BRX promotes Arabidopsis shoot growth.

Détails

ID Serval
serval:BIB_1523A28003E2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
BRX promotes Arabidopsis shoot growth.
Périodique
New Phytologist
Auteur(s)
Beuchat J., Scacchi E., Tarkowska D., Ragni L., Strnad M., Hardtke C.S.
ISSN
1469-8137 (Electronic)
ISSN-L
0028-646X
Statut éditorial
Publié
Date de publication
2010
Volume
188
Numéro
1
Pages
23-29
Langue
anglais
Résumé
? BREVIS RADIX (BRX) has been identified through a loss-of-function allele in the Umkirch-1 accession in a natural variation screen for Arabidopsis root growth vigor. Physiological and gene expression analyses have suggested that BRX is rate limiting for auxin-responsive gene expression by mediating cross-talk with the brassinosteroid pathway, as impaired root growth and reduced auxin perception of brx can be (partially) rescued by external brassinosteroid application. ? Using genetic tools, we show that brx mutants also display significantly reduced cotyledon and leaf growth. ? Similar to the root, the amplitude and penetrance of this phenotype depends on genetic background and shares the physiological features, reduced auxin perception and brassinosteroid rescue. Furthermore, reciprocal grafting experiments between mutant and complemented brx shoot scions and root stocks suggest that the shoot phenotypes are not an indirect consequence of the root phenotype. Finally, BRX gain-of-function lines display epinastic leaf growth and, in the case of dominant negative interference, increased epidermal cell size. Consistent with an impact of BRX on brassinosteroid biosynthesis, this phenotype is accompanied by increased brassinosteroid levels. ? In summary, our results demonstrate a ubiquitous, although quantitatively variable role of BRX in modulating the growth rate in both the root and shoot.
Mots-clé
Arabidopsis/cytology, Arabidopsis/growth & development, Arabidopsis Proteins/metabolism, Cholestanols/metabolism, Cotyledon/anatomy & histology, Cotyledon/cytology, Mutation/genetics, Organ Size, Phenotype, Plant Leaves/anatomy & histology, Plant Leaves/growth & development, Plant Roots/growth & development, Plant Roots/metabolism, Plant Shoots/cytology, Plant Shoots/growth & development, Steroids, Heterocyclic/metabolism
Pubmed
Web of science
Création de la notice
18/05/2011 11:44
Dernière modification de la notice
03/03/2018 14:08
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