tps1 regulates the pentose phosphate pathway, nitrogen metabolism and fungal virulence.trehalose fulfils a wide variety of functions in cells, acting as a stress protectant, storage carbohydrate and compatible solute. recent evidence, however, indicates that trehalose metabolism may exert important regulatory roles in the development of multicellular eukaryotes. here, we show that in the plant pathogenic fungus magnaporthe grisea trehalose-6-phosphate (t6p) synthase (tps1) is responsible for regulating the pentose phosphate pathway, intracellular levels of nadph and fungal virulen ...200717641690
mnh6, a nonhistone protein, is required for fungal development and pathogenicity of magnaporthe grisea.mnh6, a nonhistone protein containing an hmg1 box, was isolated from the rice blast fungus, magnaporthe grisea. in the current study, we utilized an mnh6-deletion mutant to investigate the role of mnh6 in the disease cycle of m. grisea. the deltamnh6 mutant exhibited pleiotropic effects on fungal morphogenesis, including reduction in mycelial growth, conidiation, appressorium development, plant penetration, and infectious growth in host cells. furthermore, deltamnh6 mutant had greatly reduced pa ...200717644013
[controlling effects of multiple species coexistence on rice diseases, pests and weeds in paddy field ecosystem].establishing a species-diversified cropping system to control crop diseases, insect pests and weeds is an important approach to sustainable agricultural development. this paper reviewed the researches on paddy field species-diversified cropping systems at home and abroad, and discussed the controlling effects and mechanisms of multiple species coexistence on rice diseases, pests and weeds control. the multiple species coexistence models such as rice-fish, rice-duck, rice-azolla-fish and rice-azo ...200717650871
inhibition of the pathogenicity of magnaporthe grisea by bromophenols, isocitrate lyase inhibitors, from the red alga odonthalia corymbifera.magnaporthe grisea is a fungal pathogen of rice that forms appressoria that penetrate the outer cuticle of the rice plant. data from recent studies indicate that m. grisea isocitrate lyase (icl), a key enzyme in the glyoxylate cycle, is highly expressed during appressorium-mediated plant infection. bromophenols isolated from the red alga odonthalia corymbifera exhibited potent icl inhibitory activity and blocked appressoria formation by m. grisea in a concentration-dependent manner. in addition, ...200717655246
isolation and antifungal activity of lignans from myristica fragrans against various plant pathogenic a search for plant extracts with potent in vivo antifungal activity against various plant diseases, we found that treatment with a methanol extract of myristica fragrans houttyn (nutmeg) seeds reduced the development of various plant diseases. the objectives of the present study were to isolate and determine antifungal substances from my. fragrans and to evaluate their antifungal activities.200717659535
magnaporthe grisea cutinase2 mediates appressorium differentiation and host penetration and is required for full virulence.the rice blast fungus magnaporthe grisea infects its host by forming a specialized infection structure, the appressorium, on the plant leaf. the enormous turgor pressure generated within the appressorium drives the emerging penetration peg forcefully through the plant cuticle. hitherto, the involvement of cutinase(s) in this process has remained unproven. we identified a specific m. grisea cutinase, cut2, whose expression is dramatically upregulated during appressorium maturation and penetration ...200717704215
a new series of 3-alkyl phosphate derivatives of 4,5,6,7-tetrahydro-1-d-ribityl-1h-pyrazolo[3,4-d]pyrimidinedione as inhibitors of lumazine synthase: design, synthesis, and evaluation.lumazine synthase catalyzes the penultimate step in the biosynthesis of riboflavin. a homologous series of three pyrazolopyrimidine analogues of a hypothetical intermediate in the lumazine synthase-catalyzed reaction were synthesized and evaluated as lumazine synthase inhibitors. the key steps of the synthesis were c-5 deprotonation of 4-chloro-2,6-dimethoxypyrimidine, acylation of the resulting anion, and conversion of the product to a pyrazolopyrimidine with hydrazine. alkylation of the pyrazo ...200717705537
cellular differentiation and host invasion by the rice blast fungus magnaporthe grisea.this review describes current advances in understanding the biology of plant infection by the rice blast fungus magnaporthe grisea. development of the specialized infection structure, the appressorium, in m. grisea has recently been shown to be controlled by cell cycle progression and initiation of autophagic, programmed cell death in the fungal spore. re-cycling of the contents of the fungal spore and peroxisomal fatty acid beta-oxidation are therefore important processes for appressorium funct ...200717707684
improved gene targeting in magnaporthe grisea by inactivation of mgku80 required for non-homologous end joining.the ascomycete magnaporthe grisea is a model species for the study of plant fungal interactions. as in many filamentous fungi, targeted gene replacement occurs at low frequency in m. grisea (average 7%). mus52/ku80 is a gene essential for non-homologous end joining (nhej) of dna double-strand breaks. its deletion increases the frequency of targeted gene replacement in fungi [ninomiya, y., suzuki, k., ishii, c., inoue, h., 2004. highly efficient gene replacements in neurospora strains deficient f ...200817716934
disease resistance against magnaporthe grisea is enhanced in transgenic rice with suppression of omega-3 fatty acid desaturases.linolenic acid (18:3) is the most abundant fatty acid in plant membrane lipids and is a source for various oxidized metabolites, called oxylipins. 18:3 and oxylipins play important roles in the induction of defense responses to pathogen infection and wound stress in arabidopsis. however, in rice, endogenous roles for 18:3 and oxylipins in disease resistance have not been confirmed. we generated 18:3-deficient transgenic rice plants (f78ri) with co-suppression of two omega-3 fatty acid desaturase ...200717716996
cloning, sequencing and expression analysis of the nar promoter activated during hyphal stage of magnaporthe grisea.the promoter of nar gene in magnaporthe grisea was isolated and sequenced. the promoter sequences contained the "tata" box, the "caat" box, and binding sites for fungal regulatory proteins. programs that predict promoter sequences indicated that promoter sequence lies between locations 430 and 857 of the nar promoter fragment. gfp expression under the nar promoter and nar transcript analysis revealed that this promoter is activated primarily at the mycelial stage in the rice blast fungus and cou ...200717726747
