Initial Sterilization of Soil Affected Interactions of Cerium Oxide Nanoparticles and Soybean Seedlings (Glycine max (L.) Merr.) in a Greenhouse Study

Cerium oxide nanoparticles (CeO2NPs) have exhibited strong impacts on many physiological and biochemical processes in agricultural crops. However, almost all previous studies directly linked the responses of plants to the impact of ENPs, ignoring the potential role of local organisms in the rhizosphere. The primary goal of this study was to assess the effects of the rhizosphere biocommunity on the interactions of CeO2NPs with soybeans, including CeO2NPs transformation in the rhizosphere and in plant tissues. Soybean seedlings grown in initially sterilized soil or unsterilized soil were exposed to different concentrations of CeO2NPs (0, 100, and 500 mg/kg) in a growth chamber for 27 days. Initial sterilization significantly affected the interactions of CeO2NPs and soybeans, compared with the unsterilized soil (p ≤ 0.05). For example, the net photosynthesis rate of soybean seedlings exposed to 100 mg/kg of CeO2NPs for 25 days was 122% higher in sterilized soil than in unsterilized soil. However, at 500 mg/k...