Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| induction of hydrolytic enzymes in brassica campestris in response to pathovars of xanthomonas campestris. | inoculation of mature leaves of turnip (brassica campestris) with the incompatible xanthomonas campestris pv vitians resulted in the induction of beta-1,3-glucanase and chitinase/lysozyme (chl) activity. no increase in the basal activity of beta-1,3-glucanase was observed after inoculation of leaves with heat- or rifampicin-killed x. c. vitians, escherichia coli, or sterile water. inoculation with the compatible x. campestris pv campestris resulted in a slower induction of glucanase than that se ... | 1990 | 16667441 |
| identification of a pathogenicity locus in xanthomonas campestris pv. vesicatoria. | mutants of a tomato strain of xanthomonas campestris pv. vesicatoria (xcv), causal agent of bacterial spot of tomato and pepper, were produced using the transposon tn5 carried in the suicide plasmid pgs9. one prototrophic mutant, m461, was isolated which caused no visible reaction on tomato or pepper, but maintained the wild-type ability to induce a hypersensitive reaction (hr) on tobacco. this mutant showed similar growth characteristics to the wild-type in culture, but growth in planta was red ... | 1990 | 2177139 |
| a xanthomonas campestris pv. campestris protein similar to catabolite activation factor is involved in regulation of phytopathogenicity. | a dna fragment from xanthomonas campestris pv. campestris that partially restored the carbohydrate fermentation pattern of a cya crp escherichia coli strain was cloned and expressed in e. coli. the nucleotide sequence of this fragment revealed the presence of a 700-base-pair open reading frame that coded for a protein highly similar to the catabolite activation factor (cap) of e. coli (accordingly named clp for cap-like protein). an x. campestris pv. campestris clp mutant was constructed by reve ... | 1990 | 2170330 |
| a plant-inducible gene of xanthomonas campestris pv. campestris encodes an exocellular component required for growth in the host and hypersensitivity on nonhosts. | using tn4431, a transposon that allows transcriptional fusions to a promoterless luciferase (lux) operon, we have isolated a nonpathogenic mutant of xanthomonas campestris pv. campestris, i.e., js111, that does not incite any of the black rot symptoms on all tested cruciferous host plants (j. j. shaw, l. g. settles, and c. i. kado, mol. plant microbe interact. 1:39-45, 1988). in the study reported here, we determined that in contrast to the wild-type strain, js111 is unable to induce a hypersens ... | 1990 | 2168373 |
| construction of lactose-utilizing xanthomonas campestris and production of xanthan gum from whey. | xanthomonas campestris pv. campestris possesses a low level of beta-galactosidase and therefore is not able to grow and produce significant amounts of xanthan gum in a medium containing lactose as the sole carbon source. in this study, a beta-galactosidase expression plasmid was constructed by ligating an x. campestris phage phi lo promoter with pkm005, a cole1 replicon containing escherichia coli laczy genes and the lpp ribosome-binding site. it was then inserted into an incp1 broad-host-range ... | 1990 | 2111116 |
| a multipurpose broad host range cloning vector and its use to characterise an extracellular protease gene of xanthomonas campestris pathovar campestris. | a multipurpose broad host range plasmid, pij3200, was constructed by inserting the polylinker-containing 445 bp pvuii fragment of bluescript m13 into the ecori site of the cosmid plafr1. using this vector a protease gene of xanthomonas campestris pathovar campestris, previously cloned in the recombinant plasmid pij3070, was located by deletion to a 2.2 kb dna region. sequencing of the protease gene revealed an open reading frame encoding a 580 amino acid polypeptide with molecular weight of 57,0 ... | 1990 | 2187155 |
| 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 ... | 1990 | 2259339 |
| extracellular proteases from xanthomonas campestris pv. campestris, the black rot pathogen. | two proteases (prt1 and prt2) were fractionated from culture supernatants of wild-type xanthomonas campestris pv. campestris by cation-exchange chromatography on sp-5pw. inhibitor experiments showed that prt 1 was a serine protease which required calcium ions for activity or stability or both and that prt 2 was a zinc-requiring metalloprotease. prt 1 and prt 2 showed different patterns of degradation of beta-casein. the two proteases comprised almost all of the extracellular proteolytic activity ... | 1990 | 2285313 |
| small, stable shuttle vectors for use in xanthomonas. | plasmids from three broad-host-range (bhr) incompatibility groups (inc) were evaluated for use as cloning vectors in xanthomonas campestris pv. malvacearum (xcm), the causal agent of bacterial blight of cotton. the incp vectors plafr3 and pvk102 could not be introduced into xcm at a significant frequency (less than 1 x 10(-10] and incq vectors such as pkt210 were unstable in their maintenance and tended to delete cloned inserts. incw vectors such as psa747 also were lost readily from xcm in the ... | 1990 | 2341039 |
| cloning and analysis of a 35.3-kilobase dna region involved in exopolysaccharide production by xanthomonas campestris pv. campestris. | cosmid clones able to restore exopolysaccharide production in possibly insertion sequence element-induced surface mutants of xanthomonas campestris pv. campestris were isolated. by fragment-specific tn5-lac mutagenesis of one of the cosmids, pxcb1002, a new dna region which is involved in exopolysaccharide biosynthesis and which is organized into at least 12 complementation groups was identified. | 1990 | 2332409 |
| numerical analysis of 295 phenotypic features of 266 xanthomonas strains and related strains and an improved taxonomy of the genus. | an extensive phenotypic description and an improved classification and nomenclature of the genus xanthomonas are presented. a total of 266 strains obtained from different geographical areas, including representative strains of all species of the genus xanthomonas and most pathovars of xanthomonas campestris, as well as strains which might be genetically related to the genus xanthomonas, were examined for 295 morphological, biochemical, and physiological features. similarities among the strains w ... | 1990 | 2275852 |
| use of oligonucleotide probes to identify members of two-component regulatory systems in xanthomonas campestris pathovar campestris. | two-component regulatory systems comprising a sensor and a regulator protein, both with highly conserved amino acid domains, and commonly genetically linked, have been described in a range of bacterial species and are involved in sensing environmental stimuli. we used two oligonucleotide probes matching the postulated coding regions for domains of sensor and regulator proteins respectively in xanthomonas campestris pathovar campestris (xcc) to identify possible two-component regulatory systems i ... | 1990 | 2233675 |
| a simple method for maintaining xanthomonas campestris pv. citri. | a typical colony of each of strains xw17, xw45, xw47, xw82, xw86, xw118, and xw138 of xanthomonas campestris pv. citri was streaked onto nutrient agar, gy agar, minimal agar, and semi-enriched minimal agar plates, respectively. the agar plates, after incubated at 30 degrees c for 2-4 days, were inverted and stored at 4 degrees c in darkness. all of the x. campestris pv. citri strains retained their viability for at least 26 weeks on the semi-enriched minimal agar plates; whereas, cultures of the ... | 1990 | 2394191 |
