Microplastics enter strawberry fruit tissues directly through the epidermis

Plant absorption is critical for the introduction and transfer of numerous contaminants into food chains. Although microplastics (MPs) could be absorbed by plant leaves, direct evidence for their accumulation in edible fruit tissues remains limited. Here, the uptake and internalization of polystyrene microplastics (PS-MPs) with different particle sizes in strawberry fruit was investigated by fluorescence labelling and in-situ imaging. Micron (2 μm) and nano-sized (80 nm and 200 nm) fluorescently labelled plastic particles can be taken up by the strawberry (Fragaria × ananassa) fruit epidermis. The uptake pathways of PS-MPs are size-dependent: micron-sized MPs (2 μm) primarily enter through stomatal openings, whereas nano-sized particles (80 nm and 200 nm) can be internalized via both stomatal entry and endocytosis. The potential impacts of PS-MPs exposure on strawberry fruit quality were evaluated. Fruit-surface exposure to PS-MPs was associated with reduced fruit weight and increased acidity, indicating potential adverse effects on yield and flavor quality. Moreover, alterations in antioxidant composition were observed, indicating possible impacts on the nutritional characteristics of the fruit. Overall, these findings suggest that atmospheric MPs in agro-environments may represent an overlooked source of MP accumulation in fruit-bearing crops. This study offers new insights into the interactions between MPs and fruit-bearing crops and highlights the need to consider fruit tissues in assessments of dietary exposure to environmental MPs.