| identification of a lysa-like gene required for tabtoxin biosynthesis and pathogenicity in pseudomonas syringae pv. tabaci strain ptbr2.024. | pseudomonas syringae pv. tabaci strain ptbr2.024 produces tabtoxin and causes wildfire disease on tobacco and green bean. ptbr7.000, a tn5 mutant of ptbr2.024, does not produce tabtoxin, is nonpathogenic on tobacco, and is prototrophic. a 3-kb fragment from a genomic library of the parent strain ptbr2.024 complemented both mutant phenotypes. this 3-kb fragment contains two open reading frames (orfs), orf1 and orf2, and two truncated orfs, orf3 and orf4. the tn5 insert in ptbr7.000 was mapped to ... | 1992 | 1515668 |
| [antigenic polysaccharides of bacteria. 37. structure of the polysaccharide chain of pseudomonas syringae pv.tabaci (serogroup vii) lipopolysaccharide]. | the structure of the o-specific polysaccharide chain of pseudomonas syringae pv. tabaci strain 223 (serogroup vii) lipopolysaccharide was established on the basis of one- and two-dimensional 1h nmr analysis, 13c nmr analysis and calculation of optical rotation. the structure determined by the non-destructive way was confirmed by acid hydrolysis and methylation. (sequence: see text). o-antigen of the strain studied is similar in structure and serological properties to o-antigens of pseudomonas sy ... | 1990 | 1693273 |
| somatic antigens of the pseudomonads: structure of the o-specific polysaccharide chain of pseudomonas syringae pv. tabaci 225 (serogroup viii) lipopolysaccharide. | | 1991 | 1720348 |
| biological activities of racemomycin-b, beta-lysine rich streptothricin antibiotic, the main component of streptomyces lavendulae op-2. | racemomycin-b (rm-b), the main component of streptomyces lavendulae op-2 which is the basis of 50% of the antibiotics produced, is a streptothricin antibiotic which contains three beta-lysine moieties in the molecule. rm-b had antimicrobial activity against plant-pathogenic microorganisms and growth-inhibitory activity against the root of brassica rapa l. at the concentration of 50 ppm. it strongly inhibited the growth of pseudomonas syringae pv. tabaci ifo-3508 (minimum inhibitory concentration ... | 1990 | 2177682 |
| the nucleotide sequence of tabtoxin resistance gene (ttr) of pseudomonas syringae pv. tabaci. | | 1990 | 2336364 |
| isolation and characterization of pathogenicity genes of pseudomonas syringae pv. tabaci. | pseudomonas syringae pv. tabaci br2 produces tabtoxin and causes wildfire disease on tobacco and bean plants. approximately 2,700 tn5 insertion mutants of a plasmid-free strain, ptbr 2.024, were generated by using suicide plasmid pgs9. of these tn5 mutants, 8 were no longer pathogenic on tobacco plants and 10 showed reduced symptoms. all of the eight nonpathogenic mutants caused typical wildfire disease symptoms on bean plants. two of the nonpathogenic mutants failed to produce tabtoxin. the eig ... | 1988 | 2836363 |
| self-protection of pseudomonas syringae pv. "tabaci" from its toxin, tabtoxinine-beta-lactam. | an extracellular toxin, tabtoxinine-beta-lactam (t beta l), is produced by pseudomonas syringae pv. "tabaci." this toxin irreversibly inhibits its target, glutamine synthetase; yet p. syringae pv. "tabaci" retains significant amounts of glutamine synthetase activity during toxin production in culture. as part of our investigation of the self-protection of p. syringae pv. "tabaci," we compared the effects of t beta l on tox+ (t beta l-producing, insensitive to t beta l) and tox- (t beta l nonprod ... | 1987 | 3571155 |
| conservation of plasmids among plant-pathogenic pseudomonas syringae isolates of diverse origins. | thirty isolates of pseudomonas syringae pv. tabaci, pv. angulata (pathogens on tobacco), pv. coronafaciens, and pv. striafaciens (pathogens on oats) were examined for plasmid dnas. the strains were obtained from plants throughout the world, some over 50 years ago. of the 22 tobacco pathogens, 16 contain predominantly one type of plasmid, the pjp27.00 type. the remaining six tobacco-specific strains do not harbor detectable plasmids. the oat pathogens contain one, two, or three plasmids. dna homo ... | 1987 | 3628554 |
| expression of the alpha-thionin gene from barley in tobacco confers enhanced resistance to bacterial pathogens. | thionins are cysteine-rich, 5 kda polypeptides which are toxic to plant pathogens in vitro. expression of the gene encoding alpha-thionin from barley endosperm, under the 35s promoter from cauliflower mosaic virus, conferred to transgenic tobacco enhanced resistance to the bacterial plant pathogens pseudomonas syringae pv. tabaci 153 and p. syringae pv. syringae. the barley alpha-thionin gene, which has two introns, was correctly spliced in tobacco. the alpha-thionin in transgenic plants had the ... | 1993 | 8220454 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| the synthesis of tabtoxin peptide bond in pseudomonas syringae pv. tabaci. | | 1998 | 10047897 |
| enhanced resistance to bacterial diseases of transgenic tobacco plants overexpressing sarcotoxin ia, a bactericidal peptide of insect. | sarcotoxin ia is a bactericidal peptide of 39 amino acids found in the common flesh fly, sarcophaga peregrina. many agronomically important bacteria in japan are killed by this peptide at sub-micro molar levels, and the growth of tobacco and rice suspension cultured cells is not inhibited with less than 25 microm. transgenic tobacco plants which overexpress the peptide, i.e. over 250 pmol per gram of fresh leaf, under the control of a high expression constitutive promoter showed enhanced resista ... | 1999 | 10050028 |
| a bean cdna expressed during a hypersensitive reaction encodes a putative calcium-binding protein. | the hypersensitive reaction (hr) is an inducible plant response that is associated with disease resistance. it is characterized by rapid, localized cell death at the site of infection and is believed to inhibit the spread of invading pathogens. we have isolated a cdna clone, designated hra32 (for hypersensitive reaction associated), corresponding to an rna transcript that accumulates in bean during an hr. the predicted protein product of the hra32 cdna is an approximately 17 kda protein of 161 a ... | 1999 | 10432637 |
| conversion of compatible plant-pathogen interactions into incompatible interactions by expression of the pseudomonas syringae pv. syringae 61 hrma gene in transgenic tobacco plants. | the hrma gene from pseudomonas syringae pv. syringae has previously been shown to confer avirulence on the virulent bacterium p. syringae pv. tabaci in all examined tobacco cultivars. we expressed this gene in tobacco plants under the control of the tobacco delta0. 3 tobrb7 promoter, which is induced upon nematode infection in tobacco roots (opperman et al. 1994, science, 263, 221-223). a basal level of hrma expression in leaves of transgenic plants activated the expression of pathogenesis-relat ... | 2000 | 10929114 |
| induced expression of sarcotoxin ia enhanced host resistance against both bacterial and fungal pathogens in transgenic tobacco. | we demonstrate here that induced expression of sarcotoxin ia, a bactericidal peptide from sarcophaga peregrina, enhanced the resistance of transgenic tobacco plants to both bacterial and fungal pathogens. the peptide was produced with a modified pr1a promoter, which is further activated by salicylic acid treatment and necrotic lesion formation by pathogen infection. host resistance to infection of bacteria erwinia carotovora subsp. carotovora and pseudomonas syringae pv. tabaci was shown to be d ... | 2000 | 10939257 |