| the melanin operon of streptomyces antibioticus: expression and use as a marker in gram-negative bacteria. | the melc operon of streptomyces antibioticus contains two genes, melc1 and melc2, necessary for the production of melanin pigment. we transferred the coding sequence of melc1 and melc2 to escherichia coli plasmid pmtl23 such that its transcription was under the control of the lac promoter and melc1 was translationally fused to the lacz alpha fragment. e. coli cultures containing this plasmid, pif413, produced melanin after overnight incubation on 2yt agar supplemented with 0.1 mm cucl2, 0.36 mm ... | 1990 | 2107124 |
| influence of acetyl and pyruvate substituents on the solution properties of xanthan polysaccharide. | xanthan, an exocellular polysaccharide produced by the plant pathogenic bacterium xanthomonas campestris has been the subject of considerable interest in recent years because of its unusual rheological properties in solution ('weak gel') and consequent range of applications. the polymer consists of a cellulosic backbone with trisaccharide side chains linked to alternate backbone residues; acetyl and pyruvate substituents are carried in variable amounts on these side chains. in this study a serie ... | 1990 | 2078534 |
| 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 ... | 1990 | 2152895 |
| identification and dna sequence of a pathogenicity gene of xanthomonas campestris pv. campestris. | a region of xanthomonas campestris pv. campestris dna containing at least two pathogenicity genes was identified. mutants in one gene were clearly reduced in pathogenicity while mutants in the other were only moderately reduced. both classes of mutants were prototrophic and motile, and had wild-type levels of extracellular enzymes and extracellular polysaccharide. they also grew in vitro and in planta at the same rate as the wild type. experiments involving one of the clear pathogenicity mutants ... | 1990 | 2135951 |
| first isolation of xanthomonas campestris from the blood of a chinese woman. | xanthomonas campestris isolated from the blood of a patient with a fever was first reported. xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. chinese cabbage, etc. human infection due to x. campestris has not been reported so far. the characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. we believe that x. campestris is also one of the opportunistic pathogens, which can infect compromised host. | 1990 | 2118062 |
| distribution of alginate gene sequences in the pseudomonas rrna homology group i-azomonas-azotobacter lineage of superfamily b procaryotes. | chromosomal dna from group i pseudomonas species, azotobacter vinelandii, azomonas macrocytogens, xanthomonas campestris, serpens flexibilis, and three enteric bacteria was screened for sequences homologous to four pseudomonas aeruginosa alginate (alg) genes (alga, pmm, algd, and algr1). all the group i pseudomonas species tested (including alginate producers and nonproducers) contained sequences homologous to all the p. aeruginosa alg genes used as probes, with the exception of p. stutzeri, whi ... | 1990 | 1689562 |
| genetic engineering of polysaccharide structure: production of variants of xanthan gum in xanthomonas campestris. | xanthan gum is an extracellular heteropolysaccharide produced by the bacterium xanthomonas campestris. xanthan has wide commercial application as a viscosifier of aqueous solutions. previously, through genetic engineering, a set of mutants defective in the xanthan biosynthetic pathway has been obtained. certain mutants were shown to synthesize and polymerize structural variants of the xanthan repeating unit and thus produce "variant xanthans". initial studies of solution viscosities of these pol ... | 1990 | 1366611 |
| 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 ... | 1990 | 1367453 |
| widespread distribution and fitness contribution of xanthomonas campestris avirulence gene avrbs2. | disease-resistance genes introduced into cultivated plants are often rendered ineffective by the ability of pathogen populations to overcome host resistance. the bacterial pathogen xanthomonas campestris pathovar vesicatoria causes bacterial spot disease of tomato and pepper, and this pathogen has been shown to overcome disease resistance in pepper (capsicum annuum) by evading the recognition and defence response of the host plant. numerous resistance genes to bacterial spot have been identified ... | 1990 | 2374611 |
| characterization of filamentous bacteriophage phi lf from xanthomonas campestris pv. campestris. | a filamentous phage, phi lf, which specifically infects xanthomonas campestris pv. campestris was isolated. the phage particle measured 1,000 (+/- 200) x 8 nm. it formed turbid plaques of about 1 mm in diameter. during multiplication, the progeny virions extruded into the medium without retarding host cell growth. stocks were stable for 6 months at 4 degrees c and survived treatment at 80 degrees c for 10 min. treatment with chloroform, ethanol or acetone completely destroyed infectivity; ethyl ... | 1990 | 2391505 |
| nucleotide sequence of the engxca gene encoding the major endoglucanase of xanthomonas campestris pv. campestris. | the nucleotide sequence of the gene (engxca) encoding the major extracellular endoglucanase (engxca) of the phytopathogenic bacterium xanthomonas campestris pv. campestris (x. c. campestris) was determined and compared with the n-terminal amino acid (aa) sequence of the purified enzyme. an open reading frame of 1479 bp encoding 493 aa was identified, of which the n-terminal 25 aa represent a potential signal peptide. determination of the exact position of a tn5 insertion within engxca, which did ... | 1990 | 2373365 |
| cloning of genes involved in negative regulation of production of extracellular enzymes and polysaccharide of xanthomonas campestris pathovar campestris. | a recombinant plasmid pij3079 contains dna sequences from xanthomonas campestris pv campestris involved in coordinate negative regulation of production of the extracellular enzymes protease, endoglucanase, amylase and polygalacturonate lyase, and extracellular polysaccharide (eps). wild-type bacteria harbouring pij3079 and therefore carrying extra copies of the gene(s) therein showed reduced enzyme and eps production and reduced aggressiveness to plants. localised tn5 mutagenesis of the correspo ... | 1990 | 1700268 |
| characterization of pxv10a, a copper resistance plasmid in xanthomonas campestris pv. vesicatoria. | the efficacy of copper bactericides for control of xanthomonas campestris pv. vesicatoria in eastern oklahoma tomato fields was evaluated. copper bactericides did not provide adequate control, and copper-resistant (cu) strains of the pathogen were isolated. the cu genes in these strains were located on a large indigenous plasmid designated pxv10a. the host range of pxv10a was investigated; this plasmid was efficiently transferred into 8 of 11 x. campestris pathovars. however, the transfer of pxv ... | 1990 | 16348089 |
