Superoxide dismutase catalyses the dismutation of
superoxide radicals to H2O2 and O2, and constitutes the
most important enzyme in cellular defence because its
activation directly modulates the amounts of O2
– and H2O2
(Foyer & Noctor, 2000). Leaf SOD activity in both NaClstressed
and prestressed/recovered cowpea was not significantly
different when compared with control throughout
the experimental period (Fig. 4c). This is in agreement with
severe damage to the membrane integrity and lipid peroxidation
of cowpea leaves, probably involving action of superoxide
radicals. Contrary to our results, some reports have shown
that salt stress induces an increase in SOD activity, and
this has frequently been correlated with salt tolerance