Light Controls Cytokinin Signaling via Transcriptional Regulation of Constitutively Active Sensor Histidine Kinase CKI1

Investor logo
Investor logo
Investor logo

Warning

This publication doesn't include Faculty of Arts. It includes Central European Institute of Technology. Official publication website can be found on muni.cz.
Authors

DOBISOVÁ Tereza HRDINOVÁ Vendula CUESTA Candela MICHLÍČKOVÁ Šárka URBÁNKOVÁ Ivana HEJÁTKOVÁ Romana ŽÁDNÍKOVÁ Petra PERNISOVÁ Markéta BENKOVÁ Eva HEJÁTKO Jan

Year of publication 2017
Type Article in Periodical
Magazine / Source Plant Physiology
MU Faculty or unit

Central European Institute of Technology

Citation
Web https://academic.oup.com/plphys/article/174/1/387/6116747
Doi http://dx.doi.org/10.1104/pp.16.01964
Field Genetics and molecular biology
Keywords light; cytokinin; signalling; CKI1
Description In plants, the multistep phosphorelay (MSP) pathway mediates a range of regulatory processes, including those activated by cytokinins. The crosstalk between cytokinin response and light is known for a long time. However, the molecular mechanism underlying the interaction between light and cytokinin signaling remains elusive. In the screen for upstream regulators we identified a LONG PALE HYPOCOTYL (LPH) gene whose activity is indispensable for spatiotemporally correct expression of CYTOKININ INDEPENDENT-1 (CKI1), encoding the constitutively active sensor histidine kinase that activates MSP signaling. lph is a new allele of HEME OXYGENASE 1 (HY1) which encodes the key protein in the biosynthesis of phytochromobilin, a cofactor of photoconvertible phytochromes. Our analysis confirmed the light-dependent regulation of the CKI1 expression pattern. We show that CKI1 expression is under the control of phytochrome A (phyA), functioning as a dual (both positive and negative) regulator of CKI1 expression, presumably via the phyA-regulated transcription factors PHYTOCHROME INTERACTING FACTOR 3 (PIF3) and CIRCADIAN CLOCK ASSOCIATED 1 (CCA1). Changes in CKI1 expression observed in lph/hy1-7 and phy mutants correlate with misregulation of MSP signaling, changed cytokinin sensitivity and developmental aberrations, previously shown to be associated with cytokinin and/or CKI1 action. Besides that, we demonstrate novel role of phyA-dependent CKI1 expression in the hypocotyl elongation and hook development during skotomorphogenesis. Based on these results, we propose that the light-dependent regulation of CKI1 provides a plausible mechanistic link underlying the well-known interaction between light- and cytokinin controlled plant development.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.