气候变化领域集成服务门户

Ten agronomic plant species were exposed to different concentrations of nano-titanium dioxide (nTiO(2)) or nano-cerium oxide (nCeO(2)) (0 mu g/mL, 250 mu g/mL, 500 mu g/mL, and 1000 mu g/mL) to examine potential effects on germination and early seedling development. The authors modified a standard test protocol developed for soluble chemicals (OPPTS 850.4200) to determine if such an approach might be useful for screening engineered nanomaterials (ENMs) and whether there were differences in response across a range of commercially important plant species to 2 common metal oxide ENMs. Eight of 10 species responded to nTiO(2), and 5 species responded to nCeO(2). Overall, it appeared that early root growth may be a more sensitive indicator of potential effects from ENM exposure than germination. The observed effects did not always relate to the exposure concentration, indicating that mass-based concentration may not fully explain the developmental effects of these 2 ENMs. The results suggest that nTiO(2) and nCeO(2) have different effects on early plant growth of agronomic species, with unknown effects at later stages of the life cycle. In addition, standard germination tests, which are commonly used for toxicity screening of new materials, may not detect the subtle but potentially more important changes associated with early growth and development in terrestrial plants. Published 2016 Wiley Periodicals Inc. on behalf of SETAC.