水资源短缺是制约农业生产的主要问题，生物节水在农业节水抗旱中具有重要作用。转录因子PIFs（光敏色素作用因子）在植物生长发育和信号调控中发挥枢纽作用。申请人前期研究发现玉米PIFs基因能够显著提高转基因水稻的节水抗旱性，且转基因水稻具有较好的农艺性状。但目前为止，还没有PIFs基因参与节水抗旱的报道。在此基础上，申请人筛选获得水稻PIFs家族基因OsPIL15（与玉米PIFs同源性最高），利用其过表达和敲除植株，拟开展以下工作：①过表达和敲除植株抗旱表型、生理和农艺性状分析，推断PIFs的节水抗旱功能；②酵母双杂交文库筛选、染色质免疫共沉淀-测序（ChIP-seq）和转录组测序（RNA-seq），获得PIFs节水抗旱蛋白复合体组成蛋白和下游调控基因。结合申请人已获取的玉米和拟南芥PIFs实验数据，解析水稻PIFs转录因子的节水抗旱调控机理，为作物抗旱分子遗传改良提供新的基因元件和策略。

The shortage of water resources is the main fact that restricts the agricultural production. Biological water saving plays an important role in agricultural water saving and drought resistance. Phytochrome-interacting factors (PIFs), as cellular signaling hubs, play a pivotal role in plant growth and development. We found from the previous study that maize PIFs transcription factors could significantly improve water-saving and drought-resistant ability of transgenic rice. Moreover, maize PIFs transcription factors were able to increase grain yield in transgenic rice. However, the function of PIFs involved in water-saving and drought-resistant has not been reported. On the basis of selected gene OsPIL15 from rice, which shares the highest homology with PIFs gene in maize, we construct the over-expression and knockout transgenic materials. This project aims to carry out researches as follows: ①The over-expression and knockout transgenic materials analyzing the function of water-saving and drought-resistant of OsPIL15 based on the phenotypic and physiological changes of transgenic plants. ②Screening the interacting protein and the downstream regulatory gene of OsPIL15 by the yeast two hybrid, ChIP-seq and RNA-seq analysis. Combined with the experimental data of PIFs gene obtained from maize and Arabidopsis thaliana, this project aims to explore the novel water-saving and drought-resistant regulatory mechanisms of the transcription factor PIFs, thereby providing new gene and idea for the genetic improvement of drought-resistant crops.