| the bacterial type iii secretion system-associated pilin hrpa has an unusually long mrna half-life. | secondary structures affect mrna stability and may play a role in protein secretion. we have studied the mrna of hrpa, which codes for the major structural unit of the type iii secretion system-associated pilus of pseudomonas syringae pv. tomato, erwinia carotovora and pseudomonas syringae pv. phaseolicola. we show that hrpa mrna has an unusually long half-life, approximately 33-47 min. we mapped regions in the transcript that affected hrpa mrna accumulation. apparently, sequences at both 5' and ... | 2004 | 15280045 |
| diverse evolutionary mechanisms shape the type iii effector virulence factor repertoire in the plant pathogen pseudomonas syringae. | many gram-negative pathogenic bacteria directly translocate effector proteins into eukaryotic host cells via type iii delivery systems. type iii effector proteins are determinants of virulence on susceptible plant hosts; they are also the proteins that trigger specific disease resistance in resistant plant hosts. evolution of type iii effectors is dominated by competing forces: the likely requirement for conservation of virulence function, the avoidance of host defenses, and possible adaptation ... | 2004 | 15280247 |
| antibacterial activity of the chinese traditional medicine, zi hua di ding. | the antibacterial activity of extracts from species of plants used in the chinese medicine, zi hua di ding (viola yedoensis, v. prionantha, corydalis bungeana and gueldenstaedtia verna), was tested against bacillus subtilis and pseudomonas syringae using a bioautographic assay. the petroleum ether and ethyl acetate extracts of all four species of plants showed activity against both species of bacteria, whereas the methanol and aqueous methanol extracts were inactive. three fractions from the pet ... | 2004 | 15287078 |
| topological and deletion analysis of cors, a pseudomonas syringae sensor kinase. | a modified two-component regulatory system consisting of two response regulators, corr and corp, and the histidine protein kinase cors, regulates the thermoresponsive production of the phytotoxin coronatine (cor) in pseudomonas syringae pg4180. cor is produced at the virulence-promoting temperature of 18 degrees c, but not at 28 degrees c, the optimal growth temperature of pg4180. assuming that the highly hydrophobic n-terminus of cors might be involved in temperature-signal perception, the memb ... | 2004 | 15289568 |
| algr functions in algc expression and virulence in pseudomonas syringae pv. syringae. | pseudomonas syringae pv. syringae strain ff5 is a phytopathogen associated with a rapid dieback on ornamental pear trees. p. syringae and the human pathogen pseudomonas aeruginosa produce the exopolysaccharide alginate, a copolymer of mannuronic and guluronic acid. in p. aeruginosa, the response regulator algr (algr1) is required for transcription of algc and algd, which encode key enzymes in the alginate biosynthetic pathway. in p. syringae ff5, however, algr is not required for the activation ... | 2004 | 15289569 |
| inappropriate annotation of a key defence marker in arabidopsis: will the real pr-1 please stand up? | pr-1 has been extensively used as a marker for salicylic acid (sa)-mediated defence and systemic and local acquired resistance. the arabidopsis genome project annotates at2g19990 as pr-1. this gene is also identified as pr-1 in two "full genome" arabidopsis microarrays, and tair cites approximately 60 articles to describe its patterns of expression. however, most of these citations are incorrect; the probes used were not at2g19990, but a homologous gene at2g14610, which is annotated as "pr-1-lik ... | 2004 | 15293050 |
| polysaccharides of pseudomonas pathovar strains that infect pea, tomato, and soya bean. | in order to understand the mode of action of taxonomically related pseudomonas syringae pathovar strains that infect pea, tomato, and soya bean, we examined their extracellular polysaccharides (eps). maximum production of polysaccharide in shake culture of these pathogens was observed between 24 and 60 h. p. syringae pv. pisi 519, the bacterial blight pathogen of pea, produced a higher amount of polysaccharide (34.87 microg/ml) at 60 h compared with 32.67 microg/ml produced by p. syringae pv. gl ... | 2004 | 15297928 |
| characterization of a root-specific arabidopsis terpene synthase responsible for the formation of the volatile monoterpene 1,8-cineole. | arabidopsis is emerging as a model system to study the biochemistry, biological functions, and evolution of plant terpene secondary metabolism. it was previously shown that the arabidopsis genome contains over 30 genes potentially encoding terpene synthases (tpss). here we report the characterization of a monoterpene synthase encoded by two identical, closely linked genes, at3g25820 and at3g25830. transcripts of these genes were detected almost exclusively in roots. an at3g25820/at3g25830 cdna w ... | 2004 | 15299125 |
| antisense downregulation of polyphenol oxidase results in enhanced disease susceptibility. | polyphenol oxidases (ppos; ec 1.14.18.1 or ec 1.10.3.2) catalyze the oxidation of phenolics to quinones, highly reactive intermediates whose secondary reactions are responsible for much of the oxidative browning that accompanies plant senescence, wounding, and responses to pathogens. to assess the impact of ppo expression on resistance to pseudomonas syringae pv. tomato we introduced a chimeric antisense potato ppo cdna into tomato (lycopersicon esculentum l.). oxidation of caffeic acid, the dom ... | 2004 | 15300439 |
| modeling the function of bacterial virulence factors in saccharomyces cerevisiae. | | 2004 | 15302815 |
| the hotdog fold: wrapping up a superfamily of thioesterases and dehydratases. | the hotdog fold was initially identified in the structure of escherichia coli faba and subsequently in 4-hydroxybenzoyl-coa thioesterase from pseudomonas sp. strain cbs. since that time structural determinations have shown a number of other apparently unrelated proteins also share the hotdog fold. | 2004 | 15307895 |
| pathogen- and nacl-induced expression of the scam-4 promoter is mediated in part by a gt-1 box that interacts with a gt-1-like transcription factor. | the ca(2+)-binding protein calmodulin mediates cellular ca(2+) signals in response to a wide array of stimuli in higher eukaryotes. plants express numerous cam isoforms. transcription of one soybean (glycine max) cam isoform, scam-4, is dramatically induced within 30 min of pathogen or nacl stresses. to characterize the cis-acting element(s) of this gene, we isolated an approximately 2-kb promoter sequence of the gene. deletion analysis of the promoter revealed that a 130-bp region located betwe ... | 2004 | 15310827 |
| jasmonic acid is a key regulator of spider mite-induced volatile terpenoid and methyl salicylate emission in tomato. | the tomato (lycopersicon esculentum) mutant def-1, which is deficient in induced jasmonic acid (ja) accumulation upon wounding or herbivory, was used to study the role of ja in the direct and indirect defense responses to phytophagous mites (tetranychus urticae). in contrast to earlier reports, spider mites laid as many eggs and caused as much damage on def-1 as on wild-type plants, even though def-1 lacked induction of proteinase inhibitor activity. however, the hatching-rate of eggs on def-1 w ... | 2004 | 15310835 |
