摘要
为了揭示多氯联苯Aroclor1242对荻组培苗不定根分化影响的作用机制,以多氯联苯Aroclor1242为污染物,对处于分化和生长过程中的荻组培苗不定根全程持续暴露,研究Aroclor1242对荻组培苗不定根分化的影响,并利用玉米胚芽鞘伸长试验和拟南芥 DR5::GUS 报告基因应答反应定性分析Aroclor1242的类植物生长素生物效应。结果表明:2 mg/L、4 mg/L、6 mg/L和8 mg/L Aroclor1242暴露对荻不定根分化具有显著的促进作用,其不定根初根时间、不定根分化率达到100%时间以及侧根等均显著高于阴性对照,8 mg/L Aroclor1242对荻不定根分化促进作用最大,其初根时间比阴性对照提前9 d,比阳性对照提前2 d,不定根分化率达100%时间比阴性对照提前9 d,比阳性对照提前5 d;10 mg/L和20 mg/L Aroclor1242暴露对荻不定根分化表现出抑制作用。物质的类植物生长素定性分析发现,一定剂量的Aroclor1242对玉米胚芽鞘伸长无显著影响,但可以诱导生长素响应报告基因( DR5::GUS )阳性应答。以上结果表明,低剂量Aroclor1242可显著促进荻不定根分化而高剂量抑制,存在显著的剂量效应关系。Aroclor1242可能不是类植物生长素,但可能会通过影响植物内源生长素水平影响荻不定根分化。该发现为进一步深入研究PCBs不同同系物的毒理学及其植物修复机制提供了新的线索。
Using tissue culture seedlings of Triarrhena sacchariflora, Zea mays and Arabidopsis thaliana as test materials, the effects of Aroclor1242 on the adventitious root differentiation and the mechanism were analyzed using the Aroclor1242 whole exposure system,coleoptile elongation experiment of Zea mays and the response of DR5::GUS reporter gene. The results showed: 2 mg/L, 4 mg/L, 6 mg/L and 8 mg/L Aroclor1242 had significant promotion effects on adventitious root differentiation, and their the initial rooting time, the time of adventitious root differentiation rate reaching 100%, and lateral roots were all significantly higher than that of negative control. 8 mg/L Aroclor1242 had the greatest effect on adventitious root differentiation. The initial rooting time of the 8 mg/L Aroclor1242-treated tissue culture seedlings was 9 days earlier than the negative control and 2 days earlier than the positive control. The time of adventitious root differentiation rate reaching 100% was 9 days earlier than the negative control and 5 days earlier than the positive control. 10 mg/L and 20 mg/L Aroclor1242 showed inhibition effect. Qualitative analysis of auxin-like substances found that a certain dose of Aroclor1242 had no significant effect on the responses of coleoptile elongation of Zea mays , but induced positive response of auxin DR5::GUS reporter. The above results indicate that low dose of Aroclor1242 can significantly promote adventitious root differentiation while high dose has the inhibition effect, and there is a significant dose-effect relationship. Aroclor1242 may not be an auxin-like substance and its hormesis on the adventitious root differentiation of T. sacchariflora might result from changes of endogenous auxin. This discovery provides new clues for further research into the toxicology and phytoremediation mechanisms of different homologues of PCBs.
作者
王亚校
王子岚
孙然
杜克久
WANG Yaxiao;WANG Zilan;SUN Ran;DU Kejiu(College of Forestry, Hebei Agricultural University,Baoding 071000,China;Key Laboratory of Tree Species Germplasm Resourse and Forest Protection of Hebei Province,Hebei Agricultural University,Baoding 071000,China)
出处
《林业与生态科学》
2019年第3期308-313,共6页
Forestry and Ecological Sciences
基金
河北省自然科学基金(C2018204134)
“十二五”农村领域国家科技计划(No.2012AA101403)
环境化学与生态毒理学国家重点实验室开放基金(No.KF2009-03)
关键词
多氯联苯
Aroclor1242
荻
不定根
polychlorinated biphenyls (PCBs)
Aroclor1242
Triarrhena sacchariflora
adventitious roots
