Protein kinases in elicitor signal transduction in plant cells

Plants have the ability to respond to pathogen invasion by specific defense reactions. Components of mammalian signal transduction chains have been identified in plants, and several lines of evidence have implicated such components in elicitor signal transmission in defense responses. In particular, it has been assumed that elicitor signals are transduced via a protein kinase cascade, although the identity of the protein kinases and the function of the phosphorylated proteins remain to be determined. The purpose of this review is to discuss the roles of protein kinases in elicitor signal transduction pathways in plant cells based on recent progress in this field.