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production of antimicrobial defensin in nicotiana benthamiana with a potato virus x vector.a recombinant plasmid, ptxs.th, was constructed to express the gene-encoding wasabi (wasabia japonica) defensin with the potato virus x (pvx) vector. ptxs.th allows the expression of defensin in the host nicotiana benthamiana, and the defensin protein wt1 can be purified from virus-infected leaves by heat treatment and affinity chromatography. wt1 exhibits strong antifungal activity toward the phytopathogenic fungi magnaporthe grisea (50% inhibitory concentration [ic50] = 5 microg/ml) and botryt ...200111204773
conversion of pipecolic acid into lysine in penicillium chrysogenum requires pipecolate oxidase and saccharopine reductase: characterization of the lys7 gene encoding saccharopine reductase.pipecolic acid is a component of several secondary metabolites in plants and fungi. this compound is useful as a precursor of nonribosomal peptides with novel pharmacological activities. in penicillium chrysogenum pipecolic acid is converted into lysine and complements the lysine requirement of three different lysine auxotrophs with mutations in the lys1, lys2, or lys3 genes allowing a slow growth of these auxotrophs. we have isolated two p. chrysogenum mutants, named 7.2 and 10.25, that are una ...200111717275
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 ...200111387980
the role of g protein alpha subunits in the infection process of the gray mold fungus botrytis cinerea.to identify signal transduction pathways of the gray mold fungus botrytis cinerea involved in host infection, we used heterologous hybridization and a polymerase chain reaction (pcr)-based approach to isolate two genes (bcg1 and bcg2) encoding alpha subunits of heterotrimeric gtp-binding proteins. both genes have homologues in other fungi: bcg1 is a member of the g alpha(i) class, whereas bcg2 has similarities to the magc gene of magnaporthe grisea and the gna-2 gene of neurospora crassa. revers ...200111763127
heat shock, copper sulfate and oxidative stress activate the retrotransposon maggy resident in the plant pathogenic fungus magnaporthe grisea.maggy is a gypsy-like retrotransposon isolated from the plant pathogenic fungus magnaporthe grisea. the ability of various stresses to activate maggy was tested in the original and in a heterologous host (colletotrichum lagenarium), using beta-glucuronidase (gus) as a reporter. the maggy promoter was activated in m. grisea by either heat shock, copper sulfate, or oxidative stress, but not by the antifungal substance p-coumaric acid. transcriptional up-regulation of maggy rna was also observed fo ...200111683275
probenazole induces systemic acquired resistance in arabidopsis with a novel type of action.probenazole (pbz; 3-allyloxy-1,2-benzisothiazole-1,1-dioxide), which is the active ingredient in oryzemate, has been used widely in asia to protect rice plants against the rice blast fungus magnaporthe grisea. to study pbz's mode of action, we analyzed its ability, as well as that of its active metabolite 1, 2-benzisothiazol-3 (2h)-one 1,1-dioxide (bit) to induce defense gene expression and resistance in arabidopsis mutants that are defective in various defense signaling pathways. wild-type arab ...200111169191
molecular cloning, sequence analysis and expression of a novel gene induced by near-uv light in bipolaris oryzae.a cdna clone derived from a novel gene (uvi-1) that is inducible by near-uv light was isolated by a differential screening procedure from a cdna library of the fungus bipolaris oryzae and characterized further. sequence analysis of the clone revealed that uvi-1 encodes a protein with a putative molecular mass of 17 kda; the uvi-1 protein shows significant similarity to a putative protein encoded by a cdna which is expressed during appressorium formation in the rice blast fungus, magnaporthe gris ...200111589579
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 ...200120573024
utility of cytoplasmic fluorescent proteins for live-cell imaging of magnaporthe grisea in planta.the subcellular expression patterns and fluorescence intensities of cytoplasm-targeted, constitutively expressed blue-, cyano-, green-, yellow- and red-fluorescent protein were assessed in a number of transformants of the blast pathogen, magnaporthe grisea. all transformants grew normally, remained pathogenic on barley, and, except for those expressing blue fluorescent protein, exhibited significant cytoplasmic fluorescence. the exceptionally intense brightness of some strains proved very useful ...200221156498
time for a blast: genomics of magnaporthe grisea.summary the rice blast fungus magnaporthe grisea causes one of the most destructive diseases of rice. genetic studies of this important pathogen during the past decade have made it an excellent system for investigating fungal-plant interactions. recently, the well coordinated efforts by the rice blast community have also made significant progresses in genomics studies of m. grisea. bac contigs were assembled and integrated with the high density genetic map, and 12 674 bac-ends were sequenced as ...200220569324
development of new fungicides against magnaporthe grisea: synthesis and biological activity of pyrazolo[3,4-d][1,3]thiazine, pyrazolo[1,5-c][1,3,5]thiadiazine, and pyrazolo[3,4-d]pyrimidine derivatives.some pyrazolo[3,4-d]pyrimidin-4(5h)-thione, pyrazolo[3,4-d][1,3]thiazin-4-one/thione, and pyrazolo[1,5-c][1,3,5]thiadiazine-4-one/thione derivatives were synthesized and screened for antifungal activity against the causal agent of rice blast disease, magnaporthe grisea. in all cases a remarkable inhibition of fungal growth was found in the range from 10 to 200 microg x ml(-1). several compounds were able to control mycelium growth at a rate of 10 microg x ml(-1), a concentration at which the ref ...200212166969
the biotrophic, non-appressorium-forming grass pathogen claviceps purpurea needs a fus3/pmk1 homologous mitogen-activated protein kinase for colonization of rye ovarian tissue.claviceps purpurea is a common pathogen of a wide range of grasses and cereals that is able to establish a stable, balanced interaction with its host plant and is considered a biotroph. it does not form special penetration structures such as appressoria. to study the signaling processes involved in this special host-pathogen interaction, we have cloned a gene, cpmk1, encoding a mitogen-activated protein (map) kinase that shows significant homology to fus3 of saccharomyces cerevisiae and to pmk1 ...200212026168
genomics of phytopathogenic fungi and the development of bioinformatic resources.genomic resources available to researchers studying phytopathogenic fungi are limited. here, we briefly review the genomic and bioinformatic resources available and the current status of fungal genomics. we also describe a relational database containing sequences of expressed sequence tags (ests) from three phytopathogenic fungi, blumeria graminis, magnaporthe grisea, and mycosphaerella graminicola, and the methods and underlying principles required for its construction. the database contains si ...200212036272
a novel gene, cbp1, encoding a putative extracellular chitin-binding protein, may play an important role in the hydrophobic surface sensing of magnaporthe grisea during appressorium differentiation.the conidial germ tube of the rice blast fungus, magnaporthe grisea, differentiates a specialized cell, an appressorium, required for penetration into the host plant. formation of the appressorium is also observed on artificial solid substrata such as polycarbonate. a novel emerging germ tube-specific gene, cbp1 (chitin-binding protein), was found in a cdna subtractive differential library. cbp1 coded for a putative extracellular protein (signal peptide) with two similar chitin-binding domains a ...200212036274
