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1.
Susceptibility of rice to the blast fungus, Magnaporthe grisea 总被引:6,自引:0,他引:6
Ribot C Hirsch J Balzergue S Tharreau D Nottéghem JL Lebrun MH Morel JB 《Journal of plant physiology》2008,165(1):114-124
2.
Recent developments have been made in the identification of signal transduction pathways and gene products involved in the infection-related development of the rice blast fungus, Magnaporthe grisea. It has been established that cAMP-dependent and MAP kinase-mediated signaling are both critical for appressorium morphogenesis and function. These signaling pathways may act downstream of hydrophobin-mediated surface sensing by the growing germ tube. Several genes have been identified that are required for invasive growth of M. grisea including genes that allow adaptation of fungal metabolism to growth within plant tissues. 相似文献
3.
The 1.6 and 1.8 kbp dsRNAs have been found in the rice blast fungus, Magnaporthe grisea strain MG01. These dsRNA molecules are located in cytoplasm of the fungal cells and maintained stably during vegetative growth. Three crosses between dsRNA free and dsRNA containing strains including a parental cross, sib-mating and back cross were made to follow the inheritance of dsRNAs during sexual reproduction. Approximately 10% of ascospore progenies (11 out of 105) contained dsRNAs from all three crosses. These data indicate that dsRNAs of M. grisea are inherited at a low frequency and not in a Mendelian fashion. 相似文献
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Autophagy is a ubiquitous and evolutionarily conserved process found in all eukaryotic cells that allows for the degradation and recycling of old proteins and organelles. Starvation can induce autophagy, and autophagic pathway is an essential process for cellular function under starvation. In Magnaporthe grisea, starvation is one of the key induced factors for the germ tube tip to differentiate into an appressorium. Considering the importance of the rice blast fungus as a primary model for host-pathogen interaction, the role of autophagy in fungal development, appressorium turgor generation and pathogenicity of M. grisea via its role in organelle and protein turnover is a very significant subject. 相似文献
6.
The fungus, Magnaporthe grisea (Rice blast fungus) is a major agricultural problem affecting rice and related food crops. The way that the fungus invades the host plant and propagates itself is a very important scientific problem and recent advances in research into the genetic basis of these processes can be used to build a simple partial model using hybrid computational modelling techniques. The possible potential benefits of doing this include the use of computer simulation and automated analysis through techniques such as model checking to understand the complex behaviour of such systems. The example is a metaphor for the process of trying to integrate and understand much of the vast amounts of genomic and other data that is being produced in current molecular biology research. 相似文献
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A transformation method based on a dominant selectable marker (benomyl resistance) was developed for the rice blast fungus Magnaporthe grisea. The heterologous gene for -tubulin from Neurospora crassa (pBT3) was used to obtain benomyl-resistant M. grisea transformants at a frequency of 20 to 30/g of DNA. Control transformations carried out with a plasmid conferring hygromycin resistance or a derivative of pBT3 containing a repetitive DNA sequence, yielded the same frequency of transformation as that of pBT3. Molecular analysis of the transformants indicated multiple integration of the vector DNA. 相似文献
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Microsatellite markers for population studies of the rice blast fungus,Magnaporthe grisea 总被引:1,自引:0,他引:1
H. ADREIT D. ANDRIANTSIMIALONA D. W. UTAMI J. L. NOTTEGHEM M. H. LEBRUN D. THARREAU 《Molecular ecology resources》2007,7(4):667-670
We developed nine new microsatellite markers for rice blast (Magnaporthe grisea) population studies. These markers were used in addition to nine microsatellite markers previously developed by our group for mapping purpose. Altogether, the 18 markers were used in multiplex PCR (polymerase chain reaction) to characterize six populations from different geographical origins. The average number of alleles per locus across populations ranged from 1.2 to 7 and the total number of alleles detected from 2 to 19. Based on this large range of polymorphism, this set of markers is expected to be useful for different kind of population studies at different geographical scales. 相似文献
11.
