First report of Verbena latent virus infecting giant goldenrod in Belgium

Giant goldenrod (Solidago gigantea) was initially introduced from North America as an ornamental plant and is now considered highly invasive in Europe, negatively impacting native plant species. In summer 2023, a virome survey in Belgium collected asymptomatic goldenrod samples from 10 sites and detected Verbena latent virus (VeLV, Carlavirus, Betaflexiviridae) through high-throughput sequencing (HTS) techniques. VeLV was already detected in other plant species but its genome was not sequenced until the present work. The study also identified two novel plant-associated virus-like sequences and sequences of unknown mycoviruses in the samples. Further confirmation of VeLV infection was achieved through RT-PCR and Sanger analysis, with subsequent comparison to known VeLV sequences and the identification of one site infected in Belgium. This discovery underscores the importance of understanding VeLV biology and symptomatology, as VeLV presents a wide host range from in at least three plant families, the broad transmission profile of carlaviruses and their potential pathogenicity in single infection or mixed infection. To our knowledge, this is the first report of VeLV infecting S. gigantea worldwide. As giant goldenrod is widespread in Europe, it may serve as a significant asymptomatic reservoir for VeLV.