Of more immediate practical use to the GARNet community than the technology described here are toolkits presented at the 4th New Phytologist Workshop by Susan Rosser (University of Glasgow) and Keith Saunders (John Innes Centre).
Susan Rosser presented a soon-to-be-published multi-gene assembly kit based on synthetic integrons – ‘Syntegron’. Like existing kits for manipulating DNA, it involves cassettes which top and tail each gene or section of DNA. Unlike other kits, it will be open source and allows for many genes, even a whole pathway, to be assembled, shuffled if required, and expressed. It has been demonstrated to work on the 5-gene violacein pathway which was put, complete and functioning, into E. coli in just 5 days. I’m pretty sure this protocol will be a hit, and it will be an excellent method for a group to use when they try out synthetic biology for the first time.
Keith Saunders presented another gene transfer method, the CPMV-HT expression system which won the BBSRC Innovator of the Year award for Professor George Lomonossoff and Dr Frank Sainsbury. Their system is based on empty virus-like particles (eVLPs), made from modified cow pea mosaic virus (CPMV). Simply, the vector is a body made of CPMV coat proteins, encapsulating the gene the user wishes to insert into a plant and the cis-acting sequences from the original viral RNA, which enhance translation of the gene of interest. The CPMV-HT system allows foreign proteins to be produced in plants at higher levels than before, and in a much shorter timescale too. It makes the idea of plants as bioreactors much more likely than previously. In a recently published experiment, the CPMV-HT expression system was used to express up to 0.5 mg recombinant human gastric lipase per gram of infiltrated leaf tissue in Nicotiana benthamiana.
The Syntegron tool kit will be published soon – GARNet will be sure to inform you when it is. The CPMV-HT vectors are available to academic researchers. If you want to try them, contact the Lomonossoff group: george.lomonossoff@jic.ac.uk.