Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| ndr1, a locus of arabidopsis thaliana that is required for disease resistance to both a bacterial and a fungal pathogen. | we have employed arabidopsis thaliana as a model host plant to genetically dissect the molecular pathways leading to disease resistance. a. thaliana accession col-0 is susceptible to the bacterial pathogen pseudomonas syringae pv. tomato strain dc3000 but resistant in a race-specific manner to dc3000 carrying any one of the cloned avirulence genes avrb, avrrpm1, avrrpt2, and avrpph3. fast-neutron-mutagenized col-0 m2 seed was screened to identify mutants susceptible to dc3000(avrb). disease assa ... | 1995 | 11607554 |
| expression of the tomato pto gene in tobacco enhances resistance to pseudomonas syringae pv tabaci expressing avrpto. | the pto gene encodes a serine-threonine kinase that confers resistance in tomato to pseudomonas syringae pv tomato strains expressing the avirulence gene avrpto. we examined the ability of pto to function in tobacco, a species that is sexually incompatible with tomato. evidence that a heterologous pto-like signal transduction pathway is present in tobacco was suggested by the fact that tobacco line wisconsin-38 exhibits a hypersensitive response after infection with p. syringae pv tabaci express ... | 1995 | 12242354 |
| the active oxygen response of cell suspensions to incompatible bacteria is not sufficient to cause hypersensitive cell death. | the inoculation of tobacco (nicotiana tabacum l.) suspension cells with bacterial pathogens that elicit the hypersensitive response (hr) in leaves has been shown to elicit production of active oxygen. this response occurs in two phases, the second of which occurs 1 to 3 h after bacterial addition and is unique to hr-causing interactions. the relationship between the phase ii active oxygen response and the hr was characterized using pseudomonas syringae pv syringae and p. fluorescens (phir11), wh ... | 1996 | 12226215 |
| a complex array of proteins related to the multimeric leucine aminopeptidase of tomato. | leucine aminopeptidase (lap) mrnas are induced in response to mechanical wounding, pathogen infection, and insect infestation (v. pautot, f.m. holzer, b. reisch, l.l. walling [1993] proc natl acad sci usa 90: 9906-9910). polyclonal antibodies to a glutathione s-transferase-lap fusion protein and affinity-purified antibodies recognizing lap antigenic determinants detected four classes of polypeptides in tomato (lycopersicon esculentum) leaves. all four classes had multiple polypeptides in two-dim ... | 1996 | 12226257 |
| interference between two specific pathogen recognition events mediated by distinct plant disease resistance genes. | we demonstrate that the interaction of the avirulence gene avrrpt2 and the cognate resistance gene rps2 interferes with the interaction of avrrpm1-rpm1 in arabidopsis. interference is mediated outside of the bacterial pathogen pseudomonas syringae, presumably at the level of recognition of avr-dependent signals, yet does not require the wild-type rps2 product. a numerical excess of p. syringae expressing avrrpm1 can overcome this interference in mixed inoculations. the interference of avrrpt2-rp ... | 1996 | 12239384 |
| the pto kinase mediates a signaling pathway leading to the oxidative burst in tomato. | the pto gene encodes a serine/threonine kinase that confers resistance in tomato to pseudomonas syringae pv. tomato strains that express the avirulence gene avrpto. partial characterization of the pto signal transduction pathway and the availability of transgenic tomato lines (+/- pto) make this an ideal system for exploring the molecular basis of disease resistance. in this paper, we test two transgenic tomato cell suspension cultures (+/-pto) for production of h2o2 following independent challe ... | 1996 | 11038525 |
| arabidopsis thaliana defense-related protein eli3 is an aromatic alcohol:nadp+ oxidoreductase. | we expressed a cdna encoding the arabidopsis thaliana defense-related protein eli3-2 in escherichia coli to determine its biochemical function. based on a protein database search, this protein was recently predicted to be a mannitol dehydrogenase [williamson, j. d., stoop, j. m. h., massel, m. o., conkling, m. a. & pharr, d. m. (1995) proc. natl. acad. sci. usa 92, 7148-7152]. studies on the substrate specificity now revealed that eli3-2 is an aromatic alcohol: nadp+ oxidoreductase (benzyl alcoh ... | 1996 | 11038530 |
| flagellar genes from rhodobacter sphaeroides are homologous to genes of the flif operon of salmonella typhimurium and to the type-iii secretion system. | a flagellar region of the genome of rhodobacter sphaeroides was cloned and sequenced. three orfs were identified and arranged in the same order as flih, flii and flij of salmonella typhimurium (st). orf2 is highly similar to flii from st (49% similarity) showing walker's a and b motifs. similar scores were found with proteins of the type-iii secretion system of virulence factors. orf3 shows 16.4 and 11.1% similarity to flij from st and bacillus subtilis, respectively. this work also shows that o ... | 1996 | 8621091 |
| suppression of a sensor kinase-dependent phenotype in pseudomonas syringae by ribosomal proteins l35 and l20. | the lema gene of pseudomonas syringae pv. syringae encodes the sensor kinase of a bacterial two-component signal transduction system. phenotypes that are lema dependent in p. syringae include lesion formation on bean and production of extracellular protease and the antibiotic syringomycin. recently, the gaca gene has been identified as encoding the response regulator of the lema regulon. to identify additional components that interact with lema, suppressors of a lema mutation were sought. a locu ... | 1996 | 8626280 |
| gene repression by the ferric uptake regulator in pseudomonas aeruginosa: cycle selection of iron-regulated genes. | the expression of at least 24 distinct genes of pseudomonas aeruginosa pao1 is under direct control of the "ferric uptake regulator" (fur). novel targets of the fur protein were isolated in a powerful selex (systematic evolution of ligands by exponential enrichment)-like cycle selection consisting of in vitro dna-fur interaction, binding to anti-fur antibody, purification on protein g, and pcr amplification. dna fragments obtained after at least three exponential enrichment cycles were cloned an ... | 1996 | 8633080 |
| phenotypic expression of pseudomonas syringae avr genes in e. coli is linked to the activities of the hrp-encoded secretion system. | the specific recognition of elicitors produced by plant pathogenic bacteria carrying avirulence (avr) genes is postulated to initiate cellular defense responses in plants expressing corresponding resistance genes. the biochemical functions of most avr genes, however, are not known. a heterologous system was developed to phenotypically express pseudomonas syringae avr genes in escherichia coli cells that required the p. syringae hrp cluster. e. coli mc4100 transformants carrying the plasmic-borne ... | 1996 | 8634477 |
| ozone-induced responses in arabidopsis thaliana: the role of salicylic acid in the accumulation of defense-related transcripts and induced resistance. | exposure of arabidopsis thaliana to ozone results in the expression of a number of defense-related genes that are also induced during a hypersensitive response. a potential common link between the activation of defense gene expression during a hypersensitive response and by ozone treatment is the production of active oxygen species and the accumulation of hydrogen peroxide. here we report that salicylic acid accumulation, which can be induced by hydrogen peroxide and is required for the expressi ... | 1996 | 8643534 |
