Response of Strawberry Plant cv. 'Camarosa' to Salicylic Acid and Methyl Jasmonate Application Under Salt Stress Condition

The possible role of salicylic acid (SA) and methyl jasmonate (MJ) treatments on the physiology responses and growth of strawberry (Fragaria x ananassa) cv. 'Camarosa' subjected to the different levels of salinity stress were investigated. Root and shoot growth as well as their Na+/K+ ratio, photosynthetic-related factors, and activity of some important antioxidant enzymes were determined in the salt-treated plants. Results indicated that salt stress reduced plant performance especially at higher concentrations. By increasing the levels of salinity stress, fresh and dry weight of shoot and roots, net photosynthetic rate (Pn), and stomatal conductance (Gs) significantly decreased, whereas intercellular CO2 (Ci) increased. Application of exogenous SA and MJ significantly improved the plant physiological characters as well as fresh and dry weight of shoots and roots. Moreover, the ratio of Na+/K+ was elevated in the leaves and roots concomitantly with salinity levels, whereas SA and MJ treatments significantly reduced this ratio. Results of enzymatic assays showed that activity of ascorbate peroxidase, peroxidase, and superoxide dismutase enzymes increased in the salt-stressed plants. In addition, SA and MJ treatments reduced the destructive effects of salinity in strawberry plant. In general, among the tested concentrations, 0.5 mM SA and 0.25 mM MJ best increased the activity of antioxidant enzymes and hence alleviated the detrimental effects of salinity stress.