Abstract: As a category of emerging contaminants with global distribution, microplastics occur frequently in terrestrial ecosystems, including agricultural soils. Available evidence indicates that microplastics can alter soil physicochemical properties, and affect soil biota, plant performance, and ecosystem functions. As the most ubiquitous plant symbiotic fungi in soils, arbuscular mycorrhizal (AM) fungi can enhance host plant stress resistance through multiple mechanisms and play a critical role in maintaining ecosystem stability. This review synthesizes current research advances in the interactions between microplastics and AM fungi. Microplastics in soil can directly affect AM fungi through adsorption and absorption, or by releasing co-contaminants, and indirectly influence fungal colonization and community structure by altering soil properties (e.g., pH, nutrient availability), pollutant speciation and toxicity, microbial community composition and activity, and plant performance. On the other side, AM fungi exhibit strong tolerance and resilience to microplastics, and may alleviate negative impacts of microplastic contamination on plant and soil environment through multiple pathways, such as improving soil structure，mitigating plant nutrient limitations caused by microplastics, immobilizing microplastics via fungal structures (e.g., extraradical hyphae) to reduce their uptake and translocation by plants. Overall, the interactions between microplastics and AM fungi vary with microplastic characteristics (e.g., type, dose, size, and shape), plant species, soil properties, and exposure conditions, as a result it is still difficult to reach general conclusions. Finally, based on identification of current knowledge gaps, future research priorities are proposed to establish reliable quantitative method for microplastics in the soil plant systems, to assess the ecotoxicological effects of microplastic metabolites and composite pollution on AM fungi, and to reveal the influences of AM fungi on environmental behavior of soil microplastic and its ecological impacts, which will provide theoretical and technical support for the application of mycorrhizal technology to tackle soil microplastic pollution problems.

Key words: emerging contaminants, ecological functions, global change, environmental stress, soil pollution