Icon Genetics announces the publication in Nature Biotechnology (S. Marillonnet et al., Nature Biotechnol., DOI 10.1038/nbt1094, June, 2005) of the second of a series of research papers describing a new generation expression technology for plants developed by Icon Genetics researchers.

Today, plant biotechnology relies on two processes for delivery and expression of heterologous genes in plants: stable genetic transformation and transient infection with viral vectors. Although much faster, the transient route was until recently limited by viruses' low infectivity, and their inability to carry average-size or larger transgenes. A recently developed new generation transfection technology overcomes these limitations by relying on Agrobacterium as an infective systemic agent for delivery of viral replicons. This improved process is used to start gene amplification in all mature leaves of a plant simultaneously, leading to high expression levels. Such a transfection is indefinitely scalable and can be done on an industrial scale. This eclectic technology, called 'magnifection', combines advantages of three biological systems: (1) vector efficiency and efficient systemic DNA delivery of Agrobacterium, (2) speed and expression level/yield of a plant RNA virus, and (3) posttranslational capabilities and low production costs of plants. The proposed process allows for an industrial production platform that does not require genetic modification of plants, that is much faster than previous methods, and that is biologically safe.

The paper describes recently developed highly active synthetic templates for delivery of RNA viral vectors as DNA precursors. It also shows that Agrobacterium-mediated delivery of such templates can be used to start gene amplification in all mature leaves of a plant simultaneously (systemic transfection), and that this process can be performed on an industrial scale with different plant species.