| the cloned avirulence gene avrpto induces disease resistance in tomato cultivars containing the pto resistance gene. | resistance of tomato plants to the bacterial pathogen pseudomonas syringae pv. tomato race 0 is controlled by the locus pto. a bacterial avirulence gene was cloned by constructing a cosmid library from an avirulent p. syringae pv. tomato race, conjugating the recombinants into a strain of p. syringae pv. maculicola virulent on a tomato cultivar containing pto, and screening for those clones that converted the normally virulent phenotype to avirulence. the cloned gene, designated avrpto, reduced ... | 1992 | 1537802 |
| identification of pseudomonas syringae pathogens of arabidopsis and a bacterial locus determining avirulence on both arabidopsis and soybean. | to develop a model system for molecular genetic analysis of plant-pathogen interactions, we studied the interaction between arabidopsis thaliana and the bacterial pathogen pseudomonas syringae pv tomato (pst). pst strains were found to be virulent or avirulent on specific arabidopsis ecotypes, and single ecotypes were resistant to some pst strains and susceptible to others. in many plant-pathogen interactions, disease resistance is controlled by the simultaneous presence of single plant resistan ... | 1991 | 1824334 |
| rapid identification of markers linked to a pseudomonas resistance gene in tomato by using random primers and near-isogenic lines. | an approach to isolating dna sequences that are linked to important plant genes is described. the strategy is based upon a recent modification of the polymerase chain reaction in which synthetic primers are used to amplify random sequences from genomic dna. this technique, used in conjunction with near-isogenic lines (which differ only by the presence or absence of the target gene and a small region of surrounding dna), leads to the rapid identification of sequences linked to the gene of interes ... | 1991 | 2006172 |
| induction of the copper resistance operon from pseudomonas syringae. | cupric sulfate induced mrna specific to the copper resistance gene cluster previously cloned from pseudomonas syringae pv. tomato pt23. mrna from each of the four genes of this cluster responded in a similar manner to induction over time and with different concentrations of cupric sulfate. promoter fusion constructs indicated the presence of a single copper-inducible promoter upstream from the first open reading frame. | 1988 | 2457580 |
| plasmid-mediated production of the phytotoxin coronatine in pseudomonas syringae pv. tomato. | pseudomonas syringae pv. tomato pt23.2 produces the chlorosis-inducing phytotoxin coronatine. thirty-eight chlorosis-defective mutants of pt23.2 were previously generated by using the transposon tn5. five mutants contained tn5 insertions in the indigenous plasmid ppt23a; the remaining 33 mutants either were missing ppt23a (29 mutants) or contained deletions in this plasmid (4 mutants). these results suggested that ppt23a was involved in coronatine production in strain pt23.2. this plasmid was in ... | 1989 | 2536682 |
| indigenous plasmids in pseudomonas syringae pv. tomato: conjugative transfer and role in copper resistance. | twenty strains of pseudomonas syringae pv. tomato were examined for the presence of plasmid dna. p. syringae pv. tomato plasmids were grouped into five size classes: class a ranged from 95 to 103 kilobases (kb); class b ranged from 71 to 83 kb; class c ranged from 59 to 67 kb; class d ranged from 37 to 39 kb; and class e was 29 kb. all strains contained at least two plasmids in classes a and b. the conjugative ability of p. syringae pv. tomato plasmids in three strains was demonstrated by mobili ... | 1986 | 3003029 |
| molecular cloning of copper resistance genes from pseudomonas syringae pv. tomato. | a cosmid library of copper-resistant (cur) pseudomonas syringae pv. tomato pt23 plasmid dna was constructed and mobilized into the copper-sensitive recipient p. syringae pv. syringae ps61. one resultant cosmid clone, pcop1 (46 kilobases), conferred copper resistance. the pt23 cur gene(s) was located on pcop1 by subcloning psti restriction endonuclease fragments of pcop1 in the broad-host-range vector prk404. a subclone containing a 4.4-kilobase psti fragment conferred cur on ps61. the cur gene(s ... | 1987 | 3027030 |
| use of a gene expression system based on potato virus x to rapidly identify and characterize a tomato pto homolog that controls fenthion sensitivity. | a novel transient gene expression system was used to study both the tomato disease resistance gene pto and a pto homolog designated fen. the gene expression system was based on potato virus x (pvx). tomato plants that were both susceptible to strains of pseudomonas syringae pv tomato carrying the corresponding avirulence gene avrpto and insensitive to the insecticide fenthion were infected with in vitro-generated transcripts of pvx derivatives containing either pto or fen. expression of the pto ... | 1995 | 7734960 |
| a member of the tomato pto gene family confers sensitivity to fenthion resulting in rapid cell death. | leaves of tomato cultivars that contain the pto bacterial resistance locus develop small necrotic lesions within 24 hr after exposure to fenthion, an organophosphorous insecticide. recently, the pto gene was isolated and shown to be a putative serine/threonine protein kinase. pto is one member of a multigene family that is clustered within a 400-kb region on chromosome 5. here, we report that another member of this gene family, termed fen, is responsible for the sensitivity to fenthion. fen was ... | 1994 | 7827490 |
| isolation and sequence analysis of the pseudomonas syringae pv. tomato gene encoding a 2,3-diphosphoglycerate-independent phosphoglyceromutase. | pseudomonas syringae pv. tomato dc3481, a tn5-induced mutant of the tomato pathogen dc3000, cannot grow and elicit disease symptoms on tomato seedlings. it also cannot grow on minimal medium containing malate, citrate, or succinate, three of the major organic acids found in tomatoes. we report here that this mutant also cannot use, as a sole carbon and/or energy source, a wide variety of hexoses and intermediates of hexose catabolism. uptake studies have shown that dc3481 is not deficient in tra ... | 1995 | 7896694 |
| molecular cloning, chromosomal mapping, and sequence analysis of copper resistance genes from xanthomonas campestris pv. juglandis: homology with small blue copper proteins and multicopper oxidase. | copper-resistant strains of xanthomonas campestris pv. juglandis occur in walnut orchards throughout northern california. the copper resistance genes from a copper-resistant strain c5 of x. campestris pv. juglandis were cloned and located on a 4.9-kb clai fragment, which hybridized only to dna of copper-resistant strains of x. campestris pv. juglandis, and was part of an approximately 20-kb region which was conserved among such strains of x. campestris pv. juglandis. hybridization analysis indic ... | 1994 | 8282694 |
