University of Kentucky College of Agriculture, Food and Environment PPA-47 Cooperative Extension Service

Genetically Engineered Crops Emerging Opportunities Paul Vincelli, Plant Pathology

Background Information The genetic modification of plants is nothing new. Nature genetically Biotechnology is “any technological modifies organisms in bizarre and application that uses biological systems, remarkable ways (see 1: Sweet Potato, living organisms, or derivatives thereof, Genetically Engineered by Nature and to make or modify products or pro- 2: Is This Genetically Engineered Corn?). cesses for specific use.”1 This definition Humans have guided genetic changes encompasses many, many applications, in crops for thousands of years through including traditional ones such as fer- simple selection. More recently, plant mentation of alcoholic beverages. breeders have employed a variety of In certain biotech crops, their genetic more advanced breeding techniques. material (DNA) has been purpose- In all instances, the breeder is seeking Sweet potato, an example of a natural GMO fully manipulated in the laboratory. crops with improved plant performance. Photo courtesy of Steve Patton These genetically engineered crops are Improved performance may in- Sweet Potato, Genetically Modified often called “GMOs,” an acronym for clude improved nutritional qualities, by Nature. Transfer of genes from one “genetically modified organisms.” These 1 increased yield, more efficient use of organism to another seems bizarre until one GMOs are the focus of this publication. fertilizer or water, tolerance to stresses realizes that this process happens regularly DNA is merely chemical information, like drought and heat, disease resis- in natural ecosystems. Gene transfer is one like words in a book. Just as we can use tance, etc. Breeders seek improved of the ways that Nature creates biodiversity. a word processor to edit sentences or crop performance in order to provide For example, scientists recently reported that to transfer them from one book into benefits to farmers, consumers, and the sweet potato, a crop many of us enjoy every another, laboratory techniques allow environment. Thanksgiving, naturally contains at least four us to edit DNA or transfer it from Some breeding techniques cause genes from a soil-dwelling bacterium. Ex- one organism into another. In and of substantial genetic changes, including amples of natural gene transfer are common themselves, words are not poisonous. some very well accepted, conventional in the scientific literature, and more are be- Similarly, in and of itself, DNA is not breeding techniques. Commercial ing discovered regularly as science advances. poisonous. Changing the words in a genetically engineered crops are de- book changes how it reads. Similarly, signed so that they generally have very changing the DNA of an organism can limited and precise genetic changes. In change its appearance or function. fact, the genetic changes in genetically All foods contain DNA. We eat engineered varieties typically have less DNA with every meal. Eating DNA is impact on the crop’s metabolism than not dangerous. Consuming DNA of all other crop-improvement techniques. any crop or animal—whether they are Many will be surprised to learn that traditional varieties or biotech ones— much of what they know about genetic does not cause that DNA to be inserted engineering is becoming obsolete. The into our own DNA. If DNA in our food most up-to-date methods of genetic somehow inserted itself into human engineering can produce remarkably DNA, our bodies would contain genes modest and precise genetic changes in Genetically engineered corn is still just corn. from the foods people have eaten for plants. And they can do so in a way that Photo courtesy of Chad Lee thousands of years. But we don’t find leaves no trace of “foreign DNA.” This wheat genes or rice genes in humans Is This Genetically Engineered Corn? new technique is called because the DNA naturally present in genome edit- You can’t tell by looking at it. Geneti- , and it can produce genetic changes 2 our foods does not insert itself into hu- ing cally engineered corn is corn, pure and in specifically targeted genes, and man DNA. simple. There are no “Frankenfoods,” except those changes may be as minimal as a those that Nature has created on her own. 1 From the UN Food and Agriculture Organization, http://www.fao.org/docrep/014/i1905e/i1905e00.pdf.

Cooperative Extension Service | Agriculture and Natural Resources | Family and Consumer Sciences | 4-H Youth Development | Community and Economic Development one-nucleotide change. This process FDA for human use as long ago as 1982. netic engineering were developed by is like changing one letter in an entire Numerous medications are based on studying the creative things Nature book. A change of one nucleotide is the genetic engineering, and more such does with DNA. most precise and minimal change that medications are coming. For example, a `` Are genetically engineered crops is physically possible in a plant’s DNA. promising, potentially life-saving exper- safe to eat? Such a change is so minimal that scien- imental vaccine for Ebola is genetically ƒƒ Genetically engineered crops grown tists cannot distinguish such a change engineered. in the USA are subjected to scrutiny from a mutation that occurred natural- Which genetically engineered for safety to humans and to the en- ly. Thus, genome editing allows one to crops are grown in the USA? Most vironment. Three federal agencies engineer plants in a minimally invasive genetically engineered crops are not are involved in evaluating the safety way, leaving no trace of laboratory consumed directly by humans. In the of genetically engineered crops: the manipulation. For this reason, genome USA, most are grown for animal feed, US Department of Agriculture, the editing complicates the regulatory for processing, or for fuel production. US Food and Drug Administra- picture. For example, if a crop variety Certain varieties—though not all—of tion, and the US Environmental engineered by genome editing cannot the following crops grown in the USA Protection Agency. In contrast to be distinguished from one that was not are derived from genetic engineering: genetically engineered crops, non- engineered, can it be regulated? Should ƒƒAlfalfa engineered (non-GMO) crop variet- it be regulated? ƒƒApple (trademarked Arctic® Apple) ies typically receive very little to no Wise breeders use the best method ƒƒCanola formal evaluation by government available to solve particular problems. ƒƒCorn (both field corn and sweet corn) agencies. Genetic engineering tech- In cases where traditional breeding ƒƒCotton nologies are advancing very rapidly. techniques provide an adequate level of ƒƒPapaya Consequently, in July 2015, the fed- crop improvement, these are preferred ƒƒPineapple (trademarked ‘Rosé Pine- eral government began a process to to techniques that are more technically apple’) review and update the oversight of demanding or expensive. For example, ƒƒPotato (trademarked ‘Innate® Po- genetically engineered crops. conventional breeding has made more tato’) ƒƒ Many scientific experts worldwide ƒ progress in creating drought-tolerant ƒSoybean agree that genetically engineering ƒ corn than genetic engineering, at least ƒSquash a crop generally presents no new ƒ for now. However, if a breeding objec- ƒSugar beet health risks that cannot also arise tive cannot be met using conventional In addition, certain genetically engi- from conventional plant breed- methods, a genetically engineered ap- neered apple and potato varieties are in ing. As explained in footnote 2, proach makes sense to most scientists. the process of commercialization, and recombinant DNA is quite natural (See Benefits of Genetic Engineering on other genetically engineered crops are and common in our foods, and page 8 for examples.) Most crop scien- likely to be commercialized in the near has been so for thousands of years. tists think that the wise use of genetic future. If you wish to avoid all foods What matters is not the presence engineering will help reduce food inse- derived from genetic engineering, you of recombinant DNA, but what the curity and make food production more can buy certified organic foods or those DNA does in the plant. You can sustainable. specifically labelled to be GMO free. read in-depth about what scientific Genetic engineering has been part organizations say on the topic of of American life for decades. Geneti- Concerns about Genetic genetic engineering and food safe- cally engineered corn has been grown Engineering ty in the file named Quotes from in the USA since 1996. Most cheeses in `` Is genetic engineering natural? Science Academies on Consuming the US are made using genetically en- Nature commonly and naturally GMO Crops, online at https:// gineered enzymes approved in 1990 by produces dramatic changes in the kentuckypestnews.wordpress. the U.S. Food and Drug Administration genetics of plants.2 An example is de- com/2015/03/31/consumption-of- (FDA). High-quality enzymes for mak- scribed in 1: Sweet Potato: Genetically genetically-engineered-gmo-crops- ing cheese are produced by genetically Engineered by Nature. Many more ex- examples-of-quotes-from-position- engineered bacteria in fermentation amples are described in the scientific papers-of-scientific-organizations/. tanks instead of obtaining enzymes literature. This natural “genetic turbu- ƒƒ Certain genetically engineered from the stomachs of dead calves. Insu- lence” often seems bizarre. However, traits can actually improve the safe- lin for diabetics produced by genetically these are merely some of the ways ty of food. See 3: Improving Food engineered bacteria was approved by that Nature creates biodiversity. In Safety through Genetic Engineering. fact, our laboratory techniques of ge-

