Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 9/8/1997
Publication Date: N/A
Technical Abstract: The BYDV readthrough domain (RT) normally is a minor component of the virion, although it is not required for particle assembly. In a previous study, a BYDV mutant unable to translate RT was found to be not aphid transmissible. To identify regions of the RT that are involved in aphid transmission, a series of deletion mutants were constructed. None of the deletions reduced the accumulation of viral antigen in protoplasts, but deletions in the amino terminal half of the RT domain abolished aphid transmission. The nontransmissible viruses were however acquired by the aphid vectors and virus could move from the hindgut into the hemocoel. A mutant that did not translate the carboxyl terminal half of the RT domain was aphid transmissible, but symptoms on infected plants were attenuated. If the nontransmissible viruses were inoculated into plants via a novel trans-complementation assay with a movement defective virus, the deletion mutations were stable, but the plants did not show typical symptoms. This is the first definitive evidence that the carboxyl terminal portion of the BYDV RT domain is not required for aphid transmission.