The RPM1 plant disease resistance gene facilitates a rapid and sustained increase in cytosolic calcium that is necessary for the oxidative burst and hypersensitive cell death

Plant J. 2000 Aug;23(4):441-50. doi: 10.1046/j.1365-313x.2000.00804.x.

Abstract

Early events occurring during the hypersensitive resistance response (HR) were examined using the avrRpm1/RPM1 gene-for-gene interaction in Arabidopsis challenged by Pseudomonas syringae pv. tomato. Increases in cytosolic Ca2+ were measured in whole leaves using aequorin-mediated bioluminescence. During the HR a sustained increase in Ca2+ was observed which was dependent on the presence of both a functional RPM1 gene product and delivery of the cognate avirulence gene product AvrRpm1. The sequence-unrelated avirulence gene avrB, which also interacts with RPM1, generated a significantly later but similarly prolonged increase in cytosolic Ca2+. Accumulation of H2O2 at reaction sites, as revealed by electron microscopy, occurred within the same time frame as the changes in cytosolic Ca2+. The NADPH oxidase inhibitor diphenylene iodonium chloride did not affect the calcium signature, but did block H2O2 accumulation and the HR. By contrast, the calcium-channel blocker LaCl3 suppressed the increase in cytosolic Ca2+ as well as H2O2 accumulation and the HR, placing calcium elevation upstream of the oxidative burst.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aequorin
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism
  • Arabidopsis Proteins*
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Calcium Signaling*
  • Cell Death
  • Cytosol / metabolism
  • Enzyme Inhibitors / pharmacology
  • Hydrogen Peroxide / metabolism
  • Lanthanum / pharmacology
  • Luminescent Measurements
  • Microscopy, Electron
  • NADPH Oxidases / antagonists & inhibitors
  • Onium Compounds / pharmacology
  • Oxygen Consumption*
  • Plant Diseases / genetics*
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Pseudomonas / pathogenicity*
  • Reactive Oxygen Species / metabolism

Substances

  • Arabidopsis Proteins
  • AvrB protein, Pseudomonas syringae
  • Bacterial Proteins
  • Enzyme Inhibitors
  • Onium Compounds
  • Plant Proteins
  • RPM1 protein, Arabidopsis
  • Reactive Oxygen Species
  • lanthanum chloride
  • Aequorin
  • diphenyleneiodonium
  • Lanthanum
  • Hydrogen Peroxide
  • NADPH Oxidases