|JARUGULA, SRIDHAR - The Ohio State University|
|CHARLESWORTH, STEVEN - The Ohio State University|
|QU, FENG - The Ohio State University|
Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2016
Publication Date: 5/28/2016
Publication URL: https://handle.nal.usda.gov/10113/63349
Citation: Jarugula, S., Charlesworth, S., Qu, F., Stewart, L.R. 2016. Soil-borne wheat mosaic virus infectious clone and manipulation for gene-carrying capacity. Archives of Virology. 161:2291-2297.
Interpretive Summary: Soilborne wheat mosaic virus (SBWMV) is a wheat-infecting virus with potential for development for beneficial research purposes such as gene expression or gene knockdown by virus-induced gene silencing (VIGS). Virus-based "vectors" for gene expression and silencing knockdown have proved very useful in understanding basic biology of dicotyledonous model and agricultural plants, but fewer viral vectors are available for monocotyledonous plants including the important grasses rice, wheat, corn, oats, and barley. To address this, we developed SBWMV for study and investigated its potential as a vector for monocots. Replacing a portion of the virus genome with plant sequences showed that insertions were much more stable than typical for virus-based vectors. However, desired gene knockdown was observed only in a dicotyledonous SBWMV model host and not in wheat. We conclude that while SBWMV may have utility, further work is needed to identify sequence insertion sites and to understand the different reponses of the two different hosts.
Technical Abstract: Soilborne wheat mosaic virus (SBWMV) is a bipartite single stranded positive sense RNA virus with rigid-rod shaped virions. Taxonomically the virus is in the family Viragviridae, as are commonly used gene silencing or expression viral vectors, Tobacco rattle virus (TRV) and Barley stripe mosaic virus (BSMV). In this study, an agrobacterium binary vector based full-length infectious cDNA clone of SBWMV was developed. The cloned virus can infect and be scaled up in the dicotyledonous host Nicotiana benthamiana for subsequent infection of the monocotyledonous host wheat (Triticum aestivum, L.). Virus-induced gene silencing (VIGS) studies through insertion of sequences in multiple regions of virus genome showed induction of VIGS only in the dicot host, N. benthamiana with cDNA clones with insertions in CP-readthrough (CPRT) region. Similar studies for gene expression using GFP found ideal sites only for localized expression in infiltrated leaves of N. benthamiana. One of the useful features observed from current study is that the virus clones with deletions or insertions replacing major portion of the CPRT region are infectious and stable for at least 47 days in both the hosts, in contrast to rapid deletions of the CPRT in mechanically transmitted wild type clones. The SBWMV VIGS system highlights the potential differences between monocot and dicot RNA silencing mechanism. Identification of factors that limit VIGS in wheat could improve the utility of the virus as a useful gene silencing vector in monocot hosts.