| the use of vapor phase extraction in metabolic profiling of phytohormones and other metabolites. | through complex networks of signaling interactions, phytohormones regulate growth, development, reproduction and responses to biotic and abiotic stress. comprehensive metabolomic approaches, seeking to quantify changes in vast numbers of plant metabolites, may ultimately clarify these complex signaling interactions and consequently explain pleiotropic effects on plant metabolism. synergistic and antagonistic phytohormone signaling interactions, referred to as crosstalk, are often considered at t ... | 2004 | 15315639 |
| functional characterization of an aminotransferase required for pyoverdine siderophore biosynthesis in pseudomonas aeruginosa pao1. | the fluorescent dihydroxyquinoline chromophore of the pyoverdine siderophore in pseudomonas is a condensation product of d-tyrosine and l-2,4-diaminobutyrate. both pvdh and asd (encoding aspartate beta-semialdehyde dehydrogenase) knockout mutants of pseudomonas aeruginosa pao1 were unable to synthesize pyoverdine under iron-limiting conditions in the absence of l-2,4-diaminobutyrate in the culture media. the pvdh gene was subcloned, and the gene product was hyperexpressed and purified from p. ae ... | 2004 | 15317763 |
| cloning and expression of afpa, a gene encoding an antifreeze protein from the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2. | the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2 secretes an antifreeze protein (afp) that promotes survival at subzero temperatures. the afp is unusual in that it also exhibits a low level of ice nucleation activity. a dna fragment with an open reading frame encoding 473 amino acids was cloned by pcr and inverse pcr using primers designed from partial amino acid sequences of the isolated afp. the predicted gene product, afpa, had a molecular mass of 47.3 kda, a pi of 3 ... | 2004 | 15317770 |
| a putative polyketide synthase/peptide synthetase from magnaporthe grisea signals pathogen attack to resistant rice. | isolates of the rice blast fungus magnaporthe grisea that carry the gene encoding avirulence conferring enzyme1 (ace1) are specifically recognized by rice (oryza sativa) cultivars carrying the resistance gene pi33. this recognition enables resistant plants to activate a defense response. ace1 was isolated by map-based cloning and encodes a putative hybrid between a polyketide synthase and a nonribosomal peptide synthetase, enzymes involved in microbial secondary metabolism. ace1 is expressed exc ... | 2004 | 15319478 |
| combined effects of blood and temperature shift on borrelia burgdorferi gene expression as determined by whole genome dna array. | borrelia burgdorferi undergoes differential gene expression during transmission from its tick vector to a vertebrate host. the addition of blood to a spirochete culture at 35 degrees c for 48 h had a dramatic effect on gene expression of this organism. utilizing b. burgdorferi whole genome dna arrays, we compared the transcriptomes of the spirochetes following a 2-day temperature shift with blood and without blood. using combined data from three independent rna isolations we demonstrated that th ... | 2004 | 15322040 |
| regulation of plant arginase by wounding, jasmonate, and the phytotoxin coronatine. | in mammalian cells, induced expression of arginase in response to wound trauma and pathogen infection plays an important role in regulating the metabolism of l-arginine to either polyamines or nitric oxide (no). in higher plants, which also utilize arginine for the production of polyamines and no, the potential role of arginase as a control point for arginine homeostasis has not been investigated. here, we report the characterization of two genes (learg1 and learg2) from lycopersicon esculentum ... | 2004 | 15322128 |
| terbinafine resistance mediated by salicylate 1-monooxygenase in aspergillus nidulans. | resistance to antifungal agents is a recurring and growing problem among patients with systemic fungal infections. uv-induced aspergillus nidulans mutants resistant to terbinafine have been identified, and we report here the characterization of one such gene. a sib-selected, 6.6-kb genomic dna fragment encodes a salicylate 1-monooxygenase (sala), and a fatty acid synthase subunit (fasc) confers terbinafine resistance upon transformation of a sensitive strain. subfragments carrying sala but not f ... | 2004 | 15328121 |
| in search of rnase p rna from microbial genomes. | a simple procedure has been developed to quickly retrieve and validate the dna sequence encoding the rna subunit of ribonuclease p (rnase p rna) from microbial genomes. rnase p rna sequences were identified from 94% of bacterial and archaeal complete genomes where previously no rnase p rna was annotated. a sequence was found in camelpox virus, highly conserved in all orthopoxviruses (including smallpox virus), which could fold into a putative rnase p rna in terms of conserved primary features an ... | 2004 | 15337843 |
| crystal structures of the type iii effector protein avrpphf and its chaperone reveal residues required for plant pathogenesis. | the avrpphf locus from pseudomonas syringae pv. phaseolicola, the causative agent of bean halo-blight disease, encodes proteins which either enhance virulence on susceptible hosts or elicit defense responses on hosts carrying the r1 resistance gene. here we present the crystal structures of the two proteins from the avrpphf operon. the structure of avrpphf orf1 is strikingly reminiscent of type iii chaperones from bacterial pathogens of animals, indicating structural conservation of these specia ... | 2004 | 15341731 |
| new protein-protein interactions identified for the regulatory and structural components and substrates of the type iii secretion system of the phytopathogen xanthomonas axonopodis pathovar citri. | we have initiated a project to identify protein-protein interactions involved in the pathogenicity of the bacterial plant pathogen xanthomonas axonopodis pv. citri. using a yeast two-hybrid system based on gal4 dna-binding and activation domains, we have focused on identifying interactions involving subunits, regulators, and substrates of the type iii secretion system coded by the hrp (for hypersensitive response and pathogenicity), hrc (for hrp conserved), and hpa (for hrp associated) genes. we ... | 2004 | 15342589 |
| mutational analysis of xanthomonas harpin hpag identifies a key functional region that elicits the hypersensitive response in nonhost plants. | hpag is a type iii-secreted elicitor protein of xanthomonas axonopodis pv. glycines. we have determined the critical amino acid residues important for hypersensitive response (hr) elicitation by random and site-directed mutagenesis of hpag and its homolog xopa. a plasmid clone carrying hpag was mutagenized by site-directed mutagenesis, hydroxylamine mutagenesis, and error-prone pcr. a total of 52 mutants were obtained, including 51 single missense mutants and 1 double missense mutant. the hr eli ... | 2004 | 15342594 |
