Review of oxidative stress and antioxidative defense mechanisms in Gossypium hirsutum L. in response to extreme abiotic conditions

Oxidative stress occurs when crop plants are exposed to extreme abiotic conditions that lead to the excessive production and accumulation of reactive oxygen species (ROS). Those extreme abiotic conditions or stresses include drought, high temperature, heavy metals, salinity, and ultraviolet radiation, and they cause yield and quality losses in crops. ROS are highly reactive species found in nature that can attack plant organelles, metabolites, and molecules by interrupting various metabolic pathways until cell death occurs. Plants have evolved defense mechanisms for the production of antioxidants to detoxify the ROS and to protect the plant against oxidative damage. Modern researches in crop plants revealed that low levels of ROS act as a signal which induces tolerance to environmental extremes by altering the expression of defensive genes. In this review, we summarized the processes involved in ROS production in response to several types of abiotic stress in cotton plants. Furthermore, we discussed the achievements in the understanding and improving oxidative stress tolerance in cotton in recent years. Researches related to plant oxidative stresses have shown excellent potential for the development of stress-tolerant crops.