A Comparative Study on the Effects of Nano- and Microplastics on Nutrient Element Accumulation and Physiological Performance in Arugula (Eruca sativa L.): Implications for Food Crop Safety

Plastic pollution in irrigation water poses an emerging threat to agricultural systems. This study compared the effects of nanoplastics (NPs, ۲۴۸ nm) and microplastics (MPs, ۳۴ μm) on arugula (Eruca sativa L.) exposed to ۱۰–۱۰۰ mg/L concentrations justified by Tigris River contamination modeling. Plants were cultivated for ۶۵ days in controlled chambers; particle characterization employed Py-GC/MS, μ-Raman, TEM-EDS, and confocal microscopy. Nitrogen was quantified by Kjeldahl digestion, and other minerals were quantified by ICP-OES. Statistical analysis used linear mixed-effects models with Benjamini–Hochberg correction. Nanoplastics induced greater nutrient depletion than microplastics: at ۱۰۰ mg/L, nitrogen declined ۵۰.۹% (NP) vs. ۳۷.۳% (MP), iron ۵۵.۴% (NP) vs. ۳۴.۸% (MP) (P < ۰.۰۰۱). Oxidative stress markers (H₂O₂, MDA) increased ۱۸۹% and ۲۰۱% under NP vs. ۱۵۶% and ۱۶۸% under MP (P < ۰.۰۰۱). Although MP root accumulation (۴۲.۴ mg/kg) exceeded NP accumulation (۱۴.۴ mg/kg) threefold, NPs proved more phytotoxic. Subcellular imaging revealed NP penetration into chloroplasts and mitochondria; MPs remained extracellular. Fresh biomass declined ۵۸.۲% (NP) vs. ۴۱.۷% (MP) (P < ۰.۰۰۱). Antioxidant enzyme upregulation was stronger under NP exposure but insufficient to prevent oxidative damage. These findings demonstrate that nanoplastics pose a greater physiological threat to arugula than microplastics through organellar penetration and cellular dysfunction, despite lower tissue accumulation. Results highlight the urgent need to incorporate nano-scale particles into irrigation water quality standards and treatment technologies.

کلیدواژه ها:

Nanoplastics ، microplastics ، Arugula ، mineral uptake ، Oxidative stress ، Food safety