Fig. 3

A recent reported example of PSM-mediated plant–insect-virus interactions. During the airborne defense mechanism, VOC-emitter plants sense aphid sap-sucking action, triggering the biosynthesis of SA. The NAC2-SAMT1 module is then activated to produce volatile MeSA. Receiver plants in the vicinity perceive MeSA and convert it into SA through the action of SABP2. SA functions as a cue, initiating the NAC2-SAMT1 module in the receiver plants, consequently eliciting a defense response against both aphids and viruses. At the counterdefence mechanism, the aphid-transmitted virus CMV, employ their helicase-containing viral protein (e.g., CMV1a) to subcellularly re-localize and destabilize NAC2. This manipulation suppresses NAC2-mediated airborne defense, facilitating aphid propagation and virus transmission. As a result, plants become less repellent to aphids, generating a more favorable environment for aphid survival, infestation, and subsequent viral transmission. The figure is created with biorender.com and the illustration is adapted from the recent work of (Gong et al. 2023)