Signal Transduction Across Plant Plasma Membranes

植物细胞在病原体来源的分子或植物细胞壁来源的分子的刺激下合成各种防御化合物，称为激发子。虽然关于这些激发子的性质和在诱导反应中产生的防御分子的类型已经知道很多，但对于将细胞外激发子信号传递到细胞核中所涉及的事件序列几乎一无所知。这项研究的目的是确定在诱导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下列信号机制在植物保卫素形成过程中的可能参与：1)钙转运，2)质子转运，3)膜电位变化，4)跨质膜脱氢酶活性变化，5)磷脂酰肌醇周转率变化。重点将放在机制1、2和3上。详细了解植物细胞中的信号转导过程具有重要的内在意义，最终可能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.