| [aberrant development of pollen in transgenic tobacco expressing bacterial iaam gene driven by pollen- and tapetum-specific promoters]. | microsporogenesis offers an ideal model for studying gene expression, cell division and cell to cell communication during development. the role of auxin in pollen development was investigated in transgenic tobacco plants expressing the coding region of the iaam gene from pseudomonas syringae, under control of the promoters lat-52 (pollen-specific) or ta-29 (tapetum-specific). iaa level in anther of transgenic plants increased significantly, and transgenic plants displayed morphological aberratio ... | 2002 | 15344309 |
| comparison of atpase-encoding type iii secretion system hrcn genes in biocontrol fluorescent pseudomonads and in phytopathogenic proteobacteria. | type iii protein secretion systems play a key role in the virulence of many pathogenic proteobacteria, but they also occur in nonpathogenic, plant-associated bacteria. certain type iii protein secretion genes (e.g., hrcc) have been found in pseudomonas sp. strain sbw25 (and other biocontrol pseudomonads), but other type iii protein secretion genes, such as the atpase-encoding gene hrcn, have not been found. using both colony hybridization and a pcr approach, we show here that hrcn is nevertheles ... | 2004 | 15345390 |
| regulation of the n-acyl homoserine lactone-dependent quorum-sensing system in rhizosphere pseudomonas putida wcs358 and cross-talk with the stationary-phase rpos sigma factor and the global regulator gaca. | quorum sensing is a cell population-density dependent regulatory system which in gram-negative bacteria often involves the production and detection of n-acyl homoserine lactones (ahls). some pseudomonas putida strains have been reported to produce ahls, and one quorum-sensing locus has been identified. however, it appears that the majority of strains do not produce ahls. in this study we report the identification and regulation of the ahl-dependent system of rhizosphere p. putida wcs358. this sy ... | 2004 | 15345437 |
| 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 |
| modulation of the biological activity of a tobacco ltp1 by lipid complexation. | plant lipid transfer proteins (ltps) are small, cysteine-rich proteins secreted into the extracellular space. they belong to the pathogenesis-related proteins (pr-14) family and are believed to be involved in several physiological processes including plant disease resistance, although their precise biological function is still unknown. here, we show that a recombinant tobacco ltp1 is able to load fatty acids and jasmonic acid. this ltp1 binds to specific plasma membrane sites, previously charact ... | 2004 | 15356262 |
| arabidopsis rin4 negatively regulates disease resistance mediated by rps2 and rpm1 downstream or independent of the ndr1 signal modulator and is not required for the virulence functions of bacterial type iii effectors avrrpt2 or avrrpm1. | bacterial pathogens deliver type iii effector proteins into the plant cell during infection. on susceptible (r) hosts, type iii effectors can contribute to virulence. some trigger the action of specific disease resistance (r) gene products. the activation of r proteins can occur indirectly via modification of a host target. thus, at least some type iii effectors are recognized at site(s) where they may act as virulence factors. these data indicate that a type iii effector's host target might be ... | 2004 | 15361584 |
| arabidopsis nonsymbiotic hemoglobin ahb1 modulates nitric oxide bioactivity. | nitric oxide (no) is a widespread signaling molecule, and numerous targets of its action exist in plants. whereas the activity of no in erythrocytes, microorganisms, and invertebrates has been shown to be regulated by several hemoglobins, the function of plant hemoglobins in no detoxification has not yet been elucidated. here, we show that arabidopsis thaliana nonsymbiotic hemoglobin ahb1 scavenges no through production of s-nitrosohemoglobin and reduces no emission under hypoxic stress, indicat ... | 2004 | 15367716 |
| a patch of surface-exposed residues mediates negative regulation of immune signaling by tomato pto kinase. | tomato (lycopersicon esculentum) pto kinase specifically recognizes the pseudomonas effector proteins avrpto and avrptob, leading to induction of defense responses and hypersensitive cell death. structural modeling of pto combined with site-directed mutagenesis identified a patch of surface-exposed residues required for native regulation of signaling. mutations in this area resulted in constitutive gain-of-function (cgf) forms of pto that activated avrpto-independent cell death via the cognate s ... | 2004 | 15367718 |
| identification of mapks and their possible mapk kinase activators involved in the pto-mediated defense response of tomato. | the pto kinase mediates resistance to bacterial speck disease in tomato by activating host defenses upon recognition of pseudomonas syringae pv. tomato strains expressing the avrpto or avrptob proteins. previous gene-silencing experiments have indicated that mitogen activated protein kinase (mapk) cascades play a key role downstream of the pto kinase to activate host defense responses. here we use biochemical methods to demonstrate that two tomato mapks, lempk2 and lempk3, are activated in leave ... | 2004 | 15371431 |
| complete genomic sequence of bacteriophage b3, a mu-like phage of pseudomonas aeruginosa. | bacteriophage b3 is a transposable phage of pseudomonas aeruginosa. in this report, we present the complete dna sequence and annotation of the b3 genome. dna sequence analysis revealed that the b3 genome is 38,439 bp long with a g+c content of 63.3%. the genome contains 59 proposed open reading frames (orfs) organized into at least three operons. of these orfs, the predicted proteins from 41 orfs (68%) display significant similarity to other phage or bacterial proteins. many of the predicted b3 ... | 2004 | 15375138 |
| an energy taxis transducer promotes root colonization by azospirillum brasilense. | motility responses triggered by changes in the electron transport system are collectively known as energy taxis. in azospirillum brasilense, energy taxis was shown to be the principal form of locomotor control. in the present study, we have identified a novel chemoreceptor-like protein, named tlp1, which serves as an energy taxis transducer. the tlp1 protein is predicted to have an n-terminal periplasmic region and a cytoplasmic c-terminal signaling module homologous to those of other chemorecep ... | 2004 | 15375141 |
| genomic plasticity of the causative agent of melioidosis, burkholderia pseudomallei. | burkholderia pseudomallei is a recognized biothreat agent and the causative agent of melioidosis. this gram-negative bacterium exists as a soil saprophyte in melioidosis-endemic areas of the world and accounts for 20% of community-acquired septicaemias in northeastern thailand where half of those affected die. here we report the complete genome of b. pseudomallei, which is composed of two chromosomes of 4.07 megabase pairs and 3.17 megabase pairs, showing significant functional partitioning of g ... | 2004 | 15377794 |
| consequences of binding an s-adenosylmethionine analogue on the structure and dynamics of the thiopurine methyltransferase protein backbone. | in humans, the enzyme thiopurine methyltransferase (tpmt) metabolizes 6-thiopurine (6-tp) medications, commonly used for immune suppression and for the treatment of hematopoietic malignancies. genetic polymorphisms in the tpmt protein sequence accelerate intracellular degradation of the enzyme through an ubiquitylation and proteasomal-dependent pathway. research has led to the hypothesis that these polymorphisms destabilize the native structure of tpmt, resulting in the formation of misfolded or ... | 2004 | 15379558 |
