Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| 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 |
| increased activity of a cationic peroxidase associated with an incompatible interaction between xanthomonas oryzae pv oryzae and rice (oryza sativa). | rice (oryza sativa l.) cultivar cas 209 carries the gene xa-10 for resistance to race 2 of xanthomonas oryzae pv oryzae, the bacterial blight pathogen. when seedling leaves of cas 209 plants were infiltrated with bacterial cell suspensions of strain pxo86(rif) (race 2, incompatible), total peroxidase activity in extracts from extracellular spaces increased almost threefold between 16 and 24 hours after inoculation. the increase in total peroxidase activity in extracellular extracts was correlate ... | 1992 | 16668969 |
| 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 |
| 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 |
| 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 |
| relationship between phylogeny and pathotype for the bacterial blight pathogen of rice. | several transposable elements were isolated from the genome of xanthomonas oryzae pv. oryzae. these elements and an avirulence gene isolated from x. oryzae pv. oryzae were used as hybridization probes for a collection of x. oryzae pv. oryzae strains from the philippines. each of the sequences was present in multiple copies in all strains examined and showed distinct patterns of hybridizing bands. phenograms were derived from the restriction fragment length polymorphism data obtained for each of ... | 1994 | 16349380 |
| unusual growth phase and oxygen tension regulation of oxidative stress protection enzymes, catalase and superoxide dismutase, in the phytopathogen xanthomonas oryzae pv. oryzae. | the enzymes catalase and superoxide dismutase play major roles in protecting phytopathogenic bacteria from oxidative stress. in xanthomonas species, these enzymes are regulated by both growth phase and oxygen tension. the highest enzyme levels were detected within 1 h of growth. continued growth resulted in a decline of both enzyme activities. high oxygen tension was an inducing signal for both enzyme activities. an 80,000-da monofunctional catalase and a manganese superoxide dismutase were the ... | 1995 | 16534917 |
| 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 |
| 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 |
| genetic diversity of xanthomonas oryzae pv. oryzae in asia. | restriction fragment length polymorphism and virulence analyses were used to evaluate the population structure of xanthomonas oryzae pv. oryzae, the rice bacterial blight pathogen, from several rice-growing countries in asia. two dna sequences from x. oryzae pv. oryzae, is1112, an insertion sequence, and avrxa10, a member of a family of avirulence genes, were used as probes to analyze the genomes of 308 strains of x. oryzae pv. oryzae collected from china, india, indonesia, korea, malaysia, nepa ... | 1995 | 16534980 |
| 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 |
| changes in the plasma membrane distribution of rice phospholipase d during resistant interactions with xanthomonas oryzae pv oryzae. | phospholipase d (pld; ec 3.1.4.4), which hydrolyzes phospholipids to generate phosphatidic acid, was examined in rice leaves undergoing susceptible or resistant interactions with xanthomonas oryzae pv oryzae. rna analysis of leaves undergoing resistant interactions revealed different expression patterns for pld over 5 days relative to control plants or those undergoing susceptible interactions. by using an activity assay and immunoblot analysis, we identified three forms of pld (1, 2, and 3). pl ... | 1996 | 12239412 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| genomic variability of the xanthomonas pathovar mangiferaeindicae, agent of mango bacterial black spot. | the genetic diversity of 138 strains of the xanthomonas pathovar mangiferaeindicae, which were isolated from three different hosts (mango, ambarella, and pepper tree) in 14 different countries, was assessed with restriction fragment length polymorphism markers. an analysis of patterns obtained by hybridization with an hrp cluster probe from xanthomonas oryzae pv. oryzae separated 11 of the strains from all of the other strains, which suggested that these 11 strains may not be xanthomonas pv. man ... | 1997 | 16535490 |
| genetic diversity within the population of xanthomonas oryzae pv. oryzae in india. | abstract xanthomonas oryzae pathovar oryzae causes a serious disease of rice in india and is endemic in all of the major rice-growing areas of the country. sixty-seven x. oryzae pv. oryzae strains, collected mostly in 1994 and 1995, from 18 locations in india were analyzed by dna fingerprinting methods using two separate repeat element probes from the x. oryzae pv. oryzae genome. these results show that strains belonging to a single pathogen lineage can be isolated from 16 of the 18 locations sa ... | 1997 | 18945099 |
