Molecular characterization, ecology, and epidemiology of a novel Tymovirus in Asclepias viridis from Oklahoma.
Native virus-plant interactions require more understanding and their study will provide a basis from which to identify potential sources of emerging destructive viruses in crops. A novel tymovirus sequence was detected in Asclepias viridis (green milkweed), a perennial growing in a natural setting in the Tallgrass Prairie Preserve (TGPP) of Oklahoma. It was abundant within and frequent among A. viridis plants and, to varying extents, within other dicotyledonous and one grass (Panicum virgatum) species obtained from the TGPP. Extracts from A. viridis containing the sequence were infectious to a limited number of species. The virus genome was cloned and determined to be closely related to Kennedya yellow mosaic virus. The persistence of the virus within the Oklahoma A. viridis population was monitored for five successive years. Virus was present in a high percentage of plants within representative areas of the TGPP in all years and was spreading to additional plants. Virus was present in regions adjacent to the TGPP but not in plants sampled from central and south-central Oklahoma. Virus was present in the underground caudex of the plant during the winter, suggesting overwintering in this tissue. The RNA sequence encoding the virus coat protein varied considerably between individual plants (≈3%), likely due to drift rather than selection. An infectious clone was constructed and the virus was named Asclepias asymptomatic virus (AsAV) due to the absence of obvious symptoms on A. viridis.
Plant Biology Division, Samuel Roberts Nobel Foundation, Inc., Ardmore, OK 73401, USA.
Byoung-Eun
BE
Min
Tracy S
TS
Feldman
Akhtar
A
Ali
Graham
G
Wiley
Vijay
V
Muthukumar
Bruce A
BA
Roe
Marilyn
M
Roossinck
Ulrich
U
Melcher
Michael W
MW
Palmer
Richard S
RS
Nelson
D031108:Asclepias / Q000821:virology*; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D040961:Genetic Drift; D014644:Genetic Variation; D016679:Genome, Viral / Q000235:genetics*; D005843:Geography; D058507:Host Specificity; D054884:Host-Pathogen Interactions; D008969:Molecular Sequence Data; D009825:Oklahoma; D010802:Phylogeny; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000821:virology; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D014026:Nicotiana / Q000821:virology; D017806:Tymovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
D036022:Capsid Proteins; D018076:DNA, Complementary; D012367:RNA, Viral