title: Inositol trisphosphate-induced Ca2+ signaling modulates auxin transport and PIN polarity.
abstract: The phytohormone auxin is an important determinant of plant development. Directional auxin flow within tissues depends on polar localization of PIN auxin transporters. To explore regulation of PIN-mediated auxin transport, we screened for suppressors of PIN1 overexpression (supo) and identified an inositol polyphosphate 1-phosphatase mutant (supo1), with elevated inositol trisphosphate (InsP(3)) and cytosolic Ca(2+) levels. Pharmacological and genetic increases in InsP(3) or Ca(2+) levels also suppressed the PIN1 gain-of-function phenotypes and caused defects in basal PIN localization, auxin transport and auxin-mediated development. In contrast, the reductions in InsP(3) levels and Ca(2+) signaling antagonized the effects of the supo1 mutation and disrupted preferentially apical PIN localization. InsP(3) and Ca(2+) are evolutionarily conserved second messengers involved in various cellular functions, particularly stress responses. Our findings implicate them as modifiers of cell polarity and polar auxin transport, and highlight a potential integration point through which Ca(2+) signaling-related stimuli could influence auxin-mediated development.
authors.affiliation: Department of Plant Systems Biology, VIB, Gent, Belgium.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.forename: Steffen
authors.initials: S
authors.lastname: Vanneste
authors.forename: Philip B
authors.initials: PB
authors.lastname: Brewer
authors.forename: Marta
authors.initials: M
authors.lastname: Michniewicz
authors.forename: Peter
authors.initials: P
authors.lastname: Grones
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kleine-Vehn
authors.forename: Christian
authors.initials: C
authors.lastname: Löfke
authors.forename: Thomas
authors.initials: T
authors.lastname: Teichmann
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bielach
authors.forename: Bernard
authors.initials: B
authors.lastname: Cannoot
authors.forename: Klára
authors.initials: K
authors.lastname: Hoyerová
authors.forename: Xu
authors.initials: X
authors.lastname: Chen
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Xue
authors.forename: Eva
authors.initials: E
authors.lastname: Benková
authors.forename: Eva
authors.initials: E
authors.lastname: Zažímalová
authors.forename: Jiří
authors.initials: J
authors.lastname: Friml
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D016764:Cell Polarity; D003600:Cytosol / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000378:metabolism; D050505:Mutant Proteins / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D050505:Mutant Proteins; C116363:PIN1 protein, Arabidopsis; D015544:Inositol 1,4,5-Trisphosphate; D010744:Phosphoric Monoester Hydrolases; C053087:inositol-1,4-bisphosphate 1-phosphatase; D002118:Calcium