摘要
研究可生物降解螯合剂N-十二酰基乙二胺三乙酸盐(LED3A)诱导强化紫花苜蓿修复Cd污染土壤的效果,采用盆栽方法,考察LED3A对紫花苜蓿生理指标、Cd亚细胞分布和化学形态以及增效提取土壤中Cd的影响.结果表明,Cd胁迫显著抑制紫花苜蓿的生长及光合作用,增加丙二醛(MDA)的积累.而在土培体系中施用LED3A,可以提高植株生物量、光合色素含量、过氧化物酶(POD)和超氧化物歧化酶(SOD)活性,缓解细胞膜脂过氧化损伤和Cd诱导产生的氧化应激.LED3A的螯合强化作用能够增大紫花苜蓿细胞质中Cd的分布比例,促使植株中的Cd由高活性形态向低活性形态转化,通过细胞壁固持和液泡区隔化提高耐Cd性能,进而减轻毒害.与不添加LED3A组相比,最佳LED3A添加量(321.3 mg·kg^(-1))组紫花苜蓿植株中的总Cd含量和积累量分别提高了29.4%和69.1%,地下/地上富集系数及转运系数分别增加了28.6%,36.4%和10.5%.说明添加适量LED3A可有效提高紫花苜蓿对Cd的耐受性与修复Cd污染土壤的效果.
A biodegradable chelating agent named N-lauroyl ethylenediamine triacetate(LED3A)was applied to the induction-enhanced phytoremediation of Cd contaminated soil by alfalfa.The pot experiments were conducted to investigate the effect of LED3A on the physiological indexes of alfalfa,the variations in subcellular distribution and chemical forms of Cd in plants,as well as the performance of LED3A in assisting phytoextraction of Cd from soil.The results showed that Cd stress significantly inhibits the plant growth and photosynthesis,and increases malondialdehyde(MDA)accumulation.After application of LED3A into soil-cultivated system,the biomass,photosynthetic pigments content,peroxidase(POD)and superoxide dismutase(SOD)activities of alfalfa all increase.Changes in these indexes can alleviate cellular membrane lipid peroxidation damage and oxidative stress caused by Cd.LED3A s chelating enhancement effect results in a higher proportion of Cd in the cytoplasm of alfalfa cells,facilitates the transformation of Cd from highly active forms to less active forms within the plant,improves Cd resistance and reduces toxicity through cell wall immobilization and vacuole compartmentalization.Compared with the treatment without LED3A,the total Cd content and accumulation in alfalfa at optimal LED3A dosage(321.3 mg·kg^(-1))are increased by 29.4%and 69.1%.The bioconcentration factor(BCF)and translocation factor(TF)of Cd in alfalfa root and shoot increase correspondingly by 28.6%,36.4%and 10.5%,respectively.In conclusion,the application of situable amount of LED3A can improve the Cd tolerance of alfalfa and enhance the efficiency of phytoremediation for Cd contaminated soil.
作者
刁静茹
肖奇赞
张淋淋
闫利甜
赵保卫
DIAO Jing-ru;XIAO Qi-zan;ZHANG Lin-lin;YAN Li-tian;ZHAO Bao-wei(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,Gansu,China)
出处
《西北师范大学学报（自然科学版）》
2024年第1期61-69,共9页
Journal of Northwest Normal University(Natural Science)
基金
国家自然科学基金资助项目(41261077)
甘肃省高等学校创新基金项目(2021B-102)。
