title: Plasma membrane-targeted PIN proteins drive shoot development in a moss.
abstract: BACKGROUND
  Plant body plans arise by the activity of meristematic growing tips during development and radiated independently in the gametophyte (n) and sporophyte (2n) stages of the life cycle during evolution. Although auxin and its intercellular transport by PIN family efflux carriers are primary regulators of sporophytic shoot development in flowering plants, the extent of conservation in PIN function within the land plants and the mechanisms regulating bryophyte gametophytic shoot development are largely unknown.
  
  
  RESULTS
  We have found that treating gametophytic shoots of the moss Physcomitrella patens with exogenous auxins and auxin transport inhibitors disrupts apical function and leaf development. Two plasma membrane-targeted PIN proteins are expressed in leafy shoots, and pin mutants resemble plants treated with auxins or auxin transport inhibitors. PIN-mediated auxin transport regulates apical cell function, leaf initiation, leaf shape, and shoot tropisms in moss gametophytes. pin mutant sporophytes are sometimes branched, reproducing a phenotype only previously seen in the fossil record and in rare natural moss variants.
  
  
  CONCLUSIONS
  Our results show that PIN-mediated auxin transport is an ancient, conserved regulator of shoot development.
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK; Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge CB2 1LR, UK.
authors.forename: Tom A
authors.initials: TA
authors.lastname: Bennett
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Maureen M
authors.initials: MM
authors.lastname: Liu
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Aoyama
authors.affiliation: Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany.
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Bierfreund
authors.affiliation: Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Braun
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Yoan
authors.initials: Y
authors.lastname: Coudert
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Dennis
authors.affiliation: Sainsbury Laboratory, University of Cambridge, Bateman Street, Cambridge CB2 1LR, UK.
authors.forename: Devin
authors.initials: D
authors.lastname: O'Connor
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Xiao Y
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
authors.forename: Chris D
authors.initials: CD
authors.lastname: White
authors.affiliation: Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany.
authors.forename: Eva L
authors.initials: EL
authors.lastname: Decker
authors.affiliation: Faculty of Biology, University of Freiburg, Schänzlestraße 1, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, 79104 Freiburg, Germany; Freiburg Institute for Advanced Studies (FRIAS), 79104 Freiburg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Reski
authors.affiliation: Plant Sciences Department, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK. Electronic address: cjh97@cam.ac.uk.
authors.forename: C Jill
authors.initials: CJ
authors.lastname: Harrison
mesh_terms: D001692:Biological Transport / Q000187:drug effects; D044002:Bryophyta / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D055993:Germ Cells, Plant / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism / Q000494:pharmacology; D018519:Meristem / Q000187:drug effects / Q000378:metabolism; D009154:Mutation; D010797:Phthalimides / Q000494:pharmacology; D018515:Plant Leaves / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000254:growth & development / Q000378:metabolism*; D030821:Plants, Genetically Modified
chemical_list: D007210:Indoleacetic Acids; D010797:Phthalimides; D010940:Plant Proteins; C002687:alpha-naphthylphthalamic acid