促分裂原活化蛋白激酶级联途径（MPKKK-MPKK-MPK）在介导植株非生物逆境信号转导中发挥重要作用。本课题以前期鉴定的在介导植株抵御干旱、高盐、低氮和低磷逆境中发挥重要功能的小麦MAP激酶TaMPK3和TaMPK4基因为基础，鉴定与供试基因编码蛋白互作的上游组分，构建TaMPK3和TaMPK4级联通路，解析通路中各组分磷酸化机制；通过对TaMPK3和TaMPK4及上游组分基因与报告基因GFP融合蛋白荧光检测结合双分子荧光互补（BiFC）分析，揭示TaMPK3和TaMPK4级联通路介导胁迫信号转导的亚细胞部位；利用基因芯片阐明TaMPK3和TaMPK4调控逆境下的转录谱特征，对网络中关键调节基因编码蛋白与TaMPK3和TaMPK4的互作进行验证，进一步对上述基因介导植株抵御逆境的功能进行鉴定。通过研究，解析TaMPK3和TaMPK4构建的MPK特定级联通路及其介导植株抵御逆境分子机制。

The mitogen-activated protein kinase (MAPK) cascades are consisted of components of MAPKKK, MAPKK, and MAPK and involved in mediating the transduction of distinct signaling cues after sequential phosphorylation reactions. They play important roles in regulating plant growth, development and plant tolerance to diverse environmental stresses. In this project, two wheat MAPK member referred to TaMPK3 and TaMPK4 that we previously identified to act as essential regulators in plant tolerance to a set of stresses, such as drought, high salinity, nitrogen and phosphorus deprivations, will be subjected to further investigation. The main research contents are as follows: we will identify the upstream components interacted with TaMPK3 and TaMPK4 on which to establish the cascade modules comprised by these wheat MAPK members. The phosphorylation mechanism of these MAPK cascade members will be further dissected. Based on generating the fusion proteins of the MAPK cascade gene with GFP, a green fluorescence reporter gene together with further fluorescence signal detection for these fusions and bimolecular fluorescence complementation (BiFC) analysis, we will define the acting positions of the MAPK cascade members. Using gene chip approach, we will investigate the plant transcroptome characterization under stresses of drought, high salinity, nitrogen and phosphorus deprivations regulated by TaMPK3 and TaMPK4, on which to establish the gene networks specifically controlled by these MAPK genes. Furthermore, we will experimentally validate the putative interactions of an array of proteins encoded by key regulatory genes in gene networks with TaMPK3 and TaMPK4. The functions of these regulatory genes in mediating plant tolerance to diverse stresses will be further determined. Together, we will dissect the distinct MAPK cascade module covering TaMPK3 and TaMPK4 and elucidate the molecular mechanisms of these MAPK cascade pathways in regulating plant tolerance to drought, high salinity, nitrogen and phosphorus deprivations.