Identification of a putative voltage-gated Ca2+ channel as a key regulator of elicitor-induced hypersensitive cell death and mitogen-activated protein kinase activation in rice

Plant J. 2005 Jun;42(6):798-809. doi: 10.1111/j.1365-313X.2005.02415.x.

Abstract

Elicitor-triggered transient membrane potential changes and Ca2+ influx through the plasma membrane are thought to be important during defense signaling in plants. However, the molecular bases for the Ca2+ influx and its regulation remain largely unknown. Here we tested effects of overexpression as well as retrotransposon (Tos17)-insertional mutagenesis of the rice two-pore channel 1 (OsTPC1), a putative voltage-gated Ca(2+)-permeable channel, on a proteinaceous fungal elicitor-induced defense responses in rice cells. The overexpressor showed enhanced sensitivity to the elicitor to induce oxidative burst, activation of a mitogen-activated protein kinase (MAPK), OsMPK2, as well as hypersensitive cell death. On the contrary, a series of defense responses including the cell death and activation of the MAPK were severely suppressed in the insertional mutant, which was complemented by overexpression of the wild-type gene. These results suggest that the putative Ca(2+)-permeable channel determines sensitivity to the elicitor and plays a role as a key regulator of elicitor-induced defense responses, activation of MAPK cascade and hypersensitive cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Calcium / metabolism
  • Calcium Channels / physiology*
  • Cell Death / physiology*
  • Endo-1,4-beta Xylanases
  • Enzyme Activation
  • Fungal Proteins
  • Gene Expression
  • Mitogen-Activated Protein Kinases / metabolism*
  • Mutagenesis, Insertional
  • Oryza / physiology*
  • Plant Proteins / genetics
  • Plant Proteins / metabolism
  • Reactive Oxygen Species
  • Signal Transduction
  • Trichoderma / enzymology

Substances

  • Calcium Channels
  • Fungal Proteins
  • Plant Proteins
  • Reactive Oxygen Species
  • Mitogen-Activated Protein Kinases
  • Endo-1,4-beta Xylanases
  • Calcium