Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China.
Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental & Resource Science, Zhejiang University, Hangzhou, 310058, China; Zhejiang Provincial Key Laboratory of Subtropic Soil and Plant Nutrition, Zhejiang University, Hangzhou 310058, China.
Environ Pollut. 2020 Aug;263(Pt B):114401. doi: 10.1016/j.envpol.2020.114401. Epub 2020 Mar 19.
High sensitivity towards Cu toxicity is problematic when using some hyperaccumulator plants for phytoremediation of soils with mixed contamination of Cu. Sedum alfredii, a Cd/Zn co-hyperaccumulator and Pb accumulator, is widely used for remediation of Cd, Zn, and Pb co-contaminated soils in China. In this paper, the tolerance and accumulation ability of S. alfredii towards Cu stress and its potential for phytoremediation of multi-metal polluted soils have been studied. Both the hyperaccumulating ecotype (HE) and non-hyperaccumulating ecotype (NHE) of S. alfredii accumulated high Cu in the roots and translocated minimal Cu to the shoots, and Cu in the stems and leaves mostly restricted in the vascular tissues (phloem zone). The HE plants, however, exhibited high Cu resistance with stimulated lateral root growth and increased chlorophyll content under 10 μM Cu treatment. XANES analysis showed that Cu in HE roots comprised Cu (46.7%), Cu-histidine (35.2%) and Cu-cell wall (18.1%). The NHE under Cu stress showed decreased biomass, reduced leaf chlorophyll content, altered root architecture, and higher Cu localized to root cell wall as compared with the HEs. Potted HE plants thrived six months in multi-metal contaminated soils including 3897 mg kg available Cu. In conclusion, HE S alfredii is highly tolerant toward Cu due to metal homeostasis in root cells. Therefore, this plant has great potential to remediate Zn, Cd, and Pb contaminated soils those also contain high levels of Cu.
超富集植物在修复 Cu 混合污染土壤时，对 Cu 毒性的高敏感性是一个问题。Sedum alfredii 是一种 Cd/Zn 共超富集植物和 Pb 积累植物，在中国被广泛用于修复 Cd、Zn 和 Pb 复合污染土壤。本文研究了 S. alfredii 对 Cu 胁迫的耐受性和积累能力及其对多金属污染土壤的植物修复潜力。S. alfredii 的超积累生态型（HE）和非超积累生态型（NHE）在根部积累了大量的 Cu，并将最少的 Cu 转运到地上部分，而茎和叶中的 Cu 主要局限在维管束（韧皮部）中。然而，HE 植物在 10 μM Cu 处理下表现出较高的 Cu 抗性，侧根生长和叶绿素含量增加。XANES 分析表明，HE 根中的 Cu 由 Cu（46.7%）、Cu-组氨酸（35.2%）和 Cu-细胞壁（18.1%）组成。与 HEs 相比，Cu 胁迫下的 NHE 表现出生物量减少、叶片叶绿素含量降低、根系结构改变以及更多的 Cu 定位于细胞壁。盆栽 HE 植物在包括 3897 mg kg 有效 Cu 的多金属污染土壤中生长了六个月。总之，由于根细胞中的金属稳态，HE S alfredii 对 Cu 具有高度耐受性。因此，该植物具有修复 Zn、Cd 和 Pb 污染土壤的巨大潜力，这些土壤也含有高水平的 Cu。
