Interaction of PIN and PGP transport mechanisms in auxin distribution-dependent development.
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.
Mravec
Jozef
J
Department of Plant Systems Biology, VIB, Ghent University, 9052 Gent, Belgium.
Kubes
Martin
M
Bielach
Agnieszka
A
Gaykova
Vassilena
V
Petrásek
Jan
J
Skůpa
Petr
P
Chand
Suresh
S
Benková
Eva
E
Zazímalová
Eva
E
Friml
Jirí
J
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
D018435:ATP Binding Cassette Transporter, Subfamily B; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis