Unraveling the Multilevel Phytotoxicity of Micro(nano)plastics and Their Combined Effects with Antibiotics in Soil-Plant Systems: Internalization, Mechanisms, and ARG Dissemination

Micro(nano)plastics (MNPs) often coexist with antibiotics in soil ecosystems via organic fertilizer applications. They can be taken up and accumulated by plants, especially food crops, thereby threatening food safety. Despite increasing global concern, the distinct phytotoxic mechanisms of MNPs and their interactive dynamics with antibiotics remain dispersed. First, the uptake, translocation, and distribution of MNPs in plants are systematically synthesized. Based on the clarification of plant phenotypic and physiological responses to MNP stress, the review assesses their biochemical and molecular mechanisms, ranging from oxidative stress and antioxidant defense to signal transduction and transcriptional regulation to metabolic trade-offs. After clarifying the physicochemical interactions and cotransport mechanisms between MNPs and antibiotics, the review elucidates their combined phytotoxicity and their crucial role in antibiotic resistance gene (ARG) transmission in soil-plant systems. Finally, we identify research gaps and propose future research directions, which will facilitate the evaluation of ecological risks and the formulation of environmental regulations for copollutants.