The goals 1-3 will generate information that will be of general importance for the efficient expression of foreign proteins in transgenic plants. The goal 4 will generate virus expression vectors that will be generally useful in plant molecular plants. These vectors will allow high level expression of foreign proteins in plants without the need to resort to time consuming transformation technology. The sobemovirus vectors will also have practical importance that will be tested in this project by the expression of vaccine proteins in infected plants. This work reflects a novel approach to the production of oral vaccines for use ultimately in both animals and humans. The final goals 5 and 6 will lead to the production of virus resistant plants and are a potential solution to the disease problems posed by the two viruses used in this project. The recent development of transformation technology in monocotyledonous plants means that the transgenic resistance is now a feasible target of plant biotechnology. The analysis of natural resistance will have a longer term benefit in the production of plants resistant to sobemoviruses and other pathogens.
The proposed work is a molecular analysis of cocksfoot mottle virus and rice yellow mottle virus. These are both members of the sobemovirus group and are pathogens of fodder crops and rice respectively. The programme has several related goals. These include:
1. The characterization of structure and functions of various sobemovirus proteins;
2. The understanding of translational strategies exploited by sobemoviruses;
3. The identification of promoters for the subgenomic RNA synthesis and translational enhancers and the evaluation of their potential as tools for the construction of efficient plant expression vectors;
4 Construction of transient plant expression vectors based on sobemoviral sequences and their use of the expression of foreign sequences, including vaccine antigens;
5. Analysis of natural resistance against different sobemoviruses and the identification of corresponding resistance genes;
6. Construction of transgenic plants expressing sobemovirus-derived sequences and the use of these plants for the studies on sobemovirus proteins functions and as the source for the genetically engineered resistance against sobemovirus infections.
Funding SchemeCSC - Cost-sharing contracts