Grandparental transfer of nanoplastics in pea plants (Pisum sativum): Transmission from soil to third generations

With the increase in micro- and nanoplastic abundance in the soil environment, there has been growing concern regarding the translocation of nanoplastics to the soil biota. To this end, this study aimed to determine the multigenerational transfer of nanoplastics in plants by chronic exposure to nanoplastics (200 nm, polystyrene). Only the first generation (F0) of pea plants was exposed to nanoplastics, and subsequent generations (F1 and F2) were replanted in clean soil without nanoplastics. Pea fruits and plants of the F2 generation were examined using confocal laser scanning microscopy and transmission electron microscopy. Green fluorescence of the nanoplastics was observed in contrast to the control. Nanoplastics were located in intracellular as well as intercellular spaces and enclosed within the endoplasmic reticulum and vacuoles. Nanoplastic fluorescence detected in F2 plants confirmed that nanoplastics can be transferred not just to daughter but also to third generations. Our results suggest that nanoplastics exposed to the first generation can be continuously transferred to subsequent generations and further emphasize that they can be continuously circulated in soil ecosystems. It also shows that nanoplastics can reach humans through food and calls for improved food safety measures against micro- and nanoplastics.