disruption of the alternative oxidase gene in magnaporthe grisea and its impact on host infection.plants and numerous fungi including magnaporthe grisea protect mitochondria from interference by respiration inhibitors by expressing alternative oxidase, the enzymatic core of alternative respiration. the alternative oxidase gene aoxmg of m. grisea was disrupted. several lines of evidence suggested that the disruption of aoxmg was sufficient to completely curb the expression of alternative respiration. in the infection of barley leaves, several aoxmg-minus and, thus, alternative respiration-def ...200212036280
a second reductase gene involved in melanin biosynthesis in the sap-staining fungus ophiostoma floccosum.two different dna sequences amplified by pcr from ophiostoma floccosum show high homology to reductase genes of the fungal melanin biosynthetic pathway and suggest that two reductases may participate in this pathway in o. floccosum. previously, one reductase gene, thn1 had been isolated from o. floccosum and proved to be involved in melanin biosynthesis. the second reductase gene, thn2, encodes a protein of 284 amino acids and is the longest fungal melanin reductase so far reported. the protein ...200212172794
analysis of the structure of the avr1-co39 avirulence locus in virulent rice-infecting isolates of magnaporthe grisea.the avr1-co39 gene that came from a magnaporthe grisea isolate from weeping lovegrass controls avirulence on the rice cultivar co39. avr1-co39 was not present in the genome of the rice-infecting m. grisea isolate guyll from french guyana, suggesting that the gene had been deleted. molecular analysis of the deletion breakpoints in the avr1-co39 locus revealed the presence of a truncated copy of a previously unknown retrotransposon at the left-hand border. at the right-hand border was a truncated ...200211843304
effects of signaling molecules, protein phosphatase inhibitors and blast pathogen (magnaporthe grisea) on the mrna level of a rice (oryza sativa l.) phospholipid hydroperoxide glutathione peroxidase (osphgpx) gene in seedling leaves.with a specific focus on rice self-defense response(s), the effects of global signaling molecules, jasmonic acid (ja), salicylic acid (sa), abscisic acid (aba), and ethylene (using the ethylene generator, ethephon), and protein phosphatase (pp) inhibitors, cantharidin and endothall on expression of a rice phospholipid hydroperoxide glutathione peroxidase (osphgpx) gene in rice seedling leaves were investigated. we provide first evidence for a potent up-regulation of the osphgpx mrna accumulation ...200211867229
engineering a genetic transformation system for colletotrichum acutatum, the causal fungus of lime anthracnose and postbloom fruit drop of citrus.postbloom fruit drop (pfd) of citrus is caused by colletotrichum acutatum. pfd isolates infect flower petals, induce abscission of small fruit and can cause severe yield loss on most citrus cultivars. isolates from key lime anthracnose (kla) cause that disease on the mexican lime, but also cause pfd on sweet orange. both pfd and kla isolates exhibited resistance to the common selection agents including hygromycin, bialaphos, benomyl and geneticin/g418. a genetic transformation system was develop ...200212127485
genetic and physical mapping of a rice blast resistance locus, pi-co39(t), that corresponds to the avirulence gene avr1-co39 of magnaporthe grisea.we have identified, genetically mapped and physically delineated the chromosomal location of a new rice blast resistance locus, designated pi-co39(t). this locus confers resistance to magnaporthe grisea isolates carrying the avr1-co39 avirulence locus. the avr1-co39 locus is conserved in non-rice (cereals and grasses)-infecting isolates of m. grisea, making pi-co39(t) useful for engineering m. grisea resistance in rice and other cereals. the resistance in the rice line co39 was inherited as a si ...200212172799
characterization of a novel rice gene osatx and modulation of its expression by components of the stress signalling pathways.in our search to identify gene(s) involved in the rice self-defense responses, we cloned a novel rice (oryza sativa l. cv. nipponbare) gene, osatx, a single copy gene, from the ja treated rice seedling leaves cdna library. this gene encodes a 69 amino acid polypeptide with a predicted molecular mass of 7649.7 and a pi of 5.6. osatx was responsive to cutting (wounding by cutting the excised leaf), over its weak constitutive expression in the healthy leaves. the critical signalling molecules, jasm ...200212207666
repeat-induced point mutation (rip) in magnaporthe grisea: implications for its sexual cycle in the natural field context.repeat-induced point mutation (rip) is a process that detects dna duplications and peppers their sequences with c:g to t:a transitions in the sexual phase of the life cycle. so far, this unique mechanism has been identified as a currently active process in only two fungal species, neurospora crassa and podospora anserina. to determine whether a rip-like process operates in the plant pathogenic fungus magnaporthe grisea, the retrotransposon maggy and the hygromycin b phosphotransferase gene were ...200212207702
efficient gene identification and targeted gene disruption in the wheat blotch fungus mycosphaerella graminicola using tagko.tagko ( transposon- arrayed gene knock out) is a highly efficient method for gene discovery and gene function assignment in the rice blast fungus magnaporthe grisea. here, we report the application of genome-wide tagko to the wheat blotch fungus mycosphaerella graminicola, including the successful development of electroporation-based transformation for this fungus. a m. graminicola genomic cosmid library was constructed and a pool of 250 cosmid clones was mutagenized by in vitro transposition. s ...200212478391
fungal melanin inhibitor and related compounds from penicillium decumbens.two polyketides, decumbenones a and b, and versiol were isolated from the culture filtrate of the fungus, penicillium decumbens. their respective structures were 1-(2,8-dihydroxy-1,2,6-trimethyl-1,2,6,7,8,8a-hexahydronaphthalen-1-yl)-3-hydroxy-1-propanone and 1-(2,8-dihydroxy-1,2,6-trimethyl-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)-3-hydroxy-1-propanone based on nmr spectroscopic data, chemical conversion, and x-ray analysis. decumbenone a inhibited melanization in magnaporthe grisea, the ric ...200212127587
regulation of the mpg1 hydrophobin gene in the rice blast fungus magnaporthe grisea.the hydrophobin-encoding gene mpg1 of the rice blast fungus magnaporthe grisea is highly expressed during the initial stages of host plant infection and targeted deletion of the gene results in a mutant strain that is reduced in virulence, conidiation, and appressorium formation. the green fluorescent protein-encoding allele sgfp was used as a reporter to investigate regulatory genes that control mpg1 expression. the map kinase-encoding gene pmk1 and the wide domain regulators of nitrogen source ...200212481998
