich repeat (lrr) class of disease resistance (r) genes. like other family members in different plant species, rps4 produces alternative transcripts with truncated open reading frames. the dominant alternative rps4 transcripts are generated by retention of intron 3 or introns 2 and 3, which contain in-frame stop codons and lie downstream of the nbs-encoding exon. we analyzed the biological signifi ... | 2003 | 14523247 |
| clonal population structure of pseudomonas avellanae strains of different origin based on multilocus enzyme electrophoresis. | to assess the genetic diversity and genetic relationships of pseudomonas avellanae, the causative agent of hazelnut decline, a total of 102 strains, obtained from central italy (provinces of viterbo and rome) and northern greece, were studied using multilocus enzyme electrophoresis (mlee). their allelic variation in 10 loci was determined. all loci were polymorphic and 53 electrophoretic types (ets) were identified from the total sample. the mean genetic diversity (h) was 0.65 and this value ran ... | 2003 | 14523121 |
| activation of the fatty acid alpha-dioxygenase pathway during bacterial infection of tobacco leaves. formation of oxylipins protecting against cell death. | a pathogen-induced oxygenase showing homology to prostaglandin endoperoxide synthases-1 and -2 was recently characterized by in vitro experiments as a fatty acid alpha-dioxygenase catalyzing formation of unstable 2(r)-hydroperoxy fatty acids. to study the activity of this enzyme under in vivo conditions and to elucidate the fate of enzymatically produced 2-hydroperoxides, leaves of tobacco were analyzed for the presence of alpha-dioxygenase-generated compounds as well as for lipoxygenase (lox) p ... | 2003 | 14522973 |
| properties of a novel extracellular cell-free ice nuclei from ice-nucleating pseudomonas antarctica in-74. | some ice-nucleating bacterial strains, including pantoea ananatis (erwinia uredovora), pseudomonas fluorescens, and pseudomonas syringae isolates, were examined for the ability to shed ice nuclei into the growth medium. a novel ice-nucleating bacterium, pseudomonas antarctica in-74, was isolated from ross island, antarctica. cell-free ice nuclei from p. antarctica in-74 were different from the conventional cell-free ice nuclei and showed a unique characterization. cell-free ice nuclei were purif ... | 2003 | 14519981 |
| antibacterial and proteolytic activity in venom from the endoparasitic wasp pimpla hypochondriaca (hymenoptera: ichneumonidae). | venom from the endoparasitic wasp, pimpla hypochondriaca, is composed of a mixture of high and low molecular weight proteins, possesses phenoloxidase activity, has immunosuppressive properties, and induces paralysis in several insect species. in the present study we demonstrate that p. hypochondriaca venom also contains antibacterial and proteolytic activity. antibacterial activity was detected against the gram-negative bacteria escherichia coli and xanthamonas campestris but not against pseudom ... | 2003 | 14511827 |
| acd6, a novel ankyrin protein, is a regulator and an effector of salicylic acid signaling in the arabidopsis defense response. | the previously reported arabidopsis dominant gain-of-function mutant accelerated cell death6-1 (acd6-1) shows spontaneous cell death and increased disease resistance. acd6-1 also confers increased responsiveness to the major defense signal salicylic acid (sa). to further explore the role of acd6 in the defense response, we cloned and characterized the gene. acd6 encodes a novel protein with putative ankyrin and transmembrane regions. it is a member of one of the largest uncharacterized gene fami ... | 2003 | 14507999 |
| arabidopsis sfd mutants affect plastidic lipid composition and suppress dwarfing, cell death, and the enhanced disease resistance phenotypes resulting from the deficiency of a fatty acid desaturase. | a loss-of-function mutation in the arabidopsis ssi2/fab2 gene, which encodes a plastidic stearoyl-acyl-carrier protein desaturase, has pleiotropic effects. the ssi2 mutant plant is dwarf, spontaneously develops lesions containing dead cells, accumulates increased salicylic acid (sa) levels, and constitutively expresses sa-mediated, npr1-dependent and -independent defense responses. in parallel, jasmonic acid-regulated signaling is compromised in the ssi2 mutant. in an effort to discern the invol ... | 2003 | 14507997 |
| hsp90 interacts with rar1 and sgt1 and is essential for rps2-mediated disease resistance in arabidopsis. | rar1 and its interacting partner sgt1 play a central role in plant disease resistance triggered by a number of resistance (r) proteins. we identified cytosolic heat shock protein 90 (hsp90), a molecular chaperone, as another rar1 interacting protein by yeast two-hybrid screening. rar1 interacts with the n-terminal half of hsp90 that contains the atpase domain. hsp90 also specifically interacts with sgt1 that contains a tetratricopeptide repeat motif and a domain with similarity to the cochaperon ... | 2003 | 14504384 |
| metabolism of d-galacturonic acid by pseudomonas syringae. | 1962 | 14455905 | |
