This study aims to explore the effects of arbuscular mycorrhizal fungi (AMF) on the growth of Iris pseudacorus L. and treatment efficacy in constructed wetlands (CWs) subjected to stress from per-and poly-fluoroalkyl substances (PFASs). The findings reveal that PFASs exposure induces oxidative damage and inhibits the growth of I . pseudacorus. However, AMF symbiosis enhances plant tolerance to PFAS stress by modulating oxidative responses. AMF treatment not only promoted plant growth but also improved photosynthetic efficiency under PFAS exposure. Compared to non-AMF treatment, those with AMF treatment exhibited significantly increased levels of peroxidases and antioxidant enzymes, including peroxidase and superoxide dismutase, along with a notable reduction in lipid peroxidation. Additionally, AM symbiosis markedly enhanced the efficacy of CWs in the remediation of wastewater under PFASs-induced stress, with removal efficiencies for COD, TP, TN, and NH4+- N increasing by 19-34%, 67-180%, 106-137%, and 25-95%, respectively, compared to the AMF- treatments. In addition, the metabolic pathways of PFASs appeared to be influenced by their carbon chain length, with long- chain PFASs like perfluorooctanoic acid (PFOA) and perfluoro anionic acid (PFNA) exhibiting more complex pathways compared to short-chain PFASs such as perfluoro acetic acid (PFPeA), and perfluoro hexanoic acid (PFHpA). These results suggest that AMF-plant symbiosis can enhance plant resilience against PFAS-induced stress and improve the pollutant removal efficiency of CWs. This study highlights the significant potential of AMF in enhancing environmental remediation strategies, providing new insights for the more effective management of PFAS-contaminated ecosystems.

Constructed wetlands (CWs) have been widely used for treating polluted water since the 1950s, with applications in over 50 countries worldwide. Most studies investigating the pollutant removal efficiency of these wetlands have focused on differences among wetland designs, operation strategies, and environmental conditions. However, there still remains a gap in understanding the variation in wetland pollutant removal efficiency over different time scales. Therefore, the main aim of the study is to address this gap by conducting a global metaanalysis to estimate the variation in nitrogen (N) and phosphorus (P) removal by wetland in short- and longterm pollutant treatment. The findings of this study indicated that the total efficiencies of N and P removal increased during short-term wetland operation but decreased during long-term operation. However, for surface flow CWs specifically, the efficiencies of N and P removal increased during short-term operation and remained stable during long-term operation. Moreover, the study discovered that wetland N removal efficiency was influenced by seasons, with an increase in spring and summer and a decrease in autumn and winter. Conversely, there was no significant seasonal effect on P removal efficiency. Additionally, high hydraulic load impaired wetland N and P removal efficiency during long-term operation. This study offers a critical review of the role of wetlands in wastewater treatment and provides valuable reference data for the design and selection of CWs types during wastewater treatment in the aspect of sustainability.