| molecular cloning and functional identification of a plant ornithine decarboxylase cdna. | a cdna for a plant ornithine decarboxylase (odc), a key enzyme in putrescine and polyamine biosynthesis, has been isolated from root cultures of the solanaceous plant datura stramonium. reverse transcription-pcr employing degenerate oligonucleotide primers representing conserved motifs from other eukaryotic odcs was used to isolate the cdna. the longest open reading frame potentially encodes a peptide of 431 amino acids and exhibits similarity to other eukaryotic odcs, prokaryotic and eukaryotic ... | 1996 | 8660289 |
| nucleotide sequences of four pathogen-induced alfalfa peroxidase-encoding cdnas. | we constructed an alfalfa cdna library from mrna extracted from leaves after infection with pseudomonas syringae (incompatible interaction). screening with oligodeoxyribonucleotides designed from regions conserved in all known peroxidases allowed the isolation of four cdnas (msprx1a, 1b, 1c and 2). sequence analysis revealed the presence of open reading frames of 351, 355, 358 and 323 amino acids, respectively, with the characteristic consensus sequences of plant peroxidases. sequence comparison ... | 1996 | 8666247 |
| tomato prf is a member of the leucine-rich repeat class of plant disease resistance genes and lies embedded within the pto kinase gene cluster. | in tomato, resistance to pseudomonas syringae pv. tomato (pst) strains expressing the avirulence gene avrpto requires the presence of at least two host genes, designated pto and prf. here we report that prf encodes a protein with leucine-zipper, nucleotide-binding, and leucine-rich repeat motifs, as are found in a number of resistance gene products from other plants. prf mutant alleles (4) were found to carry alterations within the prf coding sequence. a genomic fragment containing prf complemen ... | 1996 | 8689679 |
| molecular analysis of closely related copper- and streptomycin-resistance plasmids in pseudomonas syringae pv. syringae. | the genetic relationship of a group of copper (cur) and streptomycin (smr) resistance plasmids and their pseudomonas syringae pv. syringae hosts was examined. each of these plasmids contained sequences homologous to the oriv and par sequences from posu900, a cryptic p. syringae pv. syringae plasmid. analysis of restriction digest patterns of plasmid dna indicated that the plasmids could be clustered into four groups; two of the groups contained multiple members which differed by only a few fragm ... | 1996 | 8700971 |
| properties of beta-lactamase from pseudomonas syringae. | pseudomonas syringae isolate br2r produces tabtoxin, a beta-lactam-containing antibiotic, and the causative agent of wildfire disease of green bean (phaseolus vulgaris). beta-lactamase production has been suggested as the mechanism that protects p. syringae from tabtoxin. we sought to determine whether the organism produces beta-lactamase and whether the enzyme plays a role in protection from this antibiotic. p. syringae and mutants defective in tabtoxin production and resistance produce beta-la ... | 1996 | 8704658 |
| calcium-mediated apoptosis in a plant hypersensitive disease resistance response. | avirulent pathogens elicit a battery of plant defenses, often accompanied by collapse of the challenged cells. in soybean cells, sustained accumulation of h2o2 from an oxidative burst cues localized host cell death. such hypersensitive cell death appears to be an active process, but little is known about the mechanisms underlying cellular collapse. | 1996 | 8723347 |
| isolation of arabidopsis mutants with enhanced disease susceptibility by direct screening. | to discover which components of plant defense responses make significant contributions to limiting pathogen attack, we screened a mutagenized population of arabidopsis thaliana for individuals that exhibit increased susceptibility to the moderately virulent bacterial pathogen pseudomonas syringae pv. maculicola es4326 (psm es4326). the 12 enhanced disease susceptibility (eds) mutants isolated included alleles of two genes involved in phytoalexin biosynthesis (pad2, which had been identified prev ... | 1996 | 8725243 |
| the repb gene required for production of extracellular enzymes and fluorescent siderophores in pseudomonas viridiflava is an analog of the gaca gene of pseudomonas syringae. | two genes, designated repa and repb, are involved in the regulation of the synthesis of extracellular pectate lyase, protease, and alginate in pseudomonas viridiflava. the repa gene has been shown to encode a protein highly homologous to several bacterial sensors in the two-component regulator family including the lema of pseudomonas syringae. in this study, the repb locus, initially identified in a 6.3-kb ecori genomic fragment of p. viridiflava, was further characterized. results obtained from ... | 1996 | 8742358 |
| isolation of arabidopsis genes that differentiate between resistance responses mediated by the rps2 and rpm1 disease resistance genes. | the arabidopsis disease resistance gene rps2 is involved in recognition of bacterial pathogens carrying the avirulence gene avrrpt2, and the rpm1 resistance gene is involved in recognition of pathogens carrying avrrpm1 or avrb. we identified and cloned two arabidopsis genes, aig1 and aig2 (for avrrpt2-induced gene), that exhibit rps2- and avrrpt2-dependent induction early after infection with pseudomonas syringae pv maculicola strain es4326 carrying avrrpt2. however, es4326 carrying avrrpm1 or a ... | 1996 | 8742710 |
| benzothiadiazole induces disease resistance in arabidopsis by activation of the systemic acquired resistance signal transduction pathway. | benzothiadiazole (bth) is a novel chemical activator of disease resistance in tobacco, wheat and other important agricultural plants. in this report, it is shown that bth works by activating sar in arabidopsis thaliana. bth-treated plants were resistant to infection by turnip crinkle virus, pseudomonas syringae pv 'tomato' dc3000 and peronospora parasitica. chemical treatment induced accumulation of mrnas from the sar-associated genes, pr-1, pr-2 and pr-5. bth treatment induced both pr-1 mrna ac ... | 1996 | 8758979 |
| structural and mechanistic similarities of 6-phosphogluconate and 3-hydroxyisobutyrate dehydrogenases reveal a new enzyme family, the 3-hydroxyacid dehydrogenases. | rat 3-hydroxyisobutyrate dehydrogenase exhibits significant amino acid sequence homology with 6-phosphogluconate dehydrogenase, d-phenylserine dehydrogenase from pseudomonas syringae, and a number of hypothetical proteins encoded by genes of microbial origin. key residues previously proposed to have roles in substrate binding and catalysis in sheep 6-phosphogluconate dehydrogenase are highly conserved in this entire family of enzymes. site-directed mutagenesis, chemical modification, and substra ... | 1996 | 8766712 |
| expression of the pseudomonas syringae avirulence protein avrb in plant cells alleviates its dependence on the hypersensitive response and pathogenicity (hrp) secretion system in eliciting genotype-specific hypersensitive cell death. | the nonpathogenic bacteria pseudomonas fluorescens and escherichia coli can elicit a genotype-specific hypersensitive response (hr) in plants if they express both the hr and pathogenesis (hrp) protein secretion system and the hrpz harpin from p. syringae pv syringae 61 and a p. syringae avirulence (avr) gene whose presence is recognized by a corresponding disease resistance gene in the plant. we have found that the recognition event appears to require transfer of the avr protein into the plant c ... | 1996 | 8768370 |
| structure and activity of persicomycins, toxins produced by a pseudomonas syringae pv. persicae/prunus persica isolate. | a toxigenic property has been demonstrated in a pseudomonas syringae pv. persicae/prunus persica isolate. several substances, which are named persicomycins, have been purified in variable quantities from cultures. the structures of four of them were established by nmr and chemical ionization mass spectrometry. these compounds are 3-(3'-hydroxy)hydroxy fatty acids and thus represent a new family among the phytobacterial toxins. other minor substances have also been isolated and have been shown to ... | 1996 | 8774716 |
