Bioengineering Plants and Genetically Modified Foods





"I have neither given nor received unauthorized aid on this assignment"


November 18, 2002






Lauren Hinson

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With all the importance given to genetics research, it seems somewhat curious that information about plant genetics rarely seems to surface. So much is known about human genetics due to the Human Genome Project and other projects, animal genetics has been thoroughly researched, and even the genetic information for tiny microorganisms has been investigated. Yet it seems that a crucial part of life, the plant, is being ignored in this quest for bioengineering knowledge. ARE there research projects searching for information about plant genetics? Absolutely.

Part A: Bioengineering and Genetically Modified Plants

Genetically modified plants have been around for millennia, for as long as people have been cultivating plants. Historically, genetic modifications have been the results of trial and error cross breeding based on Mendelian characteristics (Formanek 2001) where seeds are kept from the best plants to plant the following year in order to reproduce favorable traits. Through these traditional methods, numerous varieties of plants have been modified to grow bigger, taste better, and last longer. Wild inedible plants have been cultivated into common household varieties, like the common tomato from a plant with small marble-like fruit and the sweet white and yellow corn varieties from the weedy teosinte plant which had an ear barely an inch long (Ackerman 2002). The problem however, with the traditional methods of cultivation is that they take time, many years and multiple growing seasons before the desired results are evident, if at all (Formanek 2001). More modern techniques that directly alter the genetic content of a plant are much faster in obtaining the desired results, where desired traits are sometimes evident in a single crop cycle (Thompson 2000). "The advent of genetic modification has enabled plant breeders to develop new varieties of crops with a wide range of

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characteristics....and brings with it a huge potential for further development" (Royal Society 1998).

Genetically modified, or transgenic, plants are any plant that contains any gene or genes that have been artificially inserted into the plant instead of being acquired by the plant through pollination (http://www.colostate.edu/programs/lifesciences/transgenic crops.html). Many different types of genes can be implemented and expressed through genetic modification and bioengineering. The bulk of genetic modifications involve food related crops. Scientists can take almost any gene from almost any species and insert that genetic information into almost any species of plant. For example, several different types of plants (corn, soybeans, cotton et al) have been rendered herbicide resistant by transforming them with a natural bacterial enzyme, and some plants (corn, tobacco, cotton et al) have been modified to be insect resistant via the introduction of genes for an insect infecting protein naturally produced by Bacillus thuringiensis (Bt) (Dhawan 1999). In another example from India, where excessive salt buildup in important breadbasket regions has left the soil contaminated and useless, researchers have developed strains of salt resistant crops by over-expressing a single gene (Dhawan 1999). Further examples include "Roundup ready" strains of corn, soy beans, and other staple crops. These varieties of corn, cotton, and soybeans have been genetically modified to resist common herbicides and other chemicals used to kill invasive weeds in crop patches, like the well known Roundup (thus the name) (http://www.colostate.edu/programs/lifesciences/ transgeniccrops. html).

There are several different methods by which scientists isolate and transfer desired genes to a plant. One of the common methods for giving plants new genetic

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characteristics is via plasmids. After the desired gene is isolated from another plant or species, the new deoxyribonucleic acid (DNA) is linked to a genetic material called a plasmid, which acts like a taxi that carries genes from place to place. The plasmids are then absorbed by a bacterium that attaches itself to a plant cell and frees the plasmids, after which the DNA migrates to the chromosomes to be permanently integrated into that cell's genetic information. The information is then passed on through reproduction of that plant cell. Another method of genetically engineering plant genes is, subsequent to isolating the desired gene, the DNA is "painted" on to microscopic metal particles, loaded into a "gene gun," and fired as microscopic projectiles at plant cells growing in laboratory cultures. These miniature "bullets" penetrate the cell wall, at which point the new genetic material is washed off the particles and integrated into the chromosomes as before (Thompson 2000). A third and newer yet little used method involves reparation of a cell's own mutated or undesired genetic information as opposed to introducing foreign genes. To do so incorporates a DNA and ribonucleic acid (RNA) combined molecule called a chimera. The DNA enables the hairpin shaped chimeras to home in on a specific gene while the RNA stabilizes the molecule. Though poorly understood, a cell treated with the chimeras uses its own DNA repair mechanisms to swap some of the DNA of the chimera with a segment of the cell's natural gene (Travis 2000). Continuing research involving the various ways

There has been some question in scientific and public sectors as to the effects of the bioengineered genes on the behavior of the plants themselves. Concerns have been raised that the expression of genes inserted/altered by genetic modification might be easily lost, thereby returning the plant to its non-modified state (Royal Society 1998).

