Use of Biotechnology in Agriculture and its Benefits

Biotechnology is the application of scientific techniques to modify and improve plants, animal and microorganisms to enhance their value. Agricultural biotechnology is the area of f biotechnology involving application to agriculture. Agricultural biotechnology has been practiced for a long time, as people have sought to improve agriculturally important organisms by selection and breeding. An example of traditional agricultural biotechnology is the development of disease-resistant wheat varieties by cross-breeding different wheat types until the desired disease resistance was present in a resulting new variety.

In the 1970s, advances in the field of molecular biology provided scientists with the ability to manipulate DNA—the chemical building blocks that specify the characteristicsof living organisms at the molecular level. This technology is called genetic engineering. It also allows transfer of DNA between more distantly related organisms than was possible with traditional breeding techniques.  Today, this technology has reached a stage where scientists can take one or more specific genes from nearly any organism, including plants, animals, bacteria, or viruses, and introduce those genes into another organism. An organism that has been transformed using genetic engineering techniques is referred to as a transgenic organism, or a genetically engineered organism.

 Many other terms are in popular use to describe these aspects of today’s biotechnology. The term “genetically modified organism” or “GMO” is widely used, although genetic modification has been around for hundreds if not thousands of years, since deliberate crosses of one variety or breed with another result in offspring that are genetically modified compared to the parents. Similarly, foods derived from transgenic plants have been called “GMO foods,” “GMPs” (genetically modified products), and “biotech foods.” While some refer to foods developed from genetic engineering technology as “biotechnology-enhanced foods,” others call them “frankenfoods.” For the reasons discussed later in this publication, controversy affects various issues related to the growing of genetically engineered organisms and their use as foods and feeds.

What is the difference between genetic modification and conventional breeding?

Traditionally, a plant breeder tries to exchange genes between two plants to produce offspring that have desired traits. This is done by transferring the male (pollen) of one plant to the female organ of another. This cross breeding, however, is limited to exchanges between the same or very closely related species. It can also take a long time to achieve desired results and frequently, characteristics of interest do not exist in any related species. GM technology enables plant breeders to bring together in one plant useful genes from a wide range of living sources, not just from within the crop species or from closely related plants. This powerful tool allows plant breeders to do faster what they have been doing for years – generate superior plant varieties – although it expands the possibilities beyond the limits imposed by conventional plant breeding.

Whatever technique is used, the genome of the new variety is different from the parents, but convention dictates that this is not considered to be genetic modification, the term being reserved for the products of r-DNA technology. GM technology aims to produce new varieties by adding (or modifying the expression of) specific genes known to control particular traits. GM is more targeted (only a few genes carrying known functions are inserted in the recipient genome) and more rapid (bypassing the multiple cross generations needed by traditional breeding). It also allows plants to be used to produce molecules which could not be obtained otherwise, such as vaccines or bio-plastics. Where conventional techniques are effective, they will be used, but genetic modification allows a wider range of useful traits to be incorporated into a given crop.

  What are the benefits of genetic engineering in agriculture?

Everything in life has its benefits and risks, and genetic engineering is no exception. Much has been said about potential risks of genetic engineering technology, but so far there is little evidence from scientific studies that these risks are real. Transgenic organisms can offer a range of benefits above and beyond those that emerged from innovations in traditional agricultural biotechnology. Following are a few examples of benefits resulting from applying currently available genetic engineering techniques to agricultural biotechnology.

Increased crop productivity:

Biotechnology has helped to increase crop productivity by introducing such qualities as disease resistance and increased drought tolerance to the crops. Now, researchers can select genes for disease resistance from other species and transfer them to important crops. For example, researchers from the University of Hawaii and Cornell University developed two varieties of papaya resistant to papaya ringspot virus by transferring one of the virus’ genes to papaya to create resistance in the plants. Seeds of the two varieties, named ‘SunUp’ and ‘Rainbow’, have been distributed under licensing agreements to papaya growers since 1998.

Further examples come from dry climates, where crops must use water as efficiently as possible. Genes from naturally drought-resistant plants can be used to increase drought tolerance in many crop varieties.

Crop protection:

Farmers use crop-protection technologies because they provide cost-effective solutions to pest problems which, if left uncontrolled, would severely lower yields. As mentioned above, crops such as corn, cotton, and potato have been successfully transformed through genetic engineering to make a protein that kills certain insects when they feed on the plants. The protein is from the soil bacterium Bacillus thuringiensis, which has been used for decades as the active ingredient of some “natural” insecticides.

