JAK/STAT signaling pathway is involved in antibacterial immunity in the green peach aphid Myzus persicae (Sulzer)

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway within the innate immune system plays a crucial role in defending insects against bacterial, fungal, and viral pathogens. In this study, we identified and cloned five key genes of this signaling pathway in Myzus persicae: MpDome-1, MpDome-2, MpJak, MpStat92E-1, and MpStat92E-2. Our results illustrated that these genes were highly expressed in first, second and third-instar nymphs. Tissue-specific expression analysis revealed that the five genes were predominantly expressed in the gut. Upon bacterial challenge, particularly with Staphylococcus aureus, the expression levels of all five genes were significantly upregulated. Additionally, Escherichia coli infection significantly upregulated the expression levels of MpDome-1 and MpDome-2, while MpJak, MpStat92E-1 and MpStat92E-2 were weakly upregulated. Functional analysis through RNA interference-mediated knockdown of these target genes revealed a significant increase in mortality following infection with E. coli and S. aureus compared with the control group. These findings suggest that the JAK/STAT signaling pathway is crucial for immune defense against bacterial infections in M. persicae.