“Discuss the contribution that biotechnology has made to agriculture, taking into account both the advantages and disadvantages of the technology”
“ Responsible biotechnology is not the enemy; starvation is. Without adequate food supplies at affordable prices, we cannot expect world health or peace.”
—Jimmy Carter,Former President of the United States, 11 Jul 1997
Using the techniques of modern biotechnology, one or twogenes(Smartstaxfrom Monsanto in collaboration with Dow AgroSciences will use 8, starting in 2010) may be transferred to a highly developed crop variety to impart a new character that would increase its yield.However, while increases in crop yield are the most obvious applications of modern biotechnology in agriculture, it is also the most difficult one. Current genetic engineering techniques work best for effects that are controlled by a single gene. Many of the genetic characteristics associated with yield (e.g., enhanced growth) are controlled by a large number of genes, each of which has a minimal effect on the overall yield.There is, therefore, much scientific work to be done in this area.
Reduced vulnerability of crops to environmental stresses
Crops containing genes that will enable them to withstand biotic and abiotic stresses may be developed. For example,droughtand excessively salty soil are two importantlimiting factorsin crop productivity. Biotechnologists are studying plants that can cope with these extreme conditions in the hope of finding the genes that enable them to do so and eventually transferring these genes to the more desirable crops. One of the latest developments is the identification of a plant gene,At-DBF2, fromArabidopsis thaliana, a tiny weed that is often used for plant research because it is very easy to grow and its genetic code is well mapped out. When this gene was inserted intotomatoandtobaccocells (seeRNA interference), the cells were able to withstand environmental stresses like salt, drought, cold and heat, far more than ordinary cells. If these preliminary results prove successful in larger trials, then At-DBF2 genes can help in engineering crops that can better withstand harsh environments.Researchers have also created transgenic rice plants that are resistant torice yellow mottle virus(RYMV). In Africa, this virus destroys majority of the rice crops and makes the surviving plants more susceptible to fungal infections.
Increased nutritional qualities
Proteins in foods may be modified to increase their nutritional qualities. Proteins in legumes and cereals may be transformed to provide the amino acids needed by human beings for a balanced diet.A good example is the work of ProfessorsIngo PotrykusandPeter Beyeron the so-calledGolden rice(discussed below).
Improved taste, texture or appearance of food
Modern biotechnology can be used to slow down the process of spoilage so that fruit can ripen longer on the plant and then be transported to the consumer with a still reasonable shelf life. This alters the taste, texture and appearance of the fruit. More importantly, it could expand the market for farmers in developing countries due to the reduction in spoilage. However, there is sometimes a lack of understanding by researchers in developed countries about the actual needs of prospective beneficiaries in developing countries. For example, engineering soybeans to resist spoilage makes them less suitable for producingtempehwhich is a significant source of protein that depends on fermentation. The use of modified soybeans results in a lumpy texture that is less palatable and less convenient when cooking.
The first genetically modified food product was a tomato which was transformed to delay its ripening.Researchers inIndonesia,Malaysia,Thailand,PhilippinesandVietnamare currently working on delayed-ripening papaya in collaboration with theUniversity of NottinghamandZeneca.
Biotechnology in cheese production:enzymes produced by micro-organisms provide an alternative to animal rennet - a cheese coagulant - and an alternative supply for cheese makers. This also eliminates possible public concerns with animal-derived material, although there are currently no plans to develop synthetic milk, thus making this argument less compelling. Enzymes offer an animal-friendly alternative to animal rennet. While providing comparable quality, they are theoretically also less expensive.
About 85 million tons of wheat flour is used every year to bake bread.By adding an enzyme called maltogenic amylase to the flour, bread stays fresher longer. Assuming that 10-15% of bread is thrown away as stale, if it could be made to stay fresh another 5-7 days then perhaps 2 million tons of flour per year would be saved. Other enzymes can cause bread to expand to make a lighter loaf, or alter the loaf in a range of ways.