| systemic resistance in arabidopsis induced by biocontrol bacteria is independent of salicylic acid accumulation and pathogenesis-related gene expression. | systemic acquired resistance is a pathogen-inducible defense mechanism in plants. the resistant state is dependent on endogenous accumulation of salicylic acid (sa) and is characterized by the activation of genes encoding pathogenesis-related (pr) proteins. recently, selected nonpathogenic, root-colonizing biocontrol bacteria have been shown to trigger a systemic resistance response as well. to study the molecular basis underlying this type of systemic resistance, we developed an arabidopsis-bas ... | 1996 | 8776893 |
| distribution of pseudomonas syringae pathovars into twenty-three o serogroups. | serological reactions of pseudomonas syringae and pseudomonas viridiflava were studied by ouchterlony double diffusion. a total of 55 polyclonal antisera, containing anti-lipopolysaccharide (anti-lps) precipitating antibodies, were cross-tested against antigenic suspensions of 51 strains. twenty-three o serogroups were defined, primarily on the reaction of the type strains. two families of o serogroups showed antigenic crossreactivities (pha, mop1, mop2, mop3, hel1, hel2, and syr1; persavtom1, p ... | 1996 | 8779574 |
| two cold-inducible genes encoding lipid transfer protein ltp4 from barley show differential responses to bacterial pathogens. | the barley genes hvltp4.2 and hvltp4.3 both encode the lipid transfer protein ltp4 and are less than 1 kb apart in tail-to-tail orientation. they differ in their non-coding regions from each other and from the gene corresponding to a previously reported ltp4 cdna (now ltp4.1). southern blot analysis indicated the existence of three or more ltp4 genes per haploid genome and showed considerable polymorphism among barley cultivars. we have investigated the transient expression of genes hvltp4.2 and ... | 1996 | 8804389 |
| the rsma- mutants of erwinia carotovora subsp. carotovora strain ecc71 overexpress hrpnecc and elicit a hypersensitive reaction-like response in tobacco leaves. | erwinia carotovora subsp. carotovora wild-type strain ecc71 does not elicit the hypersensitive reaction (hr) in tobacco leaves. by mini-tn5-km and chemical mutagenesis we have isolated rsma- mutants of ecc71 that produce high basal levels of pectate lyases, polygalacturonase, cellulase, and protease; they also are hypervirulent. the rsma- mutants, but not their parent strains, elicit an hr-like response in tobacco leaves. this reaction is characterized by the rapid appearance of water soaking fo ... | 1996 | 8810071 |
| use of translational fusions to the maltose-binding protein to produce and purify proteins in pseudomonas syringae and assess their activity in vivo. | a simple approach is described for the production and purification of proteins in pseudomonas syringae. the strategy involves the use of the tac promoter, the maltose-binding protein, and the broad-host-range vector, prk415. this approach was used to partially purify two proteins involved in coronatine biosynthesis from p. syringae. the activity of the fusions was demonstrated in vivo in complementation experiments using the appropriate mutants. | 1996 | 8810079 |
| analysis of the role of the pseudomonas syringae pv. syringae hrpz harpin in elicitation of the hypersensitive response in tobacco using functionally non-polar hrpz deletion mutations, truncated hrpz fragments, and hrma mutations. | pseudomonas syringae pv. syringae, like many plant pathogenic bacteria, secretes a 'harpin' protein that can elicit the hypersensitive response (hr), a defensive cellular suicide, in non-host plants. the harpin-encoding hrpz gene is located in an operon that also encodes hrp secretion pathway components and is part of the functional cluster of hrp genes carried on cosmid phir11 that enables saprophytic bacteria like escherichia coli and pseudomonas fluorescens to elicit the hr in tobacco leaves. ... | 1996 | 8820642 |
| syr2, a gene necessary for syringomycin growth inhibition of saccharomyces cerevisiae. | the pseudomonas syringae cyclic lipodepsipeptide syringomycin inhibits the growth of saccharomyces cerevisiae. a novel yeast gene, syr2, was found to complement two syringomycin-resistant s. cerevisiae mutants. syr2 was cloned, sequenced, and shown to encode a 349 amino acid protein located in the endoplasmic reticulum. syr2 was identical to sur2, which is involved in survival during nutritional starvation. gene disruption or overexpression of syr2 did not affect cell viability or ergosterol lev ... | 1996 | 8868422 |
| defense reaction in medicago sativa: a gene encoding a class 10 pr protein is expressed in vascular bundles. | infiltration of medicago sativa leaves with a suspension of pseudomonas syringae pv. pisi elicits the accumulation of several mrna classes. a clone, designated as mspr10-1, encoding a polypeptide exhibiting strong similarity to the class 10 pr protein was isolated and characterized from a cdna library prepared from leaf mrna. the corresponding gene was shown to be developmentally regulated: except in roots, its expression was not detectable in other analyzed organs of healthy plants (hypocotyls, ... | 1996 | 8870270 |
| mode of action of the arabidopsis thaliana phytoalexin camalexin and its role in arabidopsis-pathogen interactions. | the virulent arabidopsis thaliana pathogen pseudomonas syringae pv. maculicola strain es4326 (psm es4326) and other gram-negative bacteria are sensitive to camalexin (3-thiazol-2'-yl-indole), the arabidopsis phytoalexin. furthermore, psm es4326 is unable to degrade camalexin or to become tolerant to it. apparently, psm es4326 is a successful pathogen even though it elicits synthesis of a host phytoalexin to which it is sensitive. assays of membrane integrity revealed that, like other phytoalexin ... | 1996 | 8870273 |
| the pseudomonas syringae hrp regulation and secretion system controls the production and secretion of multiple extracellular proteins. | pseudomonas syringae pv. tomato dc3000 produces seven to eight major extracellular proteins (exps) in a minimal medium inducing hrp genes. using a polyclonal antibody against dc3000 exps, we have determined that the production and secretion of five exps (exp-60, exp-45, exp-43, exp-22, and exp-10) are under the control of the hrp regulation and secretion system. | 1996 | 8892851 |
| hrp gene-dependent induction of hin1: a plant gene activated rapidly by both harpins and the avrpto gene-mediated signal. | two classes of bacterial genes are involved in the elicitation of the plant hypersensitive response (hr) in resistant plants: hrp genes and avr genes. hrp genes have been shown to be involved in the production and secretion of a new class of bacterial virulence/avirulence proteins, including harpin of erwinia amylovora and harpinpss of pseudomonas syringae. the ability of avr genes in the elicitation of the hr/resistance is dependent on functional hrp genes. the relationships between harpins and ... | 1996 | 8893538 |
| resistance to ultraviolet light in pseudomonas syringae: sequence and functional analysis of the plasmid-encoded rulab genes. | the indigenous plasmids, ppsr1 and ppsr5, were each shown to confer resistance to ultraviolet light (uv) in pseudomonas syringae (ps) pv. syringae ff5. the uv-resistance (uvr) determinant was subcloned from a cosmid library of ppsr1, and sequence analysis revealed the presence of two orfs, designated rulab which are homologous to the escherichia coli umudc mutagenic dna repair systems and other plasmid-encoded uvr operons. amino acid (aa) alignments indicated that rulab are most closely related ... | 1996 | 8921848 |
