| bacteriolysis by immobilized enzymes. | bacteriolytic enzymes produced by achromobacter lunatus were immobilized in collagen membrane. intact bacteria such as pseudomonas solanacearum, xanthomonas oryzae, staphylococcus aureus, and pseudomonas aeruginosa were lyzed with the bacteriolytic enzyme-collagen membrane. relative activity of the bacteriolytic enzyme-collagen membrane against pseu. solanacearum was about 2% of that of native bacteriolytic enzymes. no difference in the optimum ph was observed between immobilized enzymes and nat ... | 1977 | 14747 |
| characterization of deoxycytidylate methyltransferase in xanthomonas oryzae infected with bacteriophage xp12. | three methods, chromatographic, spectrophotometric and tritium-release assay, were used and compared for the assay of deoxycytidylate methyltransferase. all three methods can be used for assay of this enzyme but the tritium-release assay appears to be the most simple and convenient. with the help of this assay the deoxycytidylate methyltransferase has been isolated and purified from sonically disrupted cells of xp12-infected xanthomonas oryzae. using a procedure that involves fractionation with ... | 1978 | 27354 |
| changes in macromolecular synthesis in xanthomonas oryzae infected with bacteriophage xp-12. | phage xp-12, which has complete substitution of the cytosine residues in its dna with 5-methylcytosine residues, was shown to inhibit incorporation of uracil into host dna and rna during the latent period. this apparent inhibition of host macromolecular synthesis was not accompanied by extensive degradation of the host chromosome. phage dna synthesis in infected cells occurred at a faster rate than host dna synthesis in analogous uninfected cells. however, phage dna synthesis could not be accura ... | 1977 | 894790 |
| enzymatic synthesis of deoxy-5-methyl-cytidylic acid replacing deoxycytidylic acid in xanthomonas oryzae phage xp12dna. | | 1976 | 980110 |
| herbicidins a and b, two new antibiotics with herbicidal activity. i. producing organism and biological activities. | herbicidins a and b, two new antibiotics with selective and contact herbicidal activity, were produced by a new species of streptomyces designated as s. sagononensis. among tested microorganisms, herbicidins indicated some activity against fungi in vitro and xanthomonas oryzae in vivo. their characteristic features were brought into relief by their selective and contact killing effect on many dicotyledonous plant as well as their inhibition of germination of the plant seeds, such as chinese cabb ... | 1976 | 993127 |
| nadh oxidase in xanthomonas oryzae and effect of streptomycin and metal ions. | | 1975 | 1205481 |
| 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 |
| assessment of genetic diversity and population structure of xanthomonas oryzae pv. oryzae with a repetitive dna element. | a repetitive dna element cloned from xanthomonas oryzae pv. oryzae was used to assess the population structure and genetic diversity of 98 strains of x. oryzae pv. oryzae collected between 1972 and 1988 from the philippine islands. genomic dna from x. oryzae pv. oryzae was digested with ecori and analyzed for restriction fragment length polymorphisms (rflps) with repetitive dna element as a probe. twenty-seven rflp types were identified; there was no overlap of rflp types among the six races fro ... | 1992 | 1353345 |
| genetic and physical analysis of the rice bacterial blight disease resistance locus, xa21. | nearly isogenic lines (nils) of rice (oryza sativa) differing at a locus conferring resistance to the pathogen xanthomonas oryzae pv. oryzae were surveyed with 123 dna markers and 985 random primers using restriction fragment length plymorphism (rflp) and random amplified polymorphic dna (rapd) analysis. one chromosome 11 marker (rg103) detected polymorphism between the nils that cosegregated with xa21. all other chromosome 11 dna markers tested were monomorphic between the nils, localizing the ... | 1992 | 1362973 |
| 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 |
| the accessibility of 5-methylcytosine to specific antibodies in double-stranded dna of xanthomonas phage xp12. | antibodies specifically directed to 5-methylcytidine were raised in rabbits and purified by affinity chromatography. the accessibility of 5-methyldeoxycytidine (m5dcyd) to such antibodies was studied with dnas from various origins. the reaction was followed by measuring the retention of radiolabelled dna by antibodies on nitrocellulose filters, by immunoprecipitation, by gel filtration and was visualized with the electron microscope. antibodies did not bind to escherichia coli b dna, which is de ... | 1985 | 2412815 |
| cloning and regulation of erwinia herbicola pigment genes. | the genes coding for yellow pigment production in erwinia herbicola eho10 (atcc 39368) were cloned and localized to a 12.4-kilobase (kb) chromosomal fragment. a 2.3-kb avai deletion in the cloned fragment resulted in the production of a pink-yellow pigment, a possible precursor of the yellow pigment. production of yellow pigment in both e. herbicola eho10 and pigmented escherichia coli clones was inhibited by glucose. when the pigment genes were transformed into a cya (adenylate cyclase) e. coli ... | 1986 | 3023282 |
| partial purification and characterization of an inactive precursor of pseudomonas aeruginosa elastase. | an inactive precursor of the extracellular elastase of pseudomonas aeruginosa was extensively purified by immunoadsorption chromatography of the soluble bacterial cell fraction on a column of sepharose coupled to antielastase antibodies. sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified precursor fraction revealed two major protein bands with molecular weights of about 36,000 (p36) and 20,000 (p20) that in the absence of sodium dodecyl sulfate were associated with each ot ... | 1988 | 3125153 |
| interrelationship between colony type, phage susceptibility and virulence in xanthomonas oryzae. | | 1972 | 5084422 |
| amino acid analysis of the coat protein of the filamentous bacterial virus xf from xanthomonas oryzae. | | 1971 | 5112415 |
| the mechanism of aristeromycin. i. growth inhibition of xanthomonas oryzae by aristeromycin. | | 1971 | 5140522 |
| a filamentous bacteriophage from xanthomonas oryzae. | | 1969 | 5358081 |
| biochemical effects of formycin b on xanthomonas oryzae. | | 1968 | 5671990 |
| phage xp12 of xanthomonas oryzae (uyeda et ishiyama) dowson. | | 1968 | 5681525 |
| 5-methylcytosine replacing cytosine in the deoxyribonucleic acid of a bacteriophage for xanthomonas oryzae. | | 1968 | 5760463 |
