MEDIATOR18 and MEDIATOR20 confer susceptibility to Fusarium oxysporum in Arabidopsis thaliana

PLoS One. 2017 Apr 25;12(4):e0176022. doi: 10.1371/journal.pone.0176022. eCollection 2017.

Abstract

The conserved protein complex known as Mediator conveys transcriptional signals by acting as an intermediary between transcription factors and RNA polymerase II. As a result, Mediator subunits play multiple roles in regulating developmental as well as abiotic and biotic stress pathways. In this report we identify the head domain subunits MEDIATOR18 and MEDIATOR20 as important susceptibility factors for Fusarium oxysporum infection in Arabidopsis thaliana. Mutants of MED18 and MED20 display down-regulation of genes associated with jasmonate signaling and biosynthesis while up-regulation of salicylic acid associated pathogenesis related genes and reactive oxygen producing and scavenging genes. We propose that MED18 and MED20 form a sub-domain within Mediator that controls the balance of salicylic acid and jasmonate associated defense pathways.

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology*
  • Arabidopsis Proteins / genetics*
  • Arabidopsis Proteins / metabolism
  • Cyclopentanes / metabolism
  • Disease Susceptibility
  • Down-Regulation
  • Fusarium / physiology*
  • Gene Expression Regulation, Plant
  • Mediator Complex / genetics*
  • Mediator Complex / metabolism
  • Oxylipins / metabolism
  • Plant Diseases / genetics*
  • Plant Diseases / microbiology
  • Salicylic Acid / metabolism
  • Up-Regulation

Substances

  • Arabidopsis Proteins
  • Cyclopentanes
  • MED18 protein, Arabidopsis
  • MED20 protein, Arabidopsis
  • Mediator Complex
  • Oxylipins
  • jasmonic acid
  • Salicylic Acid

Grants and funding

This work was supported by the Australian Research Council [http://www.arc.gov.au] grant no. DP110104354 to PMS, JMM, and KK. CD and SB were supported by grants from the Swedish Cancer Society (15 0537); the Swedish Research Council (621-2010-4969); the Swedish Governmental Agency for Innovation Systems, the Knut and Alice Wallenberg Foundation (2015-0056) and the Kempe Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.