| characterization of the promoter of avirulence gene d from pseudomonas syringae pv. tomato. | the avirulence gene d (avrd) from pseudomonas syringae pv. tomato comprises the first open reading frame (orf) of a putative operon consisting of at least five tandem orfs. the promoter of the avrd operon was localized to a 150-bp dna fragment occurring 5' to the avrd gene by using the tn7-lux and gus reporter systems. the avrd promoter in p. syringae pv. tomato and p. syringae pv. glycinea was poorly expressed when bacteria were grown in complex culture media but was activated during bacterial ... | 1993 | 8376338 |
| 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 |
| 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 |
| 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 |
| 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 |
| erwinia amylovora secretes dspe, a pathogenicity factor and functional avre homolog, through the hrp (type iii secretion) pathway. | erwinia amylovora was shown to secrete dspe, a pathogenicity factor of 198 kda and a functional homolog of avre of pseudomonas syringae pv. tomato. dspe was identified among the supernatant proteins isolated from cultures grown in an hrp gene-inducing minimal medium by immunodetection with a dspe-specific antiserum. secretion required an intact hrp pathway. | 1998 | 9555912 |
| the pseudomonas syringae pv. tomato hrpw protein has domains similar to harpins and pectate lyases and can elicit the plant hypersensitive response and bind to pectate. | the host-specific plant pathogen pseudomonas syringae elicits the hypersensitive response (hr) in nonhost plants and secretes the hrpz harpin in culture via the hrp (type iii) secretion system. previous genetic evidence suggested the existence of another harpin gene in the p. syringae genome. hrpw was found in a region adjacent to the hrp cluster in p. syringae pv. tomato dc3000. hrpw encodes a 42. 9-kda protein with domains resembling harpins and pectate lyases (pels), respectively. hrpw has ke ... | 1998 | 9748456 |
| suppressors of the arabidopsis lsd5 cell death mutation identify genes involved in regulating disease resistance responses. | cell death is associated with the development of the plant disease resistance hypersensitive reaction (hr). arabidopsis lsd mutants that spontaneously exhibit cell death reminiscent of the hr were identified previously. to study further the regulatory context in which cell death acts during disease resistance, one of these mutants, lsd5, was used to isolate new mutations that suppress its cell death phenotype. using a simple lethal screen, nine lsd5 cell death suppressors, designated phx (for th ... | 1999 | 9872969 |
| the gene coding for the hrp pilus structural protein is required for type iii secretion of hrp and avr proteins in pseudomonas syringae pv. tomato. | bacterial surface appendages called pili often are associated with dna and/or protein transfer between cells. the exact function of pili in the transfer process is not understood and is a matter of considerable debate. the hrp pilus is assembled by the hrp type iii protein secretion system of pseudomonas syringae pv. tomato (pst) strain dc3000. in this study, we show that the hrpa gene, which encodes the major subunit of the hrp pilus, is required for secretion of putative virulence proteins, su ... | 2000 | 10681465 |
| expression of 35s::pto globally activates defense-related genes in tomato plants. | the tomato (lycopersicon esculentum) resistance gene pto confers resistance to the bacterial pathogen pseudomonas syringae pv tomato carrying the avirulent gene avrpto. overexpressing pto under the control of the cauliflower mosaic virus 35s promoter constitutively activates defense responses in the absence of pathogen infection and nonspecifically enhances disease resistance. to elucidate the mechanisms underlying this resistance, we isolated cdnas corresponding to transcripts that accumulated ... | 2001 | 11500562 |
| ethylene regulates the susceptible response to pathogen infection in tomato. | ethylene evolution occurs concomitantly with the progression of disease symptoms in response to many virulent pathogen infections in plants. a tomato mutant impaired in ethylene perception-never ripe-exhibited a significant reduction in disease symptoms in comparison to the wild type after inoculations of both genotypes with virulent bacterial (xanthomonas campestris pv vesicatoria and pseudomonas syringae pv tomato) and fungal (fusarium oxysporum f sp lycopersici) pathogens. bacterial spot dise ... | 1998 | 9501111 |
| 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 |
| identification of arabidopsis ethylene-responsive element binding factors with distinct induction kinetics after pathogen infection. | ethylene-responsive element binding factors (erf) proteins are plant-specific transcription factors, many of which have been linked to stress responses. we have identified four arabidopsis erf genes whose expression was specifically induced by avirulent and virulent strains of the bacterial pathogen pseudomonas syringae pv tomato, with overlapping but distinct induction kinetics. however, a delay in erf mrna accumulation after infection with the virulent strain was observed when compared with th ... | 2002 | 11950980 |
| rps2, an arabidopsis disease resistance locus specifying recognition of pseudomonas syringae strains expressing the avirulence gene avrrpt2. | a molecular genetic approach was used to identify and characterize plant genes that control bacterial disease resistance in arabidopsis. a screen for mutants with altered resistance to the bacterial pathogen pseudomonas syringae pv. tomato (pst) expressing the avirulence gene avrrpt2 resulted in the isolation of four susceptible rps (resistance to p. syringae) mutants. the rps mutants lost resistance specifically to bacterial strains expressing avrrpt2 as they retained resistance to pst strains ... | 1993 | 8400869 |
| tomato transcription factors pti4, pti5, and pti6 activate defense responses when expressed in arabidopsis. | the pti4, pti5, and pti6 proteins from tomato were identified based on their interaction with the product of the pto disease resistance gene, a ser-thr protein kinase. they belong to the ethylene-response factor (erf) family of plant-unique transcription factors and bind specifically to the gcc-box cis element present in the promoters of many pathogenesis-related (pr) genes. here, we show that these tomato erfs are localized to the nucleus and function in vivo as transcription activators that re ... | 2002 | 11971137 |
