抗性相关的小麦MYB转录因子的功能与作用机理的研究

项目名称： 抗性相关的小麦MYB转录因子的功能与作用机理的研究

项目编号： No.30871523

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 张增艳

作者单位： 中国农业科学院作物科学研究所

项目金额： 29万元

中文摘要： 克隆出1个新的抗性相关的小麦MYB基因TaPIMP1，其转录受根腐病菌、纹枯病菌和干旱等逆境的诱导，也受外源激素ABA、SA诱导，且后者应答快于前者。创制了转TaPIMP1基因小麦和烟草，分析其分子与功能，明确了TaPIMP1表达增强转基因烟草对青枯病、干旱、高盐、活性氧等逆境的抗性，TaPIMP1超量表达显著提高转基因小麦对根腐病、纹枯病、干旱等逆境的抗性，而TaPIMP1沉默显著降低转基因小麦对上述逆境的抗性。分子生物学分析证明小麦TaPIMP1蛋白是1个定位于细胞核的转录活化型的R2R3-MYB转录因子。从全基因组水平研究TaPIMP1调控的小麦基因表达谱，发现TaPIMP1显著上调一些逆境响应和防卫基因的转录，受干旱、根腐病菌、ABA-和SA-诱导。TaPIMP1作用机理假说：TaPIMP1是ABA-和SA-信号途径交互作用元件，转录激活这些路径上一些逆境响应和防卫基因，进而正向调控小麦对根腐病菌、纹枯病菌和干旱等的防御反应，为揭示小麦抗土传病和抗旱机制奠定基础，具较重要的理论与实践意义。发表SCI和核心刊论文4篇，另2篇SCI论文待发表。申请国家发明专利2项,培养研究生6名。

中文关键词： 小麦；MYB 转录因子；基因功能；抗性；调控机制

英文摘要： A full-length cDNA sequence of a MYB gene, namely TaPIMP1, was isolated from wheat. The TaPIMP1 transcript level was significantly up-regulated by infection of pathogens Bipolaris sorokiniana and Rhizoctonia cerealis, dehydration, and by phytohormones, ABA, and SA treatments. TaPIMP1 encodes the MYB protein TaPIMP1 consisting of 323 amino acids that is a new member of the R2R3-MYB transcription factor subfamily. The TaPIMP1 transgenic tobacco and wheat plants were generated and characterized by the transgene-molecular and functional assays. Compared to untransformed tobacco host plants, TaPIMP1 expressing plants displayed significantly enhanced resistance to the pathogen Ralstonia solanacearum, and increased tolerance to drought and salt stresses. Compared with untransformed wheat host plants, the transgenic wheat lines overexpressing TaPIMP1 exhibited an significantly-enhanced resistance to Bipolaris sorokiniana, Rhizoctonia cerealis, and drought stresses, whereas the TaPIMP1 RNAi transgenic wheat lines showed more susceptible to the stresses. Molecular-biology assays proved that TaPIMP1 is a trans-activator of R2R3-MYB transcription factor, localizes to the nucleus, binds specifically to MYB-recognition-element IIG, and possesses the transcriptional-activation capability. Microarray, bioinformics and Q-RT-PCR assays showed that a subset of stress-responsive genes were regulated by TaPIMP1, all of which were induced by B. sorokiniana, dehydration, abscisic acid (ABA) and salicylic acid (SA) treatments. The results suggest that TaPIMP1 is a transcriptional activator of these stress-responsive genes in ABA- and SA-signaling pathways, and TaPIMP1 mediates B. sorokiniana and drought resistance by regulating stress-responsive genes in wheat. TaPIMP1 will provide a tool for improving multiply-resistance in wheat and other cereal crops. Based on the research results, we published 4 scientific papers, including 1 SCI paper, 2 additional SCI manuscripts have been completed and will be published in the near future, and 2 national inventor patents related to the content have been awarded or applied. Two ph. D students and four master students were trained and gotten their degrees.

英文关键词： Wheat； R2R3 MYB transcription factor； gene function； resistance；regulational mechanism