| phenazines as disinfectants against bacterial leaf blight of the rice plant. | a series of phenazine compounds, including 15 synthetics and a natural derivative, iodinin, were tested for inhibition of selected phytopathogenic bacteria and fungi. eleven of the compounds had bacteriostatic activity for xanthomonas oryzae. three other species of xanthomonas were resistant. phenazine 5-oxide was the most effective phenazine against the bacterial leaf blight. | 1966 | 5970820 |
| a virulent strain of xanthomonas oryzae isolated from rice seeds in india. | | 1967 | 6077705 |
| two sequence-specific endonucleases from xanthomonas oryzae. characterization and unusual properties. | xori and xorii, two sequence-specific endonucleases, have been partially purified from xanthomas oryzae. xori and xorii were shown to be isoschizomers of psti and puvi, respectively. x. oryzae is a particularly good source of this pvui isoschizomer because of the high yield of xorii, its simple purification scheme, and its relative stability. furthermore, xorii was shown to cleave at different positions in its recognition sequence than do at least two of its known isochizomers; xorii cleaves bet ... | 1980 | 6243986 |
| bacteriophage xp-12-induced exonuclease which preferentially hydrolyzes nicked dna. | an exonuclease has been partially purified from xp-12-infected xanthomonas oryzae which is not found in uninfected x. oryzae. although both the phage-induced exonuclease and the major host exonucleolytic dnase released 5'-mononucleotides, these enzymes differed in their chromatographic behavior, ph optimum, salt inhibition, and heat sensitivity. these two exonucleases preferred different substrates. nicked native dna was the best substrate for the phage-induced enzyme, whereas denatured dna was ... | 1980 | 6251244 |
| partial purification and characterization of an exonuclease from xanthomonas oryzae. | an exonuclease with a strong preference for single-stranded deoxyribonucleic acid over double-stranded deoxyribonucleic acid has been purified 500-fold from xanthomonas oryzae. this enzyme liberates 5'-mononucleotides in a reaction which requires mg2+. | 1980 | 6252197 |
| preparation and partial characterization of xanthomonas oryzae phytotoxin. | a synthetic medium containing ammonium nitrate, urea, d-glucose, glycerol, and sodium glutamate was developed for growth of xanthomonas oryzae and preparation of its phytotoxin. culture filtrates and partially purified toxin preparations caused blight symptoms when inoculated in leaves of 30 days old rice plant cv. t(n)1. toxin elicited quicker response than living cells. this activity was due to a non-dialysable, partial acid and heat labile glycopeptide. there was a sharp decrease in activity ... | 1983 | 6613167 |
| release of alkaline phosphatase from cells of xanthomonas oryzae by manipulation of surface permeability. | xanthomonas oryzae was shown to contain a constitutive alkaline phosphatase (ec 3.1.3.1.). the enzyme was detectable in intact cells and releasable by osmotic shock or spheroplast formation indicating its periplasmic location in the cell. sonication released about 85% of the total enzyme, and the releasable amount was increased to 97% when lysozyme was added to the sonicated cells prior to centrifugation. these changes suggest an association of the enzyme with peptidoglycan; the enzyme is not re ... | 1981 | 6793331 |
| a bacteriophage-induced 5-methyldeoxycytidine 5'-monophosphate kinase. | bacteriophage xp-12-infected xanthomonas oryzae have been found to be a source of a kinase preparation which converts m5dcmp to m5dcdp and then to m5dctp using atp as the phosphate donor. optimal formation of the triphosphate required the presence of creatine phosphate and creatine kinase. in the presence of dgtp, dttp and datp, escherichia coli dna polymerase i and t4 dna polymerase catalyzed the incorporation of m5dctp into dna just as efficiently as that of dctp. neither dtmp nor dcmp served ... | 1982 | 7082669 |
| 5-methyl-dctp deaminase induced by bacteriophage xp-12. | bacteriophage xp-12, whose dna contains 34 mol% 5-methylcytosine, induces the synthesis of a unique enzyme, 5-methyl-dctp deaminase. the substrate for this enzyme, 5-methyl-dctp, is produced by reactions catalyzed in part by other phage-induced enzymes, and the product of the reaction is dttp. the deaminase therefore provides a novel pathway for biosynthesis of thymine residues for phage xp-12 dna. evidence is presented that this pathway is used for dttp synthesis in xp-12-infected xanthomonas o ... | 1982 | 7086962 |
| a new thymidylate biosynthesis in xanthomonas oryzae infected by phage xp 12. | | 1982 | 7090182 |
| studies on terreic acid. | it was found that aspergillus sp. no. y-8980 which was isolated from a soil sample collected at yoron island in kagoshima prefecture belonged to aspergillus terreus group by morphological observation. the active substance produced by the strain was obtained with a high yield in sucrose-yeast extract medium and extracted by chloroform, ethyl acetate and n-butanol at ph 2.4 approximately 2.6 from the culture broth. the substance was crystallized from chloroform and ethyl acetate after charcoal tre ... | 1980 | 7190624 |
| mode of action of synephrine on xanthomonas oryzae. | | 1980 | 7399620 |
| a homolog of an escherichia coli phosphate-binding protein gene from xanthomonas oryzae pv. oryzae. | a xanthomonas oryzae pv. oryzae gene with sequence similarity to an escherichia coli phosphate-binding protein gene (phos) produces a periplasmic protein of apparent m(r) 35,000 when expressed in e. coli. amino terminal sequencing revealed that a signal peptide is removed during transport to the periplasm in e. coli. | 1995 | 7579584 |
| rice cationic peroxidase accumulates in xylem vessels during incompatible interactions with xanthomonas oryzae pv oryzae. | a cationic peroxidase, po-c1 (molecular mass 42 kd, isoelectric point 8.6), which is induced in incompatible interactions between the vascular pathogen xanthomonas oryzae pv oryzae and rice (oryza sativa l.), was purified. amino acid sequences from chemically cleaved fragments of po-c1 exhibited a high percentage of identity with deduced sequences of peroxidases from rice, barley, and wheat. polyclonal antibodies were raised to an 11-amino acid oligopeptide (poc1a) that was derived from a domain ... | 1995 | 7770527 |
| avrxa10 protein is in the cytoplasm of xanthomonas oryzae pv. oryzae. | avrxa10 from xanthomonas oryzae pv. oryzae was tagged with a unique hydrophilic octapeptide (flag) to permit antibody-mediated identification and purification of the gene product. x. o. pv. oryzae that produced tagged avrxa10 elicited a hypersensitive response (hr) on rice cultivars containing the resistance gene xa-10, but not on cultivars lacking xa-10. the tagged avrxa10 protein purified from escherichia coli or x. o. pv. oryzae did not elicit a hypersensitive response in rice with the xa-10 ... | 1994 | 7873783 |
