Effects of 28-homobrassinolide on Seedling Growth, Lipid Peroxidation and Antioxidative Enzyme Activities under Nickel Stress in Seedlings of Zea mays L.

The effects of 28-homobrassinolide (28-homoBL) on seedling growth, lipid peroxidation and antioxidative enzyme activities under Nickel (Ni) stress in the seedlings of Zea mays L. (var. Partap-1) were studied. The surface sterilized seeds of Zea mays were given treatments of different concentrations of 28-homoBL (10-4, 10-6 and 10-8 mM) and heavy metal Ni (0.5, 1.0, 1.5 and 2.0 mM) in combination for 7 days. The activities of superoxide dismutase (EC 1.15.1.1) catalase (EC 1.11.1.6), ascorbate peroxidase (EC 1.11.1.11), guaiacol peroxidase (EC 1.11.1.7) and glutathione reductase (EC 1.6.4.2) of 7-days old seedlings were analyzed. It was observed that 28-homoBL reduced the toxicity of heavy metal on seedling growth considerably and also influenced protein content. Lipid peroxidation level was significantly increased under heavy metal treatments alone but lowered with 28-homoBL applications revealing less oxidative damage. 28-homoBL treatments expressed anti-stress activity by regulating the activities of antioxidative enzymes. It was observed that activities of all antioxidative enzymes increased except for superoxide dismutase as compared to control.