Glutathione Metabolism in Plants Under Metal and Metalloid Stress and its Impact on the Cellular Redox Homoeostasis

Abstract

Efficient phytoremediation of soils polluted with toxic elements greatly depends on the ability of selected plants to withstand the damages induced by these contaminants. Among other metabolites, glutathione (GSH) plays a fundamental dual role in tolerance as an antioxidant required for the attenuation of reactive oxygen species (ROS), such as superoxide (\({{\text{O}}_{ 2}}^{ \cdot - }\)) and hydrogen peroxide (H2O2) and as a precursor of phytochelatins (PCs). Understanding the regulatory mechanisms involved in sulphur assimilation and biothiols’ metabolism under metal and metalloid stress will provide the tools to select and obtain more tolerant plants with improved performance, where the cellular redox status and stress-related phytohormones are key players. Metal uptake and distribution depend greatly on the biothiol metabolism, and advanced metallomic analytical techniques offer the tools to characterize in detail functional aspects of metal(loid)–biothiol interaction. Therefore, we present in this chapter an insight in the impact of GSH on the cellular redox balance under metal stress, and how biothiols affect the dynamics of these contaminants in plants with possible implications for future phytoremediation approaches.