In N. benthamiana, infection of the meristems by potato virus X (PVX) is prevented by RDR6 (Schwach et al., 2005), and infection of the Arabidopsis meristems by TuMV is restricted by argonaute (AGO) proteins 1, AGO2 and AGO10 (Garcia‐Ruiz et al., 2015). The gene discussed is AGO2; the disease is infection.