A non-DNA-binding activity for the ATHB4 transcription factor in the control of vegetation proximity
Gallemí, Marçal (Centre de Recerca en Agrigenòmica)
Molina-Contreras, Maria Jose (Centre de Recerca en Agrigenòmica)
Paulišić, Sandi (Centre de Recerca en Agrigenòmica)
Salla-Martret, Mercè (Centre de Recerca en Agrigenòmica)
Sorin, Céline (Centre de Recerca en Agrigenòmica)
Godoy, Marta (Centro Nacional de Biotecnología (Espanya))
Franco-Zorrilla, Jose Manuel (Centro Nacional de Biotecnología (Espanya))
Solano, Roberto (Centro Nacional de Biotecnología (Espanya))
Martínez García, Jaime F. (Centre de Recerca en Agrigenòmica)

Date:	2017
Abstract:	In plants, perception of vegetation proximity by phytochrome photoreceptors activates a transcriptional network that implements a set of responses to adapt to plant competition, including elongation of stems or hypocotyls. In Arabidopsis thaliana, the homeodomain-leucine zipper (HD-Zip) transcription factor ARABIDOPSIS THALIANA HOMEOBOX 4 (ATHB4) regulates this and other responses, such as leaf polarity. To better understand the shade regulatory transcriptional network, we have carried out structure-function analyses of ATHB4 by overexpressing a series of truncated and mutated forms and analyzing three different responses: hypocotyl response to shade, transcriptional activity and leaf polarity. Our results indicated that ATHB4 has two physically separated molecular activities: that performed by HD-Zip, which is involved in binding to DNA-regulatory elements, and that performed by the ETHYLENE-RESPONSIVE ELEMENT BINDING FACTOR-associated amphiphilic repression (EAR)-containing N-terminal region, which is involved in protein-protein interaction. Whereas both activities are required to regulate leaf polarity, DNA-binding activity is not required for the regulation of the seedling responses to plant proximity, which indicates that ATHB4 works as a transcriptional cofactor in the regulation of this response. These findings suggest that transcription factors might employ alternative mechanisms of action to regulate different developmental processes.
Grants:	Ministerio de Economía y Competitividad SEV-2015-0533 Ministerio de Economía y Competitividad BIO2014-59895-P Ministerio de Economía y Competitividad BIO2011-23489 Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-447
Note:	Altres ajuts: Generalitat de Catalunya through the CERCA Program
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Arabidopsis thaliana ; Arabidopsis thaliana homeobox 4 (ATHB4) ; DNA-binding activity ; Ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motif ; Homeodomain-leucine zipper ; Shade avoidance syndrome
Published in:	The new phytologist, Vol. 216, issue 3 (Nov. 2017) , p. 798-813, ISSN 1469-8137

DOI: 10.1111/nph.14727

Post-print. Article 41 p, 15.2 MB

Post-print. Supplementary material 29 p, 2.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CRAG (Centre for Research in Agricultural Genomics)
Articles > Research articles
Articles > Published articles