, Volume 206, Issue 2, pp 308–314

Putative involvement of cytosolic Ca2+ and GTP-binding proteins in cyclic-GMP-mediated induction of stomatal opening by auxin in Commelina communis L.

  • Alain Cousson
  • Alain Vavasseur

DOI: 10.1007/s004250050405

Cite this article as:
Cousson, A. & Vavasseur, A. Planta (1998) 206: 308. doi:10.1007/s004250050405


To investigate whether cyclic GMP (cGMP) would mediate, in an intracellular Ca2+ -dependent manner, coupling of auxin to stomatal opening, the stomatal opening responses to the auxin indolyl-3-butyric acid (IBA) and to the cGMP membrane-permeable derivative 8-bromoguanosine 3,5-cyclic monophosphate (8-Br-cGMP) were compared in epidermal strips of Commelina communis. In this comparison were studied possible effects of intracellular Ca2+ modulators, GTP-binding protein (G-protein) modulators and selective inhibitors of enzymatic reactions which use or generate cGMP. The stomatal response to IBA was almost similarly reversed by the Ca2+ buffer 1,2-bis(o-aminophenoxy)ethane-N,N,N,N-tetraacetic acid (BAPTA), the intracellular Ca2+-release inhibitors ruthenium red and procaine, the inactive cGMP analog Rp-8-bromoguanosine 3,5-cyclic monophosphorothioate (Rp-8-Br-cGMPS), the inhibitor of cGMP-producing guanylyl cyclase LY 83583, the G-protein inhibitor mas17 and the G-protein antagonist pGlu-Gln-D-Trp-Phe-D-Trp-D-Trp-Met-NH2. Comparison with stomatal opening in response to 8-Br-cGMP, which was almost completely suppressed by either BAPTA, ruthenium red, procaine or Rp-8-Br-cGMPS, strongly suggests that cGMP acts downstream of G-protein activation as a second messenger for IBA signal transduction and that the cGMP pathway likely depends on cytosolic Ca2+signaling.

Key words: Auxin Commelina Cyclic GMP G-protein modulator Intracellular Ca2+ modulator Stomatal opening 

Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Alain Cousson
    • 1
  • Alain Vavasseur
    • 1
  1. 1.CEA/Cadarache-DSV-DEVM, Laboratoire de Bioénergétique Cellulaire, UMR 163 CNRS-CEA, F-13108 Saint-Paul-lez-Durance, Cedex, FranceFR