ARS | Publication request: Characterization of the Triticum Mosaic Virus Genome and Interactions between Triticum Mosaic Virus and Wheat Streak Mosaic Virus

Submitted to: Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: February 2, 2010
Publication Date: March 8, 2011
Citation: Tatineni, S., French, R.C. 2011. Characterization of the Triticum Mosaic Virus Genome and Interactions between Triticum Mosaic Virus and Wheat Streak Mosaic Virus. Workshop Proceedings. Abstract presented at Hard Winter Wheat Workers Workshop, University of Nebraska, Lincoln, NE March 7-9, 2010.

Technical Abstract: The complete genome sequence of Triticum mosaic virus (TriMV) has been determined to be 10,266 nucleotides encoding a large polyprotein of 3,112 amino acids. The proteins of TriMV possess only 33-44% (with NIb protein) and 15-29% (with P1 protein) amino acid identity with the reported members of Potyviridae. These results suggest that TriMV should be classified in a new genus, and we propose the genus Poacevirus in the family Potyviridae with TriMV as the type member. TriMV and Wheat streak mosaic virus (WSMV), distinct potyvirid species, infect wheat naturally in the Great Plains and are transmitted by wheat curl mites. We examined the interaction between WSMV and TriMV in three wheat cultivars at two temperature regimens (19ºC and 20-26ºC). Double infections in wheat cultivars Arapahoe and Tomahawk at both temperature regimens induced disease synergism with severe leaf deformation, bleaching, and stunting with a 2.2 to 7.4-fold increase in accumulation of both viruses over single infections at 14 days post-inoculation (dpi). However, at 28 dpi, in double infections at 20-26ºC, TriMV concentration was increased by 1.4 to 1.8-fold in Arapahoe and Tomahawk, but WSMV concentration was decreased to 0.5-fold. WSMV and/or TriMV replicated poorly in Mace at 19ºC with no synergistic interaction, whereas both viruses accumulated at moderate levels at 20-26ºC and induced mild to moderate disease synergism in doubly infected Mace when compared to Arapahoe and Tomahawk. Co-infections in Mace at 20-26ºC caused increased TriMV accumulation at 14 dpi and 28 dpi by 2.6- and 1.4-fold, and WSMV accumulated at 0.5- and 1.6-fold over single infections, respectively. Our data suggest that WSMV and TriMV induced cultivar-specific disease synergism in Arapahoe, Tomahawk, and Mace, and these findings could have several implications on management of wheat viruses in the Great Plains.