CORDIS - EU research results

Mechanisms of transgene integration and expression in crop plant plastids: underpinning a technology for improving human health

Final Report Summary - PLASTOMICS (Mechanisms of transgene integration and expression in crop plant plastids: underpinning a technology for improving human health)

The aim of the project was a detailed understanding of the genes and proteins involved in several key stages of plastid transformation and foreign gene expression in different plastid types in tobacco, tomato and potato. This information should result in higher plastid transformation frequencies, regulated expression of transgenes in different plastid types and improved stability of plastid-located proteins.

The project has been successful in achieving most of the proposed objectives. It has developed an understanding of the proteins involved in transgene integration into and excision from the plastid genome, and has developed a novel automatic marker excision system. It has identified the most highly expressed genes in chromoplasts and amyloplasts, and the role of the two nuclear-encoded RNA polymerases in the transcription of different genes. It has developed control elements that increase the expression of foreign genes in tobacco chloroplasts. It has developed our understanding of plastid proteolysis components and produced a cleavable protein-fusion system that is able to produce large amounts of interferon 2b in tobacco chloroplasts.

The PLASTOMICS consortium has made a major contribution to our understanding of the processes underlying the insertion, and removal, of foreign genes into the plastid genome of tobacco, potato and tomato. The size and expertise of the consortium is greater than any other grouping throughout the world, and places the European Union in pole position for advances in plastid transformation in the future. Commercially important results have been obtained, and Icon Genetics GmbH has applied for a European patent (patent application 07012281.7) for a translation control element developed from their work. The translation control element is independent of existing patents that restrict the use of 5'-regulatory elements of plant chloroplast origin or from the phage T7 gene 10. It provides therefore an efficient and valuable alternative to these patented regulatory elements. Icon Genetics also obtained proof-of-concept for a novel method of marker gene excision that had been the subject of a previous European patent application.