title: Acetolactate synthases MoIlv2 and MoIlv6 are required for infection-related morphogenesis in Magnaporthe oryzae.
abstract: Amino acids are important components in the metabolism of a variety of pathogens, plants and animals. Acetolactate synthase (ALS) catalyses the first common step in leucine, isoleucine and valine biosynthesis, and is the target of several classes of inhibitors. Here, MoIlv2, an orthologue of the Saccharomyces cerevisiae ALS catalytic subunit Ilv2, and MoIlv6, an orthologue of the S. cerevisiae ALS regulatory subunit Ilv6, were identified. To characterize MoILV2 and MoILV6 functions, we generated the deletion mutants ΔMoilv2 and ΔMoilv6. Phenotypic analysis showed that both mutants were auxotrophic for leucine, isoleucine and valine, and were defective in conidial morphogenesis, appressorial penetration and pathogenicity. Further studies suggested that MoIlv2 and MoIlv6 play a critical role in maintaining the balance of intracellular amino acid levels. MoIlv2 and MoIlv6 are both localized to the mitochondria and the signal peptide of MoIlv6 is critical for its localization. In summary, our evidence indicates that MoIlv2 plays a crucial role in isoleucine and valine biosynthesis, whereas MoIlv6 contributes to isoleucine and leucine biosynthesis; both genes are required for fungal pathogenicity. This study indicates the potential of targeting branched-chain amino acid biosynthesis for anti-rice blast management.
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China; Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Du
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Hong
authors.forename: Jiamei
authors.initials: J
authors.lastname: Wang
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zheng
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000095:Acetolactate Synthase / Q000737:chemistry / Q000378:metabolism*; D000596:Amino Acids / Q000096:biosynthesis / Q000494:pharmacology; D053898:Biosynthetic Pathways / Q000187:drug effects; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D025301:Hyphae / Q000187:drug effects / Q000254:growth & development; D020082:Magnaporthe / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development* / Q000472:pathogenicity; D008969:Molecular Sequence Data; D009024:Morphogenesis / Q000187:drug effects; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D010858:Pigmentation / Q000187:drug effects; D010935:Plant Diseases / Q000382:microbiology*; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D013172:Spores, Fungal / Q000187:drug effects / Q000254:growth & development; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D005656:Fungal Proteins; D000095:Acetolactate Synthase