A Mycovirus VIGS Vector Confers Hypovirulence to a Plant Pathogenic Fungus to Control Wheat FHB

Mycovirus‐mediated hypovirulence has the potential to control fungal diseases. However, the availability of hypovirulence‐conferring mycoviruses for plant fungal disease control is limited as most fungal viruses are asymptomatic. In this study, the virus‐induced gene silencing (VIGS) vector p26‐D4 of Fusarium graminearum gemytripvirus 1 (FgGMTV1), a tripartite circular single‐stranded DNA mycovirus, is successfully constructed to convert the causal fungus of cereal Fusarium head blight (FHB) into a hypovirulent strain. p26‐D4, with an insert of a 75–150 bp fragment of the target reporter transgene transcript in both sense and antisense orientations, efficiently triggered gene silencing in Fusarium graminearum. Notably, the two hypovirulent strains, p26‐D4‐Tri101, and p26‐D4‐FgPP1, obtained by silencing the virulence‐related genes Tri101 and FgPP1 with p26‐D4, can be used as biocontrol agents to protect wheat from a fungal disease FHB and mycotoxin contamination at the field level. This study not only describes the first mycovirus‐derived VIGS system but also proves that the VIGS vector can be used to establish multiple hypovirulent strains to control pathogenic fungi.