Two linked pairs of Arabidopsis TNL resistance genes independently confer recognition of bacterial effector AvrRps4

Nat Commun. 2015 Mar 6;6:6338. doi: 10.1038/ncomms7338.

Abstract

Plant immunity requires recognition of pathogen effectors by intracellular NB-LRR immune receptors encoded by Resistance (R) genes. Most R proteins recognize a specific effector, but some function in pairs that recognize multiple effectors. Arabidopsis thaliana TIR-NB-LRR proteins RRS1-R and RPS4 together recognize two bacterial effectors, AvrRps4 from Pseudomonas syringae and PopP2 from Ralstonia solanacearum. However, AvrRps4, but not PopP2, is recognized in rrs1/rps4 mutants. We reveal an R gene pair that resembles and is linked to RRS1/RPS4, designated as RRS1B/RPS4B, which confers recognition of AvrRps4 but not PopP2. Like RRS1/RPS4, RRS1B/RPS4B proteins associate and activate defence genes upon AvrRps4 recognition. Inappropriate combinations (RRS1/RPS4B or RRS1B/RPS4) are non-functional and this specificity is not TIR domain dependent. Distinct putative orthologues of both pairs are maintained in the genomes of Arabidopsis thaliana relatives and are likely derived from a common ancestor pair. Our results provide novel insights into paired R gene function and evolution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics*
  • Arabidopsis / immunology
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Bacterial Proteins / metabolism*
  • Chromosome Mapping
  • DNA Primers / genetics
  • Evolution, Molecular
  • Immunoblotting
  • Phylogeny
  • Plant Immunity / genetics*
  • Plant Leaves / genetics
  • Plant Leaves / metabolism
  • Plant Proteins / metabolism*
  • Proteins / genetics
  • Proteins / metabolism
  • Pseudomonas syringae / genetics
  • Pseudomonas syringae / metabolism
  • Ralstonia solanacearum / genetics
  • Ralstonia solanacearum / metabolism
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • Species Specificity
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*

Substances

  • Arabidopsis Proteins
  • Bacterial Proteins
  • DNA Primers
  • Plant Proteins
  • Proteins
  • RPS4B protein, Arabidopsis
  • RRS1 protein, Arabidopsis
  • TTR1 protein, Arabidopsis
  • Transcription Factors
  • leucine-rich repeat proteins
  • rps4 protein, plant