1Departments of Entomology, 407 Science II, Iowa State University, Ames, IA 50011, USA.
2Plant Pathology, 351 Bessey Hall, Iowa State University, Ames, IA 50011, USA.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
Rhopalosiphum padi virus (RhPV) is an icosahedral aphid virus with a 10 kb positive-sense RNA genome. The host, R. padi (the bird cherry-oat aphid), is the most common vector of Barley yellow dwarf virus, a serious disease of small grains, worldwide. We screened lepidopteran, dipteran and homopteran cell lines for susceptibility to RhPV following RNA transfection and observed cytopathic effects (CPE) in homopteran cell lines derived from the glassy winged sharp shooter, Homalodisca coagulata, and the corn leaf hopper, Dalbulus maidis. Infection, viral replication and production of virions was confirmed by northern blot hybridization, RT-PCR, western blot analysis and immunoelectron microscopy. Full-length cDNA clones of the RhPV genome were constructed. Inoculation of cell lines with RNA transcripts produced from one of the clones induced CPEs and generated virions visualized by immuno-electron microscopy. Virions were purified from transfected cells and fed to R. padi. Two weeks after acquisition, the aphids tested positive for RhPV by RT-PCR, western blot analysis and immuno-localization by light microscopy, in three out of three replicates. Further studies are underway to detect replication of transcripts in infected cells. Understanding replication of aphid viruses such as RhPV may lead to methods for controlling aphid pests.
