赤霉素（GA）和氮（N）在植物生长发育过程中都起到非常重要的作用。但赤霉素与植物氮吸收之间的关系目前研究还很少，我们前期实验结果发现赤霉素能够促进根部NRT2.1的表达以及根系对NO3-的吸收，但赤霉素如何调控植物氮吸收的分子机制还不清楚。本项目拟以拟南芥和小麦为研究材料，寻找获得与赤霉素信号转导中关键抑制因子DELLA蛋白互作并结合NRT2.1启动子的转录因子GIP1 (GAI-interacting protein 1)；明确DELLA与GIP1之间的遗传关系，进一步明确DELLA与GIP1互作如何影响植物NO3-的吸收，最终建立DELLA-GIP1调控植物氮吸收的分子模型。本项目研究结果不仅能够增加我们对赤霉素调控植物氮吸收分子机制的认识，并且为提高“第一次绿色革命”中矮秆作物氮肥吸收利用效率、进一步提高粮食产量以及氮肥过量施用带来的生态等方面问题的解决提供具有科学价值的理论参考。

Gibberellic acid (GA) and nitrogen (N) play very important roles in the process of plant growth and development. But the relationship between GA and N uptake is still unclear. Our preliminary experiment results show that GA can upregulate the expression of nitrate transporter gene NRT2.1 and promote the plant nitrate uptake, but the molecular mechanism how GA regulate plant N uptake is unknown. In this study, we will use Rht1 wheat and gibberellin-associated arabidopsis mutants as research materials: 1, to screen GAI interacting protein 1 (GIP1) which can bind to the promoter of NRT2.1; 2, to illustrate the genetic relationship between DELLA and GIP1; 3, to elucidate how DELLA-GIP1 interaction affect nitrate uptake in plant; eventually establish DELLA-GIP1 molecular model for the regulation of plant N uptake. The ultimate results of our studies will not only enhance the understanding of the molecular mechanism underlying the regulation of plant N uptake for us, but also provide a scientific and valuable theoretical basis for improving nitrogen uptake efficiency and grain yield of the dwarf crops in “ The first Green Revolution”, and resolving the ecological problem brought by the excessive application of nitrogen fertilizer.