谷氨酰胺合成酶（GS）是植物氮代谢过程中的关键酶，酶活性的高低影响农作物对氮素的利用和许多重要农艺性状。目前对小麦的研究，仅限于GS酶活性与氮效率和农艺性状之间的表型相关和QTL连锁分析，还缺乏遗传学证据。我们此前的研究发现小麦基因组中共有3个GS2成员，分别位于2A、2B和2D染色体，各有2、6和2种单元型；并通过关联分析获得了与氮素利用和农艺性状关联的优良单元型。在此基础上，本项目主要研究：（1）TaGS2不同成员和单元型的酶活性差异；（2）TaGS2不同成员和单元型的时空表达特性差异；（3）TaGS2不同成员和单元型对小麦吸收利用氮素和农艺性状的影响。本研究对于深入理解GS2在小麦氮素利用中的作用具有非常重要的意义，也可为小麦进一步的遗传改良提供理论依据和基因资源。

Glutamine synthetase (GS) is a key enzyme in nitrogen metabolism. The enzyme activities level of GS affects the nitrogen utility efficiency (NUE) and many important agronomic traits in crop. Up to now the study on GS in wheat is only limited in the field of QTLs and the phenotypic correlation between enzyme activities and NUE and agronomic traits. The genetic evidence is poor. Our previous studies have shown here are three members of TaGS2 in genome of wheat which are localized on chromosome 2A、2B and 2D, respectively. The number of TaGS2 haplotypes for TaGS2-A1、TaGS2-B1 and TaGS2-D1 is 2, 6 and 2, respectively. We have identified some good haplotypes variety of TaGS2 by analyzing their association with N use and agronomic traits in wheat. Based on above research results, the project focused on: (1) the difference between enzyme activities of each TaGS2 member and haplotype; (2) the difference between spatiotemporal expression patterns of TaGS2 haplotypes; (3) the effects of TaGS2 haplotype on NUE and agronomic traits in wheat. The project is significant to full understanding the functional properties of TaGS2 in NUE of wheat and also might provide theoretical basis and gene resources for further genetic improvement of wheat.