2 These natural changes include diverse mutation; insertion, deletion, and duplications of jumping genes or other genetic sequences; gene duplication; "cutting and pasting" that results in inversion, translocations, and novel gene assemblies; shuffling of gene fragments; chromosomal duplication; transfer of genes and gene fragments between unrelated organisms; and incorporation of virus genes into the plant's own genetics. All of these are instances of Nature itself creating recombinant DNA. Although recombinant DNA is often thought of as a human invention in the laboratory, our crops contain a surprisingly large amount of "all natural" recombinant DNA.

2 Improving Food Safety through Genetic 3 Engineering. It surprises some to learn that engineered crops can actually be safer than conventional foods. For example, corn grain can be naturally contaminated by mycotoxins, which are natural toxins produced by fungi. Fumonisins are the most common mycotoxin found in corn in Kentucky and many other re- gions throughout the world. Aflatoxins are less common, but when they occur, they can cause serious disruption to grain marketing, because of their high toxicity. Both mycotoxin families pose health risks to livestock. Pigs and horses are highly sensitive to poisoning by fumonisins. Aflatoxins in the feed can be very hazardous to chickens. In addition, both mycotoxin families pose risks to human health. In certain countries where corn meal is a significant part of the daily diet, maternal exposure to natural fumonisins Close-up of Aspergillus ear and kernel rot of corn. The fungus that causes this disease can produce in contaminated corn during pregnancy has aflatoxin contamination. been associated with increased frequency of Photo by Paul Vincelli

birth defects called neural tube defects. Long- tain insects. This, in turn, means that there are term consumption of fumonisin-contaminated fewer wounds on the kernels. Fewer wounds corn is also considered a risk factor for esopha- often means less invasion of the grain by my- geal cancer. Aflatoxins are very potent toxins, cotoxin-producing fungi. You can learn more causing a wide variety of effects. They are also about Bt and corn mycotoxins at http://grain- very potent, natural carcinogens of the liver. crops.blogspot.com/2013/08/gmos-and-corn- One of the ways corn growers can reduce mycotoxins.html. Other genetic-engineering the level of mycotoxin contamination is through traits near commercialization will help improve the use of varieties with a Bt trait (See Text Box food safety in other ways. Fusarium ear and kernel rot of corn. Fungal #10: Plants that Fight Back Against Insects). Bt growth in the kernels can result in contamina- traits often reduce feeding on the grain by cer- tion by fumonisins. Photo by Paul Vincelli

ƒƒ There is ongoing scientific discus- ƒƒ University of Kentucky scientists on the flowers of a wild relative. sion over a particular application of always remain open-minded to new This concern applies even to genes genetic engineering: the engineering discoveries. If credible, validated re- spreading from conventional, non- of crops to be tolerant to the weed- search raises food-safety concerns, genetically engineered varieties. killer called glyphosate. Numerous these will quickly become part of However, there is greater concern studies show no significant health our Extension programming. This is over pollen from genetically engi- risk to humans from government- true whether the crop of concern is neered crops. This is because genes approved uses of glyphosate. conventional or biotech. that are foreign to native plant spe- cies may be introduced through However, some experts do raise `` Can genetic material from geneti- questions about the safety of long- the pollen. Such gene spread could cally engineered crops spread in negatively impact biodiversity in term exposure glyphosate in the Yes, potentially so. This is a pollen? some instances. No such cases diet. This is one reason some people legitimate concern, although there are have been documented to date, want products derived from geneti- ways to reduce this risk. Concerns are: though it is a legitimate concern, cally engineered crops to be labeled. ƒƒ Genetically engineered genes and one that we should minimize For more on this, see 4: Crops Toler- may move into wild relatives of whenever developing or using ant to a Weed-Killer. crop plants when pollen from the genetically engineered crops. genetically engineered crop lands

3 ƒƒ Genetically engineered genes like these highlight a significant investment through litigation may move into fields of producers challenge for the use of those against farmers. A few such instanc- growing crops intended to be free genetically engineered traits that es have resulted in negative public- of genetically engineered genes. may spread in pollen or seed. These ity for the patent-holder. There is some evidence that this instances stress the importance of ƒƒ From a producer’s perspective, has happened in traditional variet- minimizing these risks. paying the cost of legally using a ies of corn grown by smallholders `` Do patents on seeds or genetic patented genetically engineered trait in Mexico, the historic origin of traits cause concern? There are can increase cost of crop production. corn. Although there is still some several concerns. More importantly, patents can re- scientific uncertainty that this has ƒƒ The majority of acreage planted to strict seed-saving and seed-sharing. happened, many scientists are con- genetically engineered crops in the ƒƒ In developing countries, resource- cerned about the possibility. Small- USA is—or was, at one time—pat- poor farmers and indigenous peoples holder farmers in Mexico are also ented by multinational corpora- often prefer seed that is not geneti- extremely concerned about this tions. Federal laws allow for such cally engineered, particularly if such risk. See 5: Protecting Cultural Heri- patents, as patents help protect the seed prohibits seed saving and shar- tage. There is evidence of spread of investment of those that develop ing. See 6: Patents Can Inhibit Seed transgenic seed into a canola field new genetic technologies. Farmers Saving and Sharing. in Australia intended for organic may not save seed from a patented ƒƒ In developed nations, many farm- certification. This resulted in very genetically engineered crop unless ers choose to pay for the genetically unpleasant litigation between for- they pay a fee. Patent-holders some- engineered seed because they value merly friendly neighbors. Instances times aggressively protect their

