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a new enzymatic method for the determination of free and conjugated glucuronic acid.a new method is reported for the quantitative determination of glucuronic and galacturonic acid, which is based on spectrophotometric measurement of nadh. the nad-linked oxidation of the uronic acids to the corresponding dicarboxylic acids is measured in the presence of uronic acid dehydrogenase. this enzyme was isolated from pseudomonas syringae. the test is highly specific for glucuronic and galacturonic acid and permits the exact determination of free and conjugated glucuronic acid. this enzy ...1976182902
distribution of ice nucleation-active bacteria on plants in nature.a replica plating method for rapid quantitation of ice nucleation-active (ina) bacteria was developed. leaf washings of plant samples from california, colorado, florida, louisiana, and wisconsin were tested for the presence of ina bacteria. of the 95 plant species sampled, 74 were found to harbor ina bacteria. only the conifers were, as a group, unlikely to harbor ina bacteria. all of the ina bacteria isolated resembled either pseudomonas syringae or erwinia herbicola. sufficient numbers of ina ...1978736541
the effects on temperature on growth in vitro of pseudomonas syringae and and xanthomonas pruni. 1977885818
[cell membrane carbohydrates of pseudomonas syringae]. 1977916910
dna sequence of is91 and identification of the transposase gene.is91 is a 1,830-bp insertion sequence that inserts specifically at the sequence caag or gaac of the target and does not duplicate any sequence upon insertion (23). by transposon mutagenesis, we have identified open reading frame 426 (orf426; bp 454 to 1731) as the putative orf for the transposase. it displays a cysteine-rich, potential metal-binding domain in its n-terminal region. adjacent to orf426, there is an orf (orf121) which precedes and terminally overlaps orf426 by one amino acid. tn173 ...19921310503
phenotypic expression of the pseudomonas syringae pv. syringae 61 hrp/hrm gene cluster in escherichia coli mc4100 requires a functional porin.plants, in general, appear to be able to detect the presence of incompatible pseudomonas syringae strains by a hypothetical cell-cell recognition process to initiate inducible defense mechanisms that contribute to disease resistance. a 25-kb hrp/hrm gene cluster isolated from p. syringae pv. syringae 61(phir11) enables escherichia coli to elicit a hypersensitive response (hr), a plant response generally considered to be a manifestation of recognition and resistance. to identify the nature of the ...19921312527
construction of a tn7-lux system for gene expression studies in gram-negative bacteria.a tn7-lux system was developed for gene expression studies in gram- bacteria. the plasmids constructed, phsk728 and phsk729, have the following features: (1) a promoterless vibrio fischeri lux operon as a reporter system; (2) multiple cloning sites (mcs) ahead of the lux operon, in opposite orientation for the cloning of promoter fragments; (3) a transcriptional terminator ahead of the mcs and translational stop codons in all reading frames before the translational start of the luxc gene; (4) a ...19921333438
broad host-range vector for efficient expression of foreign genes in gram-negative bacteria.a broad host-range expression plasmid was constructed comprising the incq replicon, the reca promoter from escherichia coli and the g10-l ribosome binding site (rbs) derived from bacteriophage t7. the structural genes for porcine somatotropin (pst) and e. coli beta-galactosidase (lacz) were used to monitor gene expression in a diverse collection of gram-negative bacterial hosts: escherichia coli, pseudomonas aeruginosa, pseudomonas syringae, pseudomonas putida, pseudomonas fluorescens, pseudomon ...19911367537
structure of syringotoxin b, a phytotoxin produced by citrus isolates of pseudomonas syringae pv. syringae. 19901368646
the pseudomonas syringae pv. syringae 61 hrph product, an envelope protein required for elicitation of the hypersensitive response in plants.pseudomonas syringae pv. syringae 61 contains a 25-kb cluster of hrp genes that are required for elicitation of the hypersensitive response (hr) in tobacco. tnphoa mutagenesis of cosmid phir11, which contains the hrp cluster, revealed two genes encoding exported or inner-membrane-spanning proteins (h.-c. huang, s. w. hutcheson, and a. collmer, mol. plant-microbe interact. 4:469-476, 1991). the gene in complementation group x, designated hrph, was subcloned on a 3.1-kb sali fragment into pcpp30, ...19921400238
molecular cloning in escherichia coli, expression, and nucleotide sequence of the gene for the ethylene-forming enzyme of pseudomonas syringae pv. phaseolicola pk2.the gene for the ethylene-forming enzyme of pseudomonas syringae pv. phaseolicola pk2 was found to be encoded by an indigenous plasmid, designated ppsp1. the gene for the ethylene-forming enzyme was cloned and expressed in escherichia coli jm109. nucleotide sequence analysis of the clone revealed an open reading frame that encodes 350 amino acids (mol. wt. 39,444). in a comparison with other proteins, the homology score for the entire amino-acid sequence of the ethylene-forming enzyme of pseudom ...19921445325
rapid activation of a novel plant defense gene is strictly dependent on the arabidopsis rpm1 disease resistance locus.we cloned and sequenced cdnas encoded by a novel plant defense gene, eli3, from parsley and arabidopsis thaliana. the predicted product shares no homology to known sequences. eli3 mrna accumulates in a. thaliana leaves in response to challenge with phytopathogenic pseudomonas syringae strains. the timing and magnitude of this response are dictated by the genetics of the plant-pathogen interaction being analyzed. during incompatible interactions, where resistance in the plant genotype col-0 is di ...19921464303
disease development in ethylene-insensitive arabidopsis thaliana infected with virulent and avirulent pseudomonas and xanthomonas pathogens.the plant hormone ethylene has been hypothesized to play roles both in disease resistance and in disease susceptibility. these processes were examined by using isogenic virulent and avirulent bacterial pathogens and mutants of arabidopsis thaliana that were altered in ethylene physiology. ethylene-insensitive ein1 and ein2 mutants of arabidopsis were resistant to pseudomonas syringae pv. tomato made avirulent by the addition of the cloned avirulence genes avrrpt2, avrrpm1, or avrb; this suggests ...19921472714
relationship of total viable and culturable cells in epiphytic populations of pseudomonas syringae.the direct viable count method, used to detect viable but nonculturable bacteria in aquatic systems, was modified to examine epiphytic populations of pseudomonas syringae. viable-population sizes determined from the number of cells that elongated when incubated with yeast extract and nalidixic acid were compared with those determined by the conventional plate count method. the plate count method accurately determined the number of viable cells in epiphytic p. syringae populations in a state of a ...19921476434
