ABSTRACT
Oxidative stress is produced by increasing the number of reactive oxygen species (ROS) or free radicals, which results in early aging, increased permeability, ions leakage from the cell membranes, and reduced photosynthesis in plants. Exposure to environmental stresses may increase the production of ROS and the oxidative stress, and eventually accelerate the damage to membranes, proteins, and deoxyribonucleic acid, changes in growth and physiological structure of the cells, and destroying enzymes. The harmful effects of ROS on cellular macromolecules can be reduced by the activity of antioxidant compounds such as ascorbic acid, glutathione, and carotenoids. The ROS scavenging enzymes in plant cells include catalase, superoxide dismutase, monodehydroascorbate, ascorbate peroxidase, dehydro-ascorbate reductase, glutathione reductase and glutathione peroxidase. The result of the research indicated that the activity of a set of antioxidant enzymes could lead to detoxification of ROS. Therefore, for a better understanding the ROS detoxifier factors, a comprehensive study should be done on the antioxidant system.
