Abstract:
Six varieties of soybean
(Glycine max L.) plants were grown for 30
days under three levels of sea salt salinity
(0.0, 8.0 and 16.0 mS/cm2) for studying the
effect of sea salt on uptake of nitrate and
response of the antioxidant system for these
salinity doses. Salt treatments resulted in a
gradual decline in nitrate uptake by
increasing sea salt concentration, which
mean that this will bring negative
consequences on nitrogen assimilation.
However, salt treatments induced the
accumulation of hydrogen peroxide and
glycinebetaine in the leaves of all soybean
verities as an adaptive strategy to cope with
salt stress. On the other hand, there was a
differential response in phenolic compounds
among soybean verities as a function of salt
concentration and the studied variety, which
means there has a decline in phenolics under
salt stress in the varieties Crawford, G21,
G22 and G83, but in contrary in G35 and
G82, phenolics has accumulated in response
to salinity. Isozymes electrophoretic
banding showed changes in peroxidase
activity with sea salt, however superoxide
dismutase showed stability in number and
intensity of bands with salt treatments.
Esterase enzyme was more sensitive to
salinity and showed a gradual decline in
activity by increasing salt concentration.