a mechanism for surface attachment in spores of a plant pathogenic fungus.rice blast disease is caused by a fungus that attacks all above-ground parts of the rice plant. in a study of the means by which the fungus attaches to the hydrophobic rice leaf surface, it was found that spores(conidia) of the rice blast fungus magnaporthe grisea have a mechanism for immediate and persistent attachment to various surfaces, including teflon. this attachment occurs at the spore apex and is blocked by the addition of the lectin concanavalin a. microscopy of hydrated conidia shows ...198817769992
gcstua, an apses transcription factor, is required for generation of appressorial turgor pressure and full pathogenicity of glomerella cingulata.glomerella cingulata, which infects a number of different hosts, gains entry to the plant tissue by means of an appressorium. turgor pressure generated within the appressorium forces a penetration peg through the plant cuticle. a visible lesion forms as the fungus continues to grow within the host. a g. cingulata homolog (gcstua) of the genes encoding asm1, phd1, sok2, efg1, and stua transcription factors in magnaporthe grisea and other fungi was cloned and shown to be required for infection of ...200717849713
[analysis of simple sequence repeats in genomes of sclerotinia sclerotiorum and botrytis cinerea].simple sequence repeats or microsatellites have been used as genetic markers in population genetics because of their abundance and length variation between different individuals. this study examined the ssrs in the completely sequenced sclerotinia sclerotiorum and botrytis cinerea genomes. the occurrences, relative abundance, relative density, most common motifs, and the longest ssrs in the two species were analyzed, and compared with other plant pathogenic fungal species, such as fusarium grami ...200717855269
rice pti1a negatively regulates rar1-dependent defense responses.tomato (solanum lycopersicum) pto encodes a protein kinase that confers resistance to bacterial speck disease. a second protein kinase, pti1, physically interacts with pto and is involved in pto-mediated defense signaling. pti1-related sequences are highly conserved among diverse plant species, including rice (oryza sativa), but their functions are largely unknown. here, we report the identification of a null mutant for the pti1 homolog in rice and the functional characterization of os pti1a. th ...200717890377
susceptibility of rice to the blast fungus, magnaporthe grisea.the interaction between rice and the blast fungus magnaporthe grisea is the focus of extensive studies on rice disease resistance and fungal infection mechanisms. here, we review the characteristics of susceptible rice blast infections in terms of physiology, cytology and both host and pathogen transcriptional responses. the success of the infection and the type of disease symptoms strongly depend on environmental and developmental cues. after its penetration into a host cell, the fungus differe ...200817905473
a novel gene, pi40(t), linked to the dna markers derived from nbs-lrr motifs confers broad spectrum of blast resistance in rice.rice blast disease caused by magnaporthe grisea is a continuous threat to stable rice production worldwide. in a modernized agricultural system, the development of varieties with broad-spectrum and durable resistance to blast disease is essential for increased rice production and sustainability. in this study, a new gene is identified in the introgression line ir65482-4-136-2-2 that has inherited the resistance gene from an ee genome wild oryza species, o. australiensis (acc. 100882). genetic an ...200717909744
biological evaluation of neopeptins isolated from a streptomyces strain.microbial secondary metabolites are a rich source of antifungal agents and have merit as alternatives to synthetic fungicides. to develop disease control agents against powdery mildew, the lipopeptide antibiotic neopeptins were identified from the culture broth of a streptomyces sp., and in vivo control efficacy of the compounds was evaluated on cucumber plants under glasshouse conditions.200717912683
tripartite chimeric pseudogene from the genome of rice blast fungus magnaporthe grisea suggests double template jumps during long interspersed nuclear element (line) reverse transcription.a systematic survey of loci carrying retrotransposons in the genome of the rice blast fungus magnaporthe grisea allowed the identification of novel non-canonical retropseudogenes. these elements are chimeric retrogenes composed of dna copies from different cellular transcripts directly fused to each other. their components are copies of a non protein-coding highly expressed rna of unknown function termed weird and of two fungal retrotransposons: mgl and mg-sine. many of these chimeras are transc ...200717922896
2-epi-botcinin a and 3-o-acetylbotcineric acid from botrytis cinerea.two metabolites, 2-epi-botcinin a and 3-o-acetylbotcineric acid, were isolated from botrytis cinerea (aem211). the former compound was new, and the latter was known but structurally revised by us. in a test for antifungal activity against magnaporthe grisea, a pathogen of rice blast disease, 2-epi-botcinin a was 8 times less active than botcinin a (mic 100 microm), and the mic value for 3-o-acetylbotcineric acid being 100 microm.200717928694
a rho3 homolog is essential for appressorium development and pathogenicity of magnaporthe grisea.the small gtpase rho3 is conserved in fungi and plays a key role in the control of cell polarity and exocytosis in yeast. in this report, we show that a rho3 homolog, mgrho3, is dispensable for polarized hyphal growth in the rice blast fungus magnaporthe grisea. however, mgrho3 is required for plant infection. appressoria formed by the mgrho3 deletion mutants are morphologically abnormal and defective in plant penetration. conidia of the mgrho3 deletion mutants are narrower than those of the wil ...200717933908
[spotting the positions of t-dna on the genome for magnaporthe grisea transformants and study on the mode of t-dna insertion].using thermal asymmetric interlaced pcr (tail-pcr), 39 specifical fragments of magnaporthe grisea genomic dna flanked on the t-dna were successfully amplified from 37 m. grisea transformants randomly selected from the mutants induced by t-dna insertion in our laboratory. these fragments were sequenced and then compared by blast with the sequences of m. grisea genomic dna published in netwwork. t-dna insertion positions for 17 transformants were spotted on the genome of m. grisea. of all the 39 a ...200717944355
