Role of Ascorbate Peroxidase in Ascorbate‐glutathione Pathway for Stress Tolerance

Abstract

Abstract Under both normal and stressful circumstances, plants produce reactive oxygen species (ROS). However, when environmental conditions are too unfavourable, excessive ROS is produced and the antioxidative defence mechanisms cannot handle the high amounts of ROS, which results in plant damage. The antioxidant defence system's enzymatic and non‐enzymatic components detoxify and scavenge ROS to lessen their harmful effects. The ascorbate‐glutathione (AsA‐GSH) route, also referred to as the Asada‐Halliwell pathway, entails four enzymes that are essential for the detoxification of ROS: AsA peroxidase (APX), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and GSH reductase (GR). These enzymes work in conjunction with other plant defence mechanisms in addition to detoxifying ROS to shield plants from different abiotic stress‐related harms. Numerous studies on plants have shown that the up‐regulation or overexpression of these antioxidant enzyme genes enhances the AsA and GSH levels in response to abiotic stresses and helps plants to lower ROS levels. This article outlines the role of APX as a crucial enzyme in the AsA‐GSH pathway and the capacity of plants to withstand abiotic stress.