28-Homobrassinolide alleviates oxidative stress in salt-treated maize (Zea mays L.) plants

Abstract

The present investigation was undertaken to study the effects of 28-homobrassinolide on the activities of antioxidative enzymes such as superoxide dismutase (EC 1.15.1.1), guaiacol peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), glutathione reductase (EC 1.6.4.2) and ascorbate peroxidase (EC 1.11.1.11), as well as protein and malondialdehyde concentrations in 30-d-old plants of Zea mays L. grown under salt stress. The seeds were soaked in 28-homobrassinolide solutions (0, 10-8, 10-6 and 10 -4 mM) for 12 h and then sown in the field in a randomized block layout. The blocks were salinised with NaCl at concentrations of 0, 25, 50 and 75 mM. The activities of antioxidative enzymes and protein concentration increased in 28-homobrassinolide-treated plants. Despite the enhancement of enzyme activities under salt stress alone, lipid peroxidation increased and protein concentration decreased. However, pre-sowing treatments of 28-homobrassinolide further enhanced the activities of antioxidative enzymes in addition to lowering lipid peroxidation and increasing protein concentration, thus suggesting that 28-homobrassinolide can alleviate oxidative stress in salt-treated maize plants.