Dihydromyricetin Inhibits East Asian Passiflora Virus Replication by Targeting the Coat Protein and Modulating the Flavonoid Pathway.

Cultivation of passion fruit (Passiflora edulis) is significantly impacted by East Asian Passiflora virus (EAPV). This study investigates the antiviral potential of the natural flavonoid dihydromyricetin (DHM) in targeting the EAPV coat protein (CP). Molecular docking analyses revealed that DHM exhibits a strong affinity for EAPV-CP, a finding corroborated by microscale thermophoresis (KD = 3.48 ± 2.18 μM). In vivo experiments demonstrated that DHM treatment resulted in a reduction of CP transcription by up to 16-fold in tobacco leaves and 2-fold in passion fruit leaves after 18 days. Transcriptomic analysis indicated that DHM application significantly modified host gene expression, particularly through the upregulation of differentially expressed genes associated with flavonoid biosynthesis and plant defense signaling pathways. Metabolomic profiling revealed an enrichment of flavonoid-related metabolites. Furthermore, an integrative analysis identified three gene modules that exhibited strong correlations with flavonoid metabolism. These findings suggest that DHM inhibits EAPV by targeting the viral coat protein and enhancing the host-derived flavonoid-induced resistance. Consequently, DHM emerges as a novel and sustainable antiviral agent for managing Potyvirus infections in agricultural crops.