title: Auxin regulates aquaporin function to facilitate lateral root emergence.
abstract: Aquaporins are membrane channels that facilitate water movement across cell membranes. In plants, aquaporins contribute to water relations. Here, we establish a new link between aquaporin-dependent tissue hydraulics and auxin-regulated root development in Arabidopsis thaliana. We report that most aquaporin genes are repressed during lateral root formation and by exogenous auxin treatment. Auxin reduces root hydraulic conductivity both at the cell and whole-organ levels. The highly expressed aquaporin PIP2;1 is progressively excluded from the site of the auxin response maximum in lateral root primordia (LRP) whilst being maintained at their base and underlying vascular tissues. Modelling predicts that the positive and negative perturbations of PIP2;1 expression alter water flow into LRP, thereby slowing lateral root emergence (LRE). Consistent with this mechanism, pip2;1 mutants and PIP2;1-overexpressing lines exhibit delayed LRE. We conclude that auxin promotes LRE by regulating the spatial and temporal distribution of aquaporin-dependent root tissue water transport.
authors.affiliation: Centre for Plant Integrative Biology, University of Nottingham, LE12 5RD, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Péret
authors.forename: Guowei
authors.initials: G
authors.lastname: Li
authors.forename: Jin
authors.initials: J
authors.lastname: Zhao
authors.forename: Leah R
authors.initials: LR
authors.lastname: Band
authors.forename: Ute
authors.initials: U
authors.lastname: Voß
authors.forename: Olivier
authors.initials: O
authors.lastname: Postaire
authors.forename: Doan-Trung
authors.initials: DT
authors.lastname: Luu
authors.forename: Olivier
authors.initials: O
authors.lastname: Da Ines
authors.forename: Ilda
authors.initials: I
authors.lastname: Casimiro
authors.forename: Mikaël
authors.initials: M
authors.lastname: Lucas
authors.forename: Darren M
authors.initials: DM
authors.lastname: Wells
authors.forename: Laure
authors.initials: L
authors.lastname: Lazzerini
authors.forename: Philippe
authors.initials: P
authors.lastname: Nacry
authors.forename: John R
authors.initials: JR
authors.lastname: King
authors.forename: Oliver E
authors.initials: OE
authors.lastname: Jensen
authors.forename: Anton R
authors.initials: AR
authors.lastname: Schäffner
authors.forename: Christophe
authors.initials: C
authors.lastname: Maurel
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Bennett
mesh_terms: D020346:Aquaporins / Q000235:genetics / Q000502:physiology*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000378:metabolism; D001692:Biological Transport / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D007210:Indoleacetic Acids / Q000378:metabolism*; D008954:Models, Biological; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development*; D014157:Transcription Factors / Q000378:metabolism; D014867:Water / Q000502:physiology
chemical_list: C503425:ARF7 protein, Arabidopsis; D020346:Aquaporins; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D014157:Transcription Factors; D014867:Water