Trans-generational impact of cerium oxide nanoparticles on tomato plants.

Cerium oxide nanoparticles (CeO2-NPs) are increasingly used in polishing, engine enhancement agents and many other products. Even though the acute toxicity of CeO2-NPs to plants has been investigated, the long-term effects of CeO2-NPs in the environment are still unknown. The main objective of this study was to investigate whether the treatment of tomato plants with relatively low concentrations of CeO2-NPs (10 mg L(-1)) through their lifecycle would affect the seed quality and the development of second generation seedlings. The results indicated that second generation seedlings grown from seeds collected from treated parent plants with CeO2-NPs (treated second generation seedlings) were generally smaller and weaker, as indicated by their smaller biomass, lower water transpiration and slightly higher reactive oxygen species content. An interesting phenomenon noticed in the study was that the second generation seedlings grown from treated seeds developed extensive root hairs compared with the control second generation seedlings (seedlings grown from seeds collected from untreated parent plants) regardless of the treatment. Treated second generation seedlings also accumulate a higher amount of ceria than control second generation seedlings under the same treatment conditions even though such differences are not statistically significant.