NAD激酶（NAD kinase, NADK）是生物体内唯一催化NAD(H)和ATP合成NADP(H)的酶，在植物代谢调控中具重要功能。我们前期研究表明，小麦中存在4种NADK，其中TaNADK4定位于过氧化物酶体，其表达受脱落酸（abscisic acid, ABA）和茉莉酸（jasmonic acid, JA）及干旱等的强烈诱导，且两个HOX（homeobox）家族转录因子TaHOX1和TaHD-ZipI-1可与其启动子结合，但TaNADK4过氧化物酶体定位并参与干旱等逆境应答的机制不清。本项目拟在此基础上，通过遗传转化、蛋白互作及转录调控分析等，深入解析TaNADK4过氧化物酶体定位的调控方式，揭示两个HOX转录因子调控其表达及与ABA和JA等激素的互作关系，最终结合转基因抗性分析，阐明TaNADK4参与小麦干旱应答的分子调控机制，为过氧化酶体抗逆功能及小麦耐旱机制的阐明提供新依据。

NAD kinase (NADK) is the sole enzyme that catalyzes NAD(H) and ATP to produce NADP(H) in almost all living organisms and therefore plays vital roles in many important metabolic pathways and stress responses of plants. In our previous studies, we found that there are 4 NADK isoforms in wheat cells and among them TaNADK4 is located in peroxisome. Further studies showed that the expression of TaNADK4 was significantly stimulated by plant hormones such as abscisic acid (ABA) and jasmonic acid (JA), and two homeobox (HOX) transcription factors, TaHOX1 and TaHD-Zipl-1, were found to bind to the promoter of TaNADK4 gene. However, the functions of TaNADK4 in peroxisome and the molecular mechanisms in drought stress tolerance are still under investigation. In the present project, the functions of TaNADK4 and its molecular mechanism in drought stress responses will be comprehensively investigated by employing a number of biological approaches including transgenic plant creation, protein interaction analysis and stress response network clarification. By this study, we will focus on (1) understand the mode of the localization of TaNADK4 to peroxisome and its biological role in the organelle; (2) clarify the molecular mechanisms of the two HOX transcription factors in the expression control of TaNADK4; (3) clarify the interactions between TaNADK4 and ABA and JA signaling; (4) demonstrate the functional mechanism of TaNADK4 in drought stress response. The results obtained here will provide new insights for the functions of peroxisome in plant stress tolerance and therefore benefits to the improvement of stress tolerance for wheat by biotechnological ways in the future.