The short-rooted phenotype of the brevis radix mutant partly reflects root abscisic acid hypersensitivity.

Détails

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Etat: Serval
Version: Author's accepted manuscript
ID Serval
serval:BIB_F2585EF92D4B
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
The short-rooted phenotype of the brevis radix mutant partly reflects root abscisic acid hypersensitivity.
Périodique
Plant physiology
Auteur(s)
Rodrigues A., Santiago J., Rubio S., Saez A., Osmont K.S., Gadea J., Hardtke C.S., Rodriguez P.L.
ISSN
0032-0889
Statut éditorial
Publié
Date de publication
2009
Peer-reviewed
Oui
Volume
149
Numéro
4
Pages
1917-1928
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't - Publication Status: ppublish
Résumé
To gain further insight into abscisic acid (ABA) signaling and its role in growth regulation, we have screened for Arabidopsis (Arabidopsis thaliana) mutants hypersensitive to ABA-mediated root growth inhibition. As a result, we have identified a loss-of-function allele of BREVIS RADIX (BRX) in the Columbia background, named brx-2, which shows enhanced response to ABA-mediated inhibition of root growth. BRX encodes a key regulator of cell proliferation and elongation in the root, which has been implicated in the brassinosteroid (BR) pathway as well as in the regulation of auxin-responsive gene expression. Mutants affected in BR signaling that are not impaired in root growth, such as bes1-D, bzr1-D, and bsu1-D, also showed enhanced sensitivity to ABA-mediated inhibition of root growth. Triple loss-of-function mutants affected in PP2Cs, which act as negative regulators of ABA signaling, showed impaired root growth in the absence of exogenous ABA, indicating that disturbed regulation of ABA sensitivity impairs root growth. In agreement with this result, diminishing ABA sensitivity of brx-2 by crossing it with a 35S:HAB1 ABA-insensitive line allowed significantly higher recovery of root growth after brassinolide treatment. Finally, transcriptomic analysis revealed that ABA treatment negatively affects auxin signaling in wild-type and brx-2 roots and that ABA response is globally altered in brx-2. Taken together, our results reveal an interaction between BRs, auxin, and ABA in the control of root growth and indicate that altered sensitivity to ABA is partly responsible for the brx short-root phenotype.
Mots-clé
Abscisic Acid/pharmacology, Arabidopsis/drug effects, Arabidopsis/enzymology, Arabidopsis Proteins/genetics, Arabidopsis Proteins/metabolism, Cholestanols/pharmacology, Down-Regulation/drug effects, Gene Expression Profiling, Gene Expression Regulation, Plant/drug effects, Gene Knockout Techniques, Genes, Plant, Mutation/genetics, Nuclear Proteins/metabolism, Phenotype, Phosphoprotein Phosphatases/metabolism, Plant Roots/drug effects, Plant Roots/genetics, Steroids, Heterocyclic/pharmacology, Up-Regulation/drug effects
Pubmed
Web of science
Open Access
Oui
Création de la notice
07/07/2009 18:02
Dernière modification de la notice
09/05/2019 3:22
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