evidence that the hrpb gene encodes a positive regulator of pathogenicity genes from pseudomonas solanacearum.the hrp gene cluster of pseudomonas solanacearum gmi1000 strain encodes functions that are essential for pathogenicity on tomato and for the elicitation of the hypersensitive response on tobacco. in this study, we present the nucleotide sequence of one of the hrp genes (hrpb) located at the left-hand end of the cluster and we show that hrpb encodes a positive regulator controlling the expression of hrp genes. hrpb has a coding capacity for a 477-amino-acid polypeptide, which shows significant si ...19921479894
multiple periplasmic catalases in phytopathogenic strains of pseudomonas syringae.phytopathogenic strains of pseudomonas syringae are exposed to plant-produced, detrimental levels of hydrogen peroxide during invasion and colonization of host plant tissue. when p. syringae strains were investigated for their capacity to resist h2o2, they were found to contain 10- to 100-fold-higher levels of total catalase activity than selected strains belonging to nonpathogenic related taxa (pseudomonas fluorescens and pseudomonas putida) or escherichia coli. multiple catalase activities wer ...19921514792
identification of a lysa-like gene required for tabtoxin biosynthesis and pathogenicity in pseudomonas syringae pv. tabaci strain ptbr2.024.pseudomonas syringae pv. tabaci strain ptbr2.024 produces tabtoxin and causes wildfire disease on tobacco and green bean. ptbr7.000, a tn5 mutant of ptbr2.024, does not produce tabtoxin, is nonpathogenic on tobacco, and is prototrophic. a 3-kb fragment from a genomic library of the parent strain ptbr2.024 complemented both mutant phenotypes. this 3-kb fragment contains two open reading frames (orfs), orf1 and orf2, and two truncated orfs, orf3 and orf4. the tn5 insert in ptbr7.000 was mapped to ...19921515668
origin, structure, and regulation of argk, encoding the phaseolotoxin-resistant ornithine carbamoyltransferase in pseudomonas syringae pv. phaseolicola, and functional expression of argk in transgenic tobacco.pseudomonas syringae pv. phaseolicola produces the tripeptide n delta(n'-sulfo-diaminophosphinyl)-ornithylalanyl-homoarginin e (phaseolotoxin), which functions as a chlorosis-inducing toxin in the bean halo blight disease by inhibiting ornithine carbamoyltransferase (oct). the bacterium possesses duplicate oct genes, one of which, argk, encodes a toxin-resistant enzyme (roct) and imparts resistance to phaseolotoxin. we sequenced the argk gene from strain nps3121, defined its promoter region, ana ...19921522066
dna homology between siderophore genes from fluorescent pseudomonads.many species of pseudomonads produce fluorescent siderophores involved in iron uptake. we have investigated the dna homology between the siderophore synthesis genes of an opportunist animal pathogen, pseudomonas aeruginosa, and three plant-associated species pseudomonas syringae, pseudomonas putida and pseudomonas sp. b10. there is extensive homology between the dna from the different species, consistent with the suggestion that the different siderophore synthesis genes have evolved from the sam ...19921532617
the cloned avirulence gene avrpto induces disease resistance in tomato cultivars containing the pto resistance gene.resistance of tomato plants to the bacterial pathogen pseudomonas syringae pv. tomato race 0 is controlled by the locus pto. a bacterial avirulence gene was cloned by constructing a cosmid library from an avirulent p. syringae pv. tomato race, conjugating the recombinants into a strain of p. syringae pv. maculicola virulent on a tomato cultivar containing pto, and screening for those clones that converted the normally virulent phenotype to avirulence. the cloned gene, designated avrpto, reduced ...19921537802
organization and environmental regulation of the pseudomonas syringae pv. syringae 61 hrp cluster.the ability of pseudomonas syringae pv. syringae 61 to elicit the hypersensitive response in nonhost plant species has been linked to a cluster of hrp/hrm genes whose expression appears to be environmentally regulated. to understand the genetic organization of this hrp/hrm gene cluster and its expression during the interaction with nonhost plant species better, we constructed a set of chromosomal hrp-uida fusions in p. syringae pv. syringae 61 by tn5-gusa1 mutagenesis of the cloned hrp/hrm gene ...19921548225
biolistic transformation of prokaryotes: factors that affect biolistic transformation of very small cells.five bacterial species were transformed using particle gun-technology. no pretreatment of cells was necessary. physical conditions (helium pressure, target cell distance and gap distance) and biological conditions (cell growth phase, osmoticum concentration, and cell density) were optimized for biolistic transformation of escherichia coli and these conditions were then used to successfully transform agrobacterium tumefaciens, erwinia amylovora, erwinia stewartii and pseudomonas syringae pv. syri ...19921556553
plant and environmental sensory signals control the expression of hrp genes in pseudomonas syringae pv. phaseolicola.the hrp genes of pseudomonas syringae pv. phaseolicola control the development of primary disease symptoms in bean plants and the elicitation of the hypersensitive response in resistant plants. we examined the expression of the seven operons located in the 22-kb hrp cluster (l. g. rahme, m. n. mindrinos, and n. j. panopoulos, j. bacteriol. 173:575-586, 1991) in planta and in vitro under different physiological and nutritional conditions by using chromosomally located hrp::inaz reporter fusions. ...19921592805
efficacy of burning, tillage, and biocides in controlling bacteria released at field sites and effects on indigenous bacteria and fungi.decontamination treatments of burning and biocide application, alone and in combination with tillage, were evaluated for their ability to reduce populations of bacteria applied to the leaves of plants in field plots. in addition, the effects of these control methods on indigenous leaf and soil bacteria and fungi were assessed. field plots of bush beans (phaseolus vulgaris), sprayed with the bacterium pseudomonas syringae, pseudomonas fluorescens, or erwinia herbicola, received the following trea ...19921599240
evidence for a correlation between auxin production and host plant species among strains of pseudomonas syringae subsp. savastanoi.auxin production by 131 strains of pseudomonas syringae subsp. savastanoi was investigated with the aim of looking for correlations among this characteristic and the origin of the strains, the types of symptoms, and the host plant. most of the p.syringae subsp. savastanoi strains, except those isolated from ash, produced auxin and harbored iaa genes. among ash strains, which were pathogenic only on ash, only 2 out of 33 were found to produce auxin and to harbor iaa genes.19921622252
is801, an insertion sequence element isolated from pseudomonas syringae pathovar phaseolicola.a transposable element, designated is801, was isolated from strain lr781 of pseudomonas syringae pathovar phaseolicola in two independent events using the entrapment plasmid, pucd800. is801 is 1517 base pairs in length and contains open reading frames that potentially encode proteins of 311 and 172 amino acids, as well as smaller proteins. unlike most other prokaryotic transposable elements, is801 lacks terminal repeats. sequence analysis revealed two target pentamers for is801 insertion that di ...19911646375
