Effect of salicylic acid pretreatment of barley seed on seedling growth, proline content and antioxidant enzymes activity under drought stress

One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development of them. It was found that seed priming improves some characteristics of seedling and plant. An experiment was conducted for evaluating the effect of seed priming by salicylic acid on some characteristics of barley seed at early growth stages, antioxidant enzyes activity and proline content under drought stress. The first factor was priming with salicylic acid (zero, 50, 100 and 150 ppm) and the second factor was three levels of drought (0, -6 and -12 bar). The results showed that SA pretreatment effect on germination percentage, germination rate, dry weight, protein, catalase, ascorbat peroxidase activity and proline content were significant. The interaction effect of stress  seed treatment on leaf number was not significant but the main factors were significant. The highest germination percentage (98.7), germination rate and seedling dry weight were found at 100 ppm concentrations of salicylic acid. Under drought stress conditions, protein content decreased but salicylic acid pretreatment increased the valuet. Also, drought stress conditions increased enzyme activity and proline content, but salicylic acid pretreatment decreased them.