# Proteomic Evaluation of Insecticidal Action of Phosphine on Green Peach Aphids, _Myzus persicae_
## 3 Results
### Proteomic Changes in M. persicae after PH\({}_{3}\) Treatment  
A total of 1692 proteins were identified in the PH\({}_{3}\)-treated and non-chemically treated _M. persicae._ Among them, 49 proteins were up- and down-regulated in the PH\({}_{3}\)-treated _M. persicae_, while 13 proteins were newly expressed or could not be detected after PH\({}_{3}\) treatment (Figures 4 and 5, Tables S3 and S4). Folds in expression levels of proteins identified in the PH\({}_{3}\)-treated _M. persicae_ varied widely and increases by at least 2-fold in comparison with that in the control were considered in this study. Some proteins with small increases were ignored in the study, even if they were statistically significant. Figure 4: _Cont._Figure 4: Proteins differentially expressed in adults of _Myzus persicae_ after phosphine treatment at the concentration of 0.5 mg/L for 4 h. CON; control treatment group, PH3; phosphine treatment group. Statistically difference was analyzed using _t_-test (_p_ < 0.05). *, <0.05; **, 0.01; ***, 0.001; ***, 0.0001. (**A**), proteins involved in energy metabolism, especially electron transport chain; (**B**), proteins involved in defense; (**C**), proteins involved in metabolism; (**D**), other proteins. Figure 5: _Cont._  
The primary changes in protein expression after PH\({}_{3}\) treatment in _M. persicae_ were found in the proteins of the respiratory system, including the upregulated NADH dehydrogenase (ubiquone) flavoprotein 1 (\(\times\)3.35-fold), cytochrome b-c1 complex subunit Rieske (\(\times\)0.53-fold), and the ATP synthase subunit g (\(\times\)0.54-fold) (Figure 4A). Cytochrome oxidase subunit II involved in ETC were also changed, but its change was not dramatic when compared to the control (\(\times\)0.70-fold) (Figure 4A). Some of the defense proteins, glutathione S-transferase-like (\(\times\)2.26-fold), lysozyme-like (\(\times\)3.14-fold), probable protein phosphatase 2C 6 (\(\times\)2.02-fold), and clusters of esterase E4-like isoform X1 were highly upregulated in PH\({}_{3}\)-treated _M. persicae_. However, multidrug resistance-associated  
Figure 5: Proteins differentially expressed in adults of _Myzus persicae_ after phosphine treatment at the concentration of 0.5 mg/L for 4 h. CON; control treatment group, PH3; phosphine treatment group. Statistically difference was analyzed using _t_-test (_p_ < 0.05). *, <0.05; **, 0.01; ***, 0.001; ***, 0.0001. (**A**), proteins classified in chromatin and histones; (**B**), proteins involved in transcription; (**C**), proteins involved in translation and post-translational modification; (**D**), proteins involved in signaling pathways; (**E**), other proteins. protein 4-like was found to be reduced in PH\({}_{3}\)-treated _M. persicae_ (Figure 4B). Interestingly, the expression of several carbohydrate-related proteins in response to the PH\({}_{3}\) treatment were also varied: galactokinase-like (\(\times\)2.2-fold), glucosidase 2 subunit beta-like (\(\times\)10.3-fold), and sugar transporter SWEET1-like (Figure 4C). On the contrary, histone H2A-like (\(\times\)0.19-fold), histone H2B-like (\(\times\)0.35-fold), histone H2A.V (\(\times\)0.032-fold), histone H3 (\(\times\)0.19-fold), which are highly alkaline proteins in eukaryotic cells, and circadian clock-controlled protein-like (\(\times\)0.17-fold) were dramatically down-regulated in PH\({}_{3}\)-treated _M. persicae_ (Figure 5A). Various regulatory proteins, myelin expression factor 2 (\(\times\)0.20-fold, Figure 5B), aspartate-tRNA ligase, cytoplasmic (\(\times\)2.18-fold, Figure 5C), ubiquitin-conjugating enzyme E2 (\(\times\)3.60-fold, Figure 5C), viz., type proton ATPase subunit d (\(\times\)2.38-fold, Figure 5D), lamin Dm0-like (\(\times\)0.52-fold, Figure 5D), ras-related protein Rab-5C (\(\times\)0.51-fold, Figure 5E), caspase-1-like (\(\times\)0.14-fold, Figure 5E), and cathepsin B (\(\times\)2.07-fold, Figure 5E) were differentially expressed in _M. persicae_ after PH\({}_{3}\) treatment. After PH\({}_{3}\) treatment, some regulatory proteins were newly produced, viz.