Fig 8. A schematic summary of the role of JNK pathway that modulates pea aphid immune signaling and is negatively regulated by miR-184.

The transcription factor AP-1 is activated through Jun and Fos that are phosphorylated by JNK. AP-1 upregulates PO activity, increases hemocytes phagocytosis, and upregulates genes expression for ROS detoxification. JNK expression is negatively regulated by miRNA-184a/b. Bacterial infection downregulates synthesis of miRNA-184, leading to deliverance of JNK pathway and activation of immune responses consequently, to protect pea aphid from infection and oxidative stress.