College of Landscape Architecture, Sichuan Agricultural University, Wenjiang, Chengdu, Sichuan, 611130, China.
Department of Environmental Sciences and Engineering, Government College University, Faisalabad, 38000, Pakistan.
J Hazard Mater. 2019 Jun 5;371:233-242. doi: 10.1016/j.jhazmat.2019.03.016. Epub 2019 Mar 5.
The identification of hyperaccumulators is a key step for the phytoextraction of contaminated soils. However, few cadmium (Cd) hyperaccumulators have been identified in the plant kingdom. In our previous field investigations, Lantana camara L. plants exhibited some traits of hyperaccumulators. To confirm whether this species is a Cd hyperaccumulator, laboratory dose-gradient experiments and field sample analysis experiments were first designed and implemented in an integrated manner. The results showed that lantana plants did not exhibit any visible damage or marked reduction in shoot biomass when grown in Cd-contaminated soil with less than 100 mg kg Cd. Moreover, the lantana plants exhibited high Cd tolerance with effective coordination of photosynthesis and rapid reactive oxygen species scavenging. Most importantly, the bioaccumulation factors (BFs) and translocation factors (TFs) were greater than 1.0 in all the Cd treatments, while the Cd concentrations in the shoots were all greater than those in the roots and were also greater than 100 mg kg, the threshold value for a Cd hyperaccumulator. Our data provide comprehensive evidence that lantana plants have the typical characteristics of a Cd hyperaccumulator and thus can be regarded as potential Cd-hyperaccumulating plants for the restoration of Cd-polluted soils.
超积累植物的鉴定是植物修复受污染土壤的关键步骤。然而，在植物界中，很少有被鉴定为镉（Cd）超积累植物。在我们之前的野外调查中，马缨丹（Lantana camara L.）植物表现出一些超积累植物的特征。为了确定该物种是否为 Cd 超积累植物，我们首先综合设计并实施了实验室剂量梯度实验和野外样本分析实验。结果表明，当马缨丹植物在 Cd 污染土壤中生长时，其 Cd 浓度低于 100mg/kg 时，植物没有表现出任何可见的损伤或地上生物量明显减少。此外，马缨丹植物表现出较高的 Cd 耐受性，光合作用和快速活性氧清除之间有效协调。最重要的是，在所有 Cd 处理中，生物积累因子（BFs）和转移因子（TFs）均大于 1.0，而地上部 Cd 浓度均大于根部 Cd 浓度，且大于 100mg/kg，这是 Cd 超积累植物的阈值。我们的数据提供了全面的证据，表明马缨丹植物具有 Cd 超积累植物的典型特征，因此可以被视为修复 Cd 污染土壤的潜在 Cd 超积累植物。