| movement of xanthomonas oryzae pv. oryzae in southeast asia detected using pcr-based dna fingerprinting. | abstract two outwardly directed primers complementary to sequences in is1112, a repetitive element isolated from xanthomonas oryzae pv. oryzae, were used to fingerprint dna from a set of 71 bacterial blight pathogen strains using polymerase chain reaction (pcr), pcr-based restriction analysis, and ligation-mediated pcr. to allow amplification of long dna fragments, standard amplification conditions were altered to increase the ph, add dimethylsulfoxide, decrease denaturation time, and increase e ... | 1997 | 18945173 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| [purification and partial characterization of antagonistic proteins from bacillus subtilis b034]. | bacillus subtilis b034, an antagonistic bacteria isolated from the phyllosphere of rice, strongly inhibits the growth of xanthomonas oryzae pv. oryzae which causes the rice bacterial blight. crude extract was obtained by precipitation of the cell-free culture of b034 with 70% saturated (nh4)2so4. the suspension of the precipitate strongly inhibits xanthomonas oryzae pv. o-ryzae, and it is thermostable, resistant to trypsin, partial sensitive to proteinase k, pronase e and chloroform. its active ... | 1999 | 12555573 |
| 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 |
| 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 |
| 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 |
| 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 |
| genotypic and pathotypic diversity in xanthomonas oryzae pv. oryzae in nepal. | abstract among the 171 strains of xanthomonas oryzae pv. oryzae (the bacterial blight pathogen of rice) collected from eight rice-producing zones in nepal, 31 molecular haplotypes were distinguished using two polymerase chain reaction-based assays. six common haplotypes represented nearly 63% of the strains, and some haplotypes were geographically dispersed. multiple correspondence analysis divided the collection into five putative genetic lineages. lineages 1, 2, and 4 were the most frequently ... | 1999 | 18944682 |
| primary disease gradients of bacterial blight of rice. | abstract the dispersal potential of xanthomonas oryzae pv. oryzae, causal agent of bacterial blight of rice (oryzae sativa), was investigated through measurement of primary disease gradients. plants within individual hills of rice were inoculated, and the number of new lesions in the primary generation of dispersal from these inoculated sources was counted. two dispersal models that can describe the number of infections at the source (the kiyosawa and shiyomi and the modified gregory) were fit t ... | 1999 | 18944805 |
| distribution of xanthomonas oryzae pv. oryzae strains virulent to xa21 in korea. | abstract strains of xanthomonas oryzae pv. oryzae that are virulent to rice lines carrying the xa21 resistance gene were widely distributed in korea. a total of 105 strains collected during 1987 to 1996 in korea was characterized by pathogenicity tests and restriction fragment length polymorphism analysis of the xorii methyltransferase (xoriim) and avrxa10 genes. although the lesion lengths on rice line irbb21, which carries xa21, decreased as plant age increased, resistance and susceptibility o ... | 1999 | 18944737 |
| genetic diversity of xanthomonas oryzae pv. oryzae strains from sri lanka. | abstract sixty strains of xanthomonas oryzae pv. oryzae, collected from 29 locations in sri lanka in 1995, were analyzed by restriction fragment length polymorphism using either polymerase chain reaction-amplified 16s and 23s rdna or the repetitive dna element is1112 from x. oryzae pv. oryzae as hybridization probes. two different ribogroups were observed in the sri lankan strains using rdna probes, whereas five clusters were identified by the is1112 probe. bootstrap analysis revealed that the f ... | 2000 | 18944593 |
| 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 |
| 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 |
| [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 |
| some tryptophan pathways in the phytopathogen xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae, the causal organism of bacterial blight of rice which produces leaf blight as well as kresek (wilt) symptoms in plants were tested for indole, auxin production in culture supplemented with l-tryptophan. on the basis of indoleacetic acid (iaa) production the isolates were grouped into iaa-positive and iaa-negative. out of 17 isolates, 11 were iaa-positive while 6 were iaa-negative. the isolates metabolized tryptophan through two different routes and the isolates var ... | 2000 | 11501419 |
