Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX

Tesis doctoral del Departamento de Biotecnología de la Universidad Politécnica de Valencia, realizada en el Instituto de Biología Molecular y Celular de Plantas

Detalles Bibliográficos
Autor: Rodrigues, Americo do Patrocinio
Tipo de recurso: tesis doctoral
Fecha de publicación:2009
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/18827
Acceso en línea:http://hdl.handle.net/10261/18827
Access Level:acceso abierto
Palabra clave:Ácido abscísico
Brasinoesteroides
Arabidopsis
HAB1
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oai_identifier_str oai:digital.csic.es:10261/18827
network_acronym_str ES
network_name_str España
repository_id_str
dc.title.none.fl_str_mv Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
title Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
spellingShingle Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
Rodrigues, Americo do Patrocinio
Ácido abscísico
Brasinoesteroides
Arabidopsis
HAB1
title_short Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
title_full Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
title_fullStr Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
title_full_unstemmed Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
title_sort Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRX
dc.creator.none.fl_str_mv Rodrigues, Americo do Patrocinio
author Rodrigues, Americo do Patrocinio
author_facet Rodrigues, Americo do Patrocinio
author_role author
dc.contributor.none.fl_str_mv Rodriguez Egea, Pedro
dc.subject.none.fl_str_mv Ácido abscísico
Brasinoesteroides
Arabidopsis
HAB1
topic Ácido abscísico
Brasinoesteroides
Arabidopsis
HAB1
description Tesis doctoral del Departamento de Biotecnología de la Universidad Politécnica de Valencia, realizada en el Instituto de Biología Molecular y Celular de Plantas
publishDate 2009
dc.date.none.fl_str_mv 2009
2009
2009
dc.type.none.fl_str_mv info:eu-repo/semantics/doctoralThesis
http://purl.org/coar/resource_type/c_db06
format doctoralThesis
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/18827
url http://hdl.handle.net/10261/18827
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv 8126056 bytes
application/pdf
dc.publisher.none.fl_str_mv Universidad Politécnica de Valencia
publisher.none.fl_str_mv Universidad Politécnica de Valencia
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
_version_ 1869421787184365568
spelling Abscisic acid signal transduction: Regulation by HAB1 and interaction with brassinosteroids mediated by BRXRodrigues, Americo do PatrocinioÁcido abscísicoBrasinoesteroidesArabidopsisHAB1Tesis doctoral del Departamento de Biotecnología de la Universidad Politécnica de Valencia, realizada en el Instituto de Biología Molecular y Celular de PlantasThe phytohormone abscisic acid (ABA) is a key regulator of plant growth and development as well as of plant responses to stress namely water and salt stresses. To gain further insight into ABA signaling and its role in growth regulation, we have screened for Arabidopsis thaliana mutants hypersensitive to ABA-mediated root growth inhibition. In this screen, we have identified a loss-of-function allele of BREVIS RADIX (BRX) in Columbia background, named brx-2. 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 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 protein phosphatases type-2C (PP2Cs) that 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 ABAinsensitive line allowed significantly higher recovery of root growth after BL 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 fine tuning of ABA response might be required to prevent a deleterious effect on growth and development in the absence of environmental stress. ABA response is controlled by a complex network in which phosphorylation/dephosphorylation events have a very important role. HAB1 is a PP2C that plays a key role as negative regulator of ABA signaling; however, the molecular details of HAB1 action in this process are not known. A two hybrid screening revealed that AtSWI3B, an Arabidopsis homolog of the yeast SWI3 subunit of SWI/SNF chromatin remodeling complexes, is a prevalent interacting partner of HAB1. The interaction mapped to the N-terminal half of AtSWI3B and required an intact protein phosphatase catalytic domain. Bimolecular fluorescence complementation (BiFC) and coimmunoprecipitation (ChIP) assays confirmed the interaction of HAB1 and SWI3B in the nucleus of plant cells. Yeast two hybrid and BiFC assays also confirmed the interaction of SWI3B with ABI1, ABI2 and PP2CA, though this interaction was weaker than the observed with HAB1. swi3b mutants showed a reduced sensitivity to ABA mediated inhibition of seed germination and growth, and reduced expression of the ABA-responsive genes RAB18 and RD29B. ChIP experiments showed that the presence of HAB1 in the vicinity of RD29B and RAB18 promoters was abolished by ABA, which suggests a direct involvement of HAB1 in regulation of ABA-induced transcription. Contrary to the phenotypes presented by swi3b mutants, mutants of BRM and SYD, other putative members of Arabidopsis SWI/SNF complex, showed hypersensitivity to ABA in germination, root growth and enhanced expression of ABA responsive genes. Additionally, our results uncover AtSWI3B as a novel positive regulator of ABA signaling and suggest that HAB1 modulates ABA response through regulation of a putative SWI/SNF chromatin remodelling complex.Peer reviewedUniversidad Politécnica de ValenciaRodriguez Egea, Pedro200920092009info:eu-repo/semantics/doctoralThesishttp://purl.org/coar/resource_type/c_db068126056 bytesapplication/pdfhttp://hdl.handle.net/10261/18827reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglésinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/188272026-05-22T06:33:51Z
score 15.812429

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