Investigation of the salt tolerance by hydrogen peroxide pre-treatment on two eggplant (Solanum melongena L.) genotypes under in vitro conditions

Effects of H2O2 pre-treatment on fresh weight, membrane permeability, MDA, proline, ion, inner H2O2 contents and antioxidant enzyme activities were investigated in the callus tissues of two eggplant genotypes (salt sensitive; Artvin and salt tolerant; Mardin) cultured in saline conditions. For this purpose, calli were obtained from hypocotyl explants from 4-week-old seedlings germinated in vitro. Some of the calli were transferred to mediums containing control, 150 mM NaCl, 50 or 100 μM H2O2, and the others which were pre-treated with 48 hours 50 or 100 µM H2O2 were transferred to mediums containing 150 mM NaCl and all of them incubated during 24 hours. While fresh weight, K+ and Ca2+ contents were decreased on salt stressed groups, H2O2 pre-treatments reduced these negative effects of salt stress. Salinity increased Na+ contents, while H2O2 pre-treatments decreased Na+ contents and increased K+/Na+ ratio. Salinity increased membrane permeability, MDA and inner H2O2 contents, these negative effects were reduced by H2O2 pre-treatments. H2O2 pre-treatments enhanced antioxidant defence by increasing SOD and CAT enzyme activities and proline contents, The curative effects of H2O2 pre-treatment on parameters we investigated were found to be higher in the salt-sensitive genotype. It has been shown that the effects vary depending on concentrations and genotypes.