Phytotoxicity and plant uptake of decabromodiphenyl ethane under citric acid

Abstract The novel brominated flame retardant decabromodiphenylethane (DBDPE) has biological toxicity, persistence, long-range migration and bioaccumulation ability. However, there is currently a lack of research on the phytotoxicity of DBDPE to herbaceous plants. Therefore, this study selected the perennial herbaceous plant tall fescue as the model material and conducted outdoor seed germination experiments using soil contamination method to study the toxic effects of DBDPE on tall fescue seedlings. The results indicated that DBDPE significantly inhibited the germination of tall fescue seeds, and it had significant impact on the physiological and biochemical indicators and antioxidant enzyme activity of tall fescue seedlings. Citric acid could effectively alleviate the toxicity of DBDPE to tall fescue, and seedlings improved their tolerance to DBDPE stress by regulating the content of proline, soluble protein, and soluble sugar in cells. Compared with the control, there was no significant difference in superoxide dismutase (SOD) and peroxidase (POD) activities in tall fescue seedlings, but catalase (CAT) activity and malondialdehyde (MDA) content were significantly increased. Tall fescue seedlings had certain bioaccumulation effect for DBDPE, with biological concentration factor (BCF) ranging from 4.28 to 18.38 and transfer factor (TF) ranging from 0.43 to 0.54, and DBDPE was mainly bio accumulated in the roots of tall fescue seedlings. The citric acid significantly promoted the bio concentration capacity of tall fescue seedlings for DBDPE. It provides theoretical support for the toxicity study of DBDPE on plants, and it provides certain research foundation for exploring the phytoremediation of DBDPE contaminated soil by tall fescue.