DNA demethylases are required for myo-inositol-mediated mutualism between plants and beneficial rhizobacteria

Nat Plants. 2020 Aug;6(8):983-995. doi: 10.1038/s41477-020-0707-2. Epub 2020 Jul 13.


Root-associated soil bacteria can strongly influence plant fitness. DNA methylation is an epigenetic mark important to many fundamental biological processes; however, its roles in plant interactions with beneficial microbes remain elusive. Here, we report that active DNA demethylation in Arabidopsis controls root secretion of myo-inositol and consequently plant growth promotion triggered by Bacillus megaterium strain YC4. Root-secreted myo-inositol is critical for YC4 colonization and preferentially attracts B. megaterium among the examined bacteria species. Active DNA demethylation antagonizes RNA-directed DNA methylation in controlling myo-inositol homeostasis. Importantly, we demonstrate that active DNA demethylation controls myo-inositol-mediated mutualism between YC4 and Solanum lycopersicum, thus suggesting a conserved nature of this epigenetic regulatory mechanism.

MeSH terms

  • Arabidopsis / metabolism
  • Arabidopsis / physiology
  • Bacillus megaterium / metabolism*
  • Bacillus megaterium / physiology
  • DNA Methylation* / physiology
  • Homeostasis
  • Inositol / metabolism*
  • Lycopersicon esculentum / metabolism
  • Lycopersicon esculentum / microbiology
  • Lycopersicon esculentum / physiology
  • Plant Roots / metabolism
  • Plant Roots / microbiology
  • Plant Roots / physiology
  • Symbiosis* / physiology


  • Inositol