Cytokinin controls polarity of PIN1-dependent Auxin transport during lateral root organogenesis Journal Article

Author(s): Marhavý, Peter; Duclercq, Jérôme; Weller, Benjamin; Feraru, Elena; Bielach, Agnieszka; Offringa, Remko; Friml, Jiří; Schwechheimer, Claus; Murphy, Angus S; Benková, Eva
Article Title: Cytokinin controls polarity of PIN1-dependent Auxin transport during lateral root organogenesis
Affiliation IST Austria
Abstract: The plant hormones auxin and cytokinin mutually coordinate their activities to control various aspects of development [1-9], and their crosstalk occurs at multiple levels [10, 11]. Cytokinin-mediated modulation of auxin transport provides an efficient means to regulate auxin distribution in plant organs. Here, we demonstrate that cytokinin does not merely control the overall auxin flow capacity, but might also act as a polarizing cue and control the auxin stream directionality during plant organogenesis. Cytokinin enhances the PIN-FORMED1 (PIN1) auxin transporter depletion at specific polar domains, thus rearranging the cellular PIN polarities and directly regulating the auxin flow direction. This selective cytokinin sensitivity correlates with the PIN protein phosphorylation degree. PIN1 phosphomimicking mutations, as well as enhanced phosphorylation in plants with modulated activities of PIN-specific kinases and phosphatases, desensitize PIN1 to cytokinin. Our results reveal conceptually novel, cytokinin-driven polarization mechanism that operates in developmental processes involving rapid auxin stream redirection, such as lateral root organogenesis, in which a gradual PIN polarity switch defines the growth axis of the newly formed organ.
Journal Title: Current Biology
Volume: 24
Issue 9
ISSN: 0960-9822
Publisher: Cell Press  
Date Published: 2014-05-05
Start Page: 1031
End Page: 1037
Sponsor: This work was supported by a European Research Council Starting Independent Research Grant (ERC-2007-Stg-207362-HCPO to E.B.), the Division of Energy Biosciences, US Department of Energy (grant DE-FG02-06ER15804 to A.S.M.), and an EMBO for a postdoctoral
DOI: 10.1016/j.cub.2014.04.002
Notes: We thank Candela Cuesta for technical assistance, Doron Scolnik for sharing expression and imaging results prior to publication, Jürgen Kleine-Vehn for discussions and critical reading of the manuscript, and Annick Bleys and Martine De Cock for help in preparing it.
Open access: no