Identification of genes of Colletotrichum graminicola involved in establishment and maintenance of compatibiliy

Colletotrichum graminicola is the causal agent of the economically important maize anthracnose disease. In a compatible interaction, this hemibiotrophic fungus establishes a biotrophic, followed by a necrotrophic interaction. Our main interest is focused on the identification of fungal genes that mediate compatibility with its host. We turned out Agrobacterium tumefaciens-mediated transformation (ATMT) as a suitable method to generate virulence/pathogenicity mutants of C. graminicola. This way, genes were tagged by non-targeted integration of the T-DNA. We showed that single integrations of the T-DNA occurred more often than double or multiple integrations, emphasizing ATMT as a powerful tool to tag genes and to trace back the mutant s phenotype to the loss of only one gene function. As different mutants are hampered in different steps of the infection process, it seems that different genomic regions linked to virulence can get disrupted by ATMT. Sequence information of the region adjacent to the tagged loci can provide knowledge about genes, which contribute to the fungal virulence. To characterize these candidate genes functionally, we will delete candidate genes in the genome of C. graminicola and investigate the virulence behavior of the deletion mutants.