Behaviour of antioxidative enzymes and of soluble protein in wheat seedlings after lead-induced stress

The amplitude of antioxidative enzymatic response was investigated in Triticum aestivum cv. Maruca. Pb2+ was provided as solutions of lead acetate [Pb(C2H3O2)2.3H2O] and lead nitrate [Pb(NO3)2], at four concentrations (10, 25, 50, 100 μM) containing 2.07, 5.18, 10.36, respectively 20.72 μg ml-1 Pb2+. The results support idea that mainly superoxide dismutase and peroxidase are involved in the defence mechanism of wheat seedlings against Pb2+ toxicity, by scavenging reactive oxygen species. All Pb2+ concentrations enhanced SOD activity (the increase rates range between 24.59%-65.19%, for Pb2+ acetate, and between 20.88%-175.40%, for Pb2+ nitrate treated variants, comparatively to control). Pb2+ induced the decline of soluble protein level in all variants, indifferently of compound type and lead concentration