nolc, a rhizobium fredii gene involved in cultivar-specific nodulation of soybean, shares homology with a heat-shock gene.rhizobium fredii strain usda257 does not nodulate soybean (glycine max (l.) merr.) cultivar mccall. mutant 257dh5, which contains a tn5 insert in the bacterial chromosome, forms nodules on this cultivar, but acetylene-reduction activity is absent. we have sequenced the region corresponding to the site of tn5 insertion in this mutant and find that it lies within a 1176bp open reading frame that we designate nolc. nolc encodes a protein of deduced molecular weight 43564. nucleotide sequences homol ...19911646377
cloning and expression of the tabtoxin biosynthetic region from pseudomonas syringae.pseudomonas syringae br2, a causal agent of bean wildfire, was subjected to tn5 mutagenesis in an effort to isolate mutants unable to produce the beta-lactam antibiotic tabtoxin. three of the tabtoxin-minus (tox-) mutants generated appeared to have physically linked tn5 insertions and retained their resistance to the active toxin form, tabtoxnine-beta-lactam (t beta l). the wild-type dna corresponding to the mutated region was cloned and found to restore the tn5 mutants to toxin production. the ...19911648077
limited host range ti plasmids: recent origin from wide host range ti plasmids and involvement of a novel is element, is868.agrobacterium tumefaciens biotype iii octopine strains have been isolated from grapevine tumors worldwide. they comprise limited and wide host range (lhr and whr) strains that carry related tumor-inducing (ti) plasmids with two t-regions, ta and tb. the whr ta-region resembles the biotype i octopine region, whereas the lhr ta-region is a recent deletion derivative of the whr ta-region, which lacks the iaa genes and part of the ipt gene. sequencing of the ta-region of the ubiquitous lhr strain ab ...19911657255
tagetitoxin inhibits rna synthesis directed by rna polymerases from chloroplasts and escherichia coli.tagetitoxin, a chlorosis-inducing phytotoxin produced by pseudomonas syringae pv. tagetis, inhibits rna synthesis directed by chloroplast rna polymerase. in isolated chloroplasts, tagetitoxin quickly and specifically reduced the incorporation of [3h]uridine into rna. when it was added to transcriptionally active chloroplast protein extracts, the toxin directly inhibited incorporation of [32p]utp into rna. in addition, tagetitoxin inhibited in vitro rna synthesis directed by the rna polymerase fr ...19901688434
construction of a transducing virus from double-stranded rna bacteriophage phi6: establishment of carrier states in host cells.bacteriophage phi 6 contains three double-stranded rna (dsrna) genomic segments. we have constructed a plasmid that contains a cdna copy of the middle (m) segment, with a gene for kanamycin resistance (kan) inserted into the psti site. a transcript of this cdna was incorporated in vitro into procapsids along with natural transcripts of the s and l segments. the procapsids were coated with nucleocapsid surface protein p8 and transfected into pseudomonas syringae pv. phaseolicola. the resulting in ...19921727482
genetic and functional analysis of the basic replicon of pps10, a plasmid specific for pseudomonas isolated from pseudomonas syringae patovar savastanoi.the sequence of a 1823 base-pair region containing the replication functions of pps10, a narrow host-range plasmid isolated from a strain of pseudomonas savastanoi, is reported. the origin of replication, oriv, or pps10 is contained in a 535 base-pair fragment of this sequence that can replicate in the presence of trans-acting function(s) of the plasmid. oriv contains four iterons of 22 base-pairs that are preceded by g+c-rich and a+t-rich regions. a dnaa box located adjacent to the repeats of t ...19921738155
characterization of maize polyamine oxidase.some structural and biochemical characteristics of polyamine oxidase (pao) purified from maize shoots have been examined. the enzyme has only alanine as n-terminal amino acid and its n-terminal sequence shows a significant degree of homology with tryptophan 2-monooxygenase from pseudomonas syringae pv. savastanoi. the ph optimum for the stability of the native enzyme is 5, similar to that of the barley leaf enzyme. calorimetric analysis shows a single two-state transition at ph 6 with tm 49.8 de ...19901366693
[studies of differentiation of pseudomonas morsprunorum wormald and pseudomonas syringae van hall by means of physiological and biochemical methods]. 19751106054
purification and properties of an ethylene-forming enzyme from pseudomonas syringae pv. phaseolicola pk2.a novel ethylene-forming enzyme that catalyses the formation of ethylene from 2-oxoglutarate was purified from a cell-free extract of pseudomonas syringae pv. phaseolicola pk2. it was purified about 2800-fold with an overall yield of 53% to a single band of protein after sds-page. the purified enzyme had a specific activity of 660 nmol ethylene min-1 (mg protein)-1. the molecular mass of the enzyme was approximately 36 kda by gel filtration and 42 kda by sds-page. the isoelectric point and optim ...19911770346
molecular genetics of pseudomonas syringae pathovar pisi: plasmid involvement in cultivar-specific incompatibility.a mutant (pf24) of the race 1 strain, 299a, of pseudomonas syringae pv. pisi has been characterized in terms of its interactions with pea (pisum sativum) cultivars. the mutant showed a changed reaction (avirulence to virulence) with a group of pea cultivars, including cvs. belinda and puget, previously thought to contain resistance genes r1 and r3. avirulence towards cv. puget was restored by transfer of any one of five cosmid clones from a race 3 (strain 870a) gene library to a rifampicin-resis ...19911748876
anaerobic growth and cyanide synthesis of pseudomonas aeruginosa depend on anr, a regulatory gene homologous with fnr of escherichia coli.anaerobic growth of pseudomonas aeruginosa on nitrate or arginine requires the anr gene, which codes for a positive control element (anr) capable of functionally complementing an fnr mutation in escherichia coli. the anr gene was sequenced; it showed 51% identity with the fnr gene at the amino acid sequence level. four cysteine residues known to be essential in the fnr protein are conserved in anr. the anr gene product (deduced mr 27,129) was visualized by the maxicell method and migrated like a ...19911787798
somatic antigens of the pseudomonads: structure of the o-specific polysaccharide chain of pseudomonas syringae pv. tabaci 225 (serogroup viii) lipopolysaccharide. 19911720348
somatic antigens of pseudomonads: structure of the o-specific polysaccharide chain of pseudomonas syringae pv. lachrymans 7591 (serogroup ix) lipopolysaccharide. 19911720347
somatic antigens of pseudomonads: structure of the o-specific polysaccharide chain of pseudomonas syringae pv. syringae (cerasi) 435 lipopolysaccharide. 19911720346
