Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
Sci Total Environ. 2020 Jun 15;721:137581. doi: 10.1016/j.scitotenv.2020.137581. Epub 2020 Feb 25.
A phytoextraction experiment with five Cd hyperaccumulators (Amaranthus hypochondriacus, Celosia argentea, Solanum nigrum, Phytolacca acinosa and Sedum plumbizincicola) was conducted in two soils with different soil pH (5.93 and 7.43, respectively). Most accumulator plants grew better in the acidic soil, with 19.59-39.63% higher biomass than in the alkaline soil, except for S. plumbizincicola. The potential for a metal-contaminated soil to be cleaned up using phytoremediation is determined by the metal uptake capacity of hyperaccumulator, soil properties, and mutual fitness of plant-soil relationships. In the acidic soil, C. argentea and A. hypochondriacus extracted the highest amount of Cd (1.03 mg pot and 0.92 mg pot, respectively). In the alkaline soil, S. plumbizincicola performed best, mainly as a result of high Cd accumulation in plant tissue (541.36 mg kg). Most plants achieved leaf Cd bioconcentration factor (BCF) of >10 in the acidic soil, compared to <4 in the alkaline soil. Soil Cd availability was chiefly responsible for such contrasting metal extraction capacity, with 5.02% fraction and 48.50% fraction of total Cd being available in the alkaline and acidic soil, respectively. In the alkaline soil, plants tended to increase rhizosphere soil available Cd mainly through excreting more low molecular weight organic acids, not through changing the soil pH. In the acidic soil, plants slightly decreased soil available Cd. Those species which have high Ca, Zn, Fe uptake capacity extract more Cd from soil, and a positive correlation was found between the concentrations of Cd and Ca, Zn, Fe in leaves. Soil available Ca, Mg, SO, Cl did not play a key role in Cd uptake by plants. In summary, acidic soil was of higher potential to recover from Cd contamination by phytoextraction, while in the alkaline soil, S. plumbizincicola showed potential for Cd phytoextraction.
进行了一项在两种土壤 pH 值（分别为 5.93 和 7.43）不同的条件下，用 5 种 Cd 超富集植物（反枝苋、鸡冠花、龙葵、商陆和松叶景天）进行的植物提取实验。除了松叶景天外，大多数富集植物在酸性土壤中生长得更好，生物量比在碱性土壤中高出 19.59-39.63%。利用植物修复来净化受金属污染的土壤的潜力取决于超富集植物对金属的吸收能力、土壤特性以及植物与土壤关系的相互适应性。在酸性土壤中，鸡冠花和反枝苋吸收的 Cd 量最高（分别为 1.03 毫克盆和 0.92 毫克盆）。在碱性土壤中，松叶景天表现最好，主要是因为植物组织中 Cd 积累量高（541.36 毫克公斤）。大多数植物在酸性土壤中的叶片 Cd 生物浓缩因子（BCF）大于 10，而在碱性土壤中则小于 4。土壤 Cd 的有效性是造成这种截然不同的金属提取能力的主要原因，碱性和酸性土壤中分别有 5.02%和 48.50%的总 Cd 是可利用的。在碱性土壤中，植物通过排泄更多的低分子量有机酸来增加根际土壤中可利用的 Cd，而不是通过改变土壤 pH 值。在酸性土壤中，植物略微降低了土壤中可利用的 Cd。那些具有高 Ca、Zn、Fe 吸收能力的物种从土壤中提取更多的 Cd，并且在叶片中 Cd 浓度与 Ca、Zn、Fe 之间存在正相关关系。土壤中可利用的 Ca、Mg、SO4、Cl 对植物吸收 Cd 没有起到关键作用。总之，酸性土壤更有可能通过植物提取来恢复 Cd 污染，而在碱性土壤中，松叶景天显示出 Cd 植物提取的潜力。