molecular characterization of a cystathionine beta-synthase gene, cbs1, in magnaporthe grisea.cbs1 from magnaporthe grisea is a structural and functional homolog of the cystathionine beta-synthase (cbs) gene from saccharomyces cerevisiae. our studies indicated that m. grisea can utilize homocysteine and methionine through a cbs-independent pathway. the results also revealed responses of m. grisea to homocysteine that are reminiscent of human homocystinuria.200212455965
the mitogen-activated protein kinase gene maf1 is essential for the early differentiation phase of appressorium formation in colletotrichum lagenarium.colletotrichum lagenarium, the causal agent of cucumber anthracnose, invades host plants by forming a specialized infection structure called an appressorium. in this fungus, the mitogen-activated protein kinase (mapk) gene cmk1 is involved in several steps of the infection process, including appressorium formation. in this study, the goal was to investigate roles of other mapks in c. lagenarium. the mapk gene maf1, related to saccharomyces cerevisiae mpk1 and magnaporthe grisea mps1, was isolate ...200212481999
magnaporthedb: a federated solution for integrating physical and genetic map data with bac end derived sequences for the rice blast fungus magnaporthe grisea.we have created a federated database for genome studies of magnaporthe grisea, the causal agent of rice blast disease, by integrating end sequence data from bac clones, genetic marker data and bac contig assembly data. a library of 9216 bac clones providing >25-fold coverage of the entire genome was end sequenced and fingerprinted by hindiii digestion. the image/fpc software package was then used to generate an assembly of 188 contigs covering >95% of the genome. the database contains the result ...200211752272
diversity of antifungal actinomycetes in various vegetative soils of korea.diversity of actinomycetes and their antifungal activities against some plant pathogenic fungi were examined in various vegetative soils from 14 different sites in the western part of korea. actinomycete counts ranged from 1.17 x 10(6) to 4.20 x 10(6) cfu x g(-1) dried soil. a total of 1510 actinomycetes were isolated from the soil samples. streptomyces was predominant in soils with a ph range of 5.1-6.5, 9.1-13.0% moisture, and 9.1-11.0% organic matter. most micromonospora, dactylosporangium, a ...200212109880
meiotic deletion at the buf1 locus of the fungus magnaporthe grisea is controlled by interaction with the homologous chromosome.the magnaporthe grisea buf1 gene suffers high-frequency mutation in certain genetic crosses, resulting in buff-colored progeny. analysis of 16 buf1 mutants arising from a cross with a mutation frequency of 25% revealed that, in every case, the buf1 gene was deleted. the deletions occurred in only one of the parental chromosomes and were due to intrachromosomal recombination. tetrad analysis revealed that deletions occurred in 44% of meioses and usually affected both chromatids of the mutable chr ...200211805051
structural definition of the active site and catalytic mechanism of 3,4-dihydroxy-2-butanone-4-phosphate synthase.x-ray crystal structures of l-3,4-dihydroxy-2-butanone-4-phosphate synthase from magnaporthe grisea are reported for the e-so(4)(2-), e-so(4)(2-)-mg(2+), e-so(4)(2)(-)-mn(2+), e-so(4)(2)(-)-mn(2+)-glycerol, and e-so(4)(2)(-)-zn(2+) complexes with resolutions that extend to 1.55, 0.98, 1.60, 1.16, and 1.00 a, respectively. active-site residues of the homodimer are fully defined. the structures were used to model the substrate ribulose 5-phosphate in the active site with the phosphate group anchor ...200211827524
identification of a putative vacuolar serine protease gene in the rice blast fungus, magnaporthe grisea.we identified and cloned a gene designated spm1, encoding a serine protease from the rice blast fungus magnaporthe grisea. spm1 is a single-copy gene, encoding a subtilisin-like serine protease with 536 amino acids. analyses of the deduced amino acid sequence of spm1 suggested that spm1 would be localized in a vacuole, an important organelle in pathogenicity.200212005067
inducibility by pathogen attack and developmental regulation of the rice ltp1 gene.using a genomic clone encoding a rice lipid transfer protein, ltp1, we analysed the activity of the 5' region of the ltp1 gene in transgenic rice (oryza sativa l.) during plant development and under pathogen attack. the -1176/+13, -556/+13 and -284/+13 regions of the promoter were fused upstream from the uida reporter gene and nos 3' polyadenylation signal, resulting in the pdelta1176gus, pdelta556gus and pdelta284gus constructs which were transferred to rice by microprojectile bombardment. hist ...200212081375
an atp-binding cassette multidrug-resistance transporter is necessary for tolerance of gibberella pulicaris to phytoalexins and virulence on potato tubers.the necrotrophic pathogen gibberella pulicaris infects potato tubers through wounds that contain fungitoxic secondary metabolites such as the phytoalexins rishitin and lubimin. in order to colonize tuber tissue, the fungus must possess a mechanism to tolerate potato defense compounds. in this paper, we show that a gene, gpabc1, that codes an atp-binding cassette (abc) transporter is required for tolerance to these phytoalexins and for virulence on potato. the gpabc1 gene, isolated in the course ...200211876422
a microsatellite sequence from the rice blast fungus (magnaporthe grisea) distinguishes between the centromeres of hordeum vulgare and h. bulbosum in hybrid plants.a tc/ag-repeat microsatellite sequence derived from the rice blast fungus (magnaporthe grisea) hybridized to all of the centromeres of hordeum vulgare chromosomes, but hybridized faintly or not at all to the chromosomes of hordeum bulbosum. using this h. vulgare centromere-specific probe, the chromosomes of four f1 hybrids between h. vulgare and h. bulbosum were analyzed. the chromosome constitution in the root tips of the hybrids was mosaic, i.e., 7 (7v, h. vulgare) and 14 (7v + 7b h. bulbosum) ...200211908659
mst12 regulates infectious growth but not appressorium formation in the rice blast fungus magnaporthe grisea.in the rice blast fungus magnaporthe grisea, a mitogen-activated protein kinase gene, pmk1, is known to regulate appressorium formation and infectious hyphae growth. since pmk1 is homologous to the fus3 and kss1 genes that regulate the transcription factor ste12 in yeast, we functionally characterized the ste12 homologue in m. grisea (mst12). a polymerase chain reaction-based approach was used to isolate the mst12 gene that is homologous to yeast ste12. four mst12 deletion mutants were isolated ...200211952120
a magnaporthe grisea cyclophilin acts as a virulence determinant during plant infection.cyclophilins are peptidyl prolyl cis-trans isomerases that are highly conserved throughout eukaryotes and that are best known for being the cellular target of the immunosuppressive drug cyclosporin a (csa). the activity of csa is caused by the drug forming a complex with cyclophilin a and inhibiting the calmodulin-dependent phosphoprotein phosphatase calcineurin. we have investigated the role of cyp1, a cyclophilin-encoding gene in the phytopathogenic fungus magnaporthe grisea, which is the caus ...200211971145
osbimk1, a rice map kinase gene involved in disease resistance responses.the activation of mitogen-activated protein kinases (mapks) has been previously implicated in signal transduction during plant responses to pathogen attack as well as to various environmental stresses. we have isolated from rice a new mapk cdna, osbimk1 ( o ryza s ativa l. bth-induced mapk 1), which encodes a 369-amino-acid protein with moderate to high nucleotide sequence similarity to previously reported plant mapk genes. osbimk1 contains all 11 of the mapk conserved subdomains and the phospho ...200212355160
