Manipulation of induced resistance to viruses

- Plants possess multiple inducible defenses against viruses.
- The best understood is RNA silencing but others inhibit replication and movement.
- It is now known that PAMP-triggered immunity inhibits infection by certain viruses.
- Endogenous defense signals and exogenous inducers continue to be discovered.
- Many synthetic compounds and beneficial microbes can act as resistance inducers.

Induced resistance against plant viruses has been studied for many years. However, with the exception of RNA silencing, induced resistance to viruses remains mechanistically less well understood than for other plant pathogens. In contrast, the induction processes involved in induced resistance, comprising basal resistance signaling, effector-triggered immunity, and phytohormone pathways, have been increasingly well characterized in recent years. This has allowed induced resistance to viruses to be placed in a broader conceptual framework linking it to other defense systems, which we discuss in this review. We also discuss the range of agents, including chemicals and beneficial microorganisms and application methods that can be used to induce resistance to viruses.