Fusarium virguliforme Transcriptional Plasticity Is Revealed by Host Colonization of Corn vs. Soybean.

We exploited the broad host range of Fusarium virguliforme to identify differential fungal responses leading to either an endophytic or a pathogenic lifestyle during colonization of corn (Zea mays) and soybean (Glycine max), respectively. To provide a foundation to survey the transcriptomic landscape, we produced an improved de novo genome assembly and annotation of F. virguliforme using PacBio sequencing. Next, we conducted a high-resolution time course of F. virguliforme colonization and infection of both soybean, a symptomatic host, and corn, an asymptomatic host. Comparative transcriptomic analyses uncovered a nearly complete network rewiring, with less than 8% average gene coexpression module overlap upon colonizing the different plant hosts. Divergence of transcriptomes originating from host specific temporal induction genes is central to infection and colonization, including carbohydrate-active enzymes (CAZymes) and necrosis inducing effectors. Upregulation of Zn(II)-Cys6 transcription factors were uniquely induced in soybean at 2 days post-inoculation, suggestive of enhanced pathogen virulence on soybean. In total, the data described herein suggest that F. virguliforme modulates divergent infection profiles through transcriptional plasticity.