Abstract

Cucumber mosaic virus (CMV) is the plant virus with the broadest host range. It is transmissible by more than 80 aphid species in a non-persistent manner. The CMV genome encodes five proteins, one of which is the 2b counter-defence protein, which interferes with host defensive signalling pathways. The ability of the CMV 2b protein to disrupt the host defensive network against CMV infection may influence the virus-plant-vector relationship. Previous work showed that on Nicotiana tabacum (tobacco) plants that were infected with a CMV mutant unable to produce the 2b protein (CMV∆2b), there were lower aphid survival and colony growth compared with the ones on wild-type CMV infected plants. This suggests that on tobacco, CMV infection may promote aphid performance. My project focuses on identifying CMV gene product(s) that elicit defensive responses in tobacco against aphids. Transgenic tobacco plants and aphids, Myzus persicae, are being generated to assess aphid-plant interactions in the presence or absence of one or more of CMV gene product(s).