Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| new host plants of erwinia amylovora in bulgaria. | nine strains of erwinia amylovora were isolated from new host plants in bulgaria--chokeberry and strawberry. the strains were characterized morphologically and biochemically using the api 20e and biolog system. it was established that they showed three different api 20e metabolic profiles, not found by previous studies of e. amylovora. all strains were identified as e. amylovora due to their metabolic fingerprint patterns obtained by the biolog system. the identification was confirmed by pcr amp ... | 2005 | 16402550 |
| identification of the central quorum sensing regulator of virulence in the enteric phytopathogen, erwinia carotovora: the virr repressor. | in the gram-negative phytopathogen, erwinia carotovora ssp. atroseptica (eca) virulence depends on the production of a n-(3-oxohexanoyl)-l-homoserine lactone (ohhl) quorum sensing (qs) signal. this work identifies the elusive 'missing link' between qs and virulence in erwinia. we have identified and characterized a novel regulator of virulence, virr, in eca and show that a virr mutation completely restores virulence factor production to an eca mutant unable to synthesize ohhl. this effect of the ... | 2006 | 16359322 |
| [enhanced resistance to phytopathogenic bacteria in transgenic tobacco plants with synthetic gene of antimicrobial peptide cecropin p1]. | plasmids with a synthetic gene of the mammalian antimicrobial peptide cecropin p1 (cecp1) controlled by the constitutive promoter 35s rna of cauliflower mosaic virus were constructed. agrobacterial transformation of tobacco plants was conducted using the obtained recombinant binary vector. the presence of gene cecp1 in the plant genome was confirmed by pcr. the expression of gene cecp1 in transgenic plants was shown by northern blot analysis. the obtained transgenic plants exhibit enhanced resis ... | 2005 | 16358711 |
| pecs and pect coregulate the synthesis of hrpn and pectate lyases, two virulence determinants in erwinia chrysanthemi 3937. | erwinia chrysanthemi strain 3937 is a necrotrophic bacterial plant pathogen. pectinolytic enzymes and, in particular, pectate lyases play a key role in soft rot symptoms; however, the efficient colonization of plants by e. chrysanthemi requires additional factors. these factors include hrpn (harpin), a heat-stable, glycine-rich hydrophilic protein, which is secreted by the type iii secretion system. we investigated the expression of hrpn in e. chrysanthemi 3937 in various environmental condition ... | 2005 | 16353555 |
| formation of the blue pigment indigoidine by phytopathogenic erwinia. | most cultures belonging to the "erwinia chrysanthemi group" of soft-rot bacteria form traces of a blue, extracellular, water-insoluble pigment. this pigment is generally not found in cultures of the other members of the genus erwinia. the blue substance has been isolated and purified from three members of the e. chrysanthemi group; it has been identified as indigoidine, 5,5'-diamino-4,4'-dihydroxy-3,3'-diazadiphenoquinone-(2,2'). | 1966 | 16349687 |
| beta-glucosidase activity in phytopathogenic bacteria. | most of 58 isolates of phytopathogenic and related bacteria comprising 24 species in the genera agrobacterium, erwinia, corynebacterium, pseudomonas, and xanthomonas exhibited beta-glucosidase activity, especially the gall-nonforming pathogenic pseudomonads and soft rot organisms. the gall-forming pseudomonads and p. fluorescens exhibited no beta-glucosidase activity, with the exception of one isolate of p. savastanoi which showed slight activity on an inorganic nitrogen-arbutin medium. the best ... | 1964 | 16349648 |
| ribotyping of erwinia chrysanthemi strains in relation to their pathogenic and geographic distribution. | 16s and 23s rrnas from escherichia coli were used to study the relationship among a representative collection of strains of erwinia chrysanthemi differing in their original host and geographical origin. phenetic analysis of restriction fragment length polymorphisms allowed the distribution of the studied strains into seven clusters. these clusters were similar to those obtained by cladistic methods and appeared to correlate well with the established pathovars and biovars but to a lesser extent w ... | 1994 | 16349416 |
| derivation of mutants of erwinia carotovora subsp. betavasculorum deficient in export of pectolytic enzymes with potential for biological control of potato soft rot. | erwinia carotovora subsp. betavasculorum ecb168 produces an antibiotic(s) that suppresses growth of the related bacterium erwinia carotovora subsp. carotovora in culture and in wounds of potato tubers. strain ecb168 also produces and secretes pectolytic enzymes and causes a vascular necrosis and root rot of sugar beet. genes (out) involved in secretion of pectolytic enzymes by ecb168 were localized to two hindiii fragments (8.5 and 10.5 kb) of ecb168 genomic dna by hybridization to the cloned ou ... | 1994 | 16349316 |
| characterization of monoclonal antibodies specific for erwinia carotovora subsp. atroseptica and comparison of serological methods for its sensitive detection on potato tubers. | seven monoclonal antibodies (mabs) to erwinia carotovora subsp. atroseptica have been produced. one, called 4g4, reacted with high specificity for serogroup i of e. carotovora subsp. atroseptica, the most common serogroup on potato tubers in different serological assays. eighty-six strains belonging to different e. carotovora subsp. atroseptica serogroups were assayed. some strains of serogroup xxii also reacted positively. no cross-reactions were observed against other species of plant pathogen ... | 1994 | 16349293 |
| a role for exopolysaccharides in the protection of microorganisms from desiccation. | mucoid strains of escherichia coli, acinetobacter calcoaceticus, and erwinia stewartii were significantly more resistant to desiccation than corresponding isogenic nonmucoid mutants (survival rates of up to 35% in mucoid strains and between 0.7 and 5% in nonmucoid variants), even in colonies containing both cell types. desiccation was found to bring about an induction of beta-galactosidase in lon strains of e. coli k-12 carrying transcriptional lac fusions in the capsule biosynthetic (cps) regul ... | 1994 | 16349202 |
| two genomic regions involved in catechol siderophore production by erwinia carotovora. | two regions involved in catechol biosynthesis (cbs) of erwinia carotovora w3c105 were cloned by functional complementation of escherichia coli mutants that were deficient in the biosynthesis of the catechol siderophore enterobactin (ent). a 4.3-kb region of genomic dna of e. carotovora complemented the entb402 mutation of e. coli. a second genomic region of 12.8 kb complemented entd, entc147, ente405, and enta403 mutations of e. coli. although functions encoded by catechol biosynthesis genes (cb ... | 1994 | 16349193 |
| anaerobic nitrate respiration by erwinia carotovora subsp. atroseptica during potato tuber invasion. | the in planta induction of anaerobic nitrate respiration by erwinia carotovora subsp. atroseptica in relation to the in situ oxygen status in soft rotting potato tubers has been investigated. in vitro experiments have shown that nitrate was required for the induction of respiratory nitrate reductase activity in e. carotovora. in addition, oxygen was found to repress this activity. expression of respiratory nitrate reductase was found in e. carotovora cells extracted from soft rotting potato tube ... | 1993 | 16349082 |
