VRN2-PRC2 facilitates light-triggered repression of PIF signaling to coordinate growth in Arabidopsis

Rory Osborne; Anne-Marie Labandera; Alex J Ryder; Anastasia Kanali; Tianyuan Xu; Oluwatunmise Akintewe; Maximillian A Schwarze; Christian D Morgan; Sjon Hartman; Eirini Kaiserli; Daniel J Gibbs

doi:10.1016/j.devcel.2025.03.001

VRN2-PRC2 facilitates light-triggered repression of PIF signaling to coordinate growth in Arabidopsis

Dev Cell. 2025 Mar 20:S1534-5807(25)00122-4. doi: 10.1016/j.devcel.2025.03.001. Online ahead of print.

Affiliations

¹ School of Biosciences, University of Birmingham, Edgbaston B152TT, UK.
² School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
³ School of Biosciences, University of Birmingham, Edgbaston B152TT, UK. Electronic address: d.gibbs@bham.ac.uk.

PMID: 40147448
DOI: 10.1016/j.devcel.2025.03.001

Abstract

VERNALIZATION2 (VRN2) is a flowering plant-specific subunit of the polycomb-repressive complex 2 (PRC2), a conserved eukaryotic holoenzyme that represses gene expression by depositing the histone H3 lysine 27 trimethylation (H3K27me3) mark in chromatin. Previous work established VRN2 as an oxygen-regulated target of the N-degron pathway that may function as a sensor subunit connecting PRC2 activity to the perception of endogenous and environmental cues. Here, we show that VRN2 is enriched in the hypoxic shoot apex and emerging leaves of Arabidopsis, where it negatively regulates growth by establishing a stable and conditionally repressed chromatin state in key PHYTOCHROME INTERACTING FACTOR (PIF)-regulated genes that promote cell expansion. This function is required to keep these genes poised for repression via a light-responsive signaling cascade later in leaf development. Thus, we identify VRN2-PRC2 as a core component of a developmentally and spatially encoded epigenetic mechanism that coordinates plant growth through facilitating the signal-dependent suppression of PIF signaling.

Keywords: H3K27me3; N-degron pathway; PIF signaling; PRC2; cell expansion-mediated growth; chromatin modification; hypoxia; phytochrome; polycomb; red light signaling.