Proteome analysis of rice blast fungus (Magnaporthe grisea) proteome during appressorium formation 总被引:1,自引:0,他引:1
We used two-dimensional gel electrophoresis (2-DE) to identify the proteins that are induced in the rice blast fungus Magnaporthe grisea during appressorium formation. Proteins were extracted from conidia that had germinated on hydrophilic glass plates or from germinated and appressoria-forming conidia on leaf wax-coated hydrophobic glass plates after 4, 8, and 12 h of incubation. Differentially expressed protein spots during appressorium formation were confirmed from gels after 2-DE analysis where proteins had been labeled with (35)S methionine and stained with silver. Internal amino acid sequencing identified five proteins among several proteins induced during appressorium formation. Two denoted as M. grisea proteasome homolgues (MgP1 and MgP5) were 20S proteasome alpha subunits. The remaining three were scytalone dehydratase (SCD), and serine carboxypeptidase Y (CPY). None of the five have been reported previously in the rice blast fungus apart from SCD. We further investigated the role the alpha subunit of 20S proteasome plays in appressorium formation. We confirmed by Western blot analysis that MgP5 is highly expressed during appressorium formation and found that it is also markedly induced by nitrogen- and carbon-starvation, in particular by the former. These observations suggest that the 20S proteasome may be involved in remobilizing storage proteins, which then help to build the appressorium. Thus, fungal proteome analysis may provide important clues about developmental changes such as the generation of the appressorium. 相似文献
12.
Plant Lipoxygenases (LOX) are known to play major role in plant immunity by providing front-line defense against pathogen-induced injury. To verify this, we isolated a full-length OsLOX3 gene and also 12 OsLOX cDNA clones from Oryza sativa indica (cultivar Pusa Basmati 1). We have examined the role played by LOXs in plant development and during attack by blast pathogen Magnaporthe grisea. Gene expression, promoter region analysis, and biochemical and protein structure analysis of isolated OsLOX3 revealed significant homology with LOX super family. Protein sequence comparison of OsLOXs revealed high levels of homology when compared with japonica rice (up to100%) and Arabidopsis (up to 64%). Isolated LOX3 gene and 12 OsLOX cDNAs contained the catalytic LOX domains much required for oxygen binding and synthesis of oxylipins. Amino acid composition, protein secondary structure, and promoter region analysis (with abundance of motifs CGTCA and TGACG) support the role of OsLOX3 gene in providing resistance to diseases in rice plants. OsLOX3 gene expression analysis of root, shoot, flag leaf, and developing and mature seed revealed organ specific patterns during rice plant development and gave evidence to association between tissue location and physiological roles played by individual OsLOXs. Increased defense activity of oxylipins was observed as demonstrated by PCR amplification of OsLOX3 gene and upon inoculation with virulent strains of M. grisea and ectopic application of methyl jasmonate in the injured leaf tissue in adult rice plants. 相似文献
13.
Cellular differentiation and host invasion by the rice blast fungus Magnaporthe grisea 总被引:3,自引:0,他引:3
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 function. Following entry to the host plant, new evidence suggests that M. grisea grows biotrophically within rice cells, bounded by the plant plasmalemma, and the fungus moves from cell-to-cell by means of plasmodesmata. Biotrophic proliferation of the fungus is likely to require secretion of effector proteins and suppression of host defences. Consistent with this, a component of the polarized exocytosis machinery of M. grisea is necessary for pathogenicity and also for induction of host defences in an incompatible interaction. Large-scale insertional mutagenesis is now allowing the rapid analysis of gene function in M. grisea, heralding a new approach to the study of this important fungal pathogen. 相似文献
14.
