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University of Kentucky College of , & Environment Extension Pathology

College of Agriculture, Food and Environment Cooperative Extension Service

Plant Pathology Fact Sheet PPFS-MISC-07 Genetically Engineered — A Review of Concerns and Benefits1 Paul Vincelli Extension Plant Pathologist

As the global population increases, there is an ever- in the USA since 1996. Most genetically engineered greater need for increases in yields on the same crops are not consumed directly by humans, but amount of land. In addition, an increased focus rather are used for animal feed, processing, or for on , , reduced agricultural fuel production. Although there are no new inputs, and reduction of , puts further from consuming GMO crops, those that wish to avoid pressure on crops and growers. Thus, some have all derived from can buy turned to genetically engineered crops as a way to certified organic foods or those specifically labelled meet the demands of a changing world. to be GMO-free.

The genetic modification of is nothing new, as The manipulation of the genetic make-up of crops nature genetically modifies in bizarre and raises numerous concerns and questions for many remarkable ways through natural changes over time consumers. Should these products be regulated? (Example 1). Humans have guided genetic changes Are they safe? What are the benefits of GMOs? The in crops for thousands of years through simple following aims to provide an unbiased review of the selection. Conventional is based concerns and benefits of genetically engineered on the selection of individual plants with desirable crops based on the research available on the topic. traits and transfer of these traits into a population. Conventional breeding techniques produce changes Example 1— to the crop’s DNA, but usually with less precision Sweetpotato: than genetic engineering. However, conventional Genetically Engineered breeding techniques are still very useful. by Nature

Genetically engineered crops are plants that have Transfer of genes from one to another had their genetic material (DNA) purposefully seems bizarre, but this manipulated in the laboratory to produce a happens regularly in particular beneficial outcome. These types of crops natural . It are often called genetically modified organisms, or is one way that nature GMOs. Commercial genetically engineered crops are creates . Sweetpotato, an example of designed to have limited and precise genetic changes Scientists have recently a natural GMO. that provide one or more benefits to humans or the reported that sweet environment. -potato naturally contains at least four genes from a - dwelling bacterium. Examples of natural gene transfer Genetic engineering has been part of American life for are common in the scientific literature, and more are being discovered regularly as science advances. decades. Genetically engineered corn has been grown 1 Summarized from the UK publication Genetically Engineered Crops: Emerging Opportunities (PPA-47) by Kimberly Leonberger, Extension Associate Agriculture & Natural Resources • Family & Consumer Sciences • 4-H/Youth Development • Community & Economic Development Concerns Expressed About varieties of corn grown by smallholders in . Although there is still some scientific uncertainty that Genetic Engineering this has happened, many scientists are concerned Is genetic engineering natural? about the possibility. There is evidence of Nature commonly and naturally produces dramatic spread into a canola field in intended for changes in the of plants. In making dramatic , which resulted in unpleasant changes in DNA, nature creates biodiversity. litigation. Instances like these highlight a significant Laboratory techniques of genetic engineering were challenge for the use of those genetically engineered developed by studying the creative things nature traits that may spread in . does with DNA.

Are genetically engineered crops safe to eat? Example 2—Improving � Genetically engineered crops grown in the Food Safety through USA are subjected to detailed scrutiny for safety to Genetic Engineering humans and the environment. The U.S. Department In some cases, of Agriculture, the U.S. Food and Drug Administration, engineered crops can be and the U.S. Environmental Protection Agency safer than conventional evaluate the safety of genetically engineered crops. In foods. Corn grain can be contrast, non-engineered (non-GMO) crop varieties naturally contaminated by , which typically receive very little to no formal evaluation by are produced by government agencies. fungi. Mycotoxins pose � Many scientific experts worldwide agree that health risks to genetically engineering a crop generally presents and humans. Several no new health risks that cannot also arise from types of livestock are Fungal growth of Fusarium conventional plant breeding. subject to by ear and kernel rot of corn � mycotoxins, which can that can result in contami- Certain genetically engineered traits can actually nation by mycotoxins. improve the safety of food (Example 2). result in death. Human � There is ongoing scientific discussion over crops exposure to these engineered to be tolerant to the -killer called compounds has been linked to specific birth defects, esophageal cancer, and liver damage. . Numerous studies show no significant health risk to humans from government-approved One way corn growers can reduce the level of uses of glyphosate. However, some experts do raise contamination is through the use of varieties with a Bt questions about the safety of long-term exposure to trait. The fungi that result in mycotoxins often invade glyphosate in the diet. This is one reason some want grain through wounds, such as those that result from feeding. Bt traits can reduce insect feeding and products derived from genetically engineered crops limit wounds that could be colonized by mycotoxin- to be labeled. producing fungi.

