title: Auxin-regulated chromatin switch directs acquisition of flower primordium founder fate.
abstract: Reprogramming of cell identities during development frequently requires changes in the chromatin state that need to be restricted to the correct cell populations. Here we identify an auxin hormone-regulated chromatin state switch that directs reprogramming from transit amplifying to primordium founder cell fate in Arabidopsis inflorescences. Upon auxin sensing, the MONOPTEROS transcription factor recruits SWI/SNF chromatin remodeling ATPases to increase accessibility of the DNA for induction of key regulators of flower primordium initiation. In the absence of the hormonal cue, auxin sensitive Aux/IAA proteins bound to MONOPTEROS block recruitment of the SWI/SNF chromatin remodeling ATPases in addition to recruiting a co-repressor/histone deacetylase complex. This simple and elegant hormone-mediated chromatin state switch is ideally suited for iterative flower primordium initiation and orchestrates additional auxin-regulated cell fate transitions. Our findings establish a new paradigm for nuclear response to auxin. They also provide an explanation for how this small molecule can direct diverse plant responses.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, United States.
authors.forename: Miin-Feng
authors.initials: MF
authors.lastname: Wu
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, United States.
authors.forename: Nobutoshi
authors.initials: N
authors.lastname: Yamaguchi
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States.
authors.forename: Bastiaan
authors.initials: B
authors.lastname: Bargmann
authors.affiliation: Section of Cell and Developmental Biology, Howard Hughes Medical Institute, University of California, San Diego, San Diego, United States.
authors.forename: Mark
authors.initials: M
authors.lastname: Estelle
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, United States.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sang
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, United States.
authors.forename: Doris
authors.initials: D
authors.lastname: Wagner
mesh_terms: D017360:Arabidopsis / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism; D002843:Chromatin / Q000187:drug effects* / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D035264:Flowers / Q000254:growth & development*; D007210:Indoleacetic Acids / Q000378:metabolism*; D008954:Models, Biological; D010937:Plant Growth Regulators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D007210:Indoleacetic Acids; C111371:MONOPTEROS protein, Arabidopsis; D010937:Plant Growth Regulators; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors
keywords: Arabidopsis thaliana; Aux/IAA; arabidopsis; auxin response; auxin response factor 5/MONOPTEROS; chromatin remodeling; flower primordium initiation; plant biology