| a key role for ald1 in activation of local and systemic defenses in arabidopsis. | the arabidopsis thaliana agd2-like defense response protein1 (ald1) mutant was previously found to be hypersusceptible to the virulent bacterial pathogen pseudomonas syringae and had reduced accumulation of the defense signal salicylic acid (sa). ald1 was shown to possess aminotransferase activity in vitro, suggesting it generates an amino acid-derived defense signal. we now find ald1 to be a key defense component that acts in multiple contexts and partially requires the phytoalexin deficient4 ( ... | 2004 | 15447647 |
| expression of rps4 in tobacco induces an avrrps4-independent hr that requires eds1, sgt1 and hsp90. | the arabidopsis rps4 gene belongs to the toll/interleukin-1 receptor/nucleotide-binding site/leucine-rich repeat (tir-nb-lrr) class of plant resistance (r) genes. it confers resistance to pseudomonas syringae carrying the avirulence gene avrrps4. transient expression of genomic rps4 driven by the 35s promoter in tobacco leaves induces an avrrps4-independent hypersensitive response (hr). the same phenotype is seen after expression of a full-length rps4 cdna. this indicates that alternative splici ... | 2004 | 15447648 |
| overexpression of the plasma membrane-localized ndr1 protein results in enhanced bacterial disease resistance in arabidopsis thaliana. | previous studies have established that mutations in the ndr1 gene in arabidopsis thaliana suppress the resistance response of three resistance proteins, rps2, rpm1, and rps5, to pseudomonas syringae pv. tomato (pst) strain dc3000 containing the cognate effector genes, avrrpt2, avrrpm1, and avrpphb, respectively. ndr1 is a plasma membrane (pm)-localized protein, and undergoes several post-translational modifications including carboxy-terminal processing and n-linked glycosylation. expression of n ... | 2004 | 15447649 |
| intragenomic heterogeneity of the 16s rrna-23s rrna internal transcribed spacer among pseudomonas syringae and pseudomonas fluorescens strains. | the 16s-23s rrna internal transcribed spacer regions (its1) from 14 strains of pseudomonas syringae and p. fluorescens were sequenced. its1 exhibited significant sequence variability among different operons within a single genome. from 1 to 4 types of its1 were found in individual genomes of the p. syringae and p. fluorescens strains. a total of eight its1 types were identified among strains studied. the its1 nucleotide sequences consisted of conserved blocks including, among others, a stem-form ... | 2004 | 15451096 |
| replicon-specific regulation of small heat shock genes in agrobacterium tumefaciens. | four genes coding for small heat shock proteins (shsps) were identified in the genome sequence of agrobacterium tumefaciens, one on the circular chromosome (hspc), one on the linear chromosome (hspl), and two on the pat plasmid (hspat1 and hspat2). induction of shsps at elevated temperatures was revealed by immunoblot analyses. primer extension experiments and translational lacz fusions demonstrated that expression of the pat-derived genes and hspl is controlled by temperature in a regulon-speci ... | 2004 | 15466035 |
| antimicrobial activity of some pentacyclic triterpenes and their synthesized 3-o-lipophilic chains. | the major metabolites of diopsyros melanoxylon viz. amyrins and ursolic acid and their lipophilic 3-o-fatty acid ester chains (c12-c18), which are synthesized now under mild esterification conditions in excellent yields (80-95%), were evaluated for their antimicrobial activity against a series of gram positive and gram negative bacteria. significantly these compounds were found to exhibit potent activity against gram negative bacteria pseudomonas syringae (atcc #13457) and fairly good activity a ... | 2004 | 15467198 |
| disabling surveillance: bacterial type iii secretion system effectors that suppress innate immunity. | many gram-negative bacterial pathogens of plants and animals are dependent on a type iii protein secretion system (ttss). ttsss translocate effector proteins into host cells and are capable of modifying signal transduction pathways. the innate immune system of eukaryotes detects the presence of pathogens using specific pathogen recognition receptors (prrs). plant prrs include the fls2 receptor kinase and resistance proteins. animal prrs include toll-like receptors and nucleotide-binding oligomer ... | 2004 | 15469432 |
| two arabidopsis srfr (suppressor of rps4-rld) mutants exhibit avrrps4-specific disease resistance independent of rps4. | rps4 specifies the arabidopsis disease resistance response to pseudomonas syringae pv. tomato expressing avrrps4 and was cloned based on the identification of rld as a naturally occurring susceptible accession. to dissect the molecular and genetic basis of disease resistance, we used a genetic approach to identify suppressor mutations that reactivate the avrrps4-triggered defense response in rld. in this report, we describe two non-allelic srfr (suppressor of rps4-rld) mutants, srfr1 and srfr3, ... | 2004 | 15469494 |
| hoppton is a pseudomonas syringae hrp (type iii secretion system) cysteine protease effector that suppresses pathogen-induced necrosis associated with both compatible and incompatible plant interactions. | pseudomonas syringae pv. tomato dc3000 causes bacterial speck disease in tomato, and it elicits the hypersensitive response (hr) in non-host plants such as nicotiana tabacum and nicotiana benthamiana. the compatible and incompatible interactions of dc3000 with tomato and nicotiana spp., respectively, result in plant cell death, but the hr cell death occurs more rapidly and is associated with effective plant defense. both interactions require the hrp (hr and pathogenicity) type iii secretion syst ... | 2004 | 15469508 |
| molecular characterization of a thij-like gene in chinese cabbage. | a cdna clone for a salicylic acid-induced gene in chinese cabbage (brassica rapa subsp. pekinensis) was isolated and characterized. the cabbage gene encoding a protein of 392 amino acids contained a tandem array of two thij-like sequences. thij is a thiamin biosynthesis enzyme that catalyzes the phosphorylation of hydroxymethylpyrimidine (hmp) to hmp monophosphate. although the cabbage gene shows a similarity to bacterial thij genes, it also shares a similarity with the human dj-1, a multifuncti ... | 2004 | 15469717 |
| 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 |
| 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 |
| the completely sequenced plasmid pest4011 contains a novel incp1 backbone and a catabolic transposon harboring tfd genes for 2,4-dichlorophenoxyacetic acid degradation. | the herbicide 2,4-dichlorophenoxyacetic acid (2,4-d)-degrading bacterium achromobacter xylosoxidans subsp. denitrificans strain est4002 contains plasmid pest4011. this plasmid ensures its host a stable 2,4-d(+) phenotype. we determined the complete 76,958-bp nucleotide sequence of pest4011. this plasmid is a deletion and duplication derivative of pd2m4, the 95-kb highly unstable laboratory ancestor of pest4011, and was self-generated during different laboratory manipulations performed to increas ... | 2004 | 15489427 |
