Agroinfiltration

The main benefit of agroinfiltration when compared to the more traditional plant transformation is speed and convenience, although yields of the recombinant protein are generally also higher and more consistent.

Subsequently, the strain is grown in a liquid culture and the resulting bacteria are washed and suspended into a suitable buffer solution.

Once inside the leaf the Agrobacterium remains in the intercellular space and transfers the gene of interest as part of the Ti plasmid-derived T-DNA in high copy numbers into the plant cells.

The gene is then transiently expressed through RNA synthesis from appropriate promoter sequences in all transfected cells (no selection for stable integration is performed).

Transient expression in cultured plant cell packs is a new procedure, recently patented by the Fraunhofer Institute IVV, Germany.

In order to defend itself against viruses and other pathogens that introduce foreign nucleic acids into their cells, plants have developed a system of post-transcriptional gene silencing (PTGS) where small interfering RNAs are produced from double-stranded RNA in order to create a sequence specific degradation pathway that efficiently silence non-native genes.

[6][7][8] Although it is not clear exactly how p19 works to suppress RNA silencing, studies have shown that transiently expressed proteins in Nicotiana benthamiana leaves have an up to 50-fold higher yield when coinfiltrated with TBSV p19.