The Arabidopsis RRM domain protein EDM3 mediates race-specific disease resistance by controlling H3K9me2-dependent alternative polyadenylation of RPP7 immune receptor transcripts

Plant J. 2019 Feb;97(4):646-660. doi: 10.1111/tpj.14148. Epub 2018 Dec 18.

Abstract

The NLR-receptor RPP7 mediates race-specific immunity in Arabidopsis. Previous screens for enhanced downy mildew (edm) mutants identified the co-chaperone SGT1b (EDM1) and the PHD-finger protein EDM2 as critical regulators of RPP7. Here, we describe a third edm mutant compromised in RPP7 immunity, edm3. EDM3 encodes a nuclear-localized protein featuring an RNA-recognition motif. Like EDM2, EDM3 promotes histone H3 lysine 9 dimethylation (H3K9me2) at RPP7. Global profiling of H3K9me2 showed EDM3 to affect this silencing mark at a large set of loci. Importantly, both EDM3 and EDM2 co-associate in vivo with H3K9me2-marked chromatin and transcripts at a critical proximal polyadenylation site of RPP7, where they suppress proximal transcript polyadeylation/termination. Our results highlight the complexity of plant NLR gene regulation, and establish a functional and physical link between a histone mark and NLR-transcript processing.

Keywords: Hyaloperonospora arabidopsidis; RNA-binding protein; disease-resistance genes; histone-binding proteins; transcript processing.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Gene Expression Regulation, Plant / genetics
  • Gene Expression Regulation, Plant / physiology
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism

Substances

  • Arabidopsis Proteins
  • RNA-Binding Proteins
  • RPP7 protein, Arabidopsis

Associated data

  • GENBANK/GSE108490
  • GENBANK/SRR5515902
  • GENBANK/SRR5515903
  • GENBANK/SRR5515906
  • GENBANK/SRR5515907