尼瓦拉野生稻半匍匐生长习性基因SPROG1克隆及其分子机理研究

水稻分蘖角度是影响株型的重要因素之一。匍匐生长习性是野生稻进化为栽培稻的主要驯化性状之一，是由基因控制的。因此，野生稻是水稻分蘖角度基因发掘的宝贵资源。本项目组在前期研究中，利用尼瓦拉野生稻为供体的单片段代换系鉴定出一个新的野生稻半匍匐生长习性基因SPROG1，利用F2分离群体已将其精细定位在11号染色体短臂7.2kb的区间内，此区间包含2个候选基因。本项目拟在此基础上，开展以下研究：克隆SPROG1基因，并进行基因功能分析；通过SPROG1基因表达分析、原位杂交、亚细胞定位、互作蛋白筛选、以及与其它分蘖角度相关基因的遗传互作关系分析等，解析SPROG1调控野生稻半匍匐生长的作用机理；利用栽培稻品种和野生稻鉴定SPROG1基因的等位变异，解析其分子进化机制。SPROG1基因的克隆有助于从分子水平解析野生稻半匍匐生长习性的遗传基础，并为水稻分蘖角度基因发掘及株型分子育种提供参考。

Tillering angle is one of the important factors affecting rice plant architecture. Prostrate growth habit is one of the major traits for domestication of cultivated rice from wild rice and is a genetic character. So wild rice species is the valuable germplasm resources for mining the genes related to rice tillering angle. In the previous study, we identified a novel gene, SPROG1, which controlling semi-prostrate growth habit of wild rice, in the single segment substitution lines (SSSLs) of O. nivara in the background of cultivar, HJX74. By using a F2 population, SPROG1 was delimited to a physical region of 7.2kb on the short arm of chromosome 11, and two candidate genes were included at the interval. In this study, we will further clone the SPROG1 gene and identify its function; and reveal its molecular mechanism of regulating semi-prostrate growth habit of wild rice by the experiments of gene expression analysis, in situ hybridization, subcellular localization and interaction protein screening，as well as analyzing of the genetic interaction of SPROG1 with other genes related to tillering angle by developing pyramiding lines. Then we plan to analyze the allelic variations of SPROG1 between the wild rice species and cultivars during rice domestication. Taken together, the results in this study will not only be helpful in elucidating the genetic bases of the semi-prostrate growth habit of wild rice species at the molecular level, but also will provide an important reference for the gene exploring of tillering angle and molecular breeding of plant architecture in rice.