Soil-derived protein corona modulates the behavior and biological effects of nanoplastics in rice.

Nanoplastics are emerging contaminants widely distributed in terrestrial environments. Upon entering soil, their surfaces can adsorb soil-derived proteins to form protein coronas, potentially altering their environmental behavior and biological effects. In this study, amino- and carboxyl- modified polystyrene nanoplastics (PSN and PSC) were incubated with soil-extracted proteins to construct protein coronas, and their uptake, distribution, and phytotoxicity were evaluated in rice. Under controlled exposure conditions, with corona-coated nanoplastics exhibiting distinct growth inhibition patterns compared with pristine nanoplastics. After exposure, PSC with protein corona (PSC-PC) exhibited the strongest toxicity, reducing root length, leaf length, and total fresh weight by 18.50%, 23.73%, and 11.95%, respectively. Protein corona formation modulated nanoplastic-induced oxidative stress responses. Transcriptomic analysis identified differential expression and enrichment of genes associated with PRR/LRR-RLK-related perception, Ca2+- and MAPK-related signaling, and stress- and hormone-responsive transcriptional programs. Distinct surface functional groups induced divergent molecular responses. PSN-PC was associated with defense- and stress-related transcriptional responses and downregulation of genes involved in energy metabolism, whereas PSC-PC was associated with more pronounced alterations in growth-related processes. Collectively, these findings demonstrate that soil-derived protein coronas can modify nanoplastic behavior during plant uptake and alter their phytotoxic effects, highlighting the importance of considering protein corona formation in environmental risk assessments of nanoplastics.