Abstract Polybrominated diphenyl ethers (PBDEs) have been highly concerned as environmental organic pollutants. 4-Bromodiphenyl ether (BDE-3) is one of the lowest brominated diphenyl ethers used as a representative of monobromobiphenyl ethers for exploring the environmental behavior and toxicology of PBDEs. The root differentiation is the critical response to the exposure of persistent organic pollutants (POPs) for understanding the phytoremediation mechanism. In this article, the adventitious root differentiation of tissue cultural seedlings of Triarrhena sacchariflora was observed under BDE-3 exposure conditions. The results showed that 3.0 mg·L−1 BDE-3 had significant positive effects on the adventitious root differentiation and the biomass, in which the higher dosage of 30.0 mg·L−1 showed inhibition effects and symptoms of injury of seedlings. The endogenous IAA/ZR ratio was at higher level than the controls and coincident with the adventitious roots differentiation in the same treatment of 3.0 mg·L−1 BDE-3. However, the responses of coleoptile elongation of Zea mays and the DR5::GUS reporter gene of Arabidopsis thaliana to BDE-3 exposure were all negative comparing with the positive controls. It could be inferred from the results that the BDE-3 may not be an auxin-like substance, and its hormesis on the adventitious root differentiation of T. sacchariflora might result from changes of endogenous IAA/ZR due to the action of BDE-3. In our knowledge, it was the first report concerning the BDE-3 hormesis on the adventitious root differentiation of T. sacchariflora tissue culture seedlings. The findings are meaningful to the further understanding of the BDE-3 effects on the plant endogenous signal substances that regulate the plant growth and development which are closely related to the phytoremediation of POPs.

中文翻译：

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4-溴二苯醚对三花粉菌组培苗不定根分化的影响

摘要 多溴联苯醚（PBDEs）作为一种环境有机污染物一直备受关注。4-溴二苯醚 (BDE-3) 是溴化程度最低的二苯醚之一，用作探索多溴二苯醚的环境行为和毒理学的单溴联苯醚的代表。根系分化是对持久性有机污染物 (POPs) 暴露的关键反应，以了解植物修复机制。本文观察了BDE-3暴露条件下糖花木薯组培苗的不定根分化。结果表明，3.0 mg·L-1 BDE-3对不定根分化和生物量具有显着的正向影响，其中30.0 mg·L-1的较高剂量显示出抑制作用和幼苗损伤症状。内源IAA/ZR比值高于对照，与3.0 mg·L-1 BDE-3相同处理下的不定根分化一致。然而，与阳性对照相比，玉米胚芽鞘伸长和拟南芥的 DR5::GUS 报告基因对 BDE-3 暴露的反应均为阴性。由结果可知，BDE-3可能不是生长素类物质，其对T. sacchariflora不定根分化的刺激作用可能是由于BDE-3作用引起的内源IAA/ZR的变化。 . 据我们所知，这是关于 BDE-3 对 T. sacchariflora 组培苗不定根分化的刺激作用的首次报道。