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Researchers generally adhere to the fact that, while research produces genetically stable and unstable results, plants chosen for widespread cultivation are selected based on the stability and efficacy (Royal Society 1998) through at least three years of field trials and investigation. Other questions have been raised about the likelihood of pleiotropic1 effects arising from the insertion of foreign genes into the chromosomes of the plant. One likely scenario concerning pleiotropic expression might be the results of attaching a gene with a strong promoter next to a toxin gene present but previously unexpressed. The insertion then might trigger activation of the toxin gene therein producing hazardous toxins in addition to the novel gene product (Royal Society 1998).

The processes of genetically engineering plants have come a long way since the introduction of the first GM crops in the early 1990s. There is, however, quite a bit more information waiting to be gleaned from plant genetics. Some of the research is incomplete or has been halted due to a negative response from society, but much of the research continues. The advent of further plant bioengineering holds only promise for the future of the field, with the possibility of tremendous benefits for all of society.

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Part B: Genetically Modified Plants and the General Public

One of the hottest, and most controversial and public, topics in genetics today is the research involved in bioengineering plants used for food purposes. Genetically modified (GM) plants are any plant that contains any gene or genes that have been artificially expressed or inserted into the plant instead of being acquired by the plant through pollination (http://www.colostate.edu/programs/lifesciences/transgeniccrops. html). The first GM food staple was introduced in 1994 as the "Flavr Savr" tomato. This strain of tomato was heralded as being able to ripen slower, having a longer vine life, and being of a better quality in winter production (Formanek 2001). In the following decade, many varieties of crop plants have been introduced and are used all over the globe, including but not exclusively varieties of corn, squash, canola, soybeans, and cotton, as well as potatoes, bananas and various other fruits (Ackerman 2002).

Since their introduction and evolution in and since 1994, widespread cultivation of GM crops has revolutionized global food markets. In all, about two thirds of processed foods in United States supermarkets contain genetically engineered corn, soybeans, or other crops (Formanek 2001). Foods that one usually might not consider having genetically modified ingredients do, processed foods like pizza, chips, cookies, ice cream, salad dressings, soft drinks, even baking powder (Ackerman 2002). The biotech products that go into these foods come from 130 million cultivated acres worldwide, from places like Argentina, Canada, South Africa, Germany, and China. In the United States, over 88 million acres were planted in bioengineered crops in 2001, 25 times the total acreage of 3.6 million planted in 1996 (Ackerman 2002). In the central piedmont region of North Carolina, usage is fairly limited to about two transgenic crops (65% of acres of cotton planted are "Bollgard" cotton, 80% of acres of soybeans planted are "Roundup Ready"), with at least two more on the verge of widespread cultivation (transgenic tobacco, Roundup Ready corn) (Spears 2002).

The debate over genetically modified food began almost as soon as scientists learned how to alter the genetic makeup of plants in the early 1980s. "The public reaction to genetically modified foods has been astonishing" (Kenderlerer 1999). Because of public denouncements of GM foods by such public figures as the Prince of Wales and by scientists in the public arena, the general public has adopted a fairly

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negative attitude toward bioengineered crops with especially strong opposition in Europe and Japan. Opponents of biotechnology in the agro-food chain have effectively used the communication tools of the information technology revolution to shape opinions.

