title: Missing links in understanding redox signaling via thiol/disulfide modulation: how is glutathione oxidized in plants?
abstract: Glutathione is a small redox-active molecule existing in two main stable forms: the thiol (GSH) and the disulphide (GSSG). In plants growing in optimal conditions, the GSH:GSSG ratio is high in most cell compartments. Challenging environmental conditions are known to alter this ratio, notably by inducing the accumulation of GSSG, an effect that may be influential in the perception or transduction of stress signals. Despite the potential importance of glutathione status in redox signaling, the reactions responsible for the oxidation of GSH to GSSG have not been clearly identified. Most attention has focused on the ascorbate-glutathione pathway, but several other candidate pathways may couple the availability of oxidants such as H2O2 to changes in glutathione and thus impact on signaling pathways through regulation of protein thiol-disulfide status. We provide an overview of the main candidate pathways and discuss the available biochemical, transcriptomic, and genetic evidence relating to each. Our analysis emphasizes how much is still to be elucidated on this question, which is likely important for a full understanding of how stress-related redox regulation might impinge on phytohormone-related and other signaling pathways in plants.
authors: Institut de Biologie des Plantes, Université Paris-Sud Orsay, France ; Institut National de Recherche Agronomique, UMR Environnement et Grandes Cultures Thiverval-Grignon, France.
authors: Marie-Sylviane
authors: MS
authors: Rahantaniaina
authors: Andrée
authors: A
authors: Tuzet
authors: Amna
authors: A
authors: Mhamdi
authors: Graham
authors: G
authors: Noctor
keywords: dehydroascorbate; glutaredoxin; glutathione S-transferase; hydrogen peroxide; oxidative stress