| construction of an enterococcus faecalis tn917-mediated-gene-disruption library offers insight into tn917 insertion patterns. | sequencing the insertion sites of 8,865 tn917 insertions in enterococcus faecalis strain og1rf identified a hot spot in the replication terminus region corresponding to 6% of the genome where 65% of the transposons had inserted. in e. faecalis, tn917 preferentially inserted at a 29-bp consensus sequence centered on tataa, a 5-bp sequence that is duplicated during insertion. the regional insertion site preference at the chromosome terminus was not observed in another low-g+c gram-positive bacteri ... | 2004 | 15489440 |
| algx is a periplasmic protein required for alginate biosynthesis in pseudomonas aeruginosa. | alginate, an exopolysaccharide produced by pseudomonas aeruginosa, provides the bacterium with a selective advantage that makes it difficult to eradicate from the lungs of cystic fibrosis (cf) patients. previous studies identified a gene, algx, within the alginate biosynthetic gene cluster on the p. aeruginosa chromosome. by probing cell fractions with anti-algx antibodies in a western blot, algx was localized within the periplasm. consistent with these results is the presence of a 26-amino-acid ... | 2004 | 15489449 |
| use of in vivo expression technology to identify genes important in growth and survival of pseudomonas fluorescens pf0-1 in soil: discovery of expressed sequences with novel genetic organization. | studies were undertaken to determine the genetic needs for the survival of pseudomonas fluorescens pf0-1, a gram-negative soil bacterium potentially important for biocontrol and bioremediation, in soil. in vivo expression technology (ivet) identified 22 genes with elevated expression in soil relative to laboratory media. soil-induced sequences included genes with probable functions of nutrient acquisition and use, and of gene regulation. ten sequences, lacking similarity to known genes, overlapp ... | 2004 | 15489453 |
| impact of temperature on in planta expression of genes involved in synthesis of the pseudomonas syringae phytotoxin coronatine. | coronatine (cor) is a chlorosis-inducing phytotoxin produced by the plant-pathogenic bacterium pseudomonas syringae. confocal laser scanning microscopy was used to investigate in vitro and in planta expression of cor genes by two model organisms, p. syringae pv. glycinea pg4180, a pathogen of soybean, and p syringae pv. tomato dc3000, a pathogen of tomato and crucifers. previously, it was shown in vitro that the cma operon involved in cor synthesis in pg4180 is expressed in a temperature-depende ... | 2004 | 15497402 |
| overexpression of nterf5, a new member of the tobacco ethylene response transcription factor family enhances resistance to tobacco mosaic virus. | a new member of the tobacco (nicotiana tabacum) ap2/erf (ethylene response factor) transcription factor family, designated nterf5, has been isolated by yeast one-hybrid screening. in vitro, recombinant nterf5 protein weakly binds gcc box cis-elements, which mediate pathogen-regulated transcription of several pr (pathogenesis related) genes. nterf5 transcription is transiently activated by wounding, by infection with the bacterial pathogen pseudomonas syringae, as well as by inoculation with toba ... | 2004 | 15497409 |
| 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 |
| the bos loci of arabidopsis are required for resistance to botrytis cinerea infection. | three botrytis-susceptible mutants bos2, bos3, and bos4 which define independent and novel genetic loci required for arabidopsis resistance to botrytis cinerea were isolated. the bos2 mutant is susceptible to b. cinerea but retains wild-type levels of resistance to other pathogens tested, indicative of a defect in a response pathway more specific to b. cinerea. the bos3 and bos4 mutants also show increased susceptibility to alternaria brassicicola, another necrotrophic pathogen, suggesting a bro ... | 2004 | 15500471 |
| unique features revealed by the genome sequence of acinetobacter sp. adp1, a versatile and naturally transformation competent bacterium. | acinetobacter sp. strain adp1 is a nutritionally versatile soil bacterium closely related to representatives of the well-characterized pseudomonas aeruginosa and pseudomonas putida. unlike these bacteria, the acinetobacter adp1 is highly competent for natural transformation which affords extraordinary convenience for genetic manipulation. the circular chromosome of the acinetobacter adp1, presented here, encodes 3325 predicted coding sequences, of which 60% have been classified based on sequence ... | 2004 | 15514110 |
| suppression of pathogen-inducible no synthase (inos) activity in tomato increases susceptibility to pseudomonas syringae. | | 2004 | 15516371 |
| downstream divergence of the ethylene signaling pathway for harpin-stimulated arabidopsis growth and insect defense. | ethylene (et) signal transduction may regulate plant growth and defense, depending on which components are recruited into the pathway in response to different stimuli. we report here that the et pathway controls both insect resistance (ir) and plant growth enhancement (pge) in arabidopsis (arabidopsis thaliana) plants responding to harpin, a protein produced by a plant pathogenic bacterium. pge may result from spraying plant tops with harpin or by soaking seeds in harpin solution; the latter esp ... | 2004 | 15516507 |
| analysis of the cytoplasmic domains of salmonella flha and interactions with components of the flagellar export machinery. | most flagellar proteins are exported via a type iii export apparatus which, in part, consists of the membrane proteins flha, flhb, flio, flip, fliq, and flir and is housed within the membrane-supramembrane ring formed by flif subunits. salmonella flha is a 692-residue integral membrane protein with eight predicted transmembrane spans. its function is not understood, but it is necessary for flagellar export. we have created mutants in which potentially important sequences were deleted. flha lacki ... | 2004 | 15516571 |
| long-term effect of mutagenic dna repair on accumulation of mutations in pseudomonas syringae b86-17. | forty replicate lineages of pseudomonas syringae b86-17 cells expressing the rulab mutagenic dna repair (mdr) determinant or the rulb::km mdr-deficient mutant gws242 were passaged through single-cell bottlenecks (60 cycles), with a uv radiation (uvr) exposure given to half of the lineages at the beginning of each cycle. after every 10th bottleneck cycle, single-colony isolates from all 80 lineages were subjected to 39 phenotypic screens, with newly arising mutations detected in 60 and 0% of uvr- ... | 2004 | 15516596 |
| inactivation of an abc transporter gene, mcyh, results in loss of microcystin production in the cyanobacterium microcystis aeruginosa pcc 7806. | the cyanobacterium microcystis aeruginosa is widely known for its production of the potent hepatotoxin microcystin. microcystin is synthesized nonribosomally by the thiotemplate function of a large, modular enzyme complex encoded within the 55-kb microcystin synthetase (mcy) gene cluster. also encoded within the mcy gene cluster is a putative atp binding cassette (abc) transporter, mcyh. this study details the bioinformatic and mutational analyses of mcyh and offers functional predictions for th ... | 2004 | 15528494 |