epiphytic populations of pseudomonas syringae on barley.the epiphytic populations of pseudomonas syringae were monitored on 23 barley entries planted in the field in four replications during the summer of 1986, and on six selected entries during the summer of 1987, from the second-leaf stage until senescence. populations were initially low (0-3 log colony-forming units (cfu) per leaf) in all but one entry; they generally increased throughout the season, and at the end they reached 3-7 log cfu/leaf. significant differences among the average epiphytic ...19921521185
two reactions are simultaneously catalyzed by a single enzyme: the arginine-dependent simultaneous formation of two products, ethylene and succinate, from 2-oxoglutarate by an enzyme from pseudomonas syringae.a single enzyme isolated from pseudomonas syringae pv. phaseolicola pk2 simultaneously catalyzed two reactions, namely, the formation of ethylene and succinate from 2-oxoglutarate, at a molar ratio of 2:1. in the main reaction, 2-oxoglutarate was dioxygenated to produce one molecule of ethylene and three molecules of carbon dioxide. in the sub-reaction, both 2-oxoglutarate and l-arginine were mono-oxygenated to yield succinate plus carbon dioxide and l-hydroxyarginine, respectively, the latter b ...19921445291
genetic and transcriptional organization of the hrp cluster of pseudomonas syringae pv. phaseolicola.the hrp cluster of pseudomonas syringae pv. phaseolicola encodes functions that are essential for pathogenicity on bean plants and for the elicitation of the hypersensitive response on resistant plants. the cluster was saturated with insertions of transposon tn3-spice that served both as a mutagen and as a sensitive reporter of the expression of the target regions. the mutations covered a 17.5-kb segment in strain nps3121, in which seven hrp::tn5 insertions had been previously mapped, and region ...19911846144
a series of wide-host-range low-copy-number vectors that allow direct screening for recombinants.a series of controlled expression vectors was constructed based on the wide-host-range plasmid pmmb66eh. some of these new vectors code for the alpha-peptide of beta-galactosidase and allow the direct screening of recombinant clones by inactivation of alpha-complementation. the bla gene was replaced in some plasmids by the cat gene of tn9 coding for chloramphenicol resistance, extending the use into beta-lactam-resistant strains. they all feature either the tac or taclac (tac-lac uv5 in tandem) ...19911847347
phosphatidylinositol, a phospholipid of ice-nucleating bacteria.the nature of the phospholipids of the various bacteria that have ice nucleation activity in supercooled water has been determined. the seven bacteria studied included pseudomonas syringae, erwinia herbicola, three escherichia coli k-12 strains that are phenotypically ice+ because they contain plasmids with different amounts of either p. syringae or e. herbicola cloned dna, and two e. coli k-12 strains without cloned ice gene dna. all five ice+ bacterial strains contained small amounts (0.1 to 1 ...19911848220
plant signal molecules activate the syrb gene, which is required for syringomycin production by pseudomonas syringae pv. syringae.the syrb gene is required for syringomycin production by pseudomonas syringae pv. syringae and full virulence during plant pathogenesis. strain b3ar132 containing a syrb::lacz fusion was used to detect transcriptional activation of the syrb gene in syringomycin minimal medium by plant metabolites with signal activity. among 34 plant phenolic compounds tested, arbutin, phenyl-beta-d-glucopyranoside, and salicin were shown to be strong inducers of syrb, giving rise to approximately 1,200 u of beta ...19911885550
rna polymerases from pseudomonas aeruginosa and pseudomonas syringae respond to escherichia coli activator proteins.the activities of rna polymerases (rnaps) from pseudomonas aeruginosa and pseudomonas syringae were compared with that of escherichia coli rnap. all three enzymes are able to initiate transcription at the trpba promoter of p. aeruginosa and at the coliphage lambda promoters, prm and pre, in response to heterospecific activators (trpi protein, repressor, and cii protein, respectively). however, both pseudomonas polymerases have less stringent requirements for promoter recognition in the absence o ...19911898924
conservation of the gene for outer membrane protein oprf in the family pseudomonadaceae: sequence of the pseudomonas syringae oprf gene.the conservation of the oprf gene for the major outer membrane protein oprf was determined by restriction mapping and southern blot hybridization with the pseudomonas aeruginosa oprf gene as a probe. the restriction map was highly conserved among 16 of the 17 serotype strains and 42 clinical isolates of p. aeruginosa. only the serotype 12 isolate and one clinical isolate showed small differences in restriction pattern. southern probing of psti chromosomal digests of 14 species from the family ps ...19911898935
mode of antibacterial action of dodine (dodecylguanidine monoacetate) in pseudomonas syringae.treatment of pseudomonas syringae cells with 50 microm dodecylguanidine monoacetate (dodine) resulted in the rapid degradation and release of rna and cell lysis. higher concentrations resulted in a progressive decrease in the intensity of these responses, and the appearance of extensive zones of coagulated cytoplasm, indicating that the decrease in rna degradation probably resulted from an inhibition of the rnases, due to protein denaturation. dodine also induced expansion of the outer membrane, ...19921381663
expression of a bacterial phaseolotoxin-resistant ornithyl transcarbamylase in transgenic tobacco confers resistance to pseudomonas syringae pv. phaseolicola.toxins have been shown to be an important virulence component for most pathovars of pseudomonas syringae. here we have examined the role of phaseolotoxin in the virulence mechanism of p. syringae pv. phaseolicola by producing transgenic tobacco plants that express a pathogen-derived toxin-resistant target enzyme. such plants are insensitive to the toxin and less prone to infection by the pathogen.19921368986
components of ice nucleation structures of bacteria.nonprotein components attached to the known protein product of the inaz gene of pseudomonas syringae have been identified and shown to be necessary for the most efficient ice nucleation of supercooled h2o. previous studies have shown that cultures of ina+ bacteria have cells with three major classes of ice-nucleating structures with readily differentiated activities. further, some cells in the culture have nucleating activities intermediate between those of the different classes and presumably h ...19911917876
formation of bacterial membrane ice-nucleating lipoglycoprotein complexes.the preliminary finding that nonprotein additions to the protein product of the ice-nucleating gene of pseudomonas syringae or erwinia herbicola are essential for ice nucleation at the warmest temperatures has led to experiments aimed at identifying possible linkages between the ice protein and the other components. it appears that the protein is coupled to various sugars through n- and o-glycan linkages. mannose residues are apparently bound via an n-glycan bond to the amide nitrogen of one or ...19911917877
