Evaluation of post-germinative lipid peroxidation and enzymatic antioxidant potential in lead absorbing oat (Avena sativa) seedlings.

The objective of the present research was to study the impact of lead (Pb) on growth, metal uptake and antioxidative potential of oat seeds under metal stress. To achieve these objectives, few experiments were conducted to assess the effect of this particular metal on various anti-oxidative enzymes, during initial metabolism after germination, in presence of lead. Pb is not an oxido-reducing metal, the oxidative stress induced by Pb in growing oat seedlings appears to be an indirect effect of Pb toxicity, leading to production of ROS with simultaneous decrease in tissue levels of superoxide dismutase and catalase. Content of free radical like superoxide anion and metabolite such as H2O2 were found to be more in plumule as compared to radical and endosperm of oat seedling. In response to various concentrations of lead ranging from 25-400 ppm, activities of peroxidase, glutathione peroxidase and ascorbate peroxidase were induced in plumule, radical and cotyledon on the 3rd, 6th and 9th days after germination. Growth parameters like length, fresh weight and dry weight were substantially affected in addition to reduced germination upto 49% only. The results indicated that even at the lowest concentration tested, a low inhibition of growth was obtained.