Quantitative, chemically specific imaging of selenium transformation in plants.

  • Pickering I
  • Prince R
  • Salt D
 et al. 
  • 68

    Readers

    Mendeley users who have this article in their library.
  • 137

    Citations

    Citations of this article.

Abstract

Quantitative, chemically specific images of biological systems would be invaluable in unraveling the bioinorganic chemistry of biological tissues. Here we report the spatial distribution and chemical forms of selenium in Astragalus bisulcatus (two-grooved poison or milk vetch), a plant capable of accumulating up to 0.65% of its shoot dry biomass as Se in its natural habitat. By selectively tuning incident x-ray energies close to the Se K-absorption edge, we have collected quantitative, 100-microm-resolution images of the spatial distribution, concentration, and chemical form of Se in intact root and shoot tissues. To our knowledge, this is the first report of quantitative concentration-imaging of specific chemical forms. Plants exposed to 5 microM selenate for 28 days contained predominantly selenate in the mature leaf tissue at a concentration of 0.3-0.6 mM, whereas the young leaves and the roots contained organoselenium almost exclusively, indicating that the ability to biotransform selenate is either inducible or developmentally specific. While the concentration of organoselenium in the majority of the root tissue was much lower than that of the youngest leaves (0.2-0.3 compared with 3-4 mM), isolated areas on the extremities of the roots contained concentrations of organoselenium an order of magnitude greater than the rest of the root. These imaging results were corroborated by spatially resolved x-ray absorption near-edge spectra collected from selected 100 x 100 microm(2) regions of the same tissues.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Get full text

Authors

  • I J Pickering

  • R C Prince

  • D E Salt

  • G N George

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free