The combined effect of cadmium
stress (0,5 mM Cd(NO 3)2) and salt stress (100 mM
NaCl) on growth, lipid peroxidation and activities of some antioxidant
enzymes were studied in soybean (Glycine max L. Merr.) leaves. Shoot
lenghts were not changed under all groups. But fresh and dry weight
were decreased under salt treatment alone and Cd treatment alone. The
decrease was more in the group of combined of Cd and salt treatment.
Although APX activity increased under salt treatment alone and combined
of Cd and salt treatment, GR activity increased under Cd treatment
alone and combined of Cd and salt treatment. Nevertheless DHAR activity
increased only in combined of Cd and salt stress. MDA content increased
under all groups but it was more in the combined of Cd and salt stress
which indicates that salinity is more harmful with cadmium stress in
soybean plants. Thus, it was concluded that some of antioxidant enzymes
(APX, GR, DHAR) increased their activity under combined of Cd and salt
treatment but they were not efficient to protect oxidative damage from
soybean plants by alleviating the lipid peroxidation.
Key
words: cadmium; salt stress; soybean; antioxidant enzymes; Glycine max L. Merr.
