Plant and Soil

, Volume 391, Issue 1–2, pp 195–205

The concentration of selenium matters: a field study on mercury accumulation in rice by selenite treatment in qingzhen, Guizhou, China

  • Yu-Feng Li
  • Jiating Zhao
  • Yunyun Li
  • Hanjun Li
  • Junfang Zhang
  • Bai Li
  • Yuxi Gao
  • Chunying Chen
  • Manyi Luo
  • Rui Huang
  • Jun Li
Regular Article

DOI: 10.1007/s11104-015-2418-4

Cite this article as:
Li, YF., Zhao, J., Li, Y. et al. Plant Soil (2015) 391: 195. doi:10.1007/s11104-015-2418-4

Abstract

Aims

The consumption of rice grain produced in mercury (Hg) contaminated soil was identified as a major route of dietary Hg exposure. The aims were 1) to determine the most suitable concentration of Se that can lead to least Hg accumulation in rice grain in real Hg contaminated paddy field in Qingzhen, and 2) to elucidate the possible mechanism of the protection against the phytotoxicity of Hg in rice by Se.

Methods

Rice plants were treated with different concentrations (0, 0.01, 0.1, 0.5, 1 and 5 μg/mL) of sodium selenite in a real paddy field in Qingzhen, Guizhou, China. The concentrations of Hg and Se in soil, stream water, rice tissues, and the seed setting rate (SSR) and thousand seed weight (TSW) were checked. The distribution and chemical forms of Hg and Se in rice root were studied by XRF and XAS.

Results

Treating the rice plants with 0.5 μg/mL of sodium selenite achieved the lowest Hg accumulation in rice grain while the highest SSR and TSW. In rice root, XRF found decreased Hg uptake, and XAS found Hg-Se complexes were formed. These findings, together with the formation of biological barriers like iron plaque, could explain the decreased accumulation of Hg in rice grain at Se levels below 0.5 μg/mL. Se concentrations over 0.5 μg/mL led to increased Hg accumulation and decreased SSR and TSW, which were ascribed to the significantly increased Se accumulation in rice grain.

Conclusions

This field study suggest that treatment with appropriate level of Se (0.5 μg/mL in this study) is an efficient way to reduce Hg accumulation in rice and increase rice yield and quality, thereafter to protect the health of the rice-dependent populations in Hg-contaminated area.

Keywords

Rice Mercury Selenium XRF XAS Seed setting rate Thousand seed weight 

Supplementary material

11104_2015_2418_MOESM1_ESM.docx (34 kb)
S 1Analytical Methods and Quality Control (DOCX 33 kb)
11104_2015_2418_MOESM2_ESM.docx (33 kb)
S 2XRF beamline in SSRF (DOCX 33 kb)
11104_2015_2418_MOESM3_ESM.docx (33 kb)
S 3Hg Speciation by XAS (DOCX 33 kb)
11104_2015_2418_MOESM4_ESM.docx (86 kb)
Figure S1The normalized XANES spectra of rice roots and the standard compounds. (DOCX 85 kb)
11104_2015_2418_MOESM5_ESM.docx (177 kb)
Figure S2The LCF fitting of the XANES spectra. (a) Fitting the spectrum of the control rice root; (b) Fitting the spectrum of Se treated rice root. (DOCX 176 kb)

Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  • Yu-Feng Li
    • 1
  • Jiating Zhao
    • 1
  • Yunyun Li
    • 1
  • Hanjun Li
    • 1
  • Junfang Zhang
    • 2
  • Bai Li
    • 1
  • Yuxi Gao
    • 1
  • Chunying Chen
    • 3
  • Manyi Luo
    • 4
  • Rui Huang
    • 4
  • Jun Li
    • 4
  1. 1.State Environmental Protection Engineering Center for Mercury Pollution Prevention and Control, and CAS Key Laboratory for Biomedical Effects of Nanomateriasl and Nanosafety, Institute of High Energy PhysicsChinese Academy of SciencesBeijingChina
  2. 2.Guizhou Institute of Environmental Science and DesigningGuiyangChina
  3. 3.National Center for Nanoscience and TechnologyBeijingChina
  4. 4.Beijing National Day SchoolBeijingChina

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