Submitted to: Archives of Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/12/2007
Publication Date: 10/25/2007
Citation: Young, B.A., Hein, G.L., French, R.C., Stenger, D.C. 2007. Substitution of conserved cysteine residues in Wheat streak mosaic virus HC-Pro abolishes virus transmission by the wheat curl mite. Archives of Virology 152:2107-2111. Interpretive Summary: Mutations introduced into the HC-Pro coding region of Wheat streak mosaic virus (WSMV) were evaluated for systemic infectivity to wheat and vector transmission by the wheat curl mite. Ten WSMV mutants bearing point mutations in HC-Pro retained infectivity and wild-type pathogenicity when inoculated to wheat. Cysteine to alanine substitution at three positions within a conserved zinc-finger motif abolished transmission by the wheat curl mite. Mutation at other positions had no effect on vector transmission or resulted in reduced vector transmission efficiency. These results provide evidence that vector transmission of WSMV requires a functional zinc-finger in the amino-terminal region of HC-Pro.
Technical Abstract: Substitutions in the amino-terminal region of Wheat streak mosaic virus (WSMV) HC-Pro were evaluated for effects on transmission by the wheat curl mite (Aceria tosichella Keifer). Alanine substitution at cysteine residues 16, 46 and 49 abolished vector transmission. Although alanine substitution at Cys20 had no effect, substitution with arginine reduced vector transmission efficiency. Random substitutions at other positions (Lys7 to Asn, Asn19 to Ile, and Arg45 to Lys) did not affect vector transmission. These results suggest that a zinc finger-like motif (His13-X2-Cys16-X31-Cys46-X2-Cys49) in WSMV HC-Pro is essential for vector transmission.