title: Auxin depletion from leaf primordia contributes to organ patterning.
abstract: Stem cells are responsible for organogenesis, but it is largely unknown whether and how information from stem cells acts to direct organ patterning after organ primordia are formed. It has long been proposed that the stem cells at the plant shoot apex produce a signal, which promotes leaf adaxial-abaxial (dorsoventral) patterning. Here we show the existence of a transient low auxin zone in the adaxial domain of early leaf primordia. We also demonstrate that this adaxial low auxin domain contributes to leaf adaxial-abaxial patterning. The auxin signal is mediated by the auxin-responsive transcription factor MONOPTEROS (MP), whose constitutive activation in the adaxial domain promotes abaxial cell fate. Furthermore, we show that auxin flow from emerging leaf primordia to the shoot apical meristem establishes the low auxin zone, and that this auxin flow contributes to leaf polarity. Our results provide an explanation for the hypothetical meristem-derived leaf polarity signal. Opposite to the original proposal, instead of a signal derived from the meristem, we show that a signaling molecule is departing from the primordium to the meristem to promote robustness in leaf patterning.
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China;
authors.forename: Jiyan
authors.initials: J
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China; Howard Hughes Medical Institute and.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China; College of Agronomy, Northwest A&F University, Yangling, Shaanxi 712100, China; and.
authors.forename: Ting
authors.initials: T
authors.lastname: Yu
authors.affiliation: Center for Advanced Computing Research, Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA 91125;
authors.forename: Alexandre
authors.initials: A
authors.lastname: Cunha
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China;
authors.forename: Binbin
authors.initials: B
authors.lastname: Wu
authors.affiliation: Laboratoire de Reproduction et Développement des Plantes, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon I, Université de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France.
authors.forename: Teva
authors.initials: T
authors.lastname: Vernoux
authors.affiliation: Howard Hughes Medical Institute and Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125; meyerow@caltech.edu yljiao@genetics.ac.cn.
authors.forename: Elliot
authors.initials: E
authors.lastname: Meyerowitz
authors.affiliation: State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and National Center for Plant Gene Research, Beijing 100101, China; meyerow@caltech.edu yljiao@genetics.ac.cn.
authors.forename: Yuling
authors.initials: Y
authors.lastname: Jiao
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000196:embryology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism*; D063246:Organogenesis, Plant / Q000502:physiology*; D018515:Plant Leaves / Q000166:cytology / Q000201:enzymology*; D018520:Plant Shoots / Q000166:cytology / Q000196:embryology*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C111371:MONOPTEROS protein, Arabidopsis; D014157:Transcription Factors
keywords: auxin; leaf polarity; meristem; stem cell