Recently, the Plant Protection Team from the Institute of Tobacco Research, Chinese Academy of Agricultural Sciences has made progress, revealing that insect virus infection facilitate the transmission of plant virus by aphid. The related findings have been published in New Phytologist.

The evolutionary relationships between plant viruses, their insect vectors and host plants are well studied, however the roles of insect viruses in the system have largely been neglected. Green peach aphid (Myzus persicae) vectors several agriculturally-important plant viruses (e.g. Potato virus Y, PVY) and they can also be infected by insect viruses (e.g. Myzus persicae nicotianae densovirus, MpnDV), which makes it an ideal model system to address this knowledge gap. Herein, we found that the MpnDV increased the activities of its host, promoting population dispersal, and leading to significant proliferation in tobacco plants by significantly enhancing the titer of the sesquiterpene (E)-β-farnesene (EβF) via up-regulation of expression levels of the MpFPPS1 gene. Although the acquirement of PVY was the same in MpnDV-positive and -negative individuals, the proliferation and dispersal of MpnDV-positive individuals were faster than MpnDV-negative ones on PVY-infection tobacco plants, which promoted the transmission of PVY. Taken together, for the first time, we have shown that an insect virus may facilitate the transmission of a plant virus by enhancing the locomotor activity and population proliferation of their insect vector. These findings provide novel opportunities for controlling insect vectors and plant viruses, which can be used in the development of novel management strategies.

This work was funded by Major special projects for green pest control and the Agricultural Science and Technology Innovation Program.