In some cases, an effective transgenic crop-protection technology can control pests better and more cheaply than existing technologies. For example, with Bt engineered into a corn crop, the entire crop is resistant to certain pests, not just the part of the plant to which Bt insecticide has been applied. In these cases, yields increase as the new technology provides more effective control. In other cases, a new technology is adopted because it is less expensive than a current technology with equivalent control.

There are cases in which new technology is not adopted because for one reason or another it is not competitive with the existing technology. For example, organic farmers apply Bt as an insecticide to control insect pests in their crops, yet they may consider transgenic Bt crops to be unacceptable.

Improved nutritional value:

Health-conscious consumers are compelling farmers and seed companies to improve the overall nutritional quality of their products. Extensive medical, biochemical and epidemiological research points to specific plant-produced substances (phytochemicals), as well as classes of phytochemicals that offer specific health benefits. Fruits and vegetables are a major source of beneficial phytochemicals Phytochemical families with clearly beneficial health properties include glucosinolates found in the brassica vegetables including broccoli; carotenoids, such as the tomato fruit pigment lycopene, found in many plant families; flavonoids, such as the isoflavones found in soybeans; and the anthocyanins and flavonols found in many fruits and vegetables.

Some foods containing consistently higher levels of these and other plant nutrients should be available through conventional breeding methods within 10 years. The natural variation that would provide the basis of health-enhanced varieties may be present already in breeding populations. Compared with traditional breeding strategies, the application of biotechnology to improve phytonutrient levels in whole foods is more difficult due to the complex array of potentially important chemicals and the complexity of the underlying biosynthetic pathways. The nutritional content of fruits and vegetables could be greatly enhanced through conventional breeding as well as biotechnology. Antioxidants, such as glucosinolates in broccoli and carotenoids in squash, have proven health benefits.

 

Flavor and color:

The ability to transgenically manipulate color intensity and hue was demonstrated more than 10 years ago. In flowers, the altered expression of the enzymes of flavonoid biosynthesis yielded novel floral pigmentation patterns. Such approaches have not been applied to fruits yet, but the potential exists.

Anthocyanins are the pigments responsible for color in many fruits, such as grapes and strawberries. Deeply colored fruits are generally more desirable to consumers. Further, anthocyanins and related flavonoids have antioxidant properties that reduce the risk of cardiovascular disease and cancer. Fruits with consistently higher levels of anthocyanins, produced through genetic modification, could reach the supermarket within 15 years. These will likely be produced by altering the expression of whole biochemical pathways rather than through modulation of specific enzymes.

Improved flavor is of major interest to consumers, but it does not receive significant attention from breeders, who work largely to improve production and durability during postharvest distribution. The complexity of flavor — which includes a balance between sweetness and acidity as well as the compounds that give products their characteristic taste — has discouraged the pursuit of biotechnological approaches to flavor improvement.

Biotechnological efforts to improve sweetness have met with little success so far. In some cases, an increase in sweetness leads to a decrease in size that is unacceptable in the marketplace. In addition, attempts to increase sweetness by expressing nonsugar, sweetness-enhancing proteins such as monellin have been frustrated because their compounds bind to cellular proteins and are subsequently not available to the sensory system.

ENVIRONMENTAL BENEFITS:

Improvements in water quality could prove to be the largest single benefit of GE crops, the report says.  Insecticide use has declined since GE crops were introduced, and farmers who grow GE crops use fewer insecticides and herbicides that linger in soil and waterways.  In addition, farmers who grow herbicide-resistant crops till less often to control weeds and are more likely to practice conservation tillage, which improves soil quality and water filtration and reduces erosion.

However, no infrastructure exists to track and analyze the effects that GE crops may have on water quality.  The U.S. Geological Survey, along with other federal and state environmental agencies, should be provided with financial resources to document effects of GE crops on U.S. watersheds. 

 The report notes that although two types of insects have developed resistance to Bt, there have been few economic or agronomic consequences from resistance.  Practices to prevent insects from developing resistance should continue, such as an EPA-mandated strategy that requires farmers to plant a certain amount of conventional plants alongside Bt plants in "refuge" areas.

Benefits for developing countries

Genetic engineering technologies can help to improve health conditions in less developed countries. Researchers from the Swiss Federal Institute of Technology’s Institute for Plant Sciences inserted genes from a daffodil and a bacterium into rice plants to produce “golden rice,” which has sufficient beta-carotene to meet total vitamin A requirements in developing countries with rice-based diets. This crop has potential to significantly improve vitamin uptake in poverty-stricken areas where vitamin supplements are costly and difficult to distribute and vitamin A deficiency leads to blindness in children.