| replicon typing of plasmids of phytopathogenic xanthomonads. | replicon types of plasmids of phytopathogenic xanthomonads have been identified. plasmids of xanthomonas oryzae pathovar oryzae belonged to types repp, repw, repy, repu, and repf1 and 50% of the plasmids of different isolates of x.o.pv.oryzae belonged to type repp. x.c.pv.citri contained plasmids belonging to repf1 and repf11. of the 19 replicon probes used, only 9 (repp, repf1, repf11, repy, repq, repw, repx, and repu) hybridized with various plasmids of xanthomonas. | 1994 | 7899518 |
| characterization of two novel filamentous phages of xanthomonas. | two filamentous phages of xanthomonas campestris pv. vesicatoria and xanthomonas oryzae pv. oryzae were isolated and designated phi xv and phi xo, respectively. they were similar to other filamentous phages of xanthomonas in (i) shape, (ii) restrictive host specificity, (iii) high stability, (iv) an ssdna genome, (v) a dsdna as the replicative form (rf), (vi) propagation without lysis of host cells and (vii) ability to integrate into the host chromosome. these phages showed sequence homology to ... | 1994 | 8077961 |
| identification of the xorii methyltransferase gene and a vsr homolog from xanthomonas oryzae pv. oryzae. | the gene encoding the xorii methyltransferase (m.xorii) was cloned from xanthomonas oryzae pv. oryzae and characterized in escherichia coli. the m.xorii activity was localized to a 3.1 kb bamhi-bstxi fragment, which contained two open reading frames (orfs) of 1272 nucleotides (424 amino acids) and 408 nucleotides (136 amino acids). ten polypeptide domains conserved in other m5 cytosine methyltransferases (mtases) were identified in the deduced amino acid sequence of the 1272 orf. e. coli mrr+ st ... | 1994 | 8078464 |
| isolation and expression in escherichia coli of a xanthomonas oryzae reca-like gene. | the reca gene from the bacterium xanthomonas oryzae pv. oryzae (xoo), a rice pathogen, was cloned based on its ability to complement dna repair defects of escherichia coli reca- mutants. the xoo reca was localized to a 1.3-kb sau3ai-xhoi fragment and, when cloned into pbr322, specifies increased methylmethanesulfonate and mitomycin c resistance to e. coli reca mutants and allows lambda red- gam- to plaque on an e. coli reca- host. an e. coli reca- strain harboring a plasmid containing the xoo re ... | 1993 | 8406033 |
| restoration of pathogenicity of avirulent xanthomonas oryzae pv. oryzae and x. campestris pathovars by reciprocal complementation with the hrpxo and hrpxc genes and identification of hrpx function by sequence analyses. | the molecular basis of pathogenesis by xanthomonas oryzae pv. oryzae has been partly elucidated by the identification of a gene, hrpxo, required for bacterial blight on rice. a mutation in hrpxo results in the loss of pathogenicity on rice and the loss of hypersensitivity on nonhosts such as datura stramonium and radishes. pathogenicity and its ability to cause the hypersensitive reaction is restored by complementing the mutant with the heterologous hrpxc gene derived from x. campestris pv. camp ... | 1993 | 8458844 |
| a receptor kinase-like protein encoded by the rice disease resistance gene, xa21. | the rice xa21 gene, which confers resistance to xanthomonas oryzae pv. oryzae race 6, was isolated by positional cloning. fifty transgenic rice plants carrying the cloned xa21 gene display high levels of resistance to the pathogen. the sequence of the predicted protein, which carries both a leucine-rich repeat motif and a serine-threonine kinase-like domain, suggests a role in cell surface recognition of a pathogen ligand and subsequent activation of an intracellular defense response. characteri ... | 1995 | 8525370 |
| rapid inhibition of protein histidine phosphorylation by uv-irradiation in xanthomonas oryzae pv. oryzae. | exposure of xanthomonas oryzae pv. oryzae cells to 254 nm uv radiation resulted in an alteration of protein phosphorylation. labelling of the phosphohistidine-containing proteins with molecular masses of 81 and 32 kda, named p81 and p32, was rapidly reduced following uv irradiation in the early exponential cells, but the decrease was not detected in mid-exponential cells. mitomycin c, a dna replication inhibitor, and rifampicin, a drug generally used to inhibit rna synthesis and dna replication, ... | 1995 | 8586267 |
| the reca protein as a model molecule for molecular systematic studies of bacteria: comparison of trees of recas and 16s rrnas from the same species. | the evolution of the reca protein was analyzed using molecular phylogenetic techniques. phylogenetic trees of all currently available complete reca proteins were inferred using multiple maximum parsimony and distance matrix methods. comparison and analysis of the trees reveal that the inferred relationships among these proteins are highly robust. the reca trees show consistent subdivisions corresponding to many of the major bacterial groups found in trees of other molecules including the alpha, ... | 1995 | 8587109 |
| heterologous growth phase- and temperature-dependent expression and h2o2 toxicity protection of a superoxide-inducible monofunctional catalase gene from xanthomonas oryzae pv. oryzae. | catalase is an important protective enzyme against h2o2 toxicity. here, we report the characterization of a xanthomonas oryzae pv. oryzae catalase gene (katx). the gene was localized and its nucleotide sequence was determined. the gene codes for a 77-kda polypeptide. the deduced katx amino acid sequence shares regions of high identity with other monofunctional catalases in a range of organisms from bacteria to eukaryotes. the transcriptional regulation of katx was atypical of bacterial monofunct ... | 1996 | 8655557 |
| [a pcr marker-based selection for resistance to bacterial blight in rice]. | molecular marker-based selection in plant breeding requires not only suitable molecular markers closely linked to the known genes, but a simple, economic and reliable analyzing technique. we report here a useful pcr marker for genetic diagnostics in breeding for resistance to rice bacterial blight. xa21 is a newly found gene of rice which confers resistance to bacterial blight caused by xanthomonas oryzae pv. oryzae. we produced two f2 populations between one resistant line irbb21 containing xa2 ... | 1996 | 8695180 |
| cloning and characterization of the rpfc gene of xanthomonas oryzae pv. oryzae: involvement in exopolysaccharide production and virulence to rice. | rpfc is one of a cluster of genes which coordinately regulate the synthesis of extracellular enzymes and exopolysaccharide and pathogenicity in xanthomonas campestris pv. campestris, the black rot pathogen of brassicas. an rpfc homolog which could functionally complement an rpfc mutant of x. campestris pv. campestris was identified in xanthomonas oryzae pv. oryzae and the gene was characterized. mutation of this gene in x. oryzae pv. oryzae had no effect on extracellular enzymes, but exopolysacc ... | 1996 | 8810082 |
