Divergent Responses of Rice ( Oryza sativa L.) Cell Wall to Cd Phytotoxicity Affected by Continuous Nanoplastics Stimulation

L.), with a particular focus on the root CW. Our results reveal a dosage-dependent "double-edged sword" effect: low-dosage NPs immobilized 72.3% of Cd in the root, while high-dosage NPs disrupted CW integrity, facilitating 34.4% Cd translocation to shoots and exacerbating phytotoxicity. Low-dosage NPs exposure activated carbohydrate and lignin metabolic pathways, increasing the CW thickness by 46.7% and limiting Cd entry. Conversely, high-dosage exposure triggered oxidative stress, impairing CW biosynthesis, causing structural collapse, and increasing CW permeability, thus enhancing Cd uptake. This research improves our understanding of NPs-heavy metal interactions and provides insights for agricultural risk assessment amidst rising plastic pollution.