Copper uptake by Elsholtzia splendens and Silene vulgaris and assessment of copper phytoavailability in contaminated soils.
Copper uptake by Elsholtzia splendens and Silene vulgaris and assessment of copper phytoavailability in contaminated soils.
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DOI：
10.1016/j.envpol.2003.09.019
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发表时间：
2004-02
影响因子：
8.9
通讯作者：
Jing Song;F. Zhao;Yong-ming Luo;S. McGrath;Hao Zhang
中科院分区：
文献类型：
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作者：
Jing Song;F. Zhao;Yong-ming Luo;S. McGrath;Hao Zhang
耐性和金属吸收是植物从污染土壤中提取金属所必需的两个基本特性。我们比较了香薷（Elsholtzia splendens）（以前报道为Cu超富集植物）和蝇子草（Silene vulgaris）（Imsbach种群，一种著名的Cu耐受排斥物种）的耐受性和Cu吸收，使用了30种Cu总浓度变化很大的土壤（19-8645 mg kg−1）。我们进一步研究了不同土壤测试方法预测植物金属吸收的有效性。结果表明，海州香薷和蝇子草对Cu都有一定的耐受性，蝇子草对Cu的耐受性最强。而海州香薷对Cu的吸收不明显，表现为典型的Cu排斥者。两种植物中Cu的浓度与1 M NH 4 NO3可提取Cu、土壤溶液Cu或DGT测定的有效Cu浓度的相关性比与土壤总Cu、EDTA可提取Cu或游离Cu 2+活性的相关性更密切。利用多元回归分析进一步研究了土壤溶液性质与根系铜含量的关系。结果表明，当游离Cu ~（2+）活性保持不变时，增加土壤溶液pH值可增加根系Cu ~（2+）的含量，表明土壤溶液pH值越高，植物对游离Cu ~（2+）的有效性越高。土壤溶液DOC对植物Cu ~（2+）的有效性有两种不同的作用：（1）络合Cu，降低Cu的有效性;（2）通过为游离Cu ~（2+）提供强缓冲，在相同的游离Cu ~（2+）活性水平下增加Cu的有效性。结果是一致的强度/容量的概念，植物有效性的金属在土壤中。
Tolerance and metal uptake are two essential characteristics required for phytoextraction of metals from contaminated soils. We compared tolerance and Cu uptake of Elsholtzia splendens (reported previously to be a Cu hyperaccumulator) with Silene vulgaris (the Imsbach population, a well-known Cu-tolerant excluder species), using 30 soils varying widely in total Cu concentration (19–8645 mg kg−1). We further investigated the effectiveness of different soil testing methods for predicting plant metal uptake. The results showed that both Elsholtzia splendens and Silene vulgaris were tolerant to Cu, especially Silene vulgaris. However, Elsholtzia splendens did not hyperaccumulate Cu, but behaved as a typical Cu excluder like Silene vulgaris. The concentrations of Cu in both plants correlated more closely with 1 M NH4NO3extractable Cu, soil solution Cu, or effective Cu concentration determined using DGT, than with soil total Cu, EDTA extractable Cu or free Cu2+activity. The relationships between soil solution properties and root Cu concentrations were further investigated using multiple regression. The results showed that increasing soil solution pH increased root Cu concentration when free Cu2+activity was held constant, suggesting a higher phytoavailability of free Cu2+at a higher pH. Soil solution DOC appeared to play two contrasting roles on the phytoavailability of Cu: (1) reducing Cu availability by complexing Cu; and (2) increasing Cu availability at the same level of free Cu2+activity by providing a strong buffer for free Cu2+. The results are consistent with the intensity/capacity concept for phytoavailability of metals in soils.