title: Arabidopsis NAC transcription factor JUB1 regulates GA/BR metabolism and signalling.
abstract: Gibberellins (GAs) and brassinosteroids (BRs) are important phytohormones that control plant development and responses to environmental cues by involving DELLA proteins and BRASSINAZOLE-RESISTANT1 (BZR1) respectively as key transcription factors. Here, we reveal a new role for JUNGBRUNNEN1 (JUB1) as a transcriptional regulator of GA/BR signalling in Arabidopsis thaliana. JUB1 directly represses the hormone biosynthesis genes GA3ox1 and DWARF4 (DWF4), leading to reduced levels of GAs and BRs and typical GA/BR deficiency phenotypes exhibiting short hypocotyls, dwarfism, late flowering and male sterility. JUB1 also directly represses PHYTOCHROME INTERACTING FACTOR4 (PIF4), a transcription factor connecting hormonal and environmental stimuli. On the other hand, JUB1 activates the DELLA genes GA INSENSITIVE (GAI) and RGA-LIKE 1 (RGL1). In addition, BZR1 and PIF4 act as direct transcriptional repressors upstream of JUB1, establishing a negative feedback loop. Thus, JUB1 forms the core of a robust regulatory module that triggers DELLA accumulation, thereby restricting cell elongation while concomitantly enhancing stress tolerance.
authors.affiliation: University of Potsdam, Institute of Biochemistry and Biology, Karl-Liebknecht-Straße 24-25, Haus 20, 14476 Potsdam-Golm, Germany.|Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
authors.forename: Sara
authors.initials: S
authors.lastname: Shahnejat-Bushehri
authors.affiliation: Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany ASCR and Palacky University, v.v.i. Slechtitelu 11, CZ-783 71 Olomouc, Czech Republic.
authors.forename: Danuse
authors.initials: D
authors.lastname: Tarkowska
authors.affiliation: Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Sakuraba
authors.affiliation: University of Potsdam, Institute of Biochemistry and Biology, Karl-Liebknecht-Straße 24-25, Haus 20, 14476 Potsdam-Golm, Germany.|Max-Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, 14476 Potsdam-Golm, Germany.
authors.forename: Salma
authors.initials: S
authors.lastname: Balazadeh
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005875:Gibberellins / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D063245:Plant Development / Q000235:genetics; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D015398:Signal Transduction; D013312:Stress, Physiological / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: C588250:ANAC042 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060406:Brassinosteroids; D005875:Gibberellins; D014157:Transcription Factors