Small Ubiquitin-like Modifier protein SUMO enables plants to control growth independently of the phytohormone gibberellin

Dev Cell. 2014 Jan 13;28(1):102-10. doi: 10.1016/j.devcel.2013.12.004.

Abstract

Plants survive adverse conditions by modulating their growth in response to a changing environment. Gibberellins (GAs) play a key role in these adaptive responses by stimulating the degradation of growth-repressing DELLA proteins. GA binding to its receptor GID1 enables association of GID1 with DELLAs. This leads to the ubiquitin-mediated proteasomal degradation of DELLAs and consequently growth promotion. We report that DELLA-dependent growth control can be regulated independently of GA. We demonstrate that when a proportion of DELLAs is conjugated to the Small Ubiquitin-like Modifier (SUMO) protein, the extent of conjugation increases during stress. We identify a SUMO-interacting motif in GID1 and demonstrate that SUMO-conjugated DELLA binds to this motif in a GA-independent manner. The consequent sequestration of GID1 by SUMO-conjugated DELLAs leads to an accumulation of non-SUMOylated DELLAs, resulting in beneficial growth restraint during stress. We conclude that plants have developed a GA-independent mechanism to control growth.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / genetics
  • Arabidopsis / growth & development
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Binding Sites
  • Gibberellins / metabolism*
  • Molecular Sequence Data
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism
  • Repressor Proteins / chemistry
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • SUMO-1 Protein / genetics
  • SUMO-1 Protein / metabolism*
  • Stress, Physiological

Substances

  • Arabidopsis Proteins
  • GID1a protein, Arabidopsis
  • Gibberellins
  • RGA protein, Arabidopsis
  • Receptors, Cell Surface
  • Repressor Proteins
  • SUMO-1 Protein