Effect of Heat Stress on Antioxidative Defense System and Its Amelioration by Heat Acclimation and Salicylic Acid Pre-Treatments in Three Pigeonpea Genotypes
Kaur Navneet1, Kaur Jagmeet2,*, Grewal Satvir Kaur3, Singh Inderjit2
1Department of Botany, Punjab Agricultural University, Ludhiana-141004, Punjab, India
2Department of Plant Breeding and Genetics, Punjab Agricultural University, Ludhiana-141004, Punjab, India
3Department of Biochemistry, Punjab Agricultural University, Ludhiana-141004, Punjab, India
*Author for correspondence: E-mail: firstname.lastname@example.org
Online published on 22 August, 2019.
In this study, effect of heat stress on antioxidative defense system and its amelioration by heat acclimation and salicylic acid pre-treatments in three pigeonpea genotypes at seedling stage was analyzed. Heat acclimation (45°C for 3h) and salicylic acid (0.5 mM and 1 mM for 3h) pre-treatments were given to seven days old seedlings. Heat stress resulted in oxidative stress through the production of reactive oxygen species (ROS) mainly H2O2 and increased peroxidation of lipid membranes (MDA content). These pre-treatments conferred protection against heat stress through reduction in MDA and H2O2 content by means of induced adaptation effect and antioxidant activity which enhanced tolerance towards heat stress. Antioxidative defense system was observed through increased activity of CAT (average 1.02 fold increase in heat acclimated, 0.77 fold in 0.5 mM SA and 1 fold in 1 mM SA) and POX (average 1.30 fold increase in heat acclimated, 1.24 fold in 0.5 mM SA and 1.37 fold in 1 mM SA) in all genotypes. Among the three genotypes, AL 1931 performed best and acquired maximum thermotolerance.
Pigeonpea, heat acclimation, salicylic acid, antioxidative defense system, oxidative stress.