The MAPK(mitogen-activated protein kinase)signaling pathway cascades are relativity conserved in eukaryotes,including yeasts,animals and plants.The classical MAPK signaling pathway cascade minimally contains three-component kinases,an activated MAPK kinase kinase(MAPKKK),activated MAPK kinase(MAPKK)and the MAPK(MAPK).These kinases operate as sequential signal transducers that channel,integrate and amplify information from the cellular environment to transcriptional and metabolic response centers via phosphorylation.Recently,many inhibitors of MAPKs(JNKs,P38 and ERKs)in Mammals have been developed as drug successfully and some of them are on the market,such as tofacitinib,sorafenib and so on.Pmk1,MoOsm1 and Mps1,the homologs of JNKs,P38 and ERKs in the rice blast fungus Magnaporthe oryzae,are essential for the infection and regulate pathogenesis to rice.These MAPKs,which are evolutionarily conserved in plant pathogenic fungi,can be considered as key targets of fungicide design for the phytopathogenic fungi.To further understand the structure bases of how these kinases interact with their inhibitors and design novel fungicides based on the structures of these kinases,the recombinant MAPKs(Pmk1,MoOsm1 and Mps1)in M.oryzae were expressed in Escherichia coli and purified to homogeneity.