The production of biodegradable polymers as coproducts of other commercially relevant
plant components can be a sustainable strategy to decrease the carbon footprint and
increase the commercial value of a plant. The biodegradable polymer cyanophycin
granular polypeptide (CGP) was expressed in the leaves of a commercial tobacco
variety, whose seeds can serve as a source for biofuel and feed. In T0 generation in
the greenhouse, up to 11% of the leaf dry weight corresponded to the CGP. In T1
generation, the maximum content decreased to approximately 4% dw, both in the
greenhouse and first field trial. In the field, a maximum harvest of 4 g CGP/plant could
be obtained. Independent of the CGP content, most transgenic plants exhibited a slight
yield penalty in the leaf biomass, especially under stress conditions in greenhouse and field
trials. After the harvest, the leaves were either Sun dried or ensiled. The resulting material
was used to evaluate the extraction of CGP compared to that in the laboratory protocol.
The farm-level analysis indicates that the extraction of CGP from tobacco plants can
provide alternative income opportunities for tobacco farmers. The CGP yield/ha indicates
that the CGP production in plants can be economically feasible depending on the
cultivation and extraction costs. Moreover, we analyzed the consumer acceptance of
potential applications associated with GM tobacco in four European countries (Germany,
Finland, Italy and the Netherlands) and found unexpectedly high acceptance.