Crops Tolerant to a Weed Killer. The engineering additional resistance to the her- Numerous studies show no significant health 4 genetically engineered crops that have bicides 2,4-D or dicamba allows for control risk to humans from government-approved uses received the most negative attention are of glyphosate-resistant weeds. Farmers cur- of glyphosate. However, a small number of ex- those engineered to be tolerant of the weed- rently need these herbicides, but it means that perts raise questions about possible long-term killer glyphosate (found in products like some producers must now use more herbicides health impacts of trace amounts of glyphosate Roundup® herbicide). Spraying glyphosate than before to control weeds. This is some- in the diet. In March 2015, a branch of the World on plants normally kills almost all plants- times referred to as a “pesticide treadmill.” Health Organization categorized glyphosate -crops as well as weeds. However, a single Weeds resistant to herbicides are not as a “probable human carcinogen.” However, gene from a bacterium can be inserted into unique to glyphosate. Herbicide-resistant this judgement has been rejected by numer- crops to make them tolerant to this herbicide. weeds occur even in crops that are not ge- ous independent regulatory bodies, including Glyphosate-tolerant crops are perceived netically engineered. Furthermore, herbicide the U.S. Environmental Protection Agency and differently by different people. Many farmers tolerance in crops is not just due to genetic the European Food Safety Authority. The World appreciate glyphosate-tolerant crops because engineering. There are commercial, herbi- Health Organization also recently concluded that weed control is easy, effective, and inexpensive. cide-tolerant crops created by conventional “...glyphosate is unlikely to pose a carcinogenic Many people also appreciate the expansion of breeding techniques, as well. Thus, herbicide- risk to humans from exposure through the diet.” no-tillage agriculture which, in some crops, resistant weeds are not a problem with genetic It is worth pointing out that any concerns has been facilitated by using crop varieties engineering per se but with this particular ap- over glyphosate are not a problem with genetic genetically engineered to tolerate applications plication of genetic engineering. In any case, engineering per se but with this particular ap- of glyphosate. No-tillage means that crops are many (including the author) believe that en- plication of genetic engineering. Applications produced without physically disturbing the soil. gineered tolerance to glyphosate is not a sus- of genetic engineering must be evaluated on a This has benefits for the environment, including tainable, long-term approach to weed control. case-by-case basis. protecting the soil from erosion and reducing fuel usage. Also, many experts say that glypho- Only Roundup sate has less environmental impact than some Ready corn survived of the herbicides it has replaced in field crops. the application of While recognizing the above benefits, Roundup® herbicide there are also concerns with glyphosate- in the field shown in tolerant crops. Over the years, repeated use of this picture. glyphosate has caused the buildup of weeds Photo by Paul Vincelli resistant to this herbicide. Some herbicide manufacturers are now engineering plants to be tolerant to more than one herbicide. Glyphosate still controls many weeds, but

4 Farmers in Nicaragua who prefer traditional “landrace” varieties of corn to genetically engineered varieties Photo by Paul Vincelli Protecting Cultural Heritage. In Mexico 5 and Central America, resource-poor farm- ers often grow landraces of corn, which are corn varieties that may be centuries old. These traditional varieties may not produce top yields but they often perform adequately un- der a wide range of environmental conditions. This helps assure food security for their fami- lies. Landraces are also considered a cultural inheritance. Therefore, resource-poor farmers are often worried about genetically engi- neered crops pollinating with local landraces. In order to protect cultural heritage, it is very important that biotechnological in- Central American farmer with saved corn seed novations designed for developing countries Photo by Paul Vincelli be the product of teams that include local Patents Can Prohibit Seed Saving and Sharing. Resource-poor farmers may always share and biotechnologists as well as others that can 6 save non-patented seed. Some farmers appreciate the agronomic benefits offered by geneti- express local concerns (including local farm- cally engineered traits. Genetically engineered traits often are patented. Resource-poor farmers and ers and social scientists). indigenous peoples are not required to buy patented seed. However, if they do buy patented seed, patent laws may prohibit them from saving or sharing it, unless they pay a fee. Since many resource- poor farmers and indigenous peoples like to save and share seed, many prefer non-patented seed, whether it is genetically engineered or non-genetically engineered. its agronomic performance. How- ever, even in the USA, some dislike seed patents if they infringe on the santo, DuPont, and Syngenta) of the consolidation of the seed in- free and open saving and sharing of dominate the global seed market. dustry occurred decades before the seed. (But as noted above, our fed- The consolidation of an important first genetically engineered crops. eral laws do permit patents on seed sector of our food system in the Furthermore, large corporations do and on genetic traits). hands of a few transnational corpo- not own all genetically engineered ƒƒ Some are concerned about cor- rations creates concern for some. traits. Some are developed by public porate control of the food supply. This is an issue worthy of public research institutes and humanitar- Patents on genetically engineered discussion. However, this con- ian foundations. These organiza- crops have played a part in the solidation was not caused only by tions may choose to distribute their consolidation of the global seed the sale of genetically engineered genetically engineered traits freely. industry in recent decades. Three seed. Other factors were also Finally, patents on genetically transnational corporations (Mon- involved. In fact, the beginnings engineered traits do not last forever.

