Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2010
Publication Date: 4/1/2010
Citation: Edwards, M.C., Weiland, J.J. 2010. First Infectious Clone of the Propagatively Transmitted Oat Blue Dwarf Virus. Archives of Virology. 155(4):464-471
Interpretive Summary: Most viruses are not capable of infecting both plants and insects, but Oat blue dwarf virus (OBDV) can infect both plants and the aster leafhopper that transmits the virus from plant to plant. Plant viruses capable of infecting their insect vectors are commonly referred to as being propagatively transmitted, since they propagate in their insect hosts. OBDV is a relatively small virus and is limited to the phloem, or food-conducting tissues of infected plants. We have developed complete clones of OBDV from which we can transcribe infectious viral RNA – the first such clones for any propagatively transmitted plant virus. Prior to clone construction, the sequence of the ends of the viral genome was determined and confirmed to be the same as reported previously. Using a pin inoculation technique, we were able to infect maize seeds with the cloned virus. Subsequently, aster leafhoppers successfully transmitted the cloned OBDV to oats and barley after feeding on detached, infected maize leaves. Infectious clones of propagatively transmitted viruses will be valuable in examining the interaction of these viruses with their insect and plant hosts.
Technical Abstract: Oat blue dwarf virus (OBDV) is a relatively small, phloem-limited marafivirus that replicates in its leafhopper vector. We have developed complete cDNA clones of OBDV from which infectious transcripts may be derived – the first such clones for any propagatively transmitted plant virus. Prior to clone construction, the reported sequence of the 5’ and 3’ ends was confirmed using 5’ RACE, primer extension, and ligation-anchored PCR. Using vascular puncture of maize seeds with capped transcripts, multiple clones were shown to be infectious at an average rate of 24.3% (range 14–36%). Aster leafhoppers successfully transmitted OBDV to oats and barley after feeding on detached, infected maize leaves. Proteins and RNAs consistent in size with those expected in OBDV infection were detected in young leaves via western and northern blotting, respectively. Infectious clones of propagatively transmitted viruses will be valuable in examining the interaction of these viruses with their insect and plant hosts.