identification of a 118-kb dna fragment containing the locus of blast resistance gene pi-2(t) in rice.rice blast disease, caused by the fungal pathogen pyricularia grisea sacc., is one of the most devastating crop diseases worldwide. previous studies have shown that the dominant blast resistance gene pi-2(t) confers resistance to a broad spectrum of pathogenic strains. using a population of 292 recombinant inbred lines combined with bioinformatic analysis, we mapped pi-2(t) between the ssr (simple-sequence repeat) marker ssr140 and the rflp (restriction fragment length polymorphism) marker jsh12 ...200212395199
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 ...200212395200
development of novel pesticides based on phytoalexins: part 2. quantitative structure-activity relationships of 2-heteroaryl-4-chromanone derivatives.phytoalexins are low-molecular-weight chemicals that immune systems of plants produce and accumulate in response to infections, especially those of fungal origin. although their content is not high in plants, yet they have shown unique fungicidal activity and played an important role in the defence system of plants. in searching for novel environmentally benign fungicides with high activity, the structures of flavanone derivatives, one of the most important phytoalexins groups, have been modifie ...200212400447
a mitogen-activated protein kinase gene (mgv1) in fusarium graminearum is required for female fertility, heterokaryon formation, and plant infection.fusarium graminearum is an important pathogen of small grains and maize in many areas of the world. infected grains are often contaminated with mycotoxins harmful to humans and animals. during the past decade, f. graminearum has caused several severe epidemics of head scab in wheat and barley. in order to understand molecular mechanisms regulating fungal development and pathogenicity in this pathogen, we isolated and characterized a map kinase gene, mgv1, which is highly homologous to the mps1 g ...200212423017
reef coral fluorescent proteins for visualizing fungal pathogens.the fluorescent proteins amcyan, zsgreen, zsyellow, and asred, modified versions of proteins identified recently from several anthozoa species of reef corals, were expressed for the first time in a heterologous system and used for imaging two different fungal plant pathogens. when driven by strong constitutive fungal promotors, expression of these reef coral fluorescent proteins yielded bright cytoplasmic fluorescence in fusarium verticillioides and magnaporthe grisea, and had no detectable effe ...200212431456
live-cell imaging of endocytosis during conidial germination in the rice blast fungus, magnaporthe grisea.although there is growing evidence that endocytosis is important in hyphal tip growth, it has not previously been shown to occur during fungal spore germination. we have analysed and characterized endocytosis during the germination of living conidia of the rice blast fungus, magnaporthe grisea. conidia treated with the endocytic markers lucifer yellow carbohydrazide, fitc-dextran, and fm4-64 were imaged by confocal microscopy. internalization of these fluorescent marker dyes by conidia was block ...200212431458
apoptotic cell death is a common response to pathogen attack in oats.we have examined the characteristics of cell death induced by pathogen infection in oats with respect to following hallmark apoptotic features: dna laddering, chromatin condensation, and electron microscopic-terminal deoxynucleotidyl transferase-mediated utp end labeling positive response. a wide range of plant pathogens representing different levels of parasitism in susceptible and resistant interactions were used for the inocula, which include (i) an obligate parasite, puccinia coronata f. sp. ...200212437297
cpmk2, an slt2-homologous mitogen-activated protein (map) kinase, is essential for pathogenesis of claviceps purpurea on rye: evidence for a second conserved pathogenesis-related map kinase cascade in phytopathogenic fungi.cpmk2, encoding a mitogen-activated protein (map) kinase from the ascomycete claviceps purpurea, is an orthologue of slt2 from saccharomyces cerevisiae, the first isolated from a biotrophic, non-appressorium-forming pathogen. deletion mutants obtained by a gene replacement approach show impaired vegetative properties (no conidiation) and a significantly reduced virulence, although they retain a limited ability to colonize the host tissue. increased sensitivity to protoplasting enzymes indicates ...200212406210
glycosphingolipids from magnaporthe grisea cells: expression of a ceramide dihexoside presenting phytosphingosine as the long-chain base.magnaporthe grisea is a fungal pathogen that infects rice leaves and causes rice blast, a devastating crop disease. m. grisea produces active elicitors of the hypersensitive response in rice that were previously identified as ceramide monohexosides (cmhs). using several chromatographic approaches, mass spectrometry, and nuclear magnetic resonance, we identified ceramide mono- and dihexosides (cdh) in purified lipid extracts from m. grisea cells. as described by other authors, cmh consists of a c ...200212220534
a new class of tetraspanins in fungi.tetraspanins are animal proteins involved in membrane complexes that are involved in cell adhesion, differentiation, and motility. the pls1 gene from rice blast fungus magnaporthe grisea encodes a protein (pls1p) structurally related to tetraspanins that is required for pathogenicity. in botrytis cinerea public sequences, we identified an est homologous to pls1. using degenerated oligonucleotides, we amplified sequences homologous to pls1 in fungi colletotrichum lindemuthianum and neurospora cra ...200212372414
[genetic analysis of blast resistance in japonica rice landrace heikezijing from taihu region].japonica rice landrace heikezijing (hkzj) from taihu region is highly resistant to several chinese and japanese differential strains of magnaporthe grisea. the f1, f2 and ril populations from the cross between the resistant variety heikezijing and the susceptible variety lijiangxintuanheigu (ljxthg) were inoculated by spray with two strains of ken 54-04 and hoku 1 in seedling stages. based on the r:s ratios of segregation in f1, f2 and ril populations it was showed that there were two independen ...200212561228
[genetic analysis and molecular marker of avr-pi1, avr-pi2 and avr-pi4a of magnaporthe grisea].the isolate 81278zb15 is a fertile strain of predominant virulence of magnaporthe grisea in fujian province, china. its rep-pcr (repetitive element-based polymerase chain reaction) dna fingerprint and virulence spectrum are different from those of guy11, a hermophrodite. ascospores of the cross 81278zb15 and guy11 were randomly isolated and their virulence was tested on co39 nils (near isogenic lines, c101lac pi-1, c101a51 pi-2, c104pkt pi-3, c101pkt pi-4a, c105ttp-4l-23 pi-4b and co39). the res ...200212561231
[analysis of gene expression profiles during host-magnaporthe grisea interactions in a pair of near isogenic lines of rice].a pair of near isogenic lines g205 and g71 were selected from recombinant inbred lines (ril) of zhong156 x gumei2. on the resistance locus pi-25(t), g205 had the resistant allele that was from gumei 2 while g71 had the susceptible allele that was from zhong156. for the genetic background, different alleles were detected on only 24 loci out of the 672 rflp or sslp loci surveyed. the expression profiles of g205 and g71 in response to magnaporthe grisea were investigated using cdna microarray conta ...200212561473
