Symptomless resistant response instead of the hypersensitive reaction in tobacco leaves after infiltration of heterologous pathovars of Pseudomonas syringae

Z. Klement, Z. Bozsó, P. G. Ott, M. L. Kecskés, K. Rudolph

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

Following the infiltration of heterologous pathovars of Pseudomonas syringae two localized responses develop in a parallel manner in tobacco leaves: an early form of induced resistance (EIR) and the hypersensitive reaction (HR). The EIR inhibits the metabolic activity of infiltrated bacteria and the leaf tissue remains symptomless whereas HR also inhibits bacteria, but the leaf tissue shows confluent necrosis or necrosis of individual plant cells, depending on the inoculum concentration. After infiltration of a heterologous strain the rapid development of HR usually masks the effects of EIR which is developing at the same time. The aim of this study was to characterize the conditions in which EIR occurs in the absence of HR following the infiltration of heterologous pathovars of Pseudomonas syringae pathovars. A study was made of numerous experimental interactions of heterologous bacteria/tobacco leaves in which the H R induction time of the bacteria and/or the EIR response of the plant were modified. When (a) the HR induction time was extended by chloramphenicol treatment of bacterial cells or by using transposon mutants (Tn5), or (b) the time needed for the development of EIR was shortened (at 30°C or in young leaves) the heterologous strains were unable to induce visible HR. But when the EIR was suppressed in tobacco leaves by pretreatment with cycloheximide or thermal shock (50°C for 13 s) the HR appeared. Comparison of results of numerous experiments revealed that solely EIR was present if its development time was shorter than the induction period of HR. This interpretation was confirmed by the infiltration of partially purified harpin(Pss) into tobacco leaves, where it caused plant cell death in the presence of EIR.

Original languageEnglish
Pages (from-to)467-475
Number of pages9
JournalJournal of Phytopathology
Volume147
Issue number7-8
DOIs
Publication statusPublished - Aug 1 1999

Keywords

  • Harpin
  • Hypersensitive response
  • Local induced resistance
  • Phytopathogenic bacteria
  • Transposon mutants

ASJC Scopus subject areas

  • Physiology
  • Agronomy and Crop Science
  • Genetics
  • Plant Science

Fingerprint Dive into the research topics of 'Symptomless resistant response instead of the hypersensitive reaction in tobacco leaves after infiltration of heterologous pathovars of Pseudomonas syringae'. Together they form a unique fingerprint.

  • Cite this