Generational Exposures to Cerium Oxide Nanoparticles and Perfluorooctanesulfonic Acid Affect the Performance of Daughter Plants

The effects of parental stress on the performance of next generation exposed to another contaminant were investigated. Wheat was exposed to cerium oxide nanoparticles (CeO2-NPs) in first and second generations and exposed to perfluorooctanesulfonic acid (PFOS) in the third generation. Phenotypic or metabolic responses were assessed at 21-day (short-term exposure) or 90-day (long-term exposure) exposure periods. Biomass production, chlorophyll content, enzyme activity, and membrane damage were measured at short-term exposure, while elemental and PFOS concentrations, and grain metabolites were analyzed in long-term exposure. Results showed that continued exposures to CeO2-NPs and PFOS enhanced chlorophyll content but reduced concentrations of important macro- and micro-elements in the grains of daughter plants. PFOS was accumulated in the grains of wheat while metabolomic analysis revealed that grain metabolite composition was significantly altered. Continued exposure to CeO2-NPs and PFOS decreased the abundances of most metabolites (22 out of 34). Consistent and repeated previous exposures to CeO2-NPs also had progressively decreased the concentrations of sucrose-6 phosphate, adenine, and other organic acid metabolites. The findings suggest that prior generation’s exposure could still influence succeeding progeny generations via invisible changes in metabolite and elemental compositions of grains.