POLYCYCLIC AROMATIC COMPOUNDS, cilt.43, sa.8, ss.6819-6836, 2023 (SCI-Expanded)
The present study examined the naphthalene stress responses of the aquatic fern Azolla filiculoides Lam. and evaluated its phytoremediation potential. A. filiculoides were grown in nitrogen (N)-free Hoagland containing 25, 50, and 75 mg L-1 naphthalene in the greenhouse. At 75 mgL(-1) naphthalene concentration, the percentage of plant growth and relative growth rates were 118% and 0,09 gg(-1)d(-1) respectively. Photosynthetic pigment contents increased in parallel with the increasing naphthalene concentrations on the third day. In 75 mg L-1 naphthalene, the flavonoid and phenolic contents of the plant increased as secondary metabolites compared to the control. Gas Chromatography-Mass Spectrometry analysis showed that naphthalene is absorbed, accumulated and/or biodegraded by the A. filiculoides. Percentages of biodegradation from planted samples treated with all naphthalene concentrations on day 10 were >= 94% compared to unplanted controls. Data on growth parameters, photosynthetic pigments and secondary metabolite contents, and biodegradation percentages indicated that the effective phytoremediation potential of A. filiculoides for naphthalene was <= 75 mg L-1. In conclusion, the biodegradation values of over 90% obtained in a short time from the planted samples compared to the unplanted controls showed that A. filiculoides tolerates naphthalene stress highly, is effective in its phytoremediation and can be used efficiently.