Phytopathogenic fungus hosts a plant virus: A naturally occurring cross-kingdom viral infection

Abstract

Significance Virus cross-infection is an important topic in understanding the course of virus dissemination and evolution. Viruses may spread between the same host species or into taxonomically distinct organisms. The occurrences of cross-kingdom viral infection for certain virus groups are suggested by the current virus taxonomic data. In particular, several plants and fungal viruses show close phylogenetic relationships, but productive transmission of virus between plant and fungal hosts in nature has not been directly demonstrated. Here, we describe the natural infection of Rhizoctonia solani fungus by a plant virus, cucumber mosaic virus (CMV). We further demonstrate that R. solani can acquire and transmit CMV during plant infection. Our findings are evidence of cross-kingdom virus transmission from the plant to fungus.