Plant Physiology Preview
Published on February 6, 2003; 10.1104/pp.014787
Received September 17, 2002
Returned for revision November 8, 2002
Accepted November 29, 2002
Chemical Form and Distribution of Selenium and Sulfur in the Selenium Hyperaccumulator Astragalus bisulcatus
Ingrid J. Pickering , Carrie Wright , Ben Bubner , Danielle Ellis , Michael W. Persans , Eileen Y. Yu , Graham N. George , Roger C. Prince , and David E. Salt *
Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (D.E.S., D.E.); Northern Arizona University, Flagstaff, Arizona 86011 (C.W., B.B.); Department of Biology, University of Texas-Pan American, Edinburg, Texas 78539 (M.W.P.); Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford Linear Accelerator Center, Menlo Park, California 94025 (I.J.P., E.Y.Y., G.N.G.); and ExxonMobil Research and Engineering Company, Annandale, New Jersey 08801 (R.C.P.).
* Corresponding author; email: dsalt{at}purdue.edu.
In its natural habitat, Astragalus bisulcatus can accumulate up to 0.65% (w/w) selenium (Se) in its shoot dry weight. X-ray absorption spectroscopy has been used to examine the selenium biochemistry of A. bisulcatus. High concentrations of the nonprotein amino acid Se-methylseleno-cysteine (Cys) are present in young leaves of A. bisulcatus, but in more mature leaves, the Se-methylseleno-Cys concentration is lower, and selenate predominates. Seleno-Cys methyltransferase is the enzyme responsible for the biosynthesis of Se-methylseleno-Cys from seleno-Cys and S-methyl-methionine. Seleno-Cys methyltransferase is found to be expressed in A. bisulcatus leaves of all ages, and thus the biosynthesis of Se-methylseleno-Cys in older leaves is limited earlier in the metabolic pathway, probably by an inability to chemically reduce selenate. A comparative study of sulfur (S) and Se in A. bisulcatus using x-ray absorption spectroscopy indicates similar trends for oxidized and reduced Se and S species, but also indicates that the proportions of these differ significantly. These results also indicate that sulfate and selenate reduction are developmentally correlated, and they suggest important differences between S and Se biochemistries.
This article has been cited by other articles:
|
|
|
|
 
T. Punshon, M. L. Guerinot, and A. Lanzirotti
Using synchrotron X-ray fluorescence microprobes in the study of metal homeostasis in plants
Ann. Bot.,
March 1, 2009;
103(5):
665 - 672.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Tamaoki, J. L. Freeman, and E. A.H. Pilon-Smits
Cooperative Ethylene and Jasmonic Acid Signaling Regulates Selenite Resistance in Arabidopsis
Plant Physiology,
March 1, 2008;
146(3):
1219 - 1230.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. Young, N. Westcott, C. Christensen, J. Terry, D. Lydiate, and M. Reaney
Inferring the Geometry of Fourth-Period Metallic Elements in Arabidopsis thaliana Seeds using Synchrotron-Based Multi-Angle X-ray Fluorescence Mapping
Ann. Bot.,
November 1, 2007;
100(6):
1357 - 1365.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
E. El Kassis, N. Cathala, H. Rouached, P. Fourcroy, P. Berthomieu, N. Terry, and J.-C. Davidian
Characterization of a Selenate-Resistant Arabidopsis Mutant. Root Growth as a Potential Target for Selenate Toxicity
Plant Physiology,
March 1, 2007;
143(3):
1231 - 1241.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. L. Freeman, L. H. Zhang, M. A. Marcus, S. Fakra, S. P. McGrath, and E. A.H. Pilon-Smits
Spatial Imaging, Speciation, and Quantification of Selenium in the Hyperaccumulator Plants Astragalus bisulcatus and Stanleya pinnata
Plant Physiology,
September 1, 2006;
142(1):
124 - 134.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. W. FINLEY
Proposed Criteria for Assessing the Efficacy of Cancer Reduction by Plant Foods Enriched in Carotenoids, Glucosinolates, Polyphenols and Selenocompounds
Ann. Bot.,
June 1, 2005;
95(7):
1075 - 1096.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. M. Lyi, L. I. Heller, M. Rutzke, R. M. Welch, L. V. Kochian, and L. Li
Molecular and Biochemical Characterization of the Selenocysteine Se-Methyltransferase Gene and Se-Methylselenocysteine Synthesis in Broccoli
Plant Physiology,
May 1, 2005;
138(1):
409 - 420.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
