Exogenous Salicylic Acid and Cytokinin Alter Sugar Accumulation, Antioxidants and Membrane Stability of Faba Bean

Abstract

This research was conducted in a greenhouse to evaluate the effects of exogenous application of salicylic acid (SA) (1 mM) and 6-benzylaminopurine (BAP) (50 μM) on physiological performance of faba bean (Vicia faba) under different levels of NaCl salinity (0, 4, 8 and 12 dS/m). The experiment was arranged as factorial on the bases of randomized complete block design in three replications. Leaf Na+ content, root and leaf soluble sugars, antioxidant enzymes activities such as catalase (CAT), ascorbate peroxidase (APX), superoxide dismutase (SOD) and lipid peroxidation increased, but K+, K+/Na+ and membrane stability index (MSI) decreased as a result of salt stress. However, foliar sprays of BAP and particularly SA reduced Na+ content and lipid peroxidation, while enhanced the K+ content, K+/Na+, soluble sugars, antioxidant enzymes activities and MSI under different levels of salinity. It was, therefore, concluded that exogenous application of these growth regulators (GR) can considerably improve salt tolerance and physiological performance of faba bean.