| copper resistance gene homologs in pathogenic and saprophytic bacterial species from tomato. | copper-resistant strains of xanthomonas campestris pv. vesicatoria, pseudomonas cichorii, pseudomonas putida, pseudomonas fluorescens, and a yellow pseudomonas sp. were isolated from tomato plants or seeds. in southern hybridizations, dna from each strain showed homology with the copper resistance (cop) operon previously cloned from pseudomonas syringae pv. tomato pt23. homology was associated with plasmid and chromosomal dna in x. compestris pv. vesicatoria, p. putida, and the yellow pseudomona ... | 1990 | 16348118 |
| phenotypic switching affecting chemotaxis, xanthan production, and virulence in xanthomonas campestris. | the chemotaxis towards sucrose and yeast extract of nine strains of xanthomonas campestris representing pathovars campestris, armoraciae, translucens, vesicatoria, and pelargonii was analyzed by using swarm plates. unexpectedly, each of these strains formed small or reduced swarms typical of nonmotile or nonchemotactic bacteria. with time, however, chemotactic cells appeared on the swarm plates as blebs of bacteria. these cells were strongly chemotactic and were concomitantly deficient in exopol ... | 1990 | 16348384 |
| pathovar-specific antigens of xanthomonas campestris pv. begoniae and x. campestris pv. pelargonii detected with monoclonal antibodies. | two monoclonal antibodies specific for lipopolysaccharide antigens of xanthomonas campestris pv. begoniae and pv. pelargonii reacted with all of their respective pathovar strains and not with 130 strains of other xanthomonads or 89 nonxanthomonads tested. these results, as well as previous results, indicate that pathovar-specific monoclonal antibodies were readily generated to strains of x. campestris pathovars that generally infect single hosts. | 1990 | 16348131 |
| quantitative analysis of resistance in cotton to three new isolates of the bacterial blight pathogen. | genetic variability for virulence of the bacterial blight pathogen [xanthomonas campestris pv malvacearum (smith) dye] on cotton (gossypium hirsutum l.) has been shown by the identification of 19 races of the pathogen based on disease reactions of a set of ten host differentials. this study was conducted to determine the inheritance of host resistance to three recently identified isolates of x. campestris pv malvacearum, which are virulent on the entire set of differentials. true leaves of tamco ... | 1990 | 24226445 |
| genomic relatedness of xanthomonas campestris strains causing diseases of citrus. | xanthomonas campestris strains that cause disease in citrus were compared by restriction endonuclease analysis of dna fragments separated by pulsed-field gel electrophoresis and by dna reassociation. strains of x. campestris pv. citrumelo, which cause citrus bacterial spot, were, on average, 88% related to each other by dna reassociation, although these strains exhibited diverse restriction digest patterns. in contrast, strains of x. campestris pv. citri groups a and b, which cause canker a and ... | 1991 | 16348555 |
| xanthomonas campestris contains a cluster of hrp genes related to the larger hrp cluster of pseudomonas solanacearum. | all xanthomonas campestris pathovars tested contain dna which hybridizes to the large hrp gene cluster of pseudomonas solanacearum (c.a. boucher, f. van gijsegem, p.a. barberis, m. arlat, and c. zischek, j. bacteriol. 169:5626-5632, 1987). clones carrying these sequences were isolated from genomic libraries of x. campestris pvs. campestris and vitians. mutagenesis of the corresponding genomic regions of both pathovars gave strains defective in both pathogenicity and hypersensitive response induc ... | 1991 | 1666525 |
| [evaluation of culture media for detecting the starch hydrolysis reaction in pathovars of xanthomonas campestris]. | sixty strains of different pathovars of xanthomonas campestris have been tested for the evaluation of various starch agars and compounds of starch degradation on six media: soluble starch, potato insoluble starch, corn insoluble starch, potato amylopectin, corn amylopectin and potato amylose. the purpose of the present investigation was the selection of the most suitable medium for the visualization of the starch hydrolysis test, presenting this reaction as a distinct character between pathovars ... | 1991 | 1726127 |
| 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) ... | 1991 | 1847347 |
| complete nucleotide sequence of filamentous phage cf1c from xanthomonas campestris pv. citri. | 1991 | 1840658 | |
| [production of xanthan gums]. | xanthomonas campestris was investigated in 70 samples of infected plants in the neighbourhood of luján, province of buenos aires, between february and august, 1990. the production of xanthan gum was determined from 50 strains of xanthomonas campestris, as well as the conversion efficiency of substrate concentration into gum and the number of colony forming units (cfu) of xanthomonas campestris/ml of broth culture. the highest number of strains producing extracellular polysaccharide was obtained ... | 1991 | 1815272 |
| a gene from xanthomonas campestris pv. vesicatoria that determines avirulence in tomato is related to avrbs3. | strains of xanthomonas campestris pv. vesicatoria that were avirulent in tomato leaves but virulent in pepper leaves were identified. a cloned gene, avrbsp, from one of the strains, xv 87-7, converted a virulent strain in tomato to avirulent in tomato. a 1.7-kb subclone containing the avirulence gene cross-hybridized with the avirulence gene, which determines race 1 within the pepper group of strains (avrbs3). however, the two avirulence genes differ in their biological activity. the base sequen ... | 1991 | 1804405 |
| dna probes for detection of copper resistance genes in xanthomonas campestris pv. vesicatoria. | the copper resistance (cur) genes encoded on pxv10a, a 190-kb plasmid in xanthomonas campestris pv. vesicatoria xv10, were isolated on a 44-kb cosmid clone designated pcur1. tn5 mutagenesis of pcur1 indicated that a 4.0-kb region was required for copper resistance. three restriction fragments located within the 4.0-kb region demonstrated high specificity for the cur genes present in x. campestris pv. vesicatoria and will be useful in monitoring the presence of these genes in the environment. | 1991 | 1768118 |
| induction of the alka gene of escherichia coli in gram-negative bacteria. | a broad-host-range plasmid containing a fusion of the alka and lacz genes of escherichia coli was introduced into various aerobic and facultative gram-negative bacteria--33 species belonging to 19 genera--to study the induction of expression of the alka gene by alkylating agents. the bacteria included species of the families enterobacteriaceae, pseudomonadaceae, rhizobiaceae, vibrionaceae, neisseriaceae, rhodospirillaceae, and azotobacteraceae. results obtained show that all bacteria tested, exc ... | 1991 | 1938974 |
| structural characterization of protein secretion genes of the bacterial phytopathogen xanthomonas campestris pathovar campestris: relatedness to secretion systems of other gram-negative bacteria. | the nucleotide sequence was determined of a 5.3 kb region of the xanthomonas campestris pathovar campestris genome carrying a gene cluster encoding protein secretion and pathogenicity functions. a putative promoter sequence and five open reading frames (orf) which may be part of an operon were revealed. the five predicted primary translation products comprise 531, 390, 147, 169 and 138 amino acids with mr values of 58,854, 42,299, 15,548, 18,214 and 15,108 respectively. a sixth, partial orf is a ... | 1991 | 1944223 |