| leucine aminopeptidase: an inducible component of the defense response in lycopersicon esculentum (tomato). | a leucine aminopeptidase (ec 3.4.11.1) cdna clone (dr57) that was induced in response to pseudomonas syringae pv. tomato (p.s. tomato) infection was isolated using a subtractive hybridization-enriched cdna probe. genomic dna blot analysis showed that the tomato genome had two leucine aminopeptidase genes. the levels of dr57 mrnas after p.s. tomato infection and mechanical wounding were determined in two inbred tomato lines that exhibit susceptibility and resistance to p.s. tomato. dr57 mrnas wer ... | 1993 | 8234334 |
| tomato mutants altered in bacterial disease resistance provide evidence for a new locus controlling pathogen recognition. | we have employed a genetic approach to study the resistance of tomato to the phytopathogenic bacterium pseudomonas syringae pv tomato. resistance to p. s. tomato depends upon expression of the pto locus in tomato, which encodes a protein with similarity to serine/threonine protein kinases and recognizes pathogen strains expressing the avirulence gene avrpto. eleven tomato mutants were isolated with altered resistance to p. s. tomato strains expressing avrpto. we identified mutations both in the ... | 1994 | 7911348 |
| intergeneric transfer and functional expression of the tomato disease resistance gene pto. | plant disease resistance loci have been used successfully in breeding programs to transfer traits from resistant germplasm to susceptible plant cultivars. the molecular cloning of plant disease resistance genes now permits the transfer of such traits across species boundaries by genetic transformation of recipient hosts. the tomato disease resistance gene pto confers resistance to strains of the bacterial pathogen pseudomonas syringae pv tomato expressing the avirulence gene avrpto. transformati ... | 1995 | 7580250 |
| nucleotide sequence and organization of copper resistance genes from pseudomonas syringae pv. tomato. | the nucleotide sequence of a 4.5-kilobase copper resistance determinant from pseudomonas syringae pv. tomato revealed four open reading frames (orfs) in the same orientation. deletion and site-specific mutational analyses indicated that the first two orfs were essential for copper resistance; the last two orfs were required for full resistance, but low-level resistance could be conferred in their absence. five highly conserved, direct 24-base repeats were found near the beginning of the second o ... | 1988 | 3372485 |
| assessment of the importance of similarity in carbon source utilization profiles between the biological control agent and the pathogen in biological control of bacterial speck of tomato. | bacterial speck of tomato, caused by pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by ... | 2002 | 12200291 |
| arabidopsis gp91phox homologues atrbohd and atrbohf are required for accumulation of reactive oxygen intermediates in the plant defense response. | reactive oxygen intermediates (roi) are strongly associated with plant defense responses. the origin of these roi has been controversial. arabidopsis respiratory burst oxidase homologues (rboh genes) have been proposed to play a role in roi generation. we analyzed lines carrying dspm insertions in the highly expressed atrbohd and atrbohf genes. both are required for full roi production observed during incompatible interactions with the bacterial pathogen pseudomonas syringae pv. tomato dc3000(av ... | 2002 | 11756663 |
| 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 |
| ancient origin of pathogen recognition specificity conferred by the tomato disease resistance gene pto. | we have investigated the origin of the pto disease resistance (r) gene that was previously identified in the wild tomato species lycopersicon pimpinellifolium and isolated by map-based cloning. pto encodes a serine-threonine protein kinase that specifically recognizes strains of pseudomonas syringae pv. tomato (pst) that express the avirulence gene avrpto. we examined an accession of the distantly related wild species lycopersicon hirsutum var. glabratum that exhibits avrpto-specific resistance ... | 2001 | 11172075 |
| 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 |
| enhancement of induced disease resistance by simultaneous activation of salicylate- and jasmonate-dependent defense pathways in arabidopsis thaliana. | the plant-signaling molecules salicylic acid (sa) and jasmonic acid (ja) play an important role in induced disease resistance pathways. cross-talk between sa- and ja-dependent pathways can result in inhibition of ja-mediated defense responses. we investigated possible antagonistic interactions between the sa-dependent systemic acquired resistance (sar) pathway, which is induced upon pathogen infection, and the ja-dependent induced systemic resistance (isr) pathway, which is triggered by nonpatho ... | 2000 | 10890883 |
| thr38 and ser198 are pto autophosphorylation sites required for the avrpto-pto-mediated hypersensitive response. | the tomato pto kinase confers resistance to pseudomonas syringae pv. tomato expressing the avrpto protein. to elucidate the role of pto autophosphorylation in disease resistance, eight sites autophosphorylated by pto in vitro were identified by a combination of hplc purification of tryptic phosphopeptides, maldi-tof/ms analysis and edman degradation. mutational analysis of the autophosphorylation sites revealed that pto residues thr38 and ser198 are required for avrpto-pto- mediated elicitation ... | 2000 | 10811617 |
| pti4 is induced by ethylene and salicylic acid, and its product is phosphorylated by the pto kinase. | the tomato pti4 gene encodes a transcription factor that was identified on the basis of its specific interaction with the product of the pto disease resistance gene in a yeast two-hybrid system. we show here that the pti4 protein specifically binds the gcc-box cis element, which is present in the promoter region of many pathogenesis-related (pr) genes. expression of the pti4 gene in tomato leaves was rapidly induced by ethylene and by infection with pseudomonas syringae pv tomato, and this induc ... | 2000 | 10810149 |
| leucine aminopeptidase rnas, proteins, and activities increase in response to water deficit, salinity, and the wound signals systemin, methyl jasmonate, and abscisic acid | lapa rnas, proteins, and activities increased in response to systemin, methyl jasmonate, abscisic acid (aba), ethylene, water deficit, and salinity in tomato (lycopersicon esculentum). salicylic acid inhibited wound-induced increases of lapa rnas. experiments using the aba-deficient flacca mutant indicated that aba was essential for wound and systemin induction of lapa, and aba and systemin acted synergistically to induce lapa gene expression. in contrast, pin2 (proteinase inhibitor 2) was not d ... | 1999 | 10444081 |
