Publication Date:
1997-08-01
Description:
In the Gramineae, the cyclic hydroxamic acids 2,4-dihydroxy-1, 4-benzoxazin-3-one (DIBOA) and 2,4-dihydroxy-7-methoxy-1, 4-benzoxazin-3-one (DIMBOA) form part of the defense against insects and microbial pathogens. Five genes, Bx1 through Bx5, are required for DIBOA biosynthesis in maize. The functions of these five genes, clustered on chromosome 4, were demonstrated in vitro. Bx1 encodes a tryptophan synthase alpha homolog that catalyzes the formation of indole for the production of secondary metabolites rather than tryptophan, thereby defining the branch point from primary to secondary metabolism. Bx2 through Bx5 encode cytochrome P450-dependent monooxygenases that catalyze four consecutive hydroxylations and one ring expansion to form the highly oxidized DIBOA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frey, M -- Chomet, P -- Glawischnig, E -- Stettner, C -- Grun, S -- Winklmair, A -- Eisenreich, W -- Bacher, A -- Meeley, R B -- Briggs, S P -- Simcox, K -- Gierl, A -- New York, N.Y. -- Science. 1997 Aug 1;277(5326):696-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Genetik, Technische Universitat Munchen, Lichtenbergstrasse 4, 85747 Garching, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9235894" target="_blank"〉PubMed〈/a〉
Keywords:
Benzoxazines
;
Cloning, Molecular
;
Crosses, Genetic
;
Cytochrome P-450 Enzyme System/genetics/metabolism
;
DNA Transposable Elements
;
*Genes, Plant
;
Hydroxylation
;
Indoles/metabolism
;
Molecular Sequence Data
;
Oxazines/*metabolism
;
Plant Shoots/metabolism
;
Substrate Specificity
;
Tryptophan Synthase/genetics/metabolism
;
Zea mays/*genetics/metabolism
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
Permalink
