## 2 Results
### RNAi Effect of DaAST and DaJHAMT
#### 2.5.3 The Effects of RNAi of dsAST and dsJHAMT on the Development of _D. armandi_  
After the larvae were treated with engineered bacteria, the survival rates of the control (vector control), dsAST and dsJHAMT groups were 13.33%, 20.00% and 10.00%, respectively, on Day five (Figure 8A). The Kaplan-Meier method (log rank (Mantel-Cox)) was used to analyze the survival rates. There was no significant difference in the survival rates of the dsAST and dsJHAMT groups compared with the control group (dsAST: \(\chi^{2}\) = 0.037, df = 1, \(p\) = 0.847; dsJHAMT: \(\chi^{2}\) = 0.010, df = 1, \(p\) = 0.919). After the pupae were treated with engineered bacteria, the survival rates of the control (vector control), dsAST and dsJHAMT groups on Day nine was 60.00%, 24.00%, and 48.00%, respectively. (Figure 8B). Survival in the dsAST group was 36% lower than in the control group (\(\chi^{2}\) = 5.083, df = 1, \(p\) = 0.024) whereas there was no difference in survival between the dsJHAMT and control groups (\(\chi^{2}\) = 0.651, df = 1, \(p\) = 0.52). In addition to the larval and pupal survival rate, the effects of dsAST and dsJHAMT on the emergence rate of pupae and the rate of abnormal morphology in emergent adults were also analyzed. The emergence rates of the dsAST and dsJHAMT groups were both 52.00%. These rates were significantly lower than the emergence rate of the control (vector control), which was 72.00% (\(F\) = 17.0, df = 3, \(p\) = 0.001) (Figure 8C). The abnormal morphology rates in emergent adults of the control (vector  
Figure 6: The qRT-PCR analysis of _DaAST and DuJHAMT_ gene transcript patterns in _D. armandi_ 24 and 72 h after dsRNA injection. (**A**) The qRT-PCR analysis of _DaAST_ transcript pattern; (**B**) the qRT-PCR analysis of _DaJHAMT_. The standard errors of the means of three biological replicates are represented by error bars. Different letters above the bars indicate a significant difference (One-way ANOVA, \(p\) < 0.05, with [PERSON]’s test of multiple comparisons).  
control) and dsJHAMT groups were 16.39% and 15.45%, respectively. These rates were significantly lower than that of the dsAST groups, which was 54.46% (\(F\) = 38.2, df = 3, \(p\) < 0.001) (Figure 8D). Taken together, these data show that _DaAST_ and _DaJHAMT_ gene silencing was able to disturb the growth and development of _D. armandi_, and that dsAST had the greatest interference effect.  
Figure 7: Knockdown of _DaAST_ and _DaJHAMT_ affected JH biosynthesis and the mevalonate pathway. The larvae, pupae and emergent adults were allowed to ingest DEPC treated water (negative control), dsAST or dsJHAMT for three days. The expression levels of _DaAST_, _DaJHAMT_ and mevalonate enzyme-encoding genes were measured. (**A**) Knocked down _DaAST_ in larvae, (**B**) knocked down _DaAST_ in pupae, (**C**) knocked down _DaAST_ in female adults, (**D**) knocked down _DaAST_ in male adults, (**E**) knocked down _DaJHAMT_ in larvae, (**F**) knocked down _DaJHAMT_ in pupae, (**G**) knocked down _DaJHAMT_ in female adults and (**H**) knocked down _DaJHAMT_ in male adults. The columns represent averages with vertical lines indicating SE. Asterisks denote significant differences (unpaired \(t\)-test; \({}^{\star}\)\(p\) < 0.05, \({}^{\star\star}\)\(p\)\(\leq\) 0.01, \({}^{\star\star\star}\)\(p\)\(\leq\) 0.001).