Cytokinin signalling regulates organ identity via the AHK4 receptor in Arabidopsis

0493505 - ÚEB 2019 RIV GB eng J - Journal Article
Pernisová, M. - Grochová, M. - Konečný, T. - Plačková, Lenka - Haruštiaková, D. - Kakimoto, T. - Heisler, M. - Novák, Ondřej - Hejátko, J.
Cytokinin signalling regulates organ identity via the AHK4 receptor in Arabidopsis.
Development. Roč. 145, č. 14 (2018), č. článku dev163907. ISSN 0950-1991. E-ISSN 1477-9129
R&D Projects: GA MŠMT(CZ) LQ1601; GA MŠMT(CZ) LO1204; GA MŠMT(CZ) LM2015062
Institutional support: RVO:61389030
Keywords : lateral root primordia * to-asp phosphorelay * shoot meristem * response regulators * cell-differentiation * transcription factor * beta-glucosidase * tissue-culture * auxin efflux * stem-cells * Arabidopsis * Cytokinin metabolism * Cytokinin signalling * De novo organogenesis * Root * Shoot
OECD category: Developmental biology
Impact factor: 5.763, year: 2018

Mutual interactions of the phytohormones, cytokinins and auxin determine root or shoot identity during postembryonic de novo organogenesis in plants. However, our understanding of the role of hormonal metabolism and perception during early stages of cell fate reprogramming is still elusive. Here we show that auxin activates root formation, whereas cytokinins mediate early loss of the root identity, primordia disorganisation and initiation of shoot development. Exogenous and endogenous cytokinins influence the initiation of newly formed organs, as well as the pace of organ development. The process of de novo shoot apical meristem establishment is accompanied by accumulation of endogenous cytokinins, differential regulation of genes for individual cytokinin receptors, strong activation of AHK4-mediated signalling and induction of the shoot-specific homeodomain regulator WUSCHEL. The last is associated with upregulation of isopentenyladenine-type cytokinins, revealing higher shoot-forming potential when compared with trans-zeatin. Moreover, AHK4-controlled cytokinin signalling negatively regulates the root stem cell organiser WUSCHEL RELATED HOMEOBOX 5 in the root quiescent centre. We propose an important role for endogenous cytokinin biosynthesis and AHK4-mediated cytokinin signalling in the control of de novo-induced organ identity.
Permanent Link: http://hdl.handle.net/11104/0286864