Effect of Nicotiana benthamiana exposed to long- or short-chain perfluoroalkyl substances: Levels, transfer and potential risk analysis

Background: Perfluoroalkyl substances (PFAS) can endanger human health through the food chain. However, the physiological mechanisms of crops exposed to PFAS are still unclear. Objectives: The physiology, phytotoxicity and accumulation of Solanaceae model crops Nicotiana benthamiana exposed to perfluorooctanoic acid (PFOA), hexafluoropropylene oxide-dimer acid (HFPO-DA) and their mixed contaminants have been studied. Results: (i) Biomass, relative electrical conductivity and catalase all decrease; (ii) Chlorophyll, peroxidase, hydrogen peroxide and malondialdehyde all increase; (iii) Superoxide dismutase and soluble sugar both increase and then decrease; (Ⅳ) The absorption and transport of K, Ca, Mg and Na are affected, particularly shoots; (V) PFOA has the highest toxicity and bioaccumulation. Conclusion: PFAS will damages the economic benefits of crops and people's health. So, its production and uses should be curtailed except for essential uses. Future direction: Substitute substances may be more harmful, so grouping strategies and evaluation framework should be established as soon as possible.