| immunochemical characterization of o polysaccharides composing the alpha-d-rhamnose backbone of lipopolysaccharide of pseudomonas syringae and classification of bacteria into serogroups o1 and o2 with monoclonal antibodies. | murine monoclonal antibodies (mabs) reacting with pseudomonas syringae lipopolysaccharide (lps) o polysaccharides (ops) composed of tetra- and tri-alpha-d-rhamnose repeats in the backbone [3)d-rha(alpha1-3)d-rha(alpha1-2)d-rha(alpha1-2)d-rha(alpha1] and [3)d-rha(alpha1-3)d-rha(alpha1-2)d-rha(alpha1] were generated and used for immunochemical analysis and for serological classification of the bacteria. a total of 195 of 358 p. syringae strains tested representing 21 pathovars were shown to share ... | 1996 | 8932301 |
| the azotobacter vinelandii gene algj encodes an outer-membrane protein presumably involved in export of alginate. | the algj gene from azotobacter vinelandii was cloned using a labelled rna probe representing the coding region of the alge gene from pseudomonas aeruginosa. dna sequencing revealed an orf of 1452 bp encoding a protein of 484 amino acid residues with a calculated molecular mass of 54611 da. an rna probe corresponding to alge was also used for southern hybridization of chromosomal dna, which showed that alge-related dna sequences are also present in the alginate-producing phytopathogen species pse ... | 1996 | 8936313 |
| molecular basis of gene-for-gene specificity in bacterial speck disease of tomato | transient expression of the pseudomonas syringae avirulence gene avrpto in plant cells resulted in a pto-dependent necrosis. the avrpto avirulence protein was observed to interact directly with the pto resistance protein in the yeast two-hybrid system. mutations in the pto and avrpto genes which reduce in vivo activity had parallel effects on association in the two-hybrid assay. these data suggest that during infection the pathogen delivers avrpto into the plant host cell and that resistance is ... | 1996 | 8953034 |
| characterization of eds1, a mutation in arabidopsis suppressing resistance to peronospora parasitica specified by several different rpp genes. | the interaction between arabidopsis and the biotrophic oomycete peronospora parasitica (downy mildew) provides an attractive model pathosystem to identify molecular components of the host that are required for genotype-specific recognition of the parasite. these components are the so-called rpp genes (for resistance to p. parasitica). mutational analysis of the ecotype wassilewskija (ws-0) revealed an rpp-nonspecific locus called eds1 (for enhanced disease susceptibility) that is required for th ... | 1996 | 8953768 |
| characterization of two epiphytic bacteria from soybean leaves with antagonistic activities against pseudomonas syringae pv. glycinea. | the strains 48b/90 and 22d/93 are naturally occurring ephiphytes which were isolated from soybean leaves. on the basis of pheno- and genotypic characteristics 48b/90 was identified as erwinia herbicola and 22d/93 as pseudomonas syringae. these two isolates produced biological active substances against different indicator organisms. the e. herbicola strain showed clear antagonistic properties against escherichia coli and pseudomonas syringae pv. glycinea, but not against geotrichum candidum. 22d/ ... | 1996 | 8956493 |
| isolation and characterization of a tobacco mosaic virus-inducible myb oncogene homolog from tobacco. | salicylic acid (sa) plays an important role in signaling the activation of plant defense responses against pathogen attack including induction of pathogenesis-related (pr) proteins. to gain further insight into the sa-mediated signal transduction pathway, we have isolated and characterized a tobacco mosaic virus (tmv)-inducible myb oncogene homolog (myb1) from tobacco. the myb1 gene was induced upon tmv infection during both the hypersensitive response and development of systemic acquired resist ... | 1996 | 8962166 |
| in vitro antifungal and fungicidal activities and erythrocyte toxicities of cyclic lipodepsinonapeptides produced by pseudomonas syringae pv. syringae. | recent increases in fungal infections, the few available antifungal drugs, and increasing fungal resistance to the available antifungal drugs have resulted in a broadening of the search for new antifungal agents. strains of pseudomonas syringae pv. syringae produce cyclic lipodepsinonapeptides with antifungal activity. the in vitro antifungal and fungicidal activities of three cyclic lipodepsinonapeptides (syringomycin e, syringotoxin b, and syringostatin a) against medically important isolates ... | 1996 | 9124827 |
| identification of a new arabidopsis disease resistance locus, rps4, and cloning of the corresponding avirulence gene, avrrps4, from pseudomonas syringae pv. pisi. | a molecular genetic approach was used to study the interaction between arabidopsis and an avirulence gene from pseudomonas syringae pv. pisi. p. syringae pv. pisi strain 151 induces a hypersensitive response (hr) when inoculated on the arabidopsis accession po-1. a genomic cosmid library was constructed from dna from p. syringae pv. pisi strain 151 and a cosmid was identified that causes the normally virulent p. syringae pv. tomato strain dc3000 to induce an hr on po-1. the cosmid was subcloned ... | 1996 | 8589423 |
| molecular recognition of pathogen attack occurs inside of plant cells in plant disease resistance specified by the arabidopsis genes rps2 and rpm1. | the arabidopsis thaliana disease resistance genes rps2 and rpm1 belong to a class of plant disease resistance genes that encode proteins that contain an n-terminal tripartite nucleotide binding site (nbs) and a c-terminal tandem array of leucine-rich repeats. rps2 and rpm1 confer resistance to strains of the bacterial phytopathogen pseudomonas syringae carrying the avirulence genes avrrpt2 and avrb, respectively. in these gene-for-gene relationships, it has been proposed that pathogen avirulence ... | 1996 | 8986840 |
| the sink-specific and stress-regulated arabidopsis stp4 gene: enhanced expression of a gene encoding a monosaccharide transporter by wounding, elicitors, and pathogen challenge. | a cdna for the arabidopsis stp4 gene (for sugar transport protein 4) was isolated, and the properties of the encoded protein were studied in schizosaccharomyces pombe. the stp4 monosaccharide h+ symporter is composed of 514 amino acids and has a calculated molecular mass of 57.1 kd. rna gel blot analyses revealed that stp4 is expressed primarily in roots and flowers of arabidopsis. this was shown in more detail with stp4 promoter-beta-glucuronidase (gus) plants yielding strong stp4-driven gus ac ... | 1996 | 8989877 |
| characterisation of genes involved in biosynthesis of coronafacic acid, the polyketide component of the phytotoxin coronatine. | coronafacic acid (cfa) is the polyketide component of coronatine (cor), a phytotoxin produced by the plant pathogen, pseudomonas syringae. in the present study we have determined the nucleotide sequence of a 3.92-kb dna fragment involved in cfa biosynthesis. analysis of the sequence revealed four complete open reading frames (orfs) designated cfa1 to cfa4 and one incomplete orf (cfa5), all transcribed in the same direction. the predicted translation products of cfa1, cfa2 and cfa3 showed related ... | 1996 | 8996103 |
| characterization of genes required for pilus expression in pseudomonas syringae pathovar phaseolicola. | nonpiliated, phage phi 6-resistant mutants of pseudomonas syringae pv. phaseolicola were generated by tn5 transposon mutagenesis. a p. syringae pv. phaseolicola lr700 cosmid library was screened with tn5-containing ecori fragments cloned from nonpiliated mutants. the cosmid clone pvk253 complemented the nonpiliated mutant strain hb2.5. a 3.8-kb sequenced region spanning the tn5 insertion site contained four open reading frames. the transposon-inactivated gene, designated pilp, is 525 bp long, po ... | 1996 | 8550460 |
| raindrop momentum triggers growth of leaf-associated populations of pseudomonas syringae on field-grown snap bean plants. | observational and microclimate modification experiments were conducted under field conditions to determine the role of the physical environment in effecting large increases in phyllosphere population sizes of pseudomonas syringae pv. syringae, the causal agent of bacterial brown spot disease of snap bean (phaseolus vulgaris l.). comparisons of daily changes in population sizes of p. syringae on three plantings of snap bean cultivar cascade and one of cultivar eagle with weather conditions indica ... | 1996 | 16535362 |
