Physiological and proteomic analyses reveal the effect of CeO₂ nanoparticles on strawberry reproductive system and...

With the rapid development of nanotechnology, the environmental impact assessment of nanoparticles (NPs) becomes a pressing problem to ensure the environmental safety and human health. However, the roles of CeO₂ NPs on the development of crop reproductive system and fruit quality are largely unknown. Herein, strawberry (Fragaria × ananassa Duch.) plants were exposed to CeO₂ NPs at 0-115 mg/L. The reduced generation of stolon, increased pollen numbers and germination rate of pollen grains, as well as the elongation of pollen tubes contributed to the enhanced yield of strawberry upon CeO₂ NP exposure (6-115 mg/L). Furthermore, the fruit quality was improved by increasing total phenols, vitamin C, amino acids, and protein contents. More importantly, even at 115 mg/L treatment, fruit Ce contents (4.4 mg/kg) did not exceed the Ce mean oral reference dose of humans. Finally, label-free proteomic results disclosed that differentially expressed proteins related to malate were down-regulated, and the differential regulation of sugar-associated proteins suggested the changes in sugar composition. The significantly different expression of ascorbate and glutathione related proteins exhibited the increased antioxidant capacity of fruits. The findings in the present study provide new perspectives for understanding the potential risk posed by NPs in the environment.