After silencing suppression: miRNA targets strike back.

Abstract

Within the continuous tug-of-war between plants and microbes, RNA silencing stands out as a key battleground. Pathogens, in their quest to colonize host plants, have evolved a diverse arsenal of silencing suppressors as a common strategy to undermine the host's RNA silencing-based defenses. When RNA silencing malfunctions in the host, genes that are usually targeted and silenced by microRNAs (miRNAs) become active and can contribute to the reprogramming of host cells, providing an additional defense mechanism. A growing body of evidence suggests that miRNAs may act as intracellular sensors to enable a rapid response to pathogen threats. Herein we review how plant miRNA targets play a crucial role in immune responses against different pathogens.