Auxin and Sodium Nitroprusside Effects on Wheat Antioxidants in Salinity

The effect of indole butyric acid (IBA) as auxin hormone and sodium nitroprusside (SNP) on total antioxidant, carotenoid, total phenolic compounds, catalase activity and shoot dry weight in wheat (Triticum aestivum L. cv. Chamran) under 50 and 100 mM NaCl as salt stress were studied. These two experiments were done separately and in a completely randomized design, in three replications. Indole butyric acid in three levels and sodium nitroprusside in one level were used as spray on the plant to compare their effects. According to the results, the amount of carotenoid, total phenolic compounds, antioxidants and catalase activity have increased but shoot dry weight have decreased by either salinity alone and/or combined with IBA and SNP in our experiments, comparison to the control but with different level. None of the carotenoid, total phenolic compounds, antioxidants, catalase activity and shoot dry weight showed significant changes when indole butyric acid or sodium nitroprusside treatment were induced alone that shows their nontoxicity for seedlings. In connection with indole butyric acid or sodium nitroprusside treatment, these compounds appears to alleviate the stress conditions by showing significant decreasing of carotenoid, total phenolic compounds, antioxidants and catalase activity and significant increasing of shoot dry weight. Our results showed that IBA and SNP had the same effects in salt stress, so in salt stress conditions it is recommended to use IBA for crop and non-crop plants and SNP for only not edible plants.