STOMATAL OPENING IS INDUCED IN EPIDERMAL PEELS OF COMMELINA-COMMUNIS L BY GTP ANALOGS OR PERTUSSIS TOXIN

Abstract

Pretreatment with pertussis toxin or microinjection of guanosine-5'-(3-thiotriphosphate) (GTP-gamma-S) into guard cells in peeled epidermis of Commelina communis L. promoted stomatal opening under subsaturating white light. Guanosine-5'-(2-thiodiphosphate) (GDP-beta-S) and adenosine-5'-(3-thiotriphosphate) (ATP-gamma-S) did not change stomatal aperture under identical conditions. These results indicate that G proteins may be involved in the regulation of stomatal opening.