ABC1激酶基因OsABC1K8调控水稻种子大小的分子机制

水稻是重要的粮食作物，种子大小是决定水稻产量的最重要因素之一。研究水稻种子大小调控的分子机制，对于解析水稻种子发育机理以及通过分子育种提高水稻产量具有重要意义。ABC1（Activity of bc1 complex）激酶是近年来新发现的一类蛋白质激酶，主要分布在植物叶绿体及线粒体内。我们前期通过突变体分析和过表达证明，水稻叶绿体ABC1激酶基因OsABC1K8对种子大小具有显著的调控作用，但该基因调控水稻种子大小的生理生化及分子机制尚不清楚。本项目拟以已经获得的OsABC1K8突变体、过表达和启动子-GUS株系为材料，利用组织学和生理学手段深入阐明OsABC1K8调控水稻种子发育的生理机制，并通过RNA-seq转录组测序结合酵母双杂交筛选互作蛋白鉴定该基因的作用网络。以期阐明OsABC1K8控制水稻粒形的分子机理，为分子育种提供新基因资源，同时也为解析作物种子发育的遗传机理提供理论依据。

Rice is one of the most important food crops worldwide. Seed size is a key determinant of rice yield. To study the molecular mechanisms underlying regulation of rice seed size is extremely important for both genetic dissection of rice seed development and molecular breeding to improve rice yield. ABC1 (Activity of bc1 complex) kinases are newly found protein kinases, which are mainly located in chloroplasts or mitochondria in plants. In previous studies, we demonstrated that the chloroplast ABC1-kinase gene, OsABC1K8, is a key regulator of rice seed size by mutant analysis and over-expression (OE) assay. However, the physiological, biochemical and molecular mechanisms by which the gene controls rice seed size is still unknown. In this project, we will deep investigate the physiological mechanism by which OsABC1K8 modulates rice seed development using obtained mutant, OE and promoter-GUS plants and histological and physiological approaches, and identify the regulation network of the gene by RNA-seq analysis in combined with yeast two-hybrid screening. Our task is to illustrate the molecular mechanism by which OsABC1K8 controls rice grain shape, and provide new gene resources for rice high-yield molecular breeding. This study will also help to dissect the genetic mechanisms underlying crop seed development.