Inositol Polyphosphate Phosphatidylinositol 5-Phosphatase9 （At5PTase9） Controls Plant Salt Tolerance by Regulating Endocytosis

作     者：Yael Golania Yuval Kaye Omri Gilhar Mustafa Ercetin Glenda Gillaspy Alex Levine 

作者机构：Department of Plant and Environmental Sciences The Hebrew University of Jerusalem Givat-Ram Campus Jerusalem 91904 Israel Department of Biochemistry and Fralin Biotechn01ogy Center Virginia T'ech Blacksburg VA 24061 USA 

出 版 物：《Molecular Plant》 (分子植物（英文版）)

年 卷 期：2013年第6卷第6期

页      面：1781-1794页

核心收录：

学科分类：0710[理学-生物学] 081702[工学-化学工艺] 08[工学] 0817[工学-化学工程与技术] 09[农学] 0903[农学-农业资源与环境] 0901[农学-作物学] 0902[农学-园艺学] 

基　　金：supported by grant from the Israel Science Foundation (ISF) 

主　　题：abiotic/environmental stress oxidative and photo-oxidative stress salinity protein traffic and secretion gene expression Arabidopsis. 

摘      要：Phosphatidylinositol 5-phosphatases （5PTases） components of membrane trafficking system. Recently, we that hydrolyze the 5＇ position of the inositol ring are key reported that mutation in AtSPTase7 gene reduced produc- tion of reactive oxygen species （ROS） and decreased expression of stress-responsive genes, resulting in increased salt sensitivity. Here, we describe an even more salt-sensitive 5ptase mutant, At5ptase9, which also hydrolyzes the 5＇ phos- phate groups specifically from membrane-bound phosphatidylinositides. Interestingly, the mutants were more tolerant to osmotic stress. We analyzed the main cellular processes that may be affected by the mutation, such as production of ROS, influx of calcium, and induction of salt-response genes. The At5ptase9 mutants showed reduced ROS produc- tion and Ca2~ influx, as well as decreased fluid-phase endocytosis. Inhibition of endocytosis by phenylarsine oxide or Tyrphostin A23 in wild-type plants blocked these responses. Induction of salt-responsive genes in wild-type plants was also suppressed by the endocytosis inhibitors. Thus, inhibition of endocytosis in wild-type plants mimicked the salt stress responses, observed in the AtSptase9 mutants. In summary, our results show a key non-redundant role of At5PTase7 and 9 isozymes, and underscore the localization of membrane-bound Ptdlns in regulating plant salt tolerance by coordinating the endocytosis, ROS production, Ca2＋ influx, and induction of stress-responsive genes.