Arsenic uptake and speciation in the rootless duckweed Wolffia globosa.
Arsenic uptake and speciation in the rootless duckweed Wolffia globosa.
复制标题
DOI：
10.1111/j.1469-8137.2008.02758.x
复制
发表时间：
2009-04
期刊：
影响因子：
--
通讯作者：
Xin Zhang;F. Zhao;Qing-Fei Huang;Paul N. Williams;Guoxin Sun;Yong-guan Zhu
中科院分区：
文献类型：
--
作者：
Xin Zhang;F. Zhao;Qing-Fei Huang;Paul N. Williams;Guoxin Sun;Yong-guan Zhu
浮萍是一种常见于稻田和水生环境中的水生植物。在这里，我们调查砷（As）的积累，形态和无根浮萍Wolffia globosa和其潜在的砷植物过滤的耐受性。在1 μ m砷酸盐培养基中，W. globosa积累2至10倍以上的As比其他四个浮萍或红萍种测试。W.球形藻对砷的累积量大于1000 mg·kg ~（-1），耐受量可达400 mg·kg ~（-1）。在低浓度范围内，砷酸盐和亚砷酸盐的吸收速率相似，但在高浓度范围内，亚砷酸盐以更快的速率被吸收。砷是主要的砷物种（c。砷暴露的浮萍中砷的含量均占总砷含量的90%以上。W. globosa对外部砷酸盐的耐受性高于亚砷酸盐，但其内部耐受性相似。W. globosa能迅速降低溶液中的砷酸盐，但也能使砷酸盐流出。无根萍是一种强砷积累植物，由于无根萍不存在根-叶转运障碍，是研究砷吸收和代谢的理想模式植物。
Duckweeds are a common macrophyte in paddy and aquatic environments. Here, we investigated arsenic (As) accumulation, speciation and tolerance of the rootless duckweed Wolffia globosa and its potential for As phytofiltration. When grown with 1 microm arsenate, W. globosa accumulated two to 10 times more As than four other duckweed or Azolla species tested. W. globosa was able to accumulate > 1000 mg As kg(-1) in frond dry weight (DW), and tolerate up to 400 mg As kg(-1) DW. At the low concentration range, uptake rate was similar for arsenate and arsenite, but at the high concentration range, arsenite was taken up at a faster rate. Arsenite was the predominant As species (c. 90% of the total extractable As) in both arsenate- and arsenite-exposed duckweed. W. globosa was more resistant to external arsenate than arsenite, but showed a similar degree of tolerance internally. W. globosa decreased arsenate in solution rapidly, but also effluxed arsenite. Wolffia globosa is a strong As accumulator and an interesting model plant to study As uptake and metabolism because of the lack of a root-to-frond translocation barrier.