Reduced dependence on fertilizers, pesticides and other agrochemicals
Most of the current commercial applications of modern biotechnology in agriculture are on reducing the dependence of farmers onagrochemicals. For example,Bacillus thuringiensis(Bt) is a soil bacterium that produces a protein with insecticidal qualities. Traditionally, a fermentation process has been used to produce an insecticidal spray from these bacteria. In this form, theBt toxinoccurs as an inactiveprotoxin, which requires digestion by an insect to be effective. There are several Bt toxins and each one is specific to certain target insects. Crop plants have now been engineered to contain and express the genes for Bt toxin, which they produce in its active form. When a susceptible insect ingests the transgenic crop cultivar expressing the Bt protein, it stops feeding and soon thereafter dies as a result of the Bt toxin binding to its gut wall. Bt corn is now commercially available in a number of countries to controlcorn borer(a lepidopteran insect), which is otherwise controlled by spraying (a more difficult process).
Crops have also been genetically engineered to acquire tolerance to broad-spectrumherbicide. The lack of herbicides with broad-spectrum activity and no crop injury was a consistent limitation in crop weed management. Multiple applications of numerous herbicides were routinely used to control a wide range of weed species detrimental to agronomic crops. Weed management tended to rely on preemergence—that is, herbicide applications were sprayed in response to expected weed infestations rather than in response to actual weeds present. Mechanical cultivation and hand weeding were often necessary to control weeds not controlled by herbicide applications. The introduction of herbicide-tolerant crops has the potential of reducing the number of herbicide active ingredients used forweed management, reducing the number of herbicide applications made during a season, and increasing yield due to improved weed management and less crop injury. Transgenic crops that express tolerance toglyphosate,glufosinateandbromoxynilhave been developed. These herbicides can now be sprayed on transgenic crops without inflicting damage on the crops while killing nearby weeds.
From 1996 to 2001, herbicide tolerance was the most dominant trait introduced to commercially available transgenic crops, followed by insect resistance. In 2001, herbicide tolerance deployed insoybean,cornandcottonaccounted for 77% of the 626,000 square kilometres planted to transgenic crops; Bt crops accounted for 15%; and "stacked genes" for herbicide tolerance and insect resistance used in both cotton and corn accounted for 8%.
Production of novel substances in crop plants
Biotechnology is being applied for novel uses other than food. For example,oilseedcan be modified to produce fatty acids fordetergents, substitutefuelsandpetrochemicals.Potatoes,tomatoes,ricerereretobacco,lettuce,safflowers, and other plants have been genetically-engineered to produceinsulinand certainvaccines. If future clinical trials prove successful, the advantages of ediblevaccineswould be enormous, especially for developing countries. The transgenic plants may be grown locally and cheaply. Homegrown vaccines would also avoid logistical and economic problems posed by having to transport traditional preparations over long distances and keeping them cold while in transit. And since they are edible, they will not need syringes, which are not only an additional expense in the traditional vaccine preparations but also a source of infections if contaminated.In the case of insulin grown in transgenic plants, it is well-established that the gastrointestinal system breaks the protein down therefore this could not currently be administered as an edible protein. However, it might be produced at significantly lower cost than insulin produced in costly, bioreactors. For example, Calgary, Canada-basedSemBioSys Genetics, Inc.reports that its safflower-produced insulin will reduce unit costs by over 25% or more and approximates a reduction in the capital costs associated with building a commercial-scale insulin manufacturing facility of over $100 million, compared to traditional biomanufacturing facilities.
Biotech products are moving on from simple modifications of plant cells to manipulation of mammalian and even human cells, encroaching further into areas of moral or psychological discomfort.
Then, there is the increasing speed with which information and misinformation about biotech products is traveling electronically around the globe in e-mails and blogs and chat rooms. This means opinions are likely to become entrenched more quickly, often on flimsier evidence, and industry will need a means of anticipating controversies and responding more rapidly.
And finally, the increasing internationalization of trade and technical capability will mean that new biotech products will be adopted by economies somewhere, even if the U.S. or Europe remains embroiled in an ethical/policy debate.
Industry's preference for working behind the scenes and in the lobby halls is all very well. But the values debate is also part of market reality. These issues need to be addressed in a moderating body similar to the Pew initiative. Waiting until they are raised by a congressional committee loaded with opponents, when public opinion is antagonistic and the media start to smell blood, will be too late. By then, the battle for hearts and minds will already have been lost.