Can genetic material from genetically Do patents on seeds or genetic traits cause engineered crops spread in pollen? concern? � Genetically engineered genes may move into � The majority of acreage planted to genetically wild relatives of crops plants when pollen from the engineered crops in the USA is/was patented by genetically engineered crop lands on the of multinational corporations. Federal laws allow for a wild relative. Genes that are foreign to native plant such patents to help protect the investment of those species may be introduced through the pollen. Such that develop new genetic . may gene spread could negatively impact biodiversity not save seed from a patented genetically engineered in some instances. No such cases have been crop. documented to date. � The cost of legally using a patented genetically � Genetically engineered genes may move into engineered trait can increase the cost of crop fields of producers growing crops intended to be production. In developing countries, resource-poor free of genetically engineered genes. There is some farmers and indigenous peoples often prefer seed evidence that this has happened in traditional that is not genetically engineered. However, in developed nations, many farmers choose to pay for use, which helps protect the ecosystems surrounding the genetically engineered seed because they value . However, one can never rule out the possibility its agronomic performance. of negative ecological effects from genetically � Some are concerned about corporate control of engineered crops, especially through movement of the food supply. Patents on genetically engineered engineered genes in pollen. crops have played a part in the consolidation of the global seed industry in recent decades. The Biodiversity in agroecosystems (=domesticated beginnings of the consolidation of the seed industry diversity). The concern with genetically engineered occurred decades before the first genetically crops is that they will displace traditional varieties, engineered crops. Furthermore, large corporations resulting in erosion of crop . However, do not own all genetically engineered traits. Some useful genetically engineered genes can commonly are developed by public research institutes and be moved (by conventional breeding) into locally humanitarian foundations. Patents on genetically adapted varieties. Thus, genetically engineered crops engineered traits do not last forever. Once a patent do not necessarily cause a loss in local diversity of expires, the genetically engineered trait is in the crop genetics. public domain. Do genetically engineered crops promote Are food cultures affected by genetically use? engineered crops? � Many emerging genetically engineered Some people believe that the use of genetically traits have no impact on pesticide use. Certain engineered crops conflicts with their regional food genetically engineered traits can reduce pesticide culture, which may have a foundation in centuries of use (Examples 3 & 4). More pesticide-reducing history. Example 3—Genetically Engineered Crops that Does genetic engineering foster Reduce Pesticide Use farming? Many research programs are developing genetically Large-scale monoculture offers important engineered traits that make plants resistant to advantages to farmers and consumers. To some important diseases and insect pests. With an increased extent, genetic engineering can foster monoculture. tolerance to diseases and pests comes a reduction in However, monoculture is not caused by genetically pesticide use. Many of these genetic traits come from engineered crops. Indeed, monoculture farming crops already in the food supply, meaning a new variety existed long before genetically engineered crops can be made more disease-resistant by transferring one or more genes from another variety, or from a were first created, and monoculture is commonly close relative. For other genetically engineered crops, practiced today on non-genetically engineered crops resistance genes may come from other crop species throughout the world. An important down-side of or organisms. While it might be possible to produce monoculture is it’s potentially subject to destructive the same outcome with traditional breeding, genetic outbreaks of diseases and insect pests. engineering can often produce these new varieties faster, result in less genetic disruption to the original Do genetically engineered crops cause loss of variety. Genetic engineering also can provide the ability biodiversity? to insert multiple beneficial genes at once (“stacking”), which could result in a more durable resistance. Biodiversity