Location: Horticultural Crops ResearchTitle: Evidence of sympatric speciation of elderberry carlaviruses Author
Submitted to: Virus Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/23/2016
Publication Date: 2/16/2016
Citation: Ho, T., Keller, K.E., Postman, J.D., Martin, R.R., Tzanetakis, I.E. 2016. Evidence of sympatric speciation of elderberry carlaviruses. Virus Research. 215:72-75. doi: 10.1016/j.virusres.2016.01.017. Interpretive Summary: Using high throughput sequencing five carlaviruses were characterized from elderberry from the National Clonal Germplasm Repository in Corvallis, Oregon and they are tentatively named as elderberry virus A-E (EVA-EVE). The five viruses divided into two broad groups with EVA, EVB and EVD sharing a common ancestor and EVC and EVE evolved from a different ancestor. Since the plants were at the repository for a long period of time it is not possible to determine if the plants were infected when they were brought into the repository or if there was virus transmission at the repository. Additionally, plants were infected with multiple viruses so it is not possible to determine the impact of individual viruses. Detection primers were developed that can differentiate the five viruses and additional primers that can detect all five viruses and should detect all carlaviruses. The broad spectrum primers should be useful for certification and quarantine programs. Sequence analysis of the carlavirus conserved sequences suggests that recombination has played a significant role in the evolution of these viruses.
Technical Abstract: Five new carlavirus species infecting elderberry were characterized and tentatively named as elderberry virus A-E (EVA-EVE). The genome organization of the viruses ranges between 8,540-8,628 nucleotides, excluding the polyadenylated tail. EVA, EVB and EVD share a common ancestor as do EVC and EVE, indicating that speciation may be sympatric with all viruses having emerged in elderberry. Analyses of the carlavirus conserved domains indicate that the 2-oxoglutarate and the Fe(II)-dependent oxygenase motif are reliable indicators of virus phylogenetic placement and recombination plays a major role in evolution of the genus. A universal assay that detects all the elderberry carlaviruses and potentially all members of the genus has been developed, a tool that can be used for research and regulatory purposes as elderberry cultivation is rapidly expanding to new areas were the viruses may be absent.