Arabidopsis AtPLC2 Is a Primary Phosphoinositide-Specific Phospholipase C in Phosphoinositide Metabolism and the Endoplasmic Reticulum Stress Response

PLoS Genet. 2015 Sep 24;11(9):e1005511. doi: 10.1371/journal.pgen.1005511. eCollection 2015 Sep.

Abstract

Phosphoinositides represent important lipid signals in the plant development and stress response. However, multiple isoforms of the phosphoinositide biosynthetic genes hamper our understanding of the pivotal enzymes in each step of the pathway as well as their roles in plant growth and development. Here, we report that phosphoinositide-specific phospholipase C2 (AtPLC2) is the primary phospholipase in phosphoinositide metabolism and is involved in seedling growth and the endoplasmic reticulum (ER) stress responses in Arabidopsis thaliana. Lipidomic profiling of multiple plc mutants showed that the plc2-1 mutant increased levels of its substrates phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate, suggesting that the major phosphoinositide metabolic pathway is impaired. AtPLC2 displayed a distinct tissue expression pattern and localized at the plasma membrane in different cell types, where phosphoinositide signaling occurs. The seedlings of plc2-1 mutant showed growth defect that was complemented by heterologous expression of AtPLC2, suggesting that phosphoinositide-specific phospholipase C activity borne by AtPLC2 is required for seedling growth. Moreover, the plc2-1 mutant showed hypersensitive response to ER stress as evidenced by changes in relevant phenotypes and gene expression profiles. Our results revealed the primary enzyme in phosphoinositide metabolism, its involvement in seedling growth and an emerging link between phosphoinositide and the ER stress response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Endoplasmic Reticulum Stress*
  • Gene Expression Profiling
  • Genes, Plant
  • Mutation
  • Phosphatidylinositols / metabolism*
  • Phosphoinositide Phospholipase C / genetics
  • Phosphoinositide Phospholipase C / metabolism*
  • Plant Roots / metabolism
  • Subcellular Fractions / enzymology

Substances

  • Phosphatidylinositols
  • Phosphoinositide Phospholipase C

Grant support

This study was financially supported by grants from Institute of Plant and Microbial Biology, Academia Sinica to KK and YN, Ministry of Science and Technology, Taiwan (MOST 102-2311-B-001-015) to KK, Japan Society for the Promotion of Science Grants-in-Aid for Scientific Research (grant number 25440123) to KK, and grants from the National University of Singapore via the Life Sciences Institute (LSI) and a BMRC-SERC joint grant (BMRC-SERC 112 148 0006) from the Agency for Science, Technology and Research (A*Star) to MRW. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.