| survival of shewanella oneidensis mr-1 after uv radiation exposure. | we systematically investigated the physiological response as well as dna damage repair and damage tolerance in shewanella oneidensis mr-1 following uvc, uvb, uva, and solar light exposure. mr-1 showed the highest uvc sensitivity among shewanella strains examined, with d37 and d10 values of 5.6 and 16.5% of escherichia coli k-12 values. stationary cells did not show an increased uva resistance compared to exponential-phase cells; instead, they were more sensitive at high uva dose. uva-irradiated ... | 2004 | 15528503 |
| vpegamma exhibits a caspase-like activity that contributes to defense against pathogens. | caspases are a family of aspartate-specific cysteine proteases that play an essential role in initiating and executing programmed cell death (pcd) in metazoans. caspase-like activities have been shown to be required for the initiation of pcd in plants, but the genes encoding those activities have not been identified. vpegamma, a cysteine protease, is induced during senescence, a form of pcd in plants, and is localized in precursor protease vesicles and vacuoles, compartments associated with pcd ... | 2004 | 15530390 |
| the pyoverdins of pseudomonas syringae and pseudomonas cichorii. | the structure elucidation of the cyclic (lactonic) forms of the pyoverdins with a succinamide side chain originally produced by the closely related species pseudomonas syringae and p. cichorii is reported. mass spectrometry and nuclear magnetic resonance analyses as well as the determination of the configuration of the amino acids after degradation indicate that these two pyoverdins differ only by the replacement of the first in-chain serine by glycine. the pyoverdins of p. syringae and p. cicho ... | 2004 | 15540590 |
| a genetic screen to isolate type iii effectors translocated into pepper cells during xanthomonas infection. | the bacterial pathogen xanthomonas campestris pv. vesicatoria (xcv) uses a type iii secretion system (ttss) to translocate effector proteins into host plant cells. the ttss is required for xcv colonization, yet the identity of many proteins translocated through this apparatus is not known. we used a genetic screen to functionally identify xcv ttss effectors. a transposon 5 (tn5)-based transposon construct including the coding sequence for the xcv avrbs2 effector devoid of its ttss signal was ran ... | 2004 | 15545602 |
| the pseudomonas syringae type iii effector avrrpt2 promotes virulence independently of rin4, a predicted virulence target in arabidopsis thaliana. | avrrpt2, an effector protein from pseudomonas syringae pv. tomato (pst), behaves as an avirulence factor that activates resistance in arabidopsis thaliana lines expressing the resistance gene rps2. avrrpt2 can also enhance pathogen fitness by promoting the ability of the bacteria to grow and to cause disease on susceptible lines of a. thaliana that lack functional rps2. the activation of rps2 is coupled to the avrrpt2-induced disappearance of the a. thaliana rin4 protein. however, the significan ... | 2004 | 15546361 |
| ralstonia solanacearum iron scavenging by the siderophore staphyloferrin b is controlled by phca, the global virulence regulator. | phca is a transcriptional regulator that activates expression of multiple virulence genes in the plant pathogen ralstonia solanacearum. relative to their wild-type parents, phca mutants overproduced iron-scavenging activity detected with chrome azurol s siderophore detection medium. transposon mutagenesis of strain aw1-pc (phca1) generated strain gb6, which was siderophore negative but retained weak iron-scavenging activity. the ssd gene inactivated in gb6 encodes a protein similar to group iv a ... | 2004 | 15547261 |
| bacteriophage and phenotypic variation in pseudomonas aeruginosa biofilm development. | a current question in biofilm research is whether biofilm-specific genetic processes can lead to differentiation in physiology and function among biofilm cells. in pseudomonas aeruginosa, phenotypic variants which exhibit a small-colony phenotype on agar media and a markedly accelerated pattern of biofilm development compared to that of the parental strain are often isolated from biofilms. we grew p. aeruginosa biofilms in glass flow cell reactors and observed that the emergence of small-colony ... | 2004 | 15547279 |
| transferable antibiotic resistance elements in haemophilus influenzae share a common evolutionary origin with a diverse family of syntenic genomic islands. | transferable antibiotic resistance in haemophilus influenzae was first detected in the early 1970s. after this, resistance spread rapidly worldwide and was shown to be transferred by a large 40- to 60-kb conjugative element. bioinformatics analysis of the complete sequence of a typical h. influenzae conjugative resistance element, icehin1056, revealed the shared evolutionary origin of this element. icehin1056 has homology to 20 contiguous sequences in the national center for biotechnology inform ... | 2004 | 15547285 |
| the n terminus of bacterial elongation factor tu elicits innate immunity in arabidopsis plants. | innate immunity is based on the recognition of pathogen-associated molecular patterns (pamps). here, we show that elongation factor tu (ef-tu), the most abundant bacterial protein, acts as a pamp in arabidopsis thaliana and other brassicaceae. ef-tu is highly conserved in all bacteria and is known to be n-acetylated in escherichia coli. arabidopsis plants specifically recognize the n terminus of the protein, and an n-acetylated peptide comprising the first 18 amino acids, termed elf18, is fully ... | 2004 | 15548740 |
| rar1 positively controls steady state levels of barley mla resistance proteins and enables sufficient mla6 accumulation for effective resistance. | the polymorphic barley (hordeum vulgare) mla locus harbors allelic race-specific resistance (r) genes to the powdery mildew fungus blumeria graminis f sp hordei. the highly sequence-related mla proteins contain an n-terminal coiled-coil structure, a central nucleotide binding (nb) site, a leu-rich repeat (lrr) region, and a c-terminal non-lrr region. using transgenic barley lines expressing epitope-tagged mla1 and mla6 derivatives driven by native regulatory sequences, we show a reversible and s ... | 2004 | 15548741 |
| antagonistic interaction between abscisic acid and jasmonate-ethylene signaling pathways modulates defense gene expression and disease resistance in arabidopsis. | the plant hormones abscisic acid (aba), jasmonic acid (ja), and ethylene are involved in diverse plant processes, including the regulation of gene expression during adaptive responses to abiotic and biotic stresses. previously, aba has been implicated in enhancing disease susceptibility in various plant species, but currently very little is known about the molecular mechanisms underlying this phenomenon. in this study, we obtained evidence that a complex interplay between aba and ja-ethylene sig ... | 2004 | 15548743 |
| identification and expression profiling of tomato genes differentially regulated during a resistance response to xanthomonas campestris pv. vesicatoria. | the gram-negative bacterium xanthomonas campestris pv. vesicatoria is the causal agent of spot disease in tomato and pepper. plants of the tomato line hawaii 7981 are resistant to race t3 of x. campestris pv. vesicatoria expressing the type iii effector protein avrxv3 and develop a typical hypersensitive response upon bacterial challenge. a combination of suppression subtractive hybridization and microarray analysis identified a large set of cdnas that are induced or repressed during the resista ... | 2004 | 15553246 |
