Economic perspectives of molecular farming in greenhouse horticulture

Greenhouse growers increasingly consider conversion, because of fluctuating market prices and decreasing expected margins. Molecular farming (MF), using genetically modified (GM) plants as protein factories, is one of the eligible options to enhance profitability. Given current legislation and public opinion on GM plants, in particular in the EU, the containment production in greenhouses and its stable production conditions are seen as an opportunity for MF. This paper focuses on Arabidopsis thaliana as seed-specific production platform. To evaluate the factors which may be crucial for possible conversion of greenhouse companies and the possible impact of conversion at firm level, simulations are carried out based on individual data from greenhouse companies belonging to the Flemish Farm Accountancy Data Network (FADN). Estimations of protein yields are based on experiments with Arabidopsis thaliana. Conversion simulations are carried out for different types of greenhouse companies (ornamental plants, vegetables) and for different yield levels of proteins. The results show that the impact of conversion to MF in greenhouse horticulture is highly firm specific. For each greenhouse company in the sample, on the basis of an opportunity cost perspective, a threshold price for conversion is calculated, allowing to construct supply curves for both ornamental plant and vegetable growers. These findings reveal feasibility for certain greenhouse growers to produce high-value recombinant proteins in limited amounts, such as medication for rare diseases and clinical trials. Sensitivity analyses show that threshold prices are influenced by productivity fluctuations, indicating that greenhouse MF has potential to improve competitiveness through technological progress. This opens perspectives for further profitability increases, while learning by doing, and for more growers to step into the MF system innovation.