The market for biologically-derived proteins is said to reach US$300 billion in the future. Currently, industrial enzymes and other proteins are made in large, expensive fermenting reactors, but using plants to produce them could reduce production costs by three times.

Researchers at Cornell University and the University of Illinois have engineered plants which can produce proteins not native to the plant itself. The research team genetically modified tobacco plants to produce the cellulase protein Cel6A, an enzyme. Tobacco is a heavily studied model plant because so much is known about it. Cel6A belongs to a large group of related enzymes used in many applications, including modern laundry detergents, fabric softener, and in food and animal feed. 

Genetic engineering was used to deliver DNA with instructions for making the desired protein into the chloroplasts of plants cells. The plants that adopted this DNA were then cultivated. Chloroplasts are the photosynthesizing organelles in plants and contain their own DNA. Plant cells cannot make their own chloroplasts but inherit them from each daughter cell during cell division.

"One of the advantages of the technology that we're using is that the chloroplasts in most crop plants are inherited through the maternal line, so the genes are not in the pollen," said Beth Ahner, professor of biological and environmental engineering at Cornell University.

For details, read the article in the Cornell Chronicle.