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Journal of Botany
Volume 2012 (2012), Article ID 217037, 26 pages
Review Article

Reactive Oxygen Species, Oxidative Damage, and Antioxidative Defense Mechanism in Plants under Stressful Conditions

1Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
2Crop Development Centre, Department of Plant Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon SK, SK, Canada S7N 5A8
3School of Plant Sciences, The University of Arizona, Forbes Building, Room 303, P.O. Box 210036, Tucson, AZ 85721-0036, USA

Received 6 August 2011; Revised 12 February 2012; Accepted 12 February 2012

Academic Editor: Andrea Polle

Copyright © 2012 Pallavi Sharma et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Reactive oxygen species (ROS) are produced as a normal product of plant cellular metabolism. Various environmental stresses lead to excessive production of ROS causing progressive oxidative damage and ultimately cell death. Despite their destructive activity, they are well-described second messengers in a variety of cellular processes, including conferment of tolerance to various environmental stresses. Whether ROS would serve as signaling molecules or could cause oxidative damage to the tissues depends on the delicate equilibrium between ROS production, and their scavenging. Efficient scavenging of ROS produced during various environmental stresses requires the action of several nonenzymatic as well as enzymatic antioxidants present in the tissues. In this paper, we describe the generation, sites of production and role of ROS as messenger molecules as well as inducers of oxidative damage. Further, the antioxidative defense mechanisms operating in the cells for scavenging of ROS overproduced under various stressful conditions of the environment have been discussed in detail.