Global Indigo

Scientists and companies are developing and testing a large number of crops producing pharmaceuticals, biologics, and industrial and research chemicals. (Biologics are diagnostic or therapeutic products derived from living sources and are typically complex mixtures not easily identified or characterized.) A few of the products are discussed below. Names of many more crop-produced chemicals which are under development are not available to the public because under federal laws companies may withhold this information as confidential business data. Except where noted, the products described have not been commercialized.

• Pharmaceuticals or drugs
  Pharmaceuticals (or drugs), which are, generally speaking, chemicals intended to diagnose, treat, or prevent diseases, are being produced in a number of pharm plants. Among them are alpha-galactosidase and glucocerebrosidase, enzymes to treat Fabry’s and Gaucher’s diseases, respectively.

  Other proteins called “defensins” are being manufactured in plants with hopes that their antimicrobial characteristics will make them useful replacements for antibiotics. Drugs are also being produced as anticoagulants, blood substitutes, and hormones, and for wound repair and the treatment of anemia, liver cirrhosis, cystic fibrosis, HIV, and hepatitis B and C.

• Biologics
  Biologics are complex biological products such as antibodies, vaccines, and blood products used in human and veterinary medicine. In the biologics category, pharm plants are producing antibodies against the bacterium that causes tooth decay and for treatment of non-Hodgkin’s lymphoma. Vaccines against hepatitis B, rabies, HIV, malaria, autoimmune diabetes, and cholera are being produced in tobacco, corn, or potato plants. These vaccines will be purified from the plants before being given to humans, most likely by injection or as a pill. Crop-derived vaccines meant to be presented as food (edible vaccines) have been produced against diseases including, among others, measles, polio, diphtheria, yellow fever, and various types of viral diarrhea. These vaccines are being made in tomato fruit and other plant parts that can be eaten raw. (Cooking typically destroys the efficacy of vaccines.) Plant-produced edible vaccines are also being manufactured for veterinary purposes. Scientists recently conducted clinical trials in which pigs were fed a vaccine produced in corn against transmissible gastroenteritis virus (TGEV), one of the most important diseases in swine. And a vaccine meant to promote resistance to mink enteritis virus, canine parvovirus, and feline panleukopenia virus has been made in blackeyed beans.

  Industrial chemicals
  Industrial chemicals are compounds used in the manufacture of products like paper, plastics, personal care items, and laundry detergents. Many industrial chemicals are enzymatic proteins that promote the chemical reactions necessary for a particular manufacturing process. Trypsin, an enzyme traditionally isolated from bovine sources and used in large volumes in the detergent and leather industries, for example, and laccase, another enzyme used in making detergents but also in the manufacturing of fiberboard, are being produced in transgenic corn.

  Other useful industrial chemicals are the products of chemical reactions driven by enzymes, rather than enzymes themselves. Introducing particular enzymes into industrial crops can result in production of these types of industrial chemicals. For example, the first commercialized industrial crop incorporated a gene from the California bay tree to change the fatty acid biosynthesis pathways in canola. The added gene dramatically altered canola oil composition such that nearly 40% of the oil was comprised of lauric acid, a key raw material in the manufacture of soap, detergents, and cosmetic products. Conventional canola does not contain lauric acid.

• Research chemicals
  Chemical compounds used in research and diagnostic laboratories are referred to as research chemicals. The protein avidin, utilized for purifying other proteins, was the first research chemical commercialized from an industrial crop-in 1997. Beta-glucuronidase, another enzyme used extensively for plant molecular biology research was also commercialized in 1997.

  Multi-purpose chemicals
  The same plant-produced chemical may be used for different purposes. For example, the enzyme trypsin, discussed above as an industrial chemical, also has medical and research uses. Thus, corn plants engineered to synthesize trypsin are producing pharmaceuticals as well as industrial and research chemicals.