Identification Of The MoDbf2 Interacting Proteins And Functional Characterization Of Its Interaction Component,MoMob1 In Magnaporthe Oryzae

Dbf2 is a serine/threonine protein kinase that plays an important role in the cytoskeleton,membrane tissue,intracellular signaling and vesicle transport of eukaryotic cells.The protein kinase Dbf2 belongs to the NDR(Nuclear Dbf2-Related)kinase family.Previous studies have shown that the NDR kinase sequence in eukaryotes is highly conserved and regulates cell mitosis,growth,and development.The cytokinesis process of fungi requires the activation of a very conserved signaling network,which is called the Mitotic Exit Network(MEN)in budding yeast.Dbf2 and Mob1 are part of the signaling pathway.In budding yeast,Dbf2 and Mob1 form a complex,and Mob1 is a co-activator of Dbf2.In this study,a number of proteins that may interact with Mo Dbf2 in Magnaporthe oryzae were predicted by bioinformatics analysis with reference to the Dbf2 signaling pathway regulating mitosis in Saccharomyces cerevisiae.Subsequently,we used the yeast two-hybrid method for verification,and we screened and verified that only Mo Mob1 could directly interact with Mo Dbf2.Therefore,we explored the function of Mo Mob1 in M.oryzae,and obtained the knockout mutant ΔMomob1by using the gene knockout principle of homologous recombination,and then inferred the function of the gene by observing the phenotypic change of the mutant.We found that when compared to the wild-type Ku80,the deletion of the Mo MOB1 significantly inhibited the growth rate of the colonies,severely deformed the morphology of the conidia,significantly reduced conidiation and membranes.The formation of appressorium is significantly delayed,and the infectious capacity of pathogenic is significantly reduced.The subcellular localization showed that Mo Mob1 was localized to the septum of the hypha,which was the same as the subcellular localization of Mo Dbf2 in the hypha.The above results indicate that Mo Mob1 is essential for the development and pathogenic infection of M.oryzae.In order to further explore the function of Mo Mob1,we transferred the Mo MOB1 overexpression vector into theΔModbf2 knockout mutant strain,and performed phenotypic analysis.It was observed that the original growth defect of the ΔModbf2 strain did not recover,and had no change in pathogenicity.In summary,Mo Mob1 can directly interact with Mo Dbf2,and regulate the cell growth,conidial germination,septum and appressorium formation in M.oryzae.Mo Mob1 and Mo Dbf2 play different functions in regulating the cytokinesis of M.oryzae,and their specific regulatory mechanisms need to be further studied.