Interplay between calcium signalling and early signalling elements during defence responses to microbe- or damage-associated molecular patterns

Plant J. 2011 Oct;68(1):100-13. doi: 10.1111/j.1365-313X.2011.04671.x. Epub 2011 Jul 14.

Abstract

While diverse microbe- or damage-associated molecular patterns (MAMPs/DAMPs) typically trigger a common set of intracellular signalling events, comparative analysis between the MAMPs flg22 and elf18 revealed MAMP-specific differences in Ca(2+) signalling, defence gene expression and MAMP-mediated growth arrest in Arabidopsis thaliana. Such MAMP-specific differences are, in part, controlled by BAK1, a kinase associated with several receptors. Whereas defence gene expression and growth inhibition mediated by flg22 were reduced in bak1 mutants, BAK1 had no or minor effects on the same responses elicited by elf18. As the residual Ca(2+) elevations induced by diverse MAMPs/DAMPs (flg22, elf18 and Pep1) were virtually identical in bak1 mutants, a differential BAK1-mediated signal amplification to attain MAMP/DAMP-specific Ca(2+) amplitudes in wild-type plants may be hypothesized. Furthermore, abrogation of reactive oxygen species (ROS) accumulation, either in the rbohD mutant or through inhibitor application, led to loss of a second Ca(2+) peak, demonstrating a feedback effect of ROS on Ca(2+) signalling. Conversely, mpk3 mutants showed a prolonged accumulation of ROS but this did not significantly impinge on the overall Ca(2+) response. Thus, fine-tuning of MAMP/DAMP responses involves interplay between diverse signalling elements functioning both up- or downstream of Ca(2+) signalling.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabidopsis / enzymology
  • Arabidopsis / genetics
  • Arabidopsis / microbiology
  • Arabidopsis / physiology*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Calcium / metabolism
  • Calcium Signaling / physiology*
  • Gene Expression Regulation, Plant / physiology*
  • Genes, Plant / genetics
  • Hydrogen Peroxide / metabolism
  • Mitogen-Activated Protein Kinases / genetics
  • Mitogen-Activated Protein Kinases / metabolism
  • Mutation
  • Plant Diseases / immunology*
  • Plant Diseases / microbiology
  • Plant Immunity / physiology*
  • Plant Leaves / genetics
  • Plant Leaves / immunology
  • Plant Leaves / microbiology
  • Plant Leaves / physiology
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Plant Roots / genetics
  • Plant Roots / immunology
  • Plant Roots / microbiology
  • Plant Roots / physiology
  • Plant Shoots / genetics
  • Plant Shoots / immunology
  • Plant Shoots / microbiology
  • Plant Shoots / physiology
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Protoplasts
  • Reactive Oxygen Species / metabolism
  • Receptors, Pattern Recognition / genetics
  • Receptors, Pattern Recognition / metabolism
  • Seedlings / genetics
  • Seedlings / immunology
  • Seedlings / microbiology
  • Seedlings / physiology

Substances

  • Arabidopsis Proteins
  • Plant Proteins
  • Reactive Oxygen Species
  • Receptors, Pattern Recognition
  • Hydrogen Peroxide
  • Protein Kinases
  • BAK1 protein, Arabidopsis
  • SERK protein, plant
  • Protein-Serine-Threonine Kinases
  • Mitogen-Activated Protein Kinases
  • Calcium