| rifampicin: an inhibitor of xp12-specific protein phosphorylation in xanthomonas oryzae pv. oryzae. | phosphorylation of the three xp12-specific phosphoproteins was drastically reduced by rifampicin, an antibiotic that specifically inhibits the host-cell rna polymerase. however, this inhibitory effect could not be found in spontaneous mutants of xanthomonas oryzae pv. oryzae whose rna polymerase are resistant to the drug. the inhibitory effect of rifampicin treatment also resulted suppression of the xp12 multiplication cycle. this implies the physiological significance of this effect and support ... | 1996 | 8837466 |
| the cloned gene, xa21, confers resistance to multiple xanthomonas oryzae pv. oryzae isolates in transgenic plants. | the cloned rice gene, xa21, confers resistance to multiple pathogen isolates of xanthomonas oryzae pv. oryzae in transgenic plants. the resistance phenotype was stably transmitted to t1 progeny and inherited as a single locus. the t1 progeny were tested for resistance to 32 x. oryzae pv. oryzae isolates from eight countries. both the engineered line and the donor line showed resistance to 29 isolates and susceptibility to three isolates. the identical resistance spectrum of both lines indicates ... | 1996 | 8969533 |
| the molecular basis of disease resistance in rice. | the rice gene xa21 conferring resistance to xanthomonas oryzae pv. oryzae (xoo), was isolated using a map-based cloning strategy. compared with previously cloned genes, the structure of xa21 represents a novel class of plant disease r genes encoding a putative receptor kinase (rk). this article proposes a model for the mode of action of xa21 and summarizes our current knowledge of the modular basis of resistance in rice to bacterial leaf blight and blast. | 1997 | 9291971 |
| differential induction of a peroxidase gene family during infection of rice by xanthomonas oryzae pv. oryzae. | induction of peroxidase has been correlated with resistant interactions between rice and xanthomonas oryzae pv. oryzae. to assist in analysis of the role of rice peroxidases in plant defense against the bacterial pathogen, three peroxidase genes, pox22.3, pox8.1, and pox5.1, were identified from a rice cdna library that was constructed from leaves of plants undergoing a resistant reaction. these genes were highly similar in nucleic acid and amino acid sequences and belonged to a gene family. the ... | 1997 | 9304860 |
| the bacterial pigment xanthomonadin offers protection against photodamage. | xanthomonas oryzae pv. oryzae is a bacterial pathogen that causes leaf blight, a serious disease of rice. most members of the genus xanthomonas produce yellow, membrane bound, brominated aryl polyene pigments called xanthomonadins whose functional role is unclear. we find that pigment-deficient mutants of x. oryzae pv. oryzae exhibit hypersensitivity to photobiological damage. a clone containing the xanthomonadin biosynthetic gene cluster alleviates the hypersensitivity of the pigment-deficient ... | 1997 | 9350981 |
| expression of xa1, a bacterial blight-resistance gene in rice, is induced by bacterial inoculation. | the xa1 gene in rice confers resistance to japanese race 1 of xanthomonas oryzae pv. oryzae, the causal pathogen of bacterial blight (bb). we isolated the xa1 gene by a map-based cloning strategy. the deduced amino acid sequence of the xa1 gene product contains nucleotide binding sites (nbs) and a new type of leucine-rich repeats (lrr); thus, xa1 is a member of the nbs-lrr class of plant disease-resistance genes, but quite different from xa21, another bb-resistance gene isolated from rice. inter ... | 1998 | 9465073 |
| characterization and expression analysis of a xanthomonas oryzae pv. oryzae reca. | nucleotide sequence of xanthomonas oryzae pv. oryzae (xoo) dna from psm-a1 was determined and sequence analysis revealed an orf with high homology to reca proteins. expression analysis using an anti-reca antibody demonstrates that mms treatment induces reca in xanthomonas strains but not in an escherichia coli harbouring cloned xoo reca. this indicates the existence of a reca regulatory mechanism in xanthomonas that is not function in e. coli. in xoo, reca was highly induced by treatments with c ... | 1998 | 9465392 |
| n-acylethanolamines: formation and molecular composition of a new class of plant lipids | recently, the biosynthesis of an unusual membrane phospholipid, n-acylphosphatidylethanolamine (nape), was found to increase in elicitor-treated tobacco (nicotiana tabacum l.) cells (k.d. chapman, a. conyers-hackson, r.a. moreau, s. tripathy [1995] physiol plant 95: 120-126). here we report that before induction of nape biosynthesis, n-acylethanolamine (nae) is released from nape in cultured tobacco cells 10 min after treatment with the fungal elicitor xylanase. in radiolabeling experiments [14c ... | 1998 | 9501149 |
| erwinia amylovora secretes dspe, a pathogenicity factor and functional avre homolog, through the hrp (type iii secretion) pathway. | erwinia amylovora was shown to secrete dspe, a pathogenicity factor of 198 kda and a functional homolog of avre of pseudomonas syringae pv. tomato. dspe was identified among the supernatant proteins isolated from cultures grown in an hrp gene-inducing minimal medium by immunodetection with a dspe-specific antiserum. secretion required an intact hrp pathway. | 1998 | 9555912 |
| distribution of xanthomonas oryzae pv. oryzae dna modification systems in asia. | the presence or absence of two dna modification systems, xori and xorii, in 195 strains of xanthomonas oryzae pv. oryzae collected from different major rice-growing countries of asia was assessed. all four possible phenotypes (xori+ xorii+, xori+ xorii-, xori- xorii+ and xori- xorii-) were detected in the population at a ratio of approximately 1:2:2:2. the xori+ xorii+ and xori- xorii+ phenotypes were observed predominantly in strains from southeast asia (philippines, malaysia, and indonesia), w ... | 1998 | 9572933 |
| identification and characterization of a new organic hydroperoxide resistance (ohr) gene with a novel pattern of oxidative stress regulation from xanthomonas campestris pv. phaseoli. | we have isolated a new organic hydroperoxide resistance (ohr) gene from xanthomonas campestris pv. phaseoli. this was done by complementation of an escherichia coli alkyl hydroperoxide reductase mutant with an organic hydroperoxide-hypersensitive phenotype. ohr encodes a 14.5-kda protein. its amino acid sequence shows high homology with several proteins of unknown function. an ohr mutant was subsequently constructed, and it showed increased sensitivity to both growth-inhibitory and killing conce ... | 1998 | 9573147 |
