title: Role of the MoYAK1 protein kinase gene in Magnaporthe oryzae development and pathogenicity.
abstract: Conidiation and appressorium differentiation are key processes for polycyclic dissemination and infection in many pathogens. Our previous study using DNA microarray led to the discovery of the MoYAK1 gene in Magnaporthe oryzae that is orthologous to YAK1 in Saccharomyces cerevisiae. Although the mechanistic roles of YAK1 in S. cerevisiae have been described, roles of MoYAK1 in M. oryzae, a phytopathogenic fungus responsible for rice blast, remain uncharacterized. Targeted disruption of MoYAK1 results in pleiotropic defects in M. oryzae development and pathogenicity. The ΔMoyak1 mutant exhibits a severe reduction in aerial hyphal formation and conidiation. Conidia in the ΔMoyak1 are delayed in germination and demonstrate decreased glycogen content in a conidial age-dependent manner. The expression of hydrophobin-coding genes is dramatically changed in the ΔMoyak1 mutant, leading to a loss of surface hydrophobicity. Unlike the complete inability of the ΔMoyak1 mutant to develop appressoria on an inductive surface, the mutant forms appressoria of abnormal morphology in response to exogenous cyclic adenosine-5'-monophosphate and host-driven signals, which are all defective in penetrating host tissues due to abnormalities in glycogen and lipid metabolism, turgor generation and cell wall integrity. These data indicate that MoYAK1 is a protein kinase important for the development and pathogenicity of M. oryzae.
authors.affiliation: Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, 200-701, South Korea.
authors.forename: Joon-Hee
authors.initials: JH
authors.lastname: Han
authors.affiliation: Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, 200-701, South Korea.
authors.forename: Hye-Min
authors.initials: HM
authors.lastname: Lee
authors.affiliation: Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, 200-701, South Korea.
authors.forename: Jong-Hwan
authors.initials: JH
authors.lastname: Shin
authors.affiliation: Department of Agricultural Biotechnology, Center for Fungal Genetic Resources, Center for Fungal Pathogenesis, Plant Genomics and Breeding Institute, Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Korea.
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Applied Biology, College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, 200-701, South Korea.|BioHerb Research Institute, Kangwon National University, Chuncheon, 200-701, South Korea.
authors.forename: Kyoung Su
authors.initials: KS
authors.lastname: Kim
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology; D005656:Fungal Proteins / Q000235:genetics; D017353:Gene Deletion; D005800:Genes, Fungal; D006003:Glycogen / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D025301:Hyphae / Q000254:growth & development; D020082:Magnaporthe / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D012275:Oryza / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D013172:Spores, Fungal / Q000254:growth & development; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D006003:Glycogen; D000242:Cyclic AMP; D011494:Protein Kinases