| erwinia chrysanthemi ec16 produces a second set of plant-inducible pectate lyase isozymes. | the enterobacterium erwinia chrysanthemi causes soft-rot diseases involving extensive tissue maceration in a wide variety of plants and secretes multiple pectic enzymes that degrade plant cell walls and middle lamellae. an e. chrysanthemi mutant with directed deletions or insertions in genes pehx, pelx, pela, pelb, pelc, and pele, which encode exo-poly-alpha-d-galacturonosidase, exopolygalacturonate lyase, and four isozymes of pectate lyase, respectively, was constructed by the marker exchange o ... | 1993 | 16348952 |
| isolation and characterization of microorganisms associated with the traditional sorghum fermentation for production of sudanese kisra. | sorghum flour obtained from sudan was mixed with water in a 1:2 (wt/vol) ratio and fermented at 30 degrees c for 24 h. the bacterial populations increased with fermentation time and reached a plateau at approximately 18 h. at the end of 24 h, sorghum batter ph had dropped from 5.95 to 3.95 and the batter had a lactic acid content of 0.80%. the microbial population during the 24 h of fermentation consisted of bacteria (pediococcus pentosaceus, lactobacillus confusus, lactobacillus brevis, lactoba ... | 1991 | 16348551 |
| rapid in situ assay for indoleacetic acid production by bacteria immobilized on a nitrocellulose membrane. | we have developed a new assay that differentiates between indoleacetic acid (iaa)-producing and -nonproducing bacteria on a colony plate lift. medium supplemented with 5 mm l-tryptophan is inoculated with isolates of interest, overlaid with a nitrocellulose membrane, and then incubated until bacterial colonies reach 1 to 2 mm in diameter. the membrane is removed to a filter paper saturated with salkowski reagent and incubated until distinct red haloes form around the colonies. the colorimetric r ... | 1991 | 16348419 |
| evaluation of methods for sampling, recovery, and enumeration of bacteria applied to the phylloplane. | determining the fate and survival of genetically engineered microorganisms released into the environment requires the development and application of accurate and practical methods of detection and enumeration. several experiments were performed to examine quantitative recovery methods that are commonly used or that have potential applications. in these experiments, erwinia herbicola and enterobacter cloacae were applied in greenhouses to blue lake bush beans (phaseolus vulgaris) and cayuse oats ... | 1991 | 16348404 |
| genetically engineered erwinia carotovora: survival, intraspecific competition, and effects upon selected bacterial genera. | environmental use of genetically engineered microorganisms has raised concerns about potential ecological impact. this research evaluated the survival, competitiveness, and effects upon selected bacterial genera of wild-type and genetically engineered erwinia carotovora subsp. carotovora to ascertain if differences between the wild-type and genetically engineered strains exist in soil microcosms. the engineered strain contained a chromosomally inserted gene for kanamycin resistance. no significa ... | 1990 | 16348212 |
| characterization of rhizobacteria associated with weed seedlings. | rhizobacteria were isolated from seedlings of seven economically important weeds and characterized for potential phytopathogenicity, effects on seedling growth, and antibiosis to assess the possibility of developing deleterious rhizobacteria as biological control agents. the abundance and composition of rhizobacteria varied among the different weed species. for example, fluorescent pseudomonads represented from 11 to 42% of the total rhizobacterial populations from jimsonweed and lambsquarters, ... | 1990 | 16348208 |
| acetic acid bacterial biota of the pink sugar cane mealybug, saccharococcus sacchari, and its environs. | saccharococcus sacchari is the primary colonizer of the developing "sterile" tissue between the leaf sheath and stem of sugar cane. the honeydew secreted by the mealybugs is acidic (about ph 3) and supports an atypical epiphytic microbiota dominated by acetobacter-like bacteria and acidophilic yeast species. however, erwinia and leuconostoc species predominate within the leaf sheath pocket region when the mealybugs die out. the unidentified acetobacters were readily isolated from s. sacchari thr ... | 1990 | 16348144 |
| genetically engineered erwinia carotovora in aquatic microcosms: survival and effects on functional groups of indigenous bacteria. | the survival of genetically engineered erwinia carotovora l-864, with a kanamycin resistance gene inserted in its chromosome, was monitored in the water and sediment of aquatic microcosms. the density of genetically engineered and wild-type e. carotovora strains declined at the same rate, falling in 32 days below the level of detection by viable counts. we examined the impact of the addition of genetically engineered and wild-type strains on indigenous bacteria belonging to specific functional g ... | 1989 | 16347942 |
| identification of erwinia amylovora, the fireblight pathogen, by colony hybridization with dna from plasmid pea29. | all strains of erwinia amylovora characterized carry a medium-size plasmid of 29 kilobases (pea29). we mapped this plasmid with various restriction enzymes, cloned the whole dna into an escherichia coli plasmid, and subcloned restriction fragments. these dna species were used for identification of e. amylovora after handling of strains in the laboratory and also in field isolates. about 70 strains of e. amylovora and 24 strains from nine other species, mainly found in plant habitats, were checke ... | 1988 | 16347778 |
| role of antibiosis in competition of erwinia strains in potato infection courts. | [this corrects the article on p. 1225 in vol. 54.]. | 1988 | 16347764 |
| conversion of glucose to 2-keto-l-gulonate, an intermediate in l-ascorbate synthesis, by a recombinant strain of erwinia citreus. | a gene for 2,5-diketo-d-gluconate (25dkg) reductase, which encodes an enzyme composed of 277 amino acid residues catalyzing the reduction of 25dkg to 2-keto-l-gulonate (2klg), was cloned from corynebacterium sp. strain shs752001 and expressed in erwinia citreus shs2003, a strain which oxidizes glucose to 25dkg. the recombinant microorganism converted glucose to 2klg, a compound which can be readily converted to l-ascorbate (vitamin c). improvements in the yield of 2klg were obtained by changing ... | 1988 | 16347687 |
| role of antibiosis in competition of erwinia strains in potato infection courts. | erwinia carotovora subsp. betavasculorum strains produced a bactericidal antibiotic in vitro that inhibited a wide spectrum of gram-negative and gram-positive bacteria. the optimum temperature for production was 24 degrees c, and the addition of glycerol to culture media enhanced antibiotic production. antibiotic production by these strains in the infection court of potato was the principal determinant enabling it to gain ascendancy over competing antibiotic-sensitive erwinia carotovora subsp. c ... | 1988 | 16347633 |
| competitive exclusion of epiphytic bacteria by icepseudomonas syringae mutants. | the growth of ice nucleation-active and near-isogenic ice nucleation-deficient (ice) pseudomonas syringae strains coexisting on leaf surfaces was examined to determine whether competition was sufficient to account for antagonism of phylloplane bacteria. the ice nucleation frequency spectra of 46 icep. syringae mutants, obtained after mutagenesis with ethyl methanesulfonate, differed both quantitatively and qualitatively, but the mutants could be grouped into four distinct phenotypic classes. the ... | 1987 | 16347468 |