| disassociation of sigma subunit from rna polymerase of xanthomonas oryzae pv. oryzae by phage xp10 infection. | the sigma subunit of xanthomonas oryzae pv. oryzae is disassociated from host rna polymerase after phage xp10 infection. to clarify the possible mechanism for this observation, sigma subunit was purified and an antiserum against sigma subunit was prepared. immunoprecipitation of rna polymerase by the anti-core rna polymerase antiserum, followed by immunoblotting with anti-sigma subunit antibody, revealed that sigma subunit was lost from rna polymerase within 10 minutes after xp10 infection. loss ... | 1998 | 9595658 |
| xa21d encodes a receptor-like molecule with a leucine-rich repeat domain that determines race-specific recognition and is subject to adaptive evolution. | the rice xa21 gene confers resistance to xanthomonas oryzae pv oryzae in a race-specific manner. analysis of the inheritance patterns and resistance spectra of transgenic plants carrying six xa21 gene family members indicated that one member, designated xa21d, displayed a resistance spectrum identical to that observed for xa21 but conferred only partial resistance. xa21d encodes a receptor-like protein carrying leucine-rich repeat (lrr) motifs in the presumed extracellular domain. the xa21d tran ... | 1998 | 9596635 |
| avrxa10 contains an acidic transcriptional activation domain in the functionally conserved c terminus. | the avrxa10 gene of xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, is a member of the avrbs3 avirulence gene family and directs the elicitation of resistance in a gene-for-gene manner on rice lines carrying the resistance gene xa10. the carboxyl (c) terminus of avrxa10 has a previously undescribed domain that is structurally similar to the acidic activation domain of many eukaryotic transcription factors in addition to three nuclear localization signal (nls) sequenc ... | 1998 | 9675896 |
| construction and physiological analysis of a xanthomonas mutant to examine the role of the oxyr gene in oxidant-induced protection against peroxide killing. | we constructed and characterized a xanthomonas campestris pv. phaseoli oxyr mutant. the mutant was hypersensitive to h2o2 and menadione killing and had reduced aerobic plating efficiency. the oxidants' induction of the catalase and ahpc genes was also abolished in the mutant. analysis of the adaptive responses showed that hydrogen peroxide-induced protection against hydrogen peroxide was lost, while menadione-induced protection against hydrogen peroxide was retained in the oxyr mutant. these res ... | 1998 | 9683499 |
| acquisition of certain streptomycin-resistant (str) mutations enhances antibiotic production in bacteria. | physiological differentiation (including antibiotic production) in microorganisms usually starts when cells encounter adverse environmental conditions and is frequently accompanied by an increase in the accumulation of intracellular ppgpp. we have found that the acquisition of certain streptomycin-resistant (str) mutations enables cells to overproduce antibiotics, demonstrating an increase in productivity 5- to 50-fold greater than that of wild-type strains. the frequency of such antibiotic-over ... | 1998 | 9687404 |
| the cyanobacterium synechocystis sp. strain pcc 6803 expresses a dna methyltransferase specific for the recognition sequence of the restriction endonuclease pvui. | by use of restriction endonucleases, the dna of the cyanobacterium synechocystis sp. strain pcc 6803 was analyzed for dna-specific methylation. three different recognition sites of methyltransferases, a dam-like site including n6-methyladenosine and two other sites with methylcytosine, were identified, whereas no activities of restriction endonucleases could be detected in this strain. slr0214, a synechocystis gene encoding a putative methyltransferase that shows significant similarities to c5-m ... | 1998 | 9696758 |
| filamentous bacteriophages of vibrio parahaemolyticus as a possible clue to genetic transmission. | we have previously reported the isolation and characterization of two filamentous bacteriophages of vibrio parahaemolyticus, designated vf12 and vf33. in this study, to understand the potential of these phages as tools for genetic transmission, we investigated the gene structures of replicative-form (rf) dnas of their genomes and the distribution of these dnas on chromosomal and extrachromosomal dnas. the 7,965-bp nucleotide sequences of vf12 and vf33 were determined. an analysis of the overall ... | 1998 | 9748441 |
| hrpw of erwinia amylovora, a new harpin that contains a domain homologous to pectate lyases of a distinct class. | harpins, such as hrpn of erwinia amylovora, are extracellular glycine-rich proteins that elicit the hypersensitive reaction (hr). we identified hrpw of e. amylovora, which encodes a protein similar to known harpins in that it is acidic, rich in glycine and serine, and lacks cysteine. a putative hrpl-dependent promoter was identified upstream of hrpw, and western blot analysis of hrpl mutants indicated that the production of hrpw is regulated by hrpl. hrpw is secreted via the hrp (type iii) pathw ... | 1998 | 9748455 |
| relatedness of strains of xanthomonas fragariae by restriction fragment length polymorphism, dna-dna reassociation, and fatty acid analyses | the levels of relatedness of strains of xanthomonas fragariae collected over several years from locations in canada and the united states were compared by determining fatty acid methyl ester profiles, restriction fragment length polymorphisms (rflp) based on pulsed-field gel electrophoresis (pfge) analysis, and dna-dna reassociation values. based on qualitative and quantitative differences in fatty acid profiles, the strains were divided into nine groups and four groups by the midi "10% rule" an ... | 1998 | 9758826 |
| localized changes in peroxidase activity accompany hydrogen peroxide generation during the development of a nonhost hypersensitive reaction in lettuce | peroxidase activity was characterized in lettuce (lactuca sativa l.) leaf tissue. changes in the activity and distribution of the enzyme were examined during the development of a nonhost hypersensitive reaction (hr) induced by pseudomonas syringae (p. s.) pv phaseolicola and in response to an hrp mutant of the bacterium. assays of activity in tissue extracts revealed ph optima of 4.5, 6.0, 5.5 to 6.0, and 6.0 to 6.5 for the substrates tetramethylbenzidine, guaiacol, caffeic acid, and chlorogenic ... | 1998 | 9808752 |
| construction and physiological analysis of a xanthomonas oryzae pv. oryzae reca mutant. | a xoo reca insertion inactivation mutant was constructed. the mutant, lacking reca, showed increased sensitivity towards mutagen killing. this phenotype could be complemented by a cloned, functional reca. unlike other bacteria, both the reca mutant and the parental strain had similar level of resistance to h2o2 killing and peroxide-induced mutagenesis. | 1998 | 9868770 |