| the octadecanoid pathway is required for pathogen-induced multi-functional acetyl-coa carboxylase accumulation in common bean (phaseolus vulgaris l.). | a partial cdna clone corresponding to the multi-functional acetyl-coa carboxylase (accase, ec 6.4.1.2) was isolated using rna extracted from methyl jasmonate (meja)-induced common bean cell cultures. most of this clone corresponds to the 3' untranslated region and it showed high identity to alfalfa and soybean accase sequences. southern hybridization revealed one copy of this gene in the common bean genome. in addition to being induced by meja in cell cultures and leaves, accase mrna accumulated ... | 2000 | 10960731 |
| a phaseolus vulgaris lipoxygenase gene expressed in nodules and in rhizobium tropici inoculated roots. | a genomic clone encoding a common bean lipoxygenase (pvlox5) was isolated from a phaseolus vulgaris library. reverse transcription-polymerase chain reaction analysis revealed that pvlox5 is expressed during nodule development and in rhizobium tropici inoculated roots. there was no detectable expression of pvlox5 in non-inoculated roots, healthy leaves, leaves after pseudomonas syringae pv. tabaci infection, floral buds or dry seeds. | 2000 | 11118627 |
| evidence for the involvement of an oxidative stress in the initiation of infection of pear by erwinia amylovora. | involvement of an oxidative burst, usually related to incompatible plant/pathogen interactions leading to hypersensitive reactions, was investigated with erwinia amylovora, the causal agent of fire blight of maloideae subfamily of rosaceae, in interaction with pear (pyrus communis; compatible situation) and tobacco (nicotiana tabacum; incompatible situation). as expected, this necrogenic bacterium induced in tobacco a sustained production of superoxide anion, lipid peroxidation, electrolyte leak ... | 2001 | 11299395 |
| broad-spectrum antimicrobial activity in vitro of the synthetic peptide d4e1. | broad-spectrum antimicrobial activity of a synthetic peptide, d4e1, is documented in this paper. d4e1 inhibited the growth of several fungal phytopathogens belonging to four classes-ascomycetes, basidiomycetes, deuteromycetes, and oomycetes, and two bacterial pathogens, pseudomonas syringae pv. tabaci and xanthomonas campestris pv. malvacearum race 18. the minimum inhibitory concentration (mic) of d4e1 required to completely inhibit the growth of all fungi studied ranged from 4.67 to 25 microm. ... | 2001 | 11409968 |
| crystallization and preliminary x-ray crystallographic analysis of native and selenomethionyl recombinant tabtoxin-resistance protein complexed with acetyl-coenzyme a. | tabtoxin-resistance protein (ttr), an acetyltransferase from pseudomonas syringae pv. tabaci, was overexpressed in eschericha coli m15 and the ttr fusion protein complexed with acetyl-coenzyme a (accoa) was purified and crystallized. diffraction data were collected to 3.0 a resolution in-house and the crystal was found to belong to space group p2(1), with unit-cell parameters a = 47.6, b = 66.6, c = 53.5 a, beta = 104.3 degrees. furthermore, a selenomethionine (semet) ttr fusion protein derivati ... | 2001 | 11679759 |
| expression of an antimicrobial peptide via the chloroplast genome to control phytopathogenic bacteria and fungi. | the antimicrobial peptide msi-99, an analog of magainin 2, was expressed via the chloroplast genome to obtain high levels of expression in transgenic tobacco (nicotiana tabacum var. petit havana) plants. polymerase chain reaction products and southern blots confirmed integration of msi-99 into the chloroplast genome and achievement of homoplasmy, whereas northern blots confirmed transcription. contrary to previous predictions, accumulation of msi-99 in transgenic chloroplasts did not affect norm ... | 2001 | 11706168 |
| tabtoxin-resistant protein: overexpression, purification, and characterization. | one of the self-protection mechanisms in pseudomonas syringae pv. tabaci, a pathogen of tobacco wildfire, is thought to be due to its tabtoxin-resistance gene (ttr). in this study, the ttr gene was inserted into an expression vector, pqe30, and successfully expressed in escherichia coli m15 at high levels. the purified recombinant tabtoxin-resistant protein (ttr) had an apparent molecular mass of about 21 kda on sds-page as well as by mass spectroscopy and had a pi of 6.6 on isoelectric focusing ... | 2002 | 11922760 |
| constitutive expression of hrap gene in transgenic tobacco plant enhances resistance against virulent bacterial pathogens by induction of a hypersensitive response. | hypersensitive response-assisting protein (hrap) has been previously reported as an amphipathic plant protein isolated from sweet pepper that intensifies the harpin(pss)-mediated hypersensitive response (hr). the hrap gene has no appreciable similarity to any other known sequences, and its activity can be rapidly induced by incompatible pathogen infection. to assess the function of the hrap gene in plant disease resistance, the camv 35s promoter was used to express sweet pepper hrap in transgeni ... | 2002 | 12182333 |
| a strobilurin fungicide enhances the resistance of tobacco against tobacco mosaic virus and pseudomonas syringae pv tabaci. | the strobilurin class of fungicides comprises a variety of synthetic plant-protecting compounds with broad-spectrum antifungal activity. in the present study, we demonstrate that a strobilurin fungicide, f 500 (pyraclostrobin), enhances the resistance of tobacco (nicotiana tabacum cv xanthi nc) against infection by either tobacco mosaic virus (tmv) or the wildfire pathogen pseudomonas syringae pv tabaci. f 500 was also active at enhancing tmv resistance in nahg transgenic tobacco plants unable t ... | 2002 | 12226492 |
| water relation alterations observed during hypersensitive reaction induced by bacteria. | upon exposure to pathogenic bacteria, resistant and nonhost plants undergo a hypersensitive reaction (hr) that is expressed as rapid plant cell death. if sufficient concentrations of these bacteria are inoculated to such plant tissue, then that portion of the tissue rapidly collapses and becomes necrotic. as the tissue collapses the water relations of inoculated tissues become markedly disturbed. we measured a decline in the relative water content (rwc) in the leaf-like cotyledons of cotton (gos ... | 1993 | 12232016 |
| 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 |
| generalized induction of defense responses in bean is not correlated with the induction of the hypersensitive reaction. | transcripts for phenylalanine ammonia-lyase, chalcone synthase, chalcone isomerase, and chitinase accumulated in common bean after infiltration with the pseudomonas syringae pv tabaci hrp- mutant pt11528::hrp1, even though a hypersensitive reaction did not occur. the temporal pattern of this transcript accumulation was similar to that seen after infiltration with wild-type p. s. tabaci pt11528, which resulted in a hypersensitive reaction. escherichia coli dh5[alpha], p. fluorescens pf101, heat-k ... | 1993 | 12271015 |
| effects of nutritional factors on production of tabtoxin, a phytotoxin, by pseudomonas syringae pv. tabaci. | pseudomonas syringae pv. tabaci, the causal agent of the wildfire of tobacco, produces the phytotoxin tabtoxin. the effects of carbon, nitrogen sources and amino acids on growth and tabtoxin production by pv. tabaci, were examined by varying the components of a defined basal medium, which contained the following nutrients per liter: sucrose (10 g), kno3 (5 g), mgso(4).7h2o (0.2 g), cacl(2).2h2o (0.11 g), feso(4).7h2o (20 mg), nah2po(4).2h2o (0.9 g) and h2po(4).3ho (1 g). bacterial growth was det ... | 2001 | 12425044 |
