title: Genome-Wide Analysis of Hypoxia-Responsive Genes in the Rice Blast Fungus, Magnaporthe oryzae.
abstract: Rice blast fungus, Magnaporthe oryzae, is the most destructive pathogen in the rice-growing area. This fungus has a biotrophic phase early in infection and later switches to a necrotrophic lifestyle. During the biotrophic phase, the fungus competes with its host for nutrients and oxygen. Continuous uptake of oxygen is essential for successful establishment of blast disease of this pathogen. Here, we report transcriptional responses of the fungus to oxygen limitation. Transcriptome analysis using RNA-Seq identified that 1,047 genes were up-regulated in response to hypoxia. Those genes are involved in mycelial development, sterol biosynthesis, and metal ion transport based on hierarchical GO terms, and are well-conserved among three fungal species. In addition, null mutants of two hypoxia-responsive genes were generated and their roles in fungal development and pathogenicity tested. The mutant for the sterol regulatory element-binding protein gene, MoSRE1, exhibited increased sensitivity to a hypoxia-mimicking agent, increased conidiation, and delayed invasive growth within host cells, which is suggestive of important roles in fungal development. However, such defects did not cause any significant decrease in disease severity. The other null mutant, for the alcohol dehydrogenase gene MoADH1, showed no defect in the hypoxia-mimicking condition (using cobalt chloride) and fungal development. Taken together, this comprehensive transcriptional profiling in response to a hypoxic condition with experimental validations would provide new insights into fungal development and pathogenicity in plant pathogenic fungi.
authors.affiliation: Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon 406-772, Korea.
authors.forename: Jaehyuk
authors.initials: J
authors.lastname: Choi
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea.
authors.forename: Hyunjung
authors.initials: H
authors.lastname: Chung
authors.affiliation: Fungal Bioinformatics Laboratory, Seoul National University, Seoul 151-921, Korea.
authors.forename: Gir-Won
authors.initials: GW
authors.lastname: Lee
authors.affiliation: Department of Biochemistry, Paichai University, Daejeon 302-735, Korea.
authors.forename: Sun-Ki
authors.initials: SK
authors.lastname: Koh
authors.affiliation: Department of Biochemistry, Paichai University, Daejeon 302-735, Korea.
authors.forename: Suhn-Kee
authors.initials: SK
authors.lastname: Chae
authors.affiliation: Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Korea; Fungal Bioinformatics Laboratory, Seoul National University, Seoul 151-921, Korea; Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Korea; Center for Fungal Genetic Resources, Seoul National University, Seoul 151-921, Korea; Plant Genomics and Breeding Institute, Seoul National University, Seoul 151-921, Korea; Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Lee
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics; D015687:Cell Hypoxia / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D063990:Gene Ontology; D005800:Genes, Fungal; D055106:Genome-Wide Association Study; D020082:Magnaporthe / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D009154:Mutation; D012275:Oryza / Q000382:microbiology*; D018384:Oxidative Stress; D010100:Oxygen / Q000494:pharmacology; D012331:RNA, Fungal / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D013045:Species Specificity; D051779:Sterol Regulatory Element Binding Proteins / Q000235:genetics; D059467:Transcriptome; D014170:Transformation, Genetic; D014774:Virulence / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D012331:RNA, Fungal; D012333:RNA, Messenger; D051779:Sterol Regulatory Element Binding Proteins; D000426:Alcohol Dehydrogenase; D010100:Oxygen