GSH–AsA Cycle-Mediated “Vaccine-like” Priming Induced by Low-Dose Polystyrene Nanoplastics Enhances Plant Stress Resilience

Abstract

Nanoplastics (NPs) pollution poses an increasing threat to agricultural sustainability, yet whether low-dose exposure can prime plant defense responses remains unexplored. Here, we demonstrate that low-dose polystyrene nanoplastics’ (PS–NPs) pretreatment (10 mg/L) alleviates growth inhibition caused by subsequent high-dose stress (50 mg/L) in tomato plants, evidenced by restored photosynthetic homeostasis (Fv/Fm: 0.82 ± 0.02) and reduced oxidative damage. Integrated multiomics analysis identified the GSH–AsA cycle as the core regulatory hub. Pretreatment reprogrammed this cycle through transcriptional upregulation and enhanced enzyme activities, ensuring efficient reactive oxygen species scavenging and redox homeostasis. Molecular docking simulations revealed that PS-NPs exhibit high binding affinity to catalytic sites of key enzymes. These findings reveal a GSH–AsA cycle-mediated “stress priming” mechanism triggered by low-dose PS-NPs, providing new insights into plant adaptive responses to NPs stress under controlled conditions.