title: Brassinosteroids Are Master Regulators of Gibberellin Biosynthesis in Arabidopsis.
abstract: Plant growth and development are highly regulated processes that are coordinated by hormones including the brassinosteroids (BRs), a group of steroids with structural similarity to steroid hormones of mammals. Although it is well understood how BRs are produced and how their signals are transduced, BR targets, which directly confer the hormone's growth-promoting effects, have remained largely elusive. Here, we show that BRs regulate the biosynthesis of gibberellins (GAs), another class of growth-promoting hormones, in Arabidopsis thaliana. We reveal that Arabidopsis mutants deficient in BR signaling are severely impaired in the production of bioactive GA, which is correlated with defective GA biosynthetic gene expression. Expression of the key GA biosynthesis gene GA20ox1 in the BR signaling mutant bri1-301 rescues many of its developmental defects. We provide evidence that supports a model in which the BR-regulated transcription factor BES1 binds to a regulatory element in promoters of GA biosynthesis genes in a BR-induced manner to control their expression. In summary, our study underscores a role of BRs as master regulators of GA biosynthesis and shows that this function is of major relevance for the growth and development of vascular plants.
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Unterholzner
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Wilfried
authors.initials: W
authors.lastname: Rozhon
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Michael
authors.identifier: http://orcid.org/0000-0001-9669-9319
authors.initials: M
authors.lastname: Papacek
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ciomas
authors.affiliation: Institute of Plant Biology, Technical University of Braunschweig, D-38106 Braunschweig, Germany.
authors.forename: Theo
authors.identifier: http://orcid.org/0000-0003-1294-2647
authors.initials: T
authors.lastname: Lange
authors.affiliation: Plant Genome and System Biology, Helmholtz Center Munich, D-85764 Neuherberg, Germany.
authors.forename: Karl G
authors.identifier: http://orcid.org/0000-0003-2342-7472
authors.initials: KG
authors.lastname: Kugler
authors.affiliation: Plant Genome and System Biology, Helmholtz Center Munich, D-85764 Neuherberg, Germany.
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Mayer
authors.affiliation: Plant Growth Regulation, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Sieberer
authors.affiliation: Biotechnology of Horticultural Crops, TUM School of Life Sciences Weihenstephan, Technische Universität München, D-85354 Freising, Germany brigitte.poppenberger@wzw.tum.de.
authors.forename: Brigitte
authors.identifier: http://orcid.org/0000-0003-1020-0500
authors.initials: B
authors.lastname: Poppenberger
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D004268:DNA-Binding Proteins; D035264:Flowers / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000096:biosynthesis* / Q000494:pharmacology; D018546:Hypocotyl / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015151:Immunoblotting; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism / Q000494:pharmacology; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C456160:BES1 protein, Arabidopsis; D060406:Brassinosteroids; D004268:DNA-Binding Proteins; D005875:Gibberellins; D009687:Nuclear Proteins; D010937:Plant Growth Regulators; D006899:Mixed Function Oxygenases; C000606235:gibberellin 20 oxidase 1, Arabidopsis; D011494:Protein Kinases; C108270:BRI1 protein, Arabidopsis