| modulation of defense responses of malus spp. during compatible and incompatible interactions with erwinia amylovora. | erwinia amylovora is the causal agent of fire blight, a disease affecting members of subfamily maloideae. in order to analyze mechanisms leading to compatible or incompatible interactions, early plant molecular events were investigated in two genotypes of malus with contrasting susceptibility to fire blight, after confrontation with either e. amylovora or the incompatible tobacco pathogen pseudomonas syringae pv. tabaci. many defense mechanisms, including generation of an oxidative burst and acc ... | 2002 | 12481992 |
| brassinosteroid functions in a broad range of disease resistance in tobacco and rice. | brassinolide (bl), considered to be the most important brassinosteroid (br) and playing pivotal roles in the hormonal regulation of plant growth and development, was found to induce disease resistance in plants. to study the potentialities of bl activity on stress responding systems, we analyzed its ability to induce disease resistance in tobacco and rice plants. wild-type tobacco treated with bl exhibited enhanced resistance to the viral pathogen tobacco mosaic virus (tmv), the bacterial pathog ... | 2003 | 12609030 |
| the deltaflid mutant of pseudomonas syringae pv. tabaci, which secretes flagellin monomers, induces a strong hypersensitive reaction (hr) in non-host tomato cells. | to investigate the role of flagella and monomer flagellin in the interaction between pseudomonas syringae pv. tabaci and plants, non-polar flic and flid mutants were produced. the orfs for flic and flid are deleted in the deltaflic and deltaflid mutants, respectively. both mutants lost all flagella and were non-motile. the deltaflic mutant did not produce flagellin, whereas the deltaflid mutant, which lacks the hap2 protein, secreted large amounts of monomer flagellin into the culture medium. in ... | 2003 | 12715150 |
| activation of defense-related gene expression and systemic acquired resistance in cucumber mosaic virus-infected tobacco plants expressing the mammalian 2'5'oligoadenylate system. | tobacco plants expressing the mammalian 2'5'oligoadenylate system (2-5a system) exhibit resistance to cucumber mosaic virus (cmv). here, to characterize the molecular aspect of the resistance to cmv in 2-5a system-expressing tobaccos, the activation of defense-related genes and systemic acquired resistance (sar) as the markers for the hypersensitive resistance (hr), were elucidated. northern hybridization analysis indicated that the expression of four pathogenesis-related (pr) protein genes and ... | 2003 | 12721807 |
| characterization of a pathogen-induced calmodulin-binding protein: mapping of four ca2+-dependent calmodulin-binding domains. | ca2+ and calmodulin (cam), a key ca2+ sensor in all eukaryotes, have been implicated in defense responses in plants. to elucidate the role of ca2+ and cam in defense signaling, we used 35s-labeled cam to screen expression libraries prepared from tissues that were either treated with an elicitor derived from phytophthora megasperma or infected with pseudomonas syringae pv. tabaci. nineteen cdnas that encode the same protein, pathogen-induced cam-binding protein (picbp), were isolated. the picbp f ... | 2003 | 12825696 |
| flagellin glycosylation island in pseudomonas syringae pv. glycinea and its role in host specificity. | the deduced amino acid sequences of the flagellins of pseudomonas syringae pv. tabaci and p. syringae pv. glycinea are identical; however, their abilities to induce a hypersensitive reaction are clearly different. the reason for the difference seems to depend on the posttranslational modification of the flagellins. to investigate the role of this posttranslational modification in the interactions between plants and bacterial pathogens, we isolated genes that are potentially involved in the postt ... | 2003 | 14594840 |
| identification of an antibacterial compound, benzylideneacetone, from xenorhabdus nematophila against major plant-pathogenic bacteria. | an entomopathogenic bacterium, xenorhabdus nematophila, is known to have potent antibiotic activities to maintain monoxenic condition in its insect host for effective pathogenesis and ultimately for optimal development of its nematode symbiont, steinernema carpocapsae. in this study we assess its antibacterial activity against plant-pathogenic bacteria and identify its unknown antibiotics. the bacterial culture broth had significant antibacterial activity that increased with development of the b ... | 2004 | 15476972 |
| overexpression of the ap2/erebp transcription factor opbp1 enhances disease resistance and salt tolerance in tobacco. | osmotin promoter binding protein 1 (opbp1), an ap2/erebp-like transcription factor of tobacco (nicotiana tabacum), was isolated using a yeast one-hybrid system. rna gel blot analysis indicated that expression of the opbp1 gene was induced by elicitor cryptogein, nacl, ethephon, methyl jasmonate, as well as cycloheximide. transient expression analysis using an opbp1-egfp fusion gene in onion epidermal cells revealed that the opbp1 protein was targeted to the nuclear. further, electrophoretic mobi ... | 2004 | 15604704 |
| identification of pathogen-responsive regions in the promoter of a pepper lipid transfer protein gene (caltpi) and the enhanced resistance of the caltpi transgenic arabidopsis against pathogen and environmental stresses. | the 5' flanking region of the caltpi gene, which encodes a basic lipid transfer protein, was isolated and characterized from the genomic dna of capsicum annuum. four different regions of the promoter sequence of the caltpi gene were fused to the beta-glucuronidase (gus) coding region. in an agrobacterium-mediated transient expression assay, the transcriptional activations of the promoter deletions were examined in tobacco leaves after infection with pseudomonas syringae pv. tabaci, and treatment ... | 2005 | 15654638 |
| pest and disease resistance enhanced by heterologous suppression of a nicotiana plumbaginifolia cytochrome p450 gene cyp72a2. | the functional role of the nicotiana plumbaginifolia cytochrome p450 gene cyp72a2 was investigated in transgenic plants. n. tabacum plants transformed with a sense or antisense cyp72a2 construct exhibited diminished heights, branched stems, smaller leaves and deformed flowers. western blot analysis revealed reduced levels of a 58 kda protein corresponding to cyp72a2, suggesting that the cyp72a2 homolog was suppressed in the sense and antisense plants. transgenic plants had increased resistance t ... | 2004 | 15672219 |
| overexpression of a pepper basic pathogenesis-related protein 1 gene in tobacco plants enhances resistance to heavy metal and pathogen stresses. | a pepper gene, cabpr1, which encodes basic pathogenesis-related protein 1, has been reported to be strongly induced after ethephon treatment, wounding, and tobacco mosaic virus infection. the potential role of cabpr1 in tolerance of biotic or abiotic stresses was examined in transgenic nicotiana tabacum cv. xanthi plants. overexpression of cabpr1 in tobacco plants enhanced tolerance not only to heavy metal stresses, but also to the oomycete pathogen phytophthora nicotianae, and the bacterial pat ... | 2005 | 15719238 |
