INVOLVEMENT OF GLUTATHIONE IN ABSCISIC ACID SIGNALING AND METHYL JASMONATE SIGNALING IN GUARD CELLS

Stomata are formed by pairs of guard cells, which control the gaseous exchange and transpirational water loss in plants. The opening and closure of stomata are regulated by the integration of numerous environmental signals and endogenous hormonal stimuli. In response to drought stress, plants synthesize a hormone, abscisic acid (ABA), which triggers the signal transduction in the guard cells and induces stomatal closure that prevents water loss by transpiration. Methyl jasmonate (MeJA) is a phytohormone that regulates various physiological processes and mediates plant defense responses. Similar to ABA, MeJA plays a role in the induction of stomatal closure. Glutathione (GSH; γ-glutamylcysteinyl glycine) is an abundant, ubiquitous, and non-enzymatic antioxidant that has significant functions in the growth, development, defense systems, signaling, and gene expression in plants. In recent years, many studies have shown that GSH is involved in the ABA- and MeJA-induced stomatal closure. In this study, we outline the involvement of GSH in the stomatal closure and discuss how GSH regulates ABA signaling and MeJA signaling in the guard cells.