Mitogen-activated protein kinase (MAPK) plays a central role in controlling a vast array of plant biochemical and physiological processes. it is regulated by a characteristic phosphorelay system in which a series of three kinases phosphorylate and activate each other. Over the past years, several plants MAPKs have been identified and characterized. Of these, rice OsSIPK (Salicylic acid (SA)-Induced Protein Kinase) and its orthologs in other plants are of particular interest. A large body of evidence demonstrates the involvement of SIPKs in fine-tuned regulation Of the plant responses to ozone, wounding, SA, and jasmonic acid (JA). Interestingly, their function appears to be conserved across reference plants, Such as rice, tobacco, and Arabidopsis. In this minireview, we discuss the recent progress on rice OsSIPK and its orthologs as a "central master switch" for mediating plant responses against ozone, wounding, and JA as examples. (C) 2008 Elsevier Inc. All rights reserved.