|Thannhauser, Theodore - Ted|
|Cox Foster, Diana|
Submitted to: Journal of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2007
Publication Date: 1/14/2008
Citation: Yang, X., Thannhauser, T.W., Burrows, M.E., Cox Foster, D., Gildow, F., Gray, S.M. 2008. Coupling genetics and proteomics to identify aphid proteins associated with vector-specific transmission of Polerovirus (Luteoviridae). Journal of Virology. 82:291-299. Interpretive Summary: Barley yellow dwarf is economically the most important virus disease of cereal crops. Related viruses cause significant economic losses in potato, soybean, sugar beet and vegetable crops. All these viruses are dependent upon aphid vectors to move between hosts and there are limited disease control options that have proven effective. Our studies have focused on the mechanisms by which aphids can efficiently pick up and transmit virus from an infected plant to a healthy plant. If transmission can be eliminated or reduced, disease epidemics can be slowed or prevented. This work describes the identification of specific proteins that are found only in aphids that are able to transmit the viruses. These proteins are absent in other aphids of the same species that are unable to transmit the virus. Two of these proteins have similar properties to other proteins that function to transport large molecules (such as viruses) into and through cells, in this case insect tissues. Furthermore, these proteins are capable of specifically recognizing and binding to virus particles, a property that would be expected of proteins directly involved in virus transmission. These are the first aphid proteins identified that can be directly correlated with the ability of an aphid to transmit viruses. They may provide specific targets for the disruption of the virus transmission process and the development of novel disease control strategies.
Technical Abstract: Cereal yellow dwarf virus-RPV (CYDV-RPV) is transmitted specifically by the aphids Rhopalosiphum padi and Schizaphis graminum in a circulative nonpropagative manner. The high level of vector-specificity results from the vector aphids having the functional components of the receptor-mediated endocytotic pathways to allow virus to transverse the gut and salivary tissues. Studies of F2 progeny from crosses of vector and nonvector genotypes of S. graminum showed that virus transmission efficiency is a heritable trait regulated by multiple genes acting in an additive fashion and that gut and salivary associated factors are not genetically linked. Utilizing two dimensional difference gel electrophoresis (DIGE) to compare proteomes of vector and nonvector parental and F2 genotypes, four aphid proteins (S4, S8, S29, and S405) were specifically associated with ability of S. graminum to transmit CYDV-RPV. The four proteins were co-immunoprecipitated with purified RPV, indicating that the aphid proteins are capable of binding to virus. Analysis by mass spectrometry identified S4 as a luciferase and S29 as a cyclophilin, both of which have been implicated in macromolecular transport. Proteins S8 and S405 were not identified from available databases. Study of this unique genetic system coupled with proteomic analysis indicated that these four virus-binding aphid proteins were specifically inherited and conserved in different generations of vector genotypes and suggests that they play a major role in regulating polerovirus transmission.