Viral suppressors of RNA silencing

The suppression of RNA silencing by plant viruses represents a viral adapta tion to a novel host antiviral defense. Three types of viral suppressors ha ve been identified through the use of a variety of silencing suppression as says. The first two types of suppressor are capable of a complete or partia l reversal of preexisting RNA silencing; the third type does not reverse RN A silencing but can instead prevent its systemic signaling.