| transcriptional regulation of components of the type iii secretion system and effectors in pseudomonas syringae pv. phaseolicola. | quantitative real-time polymerase chain reaction was used with specific taqman probes to examine transcription of selected hrp and effector genes in pseudomonas syringae pv. phaseolicola strains 1448a (race 6) and 1449b (race 7). transcripts examined were from genes encoding the regulators hrpr and hrpl, core structural components of the type iii secretion system (ttss) hrcc, hrcj, hrcn, hrcu, and hrpa; the first open-reading frame of each hrp operon, including hrpf, hrpj, hrpp, and hrpy, and al ... | 2004 | 15553250 |
| adaptation of the endogenous salmonella enterica serovar typhi clya-encoded hemolysin for antigen export enhances the immunogenicity of anthrax protective antigen domain 4 expressed by the attenuated live-vector vaccine strain cvd 908-htra. | bacterial live-vector vaccines aim to deliver foreign antigens to the immune system and induce protective immune responses, and surface-expressed or secreted antigens are generally more immunogenic than cytoplasmic constructs. we hypothesize that an optimum expression system will use an endogenous export system to avoid the need for large amounts of heterologous dna encoding additional proteins. here we describe the cryptic chromosomally encoded 34-kda cytolysin a hemolysin of salmonella enteric ... | 2004 | 15557633 |
| regulators encoded in the escherichia coli type iii secretion system 2 gene cluster influence expression of genes within the locus for enterocyte effacement in enterohemorrhagic e. coli o157:h7. | enterohemorrhagic escherichia coli (ehec) o157:h7 subverts host cells through a type iii secretion system encoded by the locus for enterocyte effacement (lee). genome sequencing of this pathotype revealed the existence of a gene cluster encoding components of a second cryptic type iii secretion system, e. coli type iii secretion system 2 (ett2). recently, we showed that the ett2 gene cluster is present in whole or in part in the majority of e. coli strains but is unable to encode a functional se ... | 2004 | 15557654 |
| pnuc and the utilization of the nicotinamide riboside analog 3-aminopyridine in haemophilus influenzae. | the utilization pathway for the uptake of nad and nicotinamide riboside was previously characterized for haemophilus influenzae. we now report on the cellular location, topology, and substrate specificity of pnuc. pnuc of h. influenzae is only distantly related to pnuc of escherichia coli and salmonella enterica serovar typhimurium. when e. coli pnuc was expressed in an h. influenzae pnuc mutant, it was able to take up only nicotinamide riboside and not nicotinamide mononucleotide. therefore, we ... | 2004 | 15561822 |
| inhibition of phosphoinositide-specific phospholipase c results in the induction of pathogenesis-related genes in soybean. | the inositol 1,4,5-trisphosphate (ip3) content is decreased in soybean cells following infection with pseudomonas syringae pv. glycinea (psg). in this investigation, a differential display approach was applied to isolate soybean genes that are transcriptionally up-regulated by the inhibition of phosphoinositide-specific phospholipase c (pi-plc) activity and to study if the transcription of those genes is altered following psg infection. four genes, transcriptionally activated following treatment ... | 2004 | 15570470 |
| use of pseudomonas putida esta as an anchoring motif for display of a periplasmic enzyme on the surface of escherichia coli. | the functional expression of proteins on the surface of bacteria has proven important for numerous biotechnological applications. in this report, we investigated the n-terminal fusion display of the periplasmic enzyme beta-lactamase (bla) on the surface of escherichia coli by using the translocator domain of the pseudomonas putida outer membrane esterase (esta), which is a member of the lipolytic autotransporter enzymes. to find out the transport function of a c-terminal domain of esta, we gener ... | 2004 | 15574889 |
| complete nucleotide sequence of the conjugative tetracycline resistance plasmid pfbaot6, a member of a group of incu plasmids with global ubiquity. | this study presents the first complete sequence of an incu plasmid, pfbaot6. this plasmid was originally isolated from a strain of aeromonas caviae from hospital effluent (westmorland general hospital, kendal, united kingdom) in september 1997 (g. rhodes, g. huys, j. swings, p. mcgann, m. hiney, p. smith, and r. w. pickup, appl. environ. microbiol. 66:3883-3890, 2000) and belongs to a group of related plasmids with global ubiquity. pfbaot6 is 84,748 bp long and has 94 predicted coding sequences, ... | 2004 | 15574953 |
| nucleotide sequences, genetic organization, and distribution of peu30 and pel60 from erwinia amylovora. | the nucleotide sequences, genetic organization, and distribution of plasmids peu30 (30,314 bp) and pel60 (60,145 bp) from the plant pathogen erwinia amylovora are described. the newly characterized peu30 and pel60 plasmids inhabited strains isolated in the western united states and lebanon, respectively. the gene content of peu30 resembled plasmids found in plant-associated bacteria, while that of pel60 was most similar to incl/m plasmids inhabiting enteric bacteria. | 2004 | 15574957 |
| role of chloroplast trienoic fatty acids in plant disease defense responses. | trienoic fatty acids (tas) are the major polyunsaturated fatty acid species in the membrane lipids in plant cells. tas are crucial for the adaptation to abiotic stresses, especially low- or high-temperature stress. we show that tas in chloroplast membrane lipids are involved in defense responses against avirulent bacterial pathogens. avirulent pathogen invasion of plants induces a transient production of reactive oxygen intermediates (roi), programmed cell death and subsequent disease resistance ... | 2004 | 15584958 |
| mutations in pmr5 result in powdery mildew resistance and altered cell wall composition. | powdery mildews and other obligate biotrophic pathogens are highly adapted to their hosts and often show limited host ranges. one facet of such host specialization is likely to be penetration of the host cell wall, a major barrier to infection. a mutation in the pmr5 gene rendered arabidopsis resistant to the powdery mildew species erysiphe cichoracearum and erysiphe orontii, but not to the unrelated pathogens pseudomonas syringae or peronospora parasitica. pmr5 belongs to a large family of plan ... | 2004 | 15584961 |
| pseudomonas type iii effector avrpto suppresses the programmed cell death induced by two nonhost pathogens in nicotiana benthamiana and tomato. | many gram-negative bacterial pathogens rely on a type iii secretion system to deliver a number of effector proteins into the host cell. though a number of these effectors have been shown to contribute to bacterial pathogenicity, their functions remain elusive. here we report that avrpto, an effector known for its ability to interact with pto and induce pto-mediated disease resistance, inhibited the hypersensitive response (hr) induced by nonhost pathogen interactions. pseudomonas syringae pv. to ... | 2004 | 15597738 |
