Effects of salicylic acid on growth improvement and changes of biochemical parameters of wheat seedlings in cadmium stress

One of the strategies used to reduce the negative effects of various stresses on plants is the application of growth regulators such as salicylic acid. This study investigated the interaction between salicylic acid (0, 0.5 and 1 mM) and cadmium chloride (0, 100, 200 and 300 µM) on growth traits, photosynthetic pigments, antioxidant enzymes activity, relative water content, proline and glucose content in wheat seedlings. The results showed that cadmium stress reduced growth treats of plants from 30 to 50 percent compared to control untreated plants, significantly. Moreover, relative water content decreased by 7% and the chlorophylls a and b levels were about 2 times lower. Cadmium stress caused a three-fold increase in the activity of catalase and superoxide dismutase enzymes and also glucose levels dropped by 2 times. Salicylic acid spray had significant positive effects on growth traits of cadmium-stressed seedlings and between 20% to 60% increased these parameters. The relative water content of these seedlings also increased 2 times. Salicylic acid has increased the activity of antioxidant enzymes and increased levels of chlorophyll and glucose by over 40% compared to control plants. The results of this study showed that salicylic acid is effective in reducing the negative effects of cadmium stress by increasing the amount of chlorophyll, improving the activity of antioxidant enzymes and changing the amount of glucose in Wheat.