Physiological and Metabolic Responses of Wheat (Triticum aestivum L.) after One-Generation Exposure to Perfluorooctanesulfonic Acid (PFOS)

Abstract

The pattern of plant responses, particularly on the seeds/grains metabolite profile, after generational exposure to contaminants is not well documented. Seeds from wheat cultivated in soil amended with PFOS at 0 and 25 mg/kg in the first generation were grown in clean soil to produce daughter plants and seeds in the second generation and assigned treatment combinations of 0–0 mg/kg PFOS and 25–0 mg/kg PFOS. Plant stress and responses including growth and biomass production, chlorophyll content, lipid peroxidation, and enzyme activity were measured over a short exposure period (21 days growth period). Biomass yields, elemental concentration, and grain metabolites were also measured after a long exposure period (92 days growth period). The daughter plants exhibited decreased chlorophyll content and lipid peroxidation in a short exposure period. The elemental concentrations were mostly not affected except for changes in microelements, except B, in the grains. In the metabolomics analysis, grains harvested from plants previously exposed to PFOS (i.e., 25–0 mg/kg PFOS) showed increased abundances of sucrose, linolenic acid, tryptophan, inositol-4-monophosphate, and ferulic acid, perhaps in response to adaptation to former stress. The current findings seem to suggest that one-generation exposure to PFOS does not cause detrimental effects on the next generation after the cessation of exposure. The results provide insights into the effects of generational exposure of plants to PFOS.