glufosinate ammonium-induced pathogen inhibition and defense responses culminate in disease protection in bar-transgenic rice.glufosinate ammonium diminished developments of rice (oryza sativa) blast and brown leaf spot in 35s:bar-transgenic rice. pre- and postinoculation treatments of this herbicide reduced disease development. glufosinate ammonium specifically impeded appressorium formation of the pathogens magnaporthe grisea and cochliobolus miyabeanus on hydrophobic surface and on transgenic rice. in contrast, conidial germination remained unaffected. glufosinate ammonium diminished mycelial growth of two pathogens ...200817981989
synthetic pyrazole derivatives as growth inhibitors of some phytopathogenic fungi.the present study was carried out to investigate the antifungal activity of pyrazole/isoxazole-3-carboxamido-4-carboxylic acids, 4-oxo-5-substituted pyrazolo[3,4-d]pyrimidine-6-thiones, and n-alkyl/aryl-n'-(4-carbethoxy-3-pyrazolyl)thioureas against pythium ultimum, botrytis cinerea, and magnaporthe grisea. the results on growth inhibition showed differences in the sensitivity of the three fungi to the tested substances, and in general p. ultimum was shown to be the most sensitive. on all phytop ...200718001038
expression of a harpin-encoding gene in rice confers durable nonspecific resistance to magnaporthe durable nonspecific resistance to phytopathogens is one of the ultimate goals of plant breeding. however, most attempts to reach this goal fail as a result of rapid changes in pathogen populations and the sheer diversity of pathogen infection mechanisms. in this study, we show that the expression of a harpin-encoding gene (hrf1), derived from xanthomonas oryzae pv. oryzae, confers nonspecific resistance in rice to the blast fungus magnaporthe grisea. transgenic plants and their t1-t7 ...200818005094
functional analysis of a novel abc transporter abc4 from magnaporthe grisea.the atp-binding cassette (abc) superfamily of membrane transporters has been implicated to play a role in pathogenesis in various phytopathogenic fungi. in an insertional mutagenesis screen for pathogenicity mutants of magnaporthe grisea obtained via agrobacterium tumefaciens-mediated transformation (atmt), a novel gene belonging to the abc transporter family was identified. the gene abc4 was predicted to be 5045 bp in length coding for a protein of 1654 amino acids. the mutant did not form func ...200818034832
isolation, purification and characterization of an antifungal molecule produced by bacillus licheniformis bc98, and its effect on phytopathogen magnaporthe grisea.isolation of bacterial antagonist for use in the biological control of phytopathogenic fungi like rice blast fungus, magnaporthe grisea, and to further purify and characterize the antifungal molecule produced by the antagonist.200718045418
antifungal cyclopeptolide from fungal saprophytic antagonist ulocladium atrum.the saprophytic fungus ulocladium atrum preuss is a promising biological control agent for botrytis cinerea in greenhouse- and field-grown crops. however, despite its known potent antifungal activity, no antifungal substance has yet been reported. in an effort to characterize the antifungal substance from u atrum, we isolated an antibiotic peptide. based on extensive spectroscopic analyses, its structure was established as a cyclopeptolide with a high portion of n-methylated amino acids, and its ...200718051337
xylarinic acids a and b, new antifungal polypropionates from the fruiting body of xylaria polymorpha.two new polypropionates designated as xylarinic acids a and b were isolated from the fruiting body of xylaria polymorpha. their structures were established as 4,6,8-trimethyl-2,4-decadienoic acid and 2,4,6-trimethyl-2-octenoic acid, respectively, on the basis of extensive spectroscopic analysis. both compounds displayed significant antifungal activity against plant pathogenic fungi pythium ultinum, magnaporthe grisea, aspergillus niger, alternaria panax, and fusarium oxysporium, whereas they did ...200718057699
constitutive expression of pathogen-inducible oswrky31 enhances disease resistance and affects root growth and auxin response in transgenic rice plants.wrky transcription factors have many regulatory roles in response to biotic and abiotic stresses. in this study, we isolated a rice wrky gene (oswrky31) that is induced by the rice blast fungus magnaporthe grisea and auxin. this gene encodes a polypeptide of 211 amino-acid residues and belongs to a subgroup of the rice wrky gene family that probably originated after the divergence of monocot and dicot plants. oswrky31 was found to be localized to the nucleus of onion epidermis cells to transient ...200818071364
identification of defense-related genes in rice responding to challenge by rhizoctonia solani.rice sheath blight, caused by rhizoctonia solani is one of the major diseases of rice. the pathogen infects rice plants directly through stomata or using lobate appressoria and hyphal masses called infection cushions. the infection structures were normally found at 36 h post-inoculation. during infection, the pathogenesis-related genes, pr1b and pbz1 were induced in rice plants. to identify rice genes induced early in the defense response, suppression subtractive hybridization (ssh) was used to ...200818075727
rar1 and hsp90 form a complex with rac/rop gtpase and function in innate-immune responses in rice.a rice (oryza sativa) rac/rop gtpase, os rac1, is involved in innate immunity, but its molecular function is largely unknown. rar1 (for required for mla12 resistance) and hsp90 (a heat shock protein 90 kd) are important components of r gene-mediated disease resistance, and their function is conserved in several plant species. hsp90 has also recently been shown to be important in mammalian innate immunity. however, their functions at the molecular level are not well understood. in this study, we ...200718156216
large-scale expressed sequence tag analysis for the chestnut blight fungus cryphonectria parasitica.cryphonectria parasitica is the causal fungal agent responsible for the chestnut blight disease. we report the generation of 14,263 expressed sequence tags representing 6318 unisequences for the fungus. functional annotation of these unisequences revealed different gene expression patterns for wild-type and hypovirus-infected cultures at the sporulation stage and allowed the reconstruction of key c. parasitica signal transduction pathways conserved in the sorbidaryomycetes. a list of homologous ...200818166491
evidence for horizontal transfer of a secondary metabolite gene cluster between fungi.filamentous fungi synthesize many secondary metabolites and are rich in genes encoding proteins involved in their biosynthesis. genes from the same pathway are often clustered and co-expressed in particular conditions. such secondary metabolism gene clusters evolve rapidly through multiple rearrangements, duplications and losses. it has long been suspected that clusters can be transferred horizontally between species, but few concrete examples have been described so far.200818218086