| multiplication and virulence in plant tissues of escherichia coli clones producing pectate lyase isozymes plb and ple at high levels and of an erwinia chrysanthemi mutant deficient in ple. | the phytopathogenic enterobacterium erwinia chrysanthemi strain ec16 produces four isozymes of pectate lyase (pl), an extracellular enzyme that macerates parenchymatous plant tissues and kills plant cells. a 1.8-kilobase ecori dna fragment containing the entire pele gene was deleted from the e. chrysanthemi chromosome by marker exchange of a cloned fragment that had been modified in vitro. the resulting mutant, um1001, produced the isozymes pla, plb, and plc, but not ple. mutant um1001 was compa ... | 1987 | 16347452 |
| fermentation of d-xylose and l-arabinose to ethanol by erwinia chrysanthemi. | erwinia spp. are gram-negative facultative anaerobes within the family enterobacteriacae which possess several desirable traits for the conversion of pentose sugars to ethanol, such as the ability to ferment a broad range of carbohydrates and the ease with which they can be genetically modified. twenty-eight strains of erwinia carotovora and e. chrysanthemi were screened for the ability to ferment d-xylose to ethanol. e. chrysanthemi b374 was chosen for further study on the basis of its superior ... | 1987 | 16347426 |
| a rapid procedure for purifying pectate lyase from erwinia carotovora based on substrate affinity. | to purify pectate lyase produced by erwinia carotovora subsp. carotovora, we used the supernatant from 48-h-old cultures grown in broth containing sodium polypectate and yeast extract. the supernatant was combined with the enzyme substrates sodium polypectate and polygalacturonic acid, which were then precipitated with cacl(2). after the precipitate was washed, pectate lyase was eluted with 1.0 m nacl. | 1987 | 16347348 |
| effect of increased beta-glucosidase activity on virulence of erwinia amylovora. | plant tissues often contain beta-glucosides that can be enzymatically hydrolyzed to produce toxic aglycones. it has been suggested that the low beta-glucosidase activity found in erwinia amylovora contributes to bacterial virulence by allowing the bacteria to infect plants that contain beta-glucosides without inducing the formation of toxic aglycones. to test this suggestion, we created strains of e. amylovora which had high beta-glucosidase activities and studied the ability of these strains to ... | 1987 | 16347316 |
| antagonism of lactic acid bacteria against phytopathogenic bacteria. | a variety of lactic acid bacteria, isolated from plant surfaces and plant-associated products, were found to be antagonistic to test strains of the phytopathogens xanthomonas campestris, erwinia carotovora, and pseudomonas syringae. effective "in vitro" inhibition was found both on agar plates and in broth cultures. in pot trials, treatment of bean plants with a lactobacillus plantarum strain before inoculation with p. syringae caused a significant reduction of the disease incidence. | 1986 | 16347150 |
| cloning and expression in escherichia coli of the polysaccharide depolymerase associated with bacteriophage-infected erwinia amylovora. | the bacteriophage-encoded polysaccharide depolymerase produced in erwinia amylovora has been cloned and expressed in escherichia coli. the bacteriophage era103 genome was observed to consist of five ecori fragments, labeled as follows: a, 7.5 kilobases (kb); b, 5.0 kb; c, 2.7 kb; d, 2.1 kb; and e, 1.8 kb. a restriction map for era103 was also prepared. each of the fragments were cloned into the positive-selection vector pop203(a(2)) and pbr322. | 1986 | 16347044 |
| activity stain for rapid characterization of pectic enzymes in isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gels. | a system was developed for the rapid characterization of microbial pectic enzyme complexes and then tested on erwinia chrysanthemi and sclerotium rolfsii. pectic enzymes in minute samples of crude culture filtrates were resolved by ultrathin-layer polyacrylamide gel isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then assayed with an ultrathin pectate-agarose overlay stained with ruthenium red. the simple procedure can be completed within 30 min after isoel ... | 1985 | 16346881 |
| partial purification and characterization of a polysaccharide depolymerase associated with phage-infected erwinia amylovora. | erwinia amylovora infected with bacteriophage era103 produced an enzyme which degraded the extracellular polysaccharide of noninfected cells. the depolymerase enzyme was purified 15-fold by a procedure which included ammonium sulfate precipitation, ultracentrifugation, cm-sephadex batchwise separation, sephadex g-50 column chromatography, and sephacryl s-200 column chromatography. the enzyme had a molecular weight of approximately 21,000 and a ph optimum of 6.0. activity was enhanced by suppleme ... | 1985 | 16346774 |
| effect of culture conditions on the production of tyrosine phenol-lyase by erwinia herbicola. | the effect of environmental parameters on the growth and the tyrosine phenol-lyase content of erwinia herbicola was investigated. on mineral medium containing glycerol, l-tyrosine increased the enzyme content 23-fold. when the l-tyrosine was also the carbon source, bacterial growth was 300 times greater than the basal level. on a rich medium, tyrosine phenol-lyase production was strongly dependent on ph and aeration. catabolite repression and induction both probably control enzyme content. | 1984 | 16346688 |
| toxicity of smoke to epiphytic ice nucleation-active bacteria. | wheat straw smoke aerosols and liquid smoke condensates reduced significantly both the viability and the ice-nucleating activity of pseudomonas syringae pv. syringae and erwinia herbicola in vitro and on leaf surfaces in vivo. highly significant reductions in numbers of bacterial ice nuclei on the surface of both corn and almond were observed after exposure to smoke aerosols. at -5 degrees c, frost injury to corn seedlings colonized by ice nucleation-active bacteria was reduced after exposure to ... | 1983 | 16346333 |
| tn5-induced mutations in the enterobacterial phytopathogen erwinia chrysanthemi. | escherichia coli (2492/pjb4ji) matings with erwinia chrysanthemi produced kanamycin resistant (km) transconjugants, a majority of which were gentamicin sensitive (gm). a small proportion (about 0.8%) of the km gm clones were either auxotrophic or failed to catabolize galacturonate (gtu). the r plasmid (pjb4ji) dna was detected in the parent e. coli strain and in a km gm transconjugant, but not in km gme. chrysanthemi strains carrying tn5-induced mutations. in hfr crosses, km (tn5) was found link ... | 1983 | 16346212 |
| nitrous oxide production by organisms other than nitrifiers or denitrifiers. | heterotrophic bacteria, yeasts, fungi, plants, and animal breath were investigated as possible sources of n(2)o. microbes found to produce n(2)o from no(3) but not consume it were: (i) all of the nitrate-respiring bacteria examined, including strains of escherichia, serratia, klebsiella, enterobacter, erwinia, and bacillus; (ii) one of the assimilatory nitrate-reducing bacteria examined, azotobacter vinelandii, but not azotobacter macrocytogenes or acinetobacter sp.; and (iii) some but not all o ... | 1982 | 16346152 |
| production of 2-keto-l-gulonic acid from d-glucose by two-stage fermentation. | a practical method for the production of calcium 2-keto-l-gulonate (an intermediate in the reichstein synthesis of l-ascorbic acid) from d-glucose has been established by using a two-stage fermentation system. d-glucose was first converted to calcium 2,5-diketo-d-gluconate by a mutant strain of erwinia sp. in a medium containing d-glucose, corn steep liquor, (nh(4))(2)hpo(4), and caco(3). after a 26-h cultivation, 328.6 mg of calcium 2,5-diketo-d-gluconate per ml was obtained, with a 94.5% yield ... | 1982 | 16346005 |
