Plant Physiol. Drug Metab Dispos
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
QUICK SEARCH:   [advanced]


     

Plant Physiology Preview
Published on April 29, 2005; 10.1104/pp.104.056549

This Article
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow All Versions of this Article:
138/1/409    most recent
pp.104.056549v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Web of Science (21)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lyi, S. M.
Right arrow Articles by Li, L.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lyi, S. M.
Right arrow Articles by Li, L.
Agricola
Right arrow Articles by Lyi, S. M.
Right arrow Articles by Li, L.

Received November 19, 2004
Returned for revision January 24, 2005
Accepted February 3, 2005

Molecular and Biochemical Characterization of the Selenocysteine Se-Methyltransferase Gene and Se-Methylselenocysteine Synthesis in Broccoli

Sangbom M. Lyi , Laurence I. Heller , Michael Rutzke , Ross M. Welch , Leon V. Kochian , and Li Li *

United States Department of Agriculture Agricultural Research Service, Plant, Soil and Nutrition Laboratory, Cornell University, Ithaca, New York 14853

* Corresponding author; email: ll37{at}cornell.edu.

Selenium (Se) plays an indispensable role in human nutrition and has been implicated to have important health benefits, including being a cancer preventative agent. While different forms of Se vary in their anticarcinogenic efficacy, Se-methylselenocysteine (SeMSC) has been demonstrated to be one of the most effective chemopreventative compounds. Broccoli (Brassica oleracea var. italica) is known for its ability to accumulate high levels of Se with the majority of the selenoamino acids in the form of Se-methylselenocysteine. Therefore, it serves as a good model to study the regulation of SeMSC accumulation in plants. A cDNA encoding selenocysteine Se-methyltransferase, the key enzyme responsible for SeMSC formation, was cloned from broccoli using a homocysteine S-methyltransferase gene probe from Arabidopsis (Arabidopsis thaliana). This clone, designated as BoSMT, was functionally expressed in Escherichia coli, and its identity was confirmed by its substrate specificity in the methylation of selenocysteine. The BoSMT gene represents a single copy sequence in the broccoli genome. Examination of BoSMT gene expression and SeMSC accumulation in response to selenate, selenite, and sulfate treatments showed that the BoSMT transcript and SeMSC synthesis were significantly up-regulated in plants exposed to selenate but were low in plants supplied with selenite. Simultaneous treatment of selenate with selenite significantly reduced SeMSC production. In addition, high levels of sulfate suppressed selenate uptake, resulting in a dramatic reduction of BoSMT mRNA level and SeMSC accumulation. Our results reveal that SeMSC accumulation closely correlated with the BoSMT gene expression and the total Se status in tissues and provide important information for maximizing the SeMSC production in this beneficial vegetable plant.




This article has been cited by other articles:


Home page
 Plant Physiol.Home page
X. Zhou, Y. Yuan, Y. Yang, M. Rutzke, T. W. Thannhauser, L. V. Kochian, and L. Li
Involvement of a Broccoli COQ5 Methyltransferase in the Production of Volatile Selenium Compounds
Plant Physiology, October 1, 2009; 151(2): 528 - 540.
[Abstract] [Full Text] [PDF]

Home page
 Cancer Prevention ResearchHome page
J.-I. Lee, H. Nian, A. J.L. Cooper, R. Sinha, J. Dai, W. H. Bisson, R. H. Dashwood, and J. T. Pinto
{alpha}-Keto Acid Metabolites of Naturally Occurring Organoselenium Compounds as Inhibitors of Histone Deacetylase in Human Prostate Cancer Cells
Cancer Prevention Research, July 1, 2009; 2(7): 683 - 693.
[Abstract] [Full Text] [PDF]

Home page
 Proc. Natl. Acad. Sci. USAHome page
J. Qin, B. P. Rosen, Y. Zhang, G. Wang, S. Franke, and C. Rensing
Arsenic detoxification and evolution of trimethylarsine gas by a microbial arsenite S-adenosylmethionine methyltransferase
PNAS, February 14, 2006; 103(7): 2075 - 2080.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY® THE PLANT CELL
Copyright © 2005 by the American Society of Plant Biologists