| expression of the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria is not under the control of hrp genes and is independent of plant factors. | the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria pepper race 1 is responsible for the induction of a race-specific hypersensitive reaction in resistant pepper cultivars. a dna region of 3.7 kb, containing several open reading frames and an internal repetitive region, was shown previously to be necessary for avirulence activity (u. bonas, r. e. stall, and b. staskawicz, mol. gen. genet. 218:127-136, 1989). the promoter of avrbs3 was identified by using gene fusions to beta-g ... | 1991 | 1938914 |
| site-specific recombination promoted by a short dna segment of plasmid r1 and by a homologous segment in the terminus region of the escherichia coli chromosome. | a short dna segment located in the kanamycin resistance region of plasmid r1 promotes site-specific recombination and plasmid maintenance. this segment has been reduced to 100 bp and subsequently to 44 bp without losing these properties. it can recombine with a similar segment located in the terminus region of the escherichia coli chromosome. it is proposed that this recombination is responsible for the plasmid maintenance properties of the r1 segment. the chromosomal site has been isolated; it ... | 1991 | 1931823 |
| conservation of xcp genes, involved in the two-step protein secretion process, in different pseudomonas species and other gram-negative bacteria. | the two-step protein secretion pathway in pseudomonas aeruginosa is dependent on the xcp genes. we investigated whether a similar secretion mechanism is present in non-pathogenic pseudomonas spp. and in other gram-negative bacteria. the plant growth stimulating pseudomonas strains p. putida wcs358, p. fluorescens wcs374 and pseudomonas b10 appeared to secrete proteins into the extracellular medium. southern hybridization experiments showed the presence of xcp genes in these strains and also in o ... | 1991 | 1921977 |
| isolation and characterization of insertion sequence elements from gram-negative bacteria by using new broad-host-range, positive selection vectors. | on the basis of an rsf1010-derived broad-host-range vector, three different systems which enable positive detection and isolation of insertion sequence (is) elements from gram-negative bacteria were constructed. vectors psup104-phes, psup104-rpsl, and psup104-sac were used successfully in a number of rhizobium strains and in xanthomonas campestris. more than 20 different is elements were isolated and characterized. the 16 is elements from rhizobium meliloti were further used to characterize vari ... | 1991 | 1847366 |
| expression of the reca gene of escherichia coli in several species of gram-negative bacteria. | a broad host range plasmid containing an operon fusion between the reca and lacz genes of escherichia coli was introduced into various aerobic and facultative gram-negative bacteria-30 species belonging to 20 different genera - to study the expression of the reca gene after dna damage. these included species of the families enterobacteriaceae, pseudomonadaceae. rhizobiaceae, vibrionaceae, neisseriaceae, rhodospirillaceae and azotobacteraceae. results obtained show that all bacteria tested, excep ... | 1991 | 2038310 |
| genetic and molecular analysis of a cluster of rpf genes involved in positive regulation of synthesis of extracellular enzymes and polysaccharide in xanthomonas campestris pathovar campestris. | the cosmid clone pij3020 containing dna from the plant pathogenic bacterium xanthomonas campestris pathovar campestris has previously been shown to complement a non-pathogenic mutant defective in synthesis of extracellular enzymes. the dna cloned in pij3020 was analysed by mutagenesis with tn5 and tn5lac and by nucleotide sequencing. the results indicate that this region of the genome contains a cluster of genes, mutation in any of which results in failure of the enzymes and extracellular polysa ... | 1991 | 1645442 |
| identification of two fructose transport and phosphorylation pathways in xanthomonas campestris pv. campestris. | fructose was shown to be phosphorylated by a specific phosphoenolpyruvate-dependent phosphotransferase system (pts) in xanthomonas campestris pv. campestris. transposon mutagenesis of x. campestris was performed and two mutants affected in growth on fructose were isolated. both mutants were deficient in pts activity. comparison of the rate of uptake and phosphorylation of fructose in the wild-type and in the mutant strains revealed the presence of a second fructose permeation and phosphorylation ... | 1991 | 1650911 |
| use of cloned dna methylase genes to increase the frequency of transfer of foreign genes into xanthomonas campestris pv. malvacearum. | in vitro-packaged cosmid libraries of dna from the bacterium xanthomonas campestris pv. malvacearum were restricted 200- to 1,000-fold when introduced into mcr+ strains of escherichia coli compared with restriction in the mcr- strain hb101. restriction was predominantly associated with the mcrbc+ gene in e. coli. a plasmid (pufr052) encoding the xmai and xmaiii dna methylases was isolated from an x. campestris pv. malvacearum library by a screening procedure utilizing mcr+ and mcr- e. coli strai ... | 1991 | 1655710 |
| fructose catabolism in xanthomonas campestris pv. campestris. sequence of the pts operon, characterization of the fructose-specific enzymes. | in xanthomonas campestris pv. campestris, fructose is transported and phosphorylated into fructose 1-phosphate through a phosphoenolpyruvate-dependent phosphotransferase system. the nucleotide sequence of the frua gene encoding the phosphotransferase system permease specific of fructose (eiifru) was determined. the fructose 1-phosphate produced by the phosphotransferase system is phosphorylated into fructose 1,6-bisphosphate by a 1-phosphofructokinase. this enzyme was characterized and the corre ... | 1991 | 1655739 |
| location and cloning of the ketal pyruvate transferase gene of xanthomonas campestris. | genes required for xanthan polysaccharide synthesis (xps) are clustered in a dna region of 13.5 kb in the chromosome of xanthomonas campestris. plasmid pchc3 containing a 12.4-kb insert of xps genes has been suggested to include a gene involved in the pyruvylation of xanthan gum (n.e. harding, j.m. cleary, d.k. cabañas, i. g. rosen, and k. s. kang, j. bacteriol. 169:2854-2861, 1987). an essential step toward understanding the biosynthesis of xanthan gum and to enable genetic manipulation of xant ... | 1991 | 1657892 |
| environmentally regulated algd promoter is responsive to the camp receptor protein in escherichia coli. | the environmentally activated algd promoter of pseudomonas aeruginosa has been shown to be influenced by dna supercoiling. it is believed that protein-induced bending or looping is required for this activation. we studied the role of escherichia coli camp-crp on algd promoter activation in e. coli and show that a functional crp is required for this activation. we also demonstrate that the algd promoter is sensitive to glucose repression both in e. coli and p. aeruginosa. deletion of a putative c ... | 1991 | 1665196 |
