title: Plant development regulated by cytokinin sinks.
abstract: Morphogenetic signals control the patterning of multicellular organisms. Cytokinins are mobile signals that are perceived by subsets of plant cells. We found that the responses to cytokinin signaling during Arabidopsis development are constrained by the transporter PURINE PERMEASE 14 (PUP14). In our experiments, the expression of PUP14 was inversely correlated to the cytokinin signaling readout. Loss of PUP14 function allowed ectopic cytokinin signaling accompanied by aberrant morphogenesis in embryos, roots, and the shoot apical meristem. PUP14 protein localized to the plasma membrane and imported bioactive cytokinins, thus depleting apoplastic cytokinin pools and inhibiting perception by plasma membrane-localized cytokinin sensors to create a sink for active ligands. We propose that the spatiotemporal cytokinin sink patterns established by PUP14 determine the cytokinin signaling landscape that shapes the morphogenesis of land plants.
authors.affiliation: Zürich-Basel Plant Science Center, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Zürcher
authors.affiliation: Zürich-Basel Plant Science Center, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Plant Biology, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
authors.forename: Martin
authors.initials: M
authors.lastname: di Donato
authors.affiliation: Plant Biology, Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Geisler
authors.affiliation: Zürich-Basel Plant Science Center, Department of Plant and Microbial Biology, University of Zürich, 8008 Zürich, Switzerland. bruno.mueller@uzh.ch.
authors.forename: Bruno
authors.initials: B
authors.lastname: Müller
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000201:enzymology; D003583:Cytokinins / Q000378:metabolism*; D008024:Ligands; D018519:Meristem / Q000254:growth & development / Q000378:metabolism; D033702:Nucleobase Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003583:Cytokinins; D008024:Ligands; D033702:Nucleobase Transport Proteins; C000614901:purine permease 14, Arabidopsis; C022483:purine permease