|Yao, Xiaolong - The Ohio State University|
|Han, Junping - The Ohio State University|
|Qu, Feng - The Ohio State University|
|Lewis Ivey, M - The Ohio State University|
Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2017
Publication Date: 2/1/2018
Citation: Yao, X., Han, J., Domier, L.L., Qu, F., Lewis Ivey, M.L. 2018. First report of grapevine red blotch virus in Ohio vineyards. Plant Disease. 102(2):463.
Interpretive Summary: Grapevine red blotch-associated virus (GRBaV) is a recently discovered virus thought to be responsible for grapevine red blotch disease. The disease reduces the profitability of vineyards by reducing the quantity and quality of fruit harvested and the longevity of grapevines. Since the discovery of the disease eight years ago in California, GRBaV isolates have been recovered from symptomatic grapevines across the continental United States and from several other countries. This study compared the genetic variability of six new isolates of GRBaV from Ohio to isolates from other locations in the USA. The analyses showed that North American GRBaV have very low levels of genetic variability, which suggests that the vegetative propagation used in establishing vineyards could be important for the dissemination of the virus. These studies will be of interest to scientists who are studying the epidemiology and control of grapevine-associated viruses.
Technical Abstract: Grapevine red blotch-associated virus (GRBaV) is a recently discovered geminivirus likely responsible for one type of grapevine decline disease. Since its discovery five years ago, close to 30 GRBaV isolates have been identified across continental United States and from several other countries. The sequences of these isolates make up an ideal dataset for a comparative analysis of GRBaV genome diversity, as well as the level of variability of GRBaV-encoded proteins. In the current study, we report the identification of six new GRBaV isolates from Ohio, USA, and their incorporation in an exhaustive analysis that compared the full length genome sequences of all available GRBaV isolates, and the amino acid sequences of capsid (CP) and C1 proteins they encode. These comparisons revealed that GRBaV CPs exhibit substantially lower levels of sequence variation than either C1 proteins or the entire genomes, hence is probably under negative selection to preserve certain crucial functions. The highly conserved nature of GRBaV CPs provides a convenient means for virus detection, but cautions against the use of CP sequences to interpret the evolutionary history of this virus.