The biosafety of molecular farming in plants

Molecular farming in plants provides an inexpensive and convenient way to produce biopharmaceutical molecules and other valuable proteins on a large scale. Proof of principle has been demonstrated for a large number of recombinant human proteins, subunit vaccines and antibodies (Schillberg et al., 2002a, b), and detailed cost evaluations have been described for the production of technical proteins in corn (Kusnadi et al., 1997; Evangelista et al., 1998). In terms of biosafety, plants have several advantages over traditional production systems, such as the absence of endotoxins, human pathogens and oncogenic DNA sequences. However, other biosafety concerns remain to be addressed. These not only reflect the quality and safety of the final product, but also the wider effects of molecular farming on health and the environment. In this review we discuss the technological basis of molecular farming in plants and identify potential biosafety risks: transgene spread in the environment, recombinant protein accumulation in the ecosystem, contamination of food and feed chains with transgenes and their products, and product quality and safety.