Contrastive response of Brassica napus L. to exogenous salicylic acid, selenium and silicon supplementation under water stress

Abstract

The present research was designed to determine the effects of exogenous salicylic acid (SA), selenium (Se) and silicon (Si) on the resistance of canola (Brassica napus L. cv Okapi) seedlings to salt stress. Foliar application of SA (0.1 mM) in canola plants under drought stress for 25 days exhibited a significantly positive effect on shoot dry mass and raised the levels of total chlorophyll as well as boosting the activity of superoxide dismutase (SOD) and catalase (CAT). In addition, soil application of silicon (0.35 g Na2SiO3/kg soil) had ameliorative effects on canola root growth under drought. It is concluded that SA and Si enhanced the salt tolerance of canola by protecting the cell membrane against lipid peroxidation. However, the foliar application of Se (10 mg/l) had no ameliorative effects on canola growth and antioxidant capacity under drought stress, as could be judged by accumulation of malondialdehyde (MDA).

Keywords

• Antioxidant defense system
• canola
• exogenous salicylic acid
• drought stress
• sodium selenate