Uptake, translocation and metabolism of 8:2 fluorotelomer alcohol in soybean (Glycine max L. Merrill)

The biotransformation of fluorotelomer alcohols (FTOHs) are widely considered as sources of environmentally persistent perfluorocarboxylic acids (PFCAs). However, degradation of 8:2 FTOH [F(CF2)8CH2CH2OH] by plants has not... [ view full abstract ]

The biotransformation of fluorotelomer alcohols (FTOHs) are widely considered as sources of environmentally persistent perfluorocarboxylic acids (PFCAs). However, degradation of 8:2 FTOH [F(CF2)8CH2CH2OH] by plants has not been studied. In the present study, a hydroponic experiment was conducted to investigate the uptake, translocation and metabolism of 8:2 FTOH in soybean (Glycine max L. Merrill). The kinetic and concentration profiles of metabolites in different soybean tissues were monitored over 144 hours. Results showed that 8:2 FTOH could be fast taken up by soybean roots, translocated to soybean shoots and leaves, and metabolized into liable intermediates, including 8:2 FTCA [F(CF2)8CH2COOH], 8:2 FTUCA [F(CF2)7CF=CHCOOH] and 7:2 sFTOH [F(CF2)7CHOHCH3], which were subsequently biotransformed to 7:3 FTCA [F(CF2)7CH2CH2COOH] and PFOA [F(CF2)7COOH] in all tissues of the plant. At the end of the experiment, 7:3 FTCA and PFOA were the main metabolites, and accounted, respectively, for 47.5 % and 21.3 % of the total amount of degradation products detected in soybean tissues. More PFOA was detected in soybean leaves than 7:3 FTCA, which was the predominant compound in soybean roots and stems. The activities of some enzymes, such as alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH) and glutathione S-transferase (GST) in soybean roots over different exposure times were also investigated. This study provides important information for better understanding of plant uptake, transformation and metabolism of FTOHs and fluorotelomer-based compounds.