| kinetics and modeling of temperature effects on batch xanthan gum fermentation. | batch fermentation kinetics of xanthan gum production from glucose by xanthomonas campestris at temperatures between 22 degrees c and 35 degrees c were studied to evaluate temperature effects on cell growth and xanthan formation. these batch xanthan fermentations were modeled by the logistic equation for cell growth, the luedeking-piret equation for xanthan production, and a modified luedeking-piret equation for glucose consumption. temperature dependence of the parameters in this model was eval ... | 1991 | 18600645 |
| phytoalexin accumulation in arabidopsis thaliana during the hypersensitive reaction to pseudomonas syringae pv syringae. | inoculation of leaves of arabidopsis thaliana (l.) heynh. with the wheat pathogen, pseudomonas syringae pv syringae, resulted in the expression of the hypersensitive reaction and in phytoalexin accumulation. no phytoalexin accumulation was detected after infiltration of leaves with a mutant of p. s. syringae deficient in the ability to elicit a hypersensitive reaction; with the crucifer pathogen, xanthomonas campestris pv campestris; or with 10 millimolar potassium phosphate buffer (ph 6.9). phy ... | 1992 | 16668792 |
| xanthan production in bubble column and air-lift reactors. | a bubble column (0.05 m(3)) and an air-lift fermentor (1.2 m(3)) were used for the production of the exocellular microbial polysaccharide xanthan with xanthomonas campestris in a synthetic medium. upon oxygen depletion in the liquid, the xanthan production rate dropped sharply and then became a linear function of the oxygen transfer rate. the volumetric mass transfer coefficients for oxygen conformed to the correlation of suh et al. using this correlation in combination with the model for xantha ... | 1992 | 18600890 |
| increase of xanthan production by cloning xps genes into wild-type xanthomonas campestris. | previously, genomic banks of xanthomonas campestris were constructed in escherichia coli, using mobilizable broad-host-range cosmids as the vectors. following conjugal transfer, genes involved in the biosynthesis of xanthan polysaccharide (xps) were cloned by the ability to restore the mucoid phenotype to the non-mucoid mutants. in this study, all clones were transferred into the wild-type strain xc17 to evaluate the effects of the cloned genes on xps production. most clones showed no significan ... | 1992 | 1367903 |
| electrotransformation of xanthomonas campestris by rf dna of filamentous phage phi lf. | conditions were optimized for electrotransformation of xanthomonas campestris pv. campestris by the replicative form (rf) dna of filamentous phase phi lf. early logarithmic cells were washed exhaustively with deionized water and subjected to a pulse at a field strength of 12.5 kv/cm with a 25 microf capacitor and a 400 omega resistor. an efficiency of 5.1 x 10(7) pfu per microgram rf dna was obtained. under the same conditions, the broad host range plasmid plafr1 (21.6 kb) transformed x. campest ... | 1992 | 1367905 |
| effect of parb on plasmid stability and gene expression in xanthomonas campestris. | the stabilization locus parb was subcloned into the broad host range plasmid pap2, which contains the alpha-amylase gene from bacillus subtilis, and introduced into xanthomonas campestris pv campestris and x.c.pv manihotis. analysis of the stability of plasmid pap2 (parb-) and pap23 (parb+) showed that the parb locus decreased significantly the plasmid loss rate mainly by x.c.pv campestris. the lower efficiency of stabilization in x.c.pv manihotis was probably due to the incompatibility system b ... | 1992 | 1368368 |
| genetics of xanthan production in xanthomonas campestris: the xana and xanb genes are involved in udp-glucose and gdp-mannose biosynthesis. | the nucleotide sequence of a 3.4-kb ecori-psti dna fragment of xanthomonas campestris pv. campestris revealed two open reading frames, which were designated xana and xanb. the genes xana and xanb encode proteins of 448 amino acids (molecular weight of 48,919) and 466 amino acids (molecular weight of 50,873), respectively. these genes were identified by analyzing insertion mutants which were known to be involved in xanthan production. specific tests for the activities of enzymes involved in the b ... | 1992 | 1370280 |
| expression of the xanthomonas campestris pv. vesicatoria hrp gene cluster, which determines pathogenicity and hypersensitivity on pepper and tomato, is plant inducible. | the hrp gene cluster from xanthomonas campestris pv. vesicatoria determines functions necessary not only for pathogenicity on the host plants pepper and tomato but also for the elicitation of the hypersensitive reaction on resistant host and nonhost plants. transcriptional orientation and expression of the hrp loci were determined with hrp::tn3-gus fusions. in addition, expression of the hrp loci was studied by rna hybridization experiments. expression of the hrp genes was not detectable after g ... | 1992 | 1370664 |
| amino acid and dna sequences of an extracellular basic protease of dichelobacter nodosus show that it is a member of the subtilisin family of proteases. | a dna fragment encoding an extracellular basic protease (pi approximately 9.5) from dichelobacter nodosus, a gram-negative obligate anaerobe and the causative agent of ovine footrot, has been cloned and expressed in escherichia coli and sequenced. e. coli harbouring a plasmid with a 3-kb dna fragment containing the d. nodosus basic-protease gene exhibited proteolytic activity when tested on skim-milk plates. the sequence of the native basic protease isolated from d. nodosus was also determined b ... | 1992 | 1446666 |
| the rhizobium meliloti pmi gene encodes a new type of phosphomannose isomerase. | interspecific complementation of a xanthomonas campestris pv. campestris phosphomannose isomerase (pmi) mutant was used to isolate a cosmid from a genomic library of rhizobium meliloti 2011 carrying the pmi gene of this strain. subcloning experiments localized the coding region to a 2.0-kb sali-clai fragment. nucleotide sequence analysis of this fragment indicated the presence of two open reading frames (orfs), coding for 18- and 43-kda polypeptides. the analysis of the gene function by gene dis ... | 1992 | 1452036 |
| 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 ... | 1992 | 1472714 |
| hrp genes of pseudomonas solanacearum are homologous to pathogenicity determinants of animal pathogenic bacteria and are conserved among plant pathogenic bacteria. | the majority of bacterial plant diseases are caused by members of three bacterial genera, pseudomonas, xanthomonas, and erwinia. the identification and characterization of mutants that have lost the abilities to provoke disease symptoms on a compatible host and to induce a defensive hypersensitive reaction (hr) on an incompatible host have led to the discovery of clusters of hrp genes (hypersensitive reaction and pathogenicity) in phytopathogenic bacteria from each of these genera. here, we repo ... | 1992 | 1472716 |
| determinants of pathogenicity in xanthomonas campestris pv. vesicatoria are related to proteins involved in secretion in bacterial pathogens of animals. | one of the model systems investigated for studying plant bacterial pathogenesis is xanthomonas campestris pv vesicatoria, the causal agent of bacterial spot disease of pepper and tomato. genes necessary for both basic pathogenicity and the induction of the hypersensitive response in resistant plants (hrp genes) were previously isolated from x. c. pv. vesicatoria and characterized genetically. as a first step toward functional analysis, part of the hrp gene cluster, making up several loci, was se ... | 1992 | 1472717 |