5 In the USA, they expire 20 years biodiversity in agroecosystems (some- reduce pesticide use, which helps after they are issued. Once a patent times called “domesticated diversity”). protect the ecosystems surrounding expires, the genetically engineered ƒƒ Biodiversity in non-agricultural farms. However, one can never rule trait is in the public domain. See 7: ecosystems (wild diversity). out the possibility of negative eco- Genetically Engineered Crops For All ƒƒ The destruction of tropical forests, logical effects from genetically en- Farms and All Farm Sizes. such as the Amazon region, results gineered crops, especially through `` Are food cultures affected by genet- in substantial loss of biodiversity. movement of engineered genes in ically engineered crops? Some peo- These deforested lands are some- pollen. It is important to minimize ple believe that the use of genetically times planted to monocultures of such risks. For this and other rea- engineered crops conflicts with their corn and soybeans, and these may sons, genetically engineered crops regional food culture, which may have be planted to genetically engineered are studied more than any other a foundation of centuries of history. varieties. While it would probably food in history. See 8: The Monarch Strong--and legitimate--objections to be impossible to find a scientist in Butterfly and Genetic Engineering. genetically engineered crops may be favor of tropical deforestation, de- ƒƒ Biodiversity in agroecosystems based on such a cultural belief. See 5: forestation is not caused by geneti- (domesticated diversity). Smallhold- Protecting Cultural Heritage. cally engineered crops but by other er farmers often grow traditional `` Does genetic engineering foster socioeconomic forces. crop varieties that harbor substan- monoculture farming? Large-scale ƒƒ Thus far, there are no reports of di- tial genetic diversity. The concern monoculture offers important ad- rect negative impact on biodiversity with genetically engineered crops vantages to farmers (and thus, to from genetically engineered crops is that they will displace traditional consumers), which is why it is so in ecosystems surrounding farm- varieties, resulting in erosion of common in diverse farming systems lands. In fact, the National Academy crop genetic diversity. This is a valid throughout the world. However, an of Sciences concluded, “Generally, concern, as this erosion of diversity important down-side of monoculture GE [genetically engineered] crops has certainly happened. However, is that it is potentially subject to de- have had fewer adverse effects on it is worth remembering that useful structive outbreaks of diseases and the environment than non-GE engineered genes can commonly be insect pests. To some extent, genetic crops produced conventionally.” moved (by conventional breeding) engineering can foster monocul- This is in part because certain into locally adapted varieties. This ture. Genetically engineered crops genetically engineered crops can provides the farmer with the advan- are often well-suited to farming tages of the genetically engineered systems of large-scale plantings of trait while still growing their locally a single, genetically uniform crop adapted varieties Thus, genetically species. However, monoculture is engineered crops do not necessarily not caused by genetically engineered cause a loss in local diversity of crop crops. Indeed, monoculture farming genetics. For each genetically engi- existed long before genetically engi- neered trait, it depends on how it is neered crops were first created, and used and on who owns the patent. monoculture is commonly practiced This is one reason why genetically today on non-genetically engineered engineered crops should always be crops throughout the world. Wheat evaluated on a case-by-case basis. in the USA is a good example. It is `` Do genetically engineered crops rarely grown in any way other than in Farmer in Bangladesh with eggplant genetically promote pesticide use? large-scale monoculture and yet it is engineered to resist insects ƒƒ Many emerging genetically engi- completely free of engineered genes. Photo courtesy of Mark Lynas neered traits have no impact on Furthermore, genetic engineering is Genetically Engineered Crops for All pesticide use. Certain genetically not just being used for crops grown 7 Farmers and All Farm Sizes. In the devel- engineered traits can actually by large-scale producers. Genetically oped world, genetically engineered crops are reduce pesticide use. See 9: Geneti- engineered traits in locally adapted commonly used on large-scale farms. However, cally Engineered Crops that Reduce varieties are also being used by small- in developing countries, genetically engineered Pesticide Use and 10: Plants that holder farmers in developing coun- crops are often used by smallholder farmers. Fight Back against Insects. More tries. See 7: Genetic Engineering Crops Smallholders who use genetically engineered such pesticide-reducing genetically For All Farms and Farm Sizes. traits often report higher crop productivity engineered traits are expected in ` ` Do genetically engineered crops and reduced pesticide use. In Colombia, female the future, especially for control of cause loss of biodiversity? There are farmers who grew genetically engineered cot- diseases and insects. two aspects to this issue: biodiversity ton appreciated not having to pay the cost of in non-agricultural ecosystems (some- insecticide application on their crop. times called “wild diversity”) and

6 Monarch butterfly Some crop production systems are dependent on pesticide applications. Genetic engineering is Photo courtesy of State Archives of Florida, Florida Memory, expected to continue to help reduce pesticide use. http://floridamemory.com/items/show/92059 Photo by Paul Vincelli The Monarch Butterfly and Genetic Genetically Engineered Crops that Reduce Pesticide Use. Some crops receive moderate to 8 Engineering. The Monarch butterfly 9 heavy pesticide use. Many research programs are developing genetically engineered traits that overwinters in Mexico. Populations of this make plants resistant to important diseases and insect pests. Such traits are being developed in pub- butterfly in known overwintering sites have lic laboratories as well as in commercial laboratories. In the author’s own scientific discipline—plant fallen dramatically in recent years. Some pathology—there are numerous, exciting genetic strategies which show great promise for safe, sus- scientists are concerned that the decline is tainable control of crop diseases with less dependence on pesticides. Many of these genetic traits actu- due to the widespread use of genetically en- ally come from crops already in the food supply. In other words, a potato variety can be made more dis- gineered crops with tolerance to the weed- ease-resistant by transferring one or more genes from another potato variety (or from a close relative). killer called glyphosate. The caterpillars of If we are transferring genes within a crop species, why not just use traditional breeding in- the Monarch butterfly depend on milkweed stead of genetic engineering? Indeed, sometimes traditional breeding are the best approaches to plants, where they feed. By sowing glypho- addressing particular challenges in crop improvement. However, sometimes genetic engineering sate-tolerant crops, producers can achieve offers the best approach. For example, moving desirable genes through genetic engineering can excellent weed control by spraying glypho- sometimes be faster than using traditional breeding techniques. Another advantage is that ge- sate on the field. This results in very low levels netically genetic engineering causes less genetic disruption to the original variety than traditional of weeds in cropland, including milkweed. breeding. A further advantage of genetic engineering is that resistance genes can be “stacked.” This It makes sense that excellent control means that several resistance genes can placed end-to-end in a genetic sequence and inserted of milkweed might be one of the reasons simultaneously, making it easier for the breeder to insert all of the beneficial genes. A breeder Monarch populations have suffered. Unfor- might do this to speed the breeding process. In addition, another reason for “stacking” genes is tunately, there is still considerable scientific to create crop varieties with durable resistance that could prove to be effective for many years. uncertainty about the reasons for the Mon- In addition to transferring genes within a crop species or its close relatives, a crop variety arch declines in known overwintering sites. may be made more disease-resistant by transferring a disease-resistance gene from another Furthermore, even if glyphosate plays a role, crop species. For example, a tomato variety can be made more disease-resistant by transfer- this is not a problem with genetic engineer- ring a gene from pepper. In most instances, such gene transfers between crop species might ing per se. It is simply the outcome of excel- not be possible without some form of genetic engineering. For some consumers, transferring lent weed control, something farmers like. genes into crops from plants already in the food chain may be more acceptable than transfer- If you care about Monarch butterflies, con- ring genes from evolutionarily distant organisms (like bacteria, for example). Some of these sider planting a Monarch Waystation, a gar- new traits are in the final stages of federal review and will likely be commercialized soon. A re- den to help them feed and reproduce (http:// search “pipeline” of other traits will undoubtedly lead to important new disease-resistance traits. monarchwatch.org/).

