|Choi, I - UNIVERSITY OF NEBRASKA|
|Morris, T - UNIVERSITY OF NEBRASKA|
Submitted to: American Phytopathological Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2000
Publication Date: June 1, 2000
Citation: French, R.C., Choi, I.R., Stenger, D.C., Morris, T.J. 2000. An rna viral gene expression vector for cereal crops. American Phytopathological Society Abstracts.Phytopathology 90:(Supplement)S25. Technical Abstract: An infectious clone of wheat streak mosaic virus (WSMV) was developed for transient expression of foreign gene sequences. NPT II and GUS genes were placed between the NIb and CP domains of the WSMV polyprotein. The NIb/CP protease cleavage site was duplicated, permitting excision of foreign proteins. NPT II was expressed in systemically infected wheat, barley, oat, ,and maize. The NPT II insert was stablely retained in the WSMV genome for at least 18 days p.i. and had little effect on viral CP accumulation. Histochemical assays detected GUS in systemically infected wheat and barley inoculated with WSMV-GUS. The GUS insert, which is about twice the size of the NPT II gene, was subject to deletion and CP accumulation was reduced relative to wild type, especially when GUS was produced as a fusion protein. GUS activity in oat was restricted to clusters of cells at infection foci 3 days p.i., whereas in maize GUS activity was not observed. .These results demonstrate utility of WSMV as a gene vector for systemic expression in cereals, and further indicate that both host and inserted sequences affect stability and expression of foreign genes.