Evaluation of the phytotoxicity and accumulation potential of nitro-polycyclic aromatic hydrocarbon, 3-nitrofluoranthene, on water status, photosystem II efficiency, antioxidant activity and ROS accumulation in Salvinia natans.

Organic pollutants, which have become one of the most striking problems of today, raise concerns about the spread of polyaromatic hydrocarbon (PAH) compounds into ecosystems and their toxic effects on living organisms. The purpose of this study was to determine how harmful 3-nitrofluoranthene (3-NF) exposure was to Salvinia natans, a freshwater macrophyte. Furthermore, it clarifies how this aquatic plant, which is frequently used in phytoremediation of water contaminants and wastewater treatments, interacts with PAHs and contributes to the development of bioremediation methods. In S. natans exposed to stress (10 μM (3-NF10), 25 μM (3-NF25), 50 μM (3-NF50), 100 μM (3-NF100), 250 μM (3-NF250), 500 μM (3-NF500), 1000 μM (3-NF1000) 3-nitrofluoranthene), 3-NF accumulation, oxidative stress indicators, photosynthetic efficiency, and antioxidant system activity alterations were investigated for this objective. The findings demonstrated that S. natans could effectively accumulate 3-NF, and at a concentration of 1000 μM, the 3-NF content in the leaves reached approximately 1112 mg/kg. While its adverse effects on growth (RGR) and photosynthesis (F/F) remained mild up to a concentration of 250 μM, the severity of the inhibitions increased at higher concentrations. On the other hand, exposure to 3-NF triggered the antioxidant system in S. natans plants and resulted in an increase of 60 %, 80 %, 47 % and 27 % in superoxide dismutase (SOD) activity in 3-NF10-25-50-100 groups, respectively. Conversely, in comparison to control plants, higher concentrations of 3-NF treatments resulted in insufficient antioxidant activity, increased lipid peroxidation (TBARS concentration), and hydrogen peroxide (HO). In conclusion, S. natans plants tolerated 3-NF accumulation up to 250 μM concentration despite limitations in growth suppression and photosynthetic capacity, proving that S. natans has the potential to be used in phytoextraction studies of 3-NF-polluted waters.