Metabolomics of wheat grains generationally-exposed to cerium oxide nanoparticles

This study investigated changes in metabolite compositions over three generation exposure of wheat (Triticum aestivum) to cerium oxide nanoparticles (CeO2-NPs) in low or high nitrogen soil. The goal was to determine if CeO2-NPs affects grains/seeds quality across generational exposure. Seeds from plants exposed for two generations to 0 or 500 mg CeO2-NPs per kg soil treatment were cultivated for third year in low or high nitrogen soil amended with 0 or 500 mg CeO2-NPs per kg soil. Metabolomics identified 180 metabolites. Multivariate analysis showed that continuous generational exposure to CeO2-NPs altered 18 and 11 metabolites in low N and high N grains, respectively. Interestingly, DNA/RNA metabolites such as thymidine, uracil, guanosine, deoxyguanosine, adenosine monophosphate were affected; a finding that has not been observed on DNA/RNA metabolites of plants exposed to nanoparticles. Nicotianamine, a metabolite playing crucial role in Fe storage in grains, decreased by 33% in grains continuously exposed for three generations to CeO2-NPs at high N soil. Notably, these grains also exhibited a concomitant decrease of 13-16% in Fe concentration. Together these changes suggest alterations in grain quality or implications in ecosystem processes (i.e., productivity, nutrient cycling, ecosystem stability) of progeny plants generationally-exposed to CeO2-NPs. (C) 2020. Published by Elsevier B.V.