Tobacco transcription factor WRKY1 is phosphorylated by the MAP kinase SIPK and mediates HR-like cell death in tobacco

Mol Plant Microbe Interact. 2005 Oct;18(10):1027-34. doi: 10.1094/MPMI-18-1027.


The salicylic acid-induced protein kinase (SIPK) of tobacco, which is a mitogen-activated protein kinase (MAPK), is activated by various biotic and abiotic treatments. Overexpression of SIPK has been shown to trigger cell death. In this study, a targeted yeast two-hybrid approach identified the tobacco transcription factor WRKY1 as a potential substrate. SIPK phosphorylated WRKY1, which resulted in enhanced DNA-binding activity of WRKY1 to its cognate binding site, a W box sequence from the tobacco chitinase gene CHN50. SIPK-mediated enhancement of WRKY1 DNA-binding activity was inhibited by staurosporine, a general kinase inhibitor. Co-expression of SIPK and WRKY1 in Nicotiana benthamiana led to more rapid cell death than expression of SIPK alone, suggesting that WRKY1 is involved in the formation of hypersensitive response-like cell death and may be a component of the signaling cascade downstream of SIPK.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Arabidopsis Proteins / metabolism*
  • Arabidopsis Proteins / physiology
  • Cell Death / physiology*
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / physiology
  • Electrophoretic Mobility Shift Assay
  • Mitogen-Activated Protein Kinases / metabolism*
  • Phosphorylation
  • Plant Proteins
  • Plants, Genetically Modified
  • Protein Binding
  • Tobacco / cytology*
  • Tobacco / metabolism*
  • Transcription Factors / metabolism*
  • Transcription Factors / physiology


  • Arabidopsis Proteins
  • DNA-Binding Proteins
  • Plant Proteins
  • Transcription Factors
  • ZAP1 protein, Arabidopsis
  • Mitogen-Activated Protein Kinases
  • SA-induced protein kinase