宽叶香蒲对重金属的累积与耐性机理研究

发布时间：2018-05-18 04:43

本文选题：多胺 + 重金属　；参考：《中南林业科技大学》2015年硕士论文

【摘要】：重金属污染可引起一系列的环境问题,危害人类的生产生活和健康,因此对重金属污染的防治非常重要。常用的重金属污染治理方法有物理、化学、植物和微生物修复技术。重金属污染的理化治理可能导致土壤的二次污染、微生物治理存在重金属回收难等问题,因此植物修复成为较理想的土壤重金属修复方法。植物修复亦存在周期长,见效慢等缺点,但可以通过提高植物对重金属的耐性和积累来提高其效率。宽叶香蒲可积累多种重金属,多胺具有调控植物生理功能和提高植物对环境胁迫抗性的作用。有关宽叶香蒲对重金属的积累作用和多胺提高植物抗重金属胁迫能力的研究已有报道,但亚精胺(Spermidine, Spd)对镉(Cd)、铅(Pb)单一及复合胁迫下宽叶香蒲对重金属累积、耐性机理的调节研究未见报道。因此,本课题在野外调研凡口铅锌矿人工湿地宽叶香蒲对多种重金属的积累与耐性机理基础上,进一步通过土培实验,采用多功能酶联仪、原子吸收分光光度计等,研究了Cd、Pb单一及其复合胁迫对宽叶香蒲抗氧化系统的影响、宽叶香蒲对Cd、Pb的积累与耐性机理,以及外源Spd对宽叶香蒲吸收积累Cd、Pb、抗氧化系统功能的调控作用。主要结果如下：(1)凡口铅锌矿宽叶香蒲湿地调研：(a)宽叶香蒲是多种重金属的耐性植物,能有效降低人工湿地土壤重金属含量,进水口到出水口土壤重金属的减少量(除Pb、Fe外)均在80%左右。相比单一金属的超富集植物,宽叶香蒲能大量积累多种重金属,符合环境复合污染需求,应用价值更大。(b)宽叶香蒲对重金属的吸收主要受土壤重金属含量的影响,重金属之间的相互作用与根的选择吸收是宽叶香蒲吸收重金属的关键影响因素。(c)宽叶香蒲根系对重金属的大量累积(Cd与Fe在宽叶香蒲地下部的积累均为50%以上,Pb、Zn和Cu都大于80%),尤其是抑制植物非营养元素Cd、Pb向地上部分的转运,叶片细胞壁和胞基质对重金属的阻隔和结合是宽叶香蒲耐受重金属污染的重要机制。(2)宽叶香蒲耐重金属胁迫土培实验：(a) Cd、Pb胁迫明显提高土培宽叶香蒲超氧阴离子自由基(Superoxide anion,O2·-)、过氧化氢(Hydrogen peroxide, H2O2)、丙二醛(Malondialdehyde,MDA)、一氧化氮(Nitric oxide, NO)的积累。外源Spd能够显著提高宽叶香蒲内源Spd的含量,在一定程度上缓解了Cd、Pb对宽叶香蒲的氧化胁迫。相关性分析表明,Cd、Pb胁迫下,外源Spd能够一定程度抑制宽叶香蒲叶片活性氧(Reactive oxygen species, ROS)的产生、脂质过氧化及减弱NO对宽叶香蒲的有害影响,提高宽叶香蒲的对Cd、Pb的抗性。(b) Cd、Pb胁迫能够降低宽叶香蒲叶片可溶性蛋白的含量,但对过氧化物酶(Peroxidase, POD)和过氧化氢酶(Catalase, CAT)影响不大,能够明显提高谷胱甘肽过氧化物酶(Glutathione peroxidase, GPX)的活力,显著降低谷胱甘肽还原酶(Glutathione reductase, GR)的活力,从而影响抗坏血酸-还原型谷胱甘肽(ASA-GSH)系统的功能,导致还原型抗坏血酸(Reduced ascorbate, ASA)和还原型谷胱甘肽(Reduced glutathione, GSH)含量降低。外源Spd能显著提高宽叶香蒲叶片CAT和GR的活力,维持还原性谷胱甘肽/氧化型谷胱甘肽(GSH/GSSG)平衡,使ASA-GSH途径发挥出积极的抗氧化作用。(c) Cd、Pb、Spd处理和宽叶香蒲种植后,土壤的pH值升高,在6.21～6.98内波动,外源Spd可一定程度提高土壤碱度。土壤中Cd、Pb的形态分布与土壤pH值等理化性质相关。Cd、Pb处理浓度和弱酸可溶态含量越高,宽叶香蒲积累重金属越多。总体上,Cd、Pb复合胁迫可促使宽叶香蒲积累更多的重金属,外源Spd可在一定程度上提高植物对Cd、Pb的积累。(d)宽叶香蒲根、茎、叶组织中,Cd、Pb含量的亚细胞分布为细胞壁组分胞基质组分细胞器组分。外源Spd可以通过提高重金属在宽叶香蒲细胞壁或细胞质可溶部分的积累,降低Cd、Pb在细胞器中的含量,提高宽叶香蒲对Cd、Pb的解毒能力。
[Abstract]:Heavy metal pollution can cause a series of environmental problems, endangering human production, life and health, so it is very important for the prevention and control of heavy metal pollution. The commonly used methods of heavy metal pollution control are physical, chemical, plant and microbial remediation. The physical and chemical treatment of heavy metal pollution may lead to two pollution of soil and microbial control. It is difficult to recover heavy metals. Therefore, phytoremediation has become an ideal method for remediation of heavy metals in soil. Plant repair also has some disadvantages, such as long cycle and slow effect. But it can improve the efficiency of plants by improving the tolerance and accumulation of heavy metals. Polyamines can accumulate a variety of heavy metals. Polyamines can regulate plant physiological functions and control plants. The effect of plant resistance to environmental stress was improved. The accumulation of heavy metal and the ability of polyamines to improve plant resistance to heavy metal stress have been reported, but the study of Spermidine (Spd) on the accumulation and tolerance mechanism of heavy metals to cadmium (Cd), lead (Pb) under single and compound stress has not been reported. Therefore, on the basis of the field investigation of the accumulation and tolerance mechanism of the wide leaf cattail in the artificial wetland of vankou lead zinc mine, the effects of Cd, Pb single and its compound coercion on the antioxidant system of the wide leaf cattail were studied by soil culture experiment, and the effects of single and compound coercion on the antioxidant system of the wide leaf cattail were studied. The accumulation and tolerance mechanism of Cd and Pb, and the effect of exogenous Spd on the absorption and accumulation of Cd, Pb, and antioxidant system function of the wide leaf cattail. The main results are as follows: (1) research on the wide leaf cattail wetland in Fankou Lead Zinc Mine: (a) wide leaf cattail is a tolerant plant of heavy metals, which can reduce