Pattern-triggered immunity (PTI) induction and transcriptional reprogramming in persistant allexivirus infection

In virus-plant interactions, one of the major mechanisms for plant antiviral immunity relies on RNA silencing, which is often suppressed by co-evolving viral suppressors, thus enhancing viral pathogenicity in susceptible hosts. However RNA silencing should not only be viewed as an antiviral mechanism that must be counteracted. In fact, many viruses encode weak or transiently active suppressors and probably do not use these viral proteins for control RNA silencing; for example, Shallot virus X (ShVX) do not code the active silencing suppressor and consequently use the another molecular mechanism to overcome the silencing immune barrier, establish the persistent infection and prevent catastrophic damage to its host. We hypothesized that this “non-suppressor” mechanism is the process of transcriptomic reprogramming (TRP) induced by the PTI (pattern-triggered immunity), the first layer of plant defence, which is triggered by specific recognition of conserved microbe- or pathogen-associated molecular patterns (MAMPs, or PAMPs, respectively) by pattern recognition receptors (PRRs) at the plasma membrane and the induction of defense signaling...