homologs of toxb, a host-selective toxin gene from pyrenophora tritici-repentis, are present in the genome of sister-species pyrenophora bromi and other members of the ascomycota.pyrenophora tritici-repentis requires the production of host-selective toxins (hsts) to cause the disease tan spot of wheat, including ptr toxa, ptr toxb, and ptr toxc. pyrenophora bromi, the species most closely related to p. tritici-repentis, is the causal agent of brown leaf spot of bromegrass. because of the relatedness of p. bromi and p. tritici-repentis, we investigated the possibility that p. bromi contains sequences homologous to toxa and/or toxb, the products of which may be involved in ...200818226934
fungi have three tetraspanin families with distinct functions.tetraspanins are small membrane proteins that belong to a superfamily encompassing 33 members in human and mouse. these proteins act as organizers of membrane-signalling complexes. so far only two tetraspanin families have been identified in fungi. these are pls1, which is required for pathogenicity of the plant pathogenic ascomycetes, magnaporthe grisea, botrytis cinerea and colletotrichum lindemuthianum, and tsp2, whose function is unknown. in this report, we describe a third family of tetrasp ...200818241352
biochemical and molecular characterization of a putative endoglucanase in magnaporthe grisea.microbial pathogens secrete an array of cell wall-degrading enzymes to break down the structure of the host cell wall to facilitate colonization of the host tissue. to better understand their role in the pathogenesis, a putative endoglucanase from magnaporthe grisea was characterized in this paper. signalp-3.0 analysis indicates that the protein encoded by gene mgg_02532.5 in m. grisea (named mgegl1 for m. grisea endoglucanase 1) contains a secretory signal peptide. multiple alignment shows that ...200818247030
[application of binding spectra in dmis fungicide screening].in order to establish a fast and accurate method for novel dmis fungicide screening, lanosterol 14alpha-demethylase of magnaporthe grisea expressed in e. coli was used as target enzyme and the dmi fungicides diniconazole, tebuconazole, triadimenol and triadimefon were used as representative fungicides, the effects of enzyme activity, enzyme purity and concentration on the binding spectra were investigated. the results showed that active enzyme, elimination of interference of other p450s and prop ...200718257249
biosynthesis of secondary metabolites in the rice blast fungus magnaporthe grisea: the role of hybrid pks-nrps in pathogenicity.fungal secondary metabolites are an important source of bioactive compounds for agrochemistry and pharmacology. over the past decade, many studies have been undertaken to characterize the biosynthetic pathways of fungal secondary metabolites. this effort has led to the discovery of new compounds, gene clusters, and key enzymes, and has been greatly supported by the recent releases of fungal genome sequences. in this review, we present results from a search for genes involved in secondary metabol ...200818272356
cell cycle and cell death are not necessary for appressorium formation and plant infection in the fungal plant pathogen colletotrichum order to initiate plant infection, fungal spores must germinate and penetrate into the host plant. many fungal species differentiate specialized infection structures called appressoria on the host surface, which are essential for successful pathogenic development. in the model plant pathogen magnaporthe grisea completion of mitosis and autophagy cell death of the spore are necessary for appressoria-mediated plant infection; blocking of mitosis prevents appressoria formation, and prevention of ...200818275611
robust-longsage (rl-sage): an improved longsage method for high-throughput transcriptome analysis.serial analysis of gene expression (sage) is a powerful technique for large-scale transcriptome analysis in eukaryotes. however, technical difficulties in the sage library construction, such as low concatemer cloning efficiency, small concatemer size, and a high level of empty clones, has prohibited its widespread use as a routine technique for expression profiling in many laboratories. we recently improved the longsage library construction method considerably and developed a modified version ca ...200818287620
methods for analysis of gene expression in plants using mpss.massively parallel signature sequencing (mpss) is a technology capable of sequencing simultaneously almost all the dna molecules in a sample. this technology is well suited for deep profiling of mrna and small rna by the sequencing of cdna tags. a series of mrna mpss databases has been created from various libraries derived from four different species (arabidopsis, rice, grape, and magnaporthe grisea, the rice blast fungus). our mrna mpss databases measure the absolute expression level of most g ...200718287704
molecular evolution and diversity of lignin degrading heme peroxidases in the agaricomycetes.the plant and microbial peroxidase superfamily encompasses three classes of related protein families. class i includes intracellular peroxidases of prokaryotic origin, class ii includes secretory fungal peroxidases, including the lignin degrading enzymes manganese peroxidase (mnp), lignin peroxidase (lip), and versatile peroxidase (vp), and class iii includes the secretory plant peroxidases. here, we present phylogenetic analyses using maximum parsimony and bayesian methods that address the orig ...200818292958
programmed cell death in pathogenic fungi.greater understanding of programmed cell death (pcd) responses in pathogenic fungi may offer a chance of exploiting the fungal molecular death machinery to control fungal infections. clearly identifiable differences between the death machineries of pathogens and their hosts, make this a feasible target. evidence for pcd in a range of pathogenic fungi is discussed alongside an evaluation of the capacity of existing antifungal agents to promote apoptosis and other forms of cell death. information ...200818294459
elicitor and calatalse activity of conidia suspensions of various strains of magnaporthe grisea in suspension-cultured cells of rice.a conidia suspension of magnaporthe grisea carried elicitor activity that induced the expression of defense-related genes and the production of h(2)o(2) in suspension-cultured rice cells. the levels of h(2)o(2) produced were dependent on fungal isolates and were correlated with the catalase activity in the supernatant fraction of each conidia suspension, not with gene-for-gene interactions.200818323633
