Evolution of pathogenicity in the vascular wilt pathogen Verticillium dahliae

Fungal pathogens cause severe crop losses and threaten food security worldwide. The soil-borne fungal pathogen Verticillium dahliae causes vascular wilt disease on hundreds of plant species, and disease control is challenging because the fungus is extremely persistant in the soil and resistance in plants is rare. Moreover, V. dahliae has a flexible genome allowing it to escape host immunity and maintain aggressiveness. Through comparative population genomics we unravel mechanisms to establish genomic diversity that is essential for adaptive genome co-evolution during the continued arms race with host plants. These analyses have revealed lineage-specific regions within V. dahliae genomes that are important for virulence. Interestingly, besides transposable elements these regions are enriched for in planta-expressed effector genes encoding secreted proteins that enable host colonization. Some of these effectors enable host specificity and even pathogenicity. With comparative genomics throughout the whole Verticillium genus and functional analyses, we try to understand why some Verticillium spp. are potent pathogens while other Verticillium spp. do not have the capacity to cause disease.