Diverse partitiviruses hosted by the ectomycorrhizal agaric Hebeloma mesophaeum and the natural transmission of a partitivirus between phylogenetically distant, sympatric fungi

Virology. 2023 Apr:581:63-70. doi: 10.1016/j.virol.2023.03.002. Epub 2023 Mar 9.

Abstract

Mycorrhizal fungi host diverse mycoviruses that contribute to our understanding of their diversity and evolution. Here we report on the identification and complete genome characterization of three novel partitiviruses naturally infecting the ectomycorrhizal fungus Hebeloma mesophaeum. During NGS derived viral sequence analyses, we identified a partitivirus that is conspecific with the previously reported partitivirus (LcPV1) described from a saprotrophic fungus Leucocybe candicans. The two distinct fungal specimens inhabited the same vicinity of a campus garden. RdRp sequences encoded by the LcPV1 isolates from both host fungi was found to be identical. Bio-tracking studies revealed that viral loads of LcPV1 drop significantly in L. candicans but not in H. mesophaeum within four years period. The physical proximity of the mycelial networks of both fungal specimens implied the occurrence of a virus transmission event with unknown mechanism. Nature of this virus transmission was discussed in relation to transient interspecific mycelial contact hypothesis.

Keywords: Ectomycorrhizal fungus; Interspecific virus transmission; Mycovirus; Partitiviruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fungal Viruses* / genetics
  • Hebeloma*
  • Mycorrhizae*
  • Phylogeny
  • RNA Viruses* / genetics

Supplementary concepts

  • Hebeloma mesophaeum