and leaf extracts alleviate arsenic toxicity by reducing arsenic uptake and improving antioxidant system in rice seedlings.

In the present study the potentials of aqueous extracts of the two plants, neem () and Tulsi () were examined in alleviating arsenic toxicity in rice ( L.) plants grown in hydroponics. Seedlings of rice grown for 8 days in nutrient solution containing 50 μM sodium arsenite showed decline in growth, reduced biomass, altered membrane permeability and increased production of superoxide anion O ), HO and hydroxyl radicals (OH). Increased lipid peroxidation marked by elevated TBARS (thiobarbituric acid reactive substances) level, increased protein carbonylation, alterated levels of ascorbate, glutathione and increased activities of enzymes SOD (superoxide dismutase), CAT (catalase), APX (ascorbate peroxidase) and GPX (glutathione peroxidase) were noted in the seedlings on As treatment. Exogenously added leaf aqueous extracts of (0.75 mg mL, w/v) and (0.87 mg mL, w/v) in the growth medium considerably alleviated As toxicity effects in the seedlings, marked by reduced As uptake, restoration of membrane integrity, reduced production of ROS, lowering oxidative damage and restoring the levels of ascorbate, glutathione and activity levels of antioxidative enzymes. Arsenic uptake in the seedlings declined by 72.5% in roots and 72.8% in shoots, when extract was present in the As treatment medium whereas with extract, the uptake declined by 67.2% in roots and 70.01% in shoots. Results suggest that both and aqueous extracts have potentials to alleviate arsenic toxicity in rice plants and that can serve as better As toxicity alleviator compared to .