Speciation and distribution of arsenic and localization of nutrients in rice grains

E. Lombi, K. G. Scheckel, J. Pallon, Anne-Marie Carey, Yongguan Zhu, Andrew Alexander Meharg

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162 Citations (Scopus)

Abstract

Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro) nutrients in rice grains because these are key factors controlling bioavailability of nutrients and contaminants.

Bulk total and speciation analyses using high-pressure liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) and X-ray absorption near-edge spectroscopy (XANES) was complemented by spatially resolved microspectroscopic techniques (mu-XANES, mu-X-ray fluorescence (mu-XRF) and particle induced X-ray emission (PIXE)) to investigate both speciation and distribution of As and localization of nutrients in situ.

The distribution of As and micronutrients varied between the various parts of the grains (husk, bran and endosperm) and was characterized by element-specific distribution patterns. The speciation of As in bran and endosperm was dominated by As(III)-thiol complexes.

The results indicate that the translocation from the maternal to filial tissues may be a bottleneck for As accumulation in the grain. Strong similarities between the distribution of iron (Fe), manganese (Mn) and phosphorus (P) and between zinc (Zn) and sulphur (S) may be indicative of complexation mechanisms in rice grains.

Original languageEnglish
Pages (from-to)193-201
Number of pages9
JournalNew Phytologist
Volume184
Issue number1
DOIs
Publication statusPublished - 2009

Keywords

  • arsenic (As)
  • micronutrients
  • particle induced X-ray emission (PIXE)
  • rice grain
  • synchrotron
  • ORYZA-SATIVA L.
  • RISK-ASSESSMENT
  • PHYTOCHELATIN COMPLEXES
  • DIETARY EXPOSURE
  • HIGHER-PLANTS
  • ACCUMULATION
  • TRANSLOCATION
  • DETECTOR
  • CADMIUM

Cite this

Lombi, E., Scheckel, K. G., Pallon, J., Carey, A-M., Zhu, Y., & Meharg, A. A. (2009). Speciation and distribution of arsenic and localization of nutrients in rice grains. New Phytologist, 184(1), 193-201. https://doi.org/10.1111/j.1469-8137.2009.02912.x