元江普通野生稻孕穗期耐热性主效QTL(qHTB1-1)图位克隆及功能分析

我国长江流域稻区高温热害频发，目前生产上主栽水稻品种遗传基础狭窄，尤其生殖发育阶段耐热性普遍较差。将高温耐受性好的野生稻有利基因转移至栽培稻是耐热性遗传改良的主要途径。本申请项目前期完成了元江普通野生稻（HHT4）孕穗期耐热性主效QTL(qHTB1-1)的精细定位，并通过对区间内预测ORFs进行高温诱导表达分析，鉴定了2个高温胁迫响应的候选基因。本申请项目将在此基础上，通过图位克隆策略进一步克隆孕穗期耐热性主效基因，并通过功能互补、过量表达和基因敲除验证qHTB1-1基因的功能。利用酵母双杂交筛选互作蛋白并验证，同时测定qHTB1-1转基因植株高温胁迫下互作蛋白含量的差异，分析其生物学功能。结合表达模式和生物信息学分析初步解释其分子机理。本项目的完成不仅对阐明水稻孕穗期花粉动态发育过程中高温胁迫敏感期耐热机制具有重要的理论意义，而且对水稻耐热育种及水稻的安全生产也将具有十分重要的应用价值。

High temperature stress happened frequently over rice growing area of the Yangtze River Valley in China. At present, the heat tolerance genetic basis of the main rice varieties is narrow, especially the heat tolerance at the reproductive stage are generally weak. It is a major way to transfer wild rice heat tolerance genes into cultivated rice for improving the heat tolerance. In this study, we have fine-mapped a major QTL(qHTB1-1) conferring heat tolerance at the booting stage from Yuanjiang Common Wild Rice(HHT4). We will clone candidate gene of qHTB1-1 through map-based method, and clarify the relationship between spikelet fertility development and high temperature tolerance through the functional complementation analysis, over expression and CRISPR/Cas9. At the same time, we will further screen and identify qHTB1-1 interacting proteins by yeast two-hybrid assay, and compare the accumulation of interacting proteins in qHTB1-1 transgenic plants. We will preliminarily explained the molecular mechanism by combining expression pattern and bioinformatics analysis.The implementation of this application, it will be significant not only to the research on basic theory of high temperature tolerance mechanism of sensitive period during rice pollen dynamic development at the booting stage, but also application value in rice breeding for heat tolerance and rice production security.