New Insights into the Accumulation, Transport, and Distribution Mechanisms of Hexafluoropropylene Oxide Homologues, Important Alternatives to Perfluorooctanoic Acid, in Lettuce (Lactuca sativa L.)

作者：Chen, Lei; Chen, Daijie; Zhou, Shunyi; Lin, Jieying; Liu, Yun; Huang, Xiongfei; Lin, Qingqi^*; Morel, Jean Louis; Ni, Zhuobiao; Wang, Shizhong^*; Qiu, Rongliang

来源：Environmental Science and Technology, 2023, 57(26): 9702-9712.

DOI：10.1021/acs.est.2c09226

• hexafluoropropylene oxide (HFPO) homologues
• lettuce(Lactuca sativa L
• )
• rhizosphere effect
• channel uptake
• tissue and subcellular distribution

Theaccumulation, transport, and distribution mechanismsof HFPO homologues in lettuce were investigated at the plant, tissue,and cell levels. HFPO-DA tended to accumulate in the edible parts,resulting in higher potential exposure risks. @@@ Hexafluoropropylene oxide (HFPO) homologues, which areimportantalternatives to perfluorooctanoic acid, have been frequently identifiedin crops. Although exposure to HFPO homologues via crops may posenon-negligible threats to humans, their impact on crops is still unknown.In this study, the accumulation, transport, and distribution mechanismsof three HFPO homologues in lettuce were investigated at the plant,tissue, and cell levels. More specifically, HFPO trimer acid and HFPOtetramer acid were primarily fixed in roots and hardly transportedto shoots (TF, 0.06-0.63). Conversely, HFPO dimer acid (HFPO-DA)tended to accumulate in lettuce shoots 2-264 times more thanthe other two homologues, thus resulting in higher estimated dailyintake values. Furthermore, the dissolved organic matter derived fromroot exudate enhanced HFPO-DA uptake by increasing its desorptionfractions in the rhizosphere. The transmembrane uptake of HFPO homologueswas controlled by means of a transporter-mediated active process involvinganion channels, with the uptake of HFPO-DA being additionally facilitatedby aquaporins. The higher accumulation of HFPO-DA in shoots was attributedto the larger proportions of HFPO-DA in the soluble fraction (55-74%)and its higher abundance in both vascular tissues and xylem sap. Ourfindings expand the understanding of the fate of HFPO homologues insoil-crop systems and reveal the underlying mechanisms of thepotential exposure risk to HFPO-DA.

• 单位
  华南农业大学; 中山大学; 广东省农业科学院