PCH1 integrates circadian and light- signaling pathways to control photoperiod-responsive growth in Arabidopsis

Authors

He Huang, Donald Danforth Plant Science Center
Chan Yul Yoo, University of California at Riverside
Rebecca Bindbeutel, Donald Danforth Plant Science Center
Jessica Goldsworthy, Michigan State University
Allison Tielking, Mary Institute and Saint Louis Country Day School
Sophie Alvarez, University of Nebraska-LincolnFollow
Michael J. Naldrett, University of Nebraska - LincolnFollow
Bradley S. Evans, Donald Danforth Plant Science CenterFollow
Meng Chen, University of California at Riverside
Dmitri A. Nusinow, Donald Danforth Plant Science CenterFollow

Date of this Version

2016

Document Type

Article

Citation

eLife 2016;5:e13292

Comments

Copyright Huang et al.

Open access

DOI: 10.7554/eLife.13292

Abstract

Plants react to seasonal change in day length through altering physiology and development. Factors that function to harmonize growth with photoperiod are poorly understood. Here we characterize a new protein that associates with both circadian clock and photoreceptor components, named PHOTOPERIODIC CONTROL OF HYPOCOTYL1 (PCH1). pch1 seedlings have overly elongated hypocotyls specifically under short days while constitutive expression of PCH1 shortens hypocotyls independent of day length. PCH1 peaks at dusk, binds phytochrome B (phyB) in a red light-dependent manner, and co-localizes with phyB into photobodies. PCH1 is necessary and sufficient to promote the biogenesis of large photobodies to maintain an active phyB pool after light exposure, potentiating red-light signaling and prolonging memory of prior illumination. Manipulating PCH1 alters PHYTOCHROME INTERACTING FACTOR 4 levels and regulates lightresponsive gene expression. Thus, PCH1 is a new factor that regulates photoperiod-responsive growth by integrating the clock with light perception pathways through modulating daily phyBsignaling.