title: Auxin triggers transient local signaling for cell specification in Arabidopsis embryogenesis.
abstract: The Arabidopsis embryonic root meristem is initiated by the specification of a single cell, the hypophysis. This event critically requires the antagonistic auxin response regulators MONOPTEROS and BODENLOS, but their mechanism of action is unknown. We show that these proteins interact and transiently act in a small subdomain of the proembryo adjacent to the future hypophysis. Here they promote transport of auxin, which then elicits a second response in the hypophysis itself. Our results suggest that hypophysis specification is not the direct result of a primary auxin response but rather depends on cell-to-cell signaling triggered by auxin in adjacent cells.
authors.affiliation: ZMBP Entwicklungsgenetik, Universität Tübingen, Auf der Morgenstelle 3, D-72076 Tübingen, Germany.
authors.forename: Dolf
authors.initials: D
authors.lastname: Weijers
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schlereth
authors.forename: Jasmin S
authors.initials: JS
authors.lastname: Ehrismann
authors.forename: Gerald
authors.initials: G
authors.lastname: Schwank
authors.forename: Marika
authors.initials: M
authors.lastname: Kientz
authors.forename: Gerd
authors.initials: G
authors.lastname: Jürgens
mesh_terms: D017360:Arabidopsis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D001693:Biological Transport, Active; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D018519:Meristem / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D018517:Plant Roots / Q000196:embryology / Q000378:metabolism; D030821:Plants, Genetically Modified; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C111371:MONOPTEROS protein, Arabidopsis; D014157:Transcription Factors