玉米幼胚胚性愈伤组织诱导过程中重要miRNA及靶转录因子的功能研究

项目名称： 玉米幼胚胚性愈伤组织诱导过程中重要miRNA及靶转录因子的功能研究

项目编号： No.31271739

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 沈亚欧

作者单位： 四川农业大学

项目金额： 82万元

中文摘要： 幼胚胚性愈伤组织诱导是玉米转基因育种的重要技术环节，而我国具有高胚性愈伤诱导率的骨干自交系极少，阻碍了转基因玉米育种的快速发展。前期研究以高胚性愈伤诱导率自交系18-599R为材料，通过深度测序挖掘了4个在胚性愈伤诱导整个过程中急剧下调的miRNA家族，经靶基因预测结合数字表达谱分析和qRT-PCR验证结果，确定了3个转录因子作为以上4个miRNA家族的候选靶基因，而这3个转录因子基因在染色体上的位置与前期定位的胚性愈伤诱导率QTL位点是一致的。本项目拟首先采取5'RACE技术对miRNA剪切靶转录因子的精确位点进行鉴定；同时分别利用胚特异过表达和RNAi技术对以上miRNA和转录因子进行功能验证，获得控制玉米胚性愈伤诱导过程的miRNA和转录因子基因；并通过ChIP-Seq在全基因组水平上挖掘靶转录因子的互作基因，结合基因功能注释构建由miRNA介导的幼胚胚性愈伤诱导过程的分子调控网络。

中文关键词： 玉米幼胚；胚性愈伤组织；miRNA；转录因子；功能

英文摘要： Introduction of embryonic callus is an essential process in maize transgenic breeding. Low introduction efficiency for most of maize elite inbred lines prevents maize transgenic breeding from rapid development. In our previous study, the high-introduction effeiciency inbred line 18-599R was conducted to small RNA deep sequencing. As a result, 4 miRNA families were displayed to sharply down-regulated during the embryonic callus introduntion. Three transcript factors were respectively decided to be the candidate target genes of the four miRNAs by bioinformatic prediction and digital gene expression profiling. Further analysis revealed that the loci of the transcript factor genes is consistent with the QTL controlling the introduction of maize embryonic callus identified in the previous research. In the project, the accurate cutting site of target mRNA by the miRNAs will be identified using 5'RACE. The function of the miRNAs and targets involved in embryonic callus induction will be determined by embryo-spesific overexpression of the miRNAs and RNAi of the transcript factor genes. In addition, the interaction genes of the three transcript factors will be genome-widely revealed by ChIP-Seq technique. Then the regulatory network involved in the process of maize embryonic callus introduction will be constructed accord

英文关键词： Maize immature embryo；embryonic callus；miRNA；transcript factor；function