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


     

Plant Physiology Preview
Published on January 11, 2008; 10.1104/pp.107.111237

OPEN ACCESS ARTICLE
This Article
Free via Open Access: OA
Right arrow Full Text (Plant Physiology Preview (PDF))
Right arrow Supplemental Data
Right arrowOA All Versions of this Article:
146/3/1053    most recent
pp.107.111237v1
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 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 Google Scholar
Google Scholar
Right arrow Articles by Jonczyk, R.
Right arrow Articles by Gierl, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jonczyk, R.
Right arrow Articles by Gierl, A.
Agricola
Right arrow Articles by Jonczyk, R.
Right arrow Articles by Gierl, A.

Received October 18, 2007
Accepted January 8, 2008

Elucidation of the final reactions of DIMBOA-glucoside biosynthesis in maize: Characterization of Bx6 and Bx7

Rafal Jonczyk , Holger Schmidt , Anne Osterrieder , Andreas Fießelmann , Katrin Schullehner , Martin Haslbeck , Dieter Sicker , Diana Hofmann , Nasser Yalpani , Carl Simmons , Monika Frey *, and Alfons Gierl

Technische Universitat Munchen, Lehrstuhl fur Genetik, Am Hochanger 8, 85354 Freising; Technische Universitat Munchen, Department Chemie, Lehrstuhl Biotechnologie, Lichtenbergstrasse 4, 85747 Garching; Institut for Organic Chemistry, Universitat Leipzig, Johannisallee 29 04103 Leipzig; Institut fur Analytische Chemie, Universitat Leipzig, Johannisallee 29, 04103 Leipzig; Pioneer Hi-Bred International, Inc., 7300 Northwest 62nd Avenue, P.O. Box 1004, Johnston, Iowa 50131

* Corresponding author; email: Monika.Frey{at}wzw.tum.de.

Benzoxazinoids have been identified in the early 1960s as secondary metabolites of the grasses that function as natural pesticides and exhibit allelopathic properties. Benzoxazinoids are synthesized in seedlings and stored as glucosides, the main aglucone moieties are DIBOA (2,4-dihydroxy-2H-1,4-benzoxazin-3(4H)-one) and DIMBOA (2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one). The genes of DIBOA-glucoside biosynthesis have previously been isolated and the enzymatic functions characterized. Here, the enzymes for conversion of DIBOA-glc to DIMBOA-glc are identified. DIBOA-glc is the substrate of the dioxygenase BX6, the produced TRIBOA-glc is metabolized by the methyltransferase BX7 to yield DIMBOA-glc. Both enzymes exhibit moderate Km-values (below 0.4 mM) and kcat values of 2.10 s-1 and 0.25 s-1, respectively. Although BX6 uses a glucosylated substrate, our localization studies indicate a cytoplasmatic localization of the dioxygenase. Bx6 and Bx7 are highest expressed in seedling tissue, a feature shared with the other Bx-genes. At present, Bx6 and Bx7 have no close relatives among the members of their respective gene families. Bx6 and Bx7 map to the cluster of Bx-genes on the short arm of chromosome 4.




This article has been cited by other articles:


Home page
 ScienceHome page
B. Field and A. E. Osbourn
Metabolic Diversification--Independent Assembly of Operon-Like Gene Clusters in Different Plants
Science, April 25, 2008; 320(5875): 543 - 547.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
ASPB Publications PLANT PHYSIOLOGY THE PLANT CELL
Copyright © 2008 by the American Society of Plant Biologists