Are Fungal Disease Outbreaks Instigated by Starship Transposons?

Abstract

New outbreaks of fungal diseases are an ongoing threat to global agriculture. One known mechanism generating novel diseases is the horizontal transfer of genes between fungal species. Yet we have little understanding of how such transfers are mediated. Here, we raise the possibility that Starships, a recently discovered superfamily of giant transposable elements, might be responsible. To support this hypothesis, we discuss three potential cases where Starships may have mediated disease outbreaks. These are ToxA in wheat pathogens, genes underlying Glomerella leaf spot on apple trees, and the defoliating gene cluster of Verticillium dahliae on cotton. In the Verticillium example, we provide strong evidence for a Starship-mediated mechanism: disease-promoting genes reside in closely related Starships across distantly related species. We aim to spark interest in Starships' roles in fungal pathogens and how this knowledge could inform disease management strategies.