In fact, they have built their assault around the term 'GMO'2 as a virtual poison label, demanding GMO labeling and leading a call for products guaranteed as 'non-GMOs' or 'GMO-free'. This demonization of [agricultural] biotech as 'Frankenstein foods' ...has permeated the media (Brookins 2000),

and therein, the public. One other cause for public debasement of bioengineered foods is incidents involving those foods, like the "Starlink" corn fiasco. After Aventis's (a biotech research firm) introduction of the Bt corn dubbed "Starlink" in the late 1990's, the strain was determined to contain the allergen Cry9C protein (this protein is heat resistant and able to withstand the acids in the human stomach) and, though approved for animals, was not approved for human consumption. However, due to cross-farm contamination of non-Cry9C corn, traces of the "Starlink" variety were found in tacos processed by the Kraft Corporation resulting in a public controversy (Kaufman 2000). Due to the allergen containing nature of the corn and its presence in a human food source, Kraft recalled all taco shells and related corn-containing products, and Aventis recalled all of the "Starlink" strain (Formanek 2001). Because of the vehement anti-GMO reaction on the part of the general public, many GMO-containing foods and food products have been pulled from supermarket shelves. However, producers of GM crops are not being discouraged. Concerning public opinion, Douglas Boisen says:

As a producer, I get very frustrated with what appears to be public concern over bio-technology. I blame the radical environmental groups for the misinformation that is offered and the media for playing it up so it sells better. The questionable reports get a lot of attention, but when was the last time you read an article about the benefits? This story is not being told (2000).

The public reaction to bioengineered foods has not been completely unwarranted; some of the concerns are highly valid but somewhat unquantified. One of the main concerns about bioengineered foods is that altering the genetics of a plant may introduce new allergens into the food chain. Allergies occur when the body reacts to particular

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proteins, and some fear that by changing the genetics of the plant, more of these protein-producing genes will be expressed (Pollack 2002). Researchers on the other hand assure that "the new technology doesn't make the food more likely to cause allergies" (Thompson 2000), and that furthermore, bioengineering will cause plants to have fewer allergies by implanting a backwards copy of the protein-producing gene in question or eliminating it altogether (Pollack 2002). Some consumers also worry antibiotic resistant genes in GM foods. Commonly, antibiotics are used for marker genes, and the issue is whether or not these genes are transferable from the GM plant DNA to the bacteria in the stomach of the consumer. Most likely, however, transfer would only occur in consumption of the unprocessed GM plant because processing of the food typically causes the DNA to be degraded to a harmless state (The Royal Society 1998). The results of the antibiotic-resistant genes invading the bacteria of the stomach and intestines would be illnesses like diarrhea that would be able to withstand an oral dose of the antibiotic in question (http://www.colostate.edu/programs/lifesciences/transgeniccrops. html). Other concerns include ingesting foreign DNA, the promoter genes used to express inserted traits, and altered nutrient levels. Neither of these three has any conclusive effect on human consumers; the first is non-relevant because any foreign DNA is destroyed by the body's natural defense mechanisms, the second is negated for the same reasons, and the third has yet to be proven in multiple research projects (http://www.colostate.edu/programs/lifesciences/transgeniccrops.html). Despite, and perhaps in spite of, these concerns, many people have chosen to embrace bioengineered foods because of their many benefits rather than reject them because of un-quantified and sketchy (at best) concerns and risks.

The results of public reaction to bioengineered foods have led to increased legislation regarding the GM foods on the market. Currently, bioengineered foods are regulated by three federal organizations: the Food and Drug Administration (FDA), the Environmental Protection Agency (EPA), and the United States Department of Agriculture (USDA). In January 2001, the FDA:

Proposed mandatory rules ... that would tighten the scrutiny of bioengineered foods. The rules would require that manufacturers of plant-derived, bioengineered foods and animal feeds notify the FDA at least 120 days before the products are

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marketed. Furthermore, the FDA has issued guidelines for companies wanting to label their products to indicate that a food or feed has or has not been developed using bioengineering methods (Formanek 2001).

The USDA's Animal and Plant Health Inspection Service carefully monitors genetically modified plants for potential risks to the agricultural environment, while the EPA regulates the pesticides used on all crops, including those introduced into plants via biotechnology (Thompson 2000). A concern among some people is the question of labeling or not labeling GM foods. Although some activists are petitioning for the labeling, the Federal government has yet to pass definite legislation stating guidelines for labels, maintaining that "there is no strict distinction in the genetically modified plants versus the conventional plants, so labeling them is a non-issue" (Dunn 2000).

Although resistance to bioengineered plants has been very high in Europe and Japan, Americans have generally been more, but not completely, accepting of the GM plants.

Furthermore, it is important to note that Europe is completely self-sufficient in meeting food needs, and that they also have a surplus. This may account for some of the European reluctance to fully embrace bioengineered foods (Dhawan 1999).