7 ƒƒ There are concerns that the use of of the world. These includes crops crops engineered to be tolerant to designed to alleviate deficiencies of herbicides can lead to increased Vitamin A, folate (a B vitamin espe- herbicide use over the long term. cially important for women of child- There is concern that this creates a bearing age), Vitamin C, iron, and “pesticide treadmill.” See 4: Crops other micronutrients and minerals. Tolerant to a Weed-Killer. There See 11: Golden Rice for the Health of also is concern that overuse of a sin- Children in Developing Countries. gle genetically engineered trait for ƒƒ Strange as it may seem, toxic sub- Corn at left with Bt trait which protects pest control may erode its effective- stances occur naturally in our foods. against fall armyworm damage; convention- ness over the long term, through This includes conventional foods, or- al corn at right showing significant damage the buildup of resistant pests. ganic foods, and any others.3 Many from fall armyworm ƒƒ These examples illustrate that each of these substances are produced Photo courtesy of Ricardo Bessin genetically engineered trait should naturally by plants as they grow. Plants that Fight Back against be evaluated on a case-by-case ba- Others are formed during food 10 Insects. Bt insecticidal proteins sis. Also, it is important to distin- preparation. Naturally occurring are natural products used for insect control. guish genetic engineering (which is toxins usually occur at low concen- (“Bt” stands for Bacillus thuringiensis, the a form of crop breeding) from risks trations in modern foods, but they bacterium that is the source of these insec- due to the pesticides that may be still cause some concern to nutri- ticidal proteins.) Bt proteins bind to the gut applied to engineered crops. tionists and other scientists. Certain of insects, eventually killing them. These genetically engineered crops can natural insecticides have a history of safe use Benefits of Genetic Engineering have considerably lower concentra- tions of naturally occurring toxins, by both conventional and organic farmers. `` Human health and nutrition. Certain genetically engineered crops have Genetically engineered crops can such as mycotoxins, which can have been engineered to produce one or more Bt improve human health and nutrition. serious health impacts. Other genet- proteins in the plant itself. Crops that produce Some examples: ically engineered crops will reduce Bt proteins need less insecticide than their ƒƒ Genetically engineered crops are our consumption of acrylamide, conventional counterparts. This has many classified as a probable human being developed to alleviate food 4 benefits, including less pesticide in the envi- allergies. For example, people who carcinogen. Thus, genetically engi- ronment, greater survival of beneficial insects suffer from celiac disease cannot neered crops can help us reduce our in farmlands, and less pesticide in our diets. tolerate gluten, which are certain dietary exposure to natural toxins. Bt proteins are powerful for controlling proteins found in wheat. Celiac See 3: Improving Food Safety through certain insects, but the good news is that they sufferers must follow a strict diet Genetic Engineering. have extremely low toxicity to humans. In fact, free of wheat flour. However, ƒƒ Genetically engineered crops are they are actually less toxic to humans than promising research is creating being developed to provide sus- common table salt. To pose a risk, a person genetically engineered wheat with tainable sources rich in certain would have to eat tens of thousands of pounds greatly reduced gluten content. If health-promoting omega-3 fatty of Bt corn in one day, which is physically im- successful, genetically engineered acids for use as fish feed in aqua- possible. Bt corn can actually be safer for wheat may allow those suffering culture. Presently, fish and seafood people and livestock than conventional corn celiac disease to enjoy bread, pasta, from the oceans are the predomi- because it sometimes has lower levels of nat- pizza, and other products normally nant source of these fatty acids for ural toxins called mycotoxins. See 9: Improv- made with wheat flour. Other re- human diets, but the oceans are ing Food Safety through Genetic Engineering. searchers are working to develop being overfished. See12: Creating One concern about crops engineered to hypoallergenic peanuts. Sustainable Sources of Health-Pro- produce Bt proteins is that they will foster the ƒƒ Some genetically engineered crops moting Fish Oils. development of insect resistance to pesticides under development are designed to ƒƒ Genetically engineered crops can that use live Bacillus thuringiensis or Bt- alleviate serious nutrient deficien- be developed to have high amounts derived proteins. For example, in many loca- cies in humans, especially in the of healthy oils. For example, a tions, the western corn rootworm is resistant developing world. There are several variety of soybean has been engi- to certain Bt-derived proteins. This reduces genetically engineered crops under neered to produce high amounts the effectiveness of Bt-based pesticides avail- development which are expected to of a healthy oil called oleic acid. able to organic growers, as well as conven- improve the nutrition of children, Other crops with greater amounts tional growers. Farmers often use practices women, and men in many parts of healthy oils are expected. to reduce the risk of insect resistance to Bt toxins, but the widespread use of engineered 3 See, for example, the well-known paper by Dr. Bruce N. Ames et al. (1990) at http://www.pnas.org/content/87/19/7777. crops expressing Bt proteins does present abstract. risks for the development of insect resistance. 4 See http://www.cancer.gov/about-cancer/causes-prevention/risk/diet/acrylamide-fact-sheet.

