GmSAL1 hydrolyzes inositol-1,4,5-trisphosphate and regulates stomatal closure in detached leaves and ion compartmentalization in plant cells

PLoS One. 2013 Oct 22;8(10):e78181. doi: 10.1371/journal.pone.0078181. eCollection 2013.

Abstract

Inositol polyphosphatases are important regulators since they control the catabolism of phosphoinositol derivatives, which are often signaling molecules for cellular processes. Here we report on the characterization of one of their members in soybean, GmSAL1. In contrast to the substrate specificity of its Arabidopsis homologues (AtSAL1 and AtSAL2), GmSAL1 only hydrolyzes inositol-1,4,5-trisphosphate (IP3) but not inositol-1,3,4-trisphosphate or inositol-1,4-bisphosphate.The ectopic expression of GmSAL1 in transgenic Arabidopsis thaliana led to a reduction in IP3 signals, which was inferred from the reduction in the cytoplasmic signals of the in vivo biomarker pleckstrin homology domain-green florescent protein fusion protein and the suppression of abscisic acid-induced stomatal closure. At the cellular level, the ectopic expression of GmSAL1 in transgenic BY-2 cells enhanced vacuolar Na(+) compartmentalization and therefore could partially alleviate salinity stress.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / genetics
  • Abscisic Acid / metabolism
  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Inositol Phosphates / genetics
  • Inositol Phosphates / metabolism*
  • Nucleotidases / genetics
  • Nucleotidases / metabolism*
  • Phosphoric Monoester Hydrolases
  • Plant Stomata / genetics
  • Plant Stomata / metabolism*
  • Plants, Genetically Modified / enzymology
  • Plants, Genetically Modified / genetics
  • Salinity
  • Sequence Homology
  • Signal Transduction / physiology*
  • Sodium / metabolism
  • Soybeans / enzymology*
  • Soybeans / genetics
  • Stress, Physiological / physiology

Substances

  • Arabidopsis Proteins
  • Inositol Phosphates
  • inositol-1,2,4,5-tetrakisphosphate
  • Abscisic Acid
  • Sodium
  • Nucleotidases
  • Phosphoric Monoester Hydrolases
  • inositol-1,4-bisphosphate 1-phosphatase

Grant support

Sources of funding: Hong Kong Research Grants Council General Research Fund (Grant no. 468409), Lo Kwee-Seong Biomedical Research Fund, and Lee Hysan Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.