Yet despite a somewhat negative public reaction to bioengineered foods, professionals, researchers, and producers alike continue to herald the benefits of bioengineering foods, and there are many. One of the most beneficial of these is a marked reduction of pesticide and insecticide usage among farmers who produce GM crops. Because the plants have been genetically altered to be resistant or self-detrimental to such things as rootworms, borers, beetles, and other invasive parasites, the farmers generally have to use little or no pesticide to rid their fields of these pests. "Roundup Ready" strains of crop plants like soybeans are noted as reducing the uses of herbicides to kill unwanted plants and weeds. The reduction of pest and weed killers in turn reduces

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runoff of these chemicals into groundwater and water supplies, and also reduces soil pollution (Dhawan 1999). Genetically altering crops leaves researchers more control and precision over what characteristics are being bred with more speed than natural processes (Thompson 2002). GM crops have higher production rates than traditional crops, resulting in more produce per acre with less waste (Formanek 2001). Another benefit of GM crops is higher nutritional content in some varieties, like sweet potatoes and rice.

The uses of bioengineering plants have so many possible and beneficial applications that it is almost impossible to discount their value. There are problems in many third-world and developing nations, like Asia, in which serious health problems result from dietary deficiencies; a lack of vitamin A causes blindness in a half million children each year, and a lack of iron causes severe anemia in many women and children (Boisen 2000). Scientists are developing a strain of rice, a staple crop for many cultures, which will have higher levels of these and necessary nutrients. This "golden rice" will join with essential-nutrient enriched potatoes to help end dietary deficiencies in poor countries (Chaudhury 1999). In some parts of the world, in river floodplains and breadbasket regions, there has been a buildup of salt that renders prime farmland useless because most plants are unable to tolerate highly salty environments. By genetically engineering plants to be salt-resistant via the over-expression of a single gene, farmers can utilize the previously unusable land to grow important staple foods and help alleviate food shortages in those regions affected (Dhawan 1999). In Africa, banana seedlings that have been bioengineered to be disease resistant have provided families that formerly couldn't produce sufficient food with a surplus. Likewise, many African farmers look to the advent of genetically engineered varieties of the disease-prone sweet potatoes to help alleviate shortages in this food staple (Ackerman 2002). In Hawaii, papaya farmers are singing praises for genetically altered papaya trees. Up until 1998, the papaya ringspot virus3 threatened the livelihood of many of these farmers. In that year the farmers were given papaya seeds that had been bioengineered to resist the disease, and there have been no problems with the disease since their planting (Ackerman 2002). Another project in

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development is the elimination of food allergens. Statistically, two percent of adults and eight percent of children in the United States have food allergies, resulting in hives, nausea, stomach illnesses, and sometimes severe anaphylactic shock. Through genetic alterations, the genes that produce allergy causing proteins could be removed, this resulting in fewer allergies all over the world (Pollack 2002). Other projects involving genetically modified crops that are still in the research stages include genetically altering tobacco plants to be nicotine-free without removing any of the flavors, a previous concern, (http://www.colostate.edu/programs/lifesciences/transgeniccrops. html) and modifying sunflowers to be resistant to the crop destroying "white mold"4. Perhaps one of the most exciting projects involving bioengineering plants is the development of "edible vaccines" for infectious diseases like cholera, diarrhea, and Hepatitis B. These vaccines would be inserted into the genetic material of the plant, where the inactivated virus would trigger resistance in the consumer when eaten (Formanek 2001). This is especially promising for poorer countries where refrigeration necessary for preserving the vaccines and proper sterilization of needles are scarce and many children would not otherwise receive these and other vaccinations.

The future of bioengineering plants is very bright. If the consumers, however, refuse to embrace these new technologies, then the general public worldwide will miss out on wonderful opportunities. Some people might argue that by bioengineering foods, scientists are "playing God" and others argue that it is unethical to change the genetic nature of these plants. However, as Carole Brookins says, "there is no sharper contrast today in terms of widespread public acceptance of biotechnology's benefits in pharmaceuticals and industrial products, and the widespread public fear of biotechnology's dangers in agriculture and food production" (2000). Can society not accept the idea across its spectrum of applications? The possibilities of bioengineering have only been tapped and people are already rejecting them. The answers to so many problems in society today, like the rocketing global populations and the problems therein, may lie with the realm of bio engineering genetics. Is this ethical? Maybe not. Will it benefit people? Definitely.

