title: Regulation of the MPG1 hydrophobin gene in the rice blast fungus Magnaporthe grisea.
abstract: 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.
authors.affiliation: School of Biological Sciences, University of Exeter, Washington Singer Laboratories, Perry Road, Exeter, EX4 4QG, UK.
authors.forename: Darren M
authors.initials: DM
authors.lastname: Soanes
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kershaw
authors.forename: R Neil
authors.initials: RN
authors.lastname: Cooley
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Talbot
mesh_terms: D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D020082:Magnaporthe / Q000235:genetics* / Q000254:growth & development / Q000648:ultrastructure; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; C066958:NPR1 protein, S cerevisiae; D011494:Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C102726:Pmk1 protein, Magnaporthe grisea