8 Normal rice at left, Golden Rice at right Photo from the Golden Rice Humanitarian Board, http://www.golden- rice.org/Content4-Info/info1_photos.php Golden Rice for the Health of Chil- 11 dren in Developing Countries. Crops enriched with important vitamins, micronutri- ents and minerals may help reduce malnutrition in the developing world. Millions of pre-school children are affected by Vitamin A deficiency. Ideally, all children would obtain sufficient -Vi tamin A through a diversified diet, and nutrition programs are making headway against Vitamin A deficiency. Unfortunately, in some regions of the world, many impoverished or even land- less families are presently unable to provide adequate dietary Vitamin A to their children. Part of the solution to this problem may be Golden Rice. Golden Rice (Generaltion 2) is rice with three genes added: two from plants and one from a bacterium. These three genes al- low rice to make beta-carotene (also called provitamin A), giving the grains a golden color. Beta-carotene is the same natural substance that makes carrots orange. When people consume Seedheads and seeds of genetically Golden Rice, the beta-carotene is naturally con- engineered Camelina sp., a source verted to Vitamin A. Presently, one challenge is of important omega-3 fatty acids to create Golden Rice varieties that produce rice Photo courtesy of Rothamsted Research yields at least as good as prevailing rice varieties. Scientists are working to address this challenge. Creating Sustainable Sources Golden Rice is not the only genetically en- 12 of Health-Promoting Fish gineered approach to alleviating nutrient defi- Oils. Omega-3 fatty acids are important ciencies. Corn enriched for multiple important in the human diet, because our body cannot make them; we must obtain them from food. nutrients has also been developed by genetic They also help to promote health. We humans obtain some of the most important omega-3 engineering. Sometimes conventional breeding is fatty acids1 from fish caught in the oceans. Unfortunately, the oceans are being overfished, successful in increasing nutrition content of certain so this is an unsustainable source of these health-promoting fatty acids. Even aquaculture crops. Nutrition-enhanced crop varieties are badly (fish-farming) is unable to provide what we need, since fish in aquaculture systems also get needed, whether they are developed through their health-promoting fatty acids from fish obtained from the oceans. Genetically engineered conventional breeding or genetic engineering. plants are being developed to provide a novel source of omega-3 long-chain polyunsaturated Nutrition-enhanced crops varieties will not ad- fatty acids for use in fish feeds, potentially helping to make aquaculture more sustainable. dress issues of poverty or social justice. However, if developed with respect for local populations, local cultures, and sustainable economies, they could 1 contribute to improved quality of life for some of The omega-3 (n-3) long-chain polyunsaturated fatty acids, particularly those abbreviated EPA and DHA. These are not found in plant-based sources of omega-3 fatty acids. the poorest among us.

9 ƒƒ Genetically engineered tomatoes to consumers (less pesticide resi- ƒƒ Soil conservation. In some crops, with deep purple color may have dues on foods) and the environment use of certain genetically engineered significant health benefit. See13: (less contamination of ecosystems). varieties can facilitate the expan- Purple Tomatoes That May Help Furthermore, significant benefits for sion of no-tillage agriculture. This Fight Cancer. farmers and farm workers include protects the land from erosion and ƒƒ Less pesticide. Studies commonly less exposure to pesticides and helps promote healthy soils. No- have shown reductions in pesticide fewer pesticide poisonings. This tillage farming may also increase use through the use of certain is true even on smallholder farms. natural carbon storage in soils. This genetically engineered crops, such More such pesticide-reducing helps to mitigate climate change. as those engineered to produce Bt genetically engineered crops are Finally, no-till farming helps protect protein. (See 10: Plants that Fight expected in the future. Numerous rivers, lakes, and streams, by reduc- Back Against Insects and 9: Geneti- public and private research projects ing runoff of nutrients and soil that cally Engineered Crops that Reduce throughout the world are working pollute surface waters. See 4: Crops Pesticide Use). This is true in both to use genetics (including genetic Tolerant to a Weed Killer. developed countries and developing engineering) instead of pesticides in ƒƒ Increased yield. Numerous stud- countries, including on smallholder order to control crop diseases and ies have found yield increases as- farms. This has important benefits insect pests. sociated with the use of genetically ƒƒ Environmentally friendly pest engineered crops. Yield increases control. Certain genetically en- from the current generation of gineered crops are designed to be genetically engineered crops have resistant to damaging insects and usually been due to improved diseases. This can help increase insect and weed control. Future yield as well as reduce pesticide genetically engineered crops may use, as mentioned above. Some ge- produce higher yields via other netically engineered crops promote mechanisms, possibly including the buildup of natural enemies more efficient photosynthesis. of destructive insect pests. This Conventional breeding also pro- is because these crops need less duces yield increases, so you can insecticide use. Less insecticide expect crop improvement to ben- use protects the natural enemies. efit from conventional techniques See 10: Plants that Fight Back and from genetic engineering. Genetically engineered purple tomatoes against Insects, 14: Restoring the Producing high yields of food and with potential cancer-protective health Once-Mighty American Chestnut, fiber on cropped land is beneficial benefits 15: Virus-Resistant Papaya Saves because it preserves other land Photo courtesy of Cathie Martin, John Innes Centre an Industry, and 16: Saving Florida for wildlife habitat and watershed protection. Purple Tomatoes May Help Fight Oranges. 13 Cancer. Both red and purple to- ƒƒ Lower environmental footprint. ƒƒ Reduced labor costs. Genetically matoes have natural plant pigments called Most scientists believe that present engineered crops that allow for anthocyanins, but the purple ones shown and future genetically engineered pesticide reductions often mean here have substantially more. The high- crops can help reduce the environ- that labor costs are reduced. As an anthocyanin tomatoes in this photo are due mental footprint of our food system. example, women who farm geneti- to the insertion of two genes from snap- Examples include: 12: Creating cally engineered cotton in Colom- dragon. Using laboratory mice with a strong Sustainable Sources of Health-Pro- bia appreciate how they no longer tendency to develop cancer, the researchers moting Fish Oils, 10: Plants that Fight have to pay someone to spray their found that consuming these purple toma- Back against Insects, and 17: Fertiliz- crop with insecticides. Reduced toes extended the lives of the mice by 30%. er from Thin Air. In addition to these labor costs are beneficial for the Juice from these purple tomatoes may help examples, genetically engineered farmer and ultimately for the reduce cancer risk, once it is commercial- crops currently under development consumer (because of lower food ized. Certain heirloom varieties of tomatoes are expected to use fertilizer and prices). However, it is important to are also deep purple color and may offer the irrigation more efficiently, reduc- note that reduced labor needs may same health benefits, although they have not ing the impact of farming on water affect local employment, which been similarly tested for such benefits. Fur- quality and water supply. Others can be a negative consequence of thermore, the genetically engineered genes are expected to reduce emissions improved farming efficiency. potentially may be more easily moved into of greenhouse gases. Still others other tomato varieties adapted to other re- are expected to reduce food waste, gions than the genes in the heirloom varieties. which will have important environ- mental benefits.

10 Restoring the Once-Mighty American 14 Chestnut. The American chestnut was one of the most common and valued trees in North American forests. It has been nearly wiped out by a non-native, invasive fungal disease, called chestnut blight. For over a century, conventional disease-control approaches have failed to undo the ecological damage caused by chestnut blight. However, researchers have made a significant advance that may help in the restoration of this classic American tree. A single gene from wheat, transferred into American chestnut, makes it resis- tant to the damage caused by the chestnut blight fungus. Presently, this genetically engineered American chestnut is undergoing federal review.

