Metagenomics Study of the Commercial Tomato Virome Focused on Virus Species of Epidemiological Interest.

Plant viruses have detrimental effects on commercial tomato cultivation leading to severe economic consequences. Viral metagenomics studies provide the opportunity to examine in depth the virome composition of a sample set without any pre-existing knowledge of the viral species that are present. In the present study, 101 plant samples were collected from commercial greenhouses in 13 countries in Europe, Africa, Asia, and North America between 2017 and 2024. All samples were processed with the VLP enrichment protocol NetoVIR and the obtained data were analyzed with the ViPER pipeline. Forty-three eukaryotic viral species were identified, with a median identification of 2 species per sample. The most prevalent viral species were pepino mosaic virus (PepMV), tomato brown rugose fruit virus (ToBRFV), and southern tomato virus (STV). The obtained genome sequences were used to study the diversity and phylogeny of these viruses. The three genotypes identified for PepMV showed low diversity within each genotype (96.2-99.0% nucleotide identity). Low isolate diversity was also found for ToBRFV and STV. No significant association could be found between STV identification and the presence of symptoms, questioning the pathogenic potential of STV. Three other pathogenic viral species of particular interest due to their effects on tomato cultivation or recent emergence, namely tomato torrado virus (ToTV), tomato fruit blotch virus (ToFBV), and cucumber mosaic virus (CMV), were part of the virome with low prevalence. Our study provided a comprehensive overview of the analyzed samples' virome, as well as the possibility to inspect the genetic diversity of the identified viral genomes and to look into their potential role in symptom development.