| bacterial culture preservation in frozen and dry-film methylcellulose. | forty-seven of 61 bacterial cultures, including strains of pseudomonas, xanthomonas, erwinia, agrobacterium, corynebacterium, serratia, klebsiella, and escherichia, remained viable after storage in frozen methylcellulose or in dried methylcellulose for up to 38 months. pathogenicity remained intact for those strains tested. bacteria were grown on a solid medium and then removed and placed in 1.0% methylcellulose (cellulose methyl ether) to make a final suspension of 10 colony-forming units (cfu) ... | 1981 | 16345889 |
| agglutination of erwinia stewartii strains with a corn agglutinin: correlation with extracellular polysaccharide production and pathogenicity. | a bacterial agglutinin was extracted from ground corn (wi hybrid 64a x w117) seed with phosphate-buffered saline (ph 6.0) and precipitated with (nh(4))(2)so(4) at 70% saturation. the activities of this agglutinin against 22 strains of erwinia stewartii (agent of bacterial wilt of corn) that varied in virulence were determined. specific agglutination (agglutination titer per milligram of protein per milliliter) values were correlated negatively with virulence ratings. strains with high specific a ... | 1981 | 16345833 |
| fine structure of extracellular polysaccharide of erwinia amylovora. | virulent e(9) and avirulent e(8) strains of erwinia amylovora were shown by means of light, transmission, and scanning microscopy to be, respectively, encapsulated and unencapsulated. difficulty was encountered in stabilizing the fibrillar-appearing capsular extracellular polysaccharide. we suggest that the ephemeral nature of extracellular polysaccharide is due to the collapse of its extended structure upon dehydration. this occurs when bacteria are prepared for either transmission or scanning ... | 1980 | 16345638 |
| extracellular polysaccharide of erwinia amylovora: a correlation with virulence. | the extracellular polysaccharides produced as slime or capsule layers by bacterial pathogens of animals and plants have been often implicated as factors essential to pathogenesis. in the present study, virulence of the plant pathogen erwinia amylovora was correlated with the ability to produce extracellular polysaccharide (eps). eps production by a series of field isolates and bacterio-phage-resistant mutants differing in the extent to which they cause symptoms in host tissues was examined by qu ... | 1979 | 16345446 |
| acetylene reduction (nitrogen fixation) by enterobacteriaceae isolated from paper mill process waters. | using selective media containing galactitol, over 130 enterobacteriaceae have been isolated from paper mill process waters collected from different localities. these bacteria were extensively characterized and tested for acetylene-reducing (nitrogen-fixing) activity under anaerobic conditions. high activity was found in representatives of klebsiella pneumoniae, enterobacter aerogenes, enterobacter cloacae, erwinia herbicola, citrobacter freundii, citrobacter intermedius, and escherichia coli. un ... | 1976 | 16345168 |
| activation of defense responses in chinese cabbage by a nonhost pathogen, pseudomonas syringae pv. tomato. | pseudomonas syringae pv. tomato (pst) causes a bacterial speck disease in tomato and arabidopsis. in chinese cabbage, in which host-pathogen interactions are not well understood, pst does not cause disease but rather elicits a hypersensitive response. pst induces localized cell death and h2o2 accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. pre-inoculation with pst was found to induce resistance to erwinia carotovora subsp. carotovora, a pathogen that causes soft r ... | 2005 | 16336791 |
| two novel bacterial biosensors for detection of nitrate availability in the rhizosphere. | the nitrate-regulated promoter of narg in escherichia coli was fused to promoterless ice nucleation (inaz) and green fluorescent protein (gfp) reporter genes to yield the nitrate-responsive gene fusions in plasmids pnice and pngfp, respectively. while the promoter of narg is normally nitrate responsive only under anaerobic conditions, the l28h-fnr gene was provided in trans to enable nitrate-dependent expression of these reporter gene fusions even under aerobic conditions in both e. coli dh5alph ... | 2005 | 16332845 |
| diversity of carotenoid synthesis gene clusters from environmental enterobacteriaceae strains. | eight enterobacteriaceae strains that produce zeaxanthin and derivatives of this compound were isolated from a variety of environmental samples. phylogenetic analysis showed that these strains grouped with different clusters of erwinia type strains. four strains representing the phylogenetic diversity were chosen for further characterization, which revealed their genetic diversity as well as their biochemical diversity. the carotenoid synthesis gene clusters cloned from the four strains had thre ... | 2005 | 16332796 |
| transgenic ice nucleation-active enterobacter cloacae reduces cold hardiness of corn borer and cotton bollworm larvae. | the ice nucleation (in) gene icea of erwinia ananas 110 was integrated into the chromosomes of two enterobacter cloacae strains (enc1.2022 and enc1.181). these two newly derived transgenic strains, designated enc2022-i and enc181-i, respectively, possessed ice nucleation activity at -2.5 degrees c, significantly higher than their parent strains (active at approx -10 degrees c or lower). after ingesting these transgenic bacteria, the mean supercooling points (scps) of corn borer and cotton bollwo ... | 2004 | 16329857 |
| fermentation of 10% (w/v) sugar to d: (-)-lactate by engineered escherichia coli b. | derivatives of ethanologenic escherichia coli k011 were constructed for d: (-)-lactate production by deleting genes encoding competing pathways followed by metabolic evolution, a growth-based selection for mutants with improved performance. resulting strains, sz132 and sz186, contain native genes for sucrose utilization. no foreign genes are present in sz186. strain sz132 also contains a chromosomally integrated endoglucanase gene (erwinia chrysanthemi cely). strain sz132 produced over 1 mol lac ... | 2005 | 16328986 |
| cloning, sequencing, and heterologous expression of an erwinia cypripedii 314b lactonase specific for l-alpha-hydroxyglutaric acid gamma-lactone. | the gene for a lactonase that stereospecifically hydrolyzes (s)-5-oxo-2-tetrahydrofurancarboxylic acid to l-alpha-hydroxyglutaric acid was isolated from erwinia cypripedii 314b. determination of the nucleotide sequence showed that the gene consists of a single open reading frame of 1,152 bp that encodes a 383-amino-acid protein. comparison of the sequence of the predicted protein to that of the enzyme purified from e. cypripedii 314b revealed an n-terminal signal sequence of 19 amino acids. the ... | 2006 | 16328442 |
| the molecular structure and catalytic mechanism of a quorum-quenching n-acyl-l-homoserine lactone hydrolase. | in many gram-negative bacteria, including a number of pathogens such as pseudomonas aeruginosa and erwinia carotovora, virulence factor production and biofilm formation are linked to the quorum-sensing systems that use diffusible n-acyl-l-homoserine lactones (ahls) as intercellular messenger molecules. a number of organisms also contain genes coding for lactonases that hydrolyze ahls into inactive products, thereby blocking the quorum-sensing systems. consequently, these enzymes attract intense ... | 2005 | 16314577 |
