Sequence and genome organization of papaya meleira virus infecting papaya in Brazil

Papaya sticky disease (‘meleira’) was first observed in Brazil at the beginning of the 1980s. The disease is characterized by intense latex exudation from the fruit surface that becomes dark as it oxidizes, which makes it difficult to sell. The causal agent, which has been called papaya meleira virus (PMeV), has been identified as an isometric virus particle, approximately 50 nm in diameter, with a double-stranded RNA genome. Here, we report the first complete sequence and organization of the 8.7-kb viral dsRNA genome. Two ORFs coding for a putative coat protein and RNA-dependent RNA polymerase (RdRp) were predicted. In silico analysis revealed that the translated ORF2 contains the conserved domains characteristic of an RdRp protein (pfam02123:RdRP 4), which is a family that includes RdRps from members of the genera Luteovirus, Totivirus and Rotavirus. Evolutionary analysis with amino acid sequences with the RdRps from members of the family Totiviridae and some dsRNA viruses showed that PMeV RdRp did not root itself in any genus.