The PRT6 N-degron pathway restricts VERNALIZATION 2 to endogenous hypoxic niches to modulate plant development

Research output: Contribution to journalArticlepeer-review


  • Hannah M. Tedds
  • Colleen Sprigg
  • Ross D. Etherington
  • Olunwatunmise Akintewe
  • Geetika Kalleechurn
  • Michael J. Holdsworth

External organisations

  • School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, UK.


VERNALIZATION2 (VRN2), an angiosperm-specific subunit of the polycomb repressive complex 2 (PRC2), is an oxygen (O2)-regulated target of the PCO branch of the PRT6 N-degron pathway of ubiquitin-mediated proteolysis. How this post-translational regulation coordinates VRN2 activity remains to be fully established. Here we use Arabidopsis thaliana ecotypes, mutants and transgenic lines to determine how control of VRN2 stability contributes to its functions during plant development. VRN2 localizes to endogenous hypoxic regions in aerial and root tissues. In the shoot apex, VRN2 differentially modulates flowering time dependent on photoperiod, whilst its presence in lateral root primordia and the root apical meristem negatively regulates root system architecture. Ectopic accumulation of VRN2 does not enhance its effects on flowering, but does potentiate its repressive effects on root growth. In late-flowering vernalization-dependent ecotypes, VRN2 is only active outside meristems when its proteolysis is inhibited in response to cold exposure, as its function requires concomitant cold-triggered increases in other PRC2 subunits and cofactors. We conclude that the O2-sensitive N-degron of VRN2 has a dual function, confining VRN2 to meristems and primordia, where it has specific developmental roles, whilst also permitting broad accumulation outside of meristems in response to environmental cues, leading to other functions.

Bibliographic note

Funding Information: This work was supported by a European Research Council Starter Grant (ERC-STG 715441-GasPlaNt) to DJG, grants from the Biotechnology and Biological Sciences Research Council to DJG (BB/M020568/1) and MJH (BB/M007820/1 and BB/M029441/1), and an EMBO Long Term Fellowship (ALTF 219-2018) to A-ML. Publisher Copyright: © 2020 The Authors. New Phytologist © 2020 New Phytologist Trust


Original languageEnglish
Pages (from-to)126-139
Number of pages14
JournalNew Phytologist
Issue number1
Early online date10 Feb 2020
Publication statusPublished - Jan 2021


  • N-degron pathway, PRC2, flowering time, hypoxia, polycomb, proteolysis, root, vernalization

ASJC Scopus subject areas