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ARS Home » Plains Area » Lincoln, Nebraska » Wheat, Sorghum and Forage Research » Research » Publications at this Location » Publication #320488
Title: Triticum mosaic virus exhibits limited population variation yet shows evidence of parallel evolution after replicated serial passage in wheat

Author
item Bartels, Melissa
item French, Roy
item Graybosch, Robert
item Tatineni, Satyanarayana - Ts

Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2016
Publication Date: 2/22/2016
Citation: Bartels, M.S., French, R.C., Graybosch, R.A., Tatineni, S. 2016. Triticum mosaic virus exhibits limited population variation yet shows evidence of parallel evolution after replicated serial passage in wheat. Virology. 492:92-100.

Interpretive Summary: Triticum mosaic virus (TriMV) is a recently discoverd virus infecting wheat in the Great Plains of North America. Information on the genetic stability evolution of new strains is required for forecasting severity of outbreaks and development of effective management strategies for TriMV. The rate of TriMV evolution was evaluated by repeated and serial infections of greenhouse-grown wheat plants. The mutation frequencies in serially passaged TriMV was significantly low compared to other plant viruses, suggesting that genetic drift and bottlenecking events are impacting the population. The observed low mutation frequency and mutation rate/replication of TriMV in serial passages suggest that transgenic approaches for viral control might be useful to control TriMV. Furthermore, data obtained in this investigation suggest that TriMV may take a long time to overcome resistant wheat cultivars compared to that of Wheat streak mosaic virus, another wheat infecting virus.

Technical Abstract: An infectious cDNA clone of Triticum mosaic virus (TriMV) (genus Poacevirus; family Potyviridae) was used to establish three independent lineages in wheat to examine intra-host population diversity levels within protein 1 (P1) and coat protein (CP) cistrons over time. Genetic variation was assessed at passages 9, 18 and 24 by single-strand conformation polymorphism, followed by nucleotide sequencing. The founding P1 region genotype was retained at high frequencies in most lineage/passage populations, while the founding CP genotype disappeared after passage 18 in two lineages. We found that rare TriMV genotypes were present only transiently and lineages followed independent evolutionary trajectories, suggesting that genetic drift dominates TriMV evolution. These results further suggest that experimental populations of TriMV exhibit lower mutant frequencies than that of Wheat streak mosaic virus (genus Tritimovirus; family Potyviridae) in wheat. Nevertheless, there was evidence for parallel evolution at a synonymous site in the TriMV CP cistron.