Characterization of a novel single-stranded RNA mycovirus related to invertebrate viruses from the plant pathogen Verticillium dahliae
Fungal viruses, also known as mycoviruses, are widespread in all major groups of fungi. Mycoviruses from plant pathogens can reduce the virulence of their host fungus and have therefore potential as biological control agents. This has spurred the identification of novel mycoviruses in plant pathogens, research which is greatly contributing to our understanding of these organisms. In this work, we report the characterization of a novel monopartite mycovirus from Verticillium dahliae, the main causal agent of Verticillium wilt. This novel mycovirus, which we termed Verticillium dahliae RNA virus 1 (VdRV1), was identified in three different isolates of V. dahliae collected in olive growing areas of the Guadalquivir valley, southern Spain. We determined that the VdRV1 genome is a positive (+) single-stranded (ss) RNA, 2631 nucleotides in length, containing two open reading frames. VdRV1 showed few similarities with known mycoviruses, only with a group of unassigned (+) ssRNA mycoviruses which are related to plant viruses classified within the family Tombusviridae. However, phylogenetic analysis revealed that VdRV1 and the unassigned (+) ssRNA mycoviruses have a closer relationship with recently reported invertebrate viruses. This result indicates that as more viral sequences become available, the relationships of mycoviruses with viruses from other hosts should be reexamined. Additionally, the work supports the hypothesis of a heterogeneous origin for mycoviruses.
This research was supported by Grants AGL2013-48980-R and AGL2016-80048-R from the Spanish Ministry of Economy and Competitiveness, co-funded by the European Union (FEDER funds). The authors would like to thank Dr Scott E. Gold for his editorial review of this manuscript.
Compliance with ethical standards
Financial support for this study was provided by the Spanish Ministry of Economy and Competitiveness through Grants AGL2013-48980-R and AGL2016-80048-R, co-funded by the European Union (FEDER funds).
Conflict of interest
The authors declare no conflict of interest.
This article does not contain any studies of animals performed by any of the authors.
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