蛋白质是稻米中仅次于淀粉的第二大物质，其含量和组成直接影响稻米的品质。谷蛋白是稻米中最主要的储藏蛋白，因此，对谷蛋白合成、转运和积累的研究将有助于稻米蛋白品质的改良。前期研究中我们利用筛选到的谷蛋白前体增加突变体，已经克隆获得了控制谷蛋白成熟的关键基因OsVPE1，控制谷蛋白后Golgi体运输关键基因GPA1/OsRab5a、GAP2/OsVPS9a和GPA3/OsKelch1，并对它们的功能进行了部分阐述。最近，我们利用两个等位的新谷蛋白前体增加突变体克隆获得了控制谷蛋白ER-Golgi体正向运输关键基因GPA4/OsGot1。本项目拟通过对OsGot1的功能研究，基本明晰OsGot1调控谷蛋白ER-Golgi正向运输的分子机制，为最终阐明谷蛋白合成、转运和积累的网络途径奠定基础，也为稻米蛋白品质的改良提供可靠的理论支撑。

Protein is the second-largest component in rice in addition to starch. The content and composition of protein affects rice quality directly. Glutelins are the major storage protein in rice. Therefore, dissection of the biosynthesis, transport, and accumulation of glutelins is of useful for rice protein quality improvement. Our previous studies have identified several key factors involved in glutelin trafficking and accumulation process, including OsVPE1, which plays an essential role in the maturation of glutelin, GPA1/OsRab5a, GAP2/OsVPS9a, and GPA3/OsKelch1, which control post-Golgi trafficking of glutelins. Recently, using two allelic glutelin precursor accumulation mutants, we isolated a novel key factor involved in controlling the anterograde transport of glutelins between ER and Golgi apparatus. This project will try to elucidate the molecular mechanisms of OsGot1 in regulation of the ER-Golgi anterograde transport, which will lay a foundation for elucidating the glutelin trafficking pathway. And in turn provides theoretical directions for further protein quality improvement in rice.