miRNA是一类重要的调节内源基因表达的调控因子，广泛参与植物的生长发育。旗叶对小麦生殖器官的发育及小麦产量有极为重要的作用。最近，我们在小偃6号小麦中鉴定出旗叶偏爱性高表达miRNA，它们如何调控旗叶的生长发育及小麦品质产量尚不清楚。在前期研究的基础上，本项目重点研究2个小麦旗叶偏爱性高表达的新miRNA（tae-miR5048和tae-miR9663）的功能。拟对旗叶的RNA降解组进行高通量测序，确定候选miRNA的靶基因；分离克隆miRNA及其靶基因序列；实验验证miRNA及其靶基因的表达模式；利用病毒诱导小麦旗叶內源基因沉默和转基因过表达进行候选miRNA和靶基因的功能鉴定。本项目将揭示候选miRNA对旗叶生长发育的调控作用及调控方式，并希望能鉴定出在小麦优质高产育种上具有应用价值的miRNA或靶基因。

miRNAs are essential regulators which regulate gene expression and are involved in plant growth and development. Flag leaves play important roles in the development of wheat reproductive organs and wheat yield. We have identified some novel miRNAs which highly express in flag leaves in wheat cv. Xiaoyan6, but how they regulate the growth and development of flag leaves and how they have impacts on wheat quality and yield remain unclear. According to our previous research, our project aims to focus on the functions of 2 miRNA (tae-miR5048 and tae-miR9663) which highly express in flag leaves. RNA degradom from wheat flag leaves will be deeply sequenced by high-throughput to determine the candidate target mRNAs of miRNA. The pre-miRNA sequences and the miRNA target genes will be cloned. The expression pattern of miRNAs and their targets will be examined. The biological functions of these two miRNAs and their target genes will be identified by two approaches, i.e. VIGS of wheat seed-specific gene expression and wheat transgenic overexpression.