| use of whey for production of exocellular polysaccharide by a mutant strain of xanthomonas campestris. | growth and kinetics of the production of exocellular polysaccharide was studied in a mutant strain of xanthomonas campestris lac+ during cultivation in a submerged culture in a medium containing whey. the maximum production of the polymer was observed at the initial stage of the stationary growth phase of the culture. the mean production yield was about 1.4%. the results were comparable with those obtained during cultivation on a lactose medium. | 1992 | 1505865 |
| molecular cloning, characterization and nucleotide sequence of the gene for secreted alpha-amylase from xanthomonas campestris pv. campestris. | alpha-amylase (1,4-alpha-d-glucan glucanohydrolase, ec 3.2.1.1) of apparent molecular mass 45 kda was secreted by xanthomonas campestris pv. campestris grown in medium containing starch or maltose. we isolated its structural gene from a recombinant lambda library and located it on a 2.7 kb dna fragment. nucleotide sequencing of the fragment revealed a potential orf encoding a protein of 475 amino acid residues, including a potential signal sequence of 35 amino acids. the signal processing site w ... | 1992 | 1527504 |
| bioactive polymers: in vitro and in vivo study of controlled release neomycin. | neomycin is coupled on xanthan-a polysaccharide of microbial biosynthesis produced by xanthomonas campestris-through ionic complexation. the kinetics of neomycin release, in vitro, at ph = 8.2 is studied. a controlled release of neomycin, following a zero order kinetics is observed, regardless of the eluent flow. neomycin complexed on xanthan, administered in a unique daily dose to patients suffering from dysentery in the 100 cases taken in study, has shown a high clinical efficiency as compared ... | 1992 | 1573555 |
| rapid generation of directed and unmarked deletions in xanthomonas. | we have devised a rapid four-step procedure for the generation of directed and unmarked chromosomal deletions in bacteria, based on the use of a novel cloning vector containing the bacillus subtilis sacb gene that encodes levansucrase and confers sucrose sensitivity, which can be used for counter-selection. using this technique, we describe the construction of a 6.5 kb directed and unmarked deletion in a phytopathogenicity region of the chromosome in xanthomonas campestris. this procedure allows ... | 1992 | 1574006 |
| the production of hybridoma cell line secreting monoclonal antibodies against xanthomonas campestris pv. oryzae and its application in the classification of strains. | by the fusion of mouse myeloma cells (sp2/0-ag14) and spleen cells derived from balb/c mice immunized with the preparation of xanthomonas campestris pv. oryzae ks-6-6, os-213, yz-32 and yz-24, we obtained 12 hybridoma cell lines secreting monoclonal antibodies. none of the mcabs cross-reacted with the other varieties of plant pathogenetic and non-pathogenetic bacteria. the mcabs could distinguish three variant serotypes of strains. antibody titers of ascites were about 1:10(3)-1:10(6) when measu ... | 1992 | 1284289 |
| [production of xanthan gum in immobilized cultures of xanthomonas campestris]. | the efficiency of xanthan production through surface processes was evaluated. the best porous material was selected first. thereafter, a comparative study was performed using submerged agitated process vs other without agitation but containing the selected porous material. the culture medium used was white potatoes infusion, buffered with k2hpo4 and supplemented with glucose in diverse concentrations. besides, to evaluate a different type of surface process, three vegetables were valued: ipomaea ... | 1992 | 1298018 |
| use of bioluminescence for detection of genetically engineered microorganisms released into the environment. | the persistence and movement of strain js414 of xanthomonas campestris pv. campestris, which was genetically engineered to bioluminesce, were monitored during a limited field introduction. bioluminescence and traditional dilution plate counts were determined. strain js414 was applied to cabbage plants and surrounding soil by mist inoculation, by wound inoculation, by scattering infested debris among plants, and by incorporating bacteria into the soil. bioluminescent x. campestris pv. campestris ... | 1992 | 1311542 |
| cloning and characterization of pathogenicity genes from xanthomonas campestris pv. glycines. | nonpathogenic mutants of xanthomonas campestris pv. glycines 8ra were generated with n-methyl-n-nitro-n'-nitrosoguanidine to identify and characterize pathogenicity genes of the bacterium. a total of 16 nonpathogenic mutants were isolated from 2,000 colonies. one mutant, np1, was chosen for further study. np1 did not multiply in soybean cotyledons. a genomic library of strain 8ra was constructed in the cosmid plafr3, and the cosmids were tested for complementation in np1. one cosmid clone, pih1, ... | 1992 | 1312532 |
| cloning and characterization of a gene required for the secretion of extracellular enzymes across the outer membrane by xanthomonas campestris pv. campestris. | nonpathogenic mutants of xanthomonas campestris pv. campestris, generated from transposon mutagenesis, accumulated extracellular polygalacturonate lyase, alpha-amylase, and endoglucanase in the periplasm. the transposon tn5 was introduced by a mobilizable, suicidal plasmid, psup2021 or peydg1. genomic banks of wild-type x. campestris pv. campestris, constructed on the broad-host-range, mobilizable cosmid plafr1 or plafr3, were conjugated with one of the mutants, designated xc1708. recombinant pl ... | 1992 | 1313415 |
| dna binding specificity and sequence of xanthomonas campestris catabolite gene activator protein-like protein. | the xanthomonas campestris catabolite gene activator protein-like protein (clp) can substitute for the escherichia coli catabolite gene activator protein (cap) in transcription activation at the lac promoter (v. de crecy-lagard, p. glaser, p. lejeune, o. sismeiro, c. barber, m. daniels, and a. danchin, j. bacteriol. 172:5877-5883, 1990). we show that clp has the same dna binding specificity as cap at positions 5, 6, and 7 of the dna half site. in addition, we show that the amino acids at positio ... | 1992 | 1322886 |
| cloning and characterization of a pectate lyase gene from the soft-rotting bacterium pseudomonas viridiflava. | pseudomonas viridiflava is a soft-rotting pathogen of harvested vegetables that produces an extracellular pectate lyase (pl) responsible for maceration of plant tissue. a pel gene encoding pl was cloned from the genome of strain sj074 and efficiently expressed in escherichia coli. after a series of deletion subclonings and analysis by transposon mutagenesis, the pel gene was located in a 1.2-kb psti-bglii genomic fragment. this fragment appears to contain a promoter at the psti end required for ... | 1992 | 1325218 |
| identification of a family of avirulence genes from xanthomonas oryzae pv. oryzae. | races of xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, interact with cultivars of rice in a gene-for-gene specific manner. multiple dna fragments of various sizes from all strains of x. o. pv. oryzae hybridized with avrbs3, an avirulence gene from xanthomonas campestris pv. vesicatoria, in southern blots; this suggests the presence of several homologs and possibly a gene family. a genomic library of a race 2 strain of x. o. pv. oryzae, which is avirulent on rice cu ... | 1992 | 1335800 |
