小麦“绿色革命”基因Rht-B1b降低株高的遗传调控机制解析

小麦矮秆基因Rht-B1b（Rht1）和Rht-D1b（Rht2）的广泛应用是“绿色革命”的重要标志，该基因在降低株高上的作用已经明确，但是其调控的下游基因还不清楚。为解决该问题，我们前期创制了Rht-B1b过表达（Rht-B1b-OE）和敲除（Rht-B1b-KO）材料，并用Rht-B1b-OE材料确认了Rht-B1b的一因多效性，完成了茎秆、种子、叶片关键时期的RNA-Seq 分析，为本项目奠定了良好工作基础。为深入解析Rht-B1b降低株高的遗传调控机制，本项目拟用Rht-B1b-OE、Rht-B1b-KO和阴性植株进行如下研究：（1）穗下节间基部的居间分生组织RNA-Seq分析和酵母双杂交筛选DELLA（Rht-B1b编码）互作蛋白，揭示基因的调控网络；（2）Rht-B1b下游关键基因功能验证；（3）在自然品种中挖掘、验证下游“关键基因”优异等位变异，开发方便育种应用的分子标记。

The extensively utilization of semi-dwarf genes Rht-B1b (Rht1) and Rht-D1b (Rht2) is an important symbol of the "Green Revolution" in wheat. Although the function of semi-dwarf genes Rht-B1b and Rht-D1b in reducing plant height has been well studied, their related genes and genetic network remain unclear. In order to solve these problems, we have created Rht-B1b gene over-expression (Rht-B1b-OE) and CRISPR/Cas9 knockout (Rht-B1b-KO) materials. The pleiotropic effects of Rht-B1b was confirmed using the Rht-B1b-OE materials by RNA sequencing (RNA-Seq) analysis of stems, seeds and leaves in key time-points, this work laid a good foundation for this on-going project. To further dissect the genetic regulation mechanism of Rht-B1b in reducing plant height, this project plans to use Rht-B1b-OE, Rht-B1b-KO and corresponding negative plants to carry out the following studies: (1) RNA-Seq analysis of basal meristem of uppermost internode and identification of DELLA (encoded by Rht-B1) interacting proteins by yeast two-hybrid system to disclose the gene regulatory network, (2) functional verification of Rht-B1b downstream genes, and (3) mining and verifying allelic variations of "key genes" in natural varieties, and developing molecular markers for marker-assisted breeding.