title: Regulation of MIR165/166 by class II and class III homeodomain leucine zipper proteins establishes leaf polarity.
abstract: A defining feature of plant leaves is their flattened shape. This shape depends on an antagonism between the genes that specify adaxial (top) and abaxial (bottom) tissue identity; however, the molecular nature of this antagonism remains poorly understood. Class III homeodomain leucine zipper (HD-ZIP) transcription factors are key mediators in the regulation of adaxial-abaxial patterning. Their expression is restricted adaxially during early development by the abaxially expressed microRNA (MIR)165/166, yet the mechanism that restricts MIR165/166 expression to abaxial leaf tissues remains unknown. Here, we show that class III and class II HD-ZIP proteins act together to repress MIR165/166 via a conserved cis-element in their promoters. Organ morphology and tissue patterning in plants, therefore, depend on a bidirectional repressive circuit involving a set of miRNAs and its targets.
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
authors.forename: Paz
authors.initials: P
authors.lastname: Merelo
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
authors.forename: Hathi
authors.initials: H
authors.lastname: Ram
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
authors.forename: Monica
authors.initials: M
authors.lastname: Pia Caggiano
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
authors.forename: Carolyn
authors.initials: C
authors.lastname: Ohno
authors.affiliation: Department of Molecular Biology, Max Planck Institute for Developmental Biology, 72076 Tubingen, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Ott
authors.affiliation: Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark; Centre for Plant Molecular Biology, University of Tübingen, 72076 Tubingen, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Straub
authors.affiliation: Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark; Centre for Plant Molecular Biology, University of Tübingen, 72076 Tubingen, Germany.
authors.forename: Moritz
authors.initials: M
authors.lastname: Graeff
authors.affiliation: Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark; Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, 120-749 Seodaemoon-gu, Yonsei-ro 50, Seoul, Korea.
authors.forename: Seok Keun
authors.initials: SK
authors.lastname: Cho
authors.affiliation: Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark; Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, 120-749 Seodaemoon-gu, Yonsei-ro 50, Seoul, Korea.
authors.forename: Seong Wook
authors.initials: SW
authors.lastname: Yang
authors.affiliation: Department of Plant and Environmental Sciences, Copenhagen Plant Science Centre, University of Copenhagen, 1871 Frederiksberg C, Denmark; Centre for Plant Molecular Biology, University of Tübingen, 72076 Tubingen, Germany; heisler@embl.de wenkel@plen.ku.dk.
authors.forename: Stephan
authors.initials: S
authors.lastname: Wenkel
authors.affiliation: Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany; School of Biological Sciences, University of Sydney, Sydney, NSW 2006, Australia heisler@embl.de wenkel@plen.ku.dk.
authors.forename: Marcus G
authors.initials: MG
authors.lastname: Heisler
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics; D015415:Biomarkers; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D016350:Leucine Zippers / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*; D008954:Models, Biological; D063245:Plant Development / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics*; D011485:Protein Binding; D019655:Quantitative Trait, Heritable; D020218:Response Elements
chemical_list: D029681:Arabidopsis Proteins; D015415:Biomarkers; D018398:Homeodomain Proteins; D035683:MicroRNAs
keywords: MIR165/166; class II HD-ZIP; class III HD-ZIP; leaf morphogenesis; organ patterning