Transcriptional plasticity of fast-core chromosomes governs establishment of a fungal pathogen on evolutionarily distant plant lineages

The Fusarium oxysporum (Fo) species complex harbors filamentous plant pathogens, some of whichprovokes systemic infections, leading to vascular-wilt disease. Different isolates of Fo exhibit contrasting lifestyles on diverse vascular hosts and current understanding of vascular-wilt disease by Fo, is primarily centered around flowering hosts. Although, Fo isolates displaying contrasting lifestyles on angiosperms have recently been shown to infect non-vascular liverwort Marchantia polymorpha (Mp), the molecular crosstalk and transcriptional co-ordination of Fo effectors during Mp infection, remains largely unknown. In this study, we took a comparative transcriptomic approach to understand how Fo isolates exhibiting contrasting interactions outcomes on angiosperms infect a distantly related non-vascular plant lineage. We identify core effector complement with genomic regions shared across different Fo isolates actively transcribed in Mp and lineage-specific (LS) genomic regions that contribute towards host-specific pathogenicity in angiosperms and have a dispensable role. Moreover, the highly syntenic Fo fast core-chromosomes show an enhanced transcriptional activation of effector-clusters during the Fo compatibility across divergent plant lineages and lifestyles suggesting their conserved role in plant associations. Fo mutant impared in an effector in one of the core effector-cluster leads to mis-regulation of other effectors. Collectively, our findings reveal an unexpected role of fast-core chromosomes of Fo in determining its compatibility across a broad-spectrum of plant lineages and charts the evolutionarily conserved gene-networks which are essential for plant-fungal associations.