| expression of a magainin-type antimicrobial peptide gene (msi-99) in tomato enhances resistance to bacterial speck disease. | msi-99 is a synthetic analog of magainin ii (mii), a small cationic peptide highly inhibitory to a wide spectrum of microbial organisms. tomato plants were transformed to express a gene encoding the msi-99 peptide and tested for possible enhancement of resistance to important pathogens of this crop. thirty-six tomato transformants carrying an msi-99 expression vector designed to target the peptide into extracellular spaces were obtained by agrobacterium tumefaciens-mediated transformation. expre ... | 2004 | 13680135 |
| complete sequence of virulence plasmid pjm1 from the marine fish pathogen vibrio anguillarum strain 775. | the virulence plasmid pjm1 enables the fish pathogen vibrio anguillarum, a gram-negative polarly flagellated comma-shaped rod bacterium, to cause a highly fatal hemorrhagic septicemic disease in salmonids and other fishes, leading to epizootics throughout the world. the pjm1 plasmid 65,009-nucleotide sequence, with an overall g+c content of 42.6%, revealed genes and open reading frames (orfs) encoding iron transporters, nonribosomal peptide enzymes, and other proteins essential for the biosynthe ... | 2003 | 13129954 |
| control of pseudomonas syringae with streptomycin. | 1953 | 13099311 | |
| from gene trees to organismal phylogeny in prokaryotes: the case of the gamma-proteobacteria. | the rapid increase in published genomic sequences for bacteria presents the first opportunity to reconstruct evolutionary events on the scale of entire genomes. however, extensive lateral gene transfer (lgt) may thwart this goal by preventing the establishment of organismal relationships based on individual gene phylogenies. the group for which cases of lgt are most frequently documented and for which the greatest density of complete genome sequences is available is the gamma-proteobacteria, an ... | 2003 | 12975657 |
| genetic and physical localization of the soybean rpg1-b disease resistance gene reveals a complex locus containing several tightly linked families of nbs-lrr genes. | alleles or tightly linked genes at the soybean (glycine max l. merr.) rpg1 locus confer resistance to strains of pseudomonas syringae pv. glycinea that express the avirulence genes avrb or avrrpm1. we have previously mapped rpg1-b (the gene specific for avrb) to a cluster of resistance genes (r genes) with diverse specificities in molecular linkage group f. here, we describe the high-resolution physical and genetic mapping of rpg1-b to a 0.16-cm interval encompassed by two overlapping bac clones ... | 2003 | 12971605 |
| a developmental response to pathogen infection in arabidopsis. | we present evidence that susceptible arabidopsis plants accelerate their reproductive development and alter their shoot architecture in response to three different pathogen species. we infected 2-week-old arabidopsis seedlings with two bacterial pathogens, pseudomonas syringae and xanthomonas campestris, and an oomycete, peronospora parasitica. infection with each of the three pathogens reduced time to flowering and the number of aerial branches on the primary inflorescence. in the absence of co ... | 2003 | 12970499 |
| does lowering glutamine synthetase activity in nodules modify nitrogen metabolism and growth of lotus japonicus? | a cdna encoding cytosolic glutamine synthetase (gs) from lotus japonicus was fused in the antisense orientation relative to the nodule-specific lbc3 promoter of soybean (glycine max) and introduced into l. japonicus via transformation with agrobacterium tumefaciens. among the 12 independent transformed lines into which the construct was introduced, some of them showed diminished levels of gs1 mrna and lower levels of gs activity. three of these lines were selected and their t(1) progeny was furt ... | 2003 | 12970491 |
| ancient origin of the tryptophan operon and the dynamics of evolutionary change. | the seven conserved enzymatic domains required for tryptophan (trp) biosynthesis are encoded in seven genetic regions that are organized differently (whole-pathway operons, multiple partial-pathway operons, and dispersed genes) in prokaryotes. a comparative bioinformatics evaluation of the conservation and organization of the genes of trp biosynthesis in prokaryotic operons should serve as an excellent model for assessing the feasibility of predicting the evolutionary histories of genes and oper ... | 2003 | 12966138 |
| local context finder (lcf) reveals multidimensional relationships among mrna expression profiles of arabidopsis responding to pathogen infection. | a major task in computational analysis of mrna expression profiles is definition of relationships among profiles on the basis of similarities among them. this is generally achieved by pattern recognition in the distribution of data points representing each profile in a high-dimensional space. some drawbacks of commonly used pattern recognition algorithms stem from their use of a globally linear space and/or limited degrees of freedom. a pattern recognition method called local context finder (lcf ... | 2003 | 12960373 |
| colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of fusarium oxysporum. | fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. the objective of this study was to compare the abilities of a pathogenic strain (foln3) and a nonpathogenic strain (fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, a ... | 2003 | 12957934 |