| molecular genetic evidence for the role of sgt1 in the intramolecular complementation of bs2 protein activity in nicotiana benthamiana. | pepper plants (capsicum annuum) containing the bs2 resistance gene are resistant to strains of xanthomonas campestris pv vesicatoria (xcv) expressing the bacterial effector protein avrbs2. avrbs2 is delivered directly to the plant cell via the type iii protein secretion system (ttss) of xcv. upon recognition of avrbs2 by plants expressing the bs2 gene, a signal transduction cascade is activated leading to a bacterial disease resistance response. here, we describe a novel pathosystem that consist ... | 2005 | 15749757 |
| activation of pepper basic pr-1 gene promoter during defense signaling to pathogen, abiotic and environmental stresses. | the basic pr-1 gene, cabpr1, accumulates in pepper leaf tissues during pathogen infection as well as after ethylene treatment. we isolated and functionally characterized the cabpr1 promoter region in tobacco leaves to identify the cis-acting regulatory sequences that are involved in cabpr1 gene expression. constructs harboring the 5'-serially deleted cabpr1 promoter, which was fused to the beta-glucuronidase (gus) gene, were evaluated for their promoter activity in the tobacco leaves. the cabpr1 ... | 2005 | 16005163 |
| nppdr1, a pleiotropic drug resistance-type atp-binding cassette transporter from nicotiana plumbaginifolia, plays a major role in plant pathogen defense. | nicotiana plumbaginifolia nppdr1, a plasma membrane pleiotropic drug resistance-type atp-binding cassette transporter formerly named npabc1, has been suggested to transport the diterpene sclareol, an antifungal compound. however, direct evidence for a role of pleiotropic drug resistance transporters in the plant defense is still lacking. in situ immunolocalization and histochemical analysis using the gusa reporter gene showed that nppdr1 was constitutively expressed in the whole root, in the lea ... | 2005 | 16126865 |
| promoter activation of pepper class ii basic chitinase gene, cachi2, and enhanced bacterial disease resistance and osmotic stress tolerance in the cachi2-overexpressing arabidopsis. | the activation of the cachi2 promoter as the result of bacterial infection and osmotic stresses was examined using the agrobacterium-mediated transient expression assay. several stress-related cis-acting elements were revealed within the upstream genomic sequence of the cachi2 gene. in tobacco leaf tissues transiently transformed with the cachi2 promoter-beta-glucuronidase (gus) gene, the cachi2 promoter was up-regulated by pseudomonas syringae pv. tabaci infection. the cachi2-gus activation was ... | 2006 | 16151843 |
| production of an engineered killer peptide in nicotiana benthamiana by using a potato virus x expression system. | the decapeptide killer peptide (kp) derived from the sequence of a single-chain, anti-idiotypic antibody acting as a functional internal image of a microbicidal, broad-spectrum yeast killer toxin (kt) was shown to exert a strong microbicidal activity against human pathogens. with the aim to exploit this peptide to confer resistance to plant pathogens, we assayed its antimicrobial activity against a broad spectrum of phytopathogenic bacteria and fungi. synthetic kp exhibited antimicrobial activit ... | 2005 | 16204558 |
| identification and deletion analysis of the promoter of the pepper sar8.2 gene activated by bacterial infection and abiotic stresses. | the pepper sar8.2 gene, casar82a, was locally and systemically induced in pepper plants which had been infected by xanthomonas campestris pv. vesicatoria or by pseudomonas fluorescens. the dna 1,283 bp sequence upstream of the casar82a gene was assessed with regard to the activity of the casar82a promoter fused to the beta-glucuronidase (gus) reporter gene, via an agrobacterium-mediated transient expression assay. in tobacco leaves which transiently expressed the -831 bp casar82a promoter, gus a ... | 2006 | 16395580 |
| novel extracellular chitinases rapidly and specifically induced by general bacterial elicitors and suppressed by virulent bacteria as a marker of early basal resistance in tobacco. | early basal resistance (ebr, formerly known as early induced resistance) is triggered by general bacterial elicitors. ebr has been suggested to inhibit or retard expression of the type iii secretion system of pathogenic bacteria and may also prevent nonpathogenic bacteria from colonizing the plant tissue. the quickness of ebr here plays a crucial role, compensating for a low bactericidal efficacy. this inhibitory activity should take place in the cell wall, as bacteria do not enter living plant ... | 2006 | 16529378 |
| comparative analysis of induction pattern of programmed cell death and defense-related responses during hypersensitive cell death and development of bacterial necrotic leaf spots in eggplant. | pseudomonas cichorii causes necrotic leaf spots (nls), while pseudomonas syringae pv. tabaci induces a hypersensitive response (hr) in eggplant. p. cichorii induced cell death at 9 h after inoculation (hai), reaching a maximum of around 24-30 hai. on the other hand, cell death was induced 6 hai with p. syringae pv. tabaci, reaching a maximum of around 12-18 hai. superoxide generation was observed in eggplant inoculated with both bacteria. dna fragmentation, cytochrome c release into the cytosol ... | 2006 | 16614819 |
| inhibition of glutamine synthetase from pea by tabtoxinine-beta-lactam. | tabtoxinine-beta-lactam, a hydrolytic product of tabtoxin produced by pseudomonas syringae pv. tabaci, apparently inactivates pea seed glutamine synthetase. inhibition of the enzyme's initial velocity is linear over a range of 0.5 to 5 millimolar tabtoxinine-beta-lactam in the presence of 10 millimolar glutamate. a method for the purification of glutamine synthetase from dried peas is presented which gives a 30% yield with a 2,000-fold increase in specific activity. a method for obtaining highly ... | 1983 | 16662928 |
| inactivation of glutamine synthetase by tabtoxinine-beta-lactam : effects of substrates and ph. | the inactivation of glutamine synthetase by tabtoxinine-beta-lactam, a phytotoxin produced by pseudomonas syringae pv. tabaci, was shown to be irreversible. the chloroplast and cytosolic forms of the enzyme from pea leaves (pisum sativum l.) were separated, purified, and found to be kinetically similar with k(m) values for glutamate of 6.7 and 4.3 millimolar and for atp of 2.0 and 1.3 millimolar, respectively. both forms were irreversibly inactivated by the toxin at equal rates. using the chloro ... | 1984 | 16663826 |
| effects of tabtoxinine-beta-lactam on nitrogen metabolism in avena sativa l. roots. | the effects of tabtoxinine-beta-lactam (t-beta-l) on nitrate uptake and glutamine synthetase (gs) and nitrate reductase (nr) activities in roots of avena sativa seedlings were determined. seven-day-old oat seedlings placed in a 10 mm kno(3) and 0.5 mm t-beta-l solution for 24 hours took up t-beta-l and lost approximately 90% of their root gs activity. [(3)h]-t-beta-l taken up by roots of seven-day-old oat seedlings was associated with gs immunoprecipitated from the extract of these roots. total ... | 1986 | 16665133 |
