title: A cytoplasmic Cu-Zn superoxide dismutase SOD1 contributes to hyphal growth and virulence of Fusarium graminearum.
abstract: Superoxide dismutases (SODs) are scavengers of superoxide radicals, one of the main reactive oxygen species (ROS) in the cell. SOD-based ROS scavenging system constitutes the frontline defense against intra- and extracellular ROS, but the roles of SODs in the important cereal pathogen Fusarium graminearum are not very clear. There are five SOD genes in F. graminearum genome, encoding cytoplasmic Cu-Zn SOD1 and MnSOD3, mitochondrial MnSOD2 and FeSOD4, and extracellular CuSOD5. Previous studies reported that the expression of SOD1 increased during infection of wheat coleoptiles and florets. In this work we showed that the recombinant SOD1 protein had the superoxide dismutase activity in vitro, and that the SOD1-mRFP fusion protein localized in the cytoplasm of F. graminearum. The Δsod1 mutants had slightly reduced hyphal growth and markedly increased sensitivity to the intracellular ROS generator menadione. The conidial germination under extracellular oxidative stress was significantly delayed in the mutants. Wheat floret infection assay showed that the Δsod1 mutants had a reduced pathogenicity. Furthermore, the Δsod1 mutants had a significant reduction in production of deoxynivalenol mycotoxin. Our results indicate that the cytoplasmic Cu-Zn SOD1 affects fungal growth probably depending on detoxification of intracellular superoxide radicals, and that SOD1-mediated deoxynivalenol production contributes to the virulence of F. graminearum in wheat head infection.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; School of Life Science, East China Normal University, Shanghai 200062, China.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Yao
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Guo
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yan-Zhang
authors.initials: YZ
authors.lastname: Wang
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: School of Life Science, East China Normal University, Shanghai 200062, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address: whtang@sibs.ac.cn.
authors.forename: Wei-Hua
authors.initials: WH
authors.lastname: Tang
mesh_terms: D003593:Cytoplasm / Q000201:enzymology; D005670:Fusarium / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity; D025301:Hyphae / Q000235:genetics / Q000254:growth & development; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics*; D018384:Oxidative Stress / Q000235:genetics*; D017382:Reactive Oxygen Species / Q000378:metabolism; D000072105:Superoxide Dismutase-1 / Q000235:genetics* / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014908:Triticum / Q000382:microbiology
chemical_list: D017382:Reactive Oxygen Species; D013481:Superoxides; D000072105:Superoxide Dismutase-1
keywords: Cu-Zn SOD1; Deoxynivalenol; Fusarium graminearum; Hyphal growth; Pathogenicity; Reactive oxygen species (ROS)