蛋白磷酸酶2A催化亚基OSPP13调控水稻雄性不育的机理研究

水稻雄性不育是影响水稻产量的关键因子之一。雄性不育突变体是研究水稻花粉发育机制的理想材料。本项目前期发现一个水稻雄性不育突变体ospp13(protein phosphatase 13)，并将该OSPP13基因精细定位在水稻第1染色体上约52-kb的区间内。对该区域测序发现该突变体在第6个开放阅读框（ORF）的编码区存在一个单碱基突变，导致蛋白翻译的提前终止。通过功能互补验证，证实ORF6是OSPP13的目的基因，该基因编码一个水稻蛋白磷酸酶2A(PP2A)。系统进化分析表明OSPP13蛋白属于PP2A蛋白的催化亚基C分支。本研究将通过进一步观察该突变体小孢子减数分裂过程中染色体行为和纺锤体的形成、分析OSPP13的时空表达模式、研究亚细胞定位特性、确定OSPP13基因在花粉发育调控网络中的位置,筛选并验证其互作蛋白，揭示OSPP13蛋白调控水稻雄性不育的机制。

Pollen sterility is crucial for rice yield and male-sterile mutants are ideal materials for studying the molecular mechanism of pollen development in rice. In previous research, we found a rice mutant ospp13(protein phosphatase 13) which exhibited complete male sterility. Through fine mapping, OSPP13 was restricted to a 52-kb region on rice chromosome 1. By sequencing the entire region, a single nucleotide conversion was found in the coding region of ORF6, which caused early termination. By using complementary test, we confirmed that ORF6 corresponds to the OSPP13 gene and encodes a protein phosphatase 2A. Phylogenetic analysis showed that OSPP13 protein belonged to the catalytic subunit C group of PP2A protein. In order to reveal the genetic mechanism and molecular regulation role of OSPP13 protein in male sterility, we will observe the chromosome behavior and spindle formation in male meiosis, analyze the spatial and temporal expression pattern of OSPP13, investigate the subcellular localization of OSPP13 protein, point out the function of OSPP13 in regulating pollen development network, and verify direct interactive proteins.