小麦(Triticum aestivum L.)是我国北方主要粮食作物，进一步提高小麦产量潜力是我国农业发展亟待解决的重要问题。前期工作利用反向遗传学方法，通过构建六倍体小麦突变群体，筛选获得不同染色体组谷氨酰胺合成酶基因(TaGS2)缺失突变体（gs2-a、gs2-b、gs2-d），通过不同染色体组单突变体间杂交获得了双重突变体（gs2-a/gs2-b、gs2-b/gs2-d、gs2-a/gs2-d）。分析结果表明，TaGS2基因缺失引起叶片黄化，穗数减少、穗粒数降低，籽粒产量下降。本课题将在此基础上开展：TaGS2表达量与籽粒产量的关系；TaGS2对光合作用、氮效率的影响；TaGS2参与光呼吸过程，调控相关基因表达、活性氧积累及抗氧化酶类的活性分析，最终从氮代谢与光呼吸两个方面揭示TaGS2基因调控小麦籽粒产量的作用机制。

Wheat (Triticum aestivum l.) is a major crop in north China, improve the wheat yield potential is an important problem urgently to be solved in the agricultural development of our country. Previous work using the reverse genetic approaches, a series of glutamine synthetase (TaGS2) knockout mutants (gs2-a、gs2-b、gs2-d) and their derivative double mutants (gs2-a/gs2-b、gs2-b/gs2-d、gs2-a/gs2-d) were obtained for three TaGS2 homoeologous genes in hexaploid wheat. Under normal condition, TaGS2 double mutants developed a severe chlorotic phenotype, have fewer spikes, lower spike kernels than wild type and eventually led to reduced grain yield. In this project, we try to analyze the relationship between the TaGS2 genes expression with grain yield; photosynthesis and nitrogen metabolism. Moreover, our research will focus on the regulation of photorespiration-related genes expression, reactive oxygen species (ROS) accumulation and antioxidant enzyme activity through plant physiology and molecular biology approaches. Eventually, we will uncover the mechanism of TaGS2 affected grain yield from two aspects of nitrogen metabolism and photorespiration.