| 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 |
| [activities of superoxide dismutase in xanthomonas oryzae pv. oryzae and its induction]. | the activities of superoxide dismutase(sod) in xanthomonas oryzae pv. oryzae were determined to demonstrate the correlation of sod activities with the bacterial virulence. in liquid culture, sod activities of the tested strains reached the maxima at the end of lag phase and then declined. the virulent strain pxo99a showed higher sod activities than the avirulent strain pxo99a (pbuavr xa10.f1). analysis on the subcellular location indicated that sod activities detected from the cytoplasm and peri ... | 2000 | 12548996 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| chromosome landing at the bacterial blight resistance gene xa4 locus using a deep coverage rice bac library. | xa4 is a dominantly inherited rice gene that confers resistance to philippine race 1 of the bacterial blight pathogen xanthomonas oryzae pv. oryzae in rice. in order to isolate the gene by positional cloning, a bacterial artificial chromosome (bac) library was constructed from genomic dna isolated from an xa4-harboring accession, irbb56. the library contains 55,296 clones with an average insert size of 132 kb, providing 14 rice genome equivalents. three dna markers closely linked to xa4 were use ... | 2001 | 11370857 |
| are the dominant and recessive plant disease resistance genes similar? a case study of rice r genes and xanthomonas oryzae pv. oryzae races. | the resistance of rice to its bacterial blight pathogen xanthomonas oryzae pv. oryzae (xoo) has both qualitative and quantitative components that were investigated using three near-isogenic line sets for four resistance (r) genes (xa4, xa5, xa13, and xa21) and 12 xoo races. our results indicate that these two resistance components of rice plants were associated with the properties of the r genes. the qualitative component of the r genes was reflected by their large effects against corresponding ... | 2001 | 11606550 |
| construction and characterization of a xanthomonas oryzae pv. oryzae bacterial artificial chromosome library. | xanthomonas oryzae pv. oryzae is an important plant pathogen which causes bacterial blight of rice. to facilitate genome studies of this bacterium, we have constructed a bacterial artificial chromosome (bac) library of strain maff 311018. it consisted of 750 clones representing 16 genome equivalents, and had an insert size ranging from 20 to 220 kb with an average size of 107 kb. this library is the first to be constructed from a x. oryzae pv. oryzae strain. the usefulness of this library was de ... | 2001 | 11410350 |
| dissection of defence response pathways in rice. | the cloning of major resistance genes has led to a better understanding of the molecular biology of the steps for induction of resistance, yet much remains to be discovered about the downstream genes that collectively confer resistance, i.e. the defence response (dr) genes. we are dissecting the pathways contributing to resistance in rice by identifying a collection of mutants with deletions or other structural rearrangements in dr genes. the collection of rice mutants has been screened for many ... | 2001 | 11387980 |
| detection of xanthomonas oryzae pv. oryzae in artificially inoculated and naturally infected rice seeds and plants by molecular techniques. | a polymerase chain reaction (pcr) technique was developed for detecting the presence of xanthomonas oryzae pv. oryzae, the bacterial leaf blight (blb) pathogen in rice seed and for studying the transmission of this bacterium from seed to plant. primers txt and txt4r from an insertion sequence (is1113) of the pathogen were used to amplify a 964-bp dna fragment. a combined biological and enzymatic amplification (bio-pcr) technique was used to detect the pathogen in naturally infected seed. the lev ... | 2001 | 11549016 |
| exopolysaccharides of xanthomonas pathovar strains that infect rice and wheat crops. | in order to understand the mode of action of the taxonomically related pathogens xanthomonas campestris pv. translucens, xanthomonas oryzae pv. oryzae, and xanthomonas oryzae pv. oryzicola, which attack wheat and rice crops, we examined the compositional differences of their exopolysaccharides (epss). maximum production of polysaccharide in shake cultures of these pathogens was observed between 24 and 72 h. x. campestris pv. translucens, the leaf streak pathogen of wheat, produced a higher amoun ... | 2001 | 11525629 |
