A Multifactorial Regulation of Glutathione Metabolism behind Salt Tolerance in Rice

Abstract

Knowledge of the stress-induced metabolic alterations in tolerant and sensitive plants is pivotal for identifying interesting traits that improve plant resilience toward unfavorable environ-mental conditions. This represents a hot topic area of plant science, particularly for crops, due to its implication in food security. Two rice varieties showing dissimilar resistance to salt, Baldo and Vi-alone Nano, have been studied to investigate the mechanisms underpinning tolerance toward sa-linity, and these studies have focused on the root system. A detailed analysis of the salt stress-de-pendent modulation of the redox network is here presented. The different phenotype observed after salt exposure in the two rice varieties is coherent with a differential regulation of cell-cycle progression and cell-death patterns observed at root level. Baldo, the tolerant variety, already showed a highly responsive antioxidative capacity in control conditions. Consistently, stressed Baldo plants showed a different pattern of H2O2 accumulation compared to Vialone Nano. Moreover, glutathione metabolism was finely modulated at transcriptional, post-transcriptional, and post-translational levels in Baldo. These results contribute to highlight the role of ROS and antioxidative pathways as a part of a complex redox network activated in rice toward salt stress.