Phytotoxicity of BDE-28, BDE-47 and BDE-99 to maize (Zea mays L.) during germination and early growth.

• Phytotoxicity of BDE-28, BDE-47 and BDE-99 to maize (Zea mays L.) during germination and early growth was studied. • PBDEs inhibited seed germination, root and shoot elongation and seedling biomass of maize in a dose-dependent manner. • PBDEs induced overproduction of ROS, which led to lipid peroxidation and DNA damage in maize roots. • BDE-99 caused more severe damage and ROS generation in maize roots than BDE-28 and BDE-47. Although research on the toxic effects of polybrominated diphenyl ethers (PBDEs) on animals has made significant progress, the phytotoxicity of low and medium brominated PBDE congeners to plants has received little attention. A hydroponic experiment was conducted to investigate the toxic effects of 2,4,4′-tribromodiphenyl ether (BDE-28), 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and 2,2′,4,4′,5-pentabromodiphenyl ether (BDE-99) on maize. Seed germination, root and shoot elongation and seedling biomass of maize were inhibited by PBDEs in a dose-dependent manner, and the maximum inhibition rate was achieved at 15 μg L−1. BDE-47 and BDE-99 treatments increased levels of malondialdehyde (MDA) in maize roots in a dose-dependent manner, whereas BDE-28 had no effect on MDA content. The phosphorylated histone H2AX (γ-H2AX) contents in maize roots first increased and then slightly decreased as the exposure concentration of PBDEs increased. These results suggested that PBDEs could induce lipid peroxidation and DNA damage in maize. BDE-28, BDE-47, and BDE-99 exposure increased the production of H 2 O 2 , O 2 •, and •OH, as well as the activity of antioxidant enzymes in the roots. In comparison, BDE-99 caused more severe damage and reactive oxygen species (ROS) generation in maize roots than BDE-28 and BDE-47. These findings show that PBDEs cause oxidative damage to maize and contribute to a better understanding of PBDE safety in terrestrial ecosystems. [ABSTRACT FROM AUTHOR]