| utility of microcosm studies for predicting phylloplane bacterium population sizes in the field. | population sizes of two ice nucleation-active strains of pseudomonas syringae were compared on leaves in controlled environments and in the field to determine the ability of microcosm studies to predict plant habitat preferences in the field. the p. syringae strains investigated were the parental strains of recombinant deletion mutant strains deficient in ice nucleation activity that had been field tested for their ability to control plant frost injury. the population size of the p. syringae str ... | 1996 | 16535405 |
| bacterial avirulence genes. | although more than 30 bacterial avirulence genes have been cloned and characterized, the function of the gene products in the elictitation of resistance is unknown in all cases but one. the product of avrd from pseudomonas syringae pv. glycinea likely functions indirectly to elicit resistance in soybean, that is, evidence suggests the gene product is an enzyme involved in elicitor production. in most if not all cases, bacterial avirulence gene function is dependent on interactions with the hyper ... | 1996 | 15012539 |
| specificity of induced resistance in the tomato, lycopersicon esculentum. | specificity in the induced responses of tomato foliage to arthropod herbivores was investigated. we distinguished between two aspects of specificity: specificity of effect (the range of organisms affected by a given induced response), and specificity of elicitation (ability of the plant to generate distinct chemical responses to different damage types). specificity of effect was investigated by examining the effect of restricted feeding by helicoverpa zea on the resistance of tomato plants to an ... | 1997 | 28307296 |
| ethylene production by pseudomonas syringae pathovars in vitro and in planta. | significant amounts of ethylene were produced by pseudomonas syringae pv. glycinea, pv. phaseolicola (which had been isolated from viny weed pueraria lobata [willd.] ohwi [common name, kudzu]), and pv. pisi in synthetic medium. on the other hand, the bean strains of p. syringae pv. phaseolicola and strains of 17 other pathovars did not produce ethylene. p. syringae pv. glycinea and p. syringae pv. phaseolicola produced nearly identical levels of ethylene (about 5 x 10(sup-7) nl h(sup-1) cell(sup ... | 1997 | 16535480 |
| contribution of the regulatory gene lema to field fitness of pseudomonas syringae pv. syringae. | in pseudomonas syringae pv. syringae, lema is required for brown spot lesion formation on snap bean and for production of syringomycin and extracellular proteases (e. m. hrabak and d. k. willis, j. bacteriol. 174: 3011-3022, 1992; e. m. hrabak and d. k. willis, mol. plant-microbe interact. 6:368-375, 1993; d. k. willis, e. m. hrabak, j. j. rich, t. m. barta, s. e. lindow, and n. j. panopoulos, mol. plant-microbe interact. 3:149-156, 1990). the lema mutant nps3136 (lema1::tn5) was previously foun ... | 1997 | 16535727 |
| relative expression and stability of a chromosomally integrated and plasmid-borne marker gene fusion in environmentally competent bacteria. | a xyle-icec transcriptional fusion was created by ligatinga dna fragment harboring the cloned xyle structural gene from the tol plasmid of pseudomonas putida mt-2 into the cloned icec gene of pseudomonas syringae cit7. this fusion construct was integrated into the chromosome of pseudomonas syringae cit7 by homologous recombination. both cis-merodiploid strain cit7m17 and marker exchange strain cit7h69 produced the xyle gene product, catechol2,3-dioxygenase. strain cit7m17, in which xyle was infl ... | 1997 | 9003582 |
| transformation of pbr322-derived plasmids in phytopathogenicpseudomonas avenae and enhanced transformation in itsproline-auxotrophic mutant | efficient transformation of pbr322 and its derivedplasmids, which have been widely used as cloning vectors in escherichiacoli, was observed in pseudomonas avenae (k1), the pathogen ofleaf blight disease in cereals. moreover, there was a 10- to 50-foldtransformation efficiency (1.3-3.0 x 10(6)/&mgr;g dna) in theproline-auxotrophic mutant (pr47), whose virulence to rice seedlingsdecreased. similar enhancement of the frequency of transfer by mobilizationof rsf1010, a broad host range plasmid, was o ... | 1997 | 9009065 |
| alleles of pto and fen occur in bacterial speck-susceptible and fenthion-insensitive tomato cultivars and encode active protein kinases. | the pto gene was derived originally from the wild tomato species lycopersicon pimpinellifolium and confers resistance to pseudomonas syringae pv tomato strains expressing the avirulence gene avrpto. the fen gene is also derived from l. pimpinellifolium and confers sensitivity to the insecticide fenthion. we have now isolated and characterized the alleles of pto and fen from cultivated tomato, l. esculentum, and designated them pto and fen. high conservation of genome organization between the two ... | 1997 | 9014365 |
| assessment of genetic diversity among strains of pseudomonas syringae by pcr-restriction fragment length polymorphism analysis of rrna operons with special emphasis on p. syringae pv. tomato. | phylogenetic relationships among 77 bacterial strains belonging to pseudomonas syringae and pseudomonas viridiflava species were assessed by analysis of the pcr-restriction fragment length polymorphism (rflp) patterns of three dna fragments corresponding to rrs and rrl genes and the internal transcribed spacer, its1. no difference among all strains in rrs and rrl genes was observed with 14 restriction enzymes, which confirms the close relationships existing between these two species. the nucleot ... | 1997 | 9023928 |
| the hrpa and hrpc operons of erwinia amylovora encode components of a type iii pathway that secretes harpin. | a 6.2-kb region of dna corresponding to complementation groups ii and iii of the erwinia amylovora hrp gene cluster was analyzed. transposon mutagenesis indicated that the two complementation groups are required for secretion of harpin, an elicitor of the hypersensitive reaction. the sequence of the region revealed 10 open reading frames in two putative transcription units: hrpa, hrpb, hrcj, hrpd, and hrpe in the hrpa operon (group iii) and hrpf, hrpg, hrcc, hrpt, and hrpv in the hrpc operon (gr ... | 1997 | 9045830 |
| rapid stimulation of a soybean protein-serine kinase that phosphorylates a novel bzip dna-binding protein, g/hbf-1, during the induction of early transcription-dependent defenses. | the g-box (cacgtg) and h-box (cctacc) cis elements function in the activation of phenylpropanoid biosynthetic genes involved in the elaboration of lignin precursors, phytoalexins and the secondary signal salicylic acid as early responses to pathogen attack. we have isolated a soybean cdna encoding a novel bzip protein, g/hbf-1, which binds to both the g-box and adjacent h-box in the proximal region of the chalcone synthase chs15 promoter. while g/hbf-1 transcript and protein levels do not increa ... | 1997 | 9049302 |
| expression of avrpphb, an avirulence gene from pseudomonas syringae pv. phaseolicola, and the delivery of signals causing the hypersensitive reaction in bean. | protein production encoded by the avirulence gene avrpphb from pseudomonas syringae pv. phaseolicola was examined. incorporation of [35s]-labeled methionine into the avrpphb protein indicated processing of the full-length peptide in escherichia coli to give a major 28-kda product. the 28-kda native peptide was isolated from e. coli following over-expression of avrpphb and found not to elicit the hypersensitive response (hr) after infiltration into bean leaves. antiserum raised to the 28-kda pept ... | 1997 | 9057331 |