overexpression of the wasabi defensin gene confers enhanced resistance to blast fungus ( magnaporthe grisea) in transgenic rice.transgenic rice ( oryza sativa cv. sasanishiki) overexpressing the wasabi defensin gene, a plant defensin effective against the rice blast fungus, was generated by agrobacterium tumefaciens-mediated transformation. twenty-two t2 homozygous lines harboring the wasabi defensin gene were challenged by the blast fungus. transformants exhibited resistance to rice blast at various levels. the inheritance of the resistance over generations was investigated. t3 plants derived from two highly blast-resis ...200212582903
cloning and sequence analysis of a mitochondrial gene cluster encoding cytochrome c oxidase subunit iii from trichoderma pseudokoningii.a mitochondrial gene cluster encoding cytochrome c oxidase subunit iii (cox3), an orf (called orf250) similar to nadh dehydrogenase subunit vi (nd6), ten trna molecules, partial rrna small subunit and rrna large subunit from trichoderma pseudokoningii s38 was cloned and sequenced. these genes are tandemly clustered on the mitochondrial genome of trichoderma pseudokoningii s38. phylogenetic analysis showed that cytochrome c oxidase subunits iii exhibited high degree of similarity to sequences fro ...200212592707
[allelopathic potential of volatile oil from mikania micrantha].mikania micrantha, an exotic plant species, is an important weed in south china. the volatile oil of the weed species had significant biological activities on plants and their pathogens, particularly pyricularia grisea. the results showed that the seeding growth of 6 plant species decreased obviously when exposed to increasing concentration (200, 400, 800, 1600 mg.l-1) of the volatile oil. the fresh weight of all test plants decreased, and the emergence of all test plants delayed for 1-2 days un ...200212557680
evolution and organization of a highly dynamic, subtelomeric helicase gene family in the rice blast fungus magnaporthe grisea.sequence analysis of a 13-kb telomeric region in o-137, a rice pathogenic isolate of magnaporthe grisea, uncovered a novel gene, designated tlh1 (telomere-linked helicase 1). the tlh1 gene is a member of a gene family, and the sequences flanking this gene family have also been amplified. genetic mapping showed that most members of the tlh gene family are tightly linked to the telomeres. a physical mapping technique, termed reca-mediated achilles' heel cleavage, and cloning and sequencing of two ...200212242226
pcr based molecular technique for identification and discrimination of quarantined and non-quarantined tilletia sps.polymerase chain reaction (pcr) based rapd profiles, in conjunction with six primers, of karnal bunt of wheat and rice bunt exhibiting distinct polymorphic dna. a total of 84 rapd loci were observed on polyacrylamide gel for both tilletia sps. out of 84, 16 loci were found monomorphic, while other 68 loci were unique. usefulness of random primers was also checked with other seed borne fungal pathogens of wheat and rice. none of primers gave amplification with magnaporthe grisea, a causative agen ...200212693693
rice brown spot and susceptibility of some cultivars in north of iran.rice brown spot is one of the important diseases in the world including iran. 91 samples of the infected plants such as leaves and panicles were collected from different locations of guilan province, north of iran and the fungi isolated and studied for pathogenicity. three species of bipolaris (b. oryzae, bipolaris sp. and b. cf. victoriae) were isolated more than other species with serious effects on the plants respectively. reactions of 8 cultivars of rice, neda, nemat, sepeed-rood, bejar, kha ...200212701419
a gene-for-gene relationship underlying the species-specific parasitism of avena/triticum isolates of magnaporthe grisea on wheat cultivars.abstract to elucidate genetic mechanisms of the species-specific parasitism of magnaporthe grisea, a triticum isolate (pathogenic on wheat) was crossed with an avena isolate (pathogenic on oat), and resulting f(1) progeny were subjected to segregation analyses on wheat cvs. norin 4 and chinese spring. we found two fungal loci, pwt3 and pwt4, which are involved in the specific parasitism on wheat. pwt3 operated on both cultivars while pwt4 operated only on 'norin 4'. using the cultivar specificit ...200218944243
pyricularia grisea isolates causing gray leaf spot on perennial ryegrass (lolium perenne) in the united states: relationship to p. grisea isolates from other host plants.abstract gray leaf spot of perennial ryegrass (prg) (lolium perenne), caused by the fungus pyricularia grisea (teleomorph = magnaporthe grisea), has rapidly become the most destructive of all turf grass diseases in the united states. fungal isolates from infected prg were analyzed with several molecular markers to investigate their relationship to p. grisea strains found on other hosts. all of the molecular markers used in this study revealed that isolates from prg are very distantly related to ...200218943995
inhibition of fungal spore adhesion by zosteric acid as the basis for a novel, nontoxic crop protection technology.abstract to explore the potential for nontoxic crop protection technologies based on the inhibition of fungal spore adhesion, we have tested the effect of synthetic zosteric acid (p-(sulfo-oxy) cinnamic acid), a naturally occurring phenolic acid in eelgrass (zostera marina l.) plants, on spore adhesion and infection in two pathosystems: rice blast caused by magnaporthe grisea and bean anthracnose caused by colletotrichum lindemuthianum. we have shown that zosteric acid inhibits spore adhesion to ...200218942950
quantification of magnaporthe grisea during infection of rice plants using real-time polymerase chain reaction and northern blot/phosphoimaging analyses.abstract rice blast, caused by magnaporthe grisea, is a serious fungal disease of rice worldwide. currently, evaluation of the fungal pathogenicity and host resistance is mainly based on a disease rating or measurement of blast lesion number and size. however, these methods only provide visual estimation rather than accurate measurement of fungal growth in rice plants. in this study, dna-based real-time polymerase chain reaction (pcr) and rna-based northern blot/phosphoimaging analyses were eval ...200218942966
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 ...200218759033
[effects of ecological factors on infection process of pyricularia grisea].rice blast is one of the main rice diseases. in order to discuss the occurrence regularity and improve the veracity of forecasting, the effects of ecological factors on infecting process, such as rice growth period, cultivar resistance, temperature, precipitation, and fertilization of nitrogen, were studied quantitatively. the results showed that adhering conidia on leaves, or ratio of infection was negatively correlative with the growth period of rice. the latent period of pyricularia grisea wa ...200212216396
