FIG 9.

Knockdown of DRB2 and RDR6 inhibits PPV-PVX synergism-induced SN. Wild-type N. benthamiana plants were infected by agroinfiltration using binary plasmid constructs expressing the indicated viruses. Pictures of the infected plants were taken at 14 dpi. Total RNAs were prepared from systemically infected plants at 7 dpi. Samples collected from three identically infected plants were pooled. Viral RNA levels and necrotic marker gene expression levels were analyzed by Northern blotting using the indicated radioactively labeled virus-specific and PR-1a-specific probes. The ethidium bromide (EtBr)-stained gel is shown as a loading control. The experiment was repeated three times with the same outcomes.