| constitutively active pto induces a prf-dependent hypersensitive response in the absence of avrpto. | resistance in tomato to pseudomonas syringae pv tomato (avrpto) is conferred by the gene pto in a gene-for-gene relationship. a hypersensitive disease resistance response (hr) is elicited when pto and avrpto are expressed experimentally within the same plant cell. the kinase capability of pto was required for avrpto-dependent hr induction. systematic mutagenesis of the activation segment of pto kinase confirmed the homologous p+1 loop as an avrpto-binding determinant. specific amino acid substit ... | 1999 | 10369664 |
| enhanced expression and activation of the alternative oxidase during infection of arabidopsis with pseudomonas syringae pv tomato. | cyanide-resistant ("alternative") respiration was studied in arabidopsis during incompatible and compatible infection with pseudomonas syringae pv tomato dc3000. total leaf respiration increased as the leaves became necrotic, as did the cyanide-resistant component that was sensitive to salicylhydroxamic acid. infiltration of leaves with an avirulent strain rapidly induced alternative oxidase (aox) mrna, whereas the increase was delayed in the compatible combination. the increase in mrna correlat ... | 1999 | 10364404 |
| the arabidopsis ssi1 mutation restores pathogenesis-related gene expression in npr1 plants and renders defensin gene expression salicylic acid dependent. | the arabidopsis npr1 gene was previously shown to be required for the salicylic acid (sa)- and benzothiadiazole (bth)-induced expression of pathogenesis-related (pr) genes and systemic acquired resistance. the dominant ssi1 (for suppressor of sa insensitivity) mutation characterized in this study defines a new component of the sa signal transduction pathway that bypasses the requirement of npr1 for expression of the pr genes and disease resistance. the ssi1 mutation caused pr (pr-1, bgl2 [pr-2], ... | 1999 | 9927638 |
| overexpression of pto activates defense responses and confers broad resistance. | the tomato disease resistance (r) gene pto specifies race-specific resistance to the bacterial pathogen pseudomonas syringae pv tomato carrying the avrpto gene. pto encodes a serine/threonine protein kinase that is postulated to be activated by a physical interaction with the avrpto protein. here, we report that overexpression of pto in tomato activates defense responses in the absence of the pto-avrpto interaction. leaves of three transgenic tomato lines carrying the cauliflower mosaic virus 35 ... | 1999 | 9878629 |
| molecular analysis of avirulence gene avrrpt2 and identification of a putative regulatory sequence common to all known pseudomonas syringae avirulence genes. | the avrrpt2 locus from pseudomonas syringae pv. tomato causes virulent strains of p. syringae to be avirulent on some, but not all, lines of arabidopsis thaliana and glycine max (soybean). we determined the dna sequence of the avrrpt2 locus and identified the avrrpt2 gene as a 768-bp open reading frame encoding a putative 28.2-kda protein. deletion analysis and transcription studies provided further evidence that this open reading frame encodes avrrpt2. we found that the avrrpt2 gene also has av ... | 1993 | 8335641 |
| the complete genome sequence of the arabidopsis and tomato pathogen pseudomonas syringae pv. tomato dc3000. | we report the complete genome sequence of the model bacterial pathogen pseudomonas syringae pathovar tomato dc3000 (dc3000), which is pathogenic on tomato and arabidopsis thaliana. the dc3000 genome (6.5 megabases) contains a circular chromosome and two plasmids, which collectively encode 5,763 orfs. we identified 298 established and putative virulence genes, including several clusters of genes encoding 31 confirmed and 19 predicted type iii secretion system effector proteins. many of the virule ... | 2003 | 12928499 |
| genomewide identification of pseudomonas syringae pv. tomato dc3000 promoters controlled by the hrpl alternative sigma factor. | the ability of pseudomonas syringae pv. tomato dc3000 to parasitize tomato and arabidopsis thaliana depends on genes activated by the hrpl alternative sigma factor. to support various functional genomic analyses of dc3000, and specifically, to identify genes involved in pathogenesis, we developed a draft sequence of dc3000 and used an iterative process involving computational and gene expression techniques to identify virulence-implicated genes downstream of hrpl-responsive promoters. hypersensi ... | 2002 | 11854524 |
| functional analysis of tomato pti4 in arabidopsis. | pti4 is a tomato (lycopersicon esculentum) transcription factor that belongs to the erf (ethylene-responsive element binding factor) family of proteins. it interacts with the pto kinase in tomato, which confers resistance to the pseudomonas syringae pv tomato pathogen that causes bacterial speck disease. to study the function of pti4, transgenic arabidopsis plants were generated that expressed tomato pti4 driven by the strong constitutive promoters, cauliflower mosaic virus 35s and tcup. global ... | 2002 | 11788750 |
| the pseudomonas avrpto protein is differentially recognized by tomato and tobacco and is localized to the plant plasma membrane. | the avrpto gene of pseudomonas syringae pv tomato triggers race-specific resistance in tomato plants carrying pto, a resistance gene encoding a protein kinase. when introduced into p. s. tabaci, avrpto triggers resistance in tobacco w38 plants that carry the corresponding r gene. the avrpto protein is believed to be secreted into host cells through the bacterial type iii secretion pathway, where it activates disease resistance in tomato by interacting with pto. we report here the identification ... | 2000 | 11148281 |
| diversity and molecular evolution of the rps2 resistance gene in arabidopsis thaliana. | the rps2 gene in arabidopsis thaliana governs resistance to strains of the bacterial pathogen, pseudomonas syringae pv. tomato, that express the avrrpt2 gene. the two loci are involved in a gene-for-gene interaction. seventeen accessions of a. thaliana were sequenced to explore the diversity present in the coding region of the rps2 locus. an unusually high level of nucleotide polymorphisms was found (1.26%), with nearly half of the observed polymorphisms resulting in amino acid changes in the rp ... | 1999 | 9874813 |
| benzothiadiazole-induced priming for potentiated responses to pathogen infection, wounding, and infiltration of water into leaves requires the npr1/nim1 gene in arabidopsis. | systemic acquired resistance (sar) is a plant defense state that is induced, for example, after previous pathogen infection or by chemicals that mimic natural signaling compounds. sar is associated with the ability to induce cellular defense responses more rapidly and to a greater degree than in noninduced plants, a process called "priming." arabidopsis plants were treated with the synthetic sar inducer benzothiadiazole (bth) before stimulating two prominent cellular defense responses, namely ph ... | 2002 | 11891259 |
