Abstract

Cucumber mosaic virus (CMV) has the broadest host range of any plant virus, being able to infect over 1200 plant species. It is transmitted in a non-persistent manner by aphids and thus vector control is a key component of control strategies against this virus. The 2b protein of CMV is well characterised as a suppressor of plant defences against viral infection, including RNA silencing. It is a multifunctional protein that is also a symptom determinant as well as playing a crucial role in local and systemic movement of the virus through its hosts. Recent evidence from our lab suggests that there may be an additional role for 2b as a mediator of aphid transmission of CMV . A microarray study which used transgenic plants that constitutively expressed the 2b protein behind a 35S promoter indicated that 2b perturbs the methyl-jasmonate (MeJA) defence pathway in Arabidopsis thaliana. This pathway is highly conserved and is induced in response to wounding and herbivory. Upon induction of this pathway there is a significant upregulation of a large number of anti-insect genes and compounds. There is a large body of evidence that shows that MeJA treatment can induce aphid resistance in a variety of different species. Work presented here investigates the effect of CMV -infection and the 2b protein on aphids through monitoring of aphid feeding behaviour and performance and finds that CMV induces resistance to aphids in infected plants.