Interactive Effects of Cinnamic Acid and Water Stress on Wheat Seedlings

Abstract

In the present study we compared the effects of allelochemical with water stress (WS) on growth, biochemical parameters and responses of antioxidative enzymes in wheat seedlings. The wheat seedlings were treated with 0.5, 1.0 and 1.5 mM concentrations of cinnamic acid (CA) with and without water stress by withholding water supply for 5 days. Leaf water status, photosynthetic pigments, protein content, amount of proline and nitrate reductase (NR) and antioxidant enzymes activities were examined. CA resulted in reduction of seedling height with drastic decrease in stressed seedlings. The combined treatments CA+WS further decreased the seedling height. The same result was registered for seedlings dry weight, relative water content and pigment and protein contents. Total soluble sugar content and nitrate reductase activity were variedly affected under all treatments. Proline content and lipid peroxidation increased. Activity of superoxide dismutase increased significantly (less than 0.05) while catalase P activity was lower in all treatments. Ascorbate peroxidase and guaiacol peroxidase activities were higher as compared with catalase which showed protection of wheat seedlings from oxidative stress. Water stress elevated the toxic effect of allelochemical.