Fallen chestnut tree Photo by Andrej Kunca, National Forest Centre—Slovakia, Bugwood.org

Virus-Resistant Papaya Saves an 15 Industry. In the 1990s, a naturally occurring virus called papaya ringspot virus was destroying the papaya industry in Hawaii. Researchers at Cornell University developed two genetically engineered papaya varieties which contain a small fragment of the genetic sequence of the virus. This fragment triggers natural disease resistance in the papaya. Eat- ing this genetic fragment poses no known health risks. In fact, when consumers eat non- engineered papaya, they often are eating the Non-engineered papaya (at left) and papaya Papaya fields in 1994, severely affected by papaya entire virus, not simply a small fragment of engineered to resist the virus. ring spot virus. These fields were abandoned its genetics. Virus-resistant papaya was com- because of the disease damage. mercialized in 1998, and it has helped to save the papaya industry in Hawaii. Many more ex- amples of disease-resistant genetically engi- neered crops are under development. These are expected to reduce loss from diseases, as well as reduce the use of disease-control chemicals.

Aerial view of field trial begun in 1995, showing a solid block of virus-resistant papaya growing well while the sur- rounding susceptible papaya is severely damaged by the virus. Photo taken 19 months after start of the field trial.

Photos reproduced, with permission, from: • Gonsalves, D., Gonsalves, C., Ferreira, S., Pitz, K., Fitch, M., Manshardt, R., and Slightom, J. 2004. Transgenic virus-resistant papaya: From hope to reality in controlling Papaya ringspot virus in Hawaii. APSnet Features. Online. DOI: 10.1094/APSnetFeature-2004-0704. • Gonsalves, D., Tripathi, S., Carr, J. B., and Suzuki, J. Y. 2010. Papaya ringspot virus. The Plant Health Instructor. DOI: 10.1094/PHI-I-2010-1004-01.

11 ƒƒ Higher profits. Many times, farm- ers’ profits are higher with geneti- cally engineered crops. This has been documented in developing countries as well as developed countries. In developed countries, this helps support farmers, the peo- ple that grow our food. In develop- ing countries, higher profits mean greater food security and a better quality of life for farm families. ƒƒ Stress-tolerant crops. In order to feed us, farmers must produce crops under the environmental stresses of a changing climate. Genetically en- gineered traits are being developed to protect against those stresses, in- cluding crop tolerance to flooding, drought, and temperature extremes. Genetic engineering is most suc- cessful when a trait depends on one or a few genes. Sometimes, crop tol- Citrus tree exhibiting citrus greening erance to stresses is due to complex Photo by H.D. Catling, Bugwood.org genetics. In such cases, conventional Saving Florida Oranges. Citrus greening is a highly destructive disease that invaded Florida breeding is sometimes more effec- 16 in 2005. Since its detection, 135,000 acres of Florida citrus production have been abandoned tive than genetically engineered due to citrus greening, and there is concern that the state eventually will lose most of its citrus pro- technologies. However, there are duction. So far, conventional disease-control techniques, including breeding, have performed poorly. cases where genetically engineered Orange producers are applying substantial amounts of insecticide in a desperate attempt to slow can be highly effective in increasing disease development, but this has provided poor results. Recently, through genetic engineering, a stress tolerance. See 18: Rice Toler- single gene from spinach was inserted into an orange plant. This orange variety has exhibited a high ant to Drowning, for an example. level of resistance to citrus greening. It is currently undergoing federal review. Citrus greening has also been detected in other citrus-producing states in the USA.

Fertilizer from Thin Air. Deficiencies 17 of nitrogen can affect crop growth, as is evident in this photo. In cereals like corn, rice, and wheat, nitrogen is typically supplied by applying fertilizer to the soil. This practice helps farmers attain high yields. Unfortunately, fertilizer ap- plications to the soil can result in contamination of rivers, lakes, and groundwater with nitrogen. Furthermore, the manufacture and use of nitro- gen fertilizers can contribute to global warming. One of the most exciting areas of genetic engi- neering research are studies working on transfer- ring genes into cereal crops so they can capture nitrogen out of the air. If this research is successful, this will be an advance of incalculable value to hu- manity. Cereal farmers throughout the world will no longer need to purchase nitrogen fertilizer, and Corn at right shows symptoms of nitrogen deficiency. pollution caused by the manufacture and use of Photo courtesy of Dr. Andrew Leakey, University of Illinois nitrogen fertilizer will be greatly reduced.

12 Engineering with Genes from 19 Close Relatives. Genetic engineer- ing sometimes involves the transfer of genes among organisms which are completely unrelated to one another. For example, a gene from a bacterium can be inserted into a plant’s genetics. This process is called transgenesis, and a transferred gene is call a transgene. It is interesting to con- template the fact that bacterial genes can function when inserted into our crop plants. They work because the genetic code of life on Earth is essentially universal. Thus, genes from one organism will often function quite well when transferred in another organism. While transgenes commonly do function in the plant that receives them, some consum- Conventional rice at left, which was killed by submersion for several weeks; engineered rice at right, ers are uncomfortable with crossing species tolerant of the “drowning” conditions that killed the conventional plant boundaries through laboratory manipulation. Photo courtesy of Pamela Ronald They are more comfortable with cisgenesis. Cisgenesis is the engineering of crops Rice Tolerant to Drowning. Insertion of a single gene from an ancient rice variety into a using only genetics from the crop’s breed- 18 modern rice variety allows this genetically engineered rice to tolerate as much as nearly three ing pool. For example, a cisgenic potato may weeks of submersion under water. This new genetically engineered trait is now being used on millions have a gene inserted by genetic engineering, of farms. This is important because each year, submergence causes the loss of enough rice to feed but that gene (and all others) must come over 30 million people. Sometimes crop tolerance to environmental stress is due to complex genetics, from either cultivated potato or from wild which would make genetic engineering less effective than other breeding techniques. However, this potato. These are both within the breed- is a case where a single gene, transferred by genetic engineering, was very effective. ing pool of potato. Cisgenic crops can thus take advantage of genetically engineered laboratory techniques. However, because the genetic engineer is only using genes Reviewers Selected References from the natural breeding pool of potato, Reviewers of previous drafts of this Below are a few examples of the very cisgenic changes could, in principle, arise publication include Jannine Baker, extensive collection of peer-reviewed through traditional breeding techniques. Ricardo Bessin, Lynn Blankenship, Den- scientific articles that are the founda- This makes them more acceptable to some nis Duross, Michael Goodin, Krista Ja- tion of this University of Kentucky consumers who may oppose transgenesis. cobsen, Lee Meyer, Janet Mullins, Robert Extension fact sheet, Genetically Engi- You might wonder, if cisgenic varieties Perry, Keiko Tanaka, and Mark Williams, neered Crops: Emerging Opportuni- could be produced by traditional breeding, of the University of Kentucky; Rebecca ties. Italicized comments are provided why even bother with genetic engineering? Harrison, of the Cornell Alliance for for each citation. Most of these articles One answer is because, for some crops, using Science; Maria Mercedes Roca, of Tech- are freely available to the general conventional breeding techniques may take nológico de Monterrey; and David Tribe, public. A few require payment for ac- years to decades to achieve what might be of the University of Melbourne. cess, although a summary is publically possible in the laboratory in as little as one available. Although we regret the cost year or less. Using genetic engineering would Disclosure for those that require payment, they are be a way to “fast-track” important genes, The author declares no conflicts of included because they form an impor- while still staying within the crop’s natural interest (past or present) with respect to tant part of the scientific literature and breeding pool. Furthermore, sometimes tra- genetic engineering. Interested readers may be of interest to readers. ditional breeding is limited because of link- can find a completed conflict-of-interest `` Carrière and others, 2015. Optimiz- age drag. This is a technical term that basi- form in the file namedcoi_disclosure_ ing pyramided transgenic Bt crops cally means that some of the best qualities of GE_crops_Paul_Vincelli, at https://www. for sustainable pest management. an elite crop variety may be lost as a result of dropbox.com/sh/ys0gsvqrn03cvld/ Nature Biotechnology doi:10.1038/ the breeding process. Genetic engineering is AADephoD0TvKxqcJ_l18vO_ka?dl=0. nbt.3099. http://www.nature.com/nbt/ a way to introduce important genetic traits In addition, please see the disclosure journal/v33/n2/full/nbt.3099.html. An quickly and without linkage drag. statement at http://out-of-the-box-vin- example of the ways scientists work to re- celli.blogspot.com/2015/11/disclosure- duce the buildup of resistant pests when statement-on-industry.html using biotech traits on large acreages.

