 Abiotic stress conditions greatly affect plant growth and development, ultimately impacting crop yield and agricultural sustainability. Plant cells produce reactive oxygen species, ROS, during various processes associated with abiotic stress, which can induce oxidative stress if not properly detoxified by enzymatic and non-enzymatic antioxidant defense systems. Recent research has shown the harmful effects of ROS on plant growth and development, as well as the molecular crosstalk between ROS and other important signal molecules such as reactive nitrogen, sulfur, and carbonyl species. State-of-the-art molecular approaches have also been discussed for improving plant antioxidant defense during acclamation to abiotic stresses. This article was authored by Mirza Hassanizaman, M. H. Amboranadan-Buyan, Faisal Zulfikar, and others.