Glutathione as a key player in plant abiotic stress responses and tolerance

Abstract

Adverse environmental conditions, such as drought, salinity, high temperature, and toxic metal accumulation, affect plant growth and fitness. Plants have evolved a number of interconnected molecular pathways to defend themselves against different abiotic stresses. In these metabolic networks, redox signaling plays a pivotal role in determining plant tolerance to stress and survival. Glutathione/ glutathione disulfide is one of the most versatile redox couples in metabolism. It directly or indirectly buffers the cellular redox state, by acting as enzyme cofactor, controlling the oxido-reduction of other thiols and participating in post-translational protein modifications under both physiological and stress conditions. Glutathione also plays a key role as a conjugating agent in detoxification against xenobiotics or metabolites which need to be sequestered within the vacuole. Glutathione also acts as a signal controlling gene expression and cell cycle progression. These features highlight the importance of glutathione in regulating plant growth and development as well as in conferring tolerance to plants subjected to stress. This chapter describes the involvement of this multifaceted molecule in plant abiotic stress responses.