COP1 destabilizes DELLA proteins inArabidopsis

  1. Noel Blanco-Touriñán
  2. Martina Legris
  3. Eugenio G. Minguet
  4. Cecilia Costigliolo-Rojas
  5. MarĂ­a A. Nohales
  6. Elisa Iniesto
  7. Marta GarcĂ­a-LeĂłn
  8. Manuel PacĂ­n
  9. Nicole Heucken
  10. Tim Blomeier
  11. Antonella Locascio
  12. Martin ÄŚernĂ˝
  13. David Esteve-Bruna
  14. MĂłnica DĂ­ez-DĂ­az
  15. Břetislav Brzobohatý
  16. Henning Frerigmann
  17. MatĂ­as D. Zurbriggen
  18. Steve A. Kay
  19. Vicente Rubio
  20. Miguel A. Blázquez
  21. Jorge J. Casal
  22. David AlabadĂ­
1 evaluations Published on
Read the full article Related papers
This article on Sciety

Abstract

DELLA transcriptional regulators are central components in the control of plant body form in response to the environment. This is considered to be mediated by changes in the metabolism of the hormones gibberellins (GAs), which promote the degradation of DELLAs. However, here we show that warm temperature or shade reduced the stability of a GA-insensitive DELLA allele inArabidopsis. Furthermore, the degradation of DELLA induced by the warmth anticipated changes in GA levels and depended on the E3 ubiquitin ligase CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1). COP1 enhanced the degradation of normal and GA-insensitive DELLA alleles when co-expressed inN. benthamiana.DELLA proteins physically interacted with COP1 in yeast, mammalian and plant cells. This interaction was enhanced by the COP1 complex partner SUPRESSOR OFphyA-1051 (SPA1). The level of ubiquitination of DELLA was enhanced by COP1 and COP1 ubiquitinated DELLA proteins in vitro. We propose that DELLAs are destabilized not only by the canonical GA-dependent pathway but also by COP1 and that this control is relevant for growth responses to shade and warm temperature.

Significance

DELLA proteins are plant-specific transcriptional regulators that act as signaling hubs at the interface between the environment and the transcriptional networks that control growth. DELLAs are destabilized by the growth-promoting hormone gibberellin, whose levels are very sensitive to environmental changes. Here we describe an alternative pathway to destabilize these proteins. We show that DELLAs are substrate of COP1, an E3 ubiquitin ligase that increases its nuclear activity to promote growth in response to shade or warmth. Our results also show that the destabilization of DELLAs by COP1 precedes the action of gibberellins, suggesting the existence of a sequential mechanism to control the stability of these proteins.

Related articles

Related articles are currently not available for this article.