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重要作用。拟南芥MPK3和MPK6以及它们在其他物种中的功能等同物与植物抗病性有关。然而，其潜在机制尚不清楚。最近，人们发现MPK3和MPK6的激活诱导氰化物积累，这导致在超敏反应期间叶绿体中产生活性氧（ROS）和细胞死亡。在这个项目中，研究人员将使用生理，生物化学和分子遗传学方法的组合来了解植物防御反应过程中氰化物积累的调节，并生成具有升高或降低氰化物积累的植物。这些植物的表型分析将提供在体内增益和损失的功能证据，建立氰化物作为一个新的调节/信号分子在植物中。氰化物是乙烯生物合成的副产物。乙烯作为一种植物激素，其在植物生理和发育过程中的作用及其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，尽管其对细胞中的许多关键酶和过程具有明显的生物学效应，但大多被忽视。更广泛的影响。本项目采用组合教学法，为学生和博士后提供了良好的培养环境。学生（包括研究生和本科生）和博士后从代表性不足的群体将积极招募，通过参与机构计划，接触到这些科学家。氰化物是叶绿体和线粒体中各种活动的有效抑制剂，这两种细胞器被称为细胞“动力植物”。了解氰化物积累的调节及其在能量转换、ROS产生和HR细胞死亡中的功能可能会导致在胁迫条件下产生产量提高的作物。这对于农业生产足够的粮食/饲料和可收获的能源以满足不断增长的需求至关重要。

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.