[optimization of t-dna insertional mutagenesis and analysis of mutants of magnaporthe grisea].the rice blast fungus magnaporthe grisea causes one of the most destructive diseases of rice around the world. significant progresses have been made recently in genomics studies of the fungus, opening new era of the functional genomics which requires to generate a large scale of gene knockout mutants. it has been demonstrated that t-dna insertional mutagenesis is a powerful tool of functional genomics not only for plants but also for fungi. in this paper, we optimized the conditions for t-dna in ...200315969057
field resistance to strobilurin (q(o)i) fungicides in pyricularia grisea caused by mutations in the mitochondrial cytochrome b gene.abstract gray leaf spot caused by pyricularia grisea is a highly destructive disease of perennial ryegrass turf. control of gray leaf spot is dependent on the use of preventative fungicide treatments. strobilurin-based (q(o)i) fungicides, which inhibit the cytochrome bc(1) respiratory complex, have proven to be very effective against gray leaf spot. however, in august 2000, disease was diagnosed in q(o)i-treated perennial ryegrass turf on golf courses in lexington, ky, champaign, il, and bloomin ...200318943171
diversity of pathotypes and dna fingerprint haplotypes in populations of magnaporthe grisea in korea over two decades.abstract using isolates collected over 2 decades, we determined the population structure and dynamics of the rice blast fungus, magnaporthe grisea, in korea at both the genotypic and phenotypic levels. pathotype analysis on 6,315 isolates collected from 328 rice cultivars from 1981 to 2000 revealed the presence of a total of 91 pathotypes. among these 91 patho-types, nine dominated, comprising 76.5% of the isolates. the expected number of pathotypes (corrected for sample size) increased signific ...200318944065
natural variation at the pi-ta rice blast resistance locus.abstract the resistance gene pi-ta protects rice crops against the fungal pathogen magnaporthe grisea expressing the avirulence gene avr-pita in a gene-for-gene manner. pi-ta, originally introgressed into japonica rice from indica origin, was previously isolated by positional cloning. in this study, we report the nucleotide sequence of a 5,113-base pair region containing a japonica susceptibility pi-ta allele, which has overall 99.6% nucleotide identity to the indica pi-ta allele conferring resi ...200318944075
analysis of host species specificity of magnaporthe grisea toward foxtail millet using a genetic cross between isolates from wheat and foxtail millet.abstract host species specificity of magnaporthe grisea toward foxtail millet was analyzed using f(1) cultures derived from a cross between a triticum isolate (pathogenic on wheat) and a setaria isolate (pathogenic on foxtail millet). on foxtail millet cvs. beni-awa and oke-awa, avirulent and virulent cultures segregated in a 1:1 ratio, suggesting that a single locus is involved in the specificity. this locus was designated as pfm1. on cv. ki-awa, two loci were involved and one of them was pfm1. ...200318944155
ultrastructural and cytochemical aspects of silicon-mediated rice blast resistance.abstract although exogenous application of silicon (si) confers efficient control of rice blast, the probable hypothesis underlying this phenomenon has been confined to that of a mechanical barrier resulting from si polymerization in planta. however, in this study, we provide the first cytological evidence that si-mediated resistance to magnaporthe grisea in rice correlates with specific leaf cell reaction that interfered with the development of the fungus. accumulation of an amorphous material ...200318942975
a temperature and leaf wetness duration-based model for prediction of gray leaf spot of perennial ryegrass turf.abstract gray leaf spot is a serious disease of perennial ryegrass (lolium perenne), causing severe epidemics in golf course fairways. the effects of temperature and leaf wetness duration on the development of gray leaf spot of perennial ryegrass turf were evaluated in controlled environment chambers. six-week-old legacy ii ryegrass plants were inoculated with an aqueous conidial suspension of pyricularia grisea (approximately 8 x 10(4) conidia per ml of water) and subjected to four different te ...200318944344
the glyoxylate cycle is required for temporal regulation of virulence by the plant pathogenic fungus magnaporthe grisea.we describe the isolation and characterization of icl1 from the rice blast fungus magnaporthe grisea, a gene that encodes isocitrate lyase, one of the principal enzymes of the glyoxylate cycle. icl1 shows elevated expression during development of infection structures and cuticle penetration, and a targeted gene replacement showed that the gene is required for full virulence by m. grisea. in particular, we found that the prepenetration stage of development, before entry into plant tissue, is affe ...200312622815
acquired resistance functions in mlo barley, which is hypersusceptible to magnaporthe grisea.barley plants carrying a mutation in the mlo (barley [hordeum vulgare l.] cultivar ingrid) locus conferring a durable resistance against powdery mildew are hypersusceptible to the rice blast fungus magnaporthe grisea. it has been speculated that a functional mlo gene is required for the expression of basic pathogen resistance and that the loss of mlo function mediating powdery mildew resistance is an exception for this particular disease. here, we report that the onset of acquired resistance (ar ...200312575744
the development of simple sequence repeat markers for magnaporthe grisea and their integration into an established genetic linkage map.although microsatellite or simple sequence repeat (ssr) markers have several advantages, few have been developed in fungi. the goal of this study was to identify and characterize ssr-containing loci in the filamentous ascomycete magnaporthe grisea, the causal agent of rice blast disease, and to add these markers to an integrated genetic map of this species [theor. appl. genet. 95 (1997) 20]. we have constructed and screened a microsatellite-enriched small-insert genomic library as well as exploi ...200314599888
cloning, sequencing, and characterization of the genetic region relevant to biosynthesis of the lipopeptides iturin a and surfactin in bacillus subtilis.bacillus subtilis b3 was found to produce lipopeptides iturins and fengycin that have activity against several plant pathogens such as fusarium graminearum, rhizoctonia solani, rhizoctonia cerealis, and pyricularia grisea. a 3642-bp genomic region of b. subtilis b3 comprising srfdb3, aspb3, lpab3, and yczeb3 genes that resulted in biosynthesis of surfactin in b. subtilis 168 was cloned, sequenced, and characterized. among them, the srfdb3 gene encodes thioesterase, which is required for biosynth ...200314629006
on the trail of a cereal killer: exploring the biology of magnaporthe grisea.the blast fungus magnaporthe grisea causes a serious disease on a wide variety of grasses including rice, wheat, and barley. rice blast is the most serious disease of cultivated rice and therefore poses a threat to the world's most important food security crop. here, i review recent progress toward understanding the molecular biology of plant infection by m. grisea, which involves development of a specialized cell, the appressorium. this dome-shaped cell generates enormous turgor pressure and ph ...200314527276
proteomic analysis of differentially expressed proteins induced by rice blast fungus and elicitor in suspension-cultured rice cells.we used two-dimensional electrophoresis (2-de) and other proteomic approaches to identify proteins expressed in suspension-cultured rice cells in response to the rice blast fungus, magnaporthe grisea. proteins were extracted from suspension-cultured cells at 24 and 48 h after rice blast fungus inoculation or treatment with elicitor or other signal molecules such as jasmonic acid (ja), salicylic acid, and h(2)o(2). the proteins were then polyethylene glycol fractionated before separation by 2-de. ...200314673787