| the structural and functional organization of h-ns-like proteins is evolutionarily conserved in gram-negative bacteria. | the structural gene of the h-ns protein, a global regulator of bacterial metabolism, has been identified in the group of enterobacteria as well as in closely related bacteria, such as erwinia chrysanthemi and haemophilus influenzae. isolated outside these groups, the bph3 protein of bordetella pertussis exhibits a low amino acid conservation with h-ns, particularly in the n-terminal domain. to obtain information on the structure, function and/or evolution of h-ns, we searched for other h-ns-rela ... | 1999 | 9987132 |
| a "defeated" rice resistance gene acts as a qtl against a virulent strain of xanthomonas oryzae pv. oryzae. | the genetic components responsible for qualitative and quantitative resistance of rice plants to three strains (cr4, cxo8, and cr6) of xanthomonas oryzae pv. oryzae (xoo) were investigated using a set of 315 recombinant inbred lines (rils) from the cross lemont (japonica) x teqing (indica) and a complete linkage map with 182 well distributed rflp markers. we mapped a major gene (xa4) and ten quantitative trait loci (qtls) which were largely responsible for segregation of the resistance phenotype ... | 1999 | 10071210 |
| zelkovamycin, a new cyclic peptide antibiotic from streptomyces sp. k96-0670. i. production, isolation and biological properties. | a new antibiotic termed zelkovamycin was isolated from the fermentation broth of streptomyces sp. k96-0670 by solvent extraction, ods column chromatography and preparative hplc. zelkovamycin showed antibacterial activity against xanthomonas oryzae, acholeplasma laidlawii, pyricularia oryzae and staphylococcus aureus. | 1999 | 10092194 |
| the adsorption protein genes of xanthomonas campestris filamentous phages determining host specificity. | gene iii (giii) of philf, a filamentous phage specifically infecting xanthomonas campestris pv. campestris, was previously shown to encode a virion-associated protein (piii) required for phage adsorption. in this study, the transcription start site for the gene and the n-terminal sequence of the protein were determined, resulting in the revision of the translation initiation site from the one previously predicted for this gene. for comparative study, the giii of phixv, a filamentous phage specif ... | 1999 | 10198010 |
| differential regulation of two divergent sinorhizobium meliloti genes for hpii-like catalases during free-living growth and protective role of both catalases during symbiosis. | two catalases, kata and katb, have been detected in sinorhizobium meliloti growing on rich medium. here we characterize a new catalase gene encoding a third catalase (katc). katc activity was detectable only at the end of the stationary phase in s. meliloti growing in minimum medium, whereas kata activity was found during the exponential phase. analysis with a katc-lacz fusion demonstrated that katc expression is mainly regulated at the transcription level. an increase of catalase activity corre ... | 1999 | 10198032 |
| identification of a novel beta-lactamase produced by xanthomonas campestris, a phytopathogenic bacterium. | the xanthomonas campestris pv. campestris 11 chromosome encodes a periplasmic beta-lactamase of 30 kda. gene replacement and complementation confirmed the presence of this enzyme. its deduced amino acid sequence shows identity and conserved domains between it and stenotrophomonas maltophilia l2 and other ambler class a/bush group 2 beta-lactamases. southern hybridization detected a single homologous fragment in each of 12 other xanthomonas strains, indicating that the presence of a beta-lactamas ... | 1999 | 10390247 |
| community analysis of biofilters using fluorescence in situ hybridization including a new probe for the xanthomonas branch of the class proteobacteria. | domain-, class-, and subclass-specific rrna-targeted probes were applied to investigate the microbial communities of three industrial and three laboratory-scale biofilters. the set of probes also included a new probe (named xan818) specific for the xanthomonas branch of the class proteobacteria; this probe is described in this study. the members of the xanthomonas branch do not hybridize with previously developed rrna-targeted oligonucleotide probes for the alpha-, beta-, and gamma-proteobacteri ... | 1999 | 10427047 |
| development and application of pathovar-specific monoclonal antibodies that recognize the lipopolysaccharide o antigen and the type iv fimbriae of xanthomonas hyacinthi. | the objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (mabs). mice were immunized with a crude cell wall preparation (shear fraction) from xanthomonas hyacinthi and with purified type iv fimbriae. hybridomas were screened for a positive reaction with x. hyacinthi cells or fimbriae and for a negative reaction with x. translucens pv. graminis or erwinia carotovora subsp. carotovora. nine mabs recognized fim ... | 1999 | 10473431 |
| a transposon insertion in the gumg homologue of xanthomonas oryzae pv. oryzae causes loss of extracellular polysaccharide production and virulence. | xanthomonas oryzae pv. oryzae causes a serious disease of rice called bacterial leaf blight. it produces copious amounts of extracellular polysaccharide (eps). an eps- and virulence-deficient mutant of x. oryzae pv. oryzae was isolated by tn5 mutagenesis. the mutant allele in this strain was cloned by transposon tagging in the escherichia coli vector pbluescript and the dna sequences flanking the transposon insertion site were determined. computer-based similarity searches in the dna database us ... | 1999 | 10481086 |
| the c terminus of avrxa10 can be replaced by the transcriptional activation domain of vp16 from the herpes simplex virus. | the avirulence gene avrxa10 of xanthomonas oryzae pv oryzae directs the elicitation of resistance in a gene-for-gene manner in rice lines carrying the resistance gene xa10. we have localized a transcriptional activator domain in the c terminus of avrxa10 by using amino acid replacement mutagenesis. one mutant, with replacements at three hydrophobic amino acid residues in the c-terminal domain, was defective for transcriptional activation in yeast and avirulence activity in rice. the activation d ... | 1999 | 10488234 |
| short communication: developmental control of xa21-mediated disease resistance in rice. | the rice resistance gene xa21 confers resistance against the bacterial pathogen xanthomonas oryzae pv. oryzae (xoo). the molecular genetic mechanism controlling the integration of the xa21-mediated disease resistance response with the developmental program in rice is under study in this model system. reproducible means of infecting plants at certain developmental stages were designed based on the timing of full expansion of the leaf. xa21-resistance progressively increases from the susceptible j ... | 1999 | 10571882 |
