Natural deletion is not unique in the coat protein (CP) of recombinant <i>Plum pox virus</i> (PPV) isolates in Hungary

Abstract

Three Plum pox virus (PPV) isolates (Soskut1, Godollo2, Szigetcsep1), collected from apricot (Prunus armeniaca L.) trees in Hungary in 2008, were characterized in this study by sequence analysis of the RT-PCR amplified 3’ part of the viral genome spanning the 3’ part of the NIb gene the complete CP gene and the 3’UTR [3’NIb–CP–3’UTR] and also by restriction analysis of the PCR products derived from the 3’ part of the P3, the complete 6K1 and the 5’ end of the CI genes [3’P3–6K1–5’CI]. Phylogenetic analysis of the 3’NIb–5’CP region showed that one isolate (Godollo2) could be classified as a member of the PPV-Rec group, while the other two (Soskut1 and Szigetcsep1) belonged to PPV-D isolates. In the case of the recombinant Godollo2 isolate a 33-nucleotide (nt) in frame natural deletion was detected in the 5’ part of the CP gene during the sequence analysis of the cDNA fragment corresponding to the 3’NIb–CP–3’UTR region. Currently we have reported on another Hungarian PPV-Rec isolate (PPV-B1298) collected from plum that also had a shorter CP gene bearing a much larger 135-nt in frame natural deletion at a similar position to that of the Godollo2. The PPV-D type Soskut1 isolate showed an atypical restriction pattern in the 3’P3–6K1–5’CI region using EcoRI and DdeI endonucleases, respectively. Nucleotide sequence analysis of this region indicated that its unusual pattern is as a result of a point mutation affecting the EcoRI restriction site.

Keywords: Plum pox virus, PPV, natural CP deletion mutant, EcoRI restriction site