rice blast infection of brachypodium distachyon as a model system to study dynamic host/pathogen interactions.interactions between plants and compatible fungal pathogens are spatially and temporally dynamic, posing a major challenge for sampling and data analysis. a protocol is described for the infection of the model grass species brachypodium distachyon with magnaporthe grisea (rice blast), together with modifications to extend the use to rice and barley. we outline a method for the preparation of long-term stocks of virulent fungal pathogens and for the generation of fungal inoculants for challenge o ...200818323815
mads-box transcription factor mig1 is required for infectious growth in magnaporthe grisea.magnaporthe grisea is a model fungus for studying fungus-plant interactions. two mitogen-activated protein (map) kinase genes, pmk1 and mps1, have been implicated in regulating plant infection processes in m. grisea. however, transcription factors activated by these map kinases are not well studied. in this study we functionally characterized the mig1 gene that encodes a mads-box transcription factor homologous to saccharomyces cerevisiae rlm1. in yeast two-hybrid assays, mig1 interacts with mps ...200818344407
inactivation of pqq genes of enterobacter intermedium 60-2g reduces antifungal activity and induction of systemic resistance.enterobacter intermedium 60-2g, a phosphate solubilizing bacterium, has the ability to induce systemic resistance in plants against soft rot pathogen erwinia carotovora. glucose dehydrogenase, an enzyme that utilizes pyrroloquinoline quinone (pqq) as a cofactor, is required for the synthesis of gluconic acid by e. intermedium 60-2g. here, we report that the pqqa and pqqb genes are required for phosphate solubilization and induced systemic resistance against a soft rot pathogen in tobacco. mutati ...200818355275
enhancement of disease resistance to magnaporthe grisea in rice by accumulation of hydroxy linoleic acid.linoleic acid (18:2) and linolenic acid (18:3) are sources for various oxidized metabolites called oxylipins, some of which inhibit growth of fungal pathogens. in a previous study, we found disease resistance to rice blast fungus magnaporthe grisea enhanced in 18:2-accumulating transgenic rice (f78ri) in which the conversion from 18:2 to 18:3 was suppressed. here, we demonstrate that 18:2-derived hydroperoxides and hydroxides (hpodes and hodes, respectively) inhibit growth of m. grisea more stro ...200818373976
genome organization and evolution of the avr-pita avirulence gene family in the magnaporthe grisea species complex.the avirulence (avr) gene avr-pita in magnaporthe oryzae prevents the fungus from infecting rice cultivars containing the resistance gene pi-ta. a survey of isolates of the m. grisea species complex from diverse hosts showed that avr-pita is a member of a gene family, which led us to rename it to avr-pita1. avirulence function, distribution, and genomic context of two other members, named avr-pita2 and avr-pita3, were characterized. avr-pita2, but not avr-pita3, was functional as an avr gene cor ...200818393625
regulation of expression of rice thaumatin-like protein: inducibility by elicitor requires promoter w-box elements.rice thaumatin-like protein (rtlp1) is a high-molecular-weight antimicrobial pathogenesis-related protein that plays a role in plant stress response. this study examines transcriptional regulation of rtlp1 using wild type and transgenic rice plants carrying a beta-glucuronidase (gus) reporter gene driven by the rtlp1 promoter (prtlp1gus). the rtlp1 promoter is induced within 6 h after infection with rice blast fungus (magnaporthe grisea). the rtlp1 promoter is also induced by salicylic acid (sa) ...200818425517
magnaporthe grisea avirulence gene ace1 belongs to an infection-specific gene cluster involved in secondary metabolism.the avirulence gene ace1 from the rice blast fungus magnaporthe grisea encodes a polyketide synthase (pks) fused to a nonribosomal peptide synthetase (nrps) probably involved in the biosynthesis of a secondary metabolite recognized by pi33 resistant rice (oryza sativa) cultivars. analysis of the m. grisea genome revealed that ace1 is located in a cluster of 15 genes, of which 14 are potentially involved in secondary metabolism as they encode enzymes such as a second pks-nrps (syn2), two enoyl re ...200818433432
osbirh1, a dead-box rna helicase with functions in modulating defence responses against pathogen infection and oxidative stress.dead-box proteins comprise a large protein family with members from all kingdoms and play important roles in all types of processes in rna metabolism. in this study, a rice gene osbirh1, which encodes a dead-box rna helicase protein, was cloned and characterized. the predicted osbirh1 protein contains a dead domain and all conserved motifs that are common characteristics of dead-box rna helicases. recombinant osbirh1 protein purified from escherichia coli was shown to have both rna-dependent atp ...200818441339
development of near-isogenic japonica rice lines with enhanced resistance to magnaporthe grisea.thirteen near-isogenic lines (nils) of japonica rice were developed via a backcross method using the recurrent parent chucheong, which is of good eating quality but is susceptible to magnaporthe grisea, and three blast resistant japonica donors, seolak, daeseong and bongkwang. the agro-morphological traits of these nils, such as heading date, culm length, and panicle length, were similar to those of chucheong. in a genome-wide scan using 158 ssr markers, chromosome segments of chucheong were ide ...200818443412
molecular genetic analysis of the rice blast fungus, magnaporthe grisea. 199118479196
functional analysis reveals pleiotropic effects of rice ring-h2 finger protein gene osbirf1 on regulation of growth and defense responses against abiotic and biotic stresses.ring finger proteins comprise a large family and play key roles in regulating growth/developmental processes, hormone signaling and responses to biotic and abiotic stresses in plants. a rice gene, osbirf1, encoding a putative ring-h2 finger protein, was cloned and identified. osbirf1 encodes a 396 amino acid protein belonging to the atl family characterized by a conserved ring-h2 finger domain (c-x2-c-x15-c-x1-h-x2-h-x2-c-x10-c-x2-c), a transmembrane domain at the n-terminal, a basic amino acid ...200818496756
development and evaluation of a high-throughput, low-cost genotyping platform based on oligonucleotide microarrays in rice.abstract:200818510771
