Activation of Plant Stress-Responsive MAP Kinases Induces Cyanide - its Role in Reactive Oxygen Species Generation and Hypersensitive Cell Death

丝裂原活化蛋白激酶(MAPK，或MPK)级联是保守的信号模块，在所有真核生物中发挥着至关重要的作用。拟南芥MPK3和MPK6以及它们在其他物种中的功能等价物与植物抗病有关。然而，潜在的机制尚不清楚。最近发现，MPK3和MPK6的激活诱导了氰化物的积累，导致叶绿体中活性氧物种(ROS)的产生，导致细胞在过敏反应中死亡。在这个项目中，研究人员将使用生理、生化和分子遗传学方法相结合的方法来了解植物防御反应中氰化物积累的调节，并培育氰化物积累增加或减少的植物。对这些植物的表型分析将提供体内功能获得和丧失的证据，以确定氰化物是植物中一种新的调节/信号分子。氰化物是乙烯生物合成的副产物。作为一种植物激素，乙烯一直是研究的热点，它在植物生理发育过程中的作用以及乙烯的作用机制已被广泛研究。然而，氰化物作为植物中的一种调节分子，尽管它对细胞中的一些关键酶和过程具有明显的生物学效应，但却大多被忽视。更广泛的影响。在这个项目中使用组合方法将为学生和博士后提供一个良好的培训环境。来自代表性不足群体的学生(包括研究生和本科生)和博士后将通过参加接触这类科学家的机构项目积极招募。氰化物是一种有效的抑制叶绿体和线粒体中各种活动的物质，这两种细胞器被称为细胞“发电厂”。了解氰化物积累的规律及其在能量转换、ROS产生和HR细胞死亡中的作用，可能会导致在胁迫条件下产生高产作物。这对农业生产足够的食物/饲料和可收获的能源以满足日益增长的需求非常重要。

Mitogen-activated protein kinase (MAPK, or MPK) cascades are conserved signaling modules that play vital roles in all eukaryotic organisms. Arabidopsis MPK3 and MPK6, as well as their functional equivalents in other species, are implicated in plant disease resistance. However, the underlying mechanism is unclear. Recently, it was discovered that activation of MPK3 and MPK6 induces cyanide accumulation, which leads to the generation of reactive oxygen species (ROS) in chloroplasts and cell death during the hypersensitive response. In this project, the investigators will use a combination of physiological, biochemical, and molecular genetic approaches to understand the regulation of cyanide accumulation during plant defense response and to generate plants with either elevated or reduced cyanide accumulation. Phenotypic analyses of these plants will provide in vivo gain- and loss-of-functional evidence to establish cyanide as a new regulatory/signaling molecule in plants. Cyanide is a co-product of ethylene biosynthesis. As a plant hormone, ethylene has been the focus of much study, its role in plant physiological and developmental processes, as well as the mechanisms of ethylene action have been investigated extensively. However, cyanide as a regulatory molecule in plants has been mostly ignored, despite its obvious biological effects on a number of critical enzymes and processes in cells. Broader impacts. The use of a combinatory approach in this project will provide an excellent training environment for students and post-docs. Students (both graduate and undergraduate) and post-docs from under-represented groups will be actively recruited though participation in institutional programs which reach out to such scientists. Cyanide is a potent inhibitor of various activities in chloroplasts and mitochondria, two organelles known as cellular 'power plants'. Understanding the regulation of cyanide accumulation and its functions in energy conversion, ROS generation, and HR cell death may lead to the generation of crops with enhanced yield under stress conditions. This is important for agriculture to produce enough food/feed and harvestable energy to meet an increasing demand.