磷酸葡萄糖异构酶活性、结构、功能研究和定向改造

淀粉是人类生存所必需的能量来源，淀粉代谢是植物糖代谢、能量代谢的重要组成部分。因此对植物淀粉合成、代谢的研究具有重要的理论和现实意义。本项目结合结构生物学、生物化学、遗传学的研究手段，研究小麦淀粉合成代谢途径中关键酶6-磷酸葡萄糖异构酶（GPI）的基因组成、表达模式和蛋白性质；以细胞质型和叶绿体型GPI酶活性存在巨大差异为研究出发点，解析不同亚细胞定位的GPI蛋白的三维结构，分析影响它们酶活、结构和功能的关键氨基酸位点或结构域；探究影响GPI蛋白活性、结构和功能的作用机制。并试图通过改造GPI蛋白或改变GPI蛋白的定位，在体内改善植物淀粉合成、代谢效率，从而提升植物光合作用、糖代谢等途径的效率，最终提升植物的生物量乃至产量。本项目将进一步丰富植物淀粉合成、代谢途径及其调控因子的理论研究，为提高植物生物量或产量提供实验基础。

Starch synthesis and degradation is an important part in plant sugar and energy metabolism. Starch not only provides energy for human, but also is used other social activities of human, such as, healthcare, energy production, chemical industry, building industry, materials and other fields. Therefore, the research of starch metabolism pathway in plant has vital theoretical and practical significance. In this project, we use structural biology, biochemistry and genetics methods to study a key enzyme of glucose-6-phosphate isomerase (GPI) in starch metabolism in wheat. Here, we check the gene composition, expression patterns, and protein characters of GPIs; resolve different located GPIs’ 3-D structures; analysis the key amino acids or domains of GPI which may affect its activity, structures and functions; investigate the regulating mechanism of GPIs activity, structures and functions. In addition, we also try to modulate GPIs or change them location to improve the biological efficiency of plant photosynthesis, glucose metabolism and other metabolic pathways, and ultimately to improve plant biomass or yield. This project will further enrich the theoretical research on starch synthesis and degradation and its regulatory mechanism. It also provides the experimental basis for the improvement of plant biomass or yield.