重金属铅胁迫下EDTA对狗牙根抗氧化酶及土壤磷、铅形态的影响  

Effects of EDTA on Antioxidant Enzymes of Cynodon dactylon and Forms of Phosphorus and Lead in Soil under Lead Stress

作　　者：姜冉冉 江润海 朱城强 侯秀丽 Jiang Ranran;Jiang Runhai;Zhu Chengqiang;Hou Xiuli(School of Agriculture and Life Sciences,Kunming University,Kunming 650214,China)

机构地区：[1]昆明学院农学与生命科学学院,云南昆明650214

出　　处：《山东农业科学》2023年第4期131-138,共8页Shandong Agricultural Sciences

基　　金：国家自然科学基金地区基金项目(42167009);云南省高校联合基金项目(2018FH001-004);昆明学院农业资源利用科技创新团队项目。

摘　　要：为探究施用乙二胺四乙酸(EDTA)增强狗牙根(Cynodon dactylon)修复重金属铅污染土壤的效果,本研究采用盆栽试验,设置0(CK)、2.5、5、7.5、10 mmol/L共5个EDTA浓度处理,研究重金属铅胁迫下施用EDTA对狗牙根抗氧化酶系统及土壤不同形态磷、铅含量的影响。结果表明:10 mmol/L EDTA处理下狗牙根根部的过氧化物酶(POD)活性、丙二醛(MDA)含量均显著高于对照,分别是对照的1.63、1.95倍,过氧化氢酶(CAT)活性与对照无显著差异但显著高于其它浓度处理;狗牙根根际、非根际土壤Ca-P含量较对照显著降低39.42%、51.24%,而根际土壤Fe-P含量是对照的1.92倍;狗牙根地上部和根部Pb富集量最高,分别是对照的8.84倍和1.91倍,且转移系数大于1;根际土壤中有效态铅含量最高,为92.83 mg/kg,是对照的1.84倍。以上结果表明施用10 mmol/L的EDTA能够有效促进根际土壤中铁锰氧化态铅、腐殖酸结合态铅、残渣态铅和强有机结合态铅转化为有效态铅,提高狗牙根对铅的吸收,增强POD、CAT的氧化应激反应,提高狗牙根在高浓度铅胁迫下的耐受能力。To investigate the effect of chelating agent ethylenediaminetetraacetic acid(EDTA)on strengthening the remediation of heavy metal lead contaminated soil by Cynodon dactylon,this study used a pot experiment,with 5 EDTA concentrations of 0(CK),2.5,5,7.5 mmol/L and 10 mmol/L to study the effects of EDTA application on the antioxidant enzyme system of Cynodon dactylon under heavy metal lead stress and the content of different forms of phosphorus and lead in the soil.The results showed that under 10 mmol/L EDTA treatment,the peroxidase(POD)activity and malondialdehyde(MDA)content in the roots of Cynodon dactylon were significantly higher than those of CK,and were 1.63 and 1.95 times of CK,respectively;the catalase(CAT)activity was not significantly different from that of CK,but significantly higher than that under other concentration treatments.The Ca-P content in the rhizosphere and non-rhizosphere soil of Cynodon dactylon was significantly reduced by 39.42%and 51.24%respectivelly compared with CK,while the Fe-P content in the rhizosphere soil was 1.92 times of that of the control.The lead enrichment levels in the aboveground and root parts of Cynodon dactylon were the highest,which were 8.84 and 1.91 times of those of the control,respectively,and the transfer coefficient was greater than 1.The available lead content in the rhizosphere soil was the highest as 92.83 mg/kg,which was 1.84 times of control.The above results indicated that the application of 10 mmol/L EDTA could effectively promote the transformation of iron manganese oxide bound lead,humic acid bound lead,residual lead and strongly organic bound lead into effective lead in rhizosphere soil,increase the absorption of lead in aerial parts and roots of Cynodon dactylon,enhance the oxidative stress response of POD and CAT,and improve the tolerance of Cynodon dactylon under high concentration of lead stress.

关 键 词：狗牙根 乙二胺四乙酸(EDTA) 抗氧化酶系统 植物铅富集 土壤磷、铅形态 

分 类 号：S158.4[农业科学—土壤学] X53[农业科学—农业基础科学]