Biochemical changes of common bean (Phaseolus vulgaris L.) to pretreatment with salicylic acid (SA) under water stress conditions

Salicylic acid (SA) is one of the important signal molecules which modulating plant responses to environmental stresses including drought. An experiment was therefore, conducted to evaluation the effect of exogenous SA on the lipid peroxidation, antioxidant enzymes activities and proline content of common bean under water stress conditions during 2011 in Iran. Results showed that drought increased membrane lipid peroxidation via increase of malondialdehyde (MDA) content as well as some antioxidant enzymes activities such as superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) and proline level. Nonetheless, seeds soaking in SA (especially 0.5 mM) alleviated drought injuries by way of decrease of lipid peroxidation through reduce of MDA content and further increase in antioxidant enzymes activities especially SOD and proline level. Results signify that exogenous SA could help reduce the adverse effects of drought stress and might have a key role in common bean tolerance to drought by decreasing oxidative damage via further activities of antioxidant enzymes and more proline accumulation.