| identification of a h+/glucose and galactose symporter gene glt from xanthomonas oryzae pv. oryzae. | we identified a glucose and galactose transporter gene from the plant-pathogenic bacterium xanthomonas oryzae pv. oryzae. sequence analysis indicated that the gene, named glt, encoded a polypeptide of 592 amino acid residues and the product was significantly homologous with members of the na+/glucose cotransporter (sglt) family from mammalian and bacterial origin, especially with vsglt from vibrio parahaemolyticus (50% identity). glt functioned as a glucose and galactose transporter in an escher ... | 2001 | 11529561 |
| marker assisted selection of bacterial blight resistance genes in rice. | bacterial leaf blight caused by xanthomonas oryzae pv. oryzae is one of the most important diseases affecting rice production in asia. we were interested in surveying rice genotypes that are popularly used in the indian breeding program for conferring resistance to bacterial blight, using 11 stms and 6 sts markers. the basis of selection of these dna markers was their close linkage to xa5, xa13, and xa21 genes and their positions on the rice genetic map relative to bacterial blight resistance ge ... | 2001 | 11590832 |
| characterization of xanthomonas oryzae pv. oryzae recx, a gene that is required for high-level expression of reca. | analysis of the nucleotide sequence downstream from the xanthomonas oryzae pv. oryzae reca gene reveals two orfs designated orfx and recx. the former has the potential to code for a 5.6 kda protein of unknown function while the latter encodes for a putative 14.6 kda protein with homology to recx from various bacteria. northern blot analysis and rt-pcr results show that reca-orfx-recx are co-regulated and arranged in an operon. a recx mutant was constructed. the mutant has no obvious growth defec ... | 2001 | 11728720 |
| novel genomic locus with atypical g+c content that is required for extracellular polysaccharide production and virulence in xanthomonas oryzae pv. oryzae. | three exopolysaccharide (eps)- and virulence-deficient mutants of xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight of rice, were isolated by tn5 mutagenesis. these insertions are not located within the gum gene cluster. a 40-kb cosmid clone that restored eps production and virulence to all three mutants was isolated, and the three transposon insertions were localized to contiguous 4.3- and 3.5-kb ecori fragments that are included in this clone. sequence data indicate that ... | 2001 | 11763133 |
| a 3.1-kb genomic fragment of bacillus subtilis encodes the protein inhibiting growth of xanthomonas oryzae pv. oryzae. | to clone genes of bacillus subtilis encoding peptides that inhibit the growth of xanthomonas orzae pv. oryzae (xoo). | 2001 | 11851812 |
| effect of phenol on protein and amino acid content of xanthomonas oryzae pv. oryzae. | leaf blight disease of rice (oryza sativa) is caused by the bacterium xanthomonas oryzae pv. oryzae. phenol (1 to 4 mm) induced changes in protein profiles of x. o. pv. oryzae and a stress protein with a molecular mass of 69,000 appeared. hplc analysis indicated occurrence of amino acids such as asparagine, alanine, methionine and cystine in phenol treated cells. proton nmr analysis also revealed variation on the presence of amino acids in the cells treated with phenol. | 2001 | 11883515 |
| effect of phenol on lipid and fatty acid profile of xanthomonas oryzae pv. oryzae. | effect of phenol on total lipid and fatty acid composition of xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice (oryzae sativa) was studied. lipid level was low in phenol treated cells. number of fatty acids detected from phenol treated cells was more than those found in untreated cells as revealed by gas chromatography. pentadecanoic acid (c15:0), linolenic acid (c18:3) and behenic acid (c22:0) were present only in the treated cells. palmitic acid which is usually foun ... | 2001 | 11883516 |
| vascular defense responses in rice: peroxidase accumulation in xylem parenchyma cells and xylem wall thickening. | the rice bacterial blight pathogen xanthomonas oryzae pv. oryzae is a vascular pathogen that elicits a defensive response through interaction with metabolically active rice cells. in leaves of 12-day-old rice seedlings, the exposed pit membrane separating the xylem lumen from the associated parenchyma cells allows contact with bacterial cells. during resistant responses, the xylem secondary walls thicken within 48 h and the pit diameter decreases, effectively reducing the area of pit membrane ex ... | 2001 | 11768536 |
