Signal Transduction Across Plant Plasma Membranes

植物细胞在被称为激发子的病原体来源或植物细胞壁来源的分子刺激下合成多种防御化合物。虽然人们对这些激发子的性质和响应激发而产生的防御分子的类型了解很多，但实际上对将细胞外激发子信号转导到细胞核中的事件序列一无所知。本研究的目的是确定在激发过程中发生在质膜上的信号转导和放大过程。以动物细胞中的信号转导通路为模型，本项目的目标是评估以下信号机制在引发植物抗毒素形成过程中的可能参与：1)钙转运，2)质子转运，3)膜电位的变化，4)跨质膜脱氢酶活性的变化，5)磷脂酰肌醇转化的变化。重点将放在机制1、2和3上。对植物细胞信号转导过程的详细了解具有重要的内在意义，并可能最终有助于合理设计操纵植物各种防御和生长反应的策略。

Plant cells synthesize a variety of defense compounds upon stimulation with pathogen-derived or plant cell wall-derived molecules termed elicitors. While much is known concerning the nature of these elicitors and the types of defense molecules produced in response to elicitation, virtually nothing is known about the sequence of events involved in transducing the extracellular elicitor signal into the cell's nucleus. The objective of this research is to identify those signal transduction and amplification processes which occur at the plasma membrane during elicitation. Using signal transduction pathways in animal cells as models, the goals of this project are to evaluate the possible participation of the following signaling mechanisms during elicitation of phytoalexin formation: 1) calcium transport, 2) proton transport, 3) changes in membrane potential, 4) changes in trans-plasma membrane dehydrogenase activity, and 5) changes in phosphatidylinositol turnover. Emphasis will be placed on mechanisms 1, 2, and 3. A detailed understanding of signal transduction processes in plant cells is of great intrinsic interest and may eventually contribute to the rational design of strategies for manipulating the various defense and growth responses in plants.