Soluble Proteins, Proline, Carbohydrates and Na⁺/K⁺ Changes in Two Tomato (Lycopersicon esculentum Mill.) Cultivars under in vitro Salt Stress

Abstract

The effect of NaCl stress on soluble proteins, proline, carbohydrates and Na⁺/K⁺ of two tomato (Lycopersicon esculentum Mill.) cultivars Isfahani and Shirazy were studied. Seeds were germinated on medium containing only water agar, then transferred to MS medium supplemented with different concentrations of NaCl (0, 40, 80, 120 and 160 mM) for 21 days. Increasing of salinity resulted in increasing of soluble proteins in stem and leaf of cv. Isfahani but decreasing in cv. Shirazy. Soluble proteins in roots of both cultivars showed some variations. When concentration of NaCl in the medium was increased proline contents of stem-leaf and roots in both cultivars increased significantly. However, cv. Shirazy showed higher amount of proline level. Proline content in stem-leaf in comparing with roots was higher in two cultivars. In response to increasing of salt concentration of the medium, the average amount of total carbohydrate in stem-leaf of cv. Shirazy increased but, in cv. Isfahani level of carbohydrate decreased. When explants form both cultivars were exposed to the higher concentration of salt the level of carbohydrate in roots increased. High-level salinity decreased the reduced sugars in both cv. either in stem-leaf or roots. Salt stress increased Na+ and decreased K⁺ content in both cultivars significantly.