[analysis of genetic structure of magnaporthe grisea in the fields of different rice varieties].the dna of 251 magnaporthe grisea isolates from shiping county, which originated from monoculture and mixture fields, was extracted and amplified by rep-pcr which primer was from palindromes pot2 of magnaporthe grisea. the result showed that all isolates were amplified 9-17 dna bands, the size was about from 400 bp to 23 kb, but mainly between 5-10 kb. 65% bands were polymorphism bands, and 35% were the same bands. genetic structures of magnaporthe grisea in the different rice varieties fields w ...200312924129
linoleate diol synthase of the rice blast fungus magnaporthe grisea.mycelia of two strains of magnaporthe grisea, guy 11 and th3, were incubated with linoleic acid, and the metabolites were isolated and identified by gc-ms and lc-ms. the two main metabolites were identified as 8-hydroxylinoleic and 7,8-dihydroxylinoleic acids, and the former was further oxidized by n-2 and by n-3 hydroxylation to 8,16- and 8,17-dihydroxylinoleic acids. lipoxygenase metabolites of linoleic acid could not be detected. the sequence of the genome of m. grisea has been released from ...200314870931
rice c2-domain proteins are induced and translocated to the plasma membrane in response to a fungal elicitor.hundreds of proteins involved in signaling pathways contain a ca(2+)-dependent membrane-binding motif called the c2-domain. however, no small c2-domain proteins consisting of a single c2-domain have been reported in animal cells. we have isolated two cdna clones, oserg1a and oserg1b, that encode two small c2-domain proteins of 156 and 159 amino acids, respectively, from a fungal elicitor-treated rice cdna library. the clones are believed to have originated from a single gene by alternative splic ...200314529272
[chemical composition of volatile oil from chromolaena odorata and its effect on plant, fungi and insect growth].the volatile oil from c. odorata had a significant effect on the growth of plants, fungi and insects. the result showed that the seedling growth of five test plants was obviously inhibited, in the order of ryegrass > chinese cabbage > radish > snap been > rice. the inhibitory effect of the oil at its middle concentration (800 mg.l-1) for pyricularia grisea was the strongest, the next was to phytophthora nicotianae, and the weakest was to fusarium axysporum. the inhibitory percentage was 61.40%, ...200312924132
importance of ascorbate peroxidases osapx1 and osapx2 in the rice pathogen response pathways and growth and reproduction revealed by their transcriptional profiling.we have identified and characterized two rice ascorbate peroxidase (osapx1 and osapx2) genes against diverse signals known to involve in defense/stress responses, using "2-week-old rice seedling in vitro model system". oryza sativa ascorbate peroxidase 1 and 2 (osapx1/2) share 83% similarity to each other at amino acid level and belong to a small gene family in the rice genome. osapx1/2 show a weak constitutive expression in leaves. their transcripts were up-regulated upon wounding (by cut), and ...200314644501
purification and characterization of laccase from the rice blast fungus, magnaporthe grisea.a 70-kda extracellular laccase was purified from the rice blast fungus magnaporthe grisea using gel filtration and ion exchange chromatography the procedure provided 282-fold purification with a specific enzyme activity of 225.91 u mg(-1) and a yield of 11.92%. the enzyme oxidized a wide range of substrates. the highest level of oxidation was detected with syringaldazine as the substrate. using syringaldazine as the substrate, the enzyme exhibited a ph optimum of 6 and temperature optimum of 30 ...200314568157
a simple protocol for isolation of fungal dna.genomic dna was isolated from as little as 2 mg dry biomass of magnaporthe grisea by microwave treatment within 30 s. the quantity of dna was good enough for pcr analysis and dot blot hybridization. this technique can be used for various studies, such as dna fingerprinting to study the population structure of the phytopathogen in different regions, and for a quick screening of m. grisea transformants.200314719830
family 19 chitinase of streptomyces griseus hut6037 increases plant resistance to the fungal disease.chitinase c (chic) is the first bacterial family 19 chitinase discovered in streptomyces griseus hut6037. in vitro, chic clearly inhibited hyphal extension of trichoderma reesei but a rice family 19 chitinase did not. in order to investigate the effects of chic as an increaser of plant resistance to fungal diseases, the chic gene was introduced into rice plants under the control of the increased camv 35s promoter and a signal sequence from the rice chitinase gene. transgenic plants were morpholo ...200312784627
identification and fine mapping of pi33, the rice resistance gene corresponding to the magnaporthe grisea avirulence gene ace1.rice blast disease is a major constraint for rice breeding. nevertheless, the genetic basis of resistance remains poorly understood for most rice varieties, and new resistance genes remain to be identified. we identified the resistance gene corresponding to the cloned avirulence gene ace1 using pairs of isogenic strains of magnaporthe grisea differing only by their ace1 allele. this resistance gene was mapped on the short arm of rice chromosome 8 using progenies from the crosses ir64 (resistant) ...200312838393
co-expression of a modified maize ribosome-inactivating protein and a rice basic chitinase gene in transgenic rice plants confers enhanced resistance to sheath blight.chitinases, beta-1,3-glucanases, and ribosome-inactivating proteins are reported to have antifungal activity in plants. with the aim of producing fungus-resistant transgenic plants, we co-expressed a modified maize ribosome-inactivating protein gene, mod1, and a rice basic chitinase gene, rch10, in transgenic rice plants. a construct containing mod1 and rch10 under the control of the rice rbcs and act1 promoters, respectively, was co-transformed with a plasmid containing the herbicide-resistance ...200312885168
the bacterial transposon tn7 causes premature polyadenylation of mrna in eukaryotic organisms: tagko mutagenesis in filamentous fungi.tagko is a tn7-based transposition system for genome wide mutagenesis in filamentous fungi. the effects of transposon insertion on the expression of tagko alleles were examined in magnaporthe grisea and mycosphaerella graminicola. northern analysis showed that stable, truncated transcripts were expressed in the tagko mutants. mapping of the 3'-ends of tagko cdnas revealed that they all contain tn7 end sequences, regardless of the transposon orientation. polyadenylation signals characteristic of ...200312907724
diagnosis of dehydratase inhibitors in melanin biosynthesis inhibitor (mbi-d) resistance by primer-introduced restriction enzyme analysis in scytalone dehydratase gene of magnaporthe grisea.we have established a simple diagnosis method for rice blast fungus resistant to mbi-d. this involves the preparation of pcr templates directly from the lesions in combination with primer-introduced restriction enzyme analysis pcr (pira-pcr).200312916764
