Molecular Characterization of a Novel Ourmia-Like Virus Infecting Phoma matteucciicola

Here, we report a novel (+) ssRNA mycovirus, Phoma matteucciicola ourmia-like virus 1 (PmOLV1), isolated from Phoma matteucciicola strain LG915-1. The genome of PmOLV1 was 2603 nucleotides long and contained a single open reading frame (ORF), which could be translated into a product of RNA-dependent RNA polymerase (RdRp) by both standard and mitochondrial genetic codons. Cellular fractionation assay indicated that PmOLV1 RNAs are likely more enriched in mitochondria than in cytoplasm. Phylogenetic analysis indicated that PmOLV1 is a new member of the genus Penoulivirus (recently proposed) within the family Botourmiaviridae.

RNA 2 of Citrus psorosis virus is of negative polarity and has a single open reading frame in its complementary strand

Citrus psorosis virus (CPsV) causes a citrus disease occurring worldwide. Isolate CPV 4 has a genome with three single-stranded RNAs. The complete sequence of RNA 2 (1643 nucleotides) is reported here. Northern blot hybridization with strand-specific probes showed that most of the encapsidated RNA 2 is of negative polarity, although a small amount of the complementary strand may also be present in particles. The RNA 2 complementary strand contained a single open reading frame encoding a protein of 476 amino acids, which includes a motif resembling a nuclear localization signal. The sequence of this putative protein shows no significant similarity to any other in the databases. In the 3′-terminal untranslated region there is a putative polyadenylation signal. No subgenomic RNAs derived from RNA 2 were detected.