| a xanthomonas pathogenicity locus is induced by sucrose and sulfur-containing amino acids. | expression of hrp (hypersensitive reaction and pathogenicity) genes from xanthomonas campestris pv vesicatoria is suppressed in complex media but induced in the plant. we examined the effects of macronutrients on transcription of hrp-gusa ([beta]-glucuronidase) fusions by growth of the bacteria in defined medium. modified mm1 minimal medium, supplemented with casamino acids, was able to induce hrpf strongly when sucrose or fructose was added as a carbon source. however, high concentrations of ca ... | 1992 | 12297631 |
| evaluation of the biolog substrate utilization system to identify and assess metabolic variation among strains of xanthomonas campestris pv. citri. | metabolic fingerprints of 148 strains of xanthomonas campestris pv. citri originating from 24 countries and associated with various forms of citrus bacterial canker disease (cbcd) were obtained by using the biolog substrate utilization system. metabolic profiles were used to attempt strain identification. only 6.8% of the studied strains were correctly identified when the commercial microlog 2n data base was used alone. when the data base was supplemented with data from 54 strains of x. campestr ... | 1993 | 16348849 |
| similarity between copper resistance genes from xanthomonas campestris and pseudomonas syringae. | plasmid-borne copper resistance genes from copper-resistant strains of xanthomonas campestris pv. vesicatoria from california, florida, and oklahoma shared structural similarities. a strain of x. campestris pv. campestris also contained plasmid-borne copper resistance genes similar to the resistance genes from x. campestris pv. vesicatoria. furthermore, a region of the copper resistance genes from x. campestris pv. vesicatoria 07882 hybridized with copa, the first gene of the copper resistance o ... | 1993 | 16348942 |
| characterization of xanthomonas campestris pathovars by rrna gene restriction patterns. | genomic dna of 191 strains of the family pseudomonadaceae, including 187 strains of the genus xanthomonas, was cleaved by ecori endonuclease. after hybridization of southern transfer blots with 2-acetylamino-fluorene-labelled escherichia coli 16+23s rrna probe, 27 different patterns were obtained. the strains are clearly distinguishable at the genus, species, and pathovar levels. the variability of the rrna gene restriction patterns was determined for four pathovars of xanthomonas campestris spe ... | 1993 | 16348894 |
| outer membrane proteins and lipopolysaccharides in pathovars of xanthomonas campestris. | variations in the outer membrane proteins (omps) and lipopolysaccharides (lpss) of 54 isolates belonging to 16 different pathovars of xanthomonas campestris were characterized. omp samples prepared by sarcosyl extraction of cell walls and lps samples prepared by proteinase k treatment of sonicated cells were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the presence of 4 m urea. in general, the omp and lps profiles within each pathovar were very similar but different f ... | 1993 | 16349114 |
| identification, expression, and dna sequence of the gdp-mannose biosynthesis genes encoded by the o7 rfb gene cluster of strain vw187 (escherichia coli o7:k1). | the o7-specific lipopolysaccharide (lps) in strains of escherichia coli consists of a repeating unit made of galactose, mannose, rhamnose, 4-acetamido-2,6-dideoxyglucose, and n-acetylglucosamine. we have recently cloned and characterized genetically the o7-specific lps biosynthesis region (rfbeco7) of the e. coli o7:k1 strain vw187 (c. l. marolda, j. welsh, l. dafoe, and m. a. valvano, j. bacteriol. 172:3590-3599, 1990). in this study, we localized the gnd gene encoding gluconate-6-phosphate deh ... | 1993 | 7677991 |
| structure of the o-specific polysaccharide of xanthomonas campestris ncppb 45 lipopolysaccharide. | 1993 | 7682475 | |
| cloning and characterization of the glutamate 1-semialdehyde aminomutase gene from xanthomonas campestris pv. phaseoli. | the gene from xanthomonas campestris pv. phaseoli for glutamate 1-semialdehyde (gsa) aminomutase, which is involved in the c5 pathway for synthesis of delta-aminolevulinic acid (ala), was cloned onto a multicopy plasmid, puc18, by the complementation of an ala-deficient mutant (heml) of escherichia coli. subcloning of deletion fragments from the initial 3.5-kb chromosomal fragment allowed the isolation of a 1.7-kb fragment which could complement the heml mutation. nucleotide sequence analysis of ... | 1993 | 7763385 |
| saturation mutagenesis in escherichia coli of a cloned xanthomonas campestris dna fragment with the lux transposon tn4431 using the delivery plasmid pds1, thermosensitive in replication. | a system allowing transposon mutagenesis of cloned dna fragments in escherichia coli with tn4431, which carries the promotorless luciferase (lux) operon of vibrio fischeri, has been developed. the transposon delivery plasmid, pds1, based on an incf replicon, is thermosensitive in replication and mobilizable to many gram-negative bacteria. we used pds1 for tn4431-saturation mutagenesis of a 10-kb dna fragment of xanthomonas campestris pv. campestris (x.c.c.) in e. coli and showed that the express ... | 1993 | 7764391 |
| sequential assembly and polymerization of the polyprenol-linked pentasaccharide repeating unit of the xanthan polysaccharide in xanthomonas campestris. | lipid-linked intermediates are involved in the synthesis of the exopolysaccharide xanthan produced by the bacterium xanthomonas campestris (l. ielpi, r. o. couso, and m. a. dankert, febs lett. 130:253-256, 1981). in this study, the stepwise assembly of the repeating pentasaccharide unit of xanthan is described. edta-treated x. campestris cells were used as both enzyme preparation and lipid-p acceptor, and udp-glc, gdp-man, and udp-glucuronic acid were used as sugar donors. a linear pentasacchari ... | 1993 | 7683019 |
| a 3.9-kb dna region of xanthomonas campestris pv. campestris that is necessary for lipopolysaccharide production encodes a set of enzymes involved in the synthesis of dtdp-rhamnose. | by mutational analysis it was found that a 3.9-kb smai-xhoii dna fragment of xanthomonas campestris pv. campestris is involved in lipopolysaccharide (lps) biosynthesis. lps samples isolated from different mutants carrying mutations in the 3.9-kb smai-xhoii dna fragment exhibited banding patterns in silver-stained sodium dodecyl sulfate-polyacrylamide gels markedly different from that of the wild-type lps. moreover, comparison of the monosaccharide composition obtained by high-performance anion-e ... | 1993 | 8253667 |
| hrpi of erwinia amylovora functions in secretion of harpin and is a member of a new protein family. | hrpi, a 78-kda protein, functions in the secretion of harpin, a proteinaceous elicitor of the hypersensitive response from erwinia amylovora. the predicted amino acid sequence of hrpi is remarkably similar to that of lcrd of yersinia species, the first member of a recently described protein family. other proteins of the family are mixa from shigella flexneri, inva from salmonella typhimurium, flha from caulobacter crescentus, hrpi from pseudomonas syringae pv. syringae, hrpo from pseudomonas sol ... | 1993 | 8253684 |