| ca2+-dependent lipid binding and membrane integration of popa, a harpin-like elicitor of the hypersensitive response in tobacco. | popa is released by type iii secretion from the bacterial plant pathogen ralstonia solanacearum and triggers the hypersensitive response (hr) in tobacco. the function of popa remains obscure, mainly because mutants lacking this protein are not altered in their ability to interact with plants. in an attempt to identify the site of popa activity in plant cells, we generated transgenic tobacco plants expressing the popa gene under the control of an inducible promoter. immunocytologic analysis revea ... | 2005 | 16313625 |
| minimal residual disease (mrd) measurement as a tool to compare the efficacy of chemotherapeutic drug regimens using escherichia coli-asparaginase or erwinia-asparaginase in childhood acute lymphoblastic leukemia (all). | l-asparaginase is a crucial drug in childhood acute lymphoblastic leukemia (all) induction therapy, but much debate remains regarding the optimal formulation and dosage. as minimal residual disease (mrd) can accurately measure extremely low levels of lymphoblasts, it is a sensitive reflection of leukemia cell kill. we utilized mrd to compare the efficacy of erwinia-asparaginase (erwinia-asp) and e. coli-asparaginase (e. coli-asp) during induction therapy for childhood all. | 2006 | 16302217 |
| reliability of diagnostic techniques for erwinia amylovora, the causative agent of fire blight disease. | a total of 20 putative strains of erwinia amylovora originating from 11 samples of host plants with symptoms of fire blight were analyzed in detail using commercial polyclonal antibodies in immunochemical tests. fourteen strains reacted negatively in all tests; 6 strains reacted positively with a polyclonal antibody for pta-elisa (plate-trapped antigen-enzyme linked immunosorbent assay) at a concentration corresponding to a620 = 0.1, while at a620 readings of 0.01 and 0.001 the results were nega ... | 2005 | 16295660 |
| identification of erwinia amylovora genes induced during infection of immature pear tissue. | the enterobacterium erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. in this study, we used a modified in vivo expression technology system to identify e. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. we identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes a ... | 2005 | 16291682 |
| comparative analysis of two classes of quorum-sensing signaling systems that control production of extracellular proteins and secondary metabolites in erwinia carotovora subspecies. | in erwinia carotovora subspecies, n-acyl homoserine lactone (ahl) controls the expression of various traits, including extracellular enzyme/protein production and pathogenicity. we report here that e. carotovora subspecies possess two classes of quorum-sensing signaling systems defined by the nature of the major ahl analog produced as well as structural and functional characteristics of ahl synthase (ahli) and ahl receptor (expr). class i strains represented by e. carotovora subsp. atroseptica s ... | 2005 | 16291676 |
| conserved role of the linker alpha-helix of the bacterial disulfide isomerase dsbc in the avoidance of misoxidation by dsbb. | in the bacterial periplasm the co-existence of a catalyst of disulfide bond formation (dsba) that is maintained in an oxidized state and of a reduced enzyme that catalyzes the rearrangement of mispaired cysteine residues (dsbc) is important for the folding of proteins containing multiple disulfide bonds. the kinetic partitioning of the dsba/dsbb and dsbc/dsbd pathways partly depends on the ability of dsbb to oxidize dsba at rates >1000 times greater than dsbc. we show that the resistance of dsbc ... | 2006 | 16280324 |
| expression of the hypersensitive response-assisting protein in arabidopsis results in harpin-dependent hypersensitive cell death in response to erwinia carotovora. | active defense mechanisms of plants against pathogens often include a rapid plant cell death known as the hypersensitive cell death (hcd). hypersensitive response-assisting protein (hrap) isolated from sweet pepper intensifies the harpin(pss)-mediated hcd. here we demonstrate that constitutive expression of the hrap gene in arabidopsis results in an enhanced disease resistance towards soft rot pathogen, e. carotovora subsp. carotovora. this resistance was due to the induction of hcd since differ ... | 2005 | 16270229 |
| [review on hrp genes of plant pathogenic bacteria]. | the hrp genes exist in 4 kinds of gram-negative plant pathogenic bacteria and are responsible for the pathogenicity of bacteria. they can induce hypersensitive response on non-host and resistant plants. in the present paper, we summarized the hrp genes clusters, the relationship between hrp and avr genes, harpin proteins encoded by hrp genes, modulation and function of hrp genes, and plant-bacteria interactions mediated by hrp genes in more details. moreover, trends in future research of plant p ... | 2005 | 16257922 |
| potato homologs of arabidopsis thaliana genes functional in defense signaling--identification, genetic mapping, and molecular cloning. | defense against pests and pathogens is a fundamental process controlled by similar molecular mechanisms in all flowering plants. using arabidopsis thaliana as a model, steps of the signal transduction pathways that link pathogen recognition to defense activation have been identified and corresponding genes have been characterized. defense signaling (ds) genes are functional candidates for controlling natural quantitative variation of resistance to plant pathogens. nineteen arabidopsis genes oper ... | 2005 | 16255250 |
| molecular genetics of erwinia amylovora involved in the development of fire blight. | the bacterial plant pathogen, erwinia amylovora, causes the devastating disease known as fire blight in some rosaceous plants like apple, pear, quince, raspberry and several ornamentals. knowledge of the factors affecting the development of fire blight has mushroomed in the last quarter century. on the molecular level, genes encoding a hrp type iii secretion system, genes encoding enzymes involved in synthesis of extracellular polysaccharides and genes facilitating the growth of e. amylovora in ... | 2005 | 16253442 |
| [cloning and characterization of an harpin-encoding gene from xanthomonas axonopodis pv. glycines required for hypersensitive response on nonhost plant tobacco]. | an hpa1 gene was cloned into an expression vector, pet30a(+), from the genomic dna of xanthomonas axonopodis pv. glycines (xag), the causal agent of soybean bacterial pustule, with degenerated primers by polymerase amplification reaction (pcr). the gene product was extracted from the conjugate (bhr-3) of bl21 (des) with the recombined vector phr3 after the engineering strain was induced by iptg in lb medium. the sds-page gel showed that the gene product was 15.1kd. the product was heat-stable (1 ... | 2005 | 16245857 |
| the evolution of microbial phosphonate degradative pathways. | phosphonate utilization by microbes provides a potential source of phosphorus for their growth. homologous genes for both c-p lyase and phosphonatase degradative pathways are distributed in distantly related bacterial species. the phn gene clusters for the c-p lyase pathway show great structural and compositional variation among organisms, but all contain phng-phnm genes that are essential for c-p bond cleavage. in the gamma-proteobacterium erwinia carotovora, genes common to phosphonate biosynt ... | 2005 | 16245012 |
