摘要
以白玉凤尾蕨和印度芥菜为实验材料，采用温室水培方法研究两种植物在人工添加不同形态（三价无机锑、五价无机锑和三甲基锑）与不同水平锑（白玉凤尾蕨为30和50 mg L-1，印度芥菜为5和20 mg L-1）处理条件下的生长状况.以不加锑处理作为对照，同时分析锑在两种植物不同部位的富集与形态转化.结果表明，白玉凤尾蕨与印度芥菜对3种形态的锑均可出现显著的吸收富集，白玉凤尾蕨地上部和根部锑含量最高分别达到816 mg kg-1和6065 mg kg-1，印度芥菜地上部和根部锑含量最高分别达到322 mg kg-1和2663 mg kg-1；两种植物对不同形态锑的富集能力均为三价锑（Sb（Ⅲ））〉五价锑（Sb（Ⅴ））〉甲基锑（TMSb），且主要富集于根部.Sb（Ⅴ）处理下，白玉凤尾蕨与印度芥菜地上部80%以上转化为Sb（Ⅲ），反映两种植物均具有很强的将Sb（Ⅴ）转化为Sb（Ⅲ）的能力；Sb（Ⅲ）处理下，白玉凤尾蕨与印度芥菜对Sb（Ⅲ）的转化较少，地上部与根部只有不到5%的Sb（Ⅲ）转化为Sb（Ⅴ）；白玉凤尾蕨可直接吸收TMSb，并有31%-46%被转化为无机的Sb（Ⅲ）和Sb（Ⅴ），而印度芥菜则100%将TMSb转化为无机的Sb（Ⅲ）和Sb（Ⅴ）.植物对有机锑直接吸收转运并将其转化为三价锑的能力可能是植物对锑富集的重要机制.
Antimony （Sb） toxicity and contamination have become a growing concern in recent years. Remediation of Sb contamination using plants may be an effective approach. One set of hydroponic trials was conducted using Pteris cretica and Brassica Juncea. Plants were grown for 2 weeks in nutrient solution containing different rates （P. cretica： 30 and 50 mg L-1; B. juncea： 5 and 50 mg L-1） and different speciation of Sb, with no Sb added as the control, to investigate the characteristics of plant uptake, accumulation, and transformation of Sb. The results showed that P. cretica and B. juncea can greatly accumulate Sb, in the treatments of Sb（Ⅲ）, Sb（V）, and TMSb, and the highest concentrations in the aboveground parts and roots of P. cretica were 816 mg kg-1 and 6065 mg kg-1, respectively; while those were 322 mg kg-1 and 2663 mg kg-1 for B. juncea. The accumulation and transfer ability of Sb followed an order of Sb（Ⅲ）〉 Sb（V）〉TMSb in both plants. Sb（V） was mostly transformed into Sb（Ⅲ）, with above 80% of transformation rates in the aboveground parts of the two plants when treated with Sb（V）. Sb（Ⅲ） was mostly taken up in its original species, with only 5% of Sb（Ⅲ） being transformed into Sb（V） in the plants. When treated with TMSb, P. cretica could take up and transfer more than 50% of TMSb from roots to aboveground parts without changing the species, with remaining 31%~46% TMSb being transformed into Sb（Ⅲ） and Sb（V）, mainly Sb （Ⅲ）; while in B. juncea no TMSb was detected due to the complete transformation into inorganic Sb. We suggest that the ability to direct uptake, accumulate and transfer TMSb without species transformation may probably be involved in the mechanism of antimony accumulation in plants.
出处
《环境科学学报》
CAS
CSCD
北大核心
2014年第3期720-727,共8页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.40971264,10979052)~~
