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Plant viruses cause significant global agricultural losses estimated at $60 billion annually, yet direct chemical controls are currently unavailable. This presentation explores the role and diversity of antiviral Jacalin-like lectin (JAL) genes. JAX1 provides resistance against potexviruses by directly binding to the viral RNA-dependent RNA polymerase (RdRp). This interaction prevents the assembly of the large (>1000kDa) premature replication complex (PreVRC), effectively inhibiting virus replication at the cellular level. Phylogenetic analysis reveals that JAX1 orthologs are widely conserved across the Brassicaceae family. We demonstrate that variations in the existence, expression, and activity of these orthologs are key determinants of potexvirus host specificity, contributing to the family-wide "non-host" status of Brassicaceae. Furthermore, we highlight the agricultural potential of JAL genes: transgenic tomato lines expressing JAX1 show robust, broad-spectrum resistance to multiple strains of the devastating pepino mosaic virus (PepMV). Finally, we report on the isolation of another antiviral Jacalin-like lectin, JAX2. These findings underscore the importance of the jacalin gene family as a critical genetic resource for developing virus-resistant crops.