| oats tolerant of pseudomonas syringae pv. tabaci contain tabtoxinine-beta-lactam-insensitive leaf glutamine synthetases. | pseudomonas syringae pv. tabaci, a commonly recognized leaf pathogen of tobacco, can infest the rhizosphere of many plants, including oats. normal oat plants do not survive this infestation as a consequence of the complete and irreversible inactivation of all of their glutamine synthetases by tabtoxinine-beta-lactam (tbetal), a toxin released by pv. tabaci. we have identified a population of oat (avena sativa l. var lodi) plants that are tolerant of pv. tabaci. the tolerant plants had no detecta ... | 1988 | 16666304 |
| xylanase, a novel elicitor of pathogenesis-related proteins in tobacco, uses a non-ethylene pathway for induction. | antisera to acidic isoforms of pathogenesis-related proteins were used to measure the induction of these proteins in tobacco (nicotiana tabacum) leaves. endo-(1-4)-beta-xylanase purified from culture filtrates of trichoderma viride was a strong elicitor of pathogenesis-related protein synthesis in tobacco leaves. the synthesis of these proteins was localized to tissue at the area of enzyme application. the inhibitors of ethylene biosynthesis and ethylene action, 1-aminoethoxyvinylglycine and sil ... | 1990 | 16667541 |
| identification of glycosylation genes and glycosylated amino acids of flagellin in pseudomonas syringae pv. tabaci. | a glycosylation island is a genetic region required for glycosylation. the glycosylation island of flagellin in pseudomonas syringae pv. tabaci 6605 consists of three orfs: orf1, orf2 and orf3. orf1 and orf2 encode putative glycosyltransferases, and their deletion mutants, deltaorf1 and deltaorf2, exhibit deficient flagellin glycosylation or produce partially glycosylated flagellin respectively. digestion of glycosylated flagellin from wild-type bacteria and non-glycosylated flagellin from delta ... | 2006 | 16681835 |
| overexpression of gberf confers alteration of ethylene-responsive gene expression and enhanced resistance to pseudomonas syringae in transgenic tobacco. | gberf belongs to the erf (ethylene responsive factor) family of transcription factors and regulates the gcc-box containing pathogen-related (pr) genes in the ethylene signal transduction pathway. to study the function of gberf in the process of biotic stress, transgenic tobacco plants expressing gberf were generated. overexpression of gberf did not change transgenic plant's phenotype and endogenous ethylene level. however, the expression profile of some ethylene-inducible gcc-box and non-gcc-box ... | 2006 | 16809858 |
| gacs-dependent production of 2r, 3r-butanediol by pseudomonas chlororaphis o6 is a major determinant for eliciting systemic resistance against erwinia carotovora but not against pseudomonas syringae pv. tabaci in tobacco. | root colonization by a plant-beneficial rhizobacterium, pseudomonas chlororaphis o6, induces disease resistance in tobacco against leaf pathogens erwinia carotovora subsp. carotovora scc1, causing soft-rot, and pseudomonas syringae pv. tabaci, causing wildfire. in order to identify the bacterial determinants involved in induced systemic resistance against plant diseases, extracellular components produced by the bacterium were fractionated and purified. factors in the culture filtrate inducing sy ... | 2006 | 16903358 |
| aconitase plays a role in regulating resistance to oxidative stress and cell death in arabidopsis and nicotiana benthamiana. | in animals, aconitase is a bifunctional protein. when an iron-sulfur cluster is present in its catalytic center, aconitase displays enzymatic activity; when this cluster is lost, it switches to an rna-binding protein that regulates the translatability or stability of certain transcripts. to investigate the role of aconitase in plants, we assessed its ability to bind mrna. recombinant aconitase failed to bind an iron responsive element (ire) from the human ferritin gene. however, it bound the 5' ... | 2007 | 17013749 |
| a homologue of the 3-oxoacyl-(acyl carrier protein) synthase iii gene located in the glycosylation island of pseudomonas syringae pv. tabaci regulates virulence factors via n-acyl homoserine lactone and fatty acid synthesis. | pseudomonas syringae pv. tabaci 6605 possesses a genetic region involved in flagellin glycosylation. this region is composed of three open reading frames: orf1, orf2, and orf3. our previous study revealed that orf1 and orf2 encode glycosyltransferases; on the other hand, orf3 has no role in posttranslational modification of flagellin. although the function of orf3 remained unclear, an orf3 deletion mutant (deltaorf3 mutant) had reduced virulence on tobacco plants. orf3 shows significant homology ... | 2006 | 17028280 |
| cladosporium fulvum cfhnni1 induces hypersensitive necrosis, defence gene expression and disease resistance in both host and nonhost plants. | nonhost resistance as a durable and broad-spectrum defence strategy is of great potential for agricultural applications. we have previously isolated a cdna showing homology with genes encoding bzip transcription factors from tomato leaf mould pathogen cladosporium fulvum. upon expression, the cdna results in necrosis in c. fulvum host tomato and nonhost tobacco plants and is thus named cfhnni1 (for c . f ulvum host and nonhost plant necrosis inducer 1). in the present study we report the inducti ... | 2007 | 17273821 |
| over-expression gberf2 transcription factor in tobacco enhances brown spots disease resistance by activating expression of downstream genes. | erf transcription factors can bind gcc boxes or non-gcc cis elements to regulate biotic and abiotic stress responses. here, we report that an erf transcription factor gene (gberf2) was cloned by suppression subtraction hybridization from sea-island cotton after verticillium dahliae attack. the gberf2 cdna has a total length of 1143 bp with an open reading frame of 597 bp. the genomic sequence of gberf2 contains an intron of 515 bp. the gene encodes a predicated polypeptide of 198 amino acids wit ... | 2007 | 17321073 |
| flagellin glycans from two pathovars of pseudomonas syringae contain rhamnose in d and l configurations in different ratios and modified 4-amino-4,6-dideoxyglucose. | flagellins from pseudomonas syringae pv. glycinea race 4 and pseudomonas syringae pv. tabaci 6605 have been found to be glycosylated. glycosylation of flagellin is essential for bacterial virulence and is also involved in the determination of host specificity. flagellin glycans from both pathovars were characterized, and common sites of glycosylation were identified on six serine residues (positions 143, 164, 176, 183, 193, and 201). the structure of the glycan at serine 201 (s201) of flagellin ... | 2007 | 17644592 |
| functional analysis of the role of fur in the virulence of pseudomonas syringae pv. tabaci 11528: fur controls expression of genes involved in quorum-sensing. | in most bacteria, fur (ferric uptake regulator) is a crucial global regulator known to operate not only in the regulation of iron homeostasis but also in a variety of other cellular processes. in an effort to characterize the role of fur in the virulence of plant pathogens, a fur homolog was isolated from pseudomonas syringae pv. tabaci 11528. phenotype assays showed that a fur deletion mutant (bl33) constitutively produced siderophore(s) and exhibited decreases in swarming motility as well as t ... | 2008 | 18023417 |