| localization of hydrogen peroxide accumulation during the hypersensitive reaction of lettuce cells to pseudomonas syringae pv phaseolicola. | the active oxygen species hydrogen peroxide (h2o2) was detected cytochemically by its reaction with cerium chloride to produce electron-dense deposits of cerium perhydroxides. in uninoculated lettuce leaves, h2o2 was typically present within the secondary thickened walls of xylem vessels. inoculation with wild-type cells of pseudomonas syringae pv phaseolicola caused a rapid hypersensitive reaction (hr) during which highly localized accumulation of h2o2 was found in plant cell walls adjacent to ... | 1997 | 9061952 |
| salicylic acid potentiates an agonist-dependent gain control that amplifies pathogen signals in the activation of defense mechanisms. | the phenylpropanoid-derived natural product salicylic acid (sa) plays a key role in disease resistance. however, sa administered in the absence of a pathogen is a paradoxically weak inductive signal, often requiring concentrations of 0.5 to 5 mm to induce acquired resistance or related defense mechanisms or to precondition signal systems. in contrast, endogenous sa accumulates to concentrations of < 70 microm at the site of attempted infection. here, we show that although 10 to 100 microm sa had ... | 1997 | 9061956 |
| multiple loci of pseudomonas syringae pv. syringae are involved in pathogenicity on bean: restoration of one lesion-deficient mutant requires two trna genes. | a mutational analysis of lesion-forming ability was undertaken in pseudomonas syringae pv. syringae b728a, causal agent of bacterial brown spot disease of bean. following a screen of 6,401 tn5-containing derivatives of b728a on bean pods, 26 strains that did not form disease lesions were identified. nine of the mutant strains were defective in the ability to elicit the hypersensitive reaction (hr) and were shown to contain tn5 insertions within the p. syringae pv. syringae hrp region. ten hr+ mu ... | 1997 | 9079910 |
| conservation of the multidrug resistance efflux gene oprm in pseudomonas aeruginosa. | an intragenic probe derived from the multidrug resistance gene oprm hybridized with genomic dna from all 20 serotypes of pseudomonas aeruginosa and from all 34 environmental and clinical isolates tested, indicating that the mexa-mexb-oprm multidrug efflux system is highly conserved in this organism. the oprm probe also hybridized with genomic dna from pseudomonas aureofaciens, pseudomonas chlororaphis, pseudomonas syringae, burkholderia pseudomallei, and pseudomonas putida, suggesting that efflu ... | 1997 | 9087505 |
| arabidopsis enhanced disease susceptibility mutants exhibit enhanced susceptibility to several bacterial pathogens and alterations in pr-1 gene expression. | to identify plant defense responses that limit pathogen attack, arabidopsis eds mutants that exhibit enhanced disease susceptibility to the virulent bacterial pathogen pseudomonas syringae pv maculicola es4326 were previously identified. in this study, we show that each of four eds mutants (eds5-1, eds6-1, eds7-1, and eds9-1) has a distinguishable phenotype with respect to the degree of susceptibility to a panel of bacterial phytopathogens and the ability to activate pathogenesis-related pr-1 ge ... | 1997 | 9090877 |
| hrp pilus: an hrp-dependent bacterial surface appendage produced by pseudomonas syringae pv. tomato dc3000. | hypersensitive response and pathogenicity (hrp) genes control the ability of major groups of plant pathogenic bacteria to elicit the hypersensitive response (hr) in resistant plants and to cause disease in susceptible plants. a number of hrp proteins share significant similarities with components of the type iii secretion apparatus and flagellar assembly apparatus in animal pathogenic bacteria. here we report that pseudomonas syringae pv. tomato strain dc3000 (race 0) produces a filamentous surf ... | 1997 | 9096416 |
| lipopeptide phytotoxins produced by pseudomonas syringae pv. syringae: comparison of the biosurfactant and ion channel-forming activities of syringopeptin and syringomycin. | the phytopathogenic bacterium pseudomonas syringae pv. syringae produces two classes of necrosis-inducing lipodepsipeptide toxins commonly referred to as the syringomycins and syringopeptins. members of the syringomycins class are pore-forming cytotoxins that act by promoting passive transmembrane ion flux. in this study, we test the hypothesis that syringopeptin forms sp22a and sp22b likewise function as pore-forming cytotoxins and are similar in activity to syringomycin in artificial and plant ... | 1997 | 9100379 |
| molecular cloning, characterization, and mutagenesis of a pel gene from pseudomonas syringae pv. lachyrmans encoding a member of the erwinia chrysanthemi pelade family of pectate lyases. | the pels gene from pseudomonas syringae pv. lachrymans 859 was cloned by heterologous expression in nonpectolytic p. syringae pv. syringae buvs1, using genomic dna libraries constructed with two novel broad-host-range cosmid vectors, pcpp34 and pcpp47. screening of p. syringae pv. syringae transconjugants for the ability to pit pectate media at ph 6.0 and 8.5 yielded several overlapping clones of the same dna region. ultrathin-layer isoelectric focusing gels, activity-stained with diagnostically ... | 1997 | 9100381 |
| comparison of avrd alleles from pseudomonas syringae pv. glycinea. | avirulence gene d alleles resided on indigenous plasmids in races 0, 2, 3, 4, 5, and 6 of pseudomonas syringae pv. glycinea (psg), but the allele in race 1 appeared to be chromosomal. these were all nonfunctional avirulence genes because they neither induced the avirulence phenotype on rpg4 soybean cultivars nor directed the production of syringolide elicitors when expressed in escherichia coli cells. the predicted proteins encoded by the seven psg avrd genes were very similar to that of a funct ... | 1997 | 9100386 |
| characterization of o-antigens from different strains of pseudomonas syringae pv. tabaci. | o-antigens (lipopolysaccharides, lps) were isolated by nacl extraction from microbial biomass of pseudomonas syringae pv. tabaci and purified by ultracentrifugation. individual structural components of the lps macromolecule (o-specific polysaccharide (o-ps), core oligosaccharide, and lipid a) were obtained and characterized. fatty acids 3-oh-c10:0, c12:0, 2-oh-c12:0, 3-oh-c12:0, c16:1, c16:0, c18:1, and c18:0 were identified in the lipid a composition. glucosamine, ethanolamine, and phosphoethan ... | 1997 | 9113726 |
| [the properties of the proteins and nucleic acids of 3 pseudomonas syringae phages]. | the 9b, 123, 788/8 pseudomonas syringae phages were investigated. paag electrophoretic profiles of phage proteins were identical for all three phages except the minor polypeptide having molecular weight 35,000 da. the band corresponding to this protein was present only in 9b and 788/8 phage protein profiles. amino acid composition of phage proteins varied insignificantly showing prevalence of asp, glu, ala, leu. phage dna fragments electrophoresis, carried out after processing with specific endo ... | 1997 | 9480014 |
| characterization of dapb, a gene required by pseudomonas syringae pv. tabaci br2.024 for lysine and tabtoxinine-beta-lactam biosynthesis. | the dapb gene, which encodes l-2,3-dihydrodipicolinate reductase, the second enzyme of the lysine branch of the aspartic amino acid family, was cloned and sequenced from a tabtoxin-producing bacterium, pseudomonas syringae pv. tabaci br2.024. the deduced amino acid sequence shared 60 to 90% identity to known dapb gene products from gram-negative bacteria and 19 to 21% identity to the dapb products from gram-positive bacteria. the consensus sequence for the nad(p)h binding site [(v/i)(a/g)(v/i)xg ... | 1997 | 8990304 |
