The calcium-permeable channel OSCA1.3 regulates plant stomatal immunity

Nature. 2020 Sep;585(7826):569-573. doi: 10.1038/s41586-020-2702-1. Epub 2020 Aug 26.

Abstract

Perception of biotic and abiotic stresses often leads to stomatal closure in plants1,2. Rapid influx of calcium ions (Ca2+) across the plasma membrane has an important role in this response, but the identity of the Ca2+ channels involved has remained elusive3,4. Here we report that the Arabidopsis thaliana Ca2+-permeable channel OSCA1.3 controls stomatal closure during immune signalling. OSCA1.3 is rapidly phosphorylated upon perception of pathogen-associated molecular patterns (PAMPs). Biochemical and quantitative phosphoproteomics analyses reveal that the immune receptor-associated cytosolic kinase BIK1 interacts with and phosphorylates the N-terminal cytosolic loop of OSCA1.3 within minutes of treatment with the peptidic PAMP flg22, which is derived from bacterial flagellin. Genetic and electrophysiological data reveal that OSCA1.3 is permeable to Ca2+, and that BIK1-mediated phosphorylation on its N terminus increases this channel activity. Notably, OSCA1.3 and its phosphorylation by BIK1 are critical for stomatal closure during immune signalling, and OSCA1.3 does not regulate stomatal closure upon perception of abscisic acid-a plant hormone associated with abiotic stresses. This study thus identifies a plant Ca2+ channel and its activation mechanisms underlying stomatal closure during immune signalling, and suggests specificity in Ca2+ influx mechanisms in response to different stresses.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Abscisic Acid / metabolism
  • Arabidopsis / immunology*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Calcium / metabolism*
  • Calcium Channels / metabolism*
  • Pathogen-Associated Molecular Pattern Molecules / immunology
  • Pathogen-Associated Molecular Pattern Molecules / metabolism
  • Phosphorylation
  • Plant Immunity*
  • Plant Stomata / immunology*
  • Plant Stomata / metabolism*
  • Protein Binding
  • Protein-Serine-Threonine Kinases / metabolism
  • Signal Transduction

Substances

  • Arabidopsis Proteins
  • Calcium Channels
  • OSCA1 protein, Arabidopsis
  • Pathogen-Associated Molecular Pattern Molecules
  • Abscisic Acid
  • BIK1 protein, Arabidopsis
  • Protein-Serine-Threonine Kinases
  • Calcium