The dual edge of RNA silencing suppressors in the virus-host interactions.

RNA silencing (or RNA interference, RNAi) plays a key role in the plant antiviral defense. To facilitate infection, viruses encode suppressors of RNA silencing (VSRs) to counteract antiviral defense. In the co-evolutionary arms race between hosts and viruses, extreme viral accumulation does not benefit either hosts or viruses. During viral infection, antiviral silencing and VSRs have dual effects to maintain the balance between plant development and virus accumulation. Here, we summarize and discuss the multiple functions of the antiviral RNAi defense and VSRs, revealing the central hub regulators of VSRs in dynamically integrated connections between hosts and viruses.