Genome sequence of a novel partitivirus identified from the oomycete Pythium nunn.

The mycoparasitic oomycete Pythium nunn isolate UZ415 contains two double-stranded RNAs (dsRNAs) of different sizes. The 1707-nt dsRNA1 and the 1475-nt dsRNA2 potentially encode an RNA-dependent RNA polymerase (RdRp) and a coat protein (CP), respectively, with sequence similarity to the RdRp and CP of gammapartitiviruses (< 57% and < 36%). Phylogenetic analysis of the deduced RdRp amino acid sequences indicated that the virus identified from P. nunn is classifiable as a distinct member of the genus Ganmmapartitivirus in the family Partitiviridae. This virus isolate is hereby named Pythium nunn virus 1 (PnV1).