Since the earliest days of agricultural biotechnology development, scientists have envisioned harnessing the power of genetic engineering to enhance nutritional and other properties of foods for consumer benefit. The first generation of agricultural biotechnology products to be commercialized, however, were more geared towards so-called input traits, genetic modifications that make insect, virus and weed control easier or more efficient. These first products have been rapidly adopted by U.S. farmers, and now account for the majority of soybeans, cotton and corn grown in the United States.
Agricultural biotechnology innovations aimed directly towards consumers, sometimes collectively referred to as output traits, have been a longer time in development. As the technology advances, and we learn more about the genes and biochemical pathways that control those attributes that could offer more direct consumer benefits, the long-awaited promise of genetically engineered food with more direct consumer benefits moves closer to reality.
One category of potential products aimed at consumers is those products with added health benefits, also known as “functional foods.” The term functional food means different things to different people, but generally refers to foods that provide health benefits beyond basic nutrition. This report looks at the potential to develop functional foods through the Application of modern biotechnology.
In 1990, the U.S.Food and Drug Administration (FDA) approved the first genetically engineered food ingredient for human consumption, the enzyme chymosin, used in cheesemaking. It is estimated that today 70% or more of cheese made in the U.S. uses genetically engineered chymosin. The first genetically engineered food, the FlavrSavr™ tomato, was approved for human consumption in the U.S. in 1994.
Seven million farmers in 18 countries now grow genetically engineered crops. Leading countries are the U.S., Argentina, Canada, Brazil, China, and South Africa. Cultivation of genetically engineered crops globally has expanded more than 10% per year for the past seven years, according to the International Service for the Acquisition of Agri-biotech Applications (ISAAA, James 2004). Such an expansion rate amounts to a 40-fold increase in the global area of transgenic crops from 1996 to 2003. Thus, in spite of continuing controversy, the technology continues to be adopted by farmers worldwide. ISAAA highlighted its key findings this way:
In 2003, GM crops were grown in 18 countries with a combined population of 3.4 billion, living on six continents in the North and the South: Asia, Africa and Latin America, and North America, Europe and Oceania…. the absolute growth in GM crop area between 2002 and 2003 was almost the same in developing countries (4.4 million hectares) and industrial countries (4.6 million hectares) … the three most populous countries in Asia—China, India, and Indonesia, the three major economies of Latin America—Argentina, Brazil and Mexico, and the largest economy in Africa, South Africa, are all officially growing genetically engineered crops.
The leading genetically engineered crops globally and in the U.S. are soy, maize (corn), cotton, and canola. In the U.S., transgenic virus-resistant papaya and squash are also cultivated.
Research in plant biotechnology has focused primarily on agronomic traits—characteristics that improve resistance to pests, reduce the need for pesticides, and increase the ability of the plant to survive adverse growing conditions such as drought, soil salinity, and cold. Biotechnology traits developed and commercialized to date have largely focused on pest control (primarily Bt crops) or herbicide resistance. Many plant pests have proven either difficult or uneconomical to control with chemical treatment, traditional breeding, or other agricultural technologies and in these instances in particular, biotechnology has proven to be an effective agronomic tool. Herbicide resistance allows farmers to control weeds with chemicals that would otherwise damage the crop itself.
Varieties combining two different traits, such as herbicide tolerance and insect resistance, have been introduced in cotton and corn. The addition of new traits, such as resistance to rootworm in maize, and the combinations of traits with similar functions, such as two genes for resistance to lepidopteran pests in maize, are expected to increase. In its 2003 report, ISAAA suggested that five new Bt and novel gene products for insect resistance in maize could be introduced. While the improvement of agronomic characteristics in major crops has been highly successful, few products genetically engineered to meet the specific needs of either food processors or consumers have yet been commercialized. Recently, however, a renewed emphasis on developing agricultural biotechnology applications more relevant to consumers has accompanied continuing efforts to develop crops with improved agronomic traits. Although genetically engineered crops with enhanced health, nutrition, functional, and consumer benefits have lagged behind agronomic applications, research on many such products is in the advanced stages of development. These applications could improve human and livestock nutrition and health, the nutritional quality of food animals for human consumption, and create ingredients with superior properties for food manufacturing and processing.