| identification of two novel hrp-associated genes in the hrp gene cluster of xanthomonas oryzae pv. oryzae. | we have cloned a hrp gene cluster from xanthomonas oryzae pv. oryzae. bacteria with mutations in the hrp region have reduced growth in rice leaves and lose the ability to elicit a hypersensitive response (hr) on the appropriate resistant cultivars of rice and the nonhost plant tomato. a 12,165-bp portion of nucleotide sequence from the presumed left end and extending through the hrpb operon was determined. the region was most similar to hrp genes from xanthomonas campestris pv. vesicatoria and r ... | 2000 | 10714988 |
| superoxide dismutase activity in pseudomonas putida affects utilization of sugars and growth on root surfaces. | to investigate the role of superoxide dismutases (sod) in root colonization and oxidative stress, mutants of pseudomonas putida lacking manganese-superoxide dismutase (mnsod) (soda), iron-superoxide dismutase (fesod) (sodb), or both were generated. the soda sodb mutant did not grow on components washed from bean root surfaces or glucose in minimal medium. the sodb and soda sodb mutants were more sensitive than wild type to oxidative stress generated within the cell by paraquat treatment. in sing ... | 2000 | 10742227 |
| mutants of xanthomonas oryzae pv. oryzae deficient in general secretory pathway are virulence deficient and unable to secrete xylanase. | xanthomonas oryzae pv. oryzae (xoo) causes bacterial leaf blight, a serious disease of rice. a virulence- and xylanase-deficient mutant of xoo was isolated following ethyl methane sulfonate (ems) mutagenesis. a cosmid clone that restored virulence and xylanase secretion was obtained from a genomic library by functional complementation. transposon mutagenesis and marker exchange studies revealed genes on the cloned dna that were required for xylanase production and virulence. sequence analysis wi ... | 2000 | 10755302 |
| members of the arabidopsis hrt/rpp8 family of resistance genes confer resistance to both viral and oomycete pathogens. | turnip crinkle virus (tcv) inoculation onto tcv-resistant arabidopsis leads to a hypersensitive response (hr) controlled by the dominant gene hrt. hrt is a member of the class of resistance (r) genes that contain a leucine zipper, a nucleotide binding site, and leucine-rich repeats. the chromosomal position of hrt and its homology to resistance gene rpp8 and two rpp8 homologs indicate that unequal crossing over and gene conversion may have contributed to hrt evolution. rpp8 confers resistance to ... | 2000 | 10810142 |
| thr38 and ser198 are pto autophosphorylation sites required for the avrpto-pto-mediated hypersensitive response. | the tomato pto kinase confers resistance to pseudomonas syringae pv. tomato expressing the avrpto protein. to elucidate the role of pto autophosphorylation in disease resistance, eight sites autophosphorylated by pto in vitro were identified by a combination of hplc purification of tryptic phosphopeptides, maldi-tof/ms analysis and edman degradation. mutational analysis of the autophosphorylation sites revealed that pto residues thr38 and ser198 are required for avrpto-pto- mediated elicitation ... | 2000 | 10811617 |
| prey range characterization, ribotyping, and diversity of soil and rhizosphere bdellovibrio spp. isolated on phytopathogenic bacteria. | thirty new bdellovibrio strains were isolated from an agricultural soil and from the rhizosphere of plants grown in that soil. using a combined molecular and culture-based approach, we found that the soil bdellovibrios included subpopulations of organisms that differed from rhizosphere bdellovibrios. thirteen soil and seven common bean rhizosphere bdellovibrio strains were isolated when pseudomonas corrugata was used as prey; seven and two soil strains were isolated when erwinia carotovora subsp ... | 2000 | 10831412 |
| mutations in oxyr resulting in peroxide resistance in xanthomonas campestris. | a spontaneous xanthomonas campestris pv. phaseoli h(2)o(2)-resistant mutant emerged upon selection with 1 mm h(2)o(2). in this report, we show that growth of this mutant under noninducing conditions gave high levels of catalase, alkyl hydroperoxide reductase (ahpc and ahpf), and oxyr. the h(2)o(2) resistance phenotype was abolished in oxyr-minus derivatives of the mutant, suggesting that elevated levels and mutations in oxyr were responsible for the phenotype. nucleotide sequence analysis of the ... | 2000 | 10851004 |
| the virulence factor avrxa7 of xanthomonas oryzae pv. oryzae is a type iii secretion pathway-dependent nuclear-localized double-stranded dna-binding protein. | avrxa7 is a member of the avrbs3 avirulence gene family, which encodes proteins targeted to plant cells by a type iii secretion apparatus. avrxa7, the product of avrxa7, is also a virulence factor in strain pxo86 of xanthomonas oryzae pv. oryzae. avirulence and virulence specificities are associated with the central repeat domain, which, in avrxa7, consists of 25.5 direct repeat units. mutations in three c-terminal nuclear localization signal motifs eliminated avirulence and virulence activities ... | 2000 | 10931960 |
| stationary-phase variation due to transposition of novel insertion elements in xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. spontaneous mutants which are deficient for virulence and extracellular polysaccharide (eps) production accumulate in large numbers in stationary-phase cultures of this bacterium, a phenomenon which we have called stationary-phase variation. a clone (psd1) carrying the eps biosynthetic gene (gum) cluster of x. oryzae pv. oryzae restored eps production and virulence to several spv (for stationary-phase variatio ... | 2000 | 10940020 |
| exposure of phytopathogenic xanthomonas spp. to lethal concentrations of multiple oxidants affects bacterial survival in a complex manner. | during plant-microbe interactions and in the environment, xanthomonas campestris pv. phaseoli is likely to be exposed to high concentrations of multiple oxidants. here, we show that simultaneous exposures of the bacteria to multiple oxidants affects cell survival in a complex manner. a superoxide generator (menadione) enhanced the lethal effect of an organic peroxide (tert-butyl hydroperoxide) by 1, 000-fold; conversely, treatment of cells with menadione plus h(2)o(2) resulted in 100-fold protec ... | 2000 | 10966423 |