| functional analysis of avr9/cf-9 rapidly elicited genes identifies a protein kinase, acik1, that is essential for full cf-9-dependent disease resistance in tomato. | tomato (lycopersicon esculentum) cf genes confer resistance to the fungal pathogen cladosporium fulvum through recognition of secreted avirulence (avr) peptides. plant defense responses, including rapid alterations in gene expression, are immediately activated upon perception of the pathogen. previously, we identified a collection of avr9/cf-9 rapidly (15 to 30 min) elicited (acre) genes from tobacco (nicotiana tabacum). many of the acre genes encode putative signaling components and thus may pl ... | 2004 | 15598806 |
| the abi2-dependent abscisic acid signalling controls hrpn-induced drought tolerance in arabidopsis. | hrpn, a protein produced by the plant pathogenic bacterium erwinia amylovora, has been shown to stimulate plant growth and resistance to pathogens and insects. here we report that hrpn activates abscisic acid (aba) signalling to induce drought tolerance (dt) in arabidopsis thaliana l. plants grown with water stress. spraying wild-type plants with hrpn-promoted stomatal closure decreased leaf transpiration rate, increased moisture and proline levels in leaves, and alleviated extents of damage to ... | 2004 | 15599761 |
| impact of muts inactivation on foreign dna acquisition by natural transformation in pseudomonas stutzeri. | in prokaryotic mismatch repair the muts protein and its homologs recognize the mismatches. the muts gene of naturally transformable pseudomonas stutzeri atcc 17587 (genomovar 2) was identified and characterized. the deduced amino acid sequence (859 amino acids; 95.6 kda) displayed protein domains i to iv and a mismatch-binding motif similar to those in muts of escherichia coli. a muts::aac mutant showed 20- to 163-fold-greater spontaneous mutability. transformation experiments with dna fragments ... | 2005 | 15601698 |
| regulation of the pseudomonas sp. strain adp cyanuric acid degradation operon. | pseudomonas sp. strain adp is the model strain for studying bacterial degradation of the s-triazine herbicide atrazine. in this work, we focused on the expression of the atzdef operon, involved in mineralization of the central intermediate of the pathway, cyanuric acid. expression analysis of atzd-lacz fusions in pseudomonas sp. strain adp and pseudomonas putida showed that atzdef is subjected to dual regulation in response to nitrogen limitation and cyanuric acid. the gene adjacent to atzd, orf ... | 2005 | 15601699 |
| 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 |
| crosstalk and differential response to abiotic and biotic stressors reflected at the transcriptional level of effector genes from secondary metabolism. | plant secondary metabolism significantly contributes to defensive measures against adverse abiotic and biotic cues. to investigate stress-induced, transcriptional alterations of underlying effector gene families, which encode enzymes acting consecutively in secondary metabolism and defense reactions, a dna array (metarray) harboring gene-specific probes was established. it comprised complete sets of genes encoding 109 secondary product glycosyltransferases and 63 glutathione-utilizing enzymes al ... | 2004 | 15604654 |
| the ethylene-responsive factor like protein 1 (caerflp1) of hot pepper (capsicum annuum l.) interacts in vitro with both gcc and dre/crt sequences with different binding affinities: possible biological roles of caerflp1 in response to pathogen infection and high salinity conditions in transgenic tobacco plants. | from a pathogen-inoculated hot pepper (capsicum annuum l. cv. pukang) leaf est, we identified a cdna clone, pcaerflp1, encoding a putative transcription factor that contains a single erf/ap2 dna binding domain. caerflp1 was most closely related to tomato leerf2 (73%), both of which belong to the novel erf class iv typified by the n-terminal mcggail signature sequence, while it had a limited sequence identity (25-30%) with arabidopsis aterfs and tobacco nterfs. quantitative gel retardation assays ... | 2004 | 15604665 |
| 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 |
| cazfp1, cys2/his2-type zinc-finger transcription factor gene functions as a pathogen-induced early-defense gene in capsicum annuum. | a pepper zinc-finger protein gene, cazfp1 , encoding the cys2/his2-type zinc-finger transcription factor was isolated from pepper leaves inoculated with an avirulent strain bv5-4a of xanthomonas campestris pv. vesicatoria . the cazfp1 protein is a nuclear targeting protein, which functions as a transcriptional regulator. the full-length cazfp1 had no transcriptional activation activity, whereas the c-terminal region of cazfp1 had transactivation activity. the cazfp1 transcripts were constitutive ... | 2004 | 15604723 |
| structure of the core oligosaccharide of a rough-type lipopolysaccharide of pseudomonas syringae pv. phaseolicola. | the core structure of the lipopolysaccharide (lps) isolated from a rough strain of the phytopathogenic bacterium pseudomonas syringae pv. phaseolicola, gspb 711, was investigated by sugar and methylation analyses, fourier transform ion-cyclotron resonance esi ms, and one- and two-dimensional 1h-, 13c- and 31p-nmr spectroscopy. strong alkaline deacylation of the lps resulted in two core-lipid a backbone undecasaccharide pentakisphosphates in the ratio approximately 2.5 : 1, which corresponded to ... | 2004 | 15606785 |
| pseudomonas aeruginosa genome database and pseudocap: facilitating community-based, continually updated, genome annotation. | using the pseudomonas aeruginosa genome project as a test case, we have developed a database and submission system to facilitate a community-based approach to continually updated genome annotation (http://www.pseudomonas.com). researchers submit proposed annotation updates through one of three web-based form options which are then subjected to review, and if accepted, entered into both the database and log file of updates with author acknowledgement. in addition, a coordinator continually review ... | 2005 | 15608211 |
| pseudomonas aeruginosa genome database and pseudocap: facilitating community-based, continually updated, genome annotation. | using the pseudomonas aeruginosa genome project as a test case, we have developed a database and submission system to facilitate a community-based approach to continually updated genome annotation (http://www.pseudomonas.com). researchers submit proposed annotation updates through one of three web-based form options which are then subjected to review, and if accepted, entered into both the database and log file of updates with author acknowledgement. in addition, a coordinator continually review ... | 2005 | 15608211 |
| tractor_db: a database of regulatory networks in gamma-proteobacterial genomes. | experimental data on the escherichia coli transcriptional regulatory system has been used in the past years to predict new regulatory elements (promoters, transcription factors (tfs), tfs' binding sites and operons) within its genome. as more genomes of gamma-proteobacteria are being sequenced, the prediction of these elements in a growing number of organisms has become more feasible, as a step towards the study of how different bacteria respond to environmental changes at the level of transcrip ... | 2005 | 15608293 |