镉胁迫下硒对蚓体镉富集、亚细胞分布和抗氧化指标的影响  

Effect of Selenium on Cadmium Bioaccumulation,Subcellular Distribution,and Antioxidant Indexes in Earthworms Under Cadmium Stress

作　　者：杨慕源 周升志 杨莹 姜珊 周子涵 符晓雯 王瑞萍 岳士忠 YANG Muyuan;ZHOU Shengzhi;YANG Ying;JIANG Shan;ZHOU Zihan;FU Xiaowen;WANG Ruiping;YUE Shizhong(Shandong Key Laboratory of Biophysics,Institute of Biophysics,Dezhou University,Dezhou 253023,China;Belgorod College of Food Sciences,Dezhou University,Dezhou 253023,China;College of Life Sciences,Dezhou University,Dezhou 253023,China)

机构地区：[1]山东省生物物理重点实验室,德州学院生物物理研究院,德州253023 [2]德州学院别尔哥罗德食品科学学院,德州253023 [3]德州学院生命科学学院,德州253023

出　　处：《生态毒理学报》2025年第1期383-396,共14页Asian Journal of Ecotoxicology

基　　金：国家自然科学基金项目(32301418);山东省高等学校大学生创新创业训练计划项目(S202310448127,X202410448066);德州学院人才引进项目(2019XJRC328)。

摘　　要：为了解硒(Se)对重金属镉(Cd)污染土壤中蚯蚓所受胁迫的调节作用与机制,本研究以赤子爱胜蚓(Eisenia foetida)为研究对象,通过在Cd污染人工土壤中(150 mg·kg^(-1)和300 mg·kg^(-1))添加外源Se(5 mg·kg^(-1)和10 mg·kg^(-1))探究7 d和14 d其对蚯蚓生长、蚓体Cd累积与亚细胞分布和抗氧化指标的影响。结果表明:Cd能抑制蚯蚓生长且呈剂量-效应,Se在一定程度上缓解了Cd胁迫对生物量的抑制。7 d时Se有效抑制了暴露于污染土壤中的蚓体Cd累积和富集系数(BAF_(Cd)),而14 d时无显著影响,说明Se抑制蚓体Cd富集受暴露时间影响较大,短时间内抑制作用较好,且短时间共同暴露条件下Se能减弱蚯蚓对Cd的富集能力;基质Cd浓度对蚯蚓Se富集有抑制作用,且浓度越大抑制作用越强。Cd在蚯蚓亚细胞中的分布为细胞溶质S1>细胞碎片S2>固体颗粒S3,且Cd在不同亚细胞中的比例随土壤Cd、Se浓度和暴露时间延长而有所差异;14 d时,高Cd基质添加Se处理组蚓体S1中Cd占比均在85%以上,较7 d时有所增加,说明14 d暴露可能促进了Se对Cd的解毒。此外,适量Se(5 mg·kg^(-1))添加提高了蚯蚓超氧化物歧化酶和过氧化氢酶活性、促进了谷胱甘肽合成、抑制了丙二醛产生,有助于提高Cd污染胁迫下蚯蚓的抗氧化免疫。综上,Se通过促进Cd在蚯蚓细胞溶质中的分布解毒和增强抗氧化防御降低了蚯蚓所受污染胁迫压力,本研究为缓解土壤生物所受污染胁迫提供了新的研究思路与方法。This study was conducted to investigate the regulatory effects and mechanisms of selenium(Se)on earthworm stress induced by cadmium(Cd)-contaminated soil.Exogenous Se(5 mg·kg^(-1)and 10 mg·kg^(-1))was added to artificial soil contaminated with Cd(150 mg·kg^(-1)and 300 mg·kg^(-1))to assess its impact on the growth,Cd accumulation,subcellular distribution,and antioxidant responses of Eisenia fetida over 7 d and 14 d.The results showed that Cd inhibited the earthworm growth in a dose-effect manner,while Se alleviated Cd-induced biomass reduction.Se effectively reduced Cd accumulation and the bioaccumulation factor(BAF_(Cd))in earthworm tissues at day 7,but this effect diminished by day 14,suggesting that the efficiency of Se inhibition was influenced by exposure duration.Se also inhibited Cd bioaccumulation in earthworms,with the inhibitory effect increasing with higher soil Cd concentrations.Subcellular distribution of Cd was predominantly in the cytosol(S1)>cell debris(S2)>granules(S3),and the proportions of Cd in these fractions varied with soil Cd concentration,Se treatment,and exposure duration.At day 14,more than 85%of the Cd in the high-Cd soil with Se was localized in the cytosol,higher than at day 7,indicating that prolonged exposure may enhance Se-mediated detoxification of Cd.Furthermore,Se(5 mg·kg^(-1))increased the activities of superoxide dismutase(SOD)and catalase(CAT),promoted glutathione(GSH)synthesis,and inhibited malondialdehyde(MDA)production,thereby enhancing the antioxidant defenses of earthworms under Cd stress.In conclusion,Se mitigates the detrimental effects of Cd on earthworms by promoting Cd detoxification in the cytosol and bolstering antioxidant defenses.This study offers novel insights and methodologies for alleviating pollution stress in soil organisms.

关 键 词：镉胁迫 硒 蚯蚓 亚细胞分布 抗氧化 

分 类 号：X171.5[环境科学与工程—环境科学]