| pseudomonas syringae pv. tomato cells encounter inhibitory levels of water stress during the hypersensitive response of arabidopsis thaliana. | during plant defense against bacterial pathogens, the hypersensitive response (hr) functions to restrict pathogen growth and spread. the mechanisms driving this growth restriction are poorly understood. we used a water stress-responsive transcriptional fusion to quantify the water potential sensed by individual pseudomonas syringae pv. tomato dc3000 cells during infection of arabidopsis thaliana leaves. a nonpathogenic dc3000 hrcc mutant defective in type iii secretion, as well as the saprophyte ... | 2004 | 14981249 |
| the hrp pilus of pseudomonas syringae elongates from its tip and acts as a conduit for translocation of the effector protein hrpz. | the type iii secretion system (ttss) is an essential requirement for the virulence of many gram-negative bacteria infecting plants, animals and man. pathogens use the ttss to deliver effector proteins from the bacterial cytoplasm to the eukaryotic host cell, where the effectors subvert host defences. plant pathogens have to translocate their effector proteins through the plant cell wall barrier. the best candidates for directing effector protein traffic are bacterial appendages attached to the m ... | 2002 | 11953310 |
| age-related resistance in arabidopsis is a developmentally regulated defense response to pseudomonas syringae. | age-related resistance (arr) has been observed in a number of plant species; however, little is known about the biochemical or molecular mechanisms involved in this response. arabidopsis becomes more resistant, or less susceptible, to virulent pseudomonas syringae (pv tomato or maculicola) as plants mature (in planta bacterial growth reduction of 10- to 100-fold). an arr-like response also was observed in response to certain environmental conditions that accelerate arabidopsis development. arr o ... | 2002 | 11884688 |
| peergad: a peer-review-based and community-centric web application for viewing and annotating prokaryotic genome sequences. | peergad is a web-based database-driven application that allows community-wide peer-reviewed annotation of prokaryotic genome sequences. the application was developed to support the annotation of the pseudomonas syringae pv. tomato strain dc3000 genome sequence and is easily portable to other genome sequence annotation projects. peergad incorporates several innovative design and operation features and accepts annotations pertaining to gene naming, role classification, gene translation and annotat ... | 2004 | 15184545 |
| 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 |
| 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 |
| expression of the antiapoptotic baculovirus p35 gene in tomato blocks programmed cell death and provides broad-spectrum resistance to disease. | the sphinganine analog mycotoxin, aal-toxin, induces a death process in plant and animal cells that shows apoptotic morphology. in nature, the aal-toxin is the primary determinant of the alternaria stem canker disease of tomato, thus linking apoptosis to this disease caused by alternaria alternata f. sp. lycopersici. the product of the baculovirus p35 gene is a specific inhibitor of a class of cysteine proteases termed caspases, and naturally functions in infected insects. transgenic tomato plan ... | 2002 | 12403830 |
| pseudomonas type iii effector avrptob induces plant disease susceptibility by inhibition of host programmed cell death. | the avrptob type iii effector protein is conserved among diverse genera of plant pathogens suggesting it plays an important role in pathogenesis. here we report that pseudomonas avrptob acts inside the plant cell to inhibit programmed cell death (pcd) initiated by the pto and cf9 disease resistance proteins and, remarkably, the pro-apoptotic mouse protein bax. avrptob also suppressed pcd in yeast, demonstrating that avrptob functions as a cell death inhibitor across kingdoms. using truncated avr ... | 2003 | 12505984 |
| innate immunity in arabidopsis thaliana: lipopolysaccharides activate nitric oxide synthase (nos) and induce defense genes. | lipopolysaccharides (lps) are cell-surface components of gram-negative bacteria and are microbe-/pathogen-associated molecular patterns in animal pathosystems. as for plants, the molecular mechanisms of signal transduction in response to lps are not known. here, we show that arabidopsis thaliana reacts to lps with a rapid burst of no, a hallmark of innate immunity in animals. fifteen lps preparations (among them burkholderia cepacia, pseudomonas aeruginosa, and erwinia carotovora) as well as lip ... | 2004 | 15498873 |
| 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 |
| hlm1, an essential signaling component in the hypersensitive response, is a member of the cyclic nucleotide-gated channel ion channel family. | the hypersensitive response (hr) in plants is a programmed cell death that is commonly associated with disease resistance. a novel mutation in arabidopsis, hlm1, which causes aberrant regulation of cell death, manifested by a lesion-mimic phenotype and an altered hr, segregated as a single recessive allele. broad-spectrum defense mechanisms remained functional or were constitutive in the mutant plants, which also exhibited increased resistance to a virulent strain of pseudomonas syringae pv toma ... | 2003 | 12566578 |
| npr1 modulates cross-talk between salicylate- and jasmonate-dependent defense pathways through a novel function in the cytosol. | plant defenses against pathogens and insects are regulated differentially by cross-communicating signal transduction pathways in which salicylic acid (sa) and jasmonic acid (ja) play key roles. in this study, we investigated the molecular mechanism of the antagonistic effect of sa on ja signaling. arabidopsis plants unable to accumulate sa produced 25-fold higher levels of ja and showed enhanced expression of the ja-responsive genes lox2, pdf1.2, and vsp in response to infection by pseudomonas s ... | 2003 | 12615947 |
| pto mutants differentially activate prf-dependent, avrpto-independent resistance and gene-for-gene resistance. | pto confers disease resistance to pseudomonas syringae pv tomato carrying the cognate avrpto gene. overexpression of pto under the cauliflower mosaic virus 35s promoter activates spontaneous lesions and confers disease resistance in tomato (lycopersicon esculentum) plants in the absence of avrpto. here, we show that these avrpto-independent defenses require a functional prf gene. several pto-interacting (pti) proteins are thought to play a role in pto-mediated defense pathways. to test if intera ... | 2003 | 12644674 |
| the expression of the t-snare atsnap33 is induced by pathogens and mechanical stimulation. | the fusion of vesicles in the secretory pathway involves the interaction of t-soluble n-ethylmaleimide-sensitive factor attachment protein receptors (t-snares) on the target membrane and v-snares on the vesicle membrane. atsnap33 is an arabidopsis homolog of the neuronal t-snare snap-25 involved in exocytosis and is localized at the cell plate and at the plasma membrane. in this paper, the expression of atsnap33 was analyzed after different biotic and abiotic stresses. the expression of atsnap33 ... | 2003 | 12746539 |
