Dynamics and environmental responses of PATROL1 in Arabidopsis subsidiary cells

Plant Cell Physiol. 2014 Apr;55(4):773-80. doi: 10.1093/pcp/pct151. Epub 2013 Oct 24.

Abstract

The Arabidopsis stomatal complex is composed of a pair of guard cells and surrounding anisocytic subsidiary cells. Subsidiary cells are thought to function as a supplier and receiver of bulk water and ions, and to assist turgor-driven stomatal movement, but the molecular mechanisms are largely unknown. In this work, we studied the dynamic behavior and environmental responses of PATROL1, which has been identified as a translocation factor of the plasma membrane proton pump ATPase (PM H(+)-ATPase) AHA1 in guard cells and subsidiary cells in Arabidopsis thaliana. Variable-angle epifluorescence microscopic observation revealed that green fluorescent protein (GFP)-PATROL1 localized on dot-like compartments that resided on plasma membranes for several seconds. The GFP-PATROL1-labeled dots were sensitive to phosphatidylinositol 4-kinase inhibitors but not to a phosphatidylinositol 3-kinase inhibitor. GFP-PATROL1 and red fluorescent protein (RFP)-AHA1 co-localized in hyperosmotic conditions, and a mutation of PATROL1 resulted in an increase in GFP-AHA1 internalization, suggesting a role in the translocation of PM H(+)-ATPase in subsidiary cells. Interestingly, subsidiary cells showed changes in localization of GFP-PATROL1 in response to environmental stimuli that were opposite to those in guard cells. Our observations suggested that PATROL1 may contribute to stomatal movement by translocations of PM H(+)-ATPase in subsidiary cells.

Keywords: ABA; PATROL1; Proton pump ATPase; Stomata; Subsidiary cells; Variable-angle epifluorescence microscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscisic Acid / pharmacology
  • Arabidopsis / cytology*
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / metabolism*
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Environment*
  • Green Fluorescent Proteins / metabolism
  • Minor Histocompatibility Antigens
  • Models, Biological
  • Mutation / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / antagonists & inhibitors
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism
  • Plant Stomata / cytology
  • Plant Stomata / drug effects
  • Plant Stomata / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Protein Transport / drug effects
  • Proton-Translocating ATPases / metabolism
  • Recombinant Fusion Proteins / metabolism

Substances

  • Arabidopsis Proteins
  • Minor Histocompatibility Antigens
  • PATROL1 protein, Arabidopsis
  • Protein Kinase Inhibitors
  • Recombinant Fusion Proteins
  • Green Fluorescent Proteins
  • Abscisic Acid
  • Phosphotransferases (Alcohol Group Acceptor)
  • phosphatidylinositol phosphate 4-kinase
  • Proton-Translocating ATPases
  • AHA1 protein, Arabidopsis