| effects of glycosylation on swimming ability and flagellar polymorphic transformation in pseudomonas syringae pv. tabaci 6605. | the role of flagellin glycosylation on motility was investigated in pseudomonas syringae pv. tabaci. the swimming activity of glycosylation-defective mutants was prominently decreased in a highly viscous medium. the mutants showed differences in polymorphic transitions and in the bundle formation of flagella, indicating that glycosylation stabilizes the filament structure and lubricates the rotation of the bundle. | 2008 | 18024523 |
| gac two-component system in pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction. | pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. to investigate the regulatory mechanism of the expression of virulence, gac two-component system-defective mutants, deltagaca and deltagacs, and a double mutant, deltagacadeltagacs, were generated. these mutants produced smaller amounts of n-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algt gene required for ex ... | 2008 | 18080141 |
| modulation of defense signal transduction by flagellin-induced wrky41 transcription factor in arabidopsis thaliana. | flagellin, a component of the flagellar filament of pseudomonas syringae pv. tabaci 6605 (pta), induces hypersensitive reaction in its non-host arabidopsis thaliana. we identified the wrky41 gene, which belongs to a multigene family encoding wrky plant-specific transcription factors, as one of the flagellin-inducible genes in a. thaliana. expression of wrky41 is induced by inoculation with the incompatible pathogen p. syringae pv. tomato dc3000 (pto) possessing avrrpt2 and the non-host pathogens ... | 2008 | 18219494 |
| the f-box protein acre189/acif1 regulates cell death and defense responses activated during pathogen recognition in tobacco and tomato. | virus-induced gene silencing identified the avr9/cf-9 rapidly elicited gene acre189 as essential for the cf-9- and cf-4-mediated hypersensitive response (hr) in nicotiana benthamiana. we report a role for acre189 in disease resistance in tomato (solanum lycopersicum) and tobacco (nicotiana tabacum). acre189 (herein renamed avr9/cf-9-induced f-box1 [acif1]) encodes an f-box protein with a leu-rich-repeat domain. acif1 is widely conserved and is closely related to f-box proteins regulating plant h ... | 2008 | 18375657 |
| functional analysis reveals pleiotropic effects of rice ring-h2 finger protein gene osbirf1 on regulation of growth and defense responses against abiotic and biotic stresses. | ring finger proteins comprise a large family and play key roles in regulating growth/developmental processes, hormone signaling and responses to biotic and abiotic stresses in plants. a rice gene, osbirf1, encoding a putative ring-h2 finger protein, was cloned and identified. osbirf1 encodes a 396 amino acid protein belonging to the atl family characterized by a conserved ring-h2 finger domain (c-x2-c-x15-c-x1-h-x2-h-x2-c-x10-c-x2-c), a transmembrane domain at the n-terminal, a basic amino acid ... | 2008 | 18496756 |
| overexpression of a rice defense-related f-box protein gene osdrf1 in tobacco improves disease resistance through potentiation of defense gene expression. | f-box proteins play important roles in plant growth/development and responses to environmental stimuli through targeting substrates into degradation machinery. a rice defense-related f-box protein gene, osdrf1, was cloned and identified during a course of study aimed at elucidating the molecular basis of induced immunity in rice. osdrf1 encodes a protein of 328 amino acids, containing a highly conserved f-box domain. expression of osdrf1 was induced upon treatment with benzothiadiazole (bth), a ... | 2008 | 18573188 |
| amino acid sequence of bacterial microbe-associated molecular pattern flg22 is required for virulence. | flagellin proteins derived from pseudomonas syringae pv. tabaci 6605 and flg22pa (qrlstgsrinsakddaaglqia), one of the microbe-associated molecular patterns (mamp) in bacterial flagellin, induce cell death and growth inhibition in arabidopsis thaliana. to examine the importance of aspartic acid (d) at position 43 from the n-terminus of a flagellin in its elicitor activity, d43 was replaced with valine (v) and alanine (a) in p. syringae pv. tabaci flagellin and flg22pta. the abilities of flagellin ... | 2008 | 18700821 |
| role of a xyloglucan-specific endo-beta-1,4-glucanase inhibitor in the interactions of nicotiana benthamiana with colletotrichum destructivum, c. orbiculare or pseudomonas syringae pv. tabaci. | a xyloglucan-specific endo-beta-1,4-glucanase inhibitor cdna, nbxegip1, was amplified from diseased leaves of nicotiana benthamiana. the sequence was similar to the tomato xyloglucan-specific endo-beta-1,4-glucanase inhibitor (xegip) and tobacco nectarin iv genes that have been described as binding and inactivating fungal family 12 xyloglucan-specific endo-beta-1,4-glucanases. expression of nbxegip1 was not detected in healthy leaves, but the gene was induced during the later stages of infection ... | 2008 | 18705851 |
| high-throughput in planta expression screening identifies an adp-ribosylation factor (arf1) involved in non-host resistance and r gene-mediated resistance. | to identify positive regulators of cell death in plants, we performed a high-throughput screening, employing potato virus x-based overexpression in planta of a cdna library derived from paraquat-treated nicotiana benthamiana leaves. the screening of 30,000 cdna clones enabled the identification of an adp-ribosylation factor 1 (arf1) that induces cell death when overexpressed in n. benthamiana. overexpression of the guanosine diphosphate (gdp)-locked mutant of arf1 did not trigger cell death, sug ... | 2008 | 18705881 |
| ntbzip60, an endoplasmic reticulum-localized transcription factor, plays a role in the defense response against bacterial pathogens in nicotiana tabacum. | a spermine-based signal transduction pathway plays a defensive role against incompatible pathogens. we identified a novel spermine-responsive cdna from nicotiana tabacum that encodes a basic region/leucine zipper protein with a putative transmembrane domain. identity to arabidopsis thaliana atbzip60 was sufficiently high to name the novel cdna ntbzip60. expression analysis revealed that ntbzip60 is a component of the spermine-signal pathway, and is also involved in the unfolded protein response ... | 2008 | 18758894 |
| expression and functional characterization of the plant antimicrobial snakin-1 and defensin recombinant proteins. | in this study, for the first time, functionally active, recombinant, cysteine-rich plant proteins snakin-1 (sn1) and defensin (pth1) were expressed and purified using a prokaryotic expression system. the overall level of antimicrobial activities of sn1 and pth1 produced in escherichia coli was commensurate with that of the same proteins previously obtained from plant tissues. both proteins exhibited strong antibacterial activity against the phytopathogenic bacterium clavibacter michiganensis sub ... | 2009 | 18824107 |
| the promoter of the pepper pathogen-induced membrane protein gene capimp1 mediates environmental stress responses in plants. | the promoter of the pepper pathogen-induced membrane protein gene capimp1 was analyzed by an agrobacterium-mediated transient expression assay in tobacco leaves. several stress-related cis-acting elements (gt-1, w-box and abre) are located within the capimp1 promoter. in tobacco leaf tissues transiently transformed with a capimp1 promoter-beta-glucuronidase (gus) gene fusion, serially 5'-deleted capimp1 promoters were differentially activated by pseudomonas syringae pv. tabaci, ethylene, methyl ... | 2009 | 18936963 |
