Functional Analysis Of MoGYP1 In Magnaporthe Oryzae

Magnaporthe oryzae,the fungal pathogen causing rice blast disease,is a model organism for studying the interaction mechanism between plant host and filamentous pathogenic fungus.Gyp1,a Golgi-associated protein,is characterized as the first GTPase-activating protein(GAP)in the Rab GAP cascade,which critically regulates membrane trafficking from the endoplasmic reticulum to the plasma membrane.In this study,we preliminarily characterized the function of Gyp1 homolog in M.oryzae.Three MoGYP1 gene deletion mutants,?Mogyp1-30,?Mogyp1-31 and?Mogyp1-38,were generated through homologous recombination strategy.Phenotypic analysis results showed that disruption of MoGYP1 led to defects in vegetative growth and conidiation,and mutants completely lost pathogenicity on rice and barley.The subcellular localization of MoGyp1-GFP confirmed by confocal microscopy,was colocalized with the cellular structures stained by the amphiphilic styryl dye FM4-64,which indicated that MoGyp1 was localized in endomembrane system.In addition,the most striking phenotype of these mutants were their phenotypic heterogeneity.10 strains were isolated from the colonial sectors of the original ?Mogyp1 mutants,and the growth,conidiation and pathogenicity of some isolates were partially restored.Taken together,these findings suggested that deletion of MoGYP1 could generate spontaneous mutation which activate unknown compensatory changes to improve the fitness of deletion mutants.