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Toxic effects and mechanism of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) on Lemna minor

Author:
Qiu, Nianwei, Wang, Renjun, Sun, Yuan, Wang, Xiushun, Jiang, Dacheng, Meng, Yuting, Zhou, Feng
Source:
Chemosphere 2018 v.193 pp. 711-719
ISSN:
0045-6535
Subject:
Lemna minor, aquatic plants, chlorophyll, fronds, malate dehydrogenase, malondialdehyde, membrane permeability, peroxidase, photosynthesis, plasma membrane, protein content, superoxide anion, thylakoids, toxicity
Abstract:
To investigate the toxic effect and mechanism of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in aquatic plants, in vivo and in vitro exposure to BDE-47 were conducted. After 14-d exposure to 5–20 μg/L BDE-47, the growth of Lemna minor plants was significantly suppressed, and the chlorophyll and soluble protein contents in fronds markedly decreased. Accordingly, the photosynthetic efficiency (Fv/Fm, PI) decreased. When the thylakoid membranes isolated from healthy fronds was exposed to 5–20 mg/L BDE-47 directly in vitro for 1 h, the photosynthetic efficiency also decreased significantly. In both the in vitro (5–20 μg/L) and in vivo (5–20 mg/L) experiments, BDE-47 led to an increased plasma membrane permeability. Hence, we concluded that BDE-47 had a direct toxicity to photosynthetic membranes and plasma membranes. However, direct effects on the activities of peroxidase (POD), malate dehydrogenase (MDH) and nitroreductase (NR) were not observed by adding 5–20 mg/L BDE-47 into crude enzyme extracts. The malondialdehyde (MDA) and superoxide anion radical (O2−) contents in the BDE-47 treated fronds were higher than those in the control fronds, suggesting that L. minor can not effectively relieve reactive oxygen species (ROS). The data above indicates that BDE-47 is toxic to L. minor through acting directly on biomembranes, which induces the production of ROS and thus causes remarkable oxidative damage to cells.
Agid:
5869573