physiological and cytological mechanisms of silicon-induced resistance in rice against blast disease.rice (oryza sativa l.) blast disease caused by magnaporthe grisea is one of the most destructive diseases in the rice-growing areas of the world. silicon is an important nutritional element especially for rice. two near-isogenic lines of rice with different resistance to blast disease, i.e. co39 (susceptible) and c101lac (pi-1) (resistant), were selected to determine the effects of si amendment on the severity and incidence of rice blast disease. the physiological and cytological mechanisms invo ...200818513376
a rice serine carboxypeptidase-like gene osbiscpl1 is involved in regulation of defense responses against biotic and oxidative stress.serine carboxypeptidase-like proteins (scpls) comprise a large family of protein hydrolyzing enzymes that play roles in multiple cellular processes. during the course of study aimed at elucidating the molecular basis of induced immunity in rice, a gene, osbiscpl1, encoding a putative scpl, was isolated and identified. osbiscpl1 contains a conserved peptidase s10 domain, serine active site and a signal peptide at n-terminus. osbiscpl1 is expressed ubiquitously in rice, including roots, stems, lea ...200818571878
overexpression of a rice defense-related f-box protein gene osdrf1 in tobacco improves disease resistance through potentiation of defense gene expression.f-box proteins play important roles in plant growth/development and responses to environmental stimuli through targeting substrates into degradation machinery. a rice defense-related f-box protein gene, osdrf1, was cloned and identified during a course of study aimed at elucidating the molecular basis of induced immunity in rice. osdrf1 encodes a protein of 328 amino acids, containing a highly conserved f-box domain. expression of osdrf1 was induced upon treatment with benzothiadiazole (bth), a ...200818573188
determining the fertility status of setaria infecting magnaporthe grisea isolates with standard testers and identification of tolerant cultivar of setaria italica.a total of 128 isolates of setaria-infecting magnaporthe grisea strains were obtained from different states of south india which includes sampling sites from tamil nadu, two from karnataka, one from andhra pradesh and kerala. out of the selected 128 isolates 30 strains were tested with mat1-1 and mat1-2 fertile standard testers to determine their mating type. none of the 30 setaria isolates produced perithecia with fertile testers. however, when monoconidial isolates were mated among themselves, ...200818597182
molecular evolution of the pi-ta gene resistant to rice blast in wild rice (oryza rufipogon).rice blast disease resistance to the fungal pathogen magnaporthe grisea is triggered by a physical interaction between the protein products of the host r (resistance) gene, pi-ta, and the pathogen avr (avirulence) gene, avr-pita. the genotype variation and resistant/susceptible phenotype at the pi-ta locus of wild rice (oryza rufipogon), the ancestor of cultivated rice (o. sativa), was surveyed in 36 locations worldwide to study the molecular evolution and functional adaptation of the pi-ta gene ...200818622033
overexpression of a rice diacylglycerol kinase gene osbidk1 enhances disease resistance in transgenic tobacco.a rice diacylglycerol kinase (dgk) gene, osbidk1, which encodes a 499-amino acid protein, was cloned and characterized. osbidk1 contains a conserved dgk domain, consisting of a diacylglycerol kinase catalytic subdomain and a diacylglycerol kinase accessory subdomain. expression of osbidk1 in rice seedlings was induced by treatment with benzothiadiazole (bth), a chemical activator of the plant defense response, and by infection with magnaporthe grisea, causal agent of blast disease. in bth-treate ...200818679055
development of microsatellite markers and construction of genetic map in rice blast pathogen magnaporthe grisea.magnaporthe grisea is the most destructive fungal pathogen of rice and a model organism for studying plant-pathogen interaction. molecular markers and genetic maps are useful tools for genetic studies. in this study, based on the released genome sequence data of m. grisea, we investigated 446 simple sequence repeat (ssr) loci and developed 313 ssr markers, which showed polymorphisms among nine isolates from rice (including a laboratory strain 2539). the number of alleles of each marker ranged 2- ...200818694839
expression of a bacterial flagellin gene triggers plant immune responses and confers disease resistance in transgenic rice plants.flagellin is a component of bacterial flagella and acts as a proteinaceous elicitor of defence responses in organisms. flagellin from a phytopathogenic bacterium, acidovorax avenae strain n1141, induces immune responses in suspension-cultured rice cells. to analyse the function of flagellin in rice, we fused the n1141 flagellin gene to the cauliflower mosaic virus 35s promoter and introduced it into rice. many of the resulting transgenic rice plants accumulated flagellin at various levels. the t ...200818705865
evolutionary history of the ancient cutinase family in five filamentous ascomycetes reveals differential gene duplications and losses and in magnaporthe grisea shows evidence of sub- and neo-functionalization.* the cuticle is the first barrier for fungi that parasitize plants systematically or opportunistically. here, the evolutionary history is reported of the multimembered cutinase families of the plant pathogenic ascomycetes magnaporthe grisea, fusarium graminearum and botrytis cinerea and the saprotrophic ascomycetes aspergillus nidulans and neurospora crassa. * molecular taxonomy of all fungal cutinases demonstrates a clear division into two ancient subfamilies. no evidence was found for lateral ...200818713314
[construction of cdna library of magnaporthe grisea with magnetic bead].we constructed cdna library of magnaporthe grisea. the good quality cdna library could facilitate finding proteinaceous elicitors of m. grisea, and elucidating the mechanisms of the m. grisea--rice interaction.200818720847
the crucial role of the pls1 tetraspanin during ascospore germination in podospora anserina provides an example of the convergent evolution of morphogenetic processes in fungal plant pathogens and saprobes.pls1 tetraspanins were shown for some pathogenic fungi to be essential for appressorium-mediated penetration into their host plants. we show here that podospora anserina, a saprobic fungus lacking appressorium, contains papls1, a gene orthologous to known pls1 genes. inactivation of papls1 demonstrates that this gene is specifically required for the germination of ascospores in p. anserina. these ascospores are heavily melanized cells that germinate under inducing conditions through a specific p ...200818757568
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
