TiO₂ and ZnO Nanoparticles Toxicity in Barley (<i>Hordeum vulgare</i> L.)

Abstract

In this study, the effects of TiO 2 and ZnO nanoparticles (0, 5, 10, 20, 40, and 80 mg kg −1 ) on seed germination, root elongation, chlorophyll content, and the activities of antioxidant enzymes of barley ( Hordeum vulgare L.) are studied. The number of seeds germinated and roots elongated in germinated plants (tillering stage) are determined on day 7. Seedlings are transferred to pots containing 50 g turf and grown for 21 days. Antioxidant levels (superoxide dismutase, catalase, ascorbate peroxidase, glutathione, and proline) are determined on day 21 after planting. The results shows that seed germination and root elongation are not significantly affected by types and concentrations of ZnO and TiO 2 nanoparticles. However, the antioxidant enzyme activities are diversely affected. Furthermore, the results also show that the ZnO nanoparticles are more toxic to barley plants than the TiO 2 nanoparticles.