Inositol polyphosphate phosphatidylinositol 5-Phosphatase9 (At5PTase9) controls plant salt tolerance by regulating endocytosis

Yael Golani, Yuval Kaye, Omri Gilhar, Mustafa Ercetin, Glenda Gillaspy, Alex Levine*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

43 Scopus citations

Abstract

Phosphatidylinositol 5-phosphatases (5PTases) that hydrolyze the 5' position of the inositol ring are key components of membrane trafficking system. Recently, we reported that mutation in At5PTase7 gene reduced production 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' phosphate 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 production 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 At5ptase9 mutants. In summary, our results show a key non-redundant role of At5PTase7 and 9 isozymes, and underscore the localization of membrane-bound PtdIns in regulating plant salt tolerance by coordinating the endocytosis, ROS production, Ca2+ influx, and induction of stress-responsive genes.

Original languageAmerican English
Pages (from-to)1781-1794
Number of pages14
JournalMolecular Plant
Volume6
Issue number6
DOIs
StatePublished - Nov 2013

Bibliographical note

Funding Information:
The research was supported by grant from the Israel Science Foundation (ISF) . No conflict of interest declared.

Keywords

  • Abiotic/environmental stress
  • Gene expression
  • Oxidative and photo-oxidative stress
  • Protein traffic and secretion
  • Salinity

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