Gemini virus vectors for gene expression in plants

Abstract

A gene amplification system based on plant viral genetic elements dramatically increases foreign protein production in plants. A safer and more economical production system for vaccines and antibodies in recombinant plants grown using agricultural practice is described. The high-level expression system uses the replicative process of a plant mastrevirus, exemplified by bean yellow dwarf virus (BeYDV). The expression system is preferably inducible to avoid interference with plant growth and development. Developmental cues, such as fruit ripening, are employed to trigger expression of the foreign protein using a tissue-specific promoter. A single, stably integrated expression cassette for foreign protein is replicated extrachromosomally in ripening fruit, forming hundreds of transcriptionally competent copies. Preferred plant hosts include tomato as a model system and soybean for production of large quantities of protein at high total protein levels.