System for expression of genes in plants from a virus-based expression vector
TMV-based expression vector system modifications result in an easier, more reliable, and more cost-effective way to produce recombinant proteins in plants.
Plants exhibit potential as recombinant protein production systems. One method of inducing protein production involves a modified cDNA copy of an RNA plant virus. cDNAs are then transcribed in vitro, and RNA inoculated onto plants. This final step is expensive with variable success rates. Another strategy is agroinfection where a viral cDNA is joined to a plant promoter, cloned into an agrobacterium, and used to bring the viral cDNA into the plant genome. DNA is transcribed in the plant nucleus and the resulting RNA initiates replication in the plant cell. For certain cDNAs, this process is very inefficient. It has been shown to improve through a laborious process involving mutating cryptic introns into the candidate cDNA. Improving agroinfection efficiency of viral cDNA without intron alteration represents the next step in improving the efficiency of recombinant protein production systems.
The Ohio State University researchers, led by Dr. John Lindbo, determined that it is possible to improve the agroinfection efficiency of a viral cDNA clone without going through the laborious process of removing cryptic introns from a virus or inserting artificial introns into a virus. They have co-introduced an expressible gene for an RNA silencing suppressor along with the plant-functional promoter resulting in considerable agroinfection efficiency. This approach promises to improve agroinfection efficiencies of multiple plant species.