biologia plantarum

Biologia plantarum 66:67-75, 2022 | DOI: 10.32615/bp.2021.076

Evaluation of the phytotoxicity of decabromodiphenyl ether (BDE-209) in Chinese cabbage

Y.T. MENG^{1, 2, 3}, Q.Y. ZHAO³, L.Y. WANG³, C. XU³, N.W. QIU³, R.J. WANG^{3, *}, F. ZHOU^{4, *}

¹ State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P.R. China

² University of Chinese Academy of Sciences, Beijing 100049, P.R. China

³ College of Life Sciences, Qufu Normal University, Qufu, Shandong 273165, P.R. China

⁴ School of Food Science, Nanjing Xiaozhuang University, Nanjing 211171, P.R. China

Decabromodiphenyl ether (BDE-209), a major component of brominated flame retardants, has been detected in considerable amounts in the soil. Given that BDE-209 is toxic, ubiquitous, and persistent, it may cause toxic effects on vegetables planted in contaminated soil. In this study, Chinese cabbage seedlings cultivated in the soil contaminated by BDE-209 (5 - 20 mg kg^-1) for 60 d were investigated to evaluate the phytotoxicity of BDE-209 in terms of growth, physiological responses, photosynthetic function, and antioxidant capacity. The results showed that BDE-209-induced phytotoxicity was reflected in the growth suppression, the decrease of chlorophyll content and soluble protein content, and especially in the reduced photosynthetic parameters (net photosynthetic rate and stomatal conductance). BDE-209 showed direct toxicities to plasma membranes causing their elevated permeability. In addition, BDE-209 induced the overproduction of reactive oxygen species (ROS), membrane lipid peroxidation and protein carbonylation, manifesting in the increased content of O₂^*-, H₂O₂, malondialdehyde, and carbonyl. Chinese cabbage seedlings activated the antioxidant defence system (superoxide dismutase and peroxidase) to scavenge the ROS and counter-balance the oxidative stress caused by BDE-209, while the toxicity could not be effectively alleviated. Our study will provide valuable information for further understanding of the phytotoxicity of polybrominated diphenyl ethers.

Keywords: antioxidative enzymes, Brassica rapa, carbonyl, chlorophyll, malondialdehyde, membrane permeability, net photosynthetic rate, ROS, stomatal conductance.

Received: August 31, 2021; Revised: November 2, 2021; Accepted: December 2, 2021; Published online: March 18, 2022  Show citation