Arsenic uptake and speciation in the rootless duckweed Wolffia globosa

Xin Zhang, Fang-Jie Zhao, Qing Huang, Paul N. Williams, Guo-Xin Sun, Yong-Guan Zhu*

*Corresponding author for this work

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

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 mu M 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

Original languageEnglish
Pages (from-to)421-428
Number of pages8
JournalThe New phytologist
Volume182
Issue number2
DOIs
Publication statusPublished - 2009

Keywords

  • TOLERANCE
  • Wolffia globosa
  • arsenic
  • HOLCUS-LANATUS
  • HYPERACCUMULATOR PTERIS-VITTATA
  • CONTAMINATED SOILS
  • duckweed
  • UPTAKE KINETICS
  • RICE GRAIN
  • ACCUMULATION
  • speciation
  • PHYTOCHELATINS
  • tolerance
  • FERN
  • PLANTS

Cite this