Glutathione homeostasis in plants: implications for environmental sensing and plant development

Abstract

Glutathione (GSH; γ-glutamylcysteinyl glycine) is an abundant and ubiquitous thiol with proposed roles in the storage and transport of reduced sulphur, the synthesis of proteins and nucleic acids and as a modulator of enzyme activity. The level of glutathione has also been shown to correlate with the adaptation of plants to extremes of temperature, in the tolerance of plants to xenobiotics and to biotic and abiotic environmental stresses. In addition, the size of the reduced glutathione pool shows marked alterations in response to a number of environmental conditions. Taken together, these findings have prompted intense efforts to characterize in detail the mechanisms underlying glutathione homeostasis in plants and to elucidate the role of these responses in the strategies plants have evolved to adapt to environmental stresses. The aim of this review is to assess recent biochemical, molecular, genetic, and physiological advances which are increasing our understanding of the mechanisms by which plant glutathione homeostasis is controlled and the role of glutathione in the integration of cellular processes with plant growth and development under stress.