tetracyclic terpenoids from dasyscyphus niveus, dasyscyphins d and e.cultures of the ascomycete dasyscyphus niveus have yielded two new tetracyclic dasyscyphin-type terpenoids (1 and 2), and their structures were elucidated by nmr spectroscopy and x-ray crystallography. the absolute configuration of dasyscyphin d (1) was determined by synthesis and nmr spectroscopy of diastereomeric mtpa esters. both compounds inhibited the germination of conidia of magnaporthe grisea at 25 microg/ml.200818771321
resistance to magnaporthe grisea in transgenic rice with suppressed expression of genes encoding allene oxide cyclase and phytodienoic acid reductase.linolenic acid (18:3) and its derivative jasmonic acid (ja) are important molecules in disease resistance in many dicotyledonous plants. we have previously used 18:3- and ja-deficient rice (f78ri) to investigate the roles of fatty acids and their derivatives in resistance to the blast fungus magnaporthe grisea [a. yara, t. yaeno, j.-l. montillet, m. hasegawa, s. seo, k. kusumi, k. iba, enhancement of disease resistance to magnaporthe grisea in rice by accumulation of hydroxy linoleic acid, bioch ...200818786507
refunctionalization of the ancient rice blast disease resistance gene pit by the recruitment of a retrotransposon as a promoter.the plant genome contains a large number of disease resistance (r) genes that have evolved through diverse mechanisms. here, we report that a long terminal repeat (ltr) retrotransposon contributed to the evolution of the rice blast resistance gene pit. pit confers race-specific resistance against the fungal pathogen magnaporthe grisea, and is a member of the nucleotide-binding site leucine-rich repeat (nbs-lrr) family of r genes. compared with the non-functional allele pit(npb), the functional a ...200918808453
trichoderma g protein-coupled receptors: functional characterisation of a camp receptor-like protein from trichoderma atroviride.galpha subunits act to regulate vegetative growth, conidiation, and the mycoparasitic response in trichoderma atroviride. to extend our knowledge on g protein signalling, we analysed g protein-coupled receptors (gpcrs). as the genome sequence of t. atroviride is not publicly available yet, we carried out an in silico exploration of the genome database of the close relative t. reesei. twenty genes encoding putative gpcrs distributed over eight classes and additional 35 proteins similar to the mag ...200818836726
mglig4, a homolog of neurospora crassa mus-53 (dna ligase iv), is involved in, but not essential for, non-homologous end-joining events in magnaporthe many eukaryotic organisms, the non-homologous end-joining (nhej) system is a major pathway for the repair of dna double-strand breaks (dsbs). dna ligase iv is a component of the nhej system and is strictly required for the nhej system in saccharomyces cerevisiae and in neurospora crassa. to investigate the functions of dna ligase iv in magnaporthe grisea, we generated deletion mutants of mglig4, which encodes a homolog of n. crassa dna ligase iv. mutants (mglig4) showed no defects in asexual ...200818854221
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
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
identification of an avirulence gene in the fungus magnaporthe grisea corresponding to a resistance gene at the pik locus.abstract a rice isolate of magnaporthe grisea collected from china was avirulent on rice cvs. hattan 3 and 13 other japanese rice cultivars. the rice cv. hattan 3 is susceptible to almost all japanese blast fungus isolates from rice. the genetic basis of avirulence in the chinese isolate on japanese rice cultivars was studied using a cross between the chinese isolate and a laboratory isolate. the segregation of avirulence or virulence was studied in 185 progeny from the cross, and monogenic cont ...200518943008
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
identification of specific fragments of hpag xooc, a harpin from xanthomonas oryzae pv. oryzicola, that induce disease resistance and enhance growth in plants.harpin proteins from gram-negative plant-pathogenic bacteria can stimulate hypersensitive cell death (hcd) and pathogen defense as well as enhance growth in plants. two of these diverse activities clearly are beneficial and may depend on particular functional regions of the proteins. identification of beneficial and deleterious regions might facilitate the beneficial use of harpin-related proteins on crops without causing negative effects like cell death. here, we report the identification and t ...200818943254
genetic structure of magnaporthe grisea populations associated with st. augustinegrass and tall fescue in georgia.abstract amplified fragment length polymorphisms (aflps) were used to estimate phylogenetic relationships within magnaporthe grisea and determine the genetic structure of m. grisea populations associated with tall fescue and st. augustinegrass in georgia. sixteen clonal lineages were identified in a sample population of 948 isolates. five lineages were isolated from tall fescue (e, g1, g2, g4, and h), with lineage g4 comprising 90% of the population. isolates from tall fescue were closely relate ...200518943310
bacterial populations associated with rice seed in the tropical environment.abstract during the 1995 wet season, harvested rice seed was collected from farmers' fields at different locations in iloilo, philippines. bacterial isolations from crushed seed yielded 428 isolates. the isolates were characterized by box-polymerase chain reaction fingerprinting of total genomic dna and represented 151 fingerprint types (fpt). most fpts were found on a single occasion, although matching fingerprints for isolates from different samples also were found. identifications were made b ...200118943348
rice defense mechanisms against cochliobolus miyabeanus and magnaporthe grisea are distinct.abstract responses of rice to magnaporthe grisea and cochliobolus miyabeanus were compared. in tetep, a rice cultivar resistant to both fungi, pathogen inoculation rapidly triggered the hypersensitive reaction (hr), resulting in microscopic cell death. in rice cv. nakdong, susceptible to both pathogens, m. grisea did not cause hr, whereas c. miyabeanus caused rapid cell death similar to that associated with hr, which appeared similar to that observed in cv. tetep, yet failed to block fungal rami ...200518943354
characterization of pyricularia grisea in the united states using independent genetic and molecular markers.abstract a total of 540 isolates of pyricularia grisea from rice in the united states were examined for vegetative compatibility, mgr586 dna fingerprint diversity, and mating type based on hybridization with the mat1-1 and mat1-2 sexual mating type alleles. the collections contained both archived and contemporary field isolates representative of the known mgr586 lineages and races that occur throughout the united states. complementary nitrate nonutilizing (nit) or sulfate nonutilizing (sul) muta ...200018943382
