title: Accumulation and phytotoxicity of technical hexabromocyclododecane in maize.
abstract: To investigate the accumulation and phytotoxicity of technical hexabromocyclododecane (HBCD) in maize, young seedlings were exposed to solutions of technical HBCD at different concentrations. The uptake kinetics showed that the HBCD concentration reached an apparent equilibrium within 96hr, and the accumulation was much higher in roots than in shoots. HBCD accumulation in maize had a positive linear correlation with the exposure concentration. The accumulation of different diastereoisomers followed the order γ-HBCD>β-HBCD>α-HBCD. Compared with their proportions in the technical HBCD exposure solution, the diastereoisomer contribution increased for β-HBCD and decreased for γ-HBCD in both maize roots and shoots with exposure time, whereas the contribution of α-HBCD increased in roots and decreased in shoots throughout the experimental period. These results suggest the diastereomer-specific accumulation and translocation of HBCD in maize. Inhibitory effects of HBCD on the early development of maize followed the order of germination rate>root biomass≥root elongation>shoot biomass≥shoot elongation. Hydroxyl radical (OH) and histone H2AX phosphorylation (γ-H2AX) were induced in maize by HBCD exposure, indicative of the generation of oxidative stress and DNA double-strand breaks in maize. An OH scavenger inhibited the expression of γ-H2AX foci in both maize roots and shoots, which suggests the involvement of OH generation in the HBCD-induced DNA damage. The results of this study will offer useful information for a more comprehensive assessment of the environmental behavior and toxicity of technical HBCD.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; School of Environmental Science and Engineering, Hebei University of Science and Technology, Hebei 050018, China. Electronic address: wutong1982819@163.com.
authors.forename: Tong
authors.initials: T
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Honglin
authors.initials: H
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: szzhang@rcees.ac.cn.
authors.forename: Shuzhen
authors.initials: S
authors.lastname: Zhang
mesh_terms: D006842:Hydrocarbons, Brominated / Q000378:metabolism / Q000633:toxicity*; D017665:Hydroxyl Radical; D018384:Oxidative Stress; D012989:Soil Pollutants / Q000378:metabolism / Q000633:toxicity*; D003313:Zea mays / Q000187:drug effects* / Q000378:metabolism
chemical_list: D006842:Hydrocarbons, Brominated; D012989:Soil Pollutants; D017665:Hydroxyl Radical; C089796:hexabromocyclododecane
keywords: DNA damage; Oxidative toxicity; Plant uptake; Technical hexabromocyclododecane (HBCD)