Effects of microplastic on soil ecosystems: a perspective from functional genes

The extensive production and persistence of microplastics (MPs) have resulted in their widespread accumulation in terrestrial ecosystems, with soils serving as critical sinks and active interfaces. As emerging pollutants, MPs can alter soil physicochemical properties and microbial habitats, raising concerns about their effects on microbial functional genes that regulate key biogeochemical processes. This review synthesizes recent progress in understanding how MPs influence soil microbial functional genes and their ecological consequences. MPs modify soil structure, enzyme activity, and microbial community composition, leading to shifts in the diversity and expression of genes related to nutrient cycling and antibiotic resistance. Such changes disrupt microbial-mediated carbon and nitrogen transformations and consequently affect soil ecosystem functioning. The plastisphere and soil fauna gut microbiomes have been identified as hotspots for microbial activity and gene exchange, enhancing the redistribution of functional genes within soil environments. Moreover, environmental factors such as warming, drought, and elevated CO2 interact with MPs, further amplifying or modifying these impacts under global change conditions. Finally, this review highlights the importance of integrating multi-omics, computational, and imaging approaches to deepen understanding of microplastic-microbe interactions, and their implications for soil biogeochemical processes and ecosystem functioning.