Accumulation of class-III type of boiling stable Peroxidases in response to plant growth hormone ABA in Triticum aestivum cultivars

Abstract

Abscisic acid (ABA) is a key plant growth and stress hormone involved in many biological processes. It has been shown to be involved in Reactive Oxygen Species (ROS) generation. Class-III Peroxidases (PODs) are known to maintain oxidative stress induced-ROS at sub-lethal levels in plants under abiotic stress conditions, but, studies documenting how ABA regulates boiling stable class-III PODs are still a matter of conjuncture. In this study, the ABA-induced changes on ROS and ROS scavenging class III boiling stable POD were studied in the embryos of different cultivars of wheat. Simultaneous analysis of ROS contents, activities of ROS-scavenging class- III boiling stable POD enzymes gave an integrative view of physiological state and detoxifying potential under conditions of sensitivity and tolerance. Indices of oxidative stress viz., superoxide radical and H 2 O 2 content increased under ABA treatment in a genotype dependent manner. It was observed that cultivars :PBW 550, HD 2967 and PBW 621 have more efficient mechanism to scavenge ROS species as shown by increase in BsPOD activity accompanied by enhanced expression of boiling stable POD isoenzymes. Based on results it can be inferred that embryos of cvs. PBW 550, HD 2967 and PBW 621 have more capacity to perform biological antioxidative reactions to combat ABA-induced oxidative stress.