Glutathione is not involved in light-, Dark-, Ca- and H2O2- induced stomatal movement in Arabidopsis

Glutathione (GSH), is a thiol-containing tripeptide, maintains redox homeostasis in plants under normal and stressful conditions. In this study, we investigated whether GSH involved in light-, dark-, Ca- and H2O2-induced stomatal movement in Arabidopsis. Application of GSH and a GSH decreasing chemical (CDNB; 1-chloro-2,4-dinitrobenzene) did not affect stomatal aperture in guard cells of Arabidopsis. Dark induced stomatal closure and light induced stomatal opening but pre-treatment of GSH and CDNB did not alter dark- and light-induced stomatal aperture. Treatment of guard cells with Ca and H2O2 did not affect GSH contents in guard cells but induced stomatal closure in both wild type and chorinal-1 (ch1-1) mutant plants. In addition, pre-treatment of GSH and CDNB did not affect Ca and H2O2-induced stomatal closure in both plants. Taken together these results suggest that GSH might not directly affect light-, dark-, Ca- and H2O2-induced stomatal movement in guard cells of Arabidopsis.