Preliminary evaluation of transgenic tomato plants expressing a Yersinia pestis antigen fusion protein F1-V Grown in a Greenhouse

Transgenic plants expressing high-value pharmaceutical protein have great potential for inexpensive and scalable protein production systems. Greenhouse tomato production is a suitable platform for such high-value protein production, achieving high biomass yield, increased containment and environmental control capacity. Our ultimate goal is to develop a greenhouse-based efficient protein production system. In this study, using transgenic tomato plants expressing a predominant antigen fusion protein F1-V against plague as a model system, we characterized growth and development of the transgenic plants under typical semiarid greenhouse conditions and evaluated fruit and protein productivity. Two transgenic lines, 'T22.11' and 'T3D1.2', carrying the transgene f1-v and two non-transgenic tomato cultivars, 'TA234' (wild type) and 'Durinta' (commercial cultivar as reference), were used as the plant material. All plants were grown hydroponically in a greenhouse equipped with a temperature control system from September 2007 to March 2008. Cumulative fruit yield per plant was significantly higher in 'Durinta' than in 'T22.11', 'T3D1.2' and 'TA234', while total soluble-protein (TSP) concentration of fruits of 'Durinta' was significantly lower than those of the other lines. As a result, estimated cumulative TSP production was the lowest in 'Durinta'. This suggests that a tomato cultivar having high biomass productivity is not necessarily suitable for high-value protein production.