Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Home
Search
Quick Search
Advanced
Fulltext
Browse
Collections
Persons
My eDoc
Session History
Login
Name:
Password:
Documentation
Help
Support Wiki
Direct access to
document ID:


          Institute: MPI für Pflanzenzüchtungsforschung     Collection: Dept. Plant Developmental Biology (George Coupland)     Display Documents



ID: 42397.0, MPI für Pflanzenzüchtungsforschung / Dept. Plant Developmental Biology (George Coupland)
Regulation of transcript levels of the Arabidopsis cytochrome P450 genes involved in brassinosteroid biosynthesis
Authors:Bancos, S.; Nomura, T.; Sato, T.; Molnar, G.; Bishop, G. J.; Koncz, C.; Yokota, T.; Nagy, F.; Szekeres, M.
Language:English
Date of Publication (YYYY-MM-DD):2002-09
Title of Journal:Plant Physiology
Journal Abbrev.:Plant Physiol.
Volume:130
Issue / Number:1
Start Page:504
End Page:513
Review Status:Peer-review
Audience:Experts Only
Abstract / Description:Cytochrome P450 enzymes of the closely related CYP90 and CYP85 families catalyze essential oxidative reactions in the biosynthesis of brassinosteroid (BR) hormones. Arabidopsis CYP90B1/DWF4 and CYP90A1/CPD are responsible for respective C- 22 and C-23 hydroxylation of the steroid side chain and CYP85A1 catalyzes C-6 oxidation of 6-deoxo intermediates, whereas the functions of CYP90C1/ROT3, CYP90D1, and CYP85A2 are still unknown, Semiquantitative reverse transcriptase-polymerase chain reaction analyses show that transcript levels of CYP85 and CYP90 genes are down-regulated by brassinolide, the end product of the BR biosynthesis pathway. Feedback control of the CYP90C1, CYP90D1, and CYP85A2 genes by brassinolide suggests that the corresponding enzymes might also participate in BR synthesis. CYP85 and CYP90 mRNAs show strong and transient accumulation during the 1st week of seedling development, as well as characteristic organ-specific distribution. Transcripts of CYP90A1 and CYP85A2 are preferentially represented in shoots and CYP90C1, CYP90D1, and CYP85A1 mRNAs are more abundant in roots, whereas CYP90B1 is ubiquitously expressed. Remarkably, the spatial pattern of CYP90A1 expression is maintained in the BR-insensitive cbb2 mutant, indicating the independence of organ-specific and BR-dependent regulation. Quantitative gas chromatography-mass spectrometry analysis of endogenous BRs in shoots and roots of Arabidopsis, pea (Pisum sativum), and tomato (Lycopersicon esculentum) reveal similar partitioning patterns of BR intermediates in these species. Inverse correlation between CYP90A1/ CPD transcript levels and the amounts of the CYP90A1 substrate 6-deoxocathasterone in shoots and roots suggests that transcriptional regulation plays an important role in controlling BR biosynthesis.
Comment of the Author/Creator:Date: 2002, SEP
External Publication Status:published
Document Type:Article
Communicated by:N.N.
Affiliations:MPI für Pflanzenzüchtungsforschung
External Affiliations:Hungarian Acad Sci, Biol Res Ctr, Inst Plant Biol, POB 521, H-; 6701 Szeged, Hungary; Hungarian Acad Sci, Biol Res Ctr, Inst Plant Biol, H-6701 Szeged, Hungary; Teikyo Univ, Dept Biosci, Utsunomiya, Tochigi 3208551, Japan; Univ Wales, Inst Biol Sci, Aberystwyth SY23 3DD, Dyfed, Wales; Max Planck Inst Zuchtungsforsch, D-50829 Cologne, Germany
Identifiers:ISI:000178087700050 [ID No:1]
ISSN:0032-0889 [ID No:2]
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.