ROS accumulation and antiviral defence control by microRNA528 in rice

Several studies have implicated microRNAs in plant defenses against pathogens. Wu et al. previously showed that virus resistance is facilitated by the interaction of viral-inducible AGO18 (which is cleavage-inactive) and rice miR528. In this work, they identified the role of miR528 in viral resistance. Rice susceptibility to rice-stripe virus is positively correlated with miR528 expression level, indicating that miR528 negatively impacts defense.  The authors showed that ascorbate oxidase (AO) is a direct target of miR528, and also that AO contributes to reactive oxygen (ROS) production. Therefore, when AGO18 binds miR528, ROS production and viral resistance are elevated. Nature Plants  10.1038/nplants.2016.203