title: Role of PIN-mediated auxin efflux in apical hook development of Arabidopsis thaliana.
abstract: The apical hook of dark-grown Arabidopsis seedlings is a simple structure that develops soon after germination to protect the meristem tissues during emergence through the soil and that opens upon exposure to light. Differential growth at the apical hook proceeds in three sequential steps that are regulated by multiple hormones, principally auxin and ethylene. We show that the progress of the apical hook through these developmental phases depends on the dynamic, asymmetric distribution of auxin, which is regulated by auxin efflux carriers of the PIN family. Several PIN proteins exhibited specific, partially overlapping spatial and temporal expression patterns, and their subcellular localization suggested auxin fluxes during hook development. Genetic manipulation of individual PIN activities interfered with different stages of hook development, implying that specific combinations of PIN genes are required for progress of the apical hook through the developmental phases. Furthermore, ethylene might modulate apical hook development by prolonging the formation phase and strongly suppressing the maintenance phase. This ethylene effect is in part mediated by regulation of PIN-dependent auxin efflux and auxin signaling.
authors.affiliation: Department of Plant Systems Biology, Flanders Institute for Biotechnology (VIB) and Department of Plant Biotechnology and Genetics, Ghent University, Gent, Belgium.
authors.forename: Petra
authors.initials: P
authors.lastname: Zádníková
authors.forename: Jan
authors.initials: J
authors.lastname: Petrásek
authors.forename: Peter
authors.initials: P
authors.lastname: Marhavy
authors.forename: Vered
authors.initials: V
authors.lastname: Raz
authors.forename: Filip
authors.initials: F
authors.lastname: Vandenbussche
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Ding
authors.forename: Katerina
authors.initials: K
authors.lastname: Schwarzerová
authors.forename: Miyo T
authors.initials: MT
authors.lastname: Morita
authors.forename: Masao
authors.initials: M
authors.lastname: Tasaka
authors.forename: Jan
authors.initials: J
authors.lastname: Hejátko
authors.forename: Dominique
authors.initials: D
authors.lastname: Van Der Straeten
authors.forename: Jirí
authors.initials: J
authors.lastname: Friml
authors.forename: Eva
authors.initials: E
authors.lastname: Benková
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005030:Ethylenes / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D018519:Meristem / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D030821:Plants, Genetically Modified; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D005030:Ethylenes; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; C449300:PIN3 protein, Arabidopsis; C451260:PIN4 protein, Arabidopsis; C479554:PIN7 protein, Arabidopsis; D011993:Recombinant Fusion Proteins; C036216:ethylene