silicon enhances the accumulation of diterpenoid phytoalexins in rice: a potential mechanism for blast resistance.abstract although several reports underscore the importance of silicon (si) in controlling magnaporthe grisea on rice, no study has associated this beneficial effect with specific mechanisms of host defense responses against this fungal attack. in this study, however, we provide evidence that higher levels of momilactone phytoalexins were found in leaf extracts from plants inoculated with m. grisea and amended with silicon (si(+)) than in leaf extracts from inoculated plants not amended with sil ...200418943541
identification and characterization of a new blast resistance gene located on rice chromosome 1 through linkage and differential analyses.abstract the chinese native cv. q14 expresses a high level of resistance to many isolates of pyricularia grisea collected from japan, thailand, and china. q14 was crossed to an indica-susceptible cultivar, q61. to rapidly determine the chromosomal location of the major resistance gene present in the cultivar, a linkage analysis using microsatellite markers was performed in the f(2) population segregating 3r:1s (resistant/susceptible) through bulked-segregant analysis (bsa) in combination with re ...200418943771
rice pi-ta gene confers resistance to the major pathotypes of the rice blast fungus in the united states.abstract the pi-ta gene in rice prevents the infection by magnaporthe grisea strains containing the avr-pita avirulence gene. the presence of pi-ta in rice cultivars was correlated completely with resistance to two major pathotypes, ib-49 and ic-17, common in the u.s. blast pathogen population. the inheritance of resistance to ic-17 was investigated further using a marker for the resistant pi-ta allele in an f(2) population of 1,345 progeny from a cross of cv. katy with experimental line ru91010 ...200418943978
development of co-dominant amplified polymorphic sequence markers in rice that flank the magnaporthe grisea resistance gene pi7(t) in recombinant inbred line 29.abstract pi7(t), a dominant blast resistance gene derived from the rice cultivar moroberekan, confers complete resistance against the fungal pathogen magnaporthe grisea. pi7(t) previously was positioned on chromosome 11 by restriction fragment length polymorphism (rflp) mapping of a recombinant inbred line population. one derivative of this population, recombinant inbred line (ril)29, was designated as the representative line for pi7(t). a segregating f2 population was created from ril29 in orde ...200418943979
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
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
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
the influence of silicon on components of resistance to blast in susceptible, partially resistant, and resistant cultivars of rice.abstract the application of silicon (si) fertilizers reduces the severity of blast, caused by magnaporthe grisea, in irrigated and upland rice; however, little research has been conducted to examine the epidemiological and etiological components of this reduction. four cultivars of rice with differential susceptibilities to race ib-49 of m. grisea were fertilized with three rates of a calcium silicate fertilizer and inoculated with the pathogen to test the effects of si on the following componen ...200118944279
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
expression analysis of rice defense-related genes in turfgrass in response to magnaporthe grisea.abstract magnaporthe grisea (anamorph = pyricularia grisea) causes blast on rice (oryza sativa) and gray leaf spot on turfgrass. gray leaf spot is a serious disease on st. augustinegrass (stenotaphrum secundatum), perennial ryegrass (lolium perenne), and tall fescue (festuca arundinacea). virulence assays performed in this study revealed that m. grisea collected from rice could also cause disease on st. augustinegrass and tall fescue. one rice isolate, che86061, caused similar disease reactions ...200718944372
analysis of host species specificity of magnaporthe grisea toward wheat using a genetic cross between isolates from wheat and foxtail millet.abstract a genetic cross was performed between a setaria isolate (pathogenic on foxtail millet) and a triticum isolate (pathogenic on wheat) of magnaporthe grisea to elucidate genetic mechanisms of its specific parasitism toward wheat. a total of 80 f(1) progenies were obtained from 10 mature asci containing 8 ascospores. lesions on wheat leaves produced by the f(1) progenies were classified into four types, which segregated in a 1:1:1:1 ratio. this result suggested that the pathogenicity of the ...200018944467
a target-site-specific screening system for antifungal compounds on appressorium formation in magnaporthe grisea.abstract chemical fungicides are a major method of control for plant diseases in spite of potential negative effects on the environment and the appearance of resistant strains. development of new chemical fungicides has been largely dependent upon in vivo efficacy tests in the greenhouse or in fields, which is in contrast to target-oriented in vitro screening systems widely used in the pharmaceutical field. to establish a target-site-specific screening system for antifungal compounds, specific i ...200018944481
pathogenic variability of pyricularia grisea from the high- and mid-elevation zones of bhutan.abstract thirty isolates of p. griseacollected from rice during a blast epidemic in 1995 in the high (1,800 to 2,600 m) and middle (1,200 to 1,800 m) elevations of bhutan and 80 isolates collected from one rice cultivar from two high- and two mid-elevation sites in 1996 were analyzed for virulence. differential varieties were indica co39, with five near-isogenic lines (nils) for resistance genes in the genetic background of co39, and japonica lijiangxintuanheigu (lth), with five nils for lth. tw ...200018944542
the xylanolytic system of claviceps purpurea: cytological evidence for secretion of xylanases in infected rye tissue and molecular characterization of two xylanase genes.abstract claviceps purpurea is a common phytopathogenic fungus that colonizes ovarian tissue of grasses. a concerted approach involving cytological and molecular techniques was initiated to investigate the role of the fungus' xylanolytic system in the interaction. using enzyme-gold and immuno-gold electron-microscopic techniques, the presence of arabinoxylans in cell walls of rye ovarian tissues (i.e., along the usual path of infection of c. purpurea) was confirmed; tissue-print and immunostaini ...199818944813
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