Publications

The harmful effects of micro(nano)plastics (MNPs) on agroecosystems are becoming more concerning. However, little is known about how MNP size and leaf features affect MNP bioaccumulation, cellular localisation, and translocation.In this study, foliar exposure to 80 nm and 500 nm polystyrene (PS) MNPs in soil-grown maize and soybean plants was studied. Trichomes and smaller sizes increased PS MNP deposition on crop leaf surfaces. 500 nm PS was mostly on the leaf epidermis and little in the apoplast or cytoplasm, regardless of crop species. 80 nm PS entered maize leaves via stomatal and cuticular routes, while soybean leaves were penetrated by a single cuticular pathway owing to trichomes. After that, 80 nm PS emerged in the apoplast and cytoplasm and entered the vasculature via apoplastic and symplastic routes. Interaction of 80 nm PS with n-alkanes and esters showed that placing 80 nm PS on leaves caused a remarkable ‘wax degradation’, i.e., phase transition of wax ultrastructure from crystalline to amorphous. These findings give a scientific basis for understanding MNPs’ environmental behaviours and physiological impacts in air-vegetation systems, which may be used to assess food safety hazards.