Viral Vector Expression of Foreign Proteins in Plants

Abstract

It is now fairly routine to engage plant viruses to express foreign proteins in plants. Plant viruses have several features that make them quite useful for vectoring foreign genes into whole plants. The majority of viruses infecting higher plants have single-stranded, positive-sense RNA genomes. Infectious transcripts can be synthesized in vitro from full-length cDNA clones to study RNA virus biology, develop methods of disease control and construct plant expression vectors (Goldbach and Hohn, 1997; Scholthof et al., 1996). Tobamoviruses are among the most studied and well-understood viruses and represent superbly efficient genetic systems (Dawson et al., 1986; Dawson et al., 1990; Dawson 1986). Vectors based on the tobacco mosaic virus (TMV) were among the first to be developed (Donson et al., 1991) and have several advantages for novel applications in the expression of foreign sequences in plants. These advantages include speed, high expression levels, broad host-range, and controlled containment, as transmission occurs only by mechanical means.