13 `` Davis and Dyer, 2015. Long-Term `` Kouser and Qaim, 2011. Impact of accessed 3 Jul 2015. A scientific review Trends in Eastern North American Bt cotton on pesticide poisoning in of long-term feeding studies for GE Monarch Butterflies: Collection smallholder agriculture: A panel crops. of Studies Focusing on Spring, data analysis. Ecological Econom- `` Lu and others, 2015. Widespread Summer, and Fall Dynamics. An- ics Vol. 70, pages 2105–2113. http:// adoption of Bt cotton and insecti- nals of the Entomological Society of www.sciencedirect.com/science/arti- cide decrease promotes biocontrol America, pages 1–3; DOI: 10.1093/ cle/pii/S0921800911002400, accessed services. Nature Vol. 487, pages 362- aesa/sav070. http://aesa.oxfordjourn- 3 Jul 2015. This research reports re- 366. http://www.nature.com/nature/ als.org/content/early/2015/08/03/ duced pesticide poisonings where a GE journal/v487/n7407/full/nature11153. aesa.sav070. An introduction to the crop was used, one that was designed html, accessed 3 Jul 2015. Research latest science revealing the complex- to reduce pesticide use. reporting positive environmental ben- ity involved in the efforts to determine `` Kyndt and others, 2015. The ge- efits from the use of GE cotton. why Monarch populations have fallen nome of cultivated sweet potato `` US-Food and Drug Administration. drastically in Mexico. contains Agrobacterium T-DNAs 2015. Questions & answers on food `` Duke, 2015. Perspectives on trans- with expressed genes: An example from genetically engineered plants. genic, herbicide-resistant crops in of a naturally transgenic food http://www.fda.gov/Food/Food- the United States almost 20 years crop. Proceedings of the National ScienceResearch/Biotechnology/ after introduction. Pest Manage- Academy of Sciences /doi/10.1073/ ucm346030.htm, accessed 3 Jul 2015. ment Science Vol. 71, pages 652-657. pnas.1419685112. http://www.pnas. An overview by the US-FDA on geneti- http://onlinelibrary.wiley.com/ org/content/112/18/5844, accessed cally engineered crops. FDA evaluates doi/10.1002/ps.3863/abstract, ac- 3 Jul 2015. A recent example of the GE crops for food safety. cessed 3 Jul 2015. A scientific review of discovery of genetic material that ap- `` Vincelli, 2013. GMOs and corn my- GE-based crop tolerance to herbicides, pears to have moved across species cotoxins. Kentucky Pest News http:// including the challenges of resistance and genus boundaries. Many other graincrops.blogspot.com/2013/08/ in weeds to herbicides. such studies are available. These stud- gmos-and-corn-mycotoxins.html, ac- `` Fernandez-Cornejo and others, 2014. ies suggest that similar laboratory cessed 3 Jul 2015. A short overview of Genetically Engineered Crops in manipulations by human are not at how certain GE traits have improved the United States. USDA Economic all unnatural. food safety for corn. Research Report No. ERR-162. http:// `` Ladics and others, 2015. Genetic `` Vincelli, P. 2015. Consumption of www.ers.usda.gov/publications/err- basis and detection of unintended Genetically Engineered (=GMO) economic-research-report/err162. effects in genetically modified crop Crops: Examples of Quotes from aspx, accessed 3 Jul 2015. This report plants. Transgenic Research DOI Position Papers of Scientific Or- from the US Department of Agricul- 10.1007/s11248-015-9867-7. http:// ganizations. Kentucky Pest News, ture presents information on GE crops link.springer.com/article/10.1007% https://kentuckypestnews.wordpress. used in the USA and their impacts. 2Fs11248-015-9867-7, accessed 3 Jul com/2015/03/31/consumption-of- `` Gressel, 2014. Dealing with trans- 2015. Presents current scientific find- genetically-engineered-gmo-crops- gene flow of crop protection traits ings on many aspects of GE crops, es- examples-of-quotes-from-position- from crops to their relatives. Pest pecially in relation to other techniques papers-of-scientific-organizations/, Management Science DOI 10.1002/ of crop improvement. accessed 3 Jul 2015. This article pro- ps.3850. http://onlinelibrary.wiley. `` Nicolia and others, 2013. An overview vides a list of quotes from many pres- com/doi/10.1002/ps.3850/abstract, of the last 10 years of genetically en- tigious scientific organizations about accessed 3 Jul 2015. A scientific review gineered crop safety research. Criti- the safety of consuming GE crops. of the concern that genetic material cal Reviews in Biotechnology. DOI: `` Yang and others, 2014. Engineer- from GE crops may transfer to wild 10.3109/07388551.2013.823595. http:// ing anthocyanin biosynthesis in relatives. The review also discusses informahealthcare.com/doi/abs/10.3 plants. Current Opinion in Plant ways such risk might be reduced. 109/07388551.2013.823595, accessed Biology. Vol. 19, pages 81-90. http:// `` Klumper and Qaim, 2014. A meta- 3 Jul 2015. 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