In the systemic leaves of RCY1‐HA plants with local CMV(Y) infection AGO2 was expressed also in the absence of challenge (CMV(Y)+, WS−; yellow column), but this response was lower than in the systemically challenged RCY1‐HA plants with local infection (CMV(Y)+, WS+; yellow column) (Figure 3). This evidence concerns the gene AGO2 and infection.