Plant growth was decreased by 100 mM NaCl treatment in
both low and high nitrogen medium. This was concurrent with
a decline in the activity of nitrate/nitrite reduction and ammonium
assimilation in the leaves, reflecting the decrease in soluble
protein contents. When nitrate was limited, plants were less
sensitive to NaCl than plants grown with high nitrate supply.
We assume that under nitrogen deficiency plants performed an
efficient growth activity to overcome salt stress effects. This
was displayed through (i) a sustain of adequate Chl contents,
(ii) higher aminating GDH activity and NADH-GDH/NADGDH
ratios, and (iii) an enhancement of carbon skeletons production
via deaminating GDH activity in the leaves and roots.
These results suggest that the GDH changes in vitro may be of
a physiological significance, and will be involved in the determination
of the plant response to NaCl stress.