Non-host resistance to plant viruses: What do we know?

Abstract

Non-host resistance (NHR) is a prevalent mode of plant defense against invading pathogens, including viruses. Being hard to circumvent, NHR has considerable potential to provide durable resistance against virus infection. This review systematically analyzes recent research findings demonstrating NHR mechanisms and chronologically enumerates the defense strategies contributing to NHR. Conventionally, the NHR mechanisms that operate by restricting viral entry and multiplication are termed “true NHR.” Here, we propose NHR mechanisms operating beyond viral multiplication in non-host plants as “apparent NHR.” This review elucidates both categories of NHR and provides insights into the mechanisms involved in NHR.