| 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 a xanthomonas oryzae pv. oryzae flagellar operon region and molecular characterization of flhf. | an 8.1-kb dna fragment from xanthomonas oryzae pv. oryzae that contains six open reading frames (orf) was cloned. the orf encodes proteins similar to flagellar proteins flhb, flha, flhf, and flia, plus two proteins of unknown function, orf234 and orf319, from bacillus subtilis and other organisms. these orf have a similar genomic organization to those of their homologs in other bacteria. theflhf gene product, flhf, has a gtp-binding motif conserved in its homologs. unlike its homologs, however, ... | 2001 | 11204784 |
| molecular characterization of the cdna encoding an acidic isoform of pr-1 protein in rice. | rice cdna encoding an acidic type of pathogenesis-related protein-1 (pr-1a) was cloned and characterized. the deduced pr-1a protein consisted of 168 amino acid residues, including 24 hydrophobic signal sequences at the n-terminus. the predicted molecular mass of the pr-1a was 15,728 da with a theoretical pi of 4.5, an indication of an acidic protein. the pr-la showed high homology to an acidic pr-1 of zea mays (74%) and a previously identified basic type pr-1 of rice (64%). both rice pr-1 and pr ... | 2001 | 11266113 |
| xanthomonas oryzae pv. oryzae reca is transcribed and regulated from multiple promoters. | transcription regulation of xanthomonas oryzae pv. oryzae reca was characterized. primer extension experiments showed that reca is transcribed from three promoters designated p1, p2 and p3. the sequences of -10 and -35 regions of these promoters have moderate homology to the proposed consensus sequence for a xanthomonas promoter. putative sos boxes were identified in the vicinity of p1 and p2 promoters. deletion analysis and in vivo monitoring of promoter activity of these promoters revealed tha ... | 2001 | 11287143 |
| transgenic rice plants expressing the ferredoxin-like protein (ap1) from sweet pepper show enhanced resistance to xanthomonas oryzae pv. oryzae. | we used particle bombardment to cotransform mature seed-derived rice callus (oryza sativa l., ssp. japonica, cv. eyi 105) with plasmids containing the linked marker genes gusa and hpt, and the ap1 gene encoding an amphipathic protein previously shown to delay the hypersensitive response induced in non-host plants by the pathogen pseudomonas syringae pv. syringae (pss). thirty-two independent lines of transgenic rice plants were regenerated, and 27 of these lines carried all three transgenes as s ... | 2001 | 11297801 |
| evidence for a disease-resistance pathway in rice similar to the npr1-mediated signaling pathway in arabidopsis. | the arabidopsis npr1/nim1 gene is a key regulator of systemic acquired resistance (sar). over-expression of npr1 leads to enhanced resistance in arabidopsis. to investigate the role of npr1 in monocots, we over-expressed the arabidopsis npr1 in rice and challenged the transgenic plants with xanthomonas oryzae pv. oryzae (xoo), the rice bacterial blight pathogen. the transgenic plants displayed enhanced resistance to xoo. rna blot hybridization indicates that enhanced resistance requires expressi ... | 2001 | 11489188 |
| genes expressed during early stages of rice infection with the rice blast fungus magnaporthe grisea. | summary a system-wide approach was adopted to further elucidate mechanisms regulating disease outcome between rice and the fungal pathogen magnaporthe grisea. first, a cdna library was constructed from m. grisea infected rice at 48 h post-inoculation. the 5' end-sequencing of 619 randomly selected clones revealed 359 expressed sequence tags (ests) that had not previously been described. a total of 124 from 260 ests with high and moderate similarity scores, based on blastx, were organized into ca ... | 2001 | 20573024 |
| genetic locus encoding functions involved in biosynthesis and outer membrane localization of xanthomonadin in xanthomonas oryzae pv. oryzae. | xanthomonadins are membrane-bound, brominated, aryl-polyene pigments specific to the genus xanthomonas. we have characterized a genetic locus (pig) from xanthomonas oryzae pv. oryzae which contains four open reading frames (orfs) that are essential for xanthomonadin production. three of these orfs are homologous to acyl carrier proteins, dehydratases, and acyl transferases, suggesting a type ii polyketide synthase pathway for xanthomonadin biosynthesis. the fourth orf has no homologue in the dat ... | 2002 | 12057948 |
| [identification of a resistance gene to bacterial blight (xanthomonas oryzae pv. oryzae) in a somaclonal mutant hx-3 of indica rice]. | using the mature embryo of a susceptible rice variety minghui 63 as the explant, we have obtained a somaclonal mutant hx-3 through selection in vitro, which has showed resistance to bacterial blight. in 8 successive years, the resistance of r1 to r9 generations of hx-3 was identified by zj173, a typical bacterial blight strain in yangtsu river valley, and the results showed that the resistance of hx-3 was stable and heritable. genetic analysis also indicated that the resistance of hx-3 to bacter ... | 2002 | 11901997 |