| a promoter from pea gene drr206 is suitable to regulate an elicitor-coding gene and develop disease resistance. | abstract plant nonhost disease resistance is characterized by the induction of multiple defense genes. the pea drr206 gene is induced following inoculation with pathogens and treatment with abiotic agents, and moderately induced by wounding. a deletion series of drr206 promoter segments was fused with the beta-glucuronidase (gus) reporter gene and transiently transferred to tobacco, potato, and pea. gus activity revealed that two upstream regions of the drr206 promoter were particularly importan ... | 2004 | 18943490 |
| expression of an engineered cecropin gene cassette in transgenic tobacco plants confers disease resistance to pseudomonas syringae pv. tabaci. | abstract a chimeric gene fusion cassette, consisting of a secretory sequence from barley alpha-amylase joined to a modified cecropin (mb39) coding sequence and placed under control of the promoter and terminator from the potato proteinase inhibitor ii (piii) gene, was introduced into tobacco by agrobacterium-mediated transformation. transgenic and control plants reacted differently when inoculated with tobacco wildfire pathogen pseudomonas syringae pv. tabaci at various cell concentrations. with ... | 1997 | 18945103 |
| identification of an isr-related metabolite produced by pseudomonas chlororaphis o6 against the wildfire pathogen pseudomonas syringae pv.tabaci in tobacco. | pseudomonas chlororaphis o6 exhibits induced systemic resistance (isr) against p. syringae pv. tabaci in tobacco. to identify one of the isr metabolites, o6 cultures were extracted with organic solvents, and the organic extracts were subjected to column chromatography followed by spectroscopy analyses. the isr bioassay-guided fractionation was carried out for isolation of the metabolite. highresolution mass spectrometric analysis of the metabolite found c(9)h(9)o(3)n with an exact mass of 179.05 ... | 2008 | 18955815 |
| overexpression of lipid transfer protein (ltp) genes enhances resistance to plant pathogens and ltp functions in long-distance systemic signaling in tobacco. | the lipid signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. to investigate the biological functions of pepper lipid transfer protein (ltp), we carried out virus-induced gene silencing (vigs) in pepper, constitutive expression of caltps and grafting experiments in the tobacco plant. suppression of endogenous caltpi and caltpii by vigs, respectively, resulted in enhanced susceptibility to xanthomonas camp ... | 2009 | 19089429 |
| differential expression of eight defensin genes of n. benthamiana following biotic stress, wounding, ethylene, and benzothiadiazole treatments. | eight nicotiana benthamiana defensin genes were identified that could be divided into two classes with class ii defensins being longer than class i defensins due to an additional acidic c-terminal domain. class i defensins were nbdef1.1, nbdef1.2, nbdef1.3, nbdef1.4, nbdef1.5, and nbdef1.6, and class ii were nbdef2.1 and nbdef2.2. relative rt-pcr showed that nbdef1.1, nbdef1.2, and nbdef1.4 had relatively similar expression levels in healthy leaves, stems, roots, flowers, and seeds. however, nbd ... | 2009 | 19214516 |
| engineered polyamine catabolism preinduces tolerance of tobacco to bacteria and oomycetes. | polyamine oxidase (pao) catalyzes the oxidative catabolism of spermidine and spermine, generating hydrogen peroxide. in wild-type tobacco (nicotiana tabacum 'xanthi') plants, infection by the compatible pathogen pseudomonas syringae pv tabaci resulted in increased pao gene and corresponding pao enzyme activities; polyamine homeostasis was maintained by induction of the arginine decarboxylase pathway and spermine was excreted into the apoplast, where it was oxidized by the enhanced apoplastic pao ... | 2009 | 19218362 |
| role of polyisoprenoids in tobacco resistance against biotic stresses. | infection with avirulent pathogens, tobacco mosaic virus (tmv) or pseudomonas syringae pv. tabaci induced accumulation of polyisoprenoid alcohols, solanesol and a family of polyprenols [from polyprenol composed of 14 isoprene units (pren-14) to -18, with pren-16 dominating] in the leaves of resistant tobacco plants nicotiana tabacum cv. samsun nn. upon tmv infection, solanesol content was increased seven- and eight-fold in the inoculated and upper leaves, respectively, while polyprenol content w ... | 2009 | 19292825 |
| extracellular atp is a regulator of pathogen defence in plants. | in healthy plants extracellular atp (eatp) regulates the balance between cell viability and death. here we show an unexpected critical regulatory role of eatp in disease resistance and defensive signalling. in tobacco, enzymatic depletion of eatp or competition with non-hydrolysable atp analogues induced pathogenesis-related (pr) gene expression and enhanced resistance to tobacco mosaic virus and pseudomonas syringae pv. tabaci. artificially increasing eatp concentrations triggered a drop in lev ... | 2009 | 19594709 |
| structural characterization of an o-linked tetrasaccharide from pseudomonas syringae pv. tabaci flagellin. | the flagellin of pseudomonas syringae pv. tabaci is a glycoprotein that contains o-linked oligosaccharides composed of rhamnosyl and 4,6-dideoxy-4-(3-hydroxybutanamido)-2-o-methylglucosyl residues. these o-linked glycans are released by hydrazinolysis and then labeled at their reducing ends with 2-aminopyridine (pa). a pa-labeled trisaccharide and a pa-labeled tetrasaccharide are isolated by normal-phase high-performance liquid chromatography. these oligosaccharides are structurally characterize ... | 2009 | 19766989 |
| genetic analysis of genes involved in synthesis of modified 4-amino-4,6-dideoxyglucose in flagellin of pseudomonas syringae pv. tabaci. | glycosylation of flagellin contributes to swimming and swarming motilities, adhesion ability, and consequently virulence in pseudomonas syringae pv. tabaci 6605. glycans attached to six serine residues are located in the central region of the flagellin polypeptide. the glycan structure at position ser 201 was recently revealed to consist of two l-rhamnoses and one modified 4-amino-4,6-dideoxyglucose (viosamine). to clarify the mechanisms for glycosylation of modified viosamine, genes encoding dt ... | 2009 | 19787374 |
| defects in flagellin glycosylation affect the virulence of pseudomonas syringae pv. tabaci 6605. | flagellar motility and its glycosylation are indispensable for the virulence of pseudomonas syringae pv. tabaci 6605. six serine residues of the flagellin protein at positions 143, 164, 176, 183, 193 and 201 are glycosylated, and the glycan structure at 201 was determined to consist of a trisaccharide of two l-rhamnosyl residues and a modified 4-amino-4,6-dideoxyglucosyl (viosamine) residue. to investigate the glycan structures attached to the other serine residues and to identify the glycans im ... | 2010 | 19815579 |
| contributions of the effector gene hopq1-1 to differences in host range between pseudomonas syringae pv. phaseolicola and p. syringae pv. tabaci. | to study the role of type iii-secreted effectors in the host adaptation of the tobacco (nicotiana sp.) pathogen pseudomonas syringae pv. tabaci, a selection of seven strains was first characterized by multilocus sequence typing (mlst) to determine their phylogenetic affinity. mlst revealed that all strains represented a tight phylogenetic group and that the most closely related strain with a completely sequenced genome was the bean (phaseolus vulgaris) pathogen p. syringae pv. phaseolicola 1448a ... | 2009 | 19849789 |
