Evaluation of zinc accumulation potential of Hydrilla verticillata

Biofortification of foods with essential micronutrients and phytoremediation of the contaminated sites are the two sides of the same coin for metals like zinc. In the present study, Zn accumulation potential, growth and antioxidant status of Hydrilla verticillata (L.f.) Royle plants were studied upon supplementation of Zn (0–5 000 μM) for 2 and 7 d. At 5000 μM Zn, plants accumulated about 7.60 and 18.07 mg(Zn) g⁻¹(d.m.) after 2 and 7 d, respectively. Plants exposed to Zn concentrations up to 500 μM showed significantly increased contents of low molecular mass antioxidants and activities of antioxidant enzymes in comparison with controls. Only upon exposure of plants to 5 000 μM Zn, toxicity was observed after 7 d. Therefore, owing to their high Zn accumulation capacity, Hydrilla plants may be used both as a Zn source (via culturing in ca. 100 μM Zn supplemented nutrient medium) or as a phytoremediator.