Arabidopsis ubiquitin ligase MIEL1 mediates degradation of the transcription factor MYB30 weakening plant defence

Nat Commun. 2013;4:1476. doi: 10.1038/ncomms2479.

Abstract

One of the most efficient plant resistance reactions to pathogen attack is the hypersensitive response, a form of programmed cell death at infection sites. The Arabidopsis transcription factor MYB30 is a positive regulator of hypersensitive cell death responses. Here we show that MIEL1 (MYB30-Interacting E3 Ligase1), an Arabidopsis RING-type E3 ubiquitin ligase that interacts with and ubiquitinates MYB30, leads to MYB30 proteasomal degradation and downregulation of its transcriptional activity. In non-infected plants, MIEL1 attenuates cell death and defence through degradation of MYB30. Following bacterial inoculation, repression of MIEL1 expression removes this negative regulation allowing sufficient MYB30 accumulation in the inoculated zone to trigger the hypersensitive response and restrict pathogen growth. Our work underlines the important role played by ubiquitination to control the hypersensitive response and highlights the sophisticated fine-tuning of plant responses to pathogen attack. Overall, this work emphasizes the importance of protein modification by ubiquitination during the regulation of transcriptional responses to stress in eukaryotic cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology*
  • Arabidopsis / genetics
  • Arabidopsis / immunology*
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Cell Nucleus / metabolism
  • Fluorescence Resonance Energy Transfer
  • Gene Expression Regulation, Plant
  • Microscopy, Confocal
  • Plant Cells / metabolism
  • Plant Diseases / immunology
  • Plant Diseases / microbiology
  • Plant Epidermis / cytology
  • Plant Epidermis / metabolism
  • Plants, Genetically Modified
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Binding
  • Protein Transport
  • Proteolysis*
  • Pseudomonas syringae / physiology
  • Tobacco / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Ubiquitin-Protein Ligases / metabolism*
  • Ubiquitination

Substances

  • Arabidopsis Proteins
  • MYB30 protein, Arabidopsis
  • Transcription Factors
  • MIEL1 protein, Arabidopsis
  • Ubiquitin-Protein Ligases
  • Proteasome Endopeptidase Complex