| electrophysiological characterization of the arabidopsis avrrpt2-specific hypersensitive response in the absence of other bacterial signals. | the hypersensitive response (hr) is defined as rapid cell collapse at the infection site and often accompanies plant resistance. the physiological processes leading to hr are not well understood. here, we report an electrophysiological characterization of bacterial hr caused by a single avirulence gene in the absence of other bacterial signals. we used dexamethasone (dex)-inducible transgenic arabidopsis (arabidopsis thaliana) plants containing the avrrpt2 gene from pseudomonas syringae pv tomat ... | 2005 | 15908609 |
| nutritional similarity between leaf-associated nonpathogenic bacteria and the pathogen is not predictive of efficacy in biological control of bacterial spot of tomato. | it has been demonstrated that for a nonpathogenic, leaf-associated bacterium, effectiveness in the control of bacterial speck of tomato is correlated with the similarity in the nutritional needs of the nonpathogenic bacterium and the pathogen pseudomonas syringae pv. tomato. this relationship was investigated further in this study by using the pathogen xanthomonas campestris pv. vesicatoria, the causal agent of bacterial spot of tomato, and a collection of nonpathogenic bacteria isolated from to ... | 2003 | 12788754 |
| systemic acquired tolerance to virulent bacterial pathogens in tomato. | recent studies on the interactions between plants and pathogenic microorganisms indicate that the processes of disease symptom development and pathogen growth can be uncoupled. thus, in many instances, the symptoms associated with disease represent an active host response to the presence of a pathogen. these host responses are frequently mediated by phytohormones. for example, ethylene and salicylic acid (sa) mediate symptom development but do not influence bacterial growth in the interaction be ... | 2005 | 15937273 |
| natural variation in the pto pathogen resistance gene within species of wild tomato (lycopersicon). i. functional analysis of pto alleles. | disease resistance to the bacterial pathogen pseudomonas syringae pv. tomato (pst) in the cultivated tomato, lycopersicon esculentum, and the closely related l. pimpinellifolium is triggered by the physical interaction between plant disease resistance protein, pto, and the pathogen avirulence protein, avrpto. to investigate the extent to which variation in the pto gene is responsible for naturally occurring variation in resistance to pst, we determined the resistance phenotype of 51 accessions f ... | 2005 | 15944360 |
| domain structure of hrpe, the hrp pilus subunit of xanthomonas campestris pv. vesicatoria. | the plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria possesses a type iii secretion (tts) system necessary for pathogenicity in susceptible hosts and induction of the hypersensitive response in resistant plants. this specialized protein transport system is encoded by a 23-kb hrp (hypersensitive response and pathogenicity) gene cluster. x. campestris pv. vesicatoria produces filamentous structures, hrp pili, at the cell surface under hrp-inducing conditions. the hrp pilus acts as ... | 2005 | 16109959 |
| regulation of arabidopsis copine 1 gene expression in response to pathogens and abiotic stimuli. | the copines are a widely distributed class of calcium-dependent, phospholipid-binding proteins of undetermined biological function. mutation of the arabidopsis cpn1 (copine 1) gene causes a humidity-sensitive lesion mimic phenotype with increased resistance to a bacterial and an oomyceteous pathogen, constitutive pathogenesis-related gene expression, and an accelerated hypersensitive cell death defense response. here, we show that the disease resistance phenotype of the cpn1-1 mutant was also te ... | 2003 | 12857819 |
| simultaneous analysis of phytohormones, phytotoxins, and volatile organic compounds in plants. | phytohormones regulate the protective responses of plants against both biotic and abiotic stresses by means of synergistic or antagonistic actions referred to as signaling crosstalk. a bottleneck in crosstalk research is the quantification of numerous interacting phytohormones and regulators. the chemical analysis of salicylic acid, jasmonic acid, indole-3-acetic acid, and abscisic acid is typically achieved by using separate and complex methodologies. moreover, pathogen-produced phytohormone mi ... | 2003 | 12874387 |
| 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 |
| suppression of pathogen-inducible no synthase (inos) activity in tomato increases susceptibility to pseudomonas syringae. | inducible no synthase (inos) activity is induced upon pathogen inoculation in resistant, but not susceptible, tobacco and arabidopsis plants. it was shown recently that a variant form of the arabidopsis p protein (atvarp) has inos activity. p protein is part of the glycine decarboxylase complex (gdc). it is unclear whether p protein also has inos activity and, if so, whether atvarp, p, or both, play a role in plant defense. here, we show that inos activity is induced in both resistant and suscep ... | 2004 | 15146069 |
| genomewide identification of proteins secreted by the hrp type iii protein secretion system of pseudomonas syringae pv. tomato dc3000. | the ability of pseudomonas syringae pv. tomato dc3000 to be pathogenic on plants depends on the hrp (hypersensitive response and pathogenicity) type iii protein secretion system and the effector proteins it translocates into plant cells. through iterative application of experimental and computational techniques, the dc3000 effector inventory has been substantially enlarged. five homologs of known avirulence (avr) proteins and five effector candidates, encoded by genes with putative hrp promoters ... | 2002 | 12032338 |
| 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 |
| protection of tomato seedlings against infection by pseudomonas syringae pv. tomato by using the plant growth-promoting bacterium azospirillum brasilense. | pseudomonas syringae pv. tomato, the causal agent of bacterial speck of tomato, and the plant growth-promoting bacterium azospirillum brasilense were inoculated onto tomato plants, either alone, as a mixed culture, or consecutively. the population dynamics in the rhizosphere and foliage, the development of bacterial speck disease, and their effects on plant growth were monitored. when inoculated onto separate plants, the a. brasilense population in the rhizosphere of tomato plants was 2 orders o ... | 2002 | 12039714 |
