By Dan Burden, specialist, AgMRC, Iowa State University, djburden@iastate.edu.
Profile reviewed July 2008.
Biotechnology-produced crops, pharmaceutical and other specialty protein production are a controversial area of value-added agricultural development. These crop production systems differ from the conventional artificial selection associated with plant breeding because modern biotechnological technology is utilized to transfer genes responsible for plant development and product production traits across natural biological or ecological barriers. Also, rather than a whole seed that is subdivided into many products, as is the case with traditional commodity agriculture, an individual chemical compound in the fruit of the plant may be the target of the harvest and subsequent specialized processing. For this reason, these production systems usually incorporate "identity preservation" strategies. These are handing and management techniques that ensure product purity and quality integrity.
Modern biotechnology now allows farmers to "grow" compounds present throughout the animal and plant kingdoms using commonly employed traditional cropping systems. With modern biotechnology, genes from an organism evolutionarily far removed from a host plant may be incorporated into that plant to engineer a new variety with special adaptations that affect agronomic production, enhance a particular product characteristic or produce an entirely new protein product that can be expressed within or "harvested" from the host plant's fruit or seeds.
Additionally, genetic engineering uses the information in a given organism's genetic code. This information is incorporated in specialized proteins that code for the production of other proteins that are responsible for the expressed products or traits that one sees throughout the animal and plant kingdoms. Genes may be manipulated to contribute, for example, to skin color, seed size or drought tolerance. In other cases, they are regulatory in nature and the expression of wanted or unwanted characteristics can be moderated or triggered to the benefit of the organism.
Biotechnology crop production systems usually are referred to as producing "transgenic" crops, meaning "gene-transferred" crops. Two common examples are referred to as "Roundup-Ready soybeans" and "Bt-corn." To understand the conceptual basis for these crop systems, let's examine the thinking behind Bt-corn.
Bt-corn are several varieties of corn plants that incorporate a genetic system from the Bacillus thuringiensis bacterium that encodes for a protein crystal that is highly toxic to leaf-feeding insect and aquatic mosquito larvae. This bacteria has been used for decades by organic gardeners and pest control practitioners. The concept behind Bt-corn was to incorporate a powerful natural insecticide with no mammalian toxicity from a bacterium into a plant to confer very selective insecticidal activity to only those insects that feed upon the plant, thereby avoiding any detrimental impact on non-target organisms, groundwater pollution and other environmental impacts (all of which resulted from conventional pesticide use). A secondary benefit was to increase the yield of the corn variety through added vigor due to elimination of the detrimental effects of defoliation, root and stalk damage, and water loss that results from insect feeding. It also is argued that additional crop value and environmental benefit is obtained through less product-, machine- and fuel-related costs due to less chemical production and use, and decreased field treatments.
Transgenic crop systems have significantly evolved from the initial Roundup-Ready soybeans and Bt-corn. Mass-produced commodity crops with age old well-developed production technologies are now seen as highly cost-effective factories for the large-scale production of very high value specialty proteins. These proteins can be for human or animal food, medicinal, therapeutic or industrial applications. In some cases, transgenic crops offer an opportunity to produce important human and animal vaccines and nutritional supplements in a manner that can make them available to the developing world's human and animal masses. These pharmaceutical farming transgenic crop production systems are now commonly referred to in the popular press as "pharming" or "bio-pharming."
Critics of the technology play upon the image of crazed scientists, beyond the fringe of rational thinking, creating "Franken-crops" solely for scientific recognition or the profit of huge multi-national corporations. Because of these concerns, industry guidelines have been developed. It is now widely recognized that the concept of genetic pollution is a valid concern. This concern has driven much of the regulatory thinking that ascertains which particular transgenic production technologies are appropriate and which are potentially hazardous to humans, the human food supply or the non-human environment.
Currently, transgenic technologies continue to develop, although, with very few exceptions, they are not being grown outside of contained systems. Currently, no drugs produced in genetically engineered plants are on the market. The Union of Concerned Scientists recently summarized the types of substances being engineered into pharmaceutical and industrial crops (http://www.ucsusa.org/food_and_environment/biotechnology/page.cfm?pageID=1373) and from Innvista.com (http://www.innvista.com/health/foods/geneteng/othercr.htm). The following paragraphs are derived from their websites and are a list of experimental pharmaceutical and industrial substances that have been engineered into crop plants.
With respect to pharmaceuticals, proteins for healing wounds and treating conditions such as anemia, liver cirrhosis and cystic fibrosis; anticoagulants; blood substitutes; hormones; and enzymes to treat Fabry's and Gaucher's diseases are in development. Specialty antibodies, the substances that hone in on disease-causing molecules with great specificity (examples include antibodies to fight cancer and tooth decay), have been isolated and incorporated into plant production systems.
Vaccines, substances that can be injected or given orally to humans and animals to confer immunity to diseases, are another focus of intense investigation. These include vaccines that protect against non-Hodgkin's lymphoma, rabies, cholera, piglet diarrhea and foot-and-mouth disease. So-called "edible" vaccines are fruits and vegetables engineered to contain vaccines that are delivered by oral ingestion rather than hypodermic injection. Edible vaccines originally were envisioned to be dispensed within whole foods like tomatoes that could be eaten raw, but dosing and quality control considerations have led most developers to consider at least minimal processing of these foods. Edible vaccines are being developed against hepatitis B, measles, polio and various types of viral diarrhea. A study by the National Corn Growers Association (http://www.ncga.com/biotechnology/main/) found that some 400 plant-based drugs are being developed worldwide.