| the xanthomonas oryzae pv. lozengeoryzae raxp and raxq genes encode an atp sulphurylase and adenosine-5'-phosphosulphate kinase that are required for avrxa21 avirulence activity. | xanthomonas oryzae pv. oryzae (xoo) philippine race 6 (pr6) is unable to cause bacterial blight disease on rice lines containing the rice resistance gene xa21 but is virulent on non-xa21 rice lines, indicating that pr6 carries avirulence (avrxa21) determinants required for recognition by xa21. here we show that two xoo genes, raxp and raxq, are required for avrxa21 activity. raxp and raxq, which reside in a genomic cluster of sulphur assimilation genes, encode an atp sulphurylase and aps (adenos ... | 2002 | 11967067 |
| fine genetic mapping and physical delimitation of the lesion mimic gene spl11 to a 160-kb dna segment of the rice genome. | the rice lesion mimic mutant spl11 was previously found to confer broad-spectrum disease resistance to both magnaporthe grisea and xanthomonas oryzae pv. oryzae. to better understand the molecular basis underlying cell death and disease resistance in rice, a map-based cloning strategy has been employed to isolate spl11. five spl11-linked rapd markers were developed and four of them were mapped to rice chromosome 12. a high-resolution genetic map was developed using a segregating population consi ... | 2002 | 12395200 |
| rpff mutants of xanthomonas oryzae pv. oryzae are deficient for virulence and growth under low iron conditions. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. in the related bacterium xanthomonas campestris pv. campestris, the rpff gene is involved in production of a diffusible extracellular factor (dsf) that positively regulates synthesis of virulence-associated functions like extracellular polysaccharide (eps) and extracellular enzymes. transposon insertions in the rpff homolog of x. oryzae pv. oryzae are deficient for virulence and production of a dsf but are pro ... | 2002 | 12036277 |
| dna markers and marker-assisted breeding for durable resistance to bacterial blight disease in rice. | bacterial leaf blight caused by the bacterial pathogen xanthomonas oryzae pv oryzae (xoo) limits rice yield in all major rice-growing regions of the world, especially in irrigated lowland and rainfed conditions where predisposition factors favor disease development to epidemic proportions. since bacterial pathogens are difficult to manage, development of host plant resistance is the most effective means of disease management. as many as 24 major genes conferring resistance to various races of th ... | 2002 | 14538061 |
| two novel type iii-secreted proteins of xanthomonas campestris pv. vesicatoria are encoded within the hrp pathogenicity island. | the hrp type iii protein secretion system (ttss) is essential for pathogenicity of gram-negative plant pathogen xanthomonas campestris pv. vesicatoria. cdna-amplified fragment length polymorphism and reverse transcription-pcr analyses identified new genes, regulated by key hrp regulator hrpg, in the regions flanking the hrp gene cluster. sequence analysis revealed genes encoding hpag, a predicted leucine-rich repeat-containing protein, the lysozyme-like hpah protein, and xopa and xopd, which are ... | 2002 | 11844763 |
| a high-molecular-weight outer membrane protein of xanthomonas oryzae pv. oryzae exhibits similarity to non-fimbrial adhesins of animal pathogenic bacteria and is required for optimum virulence. | transposon insertions in a novel 3.798 kb open reading frame (orf) of the rice pathogen, xanthomonas oryzae pv. oryzae (xoo) cause virulence deficiency and altered colony/lawn morphology. this orf encodes a protein, xada, of 1,265 amino acids that exhibits significant similarity to non-fimbrial adhesins of animal pathogenic bacteria such as yersinia yada and moraxella uspa1. an interesting feature is that the yada similarity region is repeated six times within the xada sequence and encompasses a ... | 2002 | 12410822 |
| molecular determinants of disease and resistance in interactions of xanthomonas oryzae pv. oryzae and rice. | xanthomonas oryzae pv. oryzae is the causal agent of rice bacterial blight disease. numerous genes critical for virulence have been identified. this article reviews current knowledge on the molecular mechanisms of x. oryzae pv. oryzae virulence. | 2002 | 12443901 |
