磷脂酸在植物中的第二信使功能

磷脂酸(phosphatidic acid, PA)是植物中重要的细胞内信号分子，被称为“脂质第二信使”，特别是几个PA的作用靶点已被克隆和鉴定.植物体内PA的产生可以通过磷脂酶C和D两条信号通路，前者与甘油二酯激酶协同作用.PA主要由各种生物和非生物胁迫诱导产生，磷脂酸的水平在各种胁迫处理后的几分钟内增强.增强的信号水平通过PA的磷酸化形成甘油二酯焦磷酸而被迅速减弱.本文就PA产生的磷脂酶信号通路,PA在各种胁迫诱导下的产生,PA的作用靶点和作用机理及在植物中的功能等几个方面进行综述.

Biological Function of Phosphatidic Acid as a Second Messenger in Plants

Phosphatidic acid (PA) is an important intracellular signal molecule and is called the lipid second messenger because several targets of PA have especially been cloned and identified. Production of PA in vivo in plants is through the pathways of two signals of phospholipases C and D, and the former induces effect in cooperation with diacylglycerol kinase. PA is produced mainly via various biotic and abiotic stress conditions, and level of PA increases within minutes after a wide variety of stress treatments including pathogen elicitation, drought, salinity, wounding, cold and freezing, ethylene, abscisic acid and oxidative stress. Enhanced signal levels is rapidly attenuated through the formation of diacylglycerol pyrophosphate via phosphorylating PA. This lipid regulates a wide range of important cellular processes in plants, including regulation of ROS genetation, MAPK activity, K⁺ channels and actin organization. Moreover, PA is likely to be involved in numerous physiological processes in plants, including stomatal movement, leaf senescence, various stress responses, and hormone signaling. In this article, we review the production of PA, which includes its production from signaling pathways of the phospholipases and induction of various stress conditions, targets, mechanisms and functions in plants.