The viral transmission mode conditions host plant-mediated post-acquisition effects on vectors to allow optimal dissemination

Plant viruses can manipulate vectors feeding on infected hosts to enhance acquisition and hence transmission. We hypothesized that viruses likewise shape post-acquisition vector responses, when virus-carrying vectors reach out toward new plants, and that these effects depend on the virus’s transmission mode. We compared post-acquisition effects of two viruses with contrasting transmission strategies: turnip yellows virus (TuYV, persistent) and cauliflower mosaic virus (CaMV, non-persistent). Aphid motility, dispersal, survival, dry mass and lipid content were quantified. Metabolomic profiling of plants and vectors was conducted using mass spectrometry. Both viruses enhanced aphid dispersal after acquisition. However, only CaMV increased aphid motility. and triggered starvation stress, despite presumably higher nutritional value of infected plants. In contrast, TuYV induced only minimal metabolic and physiological disruptions in plants and aphids. Our results suggest that the transmission mode governs post-acquisition effects. While enhanced dispersal benefits all viruses, CaMV-induced starvation and motility likely accelerate dispersal during the limited time span vectors can transmit the virus. In contrast, TuYV hardly affected host plants and aphids, consistent with its reliance on long-lived competent vectors. This highlights the importance of transmission mode on vector manipulation and underscores post-acquisition vector behaviour and physiology as central components of virus transmission ecology.