PFOS-induced alterations in phosphorus dynamics and soil microbial functions in wetlands

Perfluorooctanesulfonate (PFOS), a widely persistent pollutant, poses significant ecological risks, yet its impact on critical nutrient cycles, such as phosphorus (P), in wetland ecosystems remains poorly understood. Phosphorus is essential for plant growth and microbial functions, and disruptions in its cycling can have profound effects on ecosystem stability. This study investigates the influence of PFOS on P dynamics and soil microbial functions in the rhizosphere of Phragmites communis. We examined how varying PFOS concentrations affect inorganic and organic P forms and microbial gene expression associated with P transformations. High PFOS concentrations significantly reduced shoot and root P content, corresponding to declines in labile phosphorus (NaHCO₃-Pi). Additionally, shifts in microbial community diversity and composition were observed, particularly under high PFOS exposure, where key phosphorus-cycling genes, such as phoD in rhizosphere soils, showed significantly reduced transcriptional levels (as quantified by qRT-PCR), despite increased gene abundance as revealed by metagenomic sequencing. These findings offer new insights into how emerging contaminants like PFOS disrupt phosphorus cycling and microbial functions in wetland ecosystems, with broader implications for ecological risk assessments.