Functional Analysis Of Three Putative Genes Encoding Protein Tyrosine Phosphatases In Magnaporthe Oryzae

Tyrosine phosphorylation and dephosphorylation responsible by protein tyrosine kinases and protein tyrosine phosphatases play an important role in regulating various cellular processes,including cell-cell communication,cell proliferation and differentiation,embryonic development and intracellular trafficking.However,little is known about functions of protein tyrosine phosphatases in filamentous ftmgi.Magnaporthe oryzae contains seven putative genes encoding protein tyrosine phosphatases.In this study,we investigated biological functions of tihree putative protein tyrosine phosphatase(MoPtp1,MoPmp1 and MoPps1),the orthologs of Saccharomyces cerevisiae Ptp2,Msg5 and Pps1,respectively.To investigate the roles of MoPtp1,MoPmp1 and MoPps1,we generated the targeted gene deletion mutants of MoPTP1,MoPMP1 and MoPPS1 using a homologous recombination strategy.These deletion mutants showed the following phenotypic characters.(1)Comparing to the wild-type strain,the gene deletion mutants ?Moptp1,?Mopmp1 and ?Mopps1 produced much fewer condia and condiophores.(2)The deletion mutant ?Mopmp1 grew slower than the wild-type strain,but the deletion mutants ?Moptp1 and?Mopps1 showed no significant change in vegetative growth.(3)The deletion mutants ?Moptp1 and ?Mopmp1 were strongly reduced in virulence to barley and rice leaves.(4)The deletion mutant ?Moptp1 exhibited strongly increased sensitivity to osmotic stress mediated by NaC and KCl.By comparison,the deletion mutant?MoPMP1 exhibited slightly decreased sensitivity to osmotic stress mediated by NaCl and D-sorbital.Taken together,our results demonstrated that PTPs play an important role in growth,development,and pathogenesis.Our study has laid the foundation for further studying the functions of tyrosine phosphorylation and dephosphorylation in signal transduction pathway of Magnaporthe oryzae.