We report the cloning and characterisation of Pot2, a putative transposable element from Magnaporthe grisea. The element is 1857 by in size, has 43-bp perfect terminal inverted repeats (TIRs) and 16-bp direct repeats within the TIRs. A large open reading frame, potentially coding for a transposase-like protein, was identified. This putative protein coding region showed extensive identity to that of Fott, a transposable element from another phytopathogenic fungus, Fusarium oxysporum. Pot2, like the transposable elements Tc1 and Mariner of Caenorhabditis elegans and Drosophila, respectively, duplicates the dinucleotide TA at the target insertion site. Sequence analysis of DNA flanking 12 Pot2 elements revealed similarity to the consensus insertion sequence of Tct. Pot2 is present at a copy number of approximately 100 per haploid genome and represents one of the major repetitive DNAs shared by both rice and non-rice pathogens of M. grisea. 相似文献
15.
Summary. Microtubule dynamics were examined in live cells of the fungal plant pathogen Magnaporthe grisea transformed for constitutive expression of a fusion protein containing enhanced yellow-fluorescent protein and a Neurospora crassa benomyl-resistant allele of β-tubulin. Transformants retained their ability to differentiate appressoria and cause disease
but remained sensitive to benomyl. Linear microtubule arrays and low-level cytoplasmic fluorescence were observed in vegetative
hyphae, conidia, germ tubes, and developing appressoria. Fluorescence within nuclei was conspicuously absent during interphase
but increased rapidly at the onset of mitosis. Treatment with either benomyl or griseofulvin resulted in the appearance of
prominent brightly fluorescent aggregates, including a large aggregate near the apex, with the concomitant disappearance of
most cytoplasmic microtubules. Electron microscope imaging of treated cells indicated that the aggregates lacked any obvious
profiles of intact microtubules. During these treatments, hyphal tip cells continued to elongate in a nonlinear and aerial
fashion at a much slower rate than untreated cells. With subsequent removal of griseofulvin, distal aggregates disappeared
rapidly but the apical aggregates persisted longer. Treatment with latrunculin A caused hyphal tip swelling without apparent
effect on linear microtubule arrays. Simultaneous treatment with griseofulvin and latrunculin A resulted in depolymerization
of microtubules and a cessation of growth, but near-apical fluorescent aggregates were not observed.
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1007/s00709-004-0081-3
Correspondence and reprints: Department of Biological Sciences, University of Delaware, Newark, DE 19716, U.S.A.
Present address: Paradigm Genetics Inc., Research Triangle Park, North Carolina, U.S.A. 相似文献
16.
Soanes DM Kershaw MJ Cooley RN Talbot NJ 《Molecular plant-microbe interactions : MPMI》2002,15(12):1253-1267
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 utilization, NPR1 and NUT1, were required for full expression of MPG1 in response to starvation stress. The CPKA gene, encoding the catalytic subunit of protein kinase A, was required for repression of MPG1 during growth in rich nutrient conditions. During appressorium morphogenesis, high-level MPG1 expression was found to require the CPKA and NPR1 genes. Expression of a destabilized GFP allele indicated that de novo MPG1 expression occurs during appressorium formation. Three regions of the MPG1 promoter were identified which are required for high-level expression of MPG1 during appressorium formation and are necessary for the biological activity of the MPG1 hydrophobin during spore formation and plant infection. 相似文献
17.