| homology between the hrpo protein of pseudomonas solanacearum and bacterial proteins implicated in a signal peptide-independent secretion mechanism. | a region of approximately 22 kb of dna defines the large hrp gene cluster of strain gmi1000 of pseudomonas solanacearum. the majority of mutants that map to this region have lost the ability to induce disease symptoms on tomato plants and are no longer able to elicit a hypersensitive reaction (hr) on tobacco, a non-host plant. in this study we present the complementation analysis and nucleotide sequence of a 4772 bp region of this hrp gene cluster. three complete open reading frames (orfs) are p ... | 1993 | 8316211 |
| molecular cloning and characterization of 13 out genes from erwinia carotovora subspecies carotovora: genes encoding members of a general secretion pathway (gsp) widespread in gram-negative bacteria. | the chemical mutagen ethylmethanesulphonate (ems) has been used to generate mutants of erwinia carotovora subspecies carotovora which are defective in the secretion of pectinases (pel) and cellulases (cel) but unaltered for protease (prt) secretion. such mutants, called out-, still synthesize pel and cel but these enzymes accumulate within the periplasm. cosmid clones carrying wild-type e. carotovora ssp. carotovora dna, identified by their ability to restore the out+ phenotype when transferred ... | 1993 | 8326859 |
| characterization of glutathione transferase from xanthomonas campestris. | a single form of glutathione transferase (xc-gst-4.5) having an isoelectric point at ph 4.5 was resolved from xanthomonas campestris cytosol by affinity chromatography and isoelectric focusing. hplc,n-terminal amino acid sequence, and sds-page analyses indicate that xc-gst-4.5 is composed of two identical subunits, each with a molecular mass of 22 kda. as indicated by its substrate specificity, immunological reactivity, and cd spectra, as well as by its n-terminal amino acid sequence, xc-gst-4.5 ... | 1993 | 8342943 |
| resistance in tomato to xanthomonas campestris pv vesicatoria is determined by alleles of the pepper-specific avirulence gene avrbs3. | bacterial spot disease of tomato and pepper caused by xanthomonas campestris pv vesicatoria is prevented by resistance genes in the plant that match genes for avirulence in the bacterium. based on dna homology to the avirulence gene avrbs3, which induces the resistance response on pepper, we have isolated another avirulence gene from x. c. vesicatoria, designated avrbs3-2. this gene differs in specificity from avrbs3 in inducing the hypersensitive response on tomato but not on pepper. sequence a ... | 1993 | 8479432 |
| genetic and biochemical analysis of salmonella typhimurium flii, a flagellar protein related to the catalytic subunit of the f0f1 atpase and to virulence proteins of mammalian and plant pathogens. | flii is a salmonella typhimurium protein that is needed for flagellar assembly and may be involved in a specialized protein export pathway that proceeds without signal peptide cleavage. flii shows extensive sequence similarity to the catalytic beta subunit of the f0f1 atpase (a. p. volger, m. homma, v. m. irikura, and r. m. macnab, j. bacteriol. 173:3564-3572, 1991). it is even more similar to the spa47 protein of shigella flexneri (m. m. venkatesan, j. m. buysse, and e. v. oaks, j. bacteriol. 1 ... | 1993 | 8491729 |
| efficient transposon mutagenesis of xanthomonas campestris pathovar campestris by high-voltage electroporation. | 1993 | 8386520 | |
| a pleiotropic reduced virulence (rvi-) mutant of erwinia carotovora subspecies atroseptica is defective in flagella assembly proteins that are conserved in plant and animal bacterial pathogens. | erwinia carotovora subsp. atroseptica was mutagenized and assayed for virulence in planta. those mutants which exhibited reduced virulence (rvi-) were assayed for growth rate, auxotrophy and extracellular enzyme secretion and seven mutants were found to be wild type for all of these phenotypes. when screened for other phenotypes, two were found to be non-motile. one mutant was complemented for motility by a heterologous gene library. a 2.7kb xmaiii-clai complementing fragment was sequenced and t ... | 1993 | 8412685 |
| genetic analysis of the rhizobium meliloti exoyfq operon: exoy is homologous to sugar transferases and exoq represents a transmembrane protein. | the nucleotide sequence of a 4.8-kb clai-ecori dna fragment of megaplasmid 2 of rhizobium meliloti rm2011 involved in succinoglucan (eps i) synthesis and nodule infection was determined. four open reading frames (orfs) were identified on this fragment. a mutational analysis revealed that these orfs represent genes that were termed exox, exoy, exof, and exoq. the locations of transposon insertions in these exo genes were determined at the nucleotide level. plasmid integration mutagenesis revealed ... | 1993 | 8439670 |
| pathological and molecular characterizations of alfalfa interactions with compatible and incompatible bacteria, xanthomonas campestris pv. alfalfae and pseudomonas syringae pv. pisi. | we report on the interactions of alfalfa with xanthomonas campestris pv. alfalfae and pseudomonas syringae pv. pisi. a hypersensitive response was observed when leaves were infiltrated with p. s. pv. pisi, which remained strictly limited to the injected zone. the compatible interaction with x. c. pv. alfalfae was characterized by water-soaking symptoms and the spreading of the bacterium into the leaf blade. analyses of transcript accumulation were conducted with cdnas encoding enzymes involved i ... | 1993 | 8274775 |
| gene-for-genes interactions between cotton r genes and xanthomonas campestris pv. malvacearum avr genes. | six plasmid-borne avirulence (avr) genes were previously cloned from strain xcmh of the cotton pathogen, xanthomonas campestris pv. malvacearum. we have now localized all six avr genes on the cloned fragments by subcloning and tn5-gusa insertional mutagenesis. none of these avr genes appeared to exhibit exclusively gene-for-gene patterns of interactions with cotton r genes, and avrb4 was demonstrated to confer avr gene-for-r genes (plural) avirulence to x. c. pv. malvacearum on congenic cotton l ... | 1993 | 8097122 |
| amino acid sequence of extracellular acidic protease v5 of dichelobacter nodosus, the causative organism of ovine footrot. | dichelobacter nodosus, a gram-negative obligate anaerobe and the causative organism of ovine footrot, secretes a family of extracellular serine proteases with pi's in the range of 5.2 to 5.6 and a serine basic protease with a pi of approximately 9.5. the primary structure of acidic protease v5 (pi approximately 5.2) from d. nodosus virulent strain 198 was determined by direct amino acid sequencing. this protease consists of a single polypeptide chain of 347 amino acids, contains two disulfide bo ... | 1993 | 8330022 |
| differential expression of conserved protease genes in crucifer-attacking pathovars of xanthomonas campestris. | strains of xanthomonas campestris pathovars armoraciae and raphani, which cause leaf spotting diseases in brassicas, produce a major extracellular protease in liquid culture which was partially purified. the protease (prt 3) was a zinc-requiring metalloenzyme and was readily distinguishable from the two previously characterized proteases (prt 1 and prt 2) of x. campestris pv. campestris by the pattern of degradation of beta-casein and sensitivity to inhibitors. prt 3 was produced at a low level ... | 1993 | 8285704 |