制约草坪观赏质量的主要因素是水分和氮营养。通过基因改良草地早熟禾耐旱和耐氮素贫瘠特性，从而提高水肥利用效率，是创新这一世界著名草坪草新种质及节约资源和环境友好的重要途径。项目组前期研究发现草地早熟禾叶绿体型谷氨酰胺合成酶PpGS2基因具有响应不同水氮条件并参与调解草地早熟禾氮代谢及耐旱和耐低氮能力的功效，然而其作用机理尚不明确。本项目基于前期研究基础，拟进一步通过基因超表达和敲除技术对草地早熟禾的PpGS2基因调控氮代谢和抗旱性的功能进行系统研究，测定植株表型特征、生理代谢和重要相关基因的表达，以揭示其基因功能和调控机制。研究成果可为培育和创新我国草地早熟禾草坪新品种提供理论依据和技术支撑。

Water and nitrogen as the most important factors limit the ornamental quality of turfgrass. An effective innovation strategy for water and nitrogen resource conservation and environmental friendly is using genetic methods to improve the drought resistance and lower nitrogen tolerance of the world famous Kentucky bluegrass, and further to enhance its water and nitrogen use efficiency. Former study in our group revealed that the gene of chloroplastic glutamine synthetase PpGS2 possessed the unique functions in regulating nitrogen metabolism and drought resistance as well as lower nitrogen tolerance of Kentucky bluegrass in response to different water and nitrogen conditions. However, these involving mechanisms were not clear. In this study, molecular techniques of gene overexpression and gene knockout will be used for transgenic the gene PpGS2 to different genotypes of Kentucky bluegrass. Measurements on the transgenic plants phenotypic traits, the physiological attributes, some important water-nitrogen relation genes expression are included and will be used for further revealing the functions and regulating mechanism of the PpGS2. The results of this research will be important to support the genetically innovation of new Kentucky bluegrass cultivars in China.