Gene-for-gene relationship in the host-pathogen system Malus × robusta 5-Erwinia amylovora

New Phytol. 2013 Mar;197(4):1262-1275. doi: 10.1111/nph.12094. Epub 2013 Jan 10.

Abstract

Fire blight is a destructive bacterial disease caused by Erwinia amylovora affecting plants in the family Rosaceae, including apple. Host resistance to fire blight is present mainly in accessions of Malus spp. and is thought to be quantitative in this pathosystem. In this study we analyzed the importance of the E. amylovora effector avrRpt2(EA) , a homolog of Pseudomonas syringae avrRpt2, for resistance of Malus × robusta 5 (Mr5). The deletion mutant E. amylovora Ea1189ΔavrRpt2(EA) was able to overcome the fire blight resistance of Mr5. One single nucleotide polymorphism (SNP), resulting in an exchange of cysteine to serine in the encoded protein, was detected in avrRpt2(EA) of several Erwinia strains differing in virulence to Mr5. E. amylovora strains encoding serine (S-allele) were able to overcome resistance of Mr5, whereas strains encoding cysteine (C-allele) were not. Allele specificity was also observed in a coexpression assay with Arabidopsis thaliana RIN4 in Nicotiana benthamiana. A homolog of RIN4 has been detected and isolated in Mr5. These results suggest a system similar to the interaction of RPS2 from A. thaliana and AvrRpt2 from P. syringae with RIN4 as guard. Our data are suggestive of a gene-for-gene relationship for the host-pathogen system Mr5 and E. amylovora.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / genetics
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology*
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Disease Resistance / genetics
  • Erwinia amylovora / physiology*
  • Genes, Bacterial / physiology*
  • Genes, Plant / physiology*
  • Host-Pathogen Interactions / genetics*
  • Intracellular Signaling Peptides and Proteins
  • Malus / microbiology*
  • Nicotiana / genetics
  • Plant Diseases / microbiology
  • Plant Proteins / chemistry
  • Plant Proteins / genetics
  • Plant Proteins / physiology*
  • Point Mutation
  • Polymorphism, Single Nucleotide
  • Sequence Alignment

Substances

  • Arabidopsis Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • Intracellular Signaling Peptides and Proteins
  • Plant Proteins
  • RIN4 protein, Arabidopsis