Rediscovering parsley virus 5: characterizing a known virus with an unknown genome

Parsley virus 5 (PaV5) is a plant virus that has been known for several decades and is associated with infections of parsley and parsnips. Despite its early identification and potential classification within the Potexvirus genus, family Alphaflexiviridae, its full-length sequence has not been determined so far. This lack of sequence data presents a significant gap in understanding the virus’ biology and limits its detection tools. Investigating and sequencing this “known unknown” virus is necessary for accurate diagnosis and understanding its epidemiology. In this study we revisited PaV5, uncovering and characterizing its full genome using high-throughput sequencing (HTS). Phylogenetic analysis revealed that the polymerase and the capsid protein of PaV5 are closely related to that of a different potexvirus: cnidium virus X. This study confirms that PaV5 is a member of the genus Potexvirus, as previous morphological and serological studies showed. We propose “Potexvirus pentapetroselii” as its binomial species name.