| phytoalexin-deficient mutants of arabidopsis reveal that pad4 encodes a regulatory factor and that four pad genes contribute to downy mildew resistance. | we are working to determine the role of the arabidopsis phytoalexin, camalexin, in protecting the plant from pathogen attack by isolating phytoalexin-deficient (pad) mutants in the accession columbia (col-0) and examining their response to pathogens. mutations in pad1, pad2, and pad4 caused enhanced susceptibility to the bacterial pathogen pseudomonas syringae pv. maculicola strain es4326 (psmes4326), while mutations in pad3 or pad5 did not. camalexin was not detected in any of the double mutant ... | 1997 | 9136026 |
| characterization of is1474, an insertion sequence of the is21 family isolated from pseudomonas alcaligenes ncib 9867. | a new insertion sequence (is) designated is1474 was isolated from pseudomonas alcaligenes ncib 9867 (p25x). is1474 is a 2632 bp element which showed a characteristic is structure with 12 bp inverted repeats (irs) flanking a 2608 bp central region. is1474 contained four open reading frames (orf1-orf4), two in each orientation. similarities were detected between orf1 and orf2 and the putative transposases of the is21 family. sequences upstream from is1474 were found to display up to 89% homology w ... | 1997 | 9141667 |
| pilp, a pilus biogenesis lipoprotein in neisseria gonorrhoeae, affects expression of pilq as a high-molecular-mass multimer. | studies of gonococcal pilus biogenesis are fundamental to understanding organelle structure/function relationships and identifying new approaches to controlling disease. this area of research is also relevant to elucidating the basic mechanisms of outer membrane translocation of macromolecules, which requires components highly related to those involved in type iv pilus expression. previous studies have shown that products of several ancillary pil genes are required for organelle biogenesis but o ... | 1997 | 9157238 |
| detecting and characterizing n-acyl-homoserine lactone signal molecules by thin-layer chromatography. | many gram-negative bacteria regulate gene expression in response to their population size by sensing the level of acyl-homoserine lactone signal molecules which they produce and liberate to the environment. we have developed an assay for these signals that couples separation by thin-layer chromatography with detection using agrobacterium tumefaciens harboring lacz fused to a gene that is regulated by autoinduction. with the exception of n-butanoyl-l-homoserine lactone, the reporter detected acyl ... | 1997 | 9177164 |
| altered localization of hrpz in pseudomonas syringae pv. syringae hrp mutants suggests that different components of the type iii secretion pathway control protein translocation across the inner and outer membranes of gram-negative bacteria. | pseudomonas syringae pv. syringae 61 (pss61) secretes the hrpz harpin by a type iii protein secretion pathway encoded by a cluster of hrp (hypersensitive response and pathogenicity) and hrc genes. the nine hrc genes represent a subset of hrp genes that are also conserved in the type iii virulence protein secretion systems of animal pathogenic yersinia, shigella, and salmonella spp. the hrpj and hrpu operons contain seven hrc genes (counting hrcq(a) and hrcq(b) as one gene), all with additional h ... | 1997 | 9190801 |
| characterization of the cryptic plasmids of the pseudomonas alcaligenes type strain. | the species type strain of pseudomonas alcaligenes contains three small cryptic plasmids (designated pecb1, 2, and 3) of 7740, 4480, and 2700 bp, respectively. partial restriction enzyme maps have been constructed for pecb1 and 2 which on this basis do not appear to be related. pecb3 proved refractile to cutting with commonly used restriction enzymes, though it was completely rendered by those enzymes which recognize 4-bp sequences containing only g + c. this suggested that pecb3 is especially r ... | 1997 | 9200222 |
| a hairpin-loop conformation in tandem repeat sequence of the ice nucleation protein revealed by nmr spectroscopy. | the 1h-nmr spectrum of a synthetic 24-residue peptide (a1-g-v-d-s-s-l-i-a-g-y-g-s-t-q-t-s-g-s-d-s-a-l-t24; inp24), comprising three repeats of the 8-residue consensus sequence of pseudomonas syringae ice nucleation protein, was fully assigned using 2-dimensional (2d) nmr spectroscopy at 4 degrees c and 30 degrees c. close proximity of the aliphatic protons between leu7, ile8, ala9, and the ring-protons of tyr11 was indicated from the observation of the inter-molecular nuclear overhauser enhancem ... | 1997 | 9202151 |
| evidence that the pseudomonas syringae pv. syringae hrp-linked hrma gene encodes an avr-like protein that acts in an hrp-dependent manner within tobacco cells. | a 25-kb dna region, previously cloned from pseudomonas syringae pv. syringae 61 in cosmid phir11, enables nonpathogenic bacteria such as pseudomonas fluorescens and escherichia coli to elicit the hypersensitive response (hr) in tobacco (nicotiana tabacum). hrma is located within this region, adjacent to a conserved cluster of hrp genes, and is essential for nonpathogens to elicit the hr. dna sequence analysis suggested that hrma was the second of two genes in an operon and was preceded by an ope ... | 1997 | 9204563 |
| the presence of hrp genes on the pathogenicity-associated plasmid of the tumorigenic bacterium erwinia herbicola pv. gypsophilae. | the pathogenicity-associated plasmid (ppath) of erwinia herbicola pv. gypsophilae (ehg), which is present only in pathogenic strains, contains a gene cluster encoding indole-3-acetic acid and cytokinin biosynthesis. the transposon-reporter tn3-spice was used to generate nonpathogenic mutants on two overlapping cosmids, pla150 and pla352, of the ppath. a cluster of such mutations, which spanned 16 kb, mapped approximately 15 kb from the gene cluster involved in phytohormone biosynthesis. non-path ... | 1997 | 9204571 |
| hctr1: a human gene for copper uptake identified by complementation in yeast. | the molecular mechanisms responsible for the cellular uptake of copper in mammalian cells are unknown. we describe isolation of a human gene involved in this process by complementation of the yeast high-affinity copper uptake mutant, ctr1. besides complementing ctr1 growth defect on nonfermentable media, the human gene also rescues iron transport and sod1 defects in ctr1 yeast. overexpression of the gene in yeast leads to vulnerability to the toxicity of copper overload. in addition, its express ... | 1997 | 9207117 |
| analysis of the syrp gene, which regulates syringomycin synthesis by pseudomonas syringae pv. syringae. | syringomycin is a lipodepsinonapeptide phytotoxin synthesized by pseudomonas syringae pv. syringae on multienzymatic peptide synthetases. sequence analysis of the interval between the syrb and syrd genes of p. syringae pv. syringae strain b301d revealed a 1,059-bp open reading frame (orf), designated syrp. the predicted product of this orf was a 39.6-kda protein consisting of 353 amino acid residues. searches of protein sequence databases demonstrated that syrp was most similar to histidine kina ... | 1997 | 9212424 |
| the pto kinase conferring resistance to tomato bacterial speck disease interacts with proteins that bind a cis-element of pathogenesis-related genes. | in tomato, the pto kinase confers resistance to bacterial speck disease by recognizing the expression of a corresponding avirulence gene, avrpto, in the pathogen pseudomonas syringae pv. tomato. using the yeast two-hybrid system, we have identified three genes, pti4, pti5 and pti6, that encode proteins that physically interact with the pto kinase. pti4/5/6 each encode a protein with characteristics that are typical of transcription factors and are similar to the tobacco ethylene-responsive eleme ... | 1997 | 9214637 |
| characterization of the alginate biosynthetic gene cluster in pseudomonas syringae pv. syringae. | alginate, a copolymer of d-mannuronic acid and l-guluronic acid, is produced by a variety of pseudomonads, including pseudomonas syringae. alginate biosynthesis has been most extensively studied in p. aeruginosa, and a number of structural and regulatory genes from this species have been cloned and characterized. in the present study, an alginate-defective (alg-) mutant of p. syringae pv. syringae ff5 was shown to contain a tn5 insertion in algl, a gene encoding alginate lyase. a cosmid clone de ... | 1997 | 9226254 |
