Inhibition effects of RNAi mediated by dsRNA-endoPGs and dsRNA-RMK1 on tobacco target spot disease

To safely and effectively prevent and control tobacco target spot disease, endo polygalacturonases (endoPGs) and MAP kinases of the tobacco target spot pathogen (Rhizoctonia solani YC-9)were used as the targets to design and synthesize dsRNA-endoPGs and dsRNA-RMK1 by RNA interference technology. The control effects of dsRNA-endoPGs and dsRNA-RMK1 on tobacco target spot were analyzed by spraying on tobacco leaves in vitro and tobacco plants in the field. The results showed that 7 d after spraying dsRNA-endoPGs and dsRNA-RMK1 on tobacco leaves in vitro, the inhibition rates of tobacco target spot lesions were 62.10% and 60.00%, respectively. After spraying dsRNA-endoPGs or dsRNA-RMK1 on the leaves of tobacco plants in field trials once every 7 d and 3 times in total, the relative control efficacies on tobacco target spot 7, 14, 21 d after the first spray were all above 50%.