水稻OsMKK1-OsMPK2级联调控抗病反应的方式与机制

越来越多的证据表明有丝分裂原活化蛋白激酶（MAPK）在植物抗病防卫反应中起着重要调控作用。但目前对植物MAPK调控抗病免疫反应机制的了解非常有限，且研究结果主要来自拟南芥和烟草，对禾本科作物MAPK功能的了解则更加匮乏。在前期的工作中，我们发现OsMKK1与OsMPK2蛋白相互作用，水稻mkk1和mpk2突变体具有相似的形态并都表现出对白叶枯病菌抗病性的减弱。这些结果暗示OsMKK1与OsMPK2极可能在同一抗病信号转导途径上起作用。本课题将深入研究水稻OsMKK1-OsMPK2级联调控抗病免疫的具体方式以及OsMKK1-OsMPK2级联的底物蛋白及其作用机理。该工作的开展将加深我们对单子叶植物MAPK级联调控抗病免疫机理的了解，并可能发现禾本科植物特异的MAPK调控抗病反应的组分和机制。研究结果将深入阐释水稻-病原微生物互作调控机制，同时为水稻抗病性的改良提供新的策略或靶标。

There is growing body of evidences suggesting that mitogen-activated protein kinase (MAPK) signaling plays critical roles in plant defense responses. However, molecular mechanism underlying the regulation of plant innate immunity by MAPKs is still not well understood. Furthermore, knowledge of the function of plant MAPKs comes mainly from studies on Arabidopsis and tobacco. Thus, current understanding of the MAPKs function in monocots is still preliminary. Recently we found that rice MAP kinase kinase OsMKK1 interacts with MAP kinase OsMPK2, and the rice mkk1 and mpk2 mutants showed similar morphological phenotypes and compromised resistance to bacterial blight, suggesting that the two kinases function in the same signaling cascade. The proposed study will focus on the following questions: 1) How does OsMKK1-OsMPK2 cascade regulate rice innate immunity; 2) What are the downstream targets of the OsMKK1-MPK2 cascade and their function in rice defense responses. The proposed research will lead to new insights into the regulation of defense response by MAP kinase cascade in monocots and possibly new monocot-specific components and mechanisms of MAPK signaling. The ultimate goal of these studies is to further reveal regulatory mechanisms of rice-pathogen interactions, meanwhile to provide new strategies and targets for plant disease resistance improvement.