title: Abscisic acid signaling is controlled by a BRANCHED1/HD-ZIP I cascade in Arabidopsis axillary buds.
abstract: Shoot-branching patterns determine key aspects of plant life and are important targets for crop breeding. However, we are still largely ignorant of the genetic networks controlling locally the most important decision during branch development: whether the axillary bud, or branch primordium, grows out to give a lateral shoot or remains dormant. Here we show that, inside the buds, the TEOSINTE BRANCHED1, CYCLOIDEA, PCF (TCP) transcription factor BRANCHED1 (BRC1) binds to and positively regulates the transcription of three related Homeodomain leucine zipper protein (HD-ZIP)-encoding genes: HOMEOBOX PROTEIN 21 (HB21), HOMEOBOX PROTEIN 40 (HB40), and HOMEOBOX PROTEIN 53 (HB53). These three genes, together with BRC1, enhance 9-CIS-EPOXICAROTENOID DIOXIGENASE 3 (NCED3) expression, lead to abscisic acid accumulation, and trigger hormone response, thus causing suppression of bud development. This TCP/HD-ZIP genetic module seems to be conserved in dicot and monocotyledonous species to prevent branching under light-limiting conditions.
authors.affiliation: Department of Plant Molecular Genetics, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Eduardo
authors.initials: E
authors.lastname: González-Grandío
authors.affiliation: Bioscience, Wageningen Plant Research, Wageningen University and Research, 6708 PB Wageningen, The Netherlands.|Laboratory of Molecular Biology, Wageningen University and Research, 6708 PB Wageningen, The Netherlands.
authors.forename: Alice
authors.initials: A
authors.lastname: Pajoro
authors.affiliation: Genomics Unit, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: José M
authors.initials: JM
authors.lastname: Franco-Zorrilla
authors.affiliation: Department of Plant Molecular Genetics, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Tarancón
authors.affiliation: Bioscience, Wageningen Plant Research, Wageningen University and Research, 6708 PB Wageningen, The Netherlands.
authors.forename: Richard G H
authors.initials: RG
authors.lastname: Immink
authors.affiliation: Department of Plant Molecular Genetics, Centro Nacional de Biotecnología/Consejo Superior de Investigaciones Científicas, Campus Universidad Autónoma de Madrid, 28049 Madrid, Spain; pcubas@cnb.csic.es.
authors.forename: Pilar
authors.identifier: 0000-0003-4679-2173
authors.initials: P
authors.lastname: Cubas
mesh_terms: D000040:Abscisic Acid / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D049308:Dioxygenases / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; C521259:BRC1 protein, Arabidopsis; C000606928:HB1 protein, Arabidopsis; D010940:Plant Proteins; D014157:Transcription Factors; D000040:Abscisic Acid; D049308:Dioxygenases; C109043:9-cis-epoxy-carotenoid dioxygenase
keywords: Arabidopsis; HD-ZIP proteins; TCP proteins; abscisic acid; bud dormancy