Glutathione-associated regulation of plant growth and stress responses

A reduced form of glutathione (GSH) is considered to protect the cell from oxidative damage, based on its redox buffering action and abundance in the cell. However, in plants, the high redox potential molecule ascorbate exists at comparable or higher concentrations and is used for scavenging hydrogen peroxide as an electron donor. Recently, examples that cannot be explained simply by the antioxidant activity of GSH have been increasing in number. This article summarizes the recent findings on the glutathione-associated events in plants, in particular, growth and development including cell differentiation, cell death and senescence, pathogen resistance, and enzymatic regulation.