赤子爱蚯蚓和菜豆对土壤中硒的归趋的交互作用

发布时间：2024-03-24 08:33

　　硒(Se)是动物必需的微量营养元素,但其营养必需量和致毒剂量之间的差距很小。硒的毒性主要与土壤中无机态的硒有关,即通过植物吸收进入食物链的亚硒酸盐和硒酸盐,对营养水平较高的生物构成了威胁。本实验使用蚯蚓(赤子爱胜蚓)和豆科植物(菜豆)研究了蚯蚓活性对土壤中Se的生物可利用性和随后的植物吸收的影响,二者都在1或4 mg Se kg^-1的亚硒酸盐或硒酸盐中暴露16周。在所有的硒处理中,植物吸收硒酸盐的速度要比吸收亚硒酸盐的速度快(最多可达221倍),并且高达84%的硒会快速转移到芽上。在有蚯蚓存在的条件下,添加了硒酸盐的装置中,植物中硒的含量明显增加,除亚硒酸盐为1 mg kg^-1以外的其他硒处理装置中,硒的转运因子增加了0.85-4.08%。其中,有蚯蚓和硒酸盐存在的装置中,观察到植物组织中硒的积累更快(高达274.38 mg.kg^-1 DW)。为了评估硒对人和其他动物的潜在毒性,我们使用X射线吸收光谱法对暴露于硒的植物和蚯蚓进行了硒形态分析。与无蚯蚓处理的硒酸盐装置相比,在有蚯蚓存在的情况下,豆子中有机硒(即Se Met...

【文章页数】：91 页

【学位级别】：硕士

【文章目录】：
摘要
Abstract
Nomenclature
Chapter 1:Introduction
    1.1 Selenium Overview
        1.1.1 Background
        1.1.2 Selenium deficiency
        1.1.3 Selenium toxicity
        1.1.4 Selenium in Soils
        1.1.5 Selenium uptake in plants
        1.1.6 Selenium metabolism in plants
    1.2 Conventional techniques to remediate contaminated soils
        1.2.1 Physical methods
        1.2.2 Chemical methods
    1.3 Bioremediation technologies
        1.3.1 In-situ bioremediation
        1.3.2 Ex-Situ Bioremediation
    1.4 Phytoremediation
        1.4.1 Phytoextraction
        1.4.2 Phytostabilization
        1.4.3 Phytovolatilization
        1.4.4 Phytodegradation
        1.4.5 Phytofilteration
        1.4.6 Rhizodegradation
    1.5 Role of earthworms in phytoremediation
        1.5.1 Interactions between earthworms and plants
        1.5.2 Interactions between earthworms and heavy metals
        1.5.3 Earthworms and soil enzymes activities
        1.5.4 Interactions between earthworms and soil microorganisms
    1.6 Eco-toxicity of Se
        1.6.1 Eco-toxicity of Se to humans
        1.6.2 Eco-toxicity of Se to animals
    1.7 Research Significance,Content,and Technical Route
        1.7.1 Research significance,purpose,and novelty
        1.7.2 Research content
        1.7.3 Technical route
Chapter 2:Materials and methods
    2.1 Materials
    2.2 Experimental setup
    2.3 Sample Collection
    2.4 Total Se analysis
    2.5 Statistical analysis
    2.6 Se speciation by X-ray absorption spectroscopy(XAS)
Chapter 3:Effect of selenite and selenate on Se accumulation and toxicity in earthworm Eisenia fetida
    3.1 Introduction
    3.2 Experimental
        3.2.1 Materials
        3.2.2 Experimental Setup
        3.2.3 Sample Collection
        3.2.4 Total Se analysis
        3.2.5 Statistical analysis
    3.3 Results
        3.3.1 Se toxicity to earthworms
        3.3.2 Se uptake and excretion by earthworms
    3.4 Discussions
        3.4.1 Earthworm survival and growth and Se uptake
    3.5 Conclusions
Chapter:4 Effect of earthworm Eisenia fetida on Se uptake and growth of bean plant Phaseolus vulgaris L
    4.1 Introduction
    4.2 Experimental
        4.2.1 Materials
        4.2.2 Experimental setup
        4.2.3 Sample collection
        4.2.4 Total Se analysis
        4.2.5 Statistical analysis
    4.3 Results
        4.3.1 Se uptake, accumulation, and translocation in plants
        4.3.2 Effect of earthworm activity and Se on plant growth
        4.3.3 Fate of soil Se
    4.4 Discussions
        4.4.1 Interactions between plants and earthworms
        4.4.2 Effect of earthworm activity on plant growth
        4.4.3 Mass balance of Se
    4.5 Conclusions
Chapter 5:Effect of earthworm Eisenia fetida on Se metabolism in plant Phaseolus vulgaris L.
    5.1 Introduction
    5.2 Experimental
        5.2.1 Materials
        5.2.2 Experimental setup
        5.2.3 Sample collection
        5.2.4 Se speciation by X-ray absorption spectroscopy(XAS)
    5.3 Results
        5.3.1 Biotransformation of Se in plants
        5.3.2 Biotransformation of Se in earthworms
    5.4 Discussions
        5.4.1 Biotransformation of Se in plants
        5.4.2 Biotransformation of Se in earthworms
        5.4.3 Potential eco-risk of Se
    5.5 Conclusions
Chapter 6:Conclusions and recommendations
    6.1 Conclusions
    6.2 Recommendations
References
Acknowledgement
List of Publications



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