Jasmonate signaling inhibition

Jasmonates (JA) are lipid-based phytohormones that give plants defenses against herbivorous insects. These insects are critical for the spread of plant viruses, which have evolved strategies to inhibit JA signaling to promote insect feeding and virus transmission.

Jasmonate signaling:

Insects feeding on a plant release jasmonate, which initiates the degradation of JAZ via the ubiquitin pathway. The host protein JAZ sequesters the transcription factor MYC2 in the cytoplasm, which is released upon proteolytic destruction of JAZ and migrates to the nucleus to activate host defense genes. This leads to the production of toxins and digestive inhibitors that repel insects from the plant.

This scenario is not advantageous for insect-borne plant viruses, as driving insects away from the infecting plant is detrimental to virus spread. Therefore, many plant viruses have evolved a mechanism that inhibits jasmonate signaling, making the infected plant attractive to insect vectors.