1Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, BHU, Varanasi-221 005, Uttar Pradesh, India.
2Faculty of Agricultural Sciences, GLA University, Mathura-281 406, Uttar Pradesh, India.
3Department of Genetics and Plant Breeding, MS Swaminathan School of Agriculture, Centurion University of Technology and Management, Paralakhemudi-761 211, Odisha, India.
4Division of Vegetable Production, ICAR-Indian Institute of Vegetable Research, Jakhini (Shahanshahpur), Varanasi-221 305, Uttar Pradesh, India.
5Department of Home Sciences, Government P.G. College, Joshimath-246 443, ChamoliUttarakhand, India.
6ICAR-Indian Agricultural Statistics Research Institute, New Delhi-110 012, India.
7Department of Natural Resource Management, College of Forestry, BUAT, Banda-210 001, Uttar Pradesh, India.
8ICAR-National Institute of Seed Science and Technology, Mau-275 103, Uttar Pradesh, India.
*Corresponding Author: Sadhna Mishra, Department of Dairy Science and Food Technology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi-221 005, Uttar Pradesh, India. Email: sadhna.mishra@bhu.ac.in
Salinity stress is a major abiotic constraint limiting crop productivity worldwide, particularly in legumes such as mungbean (Vigna radiata L.). Brassinosteroids (BRs), especially 24-epibrassinolide (EBL), are recognized for their role in regulating plant growth and enhancing tolerance to abiotic stresses by modulating physiological, biochemical and antioxidant defense mechanisms.
The present investigation evaluated the ameliorative effects of EBL on two mungbean genotypes, HUM23 and HUM16, under salinity stress conditions. HUM23 and HUM16 were selected based on their contrasting responses to abiotic stress (Tolerant vs. sensitive, respectively). Seeds were pretreated with EBL at concentrations of 0.005 mM and 0.01 mM (Selected based on literature-reported effective dose ranges for legumes), followed by exposure to 100 mMNaCl. Biochemical parameters including leaf greenness index (SPAD), protein content, nitrate reductase (NR) activity, proline and hydrogen peroxide levels were analyzed along with antioxidant enzyme activities (SOD, APX, CAT) at 5, 10, 15, 30 and 50 days after sowing (DAS). Experiments were conducted at the Department of Plant Physiology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, during 2023-2024.
Salinity stress significantly reduced chlorophyll content, protein content and nitrate reductase activity, while markedly increasing hydrogen peroxide accumulation, indicating enhanced oxidative stress. Exogenous application of EBL mitigated the adverse effects of salinity by improving chlorophyll retention, protein synthesis and antioxidant enzyme activities, thereby reducing oxidative damage. Among the genotypes, HUM16 exhibited greater salinity tolerance when treated with 0.005 mM EBL, whereas HUM23 showed superior overall biochemical performance under both control and EBL-treated conditions.
Antioxidant enzymes, Brassinosteroids, Mungbean, Nitrate reductase, Proline, Salinity stress
