水稻作为世界上最重要的粮食作物之一，对其主要农艺性状调控机理的研究具有重要意义。水稻分蘖角度与植株地上部分的重力反应密切相关，是水稻株型的重要组成部分并对水稻产量有重要的贡献。本项目将通过全基因组表达谱测序技术，在基因组水平鉴定水稻分蘖角度调控基因，构建水稻分蘖角度动态调控的遗传和分子网络。同时通过遗传学、生物化学和分子生物学手段，鉴定控制水稻分蘖角度的关键因子LAZY1（LA1）的互作蛋白、蛋白复合体及抑制基因，通过系统的功能分析，揭示LA1介导的水稻分蘖角度调控网络。进一步挖掘不依赖于LA1介导的调控水稻分蘖角度新的功能基因和分子途径。综合上述研究，本项目以期系统揭示调控水稻分蘖角度的分子网络，并发现有应用价值的重要功能基因，为水稻株型改良提供重要的理论依据和可利用的基因资源。

Rice is the staple food for more than half the world’s population. The rice tiller angle, which is mainly determined by the shoot gravitropism, is a key agronomic trait for achieving ideal plant architecture and increasing grain yield. In this project, we are going to dissect the dynamic genetic and molecular basis of the control of rice tiller angle. We will use RNA-Seq technology to identify the genes involved in the regulation of shoot gravitropism and tiller angle, trying to reveal the molecular event and dynamic regulatory network of tiller angle at a whole genome level. Meanwhile, we are going to further elucidate the molecular pathway of LA1-mediated tiller angle by identification of LA1-interacted proteins, other candidates of LA1-complex, and the suppressors of la1. We will also attempt to use genetic and molecular approaches to identify new genes that act independently of LA1 in the tiller angle regulation. Combined these together, we are going to establish the molecular networks underlying rice tiller angle and to identify the potential genes applicable for improving the rice plant architecture and thus the grain yields.

水稻分蘖角度与植株地上部分的重力反应密切相关，是水稻株型的重要组成部分并对水稻产量有重要贡献。本项目在前期对水稻植株进行重力刺激并根据划分的时间点动态取材的基础上，获得了水稻茎重力反应过程中的动态转录组数据。通过深入分析，在全基因组水平上构建了水稻分蘖角度动态调控的分子网络，揭示了调控水稻分蘖角度的重要节点。同时，本项目对调控水稻分蘖角度的关键因子LAZY1的互作蛋白LAIP1进行了深入研究，发现LAIP1通过抑制LAZY1的核定位进而调控水稻的分蘖角度，为揭示LA1介导的水稻分蘖角度调控网络提供了重要信息。此外，本项目还从动态转录组数据及散生突变体中鉴定到5个通过重力反应调控水稻分蘖角度调控的新基因，并对它们进行了功能解析。本项目的研究成果为进一步挖掘调控水稻分蘖角度形成的新基因以及构建重力反应调控水稻分蘖角度形成的遗传调控网络奠定了基础。