TOPLESS mediates brassinosteroid control of shoot boundaries and root meristem development inArabidopsis thaliana.
The transcription factor BRI1-EMS-SUPRESSOR 1 (BES1) is a master regulator of brassinosteroid (BR)-regulated gene expression. BES1 together with BRASSINAZOLE-RESISTANT 1 (BZR1) drive activated or repressed expression of several genes, and have a prominent role in negative regulation of BR synthesis. Here, we report that BES1 interaction with TOPLESS (TPL), via its ERF-associated amphiphilic repression (EAR) motif, is essential for BES1-mediated control of organ boundary formation in the shoot apical meristem and the regulation of quiescent center (QC) cell division in roots. We show that TPL binds via BES1 to the promoters of theCUC3andBRAVOtargets and suppresses their expression. Ectopic expression of TPL leads to similar organ boundary defects and alterations in QC cell division rate to thebes1-dmutation, whilebes1-ddefects are suppressed by the dominant interfering protein encoded bytpl-1, with these effects respectively correlating with changes inCUC3andBRAVOexpression. Together, our data unveil a pivotal role of the co-repressor TPL in the shoot and root meristems, which relies on its interaction with BES1 and regulation of BES1 target gene expression.
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid E-28049, Spain.
Ana
A
Espinosa-Ruiz
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid E-28049, Spain.
Cristina
C
Martínez
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid E-28049, Spain.
Miguel
M
de Lucas
Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona E-08193, Spain.
Norma
N
Fàbregas
Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona E-08193, Spain.
Nadja
N
Bosch
Department of Molecular Genetics, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Barcelona E-08193, Spain.
Ana I
AI
Caño-Delgado
Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Darwin 3, Madrid E-28049, Spain sprat@cnb.csic.es.
Salomé
0000-0003-2684-5485
S
Prat
D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D060406:Brassinosteroids / Q000378:metabolism*; D002455:Cell Division; D035264:Flowers / Q000502:physiology; D018628:Gene Dosage; D018506:Gene Expression Regulation, Plant; D018519:Meristem / Q000196:embryology* / Q000378:metabolism*; D038081:Organogenesis; D010641:Phenotype; D018515:Plant Leaves / Q000196:embryology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D014158:Transcription, Genetic
D029681:Arabidopsis Proteins; D060406:Brassinosteroids; C511291:At1g15750 protein, Arabidopsis
BES1; BR signaling; EAR domain; Organ boundary; Quiescence; Quiescent center; TOPLESS