production of monoclonal antibodies to pseudomonas syringae pv. phaseolicola and xanthomonas campestris pv. phaseoli.the production of monoclonal antibodies (mabs) to ethylenediamine tetraacetic acid (sodium salt) soluble antigens of pseudomonas syringae pv. phaseolicola and xanthomonas campestris pv. phaseoli (fuscans strain) is described. mabs a6-1 and a6-2 produced to ps. syringae pv. phaseolicola are pathovar specific. although mab xp2 produced to x. campestris pv. phaseoli recognized surface antigens of all strains of this pathovar (including fuscans strains) it cross-reacted specifically with x. campestr ...19901367453
principles and biotechnological applications of bacterial ice nucleation.certain aerobic, gram-negative bacteria, including the epiphytic plant pathogen, pseudomonas syringae, possess a membrane protein that enables them to nucleate crystallization in supercooled water. currently, these ice-nucleating (in) bacteria are being used in snow making and have potential applications in the production and texturing of frozen foods, and as a replacement of silver iodide in cloud seeding. a negative aspect of these in bacteria is frost damage to plant surfaces. thus, of the va ...19911760850
construction of a yeast artificial chromosome library of tomato and identification of cloned segments linked to two disease resistance loci.we have constructed a yeast artificial chromosome (yac) library of tomato for chromosome walking that contains the equivalent of three haploid genomes (22,000 clones). the source of high molecular weight dna was leaf protoplasts from the tomato cultivars vfnt cherry and rio grande-ptor, which together contain loci encoding resistance to six pathogens of tomato. approximately 11,000 yacs have been screened with rflp markers that cosegregate with tm-2a and pto - loci conferring resistance to tobac ...19921351245
sequence domains required for the activity of avirulence genes avrb and avrc from pseudomonas syringae pv. glycinea.avrb and avrc from pseudomonas syringae pv. glycinea share significant amino acid homology but interact with different soybean resistance genes to elicit the hypersensitive defense reaction. recombinant genes constructed between avrb and avrc revealed that the central regions were required for avirulence gene activity but the 5' and 3' termini were interchangeable. recombinants involving the central regions did not yield any detectable avirulence gene activity, and no new avirulence phenotypes w ...19911987121
chromogenic method for rapid isolation of reca-like mutants of gram-negative bacteria.we have devised a rapid and widely applicable color test for detecting reca-like mutants of gram-negative bacteria. the technique depends on decreased expression of an escherichia coli reca-lacz fusion in reca mutants and uses a broad-host-range plasmid to transfer the fusion gene into new species. we describe the isolation of a reca-like mutant of pseudomonas syringae by this technique.19911987131
molecular characterization and expression analysis of the anthranilate synthase gene of pseudomonas syringae subsp. savastanoi.the trpe gene, which encodes the large component of the enzyme anthranilate synthase, was isolated from a pseudomonas syringae subsp. savastanoi (p. savastanoi) cosmid library. cosmids that complemented an escherichia coli trpe mutation contained a gene whose product is 86% homologous at the deduced amino acid level to trpe of pseudomonas aeruginosa and pseudomonas putida. amino acid sequence comparison with other trpe sequences revealed the existence of conserved regions between the procaryotic ...19911987141
pseudomonas syringae pv. phaseolicola genomic clones harboring heterologous dna sequences suppress the same phaseolotoxin-deficient mutants.cosmid cloning and mutagenesis were used to identify genes involved in the production of phaseolotoxin, the chlorosis-inducing phytotoxin of pseudomonas syringae pv. phaseolicola, the causal agent of halo blight of bean (phaseolus vulgaris l.). eight stable clones were isolated from a genomic cosmid library by en masse mating to 10 ethyl methanesulfonate (ems)-induced tox- mutants. in cross-matings, each suppressed all 10 mutants as well as an additional 70 ems-induced tox- mutants (and one uv-i ...19911991709
regulation of tabtoxin production by the lema gene in pseudomonas syringae.pseudomonas syringae pv. coronafaciens, a pathogen of oats, was mutagenized with tn5 to generate mutants defective in tabtoxin production. from a screen of 3,400 kanamycin-resistant transconjugants, seven independent mutants that do not produce tabtoxin (tox-) were isolated. although the tn5 insertions within these seven mutants were linked, they were not located in the previously described tabtoxin biosynthetic region of p. syringae. instead, all of the insertions were within the p. syringae pv ...19921314808
the lema gene required for pathogenicity of pseudomonas syringae pv. syringae on bean is a member of a family of two-component regulators.the lema gene of the plant pathogen pseudomonas syringae pv. syringae is required for disease lesion formation on bean plants. cosmid clones that complemented a lema mutant in trans were isolated previously. the lema gene was localized by subcloning and transposon mutagenesis. the lema region and flanking dna were sequenced, and an open reading frame of 2.7 kb was identified. the nucleotide and predicted amino acid sequences of the lema gene showed sequence similarity to a family of prokaryotic ...19921314807
[an analysis of the molecular forms of the lipopolysaccharide from pseudomonas syringae pv. atrofaciens imv k-1025].water extract and salt-edta extract of pseudomonas syringae, pv. atrofaciens cells were fractionated by ultracentrifugation with following salting out of ultracentrifugal supernatant by ammonium sulphate at 55% saturation (ph 4.5). the composition and distribution of lps molecular forms were studied in the obtained fractions by means of electrophoresis in 10% polyacrylamide gel with 1% sodium dodecylsulphate when staining gels by silver nitrate and cumassi. it is shown that ultracentrifugal supe ...19912067421
[loquat canker: a new disease for argentina].a stem canker disease caused by pseudomonas syringae pv. eriobotryae (takimoto) young, dye y wilkie on loquat (eriobotrya japonica [thumb] lindl) was recorded for the first time in argentina. symptoms of the disease appeared as dry stem cankers which in advanced stages surrounded the stems. similar cankers were noticeable on leaves midribs. seven bacterial strains were isolated from diseased loquats and their identification was based on disease symptoms, pathogenicity and cultural and biochemica ...19902102015
cloning of a large gene cluster involved in erwinia amylovora cfbp1430 virulence.phage mudiipr13 insertional mutagenesis of erwinia amylovora cfbp1430 allowed us to isolate 6900 independent cmr mutants. the frequencies of different auxotrophs in this population indicated that mudiipr13 had inserted randomly in e. amylovora. screening of 3500 cmr mutants on (i) apple calli and (ii) pear and apple seedlings led to the isolation of 19 non-pathogenic prototrophic single mutants, four of which expressed a lacz+ hybrid protein. expression of the fusion proteins was temperature sen ...19902117695
