盐生植物碱蓬对镉胁迫的生理响应及其在镉污染土壤修复中的应用

发布时间：2018-01-01 01:23

本文关键词：盐生植物碱蓬对镉胁迫的生理响应及其在镉污染土壤修复中的应用　出处：《南京农业大学》2014年硕士论文　论文类型：学位论文

【摘要】：随着沿海区域经济的高速发展和城市化的加快,近海滩涂的开发利用和陆源污染物排放强度不断增加,导致沿海滩涂土壤污染越来越严重,一些地区滩涂土壤中的Cd等重金属含量己明显超标,而被研究且适用于去除土壤重金属污染的大多数植物修复植物是甜土植物,并不适合于重金属污染滩涂盐土的植物修复。本文以普遍生长于我国沿海滩涂上的碱蓬为研究对象,通过土壤和营养液两种培养方法,研究碱蓬在Cd和NaCl复合处理下的生长、Cd和Na吸收积累特性、抗氧化酶活性、根部亚细胞分布和巯基物质等指标,以期阐明盐生植物碱蓬应答NaCl和Cd双重胁迫的机制、为碱蓬修复重金属Cd污染的滩涂土壤提供理论依据。主要研究内容和结果如下：1.Cd、NaCl合处理下碱蓬对Cd的吸收、转运和生理响应通过水培试验研究了Cd(0、5、10、20 μmol·L-1)和NaCl(0、50、100、200 mmol·L-1)复合处理下,盐生植物碱蓬的生长、Cd的吸收、转运和亚细胞分布、叶绿素、膜脂过氧化作用,抗氧化酶活性以及根部巯基物质含量。结果表明：在Cd和NaCl复合处理后,一定的NaCl浓度处理下,Cd处理浓度的增加将抑制碱蓬的生长,碱蓬植株的含水率随营养介质中盐分的提高而增大,加Cd处理的碱蓬植株鲜重明显低于无Cd处理的碱蓬,碱蓬对Na的富集不受Cd的影响,而NaCl和Cd处理均显著的影响了碱蓬各部位对Cd的吸收累积。碱蓬吸收的Cd主要被累积分配在根部,且大部分被吸附固定在细胞壁上,而富集的Na大部分被转运到地上部,叶茎根部的Na含量均随NaCl处理浓度的增大而显著升高,累积在根部的Na也大部分被吸附固定于细胞壁上。在不加Cd的处理下,碱蓬叶部中的SOD、CAT、TBARS以及叶绿素含量均随NaCl处理的增加而增大,但在加Cd处理后显著地影响了叶部中的SOD、CAT、TBARS以及叶绿素含量。碱蓬根部的NPT和GSH含量均随着盐处理浓度增大而呈上升的趋势,表明根部诱导产生了更多的巯基物质来来缓解根部对Cd的累积的毒害。2.碱蓬修复Cd污染含盐土壤的研究通过温室土壤盆栽试验研究了不同盐(NaCl)浓度(0.1%,0.5%,1.0%)和镉(Cd)浓度(0,1.0,2.5,5.0 mg·kg-1)处理下碱蓬的生长及其对Na和Cd的富集。结果表明,在含0.5%和1.0%NaCl的土壤甲,随着Cd处理浓度的增加,碱蓬的生长显著地受到抑制,生物量均呈减少趋势；随NaCl处理浓度的增加,碱蓬对Cd的积累也随之增加,在0.1%NaCl和2.5 mg·kg-1 Cd的处理土壤中,碱蓬各部位的Cd累计含量达到最大值,叶为30.9 mg·kg-1,茎为30.1 mg·kg-1,根为35.3 mg·kg-1。碱蓬地上部的Cd富集系数为0.9～19.9,地上部吸收的Cd累积量是根部的8.1～73.6倍。NaCl和Cd处理对碱蓬鲜重和根部Cd、Na含量有显著的交互作用,对茎叶部Cd、Na含量的交互作用不显著。在加Cd处理的碱蓬叶和茎部位的Na含量随NaCl处理浓度的增加而增大,但相同NaCl度处理下,Cd处理下的叶茎部Na含量与对照相比差异不显著,且NaCl处理增强了碱蓬对Cd的累积。碱蓬在Cd胁迫下仍保持盐生植物的特性,且对Cd具有较强的耐性和累积能力,有望应用于Cd污染盐土的修复。
[Abstract]:With the rapid development of regional economy in the coastal areas of the city and accelerate the development and utilization of coastal beaches, and terrigenous pollutants emission intensity increased, resulting in coastal soil pollution is becoming more and more serious, the content of heavy metals in some areas of soil in Cd has significantly exceed the standard is applicable to the research, and most of the plants for phytoremediation of heavy metal contaminated soil removal is a glycophyte, is not suitable for phytoremediation of heavy metal pollution in the coastal saline soil. The general growth in China's coastal beach salsa as the research object, through the soil and nutrient solution culture in two, Cd and NaCl in the study of Suaeda salsa under combined treatment of the growth of Cd and Na uptake and accumulation, antioxidant enzyme activity subcellular distribution, root and sulfhydryl compounds and other indicators, to explore the mechanism of Suaeda NaCl response and Cd double stress, heavy metal pollution remediation for Suaeda Cd Provide a theoretical basis for the dyeing of soil. The main research contents and results are as follows: 1.Cd, NaCl and Cd absorption of Suaeda salsa under treatment, was studied through water culture and physiological response of Cd (0,5,10,20 mol transport L-1) and NaCl (0,50100200 mmol L-1) composite treatment, salt plant Suaeda growth. Cd uptake, transport and subcellular distribution, chlorophyll, membrane lipid peroxidation, antioxidant