| [introduction of wide spectrum rice bacterial blight resistance gene xa21 into two-line genic male sterile rice variety pei'ai 64s]. | agrobacterium-mediated transformation of two-line genic male sterile indica rice variety pei'ai 64s was conducted using a cloned gene, xa21, as the foreign gene and mature embryo calli as the recipients. a total of 46 transgenic plants had been obtained. the pcr analysis and southern blotting showed the integration of xa21 gene into the genome the transgenic plants. results of inoculation with philippine race 6 of xanthomonas oryzae pv. oryzae indicated that most of transgenic plants obtained hi ... | 2000 | 10976312 |
| isolation and characterization of disease resistance gene homologues from rice cultivar ir64. | we initiated a search for disease resistance (r) gene homologues in rice cultivar ir64, one of the most agronomically important rice varieties in the world, with the assumption that some of these homologues would correspond to previously identified disease resistance loci. a family of rice r gene homologues was identified using the arabidopsis nbs-lrr disease resistance gene rps2 as a hybridization probe. because member genes of this rice r gene family exhibit features characteristic of the nbs- ... | 2000 | 11024284 |
| hrt gene function requires interaction between a nac protein and viral capsid protein to confer resistance to turnip crinkle virus. | an arabidopsis protein was found to interact specifically with the capsid protein (cp) of turnip crinkle virus (tcv) through yeast two-hybrid screening. this protein, designated tip (for tcv-interacting protein), was found to be a member of the recently recognized nac family of proteins. nac proteins have been implicated in the regulation of development of plant embryos and flowers. tip alone was able to activate expression of reporter genes in yeast if fused to a dna binding domain, suggesting ... | 2000 | 11041886 |
| transgenic expression of cecropin b, an antibacterial peptide from bombyx mori, confers enhanced resistance to bacterial leaf blight in rice. | the short persistence of cecropin b peptide in plants, due to post-translational degradation, is a serious impediment in its effective utilization for developing bacterial resistance transgenic plants. two dna constructs encoding the full-length precursor of cecropin b peptide and the mature sequence of cecropin b peptide preceded by a signal peptide derived from rice chitinase gene were transformed in rice. the differences in the transcriptional levels in independent transgenic lines showed mod ... | 2000 | 11056212 |
| a xanthomonas alkyl hydroperoxide reductase subunit c (ahpc) mutant showed an altered peroxide stress response and complex regulation of the compensatory response of peroxide detoxification enzymes. | alkyl hydroperoxide reductase subunit c (ahpc) is the catalytic subunit responsible for alkyl peroxide metabolism. a xanthomonas ahpc mutant was constructed. the mutant had increased sensitivity to organic peroxide killing, but was unexpectedly hyperresistant to h(2)o(2) killing. analysis of peroxide detoxification enzymes in this mutant revealed differential alteration in catalase activities in that its bifunctional catalase-peroxidase enzyme and major monofunctional catalase (kat1) increased s ... | 2000 | 11073935 |
| structure and sequence analysis of yersinia yada and moraxella uspas reveal a novel class of adhesins. | the non-fimbrial adhesins, yada of enteropathogenic yersinia species, and uspa1 and uspa2 of moraxella catarrhalis, are established pathogenicity factors. in electron micrographs, both surface proteins appear as distinct 'lollipop'-shaped structures forming a novel type of surface projection on the outer membranes. these structures, amino acid sequence analysis of these molecules and yada gene manipulation suggest a tripartite organization: an n-terminal oval head domain is followed by a putativ ... | 2000 | 11080146 |
| predicting durability of a disease resistance gene based on an assessment of the fitness loss and epidemiological consequences of avirulence gene mutation. | durability of plant disease resistance (r) genes may be predicted if the cost of pathogen adaptation to overcome resistance is understood. adaptation of the bacterial blight pathogen, xanthomonas oryzae pv. oryzae (xoo), to virulence in rice is the result of the loss of pathogen avirulence gene function, but little is known about its effect on aggressiveness under field conditions. we evaluated the cost in pathogenic fitness (aggressiveness and persistence) associated with adaptation of xoo to v ... | 2000 | 11095723 |
| xanthomonas oryzae pv. oryzae avirulence genes contribute differently and specifically to pathogen aggressiveness. | genomic copies of three xanthomonas oryzae pv. oryzae avirulence (avr) genes, avrxa7, avrxal0, and avrxa5, and four homologous genes, ab3.5, ab3.6, ab4.3, and ab4.5, were mutagenized individually or in combination to study the roles of avr genes in one component of pathogen fitness, i.e., aggressiveness or the amount of disease x. oryzae pv. oryzae causes in susceptible rice lines. these x. oryzae pv. oryzae genes are members of the highly related xanthomonas avrbs3 gene family. compared to the ... | 2000 | 11106024 |
| pigment and virulence deficiencies associated with mutations in the aroe gene of xanthomonas oryzae pv. oryzae. | xanthomonadins are yellow, membrane-bound pigments produced by members of the genus xanthomonas. we identified an ethyl methanesulfonate-induced xanthomonas oryzae pv. oryzae mutant (bxo65) that is deficient for xanthomonadin production and virulence on rice, as well as auxotrophic for aromatic amino acids (pig(-) vir(-) aro(-)). reversion analysis indicated that these multiple phenotypes are due to a single mutation. a genomic library of the wild-type strain was used to isolate a 7.0-kb clone t ... | 2001 | 11133452 |
| isolation of segments of homologous genes with only one conserved amino acid region via pcr. | we present a method which allows the isolation of fragments from genes coding for homologous proteins via pcr when only one block of conserved amino acids is available. sets of degenerated primers are defined by reverse translation of the conserved amino acids such that each set contains not more than 128 different sequences. the second primer binding site is provided by a special cassette that is designed such that it does not allow binding of the second primer prior to being copied by dna synt ... | 2001 | 11139638 |
| essential role of the small gtpase rac in disease resistance of rice. | production of reactive oxygen intermediates (roi) and a form of programmed cell death called hypersensitive response (hr) are often associated with disease resistance of plants. we have previously shown that the rac homolog of rice, osrac1, is a regulator of roi production and cell death in rice. here we show that the constitutively active osrac1 (i) causes hr-like responses and greatly reduces disease lesions against a virulent race of the rice blast fungus; (ii) causes resistance against a vir ... | 2001 | 11149940 |