| use of tn5-gusa5 to investigate environmental and nutritional effects on gene expression in the coronatine biosynthetic gene cluster of pseudomonas syringae pv. glycinea. | pseudomonas syringae pv. glycinea pg4180 produces coronatine (cor), a chlorosis-inducing phytotoxin that consists of the polyketide coronafacic acid (cfa) coupled via an amide bond to the ethylcyclopropyl amino acid coronamic acid (cma). both cfa and cma function as intermediates in the pathway to coronatine, and genes encoding their synthesis have been localized: however, the precise factors that regulate the production of cor and its precursors remain unclear. in the present study, a lambda de ... | 1997 | 9226871 |
| antagonistic activities of epiphytic bacteria from soybean leaves against pseudomonas syringae pv. glycinea in vitro and in planta | 1997 | 9230099 | |
| biological activities of pseudomycin a, a lipodepsinonapeptide from pseudomonas syringae msu 16h. | similarly to other pseudomonas lipodepsinonapeptides, pseudomycin a inhibits proton extrusion from maize roots, promotes closure of stomata in vicia faba, necrosis of tobacco leaves, haemolysis of human erythrocytes, affects h(+)-atpase activity and proton translocation in plasma membrane vesicles, and stimulates succinate respiration in pea mitochondria. in general, the biological activities of pseudomycin a are lower than those of syringomycin-e, the prototype member of this family of bacteria ... | 1997 | 9237401 |
| differential induction of systemic resistance in arabidopsis by biocontrol bacteria. | selected nonpathogenic, root-colonizing bacteria are able to elicit induced systemic resistance (isr) in plants. to elucidate the molecular mechanisms underlying this type of systemic resistance, an arabidopsis-based model system was developed in which pseudomonas syringae pv. tomato and fusarium oxysporum f. sp. raphani were used as challenging pathogens. in arabidopsis thaliana ecotypes columbia and landsberg erecta, colonization of the rhizosphere by p. fluorescens strain wcs417r induced syst ... | 1997 | 9245833 |
| structure of l-a virus: a specialized compartment for the transcription and replication of double-stranded rna. | the genomes of double-stranded (ds)rna viruses are never exposed to the cytoplasm but are confined to and replicated from a specialized protein-bound compartment-the viral capsid. we have used cryoelectron microscopy and three-dimensional image reconstruction to study this compartment in the case of l-a, a yeast virus whose capsid consists of 60 asymmetric dimers of gag protein (76 kd). at 16-a resolution, we distinguish multiple domains in the elongated gag subunits, whose nonequivalent packing ... | 1997 | 9281577 |
| a possible role for acetylated intermediates in diaminopimelate and tabtoxinine-beta-lactam biosynthesis in pseudomonas syringae pv. tabaci br2.024. | the deduced product of an open reading frame (orf3) located in the tabtoxinine-beta-lactam (t beta l) biosynthetic region of pseudomonas syringae pv. tabaci br2.024 (br2.024) has significant sequence homology to the dapd products of other bacteria. dapd encodes l-2,3,4,5-tetrahydrodipicolinate succinyl coenzyme a succinyltransferase (thdpa-st), an enzyme in the diaminopimelate (dap) and lysine biosynthetic pathway. complementation studies, in vitro transcription-translation experiments, and enzy ... | 1997 | 9294453 |
| identification of a promoter region on the halomonas elongata cryptic plasmid phe1 employing the inaz reporter gene of pseudomonas syringae. | a native promoter located on the cryptic plasmid phe1 from the moderate halophile halomonas elongata was identified employing a promoterless ice nucleation gene inaz of pseudomonas syringae by direct subcloning and assaying for ice nucleation activity. the presence of the promoter was verified by inserting the corresponding intact or deleted phe1 fragment in the promoter analysis vector pkk232-8 upstream of the promoterless cat or inaz gene. only constructs carrying the intact phe1 fragment gave ... | 1997 | 9297819 |
| expression and analysis of coronafacate ligase, a thermoregulated gene required for production of the phytotoxin coronatine in pseudomonas syringae. | coronafacic acid, the polyketide component of the phytotoxin coronatine, is activated and coupled to coronamic acid via amide bond formation, a biosynthetic step presumably catalyzed by the coronafacate ligase (cfl) gene product. in the present study, cfl was fused to the carboxy terminus of male, which encodes the maltose-binding protein (mbp), and overexpressed in escherichia coli. immunoblot analysis indicated that cfl contained an atp-binding region, a motif conserved in enzymes which activa ... | 1997 | 9297822 |
| molecular organisation of the ice nucleation protein inav from pseudomonas syringae. | a new ice nucleation gene from pseudomonas syringae was isolated and overexpressed as a fully active protein in escherichia coli in order to gain experimental data about the structure of ice nucleation proteins. no evidence of a signal sequence or secondary glycosylation was found. differences in the extent of aggregation were shown to modulate the ice nucleation activity. the circular dichroism spectrum of the purified protein indicated the presence of beta-sheet structure. this finding support ... | 1997 | 9323042 |
| avirulence gene d of pseudomonas syringae pv. tomato may have undergone horizontal gene transfer. | avirulence gene d (avrd) is carried on the b-plasmid of the plant pathogen pseudomonas syringae pv. tomato with plasmid-borne avrd homologs widely distributed among the pseudomonads. we now report sequences in the soft rot pathogen erwinia carotovora that cross-hybridize to avrd suggesting a conserved function beyond avirulence. alternatively, avrd may have been transferred horizontally among species: (i) dna linked to avrd shows evidence of class ii transpositions and contains a novel is3-relat ... | 1997 | 9326365 |
| the cpr5 mutant of arabidopsis expresses both npr1-dependent and npr1-independent resistance. | the cpr5 mutant was identified from a screen for constitutive expression of systemic acquired resistance (sar). this single recessive mutation also leads to spontaneous expression of chlorotic lesions and reduced trichome development. the cpr5 plants were found to be constitutively resistant to two virulent pathogens, pseudomonas syringae pv maculicola es4326 and peronospora parasitica noco2; to have endogenous expression of the pathogenesis-related gene 1 (pr-1); and to have an elevated level o ... | 1997 | 9338960 |
| enhanced tolerance to bacterial pathogens caused by the transgenic expression of barley lipid transfer protein ltp2. | purified lipid transfer protein ltp2 from barley applied on tobacco leaves eliminated symptoms caused by infiltration of pseudomonas syringae pv. tabaci 153. growth of the pathogen in leaves of transgenic tobacco plants was retarded when compared with non-transformed controls. the percentage of inoculation points that showed necrotic lesions was greatly reduced in transgenic tobacco (17-38% versus 78%) and the average size of these lesions was 61-81% that of control. the average total lesion are ... | 1997 | 9351251 |
| sequencing of regions downstream of adda (98 degrees) and citg (289 degrees) in bacillus subtilis. | the nucleotide sequence of 17.3 kbp downstream of adda (98 degrees) on the bacillus subtilis chromosome was determined. twenty putative orfs were identified. three of them coincided with known b. subtilis genes, adda, sbcd and wpra. the product of four other orfs showed similarity to sbcc of clostridium perfringens, coth of b. subtilis, 2-hydroxyhepta-2,4-diene-1,7-diodate isomerase of methanococcus jannaschi and a putative orf of pseudomonas syringae. in addition, a sequence of 7.6 kbp downstre ... | 1997 | 9353931 |