| the siderophore pyoverdine of pseudomonas syringae pv. tabaci 6605 is an intrinsic virulence factor in host tobacco infection. | to investigate the role of iron uptake mediated by the siderophore pyoverdine in the virulence of the plant pathogen pseudomonas syringae pv. tabaci 6605, three predicted pyoverdine synthesis-related genes, pvdj, pvdl, and fpva, were mutated. the pvdj, pvdl, and fpva genes encode the pyoverdine side chain peptide synthetase iii l-thr-l-ser component, the pyoverdine chromophore synthetase, and the tonb-dependent ferripyoverdine receptor, respectively. the delta pvdj and delta pvdl mutants were un ... | 2010 | 19854904 |
| s-glycoprotein-like protein regulates defense responses in nicotiana plants against ralstonia solanacearum. | rsrga4 (for ralstonia solanacearum-responsive gene a4) encodes a polypeptide similar to s-locus glycoprotein (sgp) from brassica rapa and sgp-like proteins from ipomoea trifida and medicago truncatula. therefore, we designated rsrga4 as ntsglp (for nicotiana tabacum sgp-like protein) and nbsglp (its nicotiana benthamiana ortholog). nbsglp is expressed in root, leaf, petal, gynoecium, and stamen. expression of nbsglp was strongly induced by inoculation with an avirulent strain of r. solanacearum ... | 2010 | 20118275 |
| expression of the shpx2 peroxidase gene of stylosanthes humilis in transgenic tobacco leads to enhanced resistance to phytophthora parasitica pv. nicotianae and cercospora nicotianae. | abstract previous research indicated that the constitutive expression of a pathogen-inducible peroxidase gene (shpx6a) from stylosanthes humilis in transgenic plants resulted in enhanced resistance to fungal pathogens ( kazan, k., goulter, k.c., way, h.m. and manners, j.m. (1998) expression of a pathogenesis-related peroxidase of stylosanthes humilis in transgenic tobacco and canola and its effect on disease development. plant sci. 136, 207-217). we have now investigated another pathogen-inducib ... | 2000 | 20572969 |
| pr-1 gene family of grapevine: a uniquely duplicated pr-1 gene from a vitis interspecific hybrid confers high level resistance to bacterial disease in transgenic tobacco. | a functional contribution of pathogenesis-related 1 (pr-1) proteins to host defense has been established. however, systematic investigation of the pr-1 gene family in grapevine (vitis spp.) has not been conducted previously. through mining genomic databases, we identified 21 pr-1 genes from the vitis vinifera genome. polypeptides encoded by putative pr-1 genes had a signal sequence of about 25 residues and a mature protein of 10.9-29 kda in size. pr-1 mature proteins contained a highly conserved ... | 2010 | 20967449 |
| two flagellar stators and their roles in motility and virulence in pseudomonas syringae pv. tabaci 6605. | the motor proteins around the flagellar basal body consist of two cytoplasmic membrane proteins, mota and motb, and function as a complex that acts as the stator to generate the torque that drives rotation. genome analysis of several pseudomonas syringae pathovars revealed that there are two sets of genes encoding motor proteins: motab and motcd. deduced amino acid sequences for mota/b and motc/d showed homologies to the h(+)-driven stator from escherichia coli and na(+)-driven stator from vibri ... | 2010 | 21165649 |
| nicotiana tabacum overexpressing γ-ecs exhibits biotic stress tolerance likely through npr1-dependent salicylic acid-mediated pathway. | the elaborate networks and the crosstalk of established signaling molecules like salicylic acid (sa), jasmonic acid (ja), ethylene (et), abscisic acid (aba), reactive oxygen species (ros) and glutathione (gsh) play key role in plant defense response. to obtain further insight into the mechanism through which gsh is involved in this crosstalk to mitigate biotic stress, transgenic nicotiana tabacum overexpressing lycopersicon esculentum gamma-glutamylcysteine synthetase (leecs) gene (ntgb lines) w ... | 2011 | 21234598 |
| role of type iv pili in virulence of pseudomonas syringae pv. tabaci 6605: correlation of motility, multidrug resistance and hr-inducing activity to a nonhost plant. | to investigate the role of type iv pili in the virulence of phytopathogenic bacteria, four mutant strains for pilus biogenesis-related genes were generated in pseudomonas syringae pv. tabaci 6605. pila encodes the pilin protein as a major subunit of type iv pili, and the pilo product is reported to be required for pilus assembly. the fimu and fimt genes are predicted to produce minor pilins. western blot analysis revealed that pila, pilo, and fimu mutants, but not the fimt mutant, failed to cons ... | 2011 | 21615203 |
| cytokinins mediate resistance against pseudomonas syringae in tobacco through increased antimicrobial phytoalexin synthesis independent of salicylic acid signalling. | cytokinins are phytohormones that are involved in various regulatory processes throughout plant development, but are also produced by pathogens and known to modulate plant immunity. a novel transgenic approach enabling autoregulated cytokinin synthesis in response to pathogen infection showed that cytokinins mediate enhanced resistance against the virulent hemibiotrophic pathogen pseudomonas syringae pv. tabaci. this was confirmed by two additional independent transgenic approaches to increase e ... | 2011 | 21813654 |
| degeneration of hrpz gene in pseudomonas syringae pv. tabaci to evade tobacco defence: an arms race between tobacco and its bacterial pathogen. | the hrpz harpin of pseudomonas syringae is known to induce a hypersensitive response (hr) in some plants. in p. syringae pv. tabaci (pta), the harpin gene hrpz has been spontaneously disrupted by an internal deletion in its open reading frame and a frame shift. the loss of the ability of the recombinant harpin polypeptide of pta to induce hr despite the high sensitivity of tobacco plants to harpin led us to investigate the meaning of the disrupted hrpz gene in the virulence of pta 6605. the hrpz ... | 2011 | 21726372 |
| the role of a putative peroxisomal-targeted epoxide hydrolase of nicotiana benthamiana in interactions with colletotrichum destructivum, c. orbiculare or pseudomonas syringae pv. tabaci. | motif analysis among 30 eh1 and eh2 epoxide hydrolases from solanaceaeous plants showed differences primarily in the lid region around the catalytic site. based on in silico models of 3d structures, eh1 proteins lack a catalytic triad because of the orientation of one of the conserved lid tyrosines, while the orientation of that tyrosine in eh2 proteins fomed a catalytic triad inside a hydrophobic tunnel. two similar eh2 protein genes from nicotiana benthamiana, nbeh2.1 and nbeh2.2, have a predi ... | 2011 | 21683883 |
| gaca directly regulates expression of several virulence genes in pseudomonas syringae pv. tabaci 11528. | a two-component system comprising gacs and gaca affects a large number of traits in many gram-negative bacteria. however, the signals to which gacs responds, the regulation mechanism for gaca expression, and the genes gaca controls are not yet clear. in this study, several phenotypic tests and tobacco-leaf pathogenicity assays were conducted using a gaca deletion mutant strain (bl473) of pseudomonas syringae pv. tabaci 11528. to determine the regulation mechanism for gaca gene expression and to ... | 2011 | 22166197 |