• 关键词：2,6-二甲基-β-环糊精  EDTA  葎草  Pb污染

• 基金项目：国家自然科学基金（No.31571604）

• 杨丹丹
• 山西师范大学地理科学学院, 临汾 041000

• 杨丽雯
• 1. 山西师范大学地理科学学院, 临汾 041000;2. 山西大学生命学院, 太原 030006

• 张永清
• 山西师范大学地理科学学院, 临汾 041000

• 甄霞
• 山西师范大学地理科学学院, 临汾 041000

• 张滋芳
• 山西师范大学生命科学学院, 临汾 030006

• 王淑琴
• 山西师范大学地理科学学院, 临汾 041000

• 李雅
• 山西师范大学地理科学学院, 临汾 041000

• 摘要：采用盆栽试验研究了EDTA、2，6-二甲基-β-环糊精对Pb污染土壤上葎草生长及Pb积累特性的影响.土壤中硝酸铅含量分别为0、600和1200 mg·kg^-1，螯合剂的含量为硝酸铅含量的0.5倍和1.0倍.结果表明：EDTA和2，6-二甲基-β-环糊精对Pb离子均有显著増溶作用，且二者之间没有差异；EDTA对葎草的生长有轻微抑制作用，而2，6-二甲基-β-环糊精与对照没有差异，原因可能是形成了Pb-2，6-二甲基-β-环糊精络合物降低了Pb的毒性；EDTA和2，6-二甲基-β-环糊精都显著促进了葎草根、茎、叶部对Pb离子的吸收.EDTA处理的葎草在硝酸铅含量为600 mg·kg^-1，螯合剂浓度为0.9 mmol·L^-1时，转移率达到最大值1.34，而2，6-二甲基-β-环糊精的转移率最大值为0.36.虽然2，6-二甲基-β-环糊精的转移率较低，但由于葎草的生物量大，2，6-二甲基-β-环糊精可以作为葎草提取修复的一种新型螯合剂，葎草也可用作植物提取修复的参考植物.由于2，6-二甲基-β-环糊精具有独特的“内疏水，外亲水”结构，推测其促进葎草吸收转移Pb的机理可能是会以Pb-2，6-二甲基-β-环糊精络合物的溶解物形式在葎草的质外体通道中移动，进入木质部，最终通过蒸腾流的驱动转运至地上部.

• Abstract：Pot experiment was performed to study the influences of EDTA and 2, 6-Demethyl-β-Cyclodextrin on the pollutant accumulation and the growth of H.scandens in the Pb polluted soils. In our experiment, soil was spiked with Pb(NO₃)₂ concentrations of 0, 600 and 1200 mg·kg^-1, and chelates (EDTA and DM-β-CD) were prepared at 1:1 and 0.5:1 ratios with the metal. The results revealed that EDTA and DM-β-CD were both efficient in bringing Pb into solution without significant difference. EDTA applications affected H. scandens's growth slightly, while no significant reduction in dry matter production appeared after the DM-β-CD addition. The reason may be that the formation of Pb-DM-β-CD reduced the toxicity of lead. EDTA and DM-β-CD both significantly increased Pb concentration in roots, stems and leaves of H. scandens. The translocation factor (TF) value reached maximum (1.34) when soil Pb(NO₃)₂ concentration was 600 mg·kg^-1 and EDTA at 0.9 mmol·L^-1; while that of DM-β-CD application was 0.36. Although the TF rate of DM-β-CD was less than that of EDTA, we could still use DM-β-CD for phytoextraction purposes because of the high biomass of H. scandens. The results showed that highly biodegradable and non-toxic DM-β-CD can be a good chelant to enhance the phytoextraction of Pb. DM-β-CD has special molecular cavity structure of exo-hydrophilicity and endo-hydrophobicity. The mechanism of DM-β-CD enhancing the phytoextraction of Pb is that the solubilized Pb-DM-β-CD complex is transported through the apoplast channel of H. scandens, into the xylem, and finally via transpiration steam accumulates in the overground parts.

• Key words：2, 6-Demethyl-β-Cyclodextrin  EDTA  Humulus scandens (Lour.) Merr.  lead pollution

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