Figure 2.

Effects of NlMLP silencing on BPH feeding and performance. A, The survival rates of BPH insects after injection were monitored daily. The survival rates of BPHs injected with dsMLP were reduced significantly compared with those of BPHs with no injection and those injected with dsGFP after 2 d of treatment (Student’s t test). C, BPHs with no injection; dsGFP, BPHs injected with GFP-dsRNA; dsMLP, BPHs injected with NlMLP-dsRNA. The experiment was repeated five times with 10 BPHs per replicate. Data represent means ± sd of five repeats. B, Honeydew excretion by BPH insects on filter paper. The intensity of the honeydew color and area of the honeydew correspond to BPH feeding activity. The experiment was repeated three times with 10 filter papers per replicate. Data represent means ± se of three repeats. Different letters above the bars indicate significant differences, as determined by Tukey’s honestly significant difference test (P < 0.05). C and D, BPH weight gain (C) and BPH weight gain ratio (D) of BPHs after injection with dsGFP or dsMLP. Data represent means ± se of five independent experiments with 10 BPHs per replicate. Different letters above the bars indicate significant differences, as determined by Tukey’s honestly significant difference test (P < 0.05). E, Survival rates of BPH insects feeding on NlMLP-dsRNA-transgenic plants (SG33-2) and wild-type plants (WT). The experiment was repeated five times with 20 BPHs per replicate. Data represent means ± sd of five repeats. Asterisks above the columns indicate significant differences compared with wild-type plants (*, P < 0.05 and **, P < 0.01, Student's t test). F, BPH weight after feeding for 10 d on NlMLP-dsRNA-transgenic plants (SG33-2) and wild-type plants. The experiment was repeated five times with 10 BPHs per replicate. Data represent means ± se of five repeats. The asterisk above one column indicates a significant difference compared with wild-type plants (*, P < 0.05, Student’s t test).