| role of salicylic acid and nim1/npr1 in race-specific resistance in arabidopsis. | salicylic acid (sa) and the nim1/npr1 protein have both been demonstrated to be required for systemic acquired resistance (sar) and implicated in expression of race-specific resistance. in this work, we analyzed the role that each of these molecules play in the resistance response triggered by members of two subclasses of resistance (r) genes, members of which recognize unrelated pathogens. we tested the ability of tir and coiled-coil-class (also known as leucine-zipper-class) r genes to confer ... | 2002 | 12072475 |
| characterization of a copper resistance plasmid conserved in copper-resistant strains of pseudomonas syringae pv. tomato. | a 35-kilobase plasmid was conserved among 12 copper-resistant strains of pseudomonas syringae pv. tomato. restriction patterns of this plasmid from each strain were identical, and a cloned copper resistance gene from 1 strain hybridized to the same location on the 35-kilobase plasmid of all 12 strains. | 1987 | 16347294 |
| arabidopsis son1 is an f-box protein that regulates a novel induced defense response independent of both salicylic acid and systemic acquired resistance. | one of several induced defense responses in plants is systemic acquired resistance (sar), which is regulated by salicylic acid and in arabidopsis by the nim1/npr1 protein. to identify additional components of the sar pathway or other genes that regulate sar-independent resistance, we performed genetic suppressor screens of mutagenized nim1-1 seedlings, which are highly susceptible to infection by peronospora parasitica. we isolated the son1 (suppressor of nim1-1) mutant, which shows full restora ... | 2002 | 12119368 |
| 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 |
| vascular associated death1, a novel gram domain-containing protein, is a regulator of cell death and defense responses in vascular tissues. | the hypersensitive response (hr) is a programmed cell death that is commonly associated with plant disease resistance. a novel lesion mimic mutant, vad1 (for vascular associated death1), that exhibits light conditional appearance of propagative hr-like lesions along the vascular system was identified. lesion formation is associated with expression of defense genes, production of high levels of salicylic acid (sa), and increased resistance to virulent and avirulent strains of pseudomonas syringae ... | 2004 | 15269331 |
| 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 |
| the pepper transcription factor capf1 confers pathogen and freezing tolerance in arabidopsis. | an erf/ap2-type transcription factor (capf1) was isolated by differential-display reverse transcription-pcr, following inoculation of the soybean pustule pathogen xanthomonas axonopodis pv glycines 8ra, which induces hypersensitive response in pepper (capsicum annuum) leaves. capf1 mrna was induced under conditions of biotic and abiotic stress. higher levels of capf1 transcripts were observed in disease-resistant tissue compared with susceptible tissue. capf1 expression was additionally induced ... | 2004 | 15347795 |
| genetic elucidation of nitric oxide signaling in incompatible plant-pathogen interactions. | recent experiments indicate that nitric oxide (no) plays a pivotal role in disease resistance and several other physiological processes in plants. however, most of the current information about the function of no in plants is based on pharmacological studies, and additional approaches are therefore required to ascertain the role of no as an important signaling molecule in plants. we have expressed a bacterial nitric oxide dioxygenase (nod) in arabidopsis plants and/or avirulent pseudomonas syrin ... | 2004 | 15347797 |
| variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps) biosynthetic locus in xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice. | in animal pathogenic bacteria, horizontal gene transfer events (hgt) have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (lps). as a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. since lps is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. although lps has been suggested as a ... | 2004 | 15473911 |
| fate of predator and prey proteins during growth of bdellovibrio bacteriovorus on escherichia coli and pseudomonas syringae prey. | a two-dimensional electrophoretic analysis of protein distribution followed by identification of selected proteins by mass spectrometry was performed on fresh bdellovibrio cultures containing attack phase cells of the predatory bacterium bdellovibrio bacteriovorus strain 109j-1 and the remains of an escherichia coli or a pseudomonas syringae pv. tomato prey. cleavage of the peptidoglycan-associated outer membrane proteins (omps) ompa in e. coli and oprf in p. syringae occurred in both prey. the ... | 2005 | 15601717 |
| the hrpk operon of pseudomonas syringae pv. tomato dc3000 encodes two proteins secreted by the type iii (hrp) protein secretion system: hopb1 and hrpk, a putative type iii translocator. | pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type iii protein secretion system (ttss) and the effector proteins it translocates into plant cells for pathogenicity. the p. syringae ttss is encoded by hrp-hrc genes that reside in a central region of a pathogenicity island (pai). flanking one side of this pai is the exchangeable effector locus (eel). we characterized the transcriptional expression of the open reading frames (orfs) within the eel of p. syri ... | 2005 | 15629936 |
| molecular characterization of proteolytic cleavage sites of the pseudomonas syringae effector avrrpt2. | during infection of arabidopsis thaliana, the bacterium pseudomonas syringae pv tomato delivers the effector protein avrrpt2 into the plant cell cytosol. within the plant cell, avrrpt2 undergoes n-terminal processing and causes elimination of arabidopsis rin4. previous work established that avrrpt2 is a putative cysteine protease, and avrrpt2 processing and rin4 elimination require an intact predicted catalytic triad in that avrrpt2. in this work, proteolytic events that depend on avrrpt2 activi ... | 2005 | 15684089 |
| dissecting the beta-aminobutyric acid-induced priming phenomenon in arabidopsis. | plants treated with the nonprotein amino acid beta-aminobutyric acid (baba) develop an enhanced capacity to resist biotic and abiotic stresses. this baba-induced resistance (baba-ir) is associated with an augmented capacity to express basal defense responses, a phenomenon known as priming. based on the observation that high amounts of baba induce sterility in arabidopsis thaliana, a mutagenesis screen was performed to select mutants impaired in baba-induced sterility (ibs). here, we report the i ... | 2005 | 15722464 |
