Targeted Disruption Of A G Protein Alpha Subunit Gene Results In Reduced Growth And Pathogenicity In Rhizoctonia Solani

Cloning and disruption of Rga1, the gene encoding the G protein alpha subunit in the rice sheath blight fungus Rhizoctonia solani, was investigated. The deduced primary structure of the Rga1-encoded protein showed high identity to those of G alpha subunits from other filamentous fungi. Disruption of Rga1 led to decreased vegetative growth and pathogenicity. The Rga1 disruptant showed altered colony morphology. In addition, the sclerotia formation ability of the disruptant was completely lost. These results suggest that the G alpha subunit encoded by Rga1 is involved in a signal transduction pathway in R. solani that controls growth, development and pathogenicity.