Industrial chemicals include those compounds used in the manufacture of products such as paper, plastics, personal care items and laundry detergents. Notable examples include trypsin and laccase, as well as avidin and beta-glucuronidase, research chemicals that are used in investigative and diagnostic laboratories.
Other transgenic research includes a number of novel plant systems. Researchers at the Boyce Thompson Institute for plant research at Cornell University are modifying bananas to produce a hepatitis B vaccine. Scientists at Purdue University, along with the USDA, are developing GE tomatoes that will ripen later and give them a longer shelf life. The tomatoes also contain higher levels of lycopene, a substance that may lower the risk of prostate cancer.
Marine vegetation is being investigated by Chinese scientists who have isolated a gene that would allow certain crop plants to thrive in saltwater. Scientists in India have added a nutritional improvement gene to potato that is supposed to produce more protein and essential amino acids. Rice in the form of "golden rice” is being genetically engineered to produce the beta-carotene needed to increase vitamin A levels in the body. The goal of this work is to help the millions of people in the developing world that suffer blindness each year due to vitamin A deficiency. Currently, golden rice is undergoing safety and nutrition testing. In Africa, scientists are working on an engineered sweet potato that will resist a virus responsible for consuming more than three-quarters of the harvest in central Africa.
The International Service for the Acquisition of Agri-Biotech Applications, Cornell University (http://www.isaaa.org/) reported 2007 was the 12th anniversary of the commercialization of genetically modified (GM) or transgenic crops, now often called biotech crops. Plantings in 2007 grew by 12 percent or 12.3 million hectares (30 million acres) to reach 114.3 million hectares (282.4 million acres).
The 23 countries growing biotech crops in 2007, including 12 developing countries and 11 industrial countries were, in order of hectarage: United States, Argentina, Brazil, Canada, India, China, Paraguay, South Africa, Uruguay, the Philippines, Australia, Spain, Mexico, Columbia, Chile, France, Honduras, Czech Republic, Portugal, Germany, Slovakia, Romania and Poland. More than 90 percent of the farmers using biotech crops in 2007 were resource-poor farmers from developing countries. The continuing rapid adoption of biotech crops reflects the substantial improvements in productivity, the environment, economics, health and social benefits realized by both large and small farmers, consumers and society in both industrial and developing countries.
More than one-third or 43 percent of the global biotech crop area, equivalent to 49.4 million hectares, was grown in developing countries where growth continued to be strong. It is noteworthy that the absolute growth in biotech crop area between 2006 and 2007 was higher for developing countries at 21 percent growth (8.5 million hectares) compared to 6 percent in the industrial countries (3.8 million hectares).
The Americans and GM Food: Knowledge, Opinion & Interest in 2004 by the Food Policy Institute at Rudgers University summarized America's perceptions of biotech agriculture. In this report, the results of a longitudinal study of Americans’ knowledge and feelings about agricultural biotechnology and how those perceptions and attitudes have changed over time were summarized. Three independent national probability samples of 1,200 adults were interviewed by phone in 2001, 2003 and 2004. Copies of this report are available at http://www.foodpolicyinstitute.org.
The report begins with an investigation of Americans’ awareness of the presence of genetically modified (GM) ingredients in the foods they encounter everyday. Next, the report describes Americans’ actual and perceived knowledge of science, biotechnology and food production. It then examined American opinions about GM foods in general, along with their opinions on a variety of existing and potential GM food products with direct or indirect consumer benefits. The report discusses the relationship between opinions of GM food and a variety of factors, including demographics, knowledge of biotechnology, purchasing behaviors and styles of food selection. Finally, it describes Americans’ thoughts on GM food labeling.
In summary, Americans pay little attention to agricultural biotechnology. Only half of Americans are aware that foods containing GM ingredients were sold in stores. Despite the prevalence of such foods, only one-quarter of Americans believe they have eaten them. Little more than 42 percent of Americans have ever discussed biotechnology.
The report continued that Americans have little knowledge of agricultural biotechnology. Self-reported knowledge of what biotechnology was and how it impacted their lives was low to nonexistent. Quizzes on biotechnology and food production reveal that Americans were generally uninformed about both. Opinion on the acceptability of GM foods was split. When directly questioned, about 27 percent of Americans reported that they approved of plant-based GM foods. Another 38 percent were unsure and 11 percent neither approved nor disapproved plant-based GM foods. Sixteen percent approved of animal-based GM foods while 33 percent were unsure and 8 percent neither approved nor disapproved animal-based GM foods.
Americans’ stance on labeling of GM food is unclear. It also was found that reaction to the technology depended upon what it was called and how it was labeled. The term biotechnology evoked the most positive responses, while genetic modification was most negatively perceived. The term genetic engineering was most often associated with cloning. With respect to labeling issues when directly questioned, 89 percent of Americans agreed that GM ingredients should be labeled as such.