Response of cucurbitaceae to perfluoroalkyl and polyfluoroalkyl substances: Effects on photosynthesis and antioxidative enzymes

Perfluoroalkyl and polyfluoroalkyl substances (PFAS), are persistent environmental pollutants with significant implications for plant systems and human health due to their resistance to degradation [1,2]. This study investigated the impact of perfluorooctanoic acid (PFOA) used as a PFAS model compound, on photosynthetic activity and metabolic responses in the Cucurbitaceae family, focusing on Cucumis sativus and Cucurbita pepo. Plants were grown hydroponically under PFOA (0.1 mg/L) to assess physiological and biochemical changes, including photosynthesis efficiency. The greenness of the plants was monitored using a SpectraVue Leaf Spectrometer to determine the Normalized Difference Vegetation Index (NDVI), calculated from a combination of infrared and red bands. Results showed slight reductions in NDVI and alterations in leaf spectral characteristics in treated plants compared to controls, indicating stress-induced modifications in photosynthetic pigments. Enzymatic assays showed significant effects of PFOA and increased superoxide dismutase and catalase activity in plant leaves, stems, and roots. This indicates elevated reactive oxygen species production and oxidative stress, with heightened antioxidant enzyme activity highlighting the resulting redox imbalance. The induced enzyme activity suggests a potential role in PFOA degradation, offering new insights into the plant's detoxification mechanisms. This study underscores the dual impact of PFOA on Cucurbitaceae, compromising photosynthetic efficiency while activating metabolic pathways to mitigate oxidative stress. These findings provide valuable insights into the mechanisms of plant response to PFAS contamination, supporting the development of phytoremediation strategies for PFAS removal.