Proteomic analysis of pathogen-responsive proteins from rice leaves induced by rice blast fungus, Magnaporthe grisea 总被引:12,自引:0,他引:12
Proteomic approaches using two-dimensional gel electrophoresis (2-DE) were adopted to identify proteins from rice leaf that are differentially expressed in response to the rice blast fungus, Magnaporthe grisea. Microscopic observation of inoculated leaf with M. grisea revealed that callose deposition and hypersensitive response was clearly visible in incompatible interactions but excessive invading hypha with branches were evident in compatible interactions. Proteins were extracted from leaves 24, 48, and 72 hours after rice blast fungus inoculation. Eight proteins resolved on the 2-DE gels were induced or increased in the inoculated leaf. Matrix-assisted laser desorption/ionization-time of flight analysis of these differentially displayed proteins showed them to be two receptor-like protein kinases (RLK), two beta-1.3-glucanases (Glu1, Glu2), thaumatin-like protein (TLP), peroxidase (POX 22.3), probenazole-inducible protein (PBZ1), and rice pathogenesis-related 10 (OsPR-10). Of these proteins, RLK, TLP, PBZ, and OsPR-10 proteins were induced more in the incompatible interactions than in compatible ones. A phytohormone, jasmonic acid also induced all eight proteins in leaves. To confirm whether the expression profile is equal to the 2-DE data, seven cDNA clones were used as probes in Northern hybridization experiments using total RNA from leaf tissues inoculated with incompatible and compatible rice blast fungal races. The genes encoding POX22.3, Glu1, Glu2, TLP, OsRLK, PBZ1, and OsPR-10 were activated in inoculated leaves, with TLP, OsRLK, PBZ1, and OsPR-10 being expressed earlier and more in incompatible than in compatible interactions. These results suggest that early and high induction of these genes may provide host plants with leading edges to defend themselves. The localization of two rice PR-10 proteins, PBZ1 and OsPR-10, was further examined by immunohistochemical analysis. PBZ1 accumulated highly in mesophyll cells under the attachment site of the appressorium. In contrast, OsPR-10 expression was mainly localized to vascular tissue. 相似文献
18.
Identification of a putative vacuolar serine protease gene in the rice blast fungus,Magnaporthe grisea 总被引:1,自引:0,他引:1
Fukiya S Kuge T Tanishima T Sone T Kamakura T Yamaguchi I Tomita F 《Bioscience, biotechnology, and biochemistry》2002,66(3):663-666
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. 相似文献
19.
Possible role of phytocassane,rice phytoalexin,in disease resistance of rice against the blast fungus Magnaporthe grisea 总被引:1,自引:0,他引:1
Umemura K Ogawa N Shimura M Koga J Usami H Kono T 《Bioscience, biotechnology, and biochemistry》2003,67(4):899-902
In addition to momilactone, phytocassanes A through E (diterpene phytoalexins) were detected in rice leaves in fields suffering from rice blast. Furthermore, phytocassane accumulation was most abundant at the edges of necrotic lesions, indicating that the phytoalexins prevent subsequent spread of the fungus from the infected site. In pot experiments the pattern of phytocassane accumulation in rice leaves in an incompatible interaction (infection with an avirulent race of Magnaporthe grisea) was more rapidly induced than in a compatible interaction (infection with a virulent race of M. grisea). 相似文献
20.
Transposon impala, a novel tool for gene tagging in the rice blast fungus Magnaporthe grisea 总被引:6,自引:0,他引:6
Villalba F Lebrun MH Hua-Van A Daboussi MJ Grosjean-Cournoyer MC 《Molecular plant-microbe interactions : MPMI》2001,14(3):308-315
impala, a Tc1-mariner transposable element from Fusarium oxysporum, was introduced into the rice blast fungus Magnaporthe grisea to develop transposon-based insertional mutagenesis. A construct (pNIL160) containing an autonomous impala copy inserted in the promoter of niaD encoding Aspergillus nidulans nitrate reductase was introduced by transformation into a M. grisea nitrate reductase-deficient mutant. impala excision was monitored by restoration of prototrophy for nitrate. Southern analysis of niaD+ revertants revealed that impala was able to excise and reinsert at new loci in M. grisea. As observed for its host Fusarium oxysporum, impala inserted at a TA site left a typical excision footprint of 5 bp. We have shown that a defective impala copy was inactive in M. grisea, yet it can be activated by a functional impala transposase. A transformant carrying a single copy of pNIL160 was used to generate a collection of 350 revertants. Mutants either altered for their mycelial growth (Rev2) or nonpathogenic (Rev77) were obtained. Complementation of Rev77 with a 3-kb genomic fragment from a wild-type locus was successful, demonstrating the tagging of a pathogenicity gene by impala. This gene, called ORP1, is essential for penetration of host leaves by M. grisea and has no sequence homology to known genes. 相似文献