indoleacetic acid operon of pseudomonas syringae subsp. savastanoi: transcription analysis and promoter identification.expression of the indoleacetic acid (iaa) operon, which contributes to the virulence of the phytopathogenic bacterium pseudomonas syringae subsp. savastanoi, was monitored by using broad-host-range lacz reporter gene plasmids. a combination of translational (gene) fusions and transcriptional (operon) fusions of p. syringae subsp. savastanoi sequences to lacz allowed localization of the iaa operon promoter. rna recovered from p. syringae subsp. savastanoi strains was mapped with iaa operon-specif ...19902120185
a gene from pseudomonas syringae pv. glycinea with homology to avirulence gene d from p. s. pv. tomato but devoid of the avirulence phenotype.a gene was cloned from pseudomonas syringae pv. glycinea that hybridized to avirulence gene d (avrd), previously cloned from p. s. pv. tomato. unlike avrd, the hypersensitive response (hr) was not elicited when the p. s. pv. glycinea gene was reintroduced into p. s. pv. glycinea race 4 on a broad host range plasmid and the bacteria were inoculated into soybean leaves. dna sequence data disclosed that the p. s. pv. glycinea homologue of avrd encoded a protein containing 86% identical amino acids ...19902132025
uronic acid dehydrogenase from pseudomonas syringae. purification and properties.1. uronic acid dehydrogenase was purified to homogeneity. after a 338-fold purification a yield of 16% was achieved with a specific activity of 81 mumol nadh formed min-1 mg protein-1. 2. the purity of the enzyme was controlled by disc electrophoresis, sodium dodecylsulfate electrophoresis and ultracentrifugation. 3. a molecular weight of 60 000 was determined by gel chromatography and by ultracentrifugation. 4. the native enzyme is composed of two subunits, their molecular weight being 30 000 a ...19762471
characterization of is476 and its role in bacterial spot disease of tomato and pepper.is476 is an endogenous insertion sequence present in copper-tolerant strains of xanthomonas campestris pv. vesicatoria. sequence analysis has revealed that the element is 1,225 base pairs in length, has 26-base-pair inverted repeats, and causes a 4-base-pair target site duplication upon insertion into the avirulence gene avrbs1. comparison of the full-length sequence with sequences in the national biomedical research foundation and national institutes of health data bases showed that one of the ...19902152895
three separate classes of bacterial ice nucleation structures.studies of the properties of the ice nucleation structure exposed on the surfaces of various bacteria such as pseudomonas syringae, erwinia herbicola, or various strains of ice+ recombinant escherichia coli have shown that there are clearly three major related but chemically distinct types of structures on these cells. first, the ability of ice+ cells to nucleate super-cooled d2o has been examined, and it has been found that this ability (relative to the ability of the same cells to nucleate sup ...19902158972
effect of solute on the nucleation and propagation of ice.using the emulsion technique, we have studied nucleation of ice in aqueous solutions containing silver iodide or pseudomonas syringae. using a differential scanning calorimeter (dsc), we determined characteristic temperatures of nucleation, and also rates of nucleation at selected temperatures. the freezing point depression induced by added solute is linearly related to the lowering of both homogeneous and heterogeneous nucleation temperature. nucleation kinetics depend on a fifth power function ...19911746327
effect of ten antibiotics on the recovery of seed-borne pseudomonas syringae pv syringae of cowpea, vigna unguiculata (l.) walp var. it 825-2246-4.the effect of ten different antibiotics: amoxil, ampicillin, chloramphenicol, cloxacillin, cotrimexazole, erythromycin, nitrofurantoin, penicillin, tetracycline and vibramycin on the recovery of seed-borne pseudomonas syringae pv. syringae and on percentage seed germination of cowpea, vigna unguiculata(l.) walp var. it 825-2246-4 at various temperature regimes: 25 degrees c, 30 degrees c, 35 degrees c and 40 degrees c were investigated using the standard blotter method. seeds were presoaked for ...19911814865
[antigenic polysaccharides of bacteria. 37. structure of the polysaccharide chain of pseudomonas syringae pv.tabaci (serogroup vii) lipopolysaccharide].the structure of the o-specific polysaccharide chain of pseudomonas syringae pv. tabaci strain 223 (serogroup vii) lipopolysaccharide was established on the basis of one- and two-dimensional 1h nmr analysis, 13c nmr analysis and calculation of optical rotation. the structure determined by the non-destructive way was confirmed by acid hydrolysis and methylation. (sequence: see text). o-antigen of the strain studied is similar in structure and serological properties to o-antigens of pseudomonas sy ...19901693273
inhibition by agrobacterium tumefaciens and pseudomonas savastanoi of development of the hypersensitive response elicited by pseudomonas syringae pv. phaseolicola.injection into tobacco leaves of biotype 1 agrobacterium tumefaciens or of pseudomonas savastanoi inhibited the development of a visible hypersensitive response to the subsequent injection at the same site of pseudomonas syringae pv. phaseolicola. this interference with the hypersensitive response was not seen with injection of bacterial growth medium or escherichia coli cells. live a. tumefaciens cells were required for the inhibitory effect. various mutants and strains of a. tumefaciens were e ...19902211508
differential induction of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase genes in arabidopsis thaliana by wounding and pathogenic attack.we have isolated cdnas from two distinct genes encoding 3-deoxy-d-arabino-heptulosonate 7-phosphate (dahp) synthase (ec 4.1.2.15) in arabidopsis thaliana. predicted protein sequences from both genes, dhs1 and dhs2, and a potato dahp synthase gene are highly related, but none shows significant sequence similarity to conserved microbial dahp synthase proteins. despite this structural difference, the dhs1 cdna complements mutations in a yeast strain lacking dahp synthase activity. dhs1 rna levels i ...19911681544
purification, cloning, and primary structure of an enantiomer-selective amidase from brevibacterium sp. strain r312: structural evidence for genetic coupling with nitrile hydratase.an enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from brevibacterium sp. strain r312. oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amda. highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from pseudo ...19902254253
conserved repetition in the ice nucleation gene inax from xanthomonas campestris pv. translucens.the nucleotide sequence was determined for the bacterial ice nucleation gene, inax, from xanthomonas campestris pathovar translucens x56s. comparison of the nucleotide sequence of inax to the previously characterized ice nucleation genes, inaz from pseudomonas syringae s203, inaw from pseudomonas fluorescens ms1650, and icee from erwinia herbicola m1 revealed a 65.8%, 67.8%, and 68.8% homology, respectively. within the internal, repetitive domain of the translated product of inax are 153 consecu ...19902259339