molecular markers linked to the blast resistance gene pi-z in rice for use in marker-assisted selection.rice blast, caused by the fungal pathogen pyricularia grisea, is a serious disease affecting rice-growing regions around the world. current methods for identification of blast-resistant germplasm and progeny typically utilize phenotypic screening. however, phenotypic screens are influenced by environmental conditions and the presence of one resistance gene can sometimes phenotypically mask other genes conferring resistance to the same blast race. pi-z is a dominant gene located on the short arm ...200312955204
analysis of expressed sequence tags from gibberella zeae (anamorph fusarium graminearum).gibberella zeae is a broad host range pathogen that infects many crop plants, including wheat and barley, and causes head blight and rot diseases throughout the world. to better understand fungal development and pathogenicity, we have generated 7996 ests from three cdna libraries. two libraries were generated from carbon-(c-) and nitrogen- (n-) starved mycelia and one library was generated from cultures of maturing perithecia (p). in other fungal pathogens, starvation conditions have been shown ...200312620255
an ordered collection of expressed sequences from cryphonectria parasitica and evidence of genomic microsynteny with neurospora crassa and magnaporthe grisea.cryphonectria parasitica, the causative agent of chestnut blight, has proven to be a tractable experimental system for studying fungal pathogenesis. moreover, the development of infectious cdna clones of c. parasitica hypoviruses, capable of attenuating fungal virulence, has provided the opportunity to examine molecular aspects of fungal plant pathogenesis in the context of biological control. in order to establish a genomic base for future studies of c. parasitica, the authors have analysed a c ...200312949163
mining microorganism est databases in the quest for new proteins.microorganisms with large genomes are commonly the subjects of single-round partial sequencing of cdna, generating expressed sequence tags (ests). usually there is a great distance between gene discovery by est projects and submission of amino acid sequences to public databases. we analyzed the relationship between available ests and protein sequences and used the sequences available in the secondary database, clusters of orthologous groups (cog), to investigate ests from eight microorganisms of ...200312917813
identification of five new blast resistance genes in the highly blast-resistant rice variety ir64 using a qtl mapping strategy.rice progenies used for the construction of genetic maps permit exhaustive identification and characterization of resistance genes present in their parental cultivars. we inoculated a rice progeny derived from the cross ir64 x azucena with different magnaporthe grisea isolates that showed differential responses on the parental cultivars. by qtl mapping, nine unlinked loci conferring resistance to each isolate were identified and named pi-24( t) to pi-32( t). they could correspond to nine specifi ...200312647052
serial analysis of gene expression (sage) of magnaporthe grisea: genes involved in appressorium formation.treatment with cyclic amp (camp) induces appressorium formation in the phytopathogenic fungus magnaporthe grisea, the causative agent of rice blast disease. in a search for the m. grisea genes responsible for appressorium formation and host invasion, sage (serial analysis of gene expression) was carried out using mrna isolated from fungal conidia germinating in the presence and absence of camp. from camp-treated conidia 5087 tags including 2889 unique tags were isolated, whereas untreated conidi ...200312955499
rna silencing in the phytopathogenic fungus magnaporthe oryzae.systematic analysis of rna silencing was carried out in the blast fungus magnaporthe oryzae (formerly magnaporthe grisea) using the enhanced green fluorescence protein (egfp) gene as a model. to assess the ability of rna species to induce rna silencing in the fungus, plasmid constructs expressing sense, antisense, and hairpin rnas were introduced into an egfp-expressing transformant. the fluorescence of egfp in the transformant was silenced much more efficiently by hairpin rna of egfp than by ot ...200312971600
purcopia, a ty1-copia truncated retroelement in the genome of claviceps purpurea.truncated copy of reverse transcriptase of ty1/copia retroelement (purcopia) was found as part of the species-specific rapd 257(540) marker of claviceps purpurea. a region of 94 bp with 78.9% identity to an unannotated region of the genomic clone of the rice blast fungus pyricularia grisea (accession no. aq162050) was found at the 5' end of the pseudogene. comparison with database sequences revealed that purcopia is close to the plant retroelements represented by tto1, ta1-3 and bare-1, whereas ...200312879745
[a study on introduction of chitinase gene and beta-1,3-glucanase gene into restorer line of dian-type hybrid rice (oryza sativa l.) and enhanced resistance to blast (magnaporthe grisea)].plasmid pblgc containing chitinase gene from phaseolus limensis and beta-1,3-glucanase gene from nicotiana tabacum was bombarded into the restorer line "nan29" of dian-type hybrid rice (oryza sativa l. ssp. japonica) from yunnan province of south-west china. 93 regenerants were obtained from the calli that were resistant to g418 (100 to 150 mg/l) on nb medium. using beta-1,3 glucanase gene as the probe, 17 of the regenerants were identified to be transgenic lines by dot blotting and the foreign ...200312812057
a blumeria graminis gene family encoding proteins with a c-terminal variable region with homologues in pathogenic fungi.in a study aimed at characterising, at the molecular level, the obligate biotrophic fungus blumeria graminis f. sp. hordei (bgh), we have identified a novel group of genes, the egh16h genes, and shown that two of these are up-regulated during primary infection of barley leaves. the genes have partial homology to a previously characterised bgh gene family, egh16. egh16 and egh16h are subfamilies of a larger multigene family with presently about 15 members identified in bgh. egh16h has about ten m ...200312853153
the g-beta subunit mgb1 is involved in regulating multiple steps of infection-related morphogenesis in magnaporthe grisea.trimeric g-proteins transmit extracellular signals to various downstream effectors (e.g. map kinases) in eukaryotes. in the rice blast fungus magnaporthe grisea, the pmk1 map kinase is essential for appressorium formation and infectious growth. the pmk1 deletion mutant fails to form appressoria but still responds to exogenous camp for tip deformation. since gene disruption mutants of three galpha subunits still form appressoria and are phenotypically different from pmk1 mutants, it is likely tha ...200314507377
genomic characterization of rim2/hipa elements reveals a cacta-like transposon superfamily with unique features in the rice genome.the availability of huge amounts of rice genome sequence now permits large-scale analysis of the structure and molecular characteristics of the previously identified transposase-encoding rim2 (also called hipa) element, which is transcriptionally activated by infection with the fungal pathogen magnaporthe grisea and by treatment with the corresponding fungal elicitor. based on genomic cloning and data mining from 230 mb of rice genome sequence, 347 rim2 elements, with an average size of 5.8 kb, ...200314513364
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