The fire blight pathogen Erwinia amylovora requires the rpoN gene for pathogenicity in apple

Laura S. Ramos, Brian L. Lehman, Judith P. Sinn, Emily E. Pfeufer, Noemi O. Halbrendt, Timothy W. Mcnellis

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

RpoN is a σ54 factor regulating essential virulence gene expression in several plant pathogenic bacteria, including Pseudomonas syringae and Pectobacterium carotovorum. In this study, we found that mutation of rpoN in the fire blight pathogen Erwinia amylovora caused a nonpathogenic phenotype. The E.amylovora rpoN Tn5 transposon mutant rpoN1250::Tn5 did not cause fire blight disease symptoms on shoots of mature apple trees. In detached immature apple fruits, the rpoN1250::Tn5 mutant failed to cause fire blight disease symptoms and grew to population levels 12 orders of magnitude lower than the wild-type. In addition, the rpoN1250::Tn5 mutant failed to elicit a hypersensitive response when infiltrated into nonhost tobacco plant leaves, and rpoN1250::Tn5 cells failed to express HrpN protein when grown in hrp (hypersensitive response and pathogenicity)-inducing liquid medium. A plasmid-borne copy of the wild-type rpoN gene complemented all the rpoN1250::Tn5 mutant phenotypes tested. The rpoN1250::Tn5 mutant was prototrophic on minimal solid and liquid media, indicating that the rpoN1250::Tn5 nonpathogenic phenotype was not caused by a defect in basic metabolism or growth. This study provides clear genetic evidence that rpoN is an essential virulence gene of E.amylovora, suggesting that rpoN has the same function in E.amylovora as in P.syringae and Pe.carotovorum.

Original languageEnglish (US)
Pages (from-to)838-843
Number of pages6
JournalMolecular plant pathology
Volume14
Issue number8
DOIs
StatePublished - Oct 1 2013

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Agronomy and Crop Science
  • Soil Science
  • Plant Science

Fingerprint Dive into the research topics of 'The fire blight pathogen Erwinia amylovora requires the rpoN gene for pathogenicity in apple'. Together they form a unique fingerprint.

  • Cite this