| an arabidopsis homeodomain transcription factor, overexpressor of cationic peroxidase 3, mediates resistance to infection by necrotrophic pathogens. | the mechanisms controlling plant resistance to necrotrophic fungal pathogens are poorly understood. we previously reported on ep5c, a gene shown to be induced by the h(2)o(2) generated during a plant-pathogen interaction. to identify novel plant components operating in pathogen-induced signaling cascades, we initiated a large-scale screen using arabidopsis thaliana plants carrying the beta-glucuronidase reporter gene under control of the h(2)o(2)-responsive ep5c promoter. here, we report the ide ... | 2005 | 15923348 |
| regulation of plant defense responses in arabidopsis by edr2, a ph and start domain-containing protein. | we have identified an arabidopsis mutant that displays enhanced disease resistance (edr2) to the biotrophic powdery mildew pathogen erysiphe cichoracearum. inhibition of fungal growth on edr2 mutant leaves occurred at a late stage of the infection process and coincided with formation of necrotic lesions approximately 5 days after inoculation. double-mutant analysis revealed that edr2-mediated resistance is suppressed by mutations that inhibit salicylic acid (sa)-induced defense signaling, includ ... | 2005 | 16212604 |
| a mutation in the gtp hydrolysis site of arabidopsis dynamin-related protein 1e confers enhanced cell death in response to powdery mildew infection. | we screened for mutants of arabidopsis thaliana that displayed enhanced disease resistance to the powdery mildew pathogen erysiphe cichoracearum and identified the edr3 mutant, which formed large gray lesions upon infection with e. cichoracearum and supported very little sporulation. the edr3-mediated disease resistance and cell death phenotypes were dependent on salicylic acid signaling, but independent of ethylene and jasmonic acid signaling. in addition, edr3 plants displayed enhanced suscept ... | 2006 | 16824181 |
| overexpression of the disease resistance gene pto in tomato induces gene expression changes similar to immune responses in human and fruitfly. | the pto gene encodes a serine/threonine protein kinase that confers resistance in tomato (lycopersicon esculentum) to pseudomonas syringae pv tomato strains that express the type iii effector protein avrpto. constitutive overexpression of pto in tomato, in the absence of avrpto, activates defense responses and confers resistance to several diverse bacterial and fungal plant pathogens. we have used a series of gene discovery and expression profiling methods to examine the effect of pto overexpres ... | 2003 | 12913147 |
| the arabidopsis nhl3 gene encodes a plasma membrane protein and its overexpression correlates with increased resistance to pseudomonas syringae pv. tomato dc3000. | the arabidopsis genome contains a family of ndr1/hin1-like (nhl) genes that show homology to the nonrace-specific disease resistance (ndr1) and the tobacco (nicotiana tabacum) harpin-induced (hin1) genes. nhl3 is a pathogen-responsive member of this nhl gene family that is potentially involved in defense. in independent transgenic nhl3-overexpressing plant lines, a clear correlation between increased resistance to virulent pseudomonas syringae pv. tomato dc3000 and enhanced nhl3 transcript level ... | 2003 | 12913158 |
| the transcriptional innate immune response to flg22. interplay and overlap with avr gene-dependent defense responses and bacterial pathogenesis. | animals and plants carry recognition systems to sense bacterial flagellin. flagellin perception in arabidopsis involves fls2, a leu-rich-repeat receptor kinase. we surveyed the early transcriptional response of arabidopsis cell cultures and seedlings within 60 min of treatment with flg22, a peptide corresponding to the most conserved domain of flagellin. using affymetrix microarrays, approximately 3.0% of 8,200 genes displayed transcript level changes in flg22 elicited suspension cultures and se ... | 2004 | 15181213 |
| conservation of plasmid dna sequences in coronatine-producing pathovars of pseudomonas syringae. | in pseudomonas syringae pv. tomato pt23.2, plasmid ppt23a (101 kb) is involved in synthesis of the phytotoxin coronatine (c. l. bender, d. k. malvick, and r. e. mitchell, j. bacteriol. 171:807-812, 1989). the physical characterization of mutations that abolished coronatine production indicated that at least 30 kb of ppt23a dna are required for toxin synthesis. in the present study, p-labeled dna fragments from the 30-kb region of ppt23a hybridized to plasmid dnas from several coronatine-producin ... | 1991 | 16348476 |
| similarity between copper resistance genes from xanthomonas campestris and pseudomonas syringae. | plasmid-borne copper resistance genes from copper-resistant strains of xanthomonas campestris pv. vesicatoria from california, florida, and oklahoma shared structural similarities. a strain of x. campestris pv. campestris also contained plasmid-borne copper resistance genes similar to the resistance genes from x. campestris pv. vesicatoria. furthermore, a region of the copper resistance genes from x. campestris pv. vesicatoria 07882 hybridized with copa, the first gene of the copper resistance o ... | 1993 | 16348942 |
| comparison of randomly amplified polymorphic dna with amplified fragment length polymorphism to assess genetic diversity and genetic relatedness within genospecies iii of pseudomonas syringae. | recently, dna pairing analyses showed that pseudomonas syringae pv. tomato and related pathovars, including p. syringae pv. maculicola, form a genomic species (pseudomonas tomato) (l. gardan, h. l. shafik, and p. a. d. grimont, p. 445-448, in k. rudolph, t. j. burr, j. w. mansfield, d. stead, a. vivian, and j. von kietzell, ed., pseudomonas syringae pathovars and related pathogens, 1997). the genetic diversity of 23 strains belonging to this genomic species and 4 outgroup strains was analyzed wi ... | 1998 | 16349533 |
| adi3 is a pdk1-interacting agc kinase that negatively regulates plant cell death. | bacterial speck disease in tomato is caused by pseudomonas syringae pv. tomato. resistance to this disease is conferred by the host pto kinase, which recognizes p. s. pv. tomato strains that express the effector avrpto. we report here that an avrpto-dependent pto-interacting protein 3 (adi3) is a member of the agc family of protein kinases. in mammals, agc kinases are regulated by 3-phosphoinositide-dependent protein kinase-1 (pdk1). we characterized tomato pdk1 and showed that pdk1 and pto phos ... | 2006 | 16362044 |
| diverse avrptob homologs from several pseudomonas syringae pathovars elicit pto-dependent resistance and have similar virulence activities. | avrptob is a type iii effector protein from pseudomonas syringae pv. tomato that physically interacts with the tomato pto kinase and, depending on the host genotype, either elicits or suppresses programmed cell death associated with plant immunity. we reported previously that avrptob-related sequences are present in diverse gram-negative phytopathogenic bacteria. here we describe characterization of avrptob homologs from p. syringae pv. tomato t1, pt23, and jl1065, p. syringae pv. syringae b728a ... | 2006 | 16391110 |