Infection efficiency of ago1 single, double or triple mutants by TuMV-GFP was similar to that of wild type plants (Fig. 2A panels II and III), and infection efficiency of ago1–27 ago2–1 double and ago1–27 ago2–1 ago10–5 triple mutants by TuMV-AS9-GFP was similar to that of dcl2–1 dcl3–1 dcl4–2 plants used as susceptible control (Fig. 2A panel II). The gene discussed is AGO2; the disease is infection.