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Works Cited Part A:

Ackerman, J. (2002 May). Food: How Safe? How Altered?. National Geographic Magazine, 201(5), 2-51.

Dhawan, V. Food Security: can designer crops meet new challenges?. The Business Line, 6 December 1999.

Formanek, R. (2001, March-April). Proposed rules for bioengineered foods. US Food and Drug Administration Consumer Magazine, 35(2). http://www.colostate.edu/programs/lifesciences/transgeniccrops. html

Royal Society, The. (1998 September). Public Statement: Genetically modified plants for food use. Retrieved October 24, 2002 from: http://www.royalsoc.ac.uk/files/statfiles/document-56.pdf

Thompson, L. (2000, January-February). Are bioengineered foods safe?. US Food and Drug Administration Consumer Magazine, 34(1).

Thompson, L. (2000, January-February). Methods for Genetically Engineering a Plant. US Food and Drug Administration Consumer Magazine, 34(1).

Travis, J. (1999). New gene-altering strategy tested on corn. Science News (6 May 2000). Retrieved 21 October from: http://www.findarticles.com/cf_dls/m1200/19_157/62724332/print.jhtml


Works Cited Part B:

Ackerman, J. (2002 May). Food: How Safe? How Altered?. National Geographic Magazine, 201(5), 2-51.

Boisen, D. D. (2000, 24 February). Biotechnology: a farmer's perspective. Address.

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Speech to USDA Outlook Forum 2000, Arlington Va.

Brookins, C. L. (2000, 24 February). Biotechnology and international trade issues. Address. Speech presented to USDA Outlook Forum 2000: Panel on the Future of Bio-Engineered Farm Products, Arlington, Va.

Chaudhury, A. (1999). Do we need trangenics?. The Business Line, 6 December 1999

Dhawan, V. Food Security: can designer crops meet new challenges?. The Business Line, 6 December 1999.

Dr. Jan Spears, NCSU Crop Sciences. (Personal communication, 11 November 2002).

Dunn, M. V. (2000, 24 February). Federal government perspective on regulatory issues. Address. Speech presented to USDA Agricultural Outlook Forum, Arlington, Va.

Formanek, R. (2001, March-April). Proposed rules for bioengineered foods. US Food and Drug Administration Consumer Magazine, 35(2).

http://www.colostate.edu/programs/lifesc iences/transgeniccrops. html

http://www.extento.hawaii.edu/kbase/crop/Type/papri ng.htm

http://www.heftyseed.com/white-swm.html

Kaufman, M. (2000, September 3). Biotech critics cite unapproved corn in taco shells. The Washington Post, p. A2.

Kinderlerer, Dr. J. (1999) Public reaction to genetically modified foods in the UK. Retrieved 9 November 2002 from: http://www.cid.harvard.edu/cidbiotech/comments/comments34.htm

Pollack, A. (2002, 15 October). Gene jugglers take to fields for food allergy vanishing act. Retrieved 21 October from: http://www.nytimes.com/2002/10/15/health/genetics



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Royal Society, The. (1998 September). Public Statement: Genetically modified plants for food use. Retrieved October 24, 2002 from: http://www.royalsoc.ac.uk/files/statfiles/document-56.pdf

Thompson, L. (2001, January-February). Are bioengineered foods safe? US Food and Drug Administration Consumer Magazine, 34(1).



1 Pleiotropic: (of a gene) having a effect simultaneously in more than one characteristic of the offspring.

2 GMO: genetically modified organism

3 Papaya ringspot is a disease of the papaya tree that leaves string-like leaves and reduced fruit yield with large, slightly shrunken green rings on the fruit. The tree eventually develops a small leaf canopy due to small and stunted leaf development but rarely die (http://www.extento.hawaii.edu/kbase/crop/Type/papring.htm).

4 White mold is serious problem for sunflower farmers in some areas. This is a white cottony fungus that is spreas through spores and kills any plant from the point of growth and up (http://www.heftyseed.com/white-swm.html).