Integrated transcriptomics and metabolomics analysis reveals molecular mechanisms of submerged macrophytes in response to PFBA and PFHxS

With the banning of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) for persistence and toxicity, the environmental and health risks of their alternatives are highly concerning. This research investigated the response of Vallisneria natans and epiphytic biofilms to perfluorobutanoic acid (PFBA) and perfluorohexane sulfonic acid (PFHxS), alternatives to PFOA and PFOS, respectively, at environmentally relevant concentrations. Exposure to pollutant led to lipid peroxidation, activated antioxidant defenses, and damage cellular structures. The extent of damage was proportional to exposure duration. Moreover, PFBA and PFHxS induce metabolic and transcriptional reprogramming in plants, such as lipid metabolism, membrane transport, phytohormone signal transduction and photosynthesis. Furthermore, we examined the expression of related genes and found that CCD7 , CCD8 , ZEP , NCED , ABA2 and AAO3 were upregulated, promoting the biosynthesis of abscisic acid (ABA) and strigolactones (SL). And ABA activate the MAPK pathway, accompanied by the upregulation of PP2C , SnRK , and mapkkk17_18 , which is a new signal transduction mechanism of plants against PFAS. Additionally, PFAS alternatives exposure affects the structure and function of microbial communities on biofilms. These results offer a more nuanced comprehension of the toxicity of PFBA and PFHxS to aquatic plants, providing information to assess the ecological risk of PFAS alternatives. • Genes involved in photosynthetic pathways and phytohormones biosynthesis were upregulated. • ABA actives the MAPK pathway in plants • PFAS alternatives trigger oxidant stress responses • PFBA and PFHxS exposure changed the microbial community