Perfluorooctanoic acid (PFOA)-induced alterations of biomolecules in the wetland plant Alisma orientale

Perfluoroalkyl substances (PFASs) have been widely studied by researchers due to their environmental persistence, chemical stability and potential toxicity. Some researchers have reported the physiological and biochemical toxicity of PFASs on plants through traditional and innovative methods; however, the changes in biological macromolecules caused by PFASs are rarely studied. Here, Fourier transform infrared spectroscopy (FTIR) was used to study how exposure to perfluorooctanoic acid (PFOA) alters the structure and function of biomolecules of the wetland plant Alisma orientale. Biomass results showed that PFOA had negative effects on plant growth. FTIR results showed that PFOA could result in changes in the structures, compositions, and functions of lipids, proteins and DNA in plant cells. In the treatment groups, the ratios of CH3 to lipids and carbonyl esters to lipids increased compared with the control, while the ratios of CH2 to lipids and olefinicCH to lipids decreased, which indicated lipid peroxidation caused by PFOA exposure. Changes in the compositions and secondary structures of proteins were also found, which were indicated by the decreased ratio of amide I to amide II and the increased ratio of β-sheet to α-helix in the treatment groups compared to the control. Moreover, PFOA affected the composition of DNA by promoting the B- to A-DNA transition. These results showed that the mechanism of PFOA toxicity toward plants at the biochemical level could be illustrated by FTIR.