Abstract

Significance We identified an evolutionary lineage of RNA viruses within the proposed family Shuviridae, revealing an unexpected connection to animal viruses. Using a transfection system, we demonstrated that SsAShV1 confers hypovirulence, attenuating fungal pathogenicity. Furthermore, we found that the infection by a community of mycoviruses acts synergistically within the fungal genetic background to activate an ecological strategy: the enhanced production of broad-spectrum antifungal volatiles. This compensation mechanism ensures the persistence of the mycoviral-fungal partnership and offers a paradigm for controlling plant diseases by engineering microbes that can suppress pathogens through multiple, sustainable mechanisms.