Targeting redox regulatory mechanisms for salinity stress tolerance in crops

Salinity stress is one of the major abiotic stresses that result in significant losses in agricultural crop production across the globe. Salinity stress results in osmotic stress, ionic stress, and oxidative stress; among these, oxidative stress is considered to be the most detrimental. Oxidative stress induces the production of different reactive oxygen species (ROS) at both intracellular and extracellular locations. Plants possess redox regulatory mechanisms by employing different enzymatic and nonenzymatic antioxidants to scavenge ROS. Different antioxidants have different tissue- and organelle-specific ROS-scavenging effects. However, the causal link between the amount of antioxidants and plant salinity stress tolerance is not as straightforward as one may assume, with controversial reports available in the literature. This chapter addresses those controversies and argues that there is a need for better understanding and development of tools for targeted regulation of plant redox systems in specific cellular compartments and tissues.