| pyramiding transgenes for multiple resistance in rice against bacterial blight, yellow stem borer and sheath blight. | here we describe the development of transgene-pyramided stable elite rice lines resistant to disease and insect pests by conventional crossing of two transgenic parental lines transformed independently with different genes. the xa21 gene (resistance to bacterial blight), the bt fusion gene (for insect resistance) and the chitinase gene (for tolerance of sheath blight) were combined in a single rice line by reciprocal crossing of two transgenic homozygous ir72 lines. f4 plant lines carrying all t ... | 2002 | 12582865 |
| new gene for bacterial blight resistance in rice located on chromosome 12 identified from minghui 63, an elite restorer line. | abstract bacterial blight, caused by xanthomonas oryzae pv. oryzae, is a serious disease of rice worldwide. a new dominant gene for bacterial blight resistance in rice, xa25(t), was identified from minghui 63, a restorer line for a number of rice hybrids that are widely cultivated in china. this gene conferred resistance to philippine race 9 (pxo339) of x. oryzae pv. oryzae in both seedling and adult stages. it was mapped to the centromeric region of chromosome 12, 2.5 cm from a disease resistan ... | 2002 | 18943271 |
| the defense-responsive genes showing enhanced and repressed expression after pathogen infection in rice (oryza sativa l.). | despite large numbers of studies about defense response, processes involved in the resistance of plants to incompatible pathogens are still largely uncharacterized. the objective of this study was to identify genes involved in defense response by cdna array analysis and to gain knowledge about the functions of the genes involved in defense response. approximately 20000 rice cdna clones were arrayed on nylon filters. rna samples isolated from different rice lines after infection with incompatible ... | 2002 | 18759033 |
| inheritance of resistance to bacterial blight in 21 cultivars of rice. | abstract genetic analysis for resistance to bacterial blight (xanthomonas oryzae pv. oryzae) of 21 rice (oryza sativa l.) cultivars was carried out. these cultivars were divided into two groups based on their reactions to philippine races of bacterial blight. cultivars of group 1 were resistant to race 1 and those of group 2 were susceptible to race 1 but resistant to race 2. all the cultivars were crossed with tn1, which is susceptible to all the philippine races of x. oryzae pv. oryzae. f(1) a ... | 2003 | 18943128 |
| localizing the bacterial blight resistance gene, xa22(t), to a 100-kilobase bacterial artificial chromosome. | abstract the rice bacterial blight resistance gene, xa22(t), provides resistance to a broad spectrum of xanthomonas oryzae pv. oryzae isolates. here, we localize the gene to a small 100-kb fragment of chromosome 11 by a combination of genetic recombination analysis and physical mapping. mapping was done with two f(2) populations from the cross between zhachanglong and zhenzhuai. the first population consisted of 248 random individuals and 404 highly susceptible individuals selected from an f(2) ... | 2003 | 18944325 |
| antagonistic interactions between strains of xanthomonas oryzae pv. oryzae. | abstract the ability of some phytopathogenic bacterial strains to inhibit the growth of others in mixed infections has been well documented. here we report that such antagonistic interactions occur between several wild-type strains of the rice bacterial blight pathogen xanthomonas oryzae pv. oryzae. in mixed inoculations, a wild-type philippine strain was found to inhibit the growth of a wild-type korean strain. furthermore, a nonpathogenic mutant of the philippine strain maintained these antago ... | 2003 | 18943057 |
| identification of a 47-kb dna fragment containing xa4, a locus for bacterial blight resistance in rice. | bacterial blight caused by xanthomonas oryzae pv oryzae is a devastating disease in rice worldwide. the resistance gene xa4 has been widely used in breeding programs and played an important role in protecting rice from this disease. using 642 highly susceptible individuals and a random sample of 255 individuals from an f(2) population developed from a cross between irbb4 and ir24, the xa4 gene was genetically mapped to a region less than 1 cm. a contig map was constructed for the xa4 region cons ... | 2003 | 12595998 |
| brassinosteroid functions in a broad range of disease resistance in tobacco and rice. | brassinolide (bl), considered to be the most important brassinosteroid (br) and playing pivotal roles in the hormonal regulation of plant growth and development, was found to induce disease resistance in plants. to study the potentialities of bl activity on stress responding systems, we analyzed its ability to induce disease resistance in tobacco and rice plants. wild-type tobacco treated with bl exhibited enhanced resistance to the viral pathogen tobacco mosaic virus (tmv), the bacterial pathog ... | 2003 | 12609030 |