gene-for-gene interactions between pseudomonas syringae pv. phaseolicola and phaseolus.the gene for cultivar-specific avirulence to phaseolus vulgaris cv. tendergreen in races 3 and 4 of pseudomonas syringae pv. phaseolicola was isolated and sequenced. genomic clones from libraries of race 3 in plafr1 and race 4 in plafr3, which altered the phenotype of race 5 from virulent to avirulent in tendergreen, were found to possess a common approximately 15-kb region of dna that contained the determinant of avirulence. subcloning and insertion mutagenesis with tn1000 located an avirulence ...19911666524
survival of bacteria during aerosolization.one form of commercial application of microorganisms, including genetically engineered microorganisms is as an aerosol. to study the effect of aerosol-induced stress on bacterial survival, nonrecombinant spontaneous antibiotic-resistant mutants of four organisms, enterobacter cloacae, erwinia herbicola, klebsiella planticola, and pseudomonas syringae, were sprayed in separate experiments in a greenhouse. samples were collected over a distance of 15 m from the spray site for enumeration. spores o ...19902268156
effect of aerosolization on subsequent bacterial survival.to determine whether aerosolization could impair bacterial survival, pseudomonas syringae and erwinia herbicola were aerosolized in a greenhouse, the aerosol was sampled at various distances from the site of release by using all-glass impingers, and bacterial survival was followed in the impingers for 6 h. bacterial survival subsequent to aerosolization of p. syringae and e. herbicola was not impaired 1 m from the site of release. p. syringae aerosolized at 3 to 15 m from the site of release at ...19902268157
isolation and characterization of the gene from pseudomonas syringae pv. phaseolicola encoding the phaseolotoxin-insensitive ornithine carbamoyltransferase.the gene coding for the phaseolotoxin-insensitive ornithine carbamoyltransferase (octase) from pseudomonas syringae pv. phaseolicola has been cloned and sequenced. the gene has a deduced coding capacity for a polypeptide with a calculated mr of 36,520 daltons. comparison of the amino acid sequence of the octase enzymes encoded by the p. aeruginosa argf and the escherichia coli argi and argf genes with the deduced sequence of the newly identified gene shows that 79 amino acid residues are strictl ...19902274044
construction of a stable shuttle vector for high-frequency transformation in pseudomonas syringae pv. syringae.a cryptic 80.3-kilobase plasmid, posu900, in pseudomonas syringae pv. syringae strain j900 could be cured by treatment with mitomycin without affecting the pathogenicity of j900 on the host, phaseolus vulgaris l. the replication region of posu900 was identified, subcloned, and modified for construction of a high-copy cloning vector. this vector could be transformed into pseudomonas strains with high efficiency (ca. 10(6) transformants per microgram of dna) and was very stable during growth of th ...19902294094
indole-3-acetic acid (iaa) synthesis in the biocontrol strain cha0 of pseudomonas fluorescens: role of tryptophan side chain oxidase.pseudomonas fluorescens strain cha0 is an effective biocontrol agent against soil-borne fungal plant pathogens. in this study, indole-3-acetic acid (iaa) biosynthesis in strain cha0 was investigated. two key enzyme activities were found to be involved: tryptophan side chain oxidase (tso) and tryptophan transaminase. tso was induced in the stationary growth phase. by fractionation of a cell extract of strain cha0 on deae-sepharose, two distinct peaks of constitutive tryptophan transaminase activi ...19911663150
effects of betaine on enumeration of airborne bacteria.the osmoprotectant betaine was incorporated into collection fluid and enumeration medium to determine its effects on the colony-forming abilities of airborne bacteria, which were collected from three separate locations: a wastewater treatment plant, the roof of a laboratory building, and an unobstructed farmland. at all locations, addition of 2 to 5 mm betaine caused a significant increase (from 21.6 to 61.3%) in colonial outgrowth, compared with the growth rate of controls without betaine. the ...19902339884
[the specificity of an immune serum to the exocellular lipopolysaccharide of pseudomonas wieringae].the serum obtained to exocellular lipopolysaccharide (elps) of pseudomonas wieringae selectively agglutinated strains of pathovar of p. syringae and did not agglutinated strains of p. cichorii, p. solanacearum, p. gladioli pv. allicola, p. fluoroviolaceus, strains of nonphytopathogenic pseudomonads as well as bacteria of the genera erwinia, bacillus, xanthomonas, klebsiella. consequently, the antigen determinant common with antigen of the species pseudomonas syringae is present in the compositio ...19902352502
pathovar-specific requirement for the pseudomonas syringae lema gene in disease lesion formation.the lema gene is conserved among strains and pathovars of pseudomonas syringae. in p. syringae pv. syringae b728a, a causal agent of bacterial brown spot disese of bean, the lema gene is required for lesion formation on leaves and pods. using lema-containing dna as a probe, we determined that 80 p. syringae pv. syringae strains isolated from bean leaves could be grouped into seven classes based on restriction fragment length polymorphism. marker exchange mutagenesis showed that the lema gene was ...19921622209
physical and functional characterization of the gene cluster encoding the polyketide phytotoxin coronatine in pseudomonas syringae pv. glycinea.pseudomonas syringae pv. glycinea pg4180 produces the polyketide phytotoxin coronatine. the coronatine synthesis genes in pg4180 were previously shown to reside on a 90-kb plasmid designated p4180a. in the present study, clones containing a 34-kb region of p4180a were saturated with tn5, and 71 unique mutations were recombined into p4180a by marker exchange. the effect of each mutation on coronatine synthesis was determined by analyzing the organic acids produced by the mutants by reverse-phase ...19921548231
bacteriophage phi 6 envelope elucidated by chemical cross-linking, immunodetection, and cryoelectron microscopy.bacteriophage phi 6 is an enveloped dsrna virus which infects the plant pathogenic pseudomonas syringae bacterium. using low dose cryoelectron microscopy we show that the nucleocapsid, spikeless virion, and intact virion have radii of 29, 35, and 43 nm, respectively. thus, the membrane is 6 nm thick and the surface spikes of the receptor binding protein p3 extend 8 nm from the membrane surface. cross-linking, immunological, and complementation evidence suggest that the spikes are formed of multi ...19921519356
characterization of two surface-localized antigenic sites on porin protein f of pseudomonas aeruginosa.a rapid colony immunoblot screening procedure was used to demonstrate the surface localization of porin protein f on bacterial colonies of pseudomonas aeruginosa. by this method, we demonstrated that protein f was accessible to four different specific monoclonal antibodies in a wide variety of both mucoid and nonmucoid p. aeruginosa strains. controls were performed to demonstrate that, using this procedure, only surface-exposed epitopes bound monoclonal antibodies and that nonspecific binding of ...19852408719
