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Viruses are common in fungi and oomycetes and some of these viruses share sequence identities with plant viruses belonging to different families and genera. Replication of the plant virus tobacco mosaic virus has been demonstrated in the phytopathogenic fungi Colletotrichum acutatum, C. clavatum and C. theobromicola and more recently, infection of cucumber mosaic virus has been reported in Rhizoctonia solani isolated from potato plants in the field. Here we show that artichoke mottled crinkle virus, potato virus X, potato virus Y and cucumber mosaic virus plus its satellite RNA can replicate and persist in C. acutatum at least through the first subculture and that artichoke Italian latent virus, artichoke mottled crinkle virus, potato virus X, potato virus Y, tobacco mosaic virus and cucumber mosaic virus plus its satellite RNA can replicate and persist in Phytophthora infestans at least through the first subculture. These observations suggest that, unlike in plants, there may be a different basis for host-virus specificity in plant virus infection in filamentous fungi and oomycetes.

International audience; Complete genomic sequences of Artichoke latent virus (ArLV) have been obtained by classical or high-throughput sequencing for an ArLV isolate from Italy (ITBr05) and for two isolates from France (FR37 and FR50). The genome is 8,278 to 8,291 nucleotides long and has a genomic organization comparable with that of Chinese yam necrotic mosaic virus (CYNMV), the only macluravirus fully sequenced to date. The cleavage sites of the viral polyprotein have been tentatively identified by comparison with CYNMV, confirming that macluraviruses are characterized by the absence of a P1 protein, a shorter and N-terminally truncated coat protein (CP). Sequence comparisons firmly place ArLV within the genus Macluravirus, and confirm previous results suggesting that Ranunculus latent virus (RALV), a previously described Macluravirus sp., is very closely related to ArLV. Serological relationships and comparisons of the CP gene and of the partial RaLV sequence available all indicate that RaLV should not be considered as a distinct species but as a strain of ArLV. The results obtained also suggest that the spectrum of currently used ArLV-specific molecular hybridization or polymerase chain reaction detection assays should be improved to cover all isolates and strains in the ArLV species.