title: The wheat AGC kinase TaAGC1 is a positive contributor to host resistance to the necrotrophic pathogen Rhizoctonia cerealis.
abstract: Considerable progress has been made in understanding the roles of AGC kinases in mammalian systems. However, very little is known about the roles of AGC kinases in wheat (Triticum aestivum). The necrotrophic fungus Rhizoctonia cerealis is the major pathogen of the destructive disease sharp eyespot of wheat. In this study, the wheat AGC kinase gene TaAGC1, responding to R. cerealis infection, was isolated, and its properties and role in wheat defence were characterized. R. cerealis-resistant wheat lines expressed TaAGC1 at higher levels than susceptible wheat lines. Sequence and phylogenetic analyses showed that the TaAGC1 protein is a serine/threonine kinase belonging to the NDR (nuclear Dbf2-related) subgroup of AGC kinases. Kinase activity assays proved that TaAGC1 is a functional kinase and the Asp-239 residue located in the conserved serine/threonine kinase domain of TaAGC1 is required for the kinase activity. Subcellular localization assays indicated that TaAGC1 localized in the cytoplasm and nucleus. Virus-induced TaAGC1 silencing revealed that the down-regulation of TaAGC1 transcripts significantly impaired wheat resistance to R. cerealis. The molecular characterization and responses of TaAGC1 overexpressing transgenic wheat plants indicated that TaAGC1 overexpression significantly enhanced resistance to sharp eyespot and reduced the accumulation of reactive oxygen species (ROS) in wheat plants challenged with R. cerealis. Furthermore, ROS-scavenging and certain defence-associated genes were up-regulated in resistant plants overexpressing TaAGC1 but down-regulated in susceptible knock-down plants. These results suggested that the kinase TaAGC1 positively contributes to wheat immunity to R. cerealis through regulating expression of ROS-related and defence-associated genes.
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiuliang
authors.initials: X
authors.lastname: Zhu
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Yang
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xuening
authors.initials: X
authors.lastname: Wei
authors.affiliation: Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
authors.forename: Qiaofeng
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Rong
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Lipu
authors.initials: L
authors.lastname: Du
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Ye
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qi
authors.affiliation: The National Key Facility for Crop Gene Resources and Genetic Improvement, Key Laboratory of Biology and Genetic Improvement of Triticeae Crops, Ministry of Agriculture, Institute of Crop Science, Chinese Academy of Agricultural Sciences, Beijing 100081, China zhangzengyan@caas.cn.
authors.forename: Zengyan
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D057865:Plant Immunity; D010940:Plant Proteins; D012232:Rhizoctonia / Q000502:physiology*; D017422:Sequence Analysis, DNA; D014908:Triticum / Q000235:genetics* / Q000276:immunology / Q000382:microbiology
chemical_list: D010940:Plant Proteins
keywords: AGC kinase; Rhizoctonia cerealis; Triticum aestivum; differential expression; reactive oxygen species; resistance; wheat.