| identification of quorum-sensing signal molecules and the luxri homologs in fish pathogen edwardsiella tarda. | edwardsiella tarda is a gram-negative bacterium that causes septicaemia in fish and serious damage to the aquaculture industry. the virulence factors of this pathogen and control mechanisms of the expression of virulence genes have not yet been clearly elucidated. a number of gram-negative pathogenic bacteria have a quorum-sensing system. these bacteria produce n-acyl-l-homoserine lactone (ahl) that they use them as a quorum-sensing signal molecule. in this study, we found that e. tarda isolated ... | 2004 | 16233705 |
| effect of freeze-thaw repetitions upon the supercooling release ability of ice-nucleating bacteria. | we have studied the durability of ice-nucleating bacteria with a potent supercooling release capacity through repeated freeze-thaw cycles. through experiment, we confirmed that uv sterilized erwinia ananas maintains a superior supercooling release capacity at around -1 degrees c through 2000 freeze-thaw cycles. we also found that gamma-ray sterilization, which is more suitable than uv for large-scale sterilization treatment, has a similar effect at appropriately selected doses. | 2004 | 16233592 |
| purification and properties of an ice-nucleating protein from an ice-nucleating bacterium, pantoea ananatis kuin-3. | an ice-nucleating protein (inp) from the extracellular ice-nucleating matter (eim) of pantoea ananatis (erwinia uredovora) kuin-3 was purified and characterized. the eim produced by the strain kuin-3 was purified by ultrafiltration, sucrose density-gradient ultracentrifugation and gel filtration. the inp was purified using of column chromatography on hydroxyapatite and superdex 200 in the nondenaturing detergent of 0.1% (w/v) triton x-100. the purified inp was composed of one subunit of 117 kda ... | 2003 | 16233385 |
| construction of an effective protein expression system using the tpl promoter in escherichia coli. | an effective protein expression system was constructed in escherichia coli using the promoter of the tyrosine phenol-lyase (tpl) gene of erwinia herbicola. this system involves a mutant form of the tyrr protein with an enhanced ability to activate tpl and the tutb protein with an ability to transport l-tyrosine (an inducer of tpl). the highest expression level obtained for this system was more than twice that obtained for the tac system, although it was lower than the level obtained for the t7 s ... | 2005 | 16215823 |
| biological activities of purified harpin(xoo) and harpin(xoo) detection in transgenic plants using its polyclonal antibody. | many harpins have been found in plant pathogen bacteria that can elicit disease and insect resistance in plants, and promote plant growth. in this work, we overexpressed and purified xanthomonas oryzae pv. oryzae harpin, harpin(xoo), in escherichia coli bl21/pgex-hpa1. harpin(xoo) was fused to the c-terminus of glutathione s-transferase (gst) and purified using the bulk gst purification module and thrombin cleavage capture kit. purified harpin(xoo) protein was sensitive to protease k and stable ... | 2005 | 16215640 |
| tol-pal proteins are critical cell envelope components of erwinia chrysanthemi affecting cell morphology and virulence. | the tol-pal genes are necessary for maintaining the outer-membrane integrity of gram-negative bacteria. these genes were first described in escherichia coli, and more recently in several other species. they are involved in the pathogenesis of e. coli, haemophilus ducreyi, vibrio cholerae and salmonella enterica. the role of the tol-pal genes in bacterial pathogenesis was investigated in the phytopathogenic enterobacterium erwinia chrysanthemi, assuming that this organism might be a good model fo ... | 2005 | 16207916 |
| a rapid radiochemical bacterial bioassay to evaluate copper toxicity in freshwaters. | a rapid, highly sensitive bacterial bioassay to determine copper toxicity in freshwaters was developed based on the inhibition of cellular assimilation of radiolabeled glucose. the test used a copper-sensitive bacterium isolated from a freshwater stream. employing sensitive radiochemical techniques enabled environmentally relevant concentrations of the test bacterium (10(5) cells ml(-1)) and a short incubation period (4 hours) to be used, which minimized the potential for changes in copper speci ... | 2005 | 16205992 |
| 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 |
| towards the identification of type ii secretion signals in a nonacylated variant of pullulanase from klebsiella oxytoca. | pullulanase (pula) from the gram-negative bacterium klebsiella oxytoca is a 116-kda surface-anchored lipoprotein of the isoamylase family that allows growth on branched maltodextrin polymers. pula is specifically secreted via a type ii secretion system. pelbsp-pula, a nonacylated variant of pula made by replacing the lipoprotein signal peptide (sp) with the signal peptide of pectate lyase pelb from erwinia chrysanthemi, was efficiently secreted into the medium. two 80-amino-acid regions of pula, ... | 2005 | 16199575 |
| bacterial species specificity in prou osmoinducibility and nptii and lacz expression. | reporter gene-based transcriptional fusions are increasingly being used to address questions in microbial ecology, with constitutively expressed fusions enabling microbe tracking and inducible fusions reporting the presence of environmental signals. to more readily apply this technology to a variety of bacterial species, we examined species specificity in the expression of three promoters of interest. a comparison of two potentially constitutive promoters, each fused to the reporter gene gfp, sh ... | 2004 | 16179797 |
| antibacterial iminopyrrolidines from burkholderia plantarii, a bacterial pathogen of rice. | burkholderia plantarii, a bacterial pathogen on rice, produced compounds in liquid culture that gave strong inhibitory action against erwinia amylovora, the bacterium responsible for fire blight disease of apple and pear trees. the active component was hydrophilic and ionic, and was fractionated extensively by passage through sp, deae, and lh20 sephadexes. final purification was achieved by reverse phase chromatography on c(18)-bonded silica. biological activity was associated with two compounds ... | 2005 | 16172692 |
| characterization of enterobacteria using maldi-tof mass spectrometry. | a method is proposed for the rapid classification of gram-negative enterobacteria using on-slide solubilization and trypsin digestion of proteins, followed by maldi-tof ms analysis. peptides were identified from tryptic digests using microsequencing by tandem mass spectrometry and database searches. proteins from the outer membrane family (omp) were consistently identified in the enterobacteria escherichia coli, enterobacter cloacae, erwinia herbicola, and salmonella typhimurium. database search ... | 2005 | 16159146 |
| gene stacking in phalaenopsis orchid enhances dual tolerance to pathogen attack. | cymbidium mosaic virus (cymmv) and erwinia carotovora have been reported to cause severe damage to orchid plants. to enhance the resistance of orchids to both viral and bacterial phytopathogens, gene stacking was applied on phalaenopsis orchid by double transformation. plbs originally transformed with cymmv coat protein cdna (cp) were then re-transformed with sweet pepper ferredoxin-like protein cdna (pflp) by agrobacterium tumefaciens, to enable expression of dual (viral and bacterial) disease ... | 2005 | 16145836 |
| the hrpn gene of erwinia amylovora stimulates tobacco growth and enhances resistance to botrytis cinerea. | erwinia amylovora is a member of the harpin proteins that induces pathogen resistance and hypersensitive cell death in plants. to obtain tobacco plants displaying a hypersensitive response, the hrpn gene from erwinia amylovora was cloned into vector pmjc-gb under the control of the rice cytochrome promoter and transfected into tobacco. southern hybridization with a hrpn probe revealed that the gene was present in one copy in the transgenic plants. in addition, hrpn transcripts could be detected ... | 2006 | 16136336 |
