title: The Magnaporthe grisea snodprot1 homolog, MSP1, is required for virulence.
abstract: Secreted proteins play central roles in plant-microbe interactions acting as signals, toxins, and effectors. One important group of small secreted proteins is the snodprot1 family, members of which have demonstrated phytotoxic properties. A split-marker transformation system was applied for gene deletion of the snodprot1 homolog, MSP1, in the rice blast fungus Magnaporthe grisea. msp1 mutants were phenotypically indistinguishable from wild type and elaborated apparently normal appressoria. However, the deletion mutants were greatly reduced in virulence primarily due to impaired growth in planta. Western blot analysis showed that the protein was secreted and not associated with the fungal cell wall. When purified MSP1 protein was applied to wounded leaf tissue, no apparent phytotoxic effects were noted. This is the first report to the authors' knowledge that directly implicates a snodprot1 protein as a virulence factor.
authors.affiliation: Department of Plant Pathology, Center for Integrated Fungal Research (CIFR), North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Jun Seop
authors.initials: JS
authors.lastname: Jeong
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Mitchell
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Dean
mesh_terms: D015153:Blotting, Western; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D001467:Hordeum / Q000382:microbiology; D020082:Magnaporthe / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D008969:Molecular Sequence Data; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
chemical_list: D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors