• A.SRINIVASA RAO
• K V MADHUSUDHAN
• S SUBRAMANYAM

At the moment, climate change is thought to be the biggest environmental concern. Due of its significant impact on agriculture, it is currently receiving a lot of attention from farmers, researchers, and politicians. Global climate change, environmental unpredictability, and the environment's increasing complexity are all contributing factors to the situation's growing severity. Drought has a severe negative impact on crop plant growth and development, making it one of the most severe environmental pressures now affecting agriculture. During a number of processes linked to drought stress, plant cells generate oxygen radicals and their byproducts, known as reactive oxygen species (ROS). The four major active oxygen species includes superoxide anion (Radicals) (O2•−), singlet oxygen (1O2), hydrogen peroxide (H2O2) and hydroxyl radical (OH•). One of the most crucial consequences of abiotic stress is the disturbance of the equilibrium between the generation of ROS and antioxidant defense systems triggering the excessive accumulation of ROS and inducing oxidative stress in plants. ROS are highly reactive in the absence of any protective mechanism and can seriously disrupt normal metabolism through oxidative damage to membrane lipids, proteins, carbohydrates, pigments and nucleic acids, which ultimately results in the cell death. The major potential sources of ROS in plants are chloroplasts, mitochondria and peroxisomes. Enzymatic and nonenzymatic antioxidant defence systems maintain the equilibrium between the detoxification and generation of ROS under water deficit conditions. One of the most important effects of water stress is the disruption of the balance between the production of reactive oxygen species (ROS) and antioxidant defence systems, which leads to an excessive build-up of ROS and oxidative stress in plants. ROS are highly reactive in the absence of any protective mechanism and can seriously disrupt normal metabolism through oxidative damage to membrane lipids, proteins, carbohydrates, pigments and nucleic acids, which ultimately results in the cell death. Chloroplasts, mitochondria, and peroxisomes are the main possible sources of ROS in plants. Under conditions of water stress, the balance between ROS formation and detoxification is maintained by both enzymatic and nonenzymatic antioxidant defence systems. The literature is reviewed in terms of ROS production and its antioxidative defence mechanism during drought.

Drought stress, ROS, Antioxidant defense, Oxidative stress

"Oxidative Stress and Antioxidant Defense System in Plants under Drought Stress ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.11, Issue 12, page no.g42-g47, December-2024, Available :http://www.jetir.org/papers/JETIR2412607.pdf

"Oxidative Stress and Antioxidant Defense System in Plants under Drought Stress ", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.11, Issue 12, page no. ppg42-g47, December-2024, Available at : http://www.jetir.org/papers/JETIR2412607.pdf