Influence of salicylic acid on growth and some biochemical parameters in a C 4 plant ( Panicum miliaceum L.) under saline conditions

Salt stress is considered as a restricting factor for plant products. Therefore, many compounds were applied to minimize the harmful effects of this stress. In this study, millet plants (Isfahan cultivar) were sprayed with 0.1, 0.3, 0.5 and 1 mM salicylic acid and then treated with 0, 150, 225 and 325 mM NaCl. Our results show that in plants not sprayed with salicylic acid but treated with NaCl, shoot length, wet weight of shoot and root, dry weight of shoot and free proline content of root significantly decreased but malondialdehyde and free proline content of leaves significantly increased. But in plants pretreated with salicylic acid, reduction in these parameters were moderate and 0.1 and 0.3 mM salicylic acid had better effect on these parameter. Therefore, we conclude that some concentration of salicylic acid could decrease harmful effects of NaCl in this plant. Key words: Millet, NaCl, salicylic acid, proline, malondialdehyde (MDA).