Suppression of the stomatal opening by morphactins in isolated epidermal strips

Abstract

The effects of three morphactins, chlorflurenol, flurenol and EMD 7301 W, were examined on the stomatal aperture using isolated epidermal strips of Commelina benghalensis. Morphactins produced, a striking decrease in the stomatal opening in light but had no effect on stomatal closure in darkness. Various catalysts and inhibitors of photophosphorylation had no influence on the morphactin-induced stomatal closure. The stimulatory effects of ATP, pyruvate and KC1 on stomatal opening were suppressed by the morphactins. The cytokinin, benzyladenine stimulated the stomatal opening even in the presence of a morphactin. The influence of morphactins on the stomatal aperture closely resembled the effect of abscisic acid. © 1976 Oxford University Press.