the content of heavy metals in the soil of the artificial wetland and the water intake to the water. The reduction of heavy metals in the mouth of the mouth (except Pb, Fe) is around 80%. Compared with the single metal hyperconcentration plant, the wide leaf cattail can accumulate a large number of heavy metals, which conforms to the environmental compound pollution demand, and the application value is greater. (b) the heavy metal absorption of the wide leaf cattail to heavy metals is mainly affected by the heavy metal content of soil soil and the interaction between heavy metals and the heavy metals. The selective absorption of roots is a key factor in the absorption of heavy metals in the broad leaf cattail. (c) the accumulation of heavy metals in the root of the wide leaf cattail (Cd and Fe is more than 50% in the lower part of the broad leaf scented cattail, Pb, Zn and Cu are greater than 80%), especially the inhibition of the non nutrient element Cd, the transport of Pb to the upper part of the ground, the cell wall of leaves and the weight of the cell matrix. The barrier and combination of metal is an important mechanism for tolerance to heavy metal pollution of cattail. (2) a Cd, Pb stress obviously improves the superoxide anion radical (Superoxide anion, O2. -), hydrogen peroxide (Hydrogen peroxide, H2O2), malondialdehyde (Malondialdehyde, MDA), nitric oxide. The accumulation of (Nitric oxide, NO). Exogenous Spd could significantly increase the content of endogenous Spd in the wide leaf cattail, to a certain extent alleviated the oxidative stress of Cd and Pb to the wide leaf cattail. The correlation analysis showed that under Cd and Pb stress, exogenous Spd could inhibit the production of active oxygen (Reactive oxygen) and lipid peroxy to a certain extent. The harmful effects of NO on the wide leaf cattail and the resistance to Cd and Pb were improved. (b) Cd, Pb stress could reduce the soluble protein content of the leaves of the wide leaf cattail, but it had little effect on the peroxidase (Peroxidase, POD) and catalase (Catalase, CAT), and could obviously improve the glutathione peroxidase (Glutathione per). The vitality of oxidase, GPX) significantly reduced the activity of glutathione reductase (Glutathione reductase, GR), thus affecting the function of the ascorbic acid and the prototype glutathione (ASA-GSH) system, resulting in reduced content of reduced ascorbic acid (Reduced ascorbate, ASA) and reduced glutathione (Reduced glutathione, GSH). The vitality of high and wide Ye Xiangpu leaves CAT and GR, maintain the balance of reduced glutathione / oxidized glutathione (GSH/GSSG), make ASA-GSH pathway play an active antioxidant effect. (c) Cd, Pb, Spd treatment and wide leaf cattail planting, the soil pH value rises, fluctuates within 6.21 ~ 6.98, exogenous Spd can improve soil alkalinity to a certain extent. Cd in soil, The morphological distribution of Pb was related to the physical and chemical properties of soil pH,.Cd, the higher the concentration of Pb treatment and the soluble content of weak acid, the more heavy metals accumulated in wide Ye Xiangpu. In general, Cd, Pb compound stress could promote the accumulation of more heavy metals in the broad leaf cattail. The exogenous Spd could improve the accumulation of Cd and Pb in plants to a certain extent. (d) broad leaf root, stem and leaf group. The subcellular distribution of the content of Cd and Pb in the fabric is the component of the cellular organelles of the cell wall component. Exogenous Spd can increase the accumulation of heavy metals in the cell wall or the soluble part of the cytoplasm of the wide leaf cattail, reduce the content of Cd, Pb in the organelles, and improve the detoxification ability of the wide leaf cattail to Cd and Pb.
【学位授予单位】：中南林业科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X173;X53

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