Roles of enzymatic and nonenzymatic antioxidants in plants during abiotic stress

Abstract

Reactive oxygen species (ROS) are produced in plants as byproducts during many metabolic reactions, such as photosynthesis and respiration. Oxidative stress occurs when there is a serious imbalance between the production of ROS and antioxidant defense. Generation of ROS causes rapid cell damage by triggering a chain reaction. Cells have evolved an elaborate system of enzymatic and nonenzymatic antioxidants which help to scavenge these indigenously generated ROS. Various enzymes involved in ROS-scavenging have been manipulated, over expressed or downregulated to add to the present knowledge and understanding the role of the antioxidant systems. The present article reviews the manipulation of enzymatic and nonenzymatic antioxidants in plants to enhance the environmental stress tolerance and also throws light on ROS and redox signaling, calcium signaling, and ABA signaling.

Keywords::

• Antioxidants
• ROS
• redox signaling
• calcium
• ABA

Acknowledgment

We also express sincere thanks to the anonymous reviewers for constructive comments and kind guidance. The authors apologize for not citing all the authors of original publications because of space limitations.

Declaration of interest

We gratefully acknowledge Council of Scientific and Industrial Research (CSIR), New Delhi, India for providing financial assistance.