| [purification and properties of recombinant erwinia carotovora l-asparaginase expressed in e.coli cells]. | the method of purification erwinia carotovora recombinant l-asparaginase, expressed in e.coli, including ultrasonic disintegration of biomass, fractionation ammonium sulfate and column chromatography on cm- or sp-sepharose has been developed. according to sds-paage the enzyme preparation was homogeneous, its specific activity and yield consist respectively about 620 iu/mg of protein and 75%. physical-chemical and structural properties of recombinant erwinia carotovora l-asparaginase are similar ... | 2003 | 16119104 |
| the family of serratia type pore forming toxins. | the serratia marcescens hemolysin represents the prototype of a growing family of pore forming toxins. the available bacterial genome sequences reveal serratia hemolysin homologues in additional species. however, only s. marcescens hemolysin has been studied in great molecular detail. this family of toxins has nothing in common with the pore forming toxins of e. coli type (rtx toxins), the staphylococcus aureus alpha-toxin or the thiol activated toxin of group a beta-hemolytic streptococci (stre ... | 2005 | 16101433 |
| elevated temperature enhances virulence of erwinia carotovora subsp. carotovora strain ec153 to plants and stimulates production of the quorum sensing signal, n-acyl homoserine lactone, and extracellular proteins. | erwinia carotovora subsp. atroseptica, e. carotovora subsp. betavasculorum, and e. carotovora subsp. carotovora produce high levels of extracellular enzymes, such as pectate lyase (pel), polygalacturonase (peh), cellulase (cel), and protease (prt), and the quorum-sensing signal n-acyl-homoserine lactone (ahl) at 28 degrees c. however, the production of these enzymes and ahl by these bacteria is severely inhibited during growth at elevated temperatures (31.2 degrees c for e. carotovora subsp. atr ... | 2005 | 16085860 |
| acyl-homoserine lactones from erwinia psidii r. ibsbf 435t, a guava phytopathogen (psidium guajava l.). | the phytopathogen erwinia psidii r. ibsbf 435t causes rot in branches, flowers, and fruits of guava (psidium guajava l.), being responsible for crop losses, and has no effective control. it was demonstrated that this strain produces two compounds [s-(-)-n-hexanoyl and n-heptanoyl-homoserine lactone], both belonging to the class of quorum-sensing signaling substances. a protocol using gas chromatography-flame ionization detection with chiral stationary phase is described for the absolute configur ... | 2005 | 16076103 |
| structure-activity relationships of erwinia carotovora quorum sensing signaling molecules. | production of virulence factors and secondary metabolites is regulated in the phytopathogen erwinia carotovora by quorum sensing involving n-acylated homoserine lactone (ahl) signaling molecules. non-hydrolyzable ahl analogues were synthesized and screened in vivo. the biological activity of each compound was correlated with its ability to bind erwinia ahl receptor proteins (luxr homologues) in vitro. there is an excellent correlation between carbapenem production in vivo and in vitro binding to ... | 2005 | 16051488 |
| maximising sensitivity for detecting changes in protein expression: experimental design using minimal cydyes. | dige is a powerful tool for measuring changes in protein expression between samples. here we assess the assumptions of normality and heterogeneity of variance that underlie the univariate statistical tests routinely used to detect proteins with expression changes. furthermore, the technical variance experienced in a multigel experiment is assessed here and found to be reproducible within- and across-sample types. utilising the technical variance measured, a power study is completed for several " ... | 2005 | 16035117 |
| population densities of corn flea beetle (coleoptera: chrysomelidae) and incidence of stewart's wilt in sweet corn. | to quantify populations of the corn flea beetle, chaetocnema pulicaria melsheimer (coleoptera: chrysomelidae), and refine estimates of a threshold for its control to prevent stewart's wilt caused by erwinia stewartii, sequential plantings of 'jubilee' sweet corn were made at 2-wk intervals from april or may through august or september 2001 and 2002 at four locations from southern to northern illinois: simpson, brownstown, champaign, and mendota. densities of c. pulicaria and incidence of stewart ... | 2005 | 16022292 |
| [effects of mitomycin c on the expression and transport of ice-nuclei proteins of erwinia herbicola]. | abstract: in this paper, mitomycin c (mmc) was added to different kinds of medium to study the effects of different cultural conditions on the erwinia herbicola 10025a. for the first time it was confirmed that the expressed activity of the ice-nuclei active protein was different from its transportable manner from the ice nucleation active bacteria (erwinia herbicola 10025a). the findings indicated that mmc could stimulate the sos response,and induce the synthesis of some enzymes and proteins, wh ... | 2005 | 16018268 |
| [the multiple character of mutation of resistance to mitomycin c in erwinia carotovora subsp. carotovora]. | it has been shown that mutants of erwinia carotovora subsp. carotovora (eca) resistant to mitomycin c could be characterized by the change of colonies morphology, sensitivity to bacteriocins, and by the change of pathogeneity. it is supposed that mutations responsible for the stability to mitomycin c touch the synthesis of cell membranes components. in some cases mcr-mutations caused cardinal changes--the loss of prototrophy and synthesis of carotinoid pigment. the mutants obtained in this work ... | 2005 | 16018213 |
| [indicator system for studying the lysogenic development of temperate bacteriophage zf40 erwinia carotovora]. | the indicatory system for studying the lysogenic development of the moderate erwiniophage zf40 has been created on the basis of the data on the efficiency of inoculation, adsorption of phage particles on a cell, and cooperation between different clear-mutants. the use of the indicatory strains rc5297 and 62a-dl. derivatives of erwinia carotovora subsp. carotovora 62a, permitted dividing c-mutants of the phage zf40 into two types which, in their turn, include 4 groups of complementation (cooperat ... | 2005 | 16018206 |
| 'candidatus erwinia dacicola', a coevolved symbiotic bacterium of the olive fly bactrocera oleae (gmelin). | the taxonomic identity of the hereditary prokaryotic symbiont of the olive fly bactrocera oleae (diptera: tephritidae) was investigated. in order to avoid superficial microbial contaminants and loosely associated saprophytic biota, flies were surface-sterilized at the larval stage and reared under aseptic conditions until adult emergence. b. oleae flies originating from different geographical locations and collected at different times of the year were tested. bacterial isolation was undertaken f ... | 2005 | 16014495 |
| development of a strain-specific quantitative method for monitoring pseudomonas fluorescens eps62e, a novel biocontrol agent of fire blight. | pseudomonas fluorescens eps62e has been selected in a screening procedure for its high efficacy controlling erwinia amylovora infections in flowers, immature fruits and young pear plants. we developed two monitoring methods which allowed specific detection and quantification of eps62e by combining classical microbiological techniques with molecular tools. rapd and unspecific-pcr fingerprints were used to differentiate eps62e from other p. fluorescens strains. differential amplified fragments fro ... | 2005 | 16006071 |
