title: Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development.
abstract: The signalling molecule auxin controls plant morphogenesis via its activity gradients, which are produced by intercellular auxin transport. Cellular auxin efflux is the rate-limiting step in this process and depends on PIN and phosphoglycoprotein (PGP) auxin transporters. Mutual roles for these proteins in auxin transport are unclear, as is the significance of their interactions for plant development. Here, we have analysed the importance of the functional interaction between PIN- and PGP-dependent auxin transport in development. We show by analysis of inducible overexpression lines that PINs and PGPs define distinct auxin transport mechanisms: both mediate auxin efflux but they play diverse developmental roles. Components of both systems are expressed during embryogenesis, organogenesis and tropisms, and they interact genetically in both synergistic and antagonistic fashions. A concerted action of PIN- and PGP-dependent efflux systems is required for asymmetric auxin distribution during these processes. We propose a model in which PGP-mediated efflux controls auxin levels in auxin channel-forming cells and, thus, auxin availability for PIN-dependent vectorial auxin movement.
authors.affiliation: Department of Plant Systems Biology, VIB, Ghent University, 9052 Gent, Belgium.
authors.forename: Jozef
authors.initials: J
authors.lastname: Mravec
authors.forename: Martin
authors.initials: M
authors.lastname: Kubes
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Bielach
authors.forename: Vassilena
authors.initials: V
authors.lastname: Gaykova
authors.forename: Jan
authors.initials: J
authors.lastname: Petrásek
authors.forename: Petr
authors.initials: P
authors.lastname: Skůpa
authors.forename: Suresh
authors.initials: S
authors.lastname: Chand
authors.forename: Eva
authors.initials: E
authors.lastname: Benková
authors.forename: Eva
authors.initials: E
authors.lastname: Zazímalová
authors.forename: Jirí
authors.initials: J
authors.lastname: Friml
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D008954:Models, Biological; D018521:Plant Physiological Phenomena
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis