Pathogenesis of Alfalfa mosaic virus in Soybean (Glycine max) and Expression of Chimeric Rabies Peptide in Virus-Infected Soybean Plants

Rabies vaccine development by expression of recombinant viral glycoprotein

The rabies virus envelope glycoprotein (RVGP) is the main antigen of rabies virus and is the only viral component present in all new rabies vaccines being proposed. Many approaches have been taken since DNA recombinant technology became available to express an immunogenic recombinant rabies virus glycoprotein (rRVGP). These attempts are reviewed here, and the relevant results are discussed with respect to the general characteristics of the rRVGP, the expression system used, the expression levels achieved, the similarity of the rRVGP to the native glycoprotein, and the immunogenicity of the vaccine preparation. The most recent studies of rabies vaccine development have concentrated on in vivo expression of rRVGP by viral vector transduction, serving as the biotechnological basis for a new generation of rabies vaccines.

Seasonal Progression, Symptom Development, and Yield Effects of Alfalfa mosaic virus Epidemics on Soybean in Wisconsin

The occurrence of Alfalfa mosaic virus (AMV) has increased in Wisconsin soybean fields in conjunction with the establishment of the soybean aphid (Aphis glycines). Field studies were conducted to determine the seasonal incidence of AMV-infected plants, progression of symptom severity caused by AMV, and the effect of AMV on soybean yield and seed quality. An isolate of AMV, collected from field-grown soybean, was introduced into plots by mechanical inoculation of plants at the V1 growth stage. The goal of the experiment was to achieve an incidence of AMV-infected plants of 0, 50, and 100% in 2002, and 0, 10, 25, 50, 75, and 100% in 2003. Severity of foliar symptoms was rated, and leaf samples were collected for serological assay (enzyme-linked immunosorbent assay [ELISA]) to estimate the incidence of AMV-infected plants from growth stages VC to R5. The maximum incidence of AMV-infected plants was 49% at growth stage R5, yet detection of the virus by ELISA dropped dramatically thereafter in both years. Incidence of AMV-infected plants accounted for 53 to 67% of the variability observed for severity of foliar symptoms in 2002 and 2003, respectively. Maximum yield loss ranged from 32% in 2002 to 48% in 2003 based on the difference in yield between noninoculated plots and plots with the highest incidence of AMV-infected plants. Incidence of AMV-infected plants explained 31% of the variation in yield in 2002 and 26% in 2003. An AMV incidence of 30% or greater was required for yield loss caused by AMV. Results of this study suggest that AMV has the potential to lower soybean yield and warrants further study.