| ousb, a broad-specificity abc-type transporter from erwinia chrysanthemi, mediates uptake of glycine betaine and choline with a high affinity. | the ability of erwinia chrysanthemi to cope with environments of elevated osmolality is due in part to the transport and accumulation of osmoprotectants. in this study we have identified a high-affinity glycine betaine and choline transport system in e. chrysanthemi. by using a pool of tn5-b21 ousa mutants, we isolated a mutant that could grow in the presence of a toxic analogue of glycine betaine (benzyl-glycine betaine) at high osmolalities. this mutant was impaired in its ability to transport ... | 2005 | 16000740 |
| siderophore-mediated upregulation of arabidopsis ferritin expression in response to erwinia chrysanthemi infection. | ferritins are multimeric iron storage proteins encoded by a four-member gene family in arabidopsis (atfer1-4). to investigate whether iron sequestration in ferritins is a part of an iron-withholding defense system induced in response to bacterial invasion, we used arabidopsis thaliana as a susceptible host for the pathogenic bacterium erwinia chrysanthemi. in this study, we used a t-dna insertion mutant line to show that the lack of a functional atfer1 gene resulted in an enhanced susceptibility ... | 2005 | 15998312 |
| flavohaemoglobin hmpx from erwinia chrysanthemi confers nitrosative stress tolerance and affects the plant hypersensitive reaction by intercepting nitric oxide produced by the host. | host cells respond to infection by generating nitric oxide (no) as a cytotoxic weapon to facilitate killing of invading microbes. bacterial flavohaemoglobins are well-known scavengers of no and play a crucial role in protecting animal pathogens from nitrosative stress during infection. erwinia chrysanthemi, which causes macerating diseases in a wide variety of plants, possesses a flavohaemoglobin (hmpx) whose function in plant pathogens has remained unclear. here we show that hmpx consumes no an ... | 2005 | 15998309 |
| expr, a luxr homolog of erwinia carotovora subsp. carotovora, activates transcription of rsma, which specifies a global regulatory rna-binding protein. | n-acyl homoserine lactone (ahl) is required by erwinia carotovora subspecies for the expression of various traits, including extracellular enzyme and protein production and pathogenicity. previous studies with e. carotovora subsp. carotovora have shown that ahl deficiency causes the production of high levels of rsma, an rna binding protein that functions as a global negative regulator of extracellular enzymes and proteins and secondary metabolites (rsm, regulator of secondary metabolites). we do ... | 2005 | 15995194 |
| structural studies on the exopolysaccharide from erwinia persicina. | the gram-negative bacterial strain hki 0380 was isolated from biofilms located on palaeolithic rock paintings in the cave of bats in zuheros, southern spain. it was identified as the phytopathogenic erwinia persicina and attracted attention due to the production of considerable quantities of slime. the acidic exopolysaccharide produced by the e. persicina was studied after o-deacylation by sugar and methylation analyses, along with (1)h and (13)c nmr spectroscopy. the following structure of the ... | 2005 | 15992784 |
| [expression of gene aiia carrying the promoter of gene cry3aa in bacillus thuringiensis]. | n-acyl-homoserine lactones (ahls), are widely conserved signal molecules present in quorum-sensing systems of many gram-negative bacteria. ahls molecules mediate the expression of virulence genes of a range of bacterial pathogens. recently, it has been reported that aiia protein, which widely exists in bacillus species, can inactivate the ahls by hydrolyzing the lactone bond of ahls, thus attenuate the diseases caused by the expression of virulence genes of bacterial pathogens. bacillus thuringi ... | 2003 | 15969053 |
| epimerase active domain of pseudomonas aeruginosa algg, a protein that contains a right-handed beta-helix. | the polysaccharide alginate forms a protective capsule for pseudomonas aeruginosa during chronic pulmonary infections. the structure of alginate, a linear polymer of beta1-4-linked o-acetylated d-mannuronate (m) and l-guluronate (g), is important for its activity as a virulence factor. alginate structure is mediated by algg, a periplasmic c-5 mannuronan epimerase. algg also plays a role in protecting alginate from degradation by the periplasmic alginate lyase algl. here, we show that the c-termi ... | 2005 | 15968068 |
| [o2-* burst of tobacco leaves triggered by erwinia carotovora subsp. carotovora inoculation]. | o(-.)(2) production based on chemical method by ecc-treated intact tobacco leaves was observed. it showed a long-lasting one-phase course beginning 1 h and ending 14 h after erwinia carotovora subsp. carotovora (ecc) was inoculated. in ecc-treated leaves, o(-.)(2) production rate of 3 h is 2 times of 1 h, and of 10 h it remains 1.7 times. it decreases rapidly between 10 h and 14 h, at 14 h it falls to the level before inoculation. this is a completely different course from the widely accepted tw ... | 2005 | 15961909 |
| cloning, expression and characterisation of erwinia carotovora l-asparaginase. | bacterial l-asparaginases (e.c. 3.5.1.1) have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia. l-asparaginase from erwinia carotovora ncyc 1526 (era) was cloned and expressed in e. coli. the enzyme was purified to homogeneity by a two-step procedure comprising cation-exchange chromatography and affinity chromatography on immobilised l-asparagine. the enzymatic properties of the recombinant enzyme were investigated and the kinetic parameters (k(m), k(ca ... | 2005 | 15951039 |
| genetic modification of potato against microbial diseases: in vitro and in planta activity of a dermaseptin b1 derivative, msra2. | dermaseptin b1 is a potent cationic antimicrobial peptide found in skin secretions of the arboreal frog phyllomedusa bicolor. a synthetic derivative of dermaseptin b1, msra2 (n-met-dermaseptin b1), elicited strong antimicrobial activities against various phytopathogenic fungi and bacteria in vitro. to assess its potential for plant protection, msra2 was expressed at low levels (1-5 microg/g of fresh tissue) in the transgenic potato (solanum tuberosum l.) cv. desiree. stringent challenges of thes ... | 2005 | 15947906 |
| a cftr chloride channel activator prevents hrpn(ea)-induced cell death in arabidopsis thaliana suspension cells. | erwinia amylovora is a necrogenic bacterium that causes fire blight of the maloideae subfamily of roseacae, such as apple and pear. it provokes necrosis in aerial parts of susceptible host plants and the typical hypersensitive reaction in non-host plants. the secreted harpin, hrpn ea, is able by itself to induce an active cell death in non-host plants. ion flux modulations were shown to be involved early in such processes but very few data are available on the plasma membrane ion channel activit ... | 2005 | 15936204 |
| role of xcpp in the functionality of the pseudomonas aeruginosa secreton. | in gram-negative bacteria, most signal-peptide-dependent exoproteins are secreted via the type ii secretion system (t2ss or secreton). in pseudomonas aeruginosa, t2ss consists of twelve xcp proteins (xcpa and xcpp to xcpz) thought to be organized as a multiproteic complex within the envelope. although well conserved, t2ss are known to be species-specific, namely for distant organisms, and this characteristic was thought to involve xcpp. to check which domain of xcpp could be involved in the spec ... | 2005 | 15936176 |