Biological and genomic characterization of a novel Tobamovirus infecting Hoya spp.

Authors: Adkins, Scott; D'ELIA, TOM - Indian River State College; FILLMER, KORNELIA - Indian River State College; PONGAM, PATCHARA - Indian River State College; BAKER, CARLYE - Florida Department Of Agriculture

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2018
Publication Date: 11/21/2018
Citation: Adkins, S.T., D'Elia, T., Fillmer, K., Pongam, P., Baker, C. 2018. Biological and genomic characterization of a novel Tobamovirus infecting Hoya spp.. Plant Disease. 102(12):2571-2577. https://doi.org/10.1094/PDIS-04-18-0667-RE.
DOI: https://doi.org/10.1094/PDIS-04-18-0667-RE

Interpretive Summary: This is the first report of a novel tobamovirus, Hoya chlorotic spot virus (HoCSV), infecting the popular ornamental plant Hoya in Florida. A description of the symptoms caused and biological and genomic characterization of the virus, including host range and diagnostic methods, are described. This report provides a timely account of this new virus and its potential to cause economic losses in ornamental crops to growers, Extension personnel and state and Federal regulatory and research scientists.

Technical Abstract: Foliar symptoms suggestive of virus infection were recently observed on the ornamental plant, Hoya (Hoya spp.; commonly known as waxflower), in Florida. An agent that reacted with commercially available tobamovirus detection reagents was mechanically transmitted to indicator plants, and virions were isolated from infected leaves. Rod-shaped particles ~300 nm in length and typical of tobamoviruses were observed in the partially purified preparations by electron microscopy. An experimental host range was determined by mechanical inoculation with virions. Systemic infections of tested plants in the Asclepiadaceae and Apocynaceae, and N. benthamiana in the Solanaceae were observed. A few other species in the Solanaceae and Chenopodiaceae were local hosts for this virus. No tested plants in the Amaranthaceae, Apiaceae, Brassicaeae, Cucurbitaceae, Fabaceae or Malvaceae were infected, including several common virus indicator hosts. The complete genome for the virus was determined and shown to have a typical tobamovirus organization. Comparisons of genome nucleotide sequence and individual open reading frame deduced amino acid sequences, indicate that it is a novel tobamovirus sharing the highest level of sequence identity with Streptocarpus flower break virus and members of the Brassicaceae-infecting subgroup of tobamoviruses. The virus, for which the name Hoya chlorotic spot virus (HoCSV) is proposed, was detected in multiple Hoya plants from different locations in Florida.