Functional Analysis Of Protein Kinase Mokin1 In Manaporthe Oryzae

Magnaporthe oryzae,the causal agent of rice blast disease,is an important model fungal pathogen for understanding the molecular basis of plant-fungus interaction.Rise blast disease is one of the most severe fungal disease of rice throughout the world.The small GTPase Rho3 is conserved in fungi and plays a key role in the control of appressorium development and pathogenicity in M.oryzae.MoKin1 is a homolog to Kin1 and Kin2 in Saccharomyces cerevisiae that are potent suppressors of secretion defective alleles of Rho3 and Cdc42 and act downstream of the Rab-GTPase Sec4 and several components of the vesicle tethering complex,the exocyst.In S.cerevisiae,Kin1 and Kin2 physically associate with the t-SNARE Sec9 and the SNARE-binding protein Sro7.In this study,we identified and functional characterized the MoKin1 gene and found the genetically interaction between MoRho3 and MoKin1 in M.oryzae.The MoKin1 deletion mutants displayed reduced mycelial growth and conidia formation,but had little affect on conidial germination and appressorium development.However,MoKin1 is required for infection and plant-invasive growth because the appressoria formed by the MoKin1 deletion mutants are defective without well-established turgor pressure in plant penetration.Our results indicate that MoRho3 and MoKin1 have similar function in regulation of conidiogenesis and appressorial penetration being worthwhile to conduct a further study.