DIFFERENT RESPONSES IN ACCLIMATED AND NON-ACCLIMATED PROCESSES OF SOYBEAN LEAVES TO SALINITY

The aim of the study is to determine different responses, occurring during the process of acclimation and non-acclimation in soybean (Glycine max L. Merr.) leaves which was not investigated before. With this aim, relative water content (RWC), relative growth rate (RGR), shoot length, lipid peroxidation and the activity of some anti-oxidant enzymes ((catalase (CAT, EC 1.11.1.6) ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.8.1.7)) were reported. In the experiment, the first group was exposed to an acclimation treatment (plants were watered with 100 mM NaCl from germination to leaf stage) and a second group was given a non-acclimated treatment (plants were watered with dIH sub(2)O from germination to leaf stage). After that, both groups were watered with 200 mM NaCl in a Hoagland solution for 7 days). The product of lipid peroxidation, MDA content, was increased in both groups but it was more pronounced in the non-acclimated group. The activities of CAT, APX and GR increased significantly in both groups, but this increase was higher in the acclimated group. As a result, acclimation process to salt stress was beneficial for soybean leaves by protecting them from oxidative damage with lower MDA content and higher enzyme activities of CAT, APX and GR.