Genome evolution and functional adaptation of the species complex Fusarium oxysporum

Fusarium oxysporum is a highly adaptive species complex causing destructive and intractable wilt diseases across a broad spectrum of plant hosts. The Fusarium comparative genomics demonstrates that horizontal transfer of entire chromosomes conveys pathogenicity and contributes directly to the niche adaptation. This discovery establishes F. oxysporum as an effective model to investigate horizontal transfer in eukaryotes, and the pathogenicity chromosomes provide a focal point to investigate the genetic mechanisms that underlie pathogenesis against different plant hosts. Using two F. oxysporum strains, Fo5176 and Fo47, which give distinctive phenotypes when inoculating the root of Arabidopsis ecotype Col-0, we have established the F. oxysporum-Arabidopsis systems capturing either the pathogenic or the non-pathogenic interaction. A comprehensive RNAseq experiment at 12, 24, 48 and 96 hours post inoculation revealed distinct signaling pathways involved in the pathogenic versus non-pathogenic interactions. These results highlight the dynamic nature of fungal-plant interactions.