ABSTRACT
Salinity negatively influences plant growth and development, leading to reduced crop yield and quality, as well as affecting agricultural sustainability. During various processes associated with salt stress, reactive oxygen species (ROS) are generated in different parts of stressed plant cells, including chloroplasts, peroxisomes, mitochondria and apoplast, through which the equilibrium in antioxidant defense systems is disturbed. In this context, the equilibrium between the detoxification and generation of ROS is maintained by both enzymatic and non-enzymatic antioxidant defense systems under salinity stress. Recent advances have clearly elucidated the role of enzymatic and non-enzymatic antioxidant defense systems in plants to detoxify ROS. Although there are many reports on the role of antioxidant defense in plants when exposed to salt stress, the relative importance of this process for the overall tolerance of the plant as well as the existing mechanisms by which the plant resists salinity are still controversial. This chapter provides an updated discussion on salt-induced oxidative stress at the subcellular level and its effect on the antioxidant machinery including both enzymatic and non-enzymatic defense systems.