| three types of defense-responsive genes are involved in resistance to bacterial blight and fungal blast diseases in rice. | bacterial blight and fungal blast diseases of rice, caused by xanthomonas oryzae pv. oryzae and pyricularia grisea sacc., respectively, are two of the most devastating diseases in rice worldwide. to study the defense responses to infection with each of these pathogens, expression profiling of 12 defense-responsive genes was performed using near-isogenic rice lines that are resistant or susceptible to bacterial blight and fungal blast, respectively, and rice cultivars that are resistant or suscep ... | 2003 | 12684879 |
| compositional difference of the exopolysaccharides produced by the virulent and virulence-deficient strains of xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae, the bacterial blight pathogen of rice, is known to produce phytotoxic polysaccharides. the extracellular polysaccharide (eps) was isolated from virulent (bxo1) and virulence-deficient gum g mutant (bxo1002) strains of x. oryzae pv. oryzae and characterized using fourier transform infrared (ft-ir) and nuclear magnetic resonance (nmr). data from the ft-ir suggested that the aldehyde (r-cho) group and c=o of acid anhydride are present in bxo1 but absent in bxo1002. th ... | 2003 | 12732972 |
| genetic and physical mapping of a new gene for bacterial blight resistance in rice. | the inheritance of resistance for bacterial blight, caused by xanthomonas oryzae pv. oryzae ( xoo), was studied in minghui 63, an elite restorer line for a number of widely used rice hybrids in china. a new dominant gene against a chinese xoo strain jl691 in both the seedling and adult stages was identified in minghui 63 and designated as xa26( t). using a total of 477 highly susceptible individuals from an f(2) population, the xa26( t) locus was mapped to a region of about 1.68 cm. this locus c ... | 2003 | 12750790 |
| high-quality mutant libraries of xanthomonas oryzae pv. oryzae and x. campestris pv. campestris generated by an efficient transposon mutagenesis system. | a novel transposon mutagenesis system for the phytopathogenic bacteria xanthomonas oryzae pv. oryzae (xoo) and x. campestris pv. campestris (xcc) was developed using a tn5-based transposome. a highly efficient transformation up to 10(6) transformants per microg transposon dna was obtained. southern blot and thermal asymmetric interlaced polymerase chain reaction analyses of tn5 insertion sites suggested a random mode of transposition. the transposition was stable in the transformants for 20 subc ... | 2003 | 13129620 |
| [accelerated improvement of bacterial blight resistance of 'shuhui527' using molecular marker-assisted selection]. | 'shuhui527' is a promising restorer line bred by rice research institute of sichuan agricultural university in recent years. however, this line is susceptible to bacterial blight (bb), which limits its use. the irbb60, from the international rice research institute (irri), contains dominant genes xa21 and xa4 conferring resistance to bb. the objective of this study is to improve the bb resistance of 'shuhui527' by introgressing xa21 and xa4, the two broad-spectrum bb resistance genes, into 'shuh ... | 2003 | 15966313 |
| phya, a secreted protein of xanthomonas oryzae pv. oryzae, is required for optimum virulence and growth on phytic acid as a sole phosphate source. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. we have identified a novel virulence deficient mutant (bxo1691) of x. oryzae pv. oryzae that has a tn5 insertion in an open reading frame (phya; putative phytase a) encoding a 373-amino acid (aa) protein containing a 28-aa predicted signal peptide. extracellular protein profiles revealed that a 38-kda band is absent in phya mutants as compared with phya+ strains. a blast search with phya and its deduced polype ... | 2003 | 14601665 |
| [detection and identification of xanthomonas oryzae pv. oryzae and xanthomonas oryzae pv. oryzicola by real-time fluorescent pcr]. | a novel and sensitive real time pcr was developed to detection xanthomonas oryzae pv. oryzae and xanthomonas oryzae pv. oryzicola, which cause the bacteria leaf blight (blb) and leaf streak respectively, universal and specific taqman probes, which were designed based on the sequence of putative siderophore receptor gene cds were used to detect 13 bacteria and one phytoplasmas, only in x. oryzae pv. oryzae and x. oryzae pv. oryzicola, fluorescent signal can be collected with their specific probes ... | 2003 | 16281561 |