enzyme activity and root thiol content. The results showed that in Cd and NaCl after combined treatment, NaCl concentration is constant, the increase of Cd concentration will inhibit the growth of Suaeda salsa plants, water ratio with salt nutrient medium the increase of Suaeda plants treated with Cd, the fresh weight was significantly lower than that without Cd treatment of Na enrichment on the Suaeda salsa, not influenced by Cd, NaCl and Cd treatments had a significant effect on the absorption of Cd in different parts of Suaeda alkali accumulation. Peng Cd is mainly Absorption Accumulation and distribution in roots, and most of them are adsorbed on the cell wall, and the enrichment of most Na translocated to shoots, leaves and stems are the root of the content of Na increases with the concentration of NaCl increased significantly, accumulate in the roots of Na were mostly solid adsorption on cell wall. In treatment without Cd, Suaeda leaf in SOD, CAT, TBARS and chlorophyll content increased with the increase of NaCl increases, but after treated with Cd significantly affected the leaf in SOD, CAT, TBARS and chlorophyll content. The roots of Suaeda NPT and GSH content were treated with salt increase of concentration was increased, showed that the roots were induced to alleviate the sulfhydryl more roots of Cd toxic.2. salsa Cd contaminated saline soil of greenhouse soil by pot experiment with different salt (NaCl) concentration (0.1%, 0.5%, 1 .0%) and cadmium (Cd) concentration (0,1.0,2.5,5.0 mg kg-1) under the treatment of Suaeda salsa growth and Na and enrichment of Cd. The results showed that in a soil containing 0.5% and 1.0%NaCl, with the increase of Cd concentration, the growth of Suaeda salsa significantly inhibited the biomass decreased with the increase of NaCl; the concentration of Cd, the accumulation of salsa also increased, in the treatment of soil 0.1%NaCl and 2.5 mg kg-1 Cd in different parts of Suaeda Cd accumulated content reached the maximum of 30.9 Mg - kg-1, leaf, stem was 30.1 Mg - kg-1, Mg - kg-1. 35.3 root shoot Cd accumulation coefficient of Suaeda salsa from 0.9 to 19.9, the absorption of Cd accumulation is the root of 8.1 ~ 73.6 times of.NaCl and Cd on the fresh weight of root and Suaeda Cd, there was a significant interaction between Na content of stems and leaves of Cd, the interaction of Na content is not significant. The content of Na plus Cd treatment of Suaeda salsa leaves and stems the site with NaCl concentration The degree of increase, but the same NaCl treatment, leaf stem Na content under Cd treatment compared with the control group had no significant difference, and NaCl treatment enhanced the accumulation of Cd. Suaeda salsa remains characteristic of Halophytes under Cd stress, and the Cd has a strong tolerance and accumulation ability. The repair is expected to be applied to the Cd pollution soil.

【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：X53;X173

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