aluminium, chromium and manganese detoxification mechanisms in pseudomonas syringae: an x-ray fluorescence study.pseudomonas syringae cultured in a defined citrate medium supplemented with 1 mm aluminium, chromium and manganese, respectively, appeared to elicit disparate biochemical responses. at the stationary phase of growth aluminium was predominantly present as an insoluble residue. although virtually none of this metallic element was detected in the supernatant, the bacterial cells appeared to contain some aluminium. following the initial uptake of chromium the microbe secreted the metal in the supern ...19921501591
functional homologs of the arabidopsis rpm1 disease resistance gene in bean and pea.we showed that a bacterial avirulence (avr) gene function, avrppia1, from the pea pathogen pseudomonas syringae pv pisi, is recognized by some, but not all, genotypes of arabidopsis. thus, an avr gene functionally defined on a crop species is also an avr gene on arabidopsis. the activity of avrppia1 on a series of arabidopsis genotypes is identical to that of the avrrpm1 gene from p.s. pv maculicola previously defined using arabidopsis. the two avr genes are homologous and encode nearly identica ...19921477552
[the immunochemical characteristics of the lipopolysaccharides of pseudomonas syringae (pathovars atrofaciens and phaseolicola) and p. holci (serogroup vi)].lipopolysaccharides (lps) of the representatives of strains of serogroup vi pseudomonas syringae (p. syringae pv. atrofaciens 2399, pv. phaseolicola 120a, 7842 and p. holci 8299) possessing virulence and confinement to the host-plant are characterized by high serological activity in direct and cross reactions of the binary diffusion in agar, immunoelectrophoresis, passive hemagglutination and inhibition of passive hemagglutination. a supernatant and a sediment obtained after ultracentrifugation ...19911779908
identification of pseudomonas syringae pathogens of arabidopsis and a bacterial locus determining avirulence on both arabidopsis and soybean.to develop a model system for molecular genetic analysis of plant-pathogen interactions, we studied the interaction between arabidopsis thaliana and the bacterial pathogen pseudomonas syringae pv tomato (pst). pst strains were found to be virulent or avirulent on specific arabidopsis ecotypes, and single ecotypes were resistant to some pst strains and susceptible to others. in many plant-pathogen interactions, disease resistance is controlled by the simultaneous presence of single plant resistan ...19911824334
induction of the copper resistance operon from pseudomonas syringae.cupric sulfate induced mrna specific to the copper resistance gene cluster previously cloned from pseudomonas syringae pv. tomato pt23. mrna from each of the four genes of this cluster responded in a similar manner to induction over time and with different concentrations of cupric sulfate. promoter fusion constructs indicated the presence of a single copper-inducible promoter upstream from the first open reading frame.19882457580
induction of arabidopsis defense genes by virulent and avirulent pseudomonas syringae strains and by a cloned avirulence gene.we developed a model system to study the signal transduction pathways leading to the activation of arabidopsis thaliana genes involved in the defense against pathogen attack. here we describe the identification and characterization of virulent and avirulent pseudomonas syringae strains that elicit disease or resistance symptoms when infiltrated into arabidopsis leaves. the virulent and avirulent strains were characterized by determining growth of the pathogen in arabidopsis leaves and by measuri ...19911824335
the consensus sequence of ice nucleation proteins from erwinia herbicola, pseudomonas fluorescens and pseudomonas syringae.the consensus sequence of three bacterial ice nucleation proteins was determined by extrapolation from the nucleotide (nt) sequences of three ice nucleation-encoding genes, icee (presented here), inaw and inaz. the three proteins possess considerable similarity, so that a preferred amino acid is shown in most positions of the consensus. the corresponding genes show considerable divergence in the third nt positions of synonymous codons, suggesting that the proteins' conserved features have been m ...19892515997
localization of ice nucleation activity and the icec gene product in pseudomonas syringae and escherichia coli.ice nucleation activity and the icec gene product were quantified in different subcellular fractions of the pseudomonas syringae source strain and in escherichia coli containing the cloned icec gene to determine the activity of this protein in different subcellular locations. ice nuclei were nearly completely retained during isolation of cell envelopes but exhibited a decrease in the temperature at which they were expressed. ice nucleation activity was found in triton x-100 insoluble membrane fr ...19892520825
plasmid-mediated production of the phytotoxin coronatine in pseudomonas syringae pv. tomato.pseudomonas syringae pv. tomato pt23.2 produces the chlorosis-inducing phytotoxin coronatine. thirty-eight chlorosis-defective mutants of pt23.2 were previously generated by using the transposon tn5. five mutants contained tn5 insertions in the indigenous plasmid ppt23a; the remaining 33 mutants either were missing ppt23a (29 mutants) or contained deletions in this plasmid (4 mutants). these results suggested that ppt23a was involved in coronatine production in strain pt23.2. this plasmid was in ...19892536682
the induction of manganese superoxide dismutase in response to stress in nicotiana plumbaginifolia.superoxide dismutases (sods) are metalloproteins that catalyse the dismutation of superoxide radicals to oxygen and hydrogen peroxide. the enzyme has been found in all aerobic organisms examined, where it plays a major role in the defence against toxic reduced oxygen species which are generated in many biological oxidations. here we report the complete primary structure of a plant manganese superoxide dismutase (mnsod), deduced from a cdna clone of nicotiana plumbaginifolia. the plant protein is ...19892540959
an ice nucleation reporter gene system: identification of inducible pathogenicity genes in pseudomonas syringae pv. phaseolicola.we have constructed derivatives of the transposon tn3 that allow an ice nucleation gene (inaz) to be used as 'reporter' of the transcriptional activity of genes into which it is inserted. in these derivatives (tn3-ice and tn3-spice), the laczya sequences of transposon tn3-hoho1 were replaced with inaz lacking its native promoter. the ice nucleation activity of virb::inaz fusions in the correct transcriptional orientation was inducible by acetosyringone, a plant metabolite which activates the vir ...19892548841
phaseolotoxin production by pseudomonas syringae pv. phaseolicola: the influence of temperature.phaseolotoxin (n-sulphodiaminophosphinyl-ornithyl-alanyl-homoarginine) is a phytotoxic secondary metabolite produced by pseudomonas syringae pv. phaseolicola. the production of the phytotoxin is strongly regulated by temperature. the optimal temperature for phaseolotoxin production is 18 degrees c. temperatures in the range between 18 degrees c and 30 degrees c inhibit the production of phaseolotoxin in an increasing manner. by temperature shift experiments and the inhibition of protein synthesi ...19892600779
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