铅锌尾矿污染区3种菊科植物体内重金属的亚细胞分布和化学形态特征

发布时间：2018-03-28 01:28

本文选题：重金属污染　切入点：铅锌尾矿　出处：《环境科学》2017年07期

【摘要】：通过实地调查分析广西阳朔某铅锌尾矿污染农田自然生长的3种常见菊科植物野艾蒿、胜红蓟和野茼蒿体内的重金属含量,并采用差速离心与化学试剂提取法分析重金属在植物中的亚细胞分布及其存在的化学形态,探究菊科植物对重金属的积累、耐性特征和机制.结果表明,污染区土壤受Cd、Pb、Zn这3种重金属污染严重,其含量分别比国家土壤环境二级标准(GB 15618-1995)超标37.7、5.7和8.9倍,植物体内Cd、Pb和Zn含量都超过正常范围.野茼蒿和胜红蓟对Cd具有较强的迁移能力和富集能力,适用于Cd污染土壤的生态修复.此外,野茼蒿的茎和叶中Cd的含量分别为159.6 mg·kg~(-1)和219.5mg·kg~(-1),超过Cd超富集植物的临界标准,可见野茼蒿完全具有Cd超富集植物的基本特征,是Cd超富集植物.3种菊科植物地下部和地上部的Cd、Pb和Zn主要分布在液泡可溶组分和细胞壁中,而在细胞器中的分布较少.植株中大部分的重金属以迁移性较低的氯化钠提取态、醋酸提取态和盐酸提取态存在.因此,液泡区隔化、细胞壁固持和重金属以低活性的化学形态为主可能是3种菊科植物应对重金属胁迫的重要耐性机制.与野艾蒿相比,胜红蓟和野茼蒿茎叶中的Cd更多地贮存在液泡中,且地上部"活性态"Cd的积累比例低于根系,这些很可能是胜红蓟和野茼蒿忍耐和富集镉的重要途径.
[Abstract]:The heavy metal contents of Artemisia annua, Artemisia japonicum and Chrysanthemum chrysanthemum, three common plants of Compositae, which were polluted by lead and zinc tailings in Yangshuo, Guangxi, were investigated. The subcellular distribution and chemical forms of heavy metals in plants were analyzed by differential centrifugation and chemical reagent extraction, and the accumulation, tolerance and mechanism of heavy metals in Compositae were investigated. The soil of polluted area was seriously polluted by three heavy metals, CD, Pb, Zn, and its content was higher than that of National soil Environment Standard (GB15618-1995), which exceeded the standard of 37.7U 5.7 and 8.9 times, respectively. The contents of CD Pb and Zn in plants are above the normal range. Chrysanthemum chrysanthemum and Artemisia chrysanthemum have strong migration and enrichment ability to CD, which is suitable for the ecological remediation of CD contaminated soil. The CD contents in stems and leaves of Chrysanthemum chrysanthemum were 159.6 mg / kg ~ (-1) and 159.6 mg / kg ~ (-1), respectively, which exceeded the critical criteria for CD superenrichment plants. It was found that Artemisia chrysanthemum had the basic characteristics of CD superenrichment plants. It was found that CD, Pb and Zn were mainly distributed in vacuolar soluble components and cell walls in the underground and aboveground parts of 3 species of Compositae. Most of the heavy metals in plants were extracted from sodium chloride with low migration. Therefore, vacuolation, cell wall fixation and chemical forms of heavy metals with low activity may be an important tolerance mechanism for three species of Compositae to deal with heavy metal stress, compared with Artemisia annua. CD in stems and leaves of chrysanthemum chrysanthemum and artichoke chrysanthemum were more stored in vacuole, and the accumulation ratio of "active state" CD in shoot was lower than that in root system, which may be an important way of tolerance and accumulation of cadmium in Artemisia chrysanthemum and Chrysanthemum chrysanthemum.
【作者单位】：中国科学院地球化学研究所环境地球化学国家重点实验室;中国科学院地理科学与资源研究所环境修复中心;中国科学院大学;
【基金】：国家自然科学基金项目(41425014,41625006) 中国博士后科学基金项目(2015M582578) 国家重点基础研究发展规划(973)项目(2014CB238906) 中国科学院特色研究所“典型区域土壤和地下水污染修复的综合技术方案与集成示范”项目
【分类号】：X173;X753

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