OsmiR160-OsARFs调控水稻分蘖角度的机制研究

分蘖角度是水稻理想株型的重要组成部分，但目前尚未建立完整的遗传调控网络，尤其关于microRNA(miRNA)调控水稻分蘖角度的研究依然很少。本项目前期通过过量表达OsmiR160首次发现其正调控水稻分蘖角度，时空表达谱分析表明它在感受重力的组织中表达较高；经降解组测序鉴定到4个靶基因OsARF8、OsARF10、OsARF18和OsARF22。本项目将围绕解析OsmiR160-OsARFs对水稻分蘖角度的调控机制展开，包括：1）STTM和CRISPR抑制OsmiR160对水稻分蘖角度的作用；2）通过CRISPR敲除和OsARFs的miRNA靶点突变验证靶基因功能；3）OsmiR160和OsARFs遗传材料的向重力性分析，与植物激素的互作分析，以及通过RNA seq等分析其下游调控网络。本研究将完善对水稻分蘖角度转录后调控机制的认识，也为水稻的株型改良和合理密植提供新思路和指导意义。

Tiller angle is one of the most important components of the ideal plant architecture. However, the complete genetic regulatory network has not yet been established, especially the study of microRNA(miRNA) in regulating rice tiller angle is still rare. We found for the first time that OsmiR160 could positively regulate rice tiller angle in OsmiR160 overexpression transgenic lines. Spatial-temporal expression pattern analysis showed that OsmiR160 had relatively higher expression levels in gravity sensitive tissues; Four target genes, OsARF8, OsARF10, OsARF18 and OsARF22, were identified by degradome sequencing. This project will focus on the molecular mechanism of OsmiR160-OsARFs interaction in regulating rice tiller angle on three aspects, including: 1）elucidating the function of OsmiR160 in rice tiller angle by inhibiting its expression using STTM and CRISPR technologies; 2) confirming the roles of target genes using CRISPR knockout and miRNA target mutation of OsARFs; 3) performing gravitropism analysis of genetic materials of OsmiR160 and OsARFs , interaction analysis between phytohormone and OsmiR160-OsARFs, and analysis of OsmiR160-OsARFs downstream targets in regulatory network by RNA seq etc. This study will improve the understanding of post-transcriptional regulation mechanism in rice tiller angle, and provide new ideas and guidance for improving plant type and rational close planting of rice.