Journal Article
Molecular characterization of a polymycovirus in Leptosphaeria biglobosa
Nesma M. Samir; Jacob Locke-Gotel; Syun-Ichi Urayama; Adel A. El-Morsi; Ghada A. El-Sherbeny; Yongju Huang; Bruce D. L. Fitt; Hiromitsu Moriyama; Robert H. A. Coutts; Ioly Kotta-Loizou
Archives of Virology · Vol. 170, Issue 4 · 2025
Abstract
Leptosphaeria biglobosa is a phytopathogenic ascomycete of Brassica napus that causes phoma stem canker/blackleg. A new double-stranded RNA (dsRNA) mycovirus from this fungus has been fully characterized. The virus genome has five dsRNA segments, ranging in length from 1,180 bp to 2,402 bp. Each dsRNA has a single open reading frame flanked by 5′ and 3′ untranslated regions. The proteins encoded by dsRNAs 1 and 3, an RNA-dependent RNA polymerase (RdRP) and a methyltransferase, respectively, have significant similarity to those of Plasmopara viticola lesion associated polymycovirus 1. The proline-alanine-serine-rich protein encoded by dsRNA 5 is similar to that of Erysiphe necator associated polymycovirus 1. The proteins encoded by dsRNAs 2 and 4 have significant similarity to those of a mycovirus identified in Alternaria sp. FA0703. Phylogenetic analysis based on RdRP sequences showed that this virus clusters with members of the family Polymycoviridae . Based on these observations, this virus, which we have named "Leptosphaeria biglobosa polymycovirus 1", should be classified as a member of the family Polymycoviridae . This is the first report of a polymycovirus in L. biglobosa.