Visual Tracking and Quantitative Analysis of Polystyrene Nanoplastics Uptake and Transport across Various Tomato Varieties

The mechanisms by which plants respond to microplastic pollution are still unclear. To identify resistant varieties for elucidating these mechanisms, this study investigated the differential accumulation and resistance of six tomato cultivars to polystyrene nanoplastics (PS-NPs). Significant varietal differences were observed. Heinz 1706 was the most resistant (13% growth inhibition), while Moneymaker was the most sensitive (32% inhibition). PS-NPs content was significantly lower in shoots than in roots. In stems and leaves, PS-NPs accumulated near the xylem, whereas in roots, they were distributed across all tissues. Translocation factors (TF) also varied, with Ailsa Craig having the highest TF (4.0%) and M82 having the lowest TF (0.89%). Correlation analysis revealed a strong negative relationship between root PS-NPs accumulation and plant growth. These findings provided key insights into microplastic accumulation and resistance factors in plants, forming the foundation for future molecular and physiological studies.