in non-agricultural ecosystems (=wild diversity). To date, there are no reports of direct Some crop negative impact on biodiversity from genetically production systems engineered crops in ecosystems surrounding are dependent on pesticide farmlands. The National Academy of Sciences applications. concluded, “Generally, GE (genetically engineered) Genetic crops have had fewer adverse effects on the engineering environment than non-GE crops produced is expected to conventionally.” This is in part because certain continue to help reduce pesticide genetically engineered crops can reduce pesticide use. � Some genetically engineered crops under Example 4—Plants that development are designed to alleviate serious Fight Back Against nutrient deficiencies in humans, especially in the The bacterium, Bacillus developing world. There are several genetically thuringiensis, which is engineered crops designed to alleviate deficiencies often abbreviated Bt, of Vitamin A, folate, Vitamin C, iron, and other produces insecticidal micronutrients and minerals. proteins that can be used � Toxic substances occur naturally in our foods, for insect control. Bt whether conventional or organic. Many of these proteins bind to the gut of insects, eventually killing substances are produced naturally by plants as they them. Certain genetically grow. Others are formed during food preparation. engineered crops produce Corn at left with Bt trait, Certain genetically engineered crops can have one or more Bt proteins which protects against considerably lower concentrations of naturally in the plant. These crops fall armyworm damage. occurring toxins, such as mycotoxins, which can have Conventional corn at need less right showing significant serious health impacts. than conventional damage from fall � Genetically engineered crops can be developed counterparts, resulting armyworm. to have high amounts of healthy oils. For example, a in less pesticides in the variety of soybean has been engineered to produce environment, greater survival of beneficial insects, and high amounts of a healthy oil called oleic acid. less pesticide in our diets. Bt proteins pose an extremely low risk to humans, as they are less toxic than common table . Less pesticide Studies have shown reductions in pesticide use One concern about Bt crops is the possibility of through the use of certain genetically engineered insect resistance to pesticides that use live Bacillus crops, such as those engineered to produce Bt thuringiensis or Bt-derived proteins. Farmers often protein. This has important benefits to consumers use practices to reduce the risk of insect resistance (less pesticide residues on foods) and the to Bt toxins, but the widespread use of Bt engineered environment (less contamination of ecosystems). crops does present risks for the development of insect Significant benefits for farmers and workers resistance. include less exposure to pesticides and fewer genetically engineered traits are expected in the pesticide . future, especially for control of diseases and insects. � There are concerns that the use of Environmentally friendly control tolerant crops can to increased herbicide Certain genetically engineered crops are designed use over the long term. There also is concern that to be resistant to damaging insects and diseases overuse of a single genetically engineered trait for (Examples 5 & 6). This can help increase yield as may erode its effectiveness over time, as reduce pesticide use. Some genetically engineered through the buildup of resistant pests. crops, which require few , promote the � It is important to distinguish genetic engineering buildup of natural enemies of destructive insect (which is a form of crop breeding) from risks due to pests. the pesticides that may be applied to engineered crops. Lower environmental footprint Most scientists believe that present and future Benefits of Genetic Engineering genetically engineered crops can help reduce the environmental footprint of our food system. Human health and nutrition Genetically engineered crops currently under � Genetically engineered crops are being development are expected to use and developed to alleviate food allergies. For example, irrigation more efficiently, reducing the impact of research is creating genetically engineered farming on and water supplies. Others with greatly reduced gluten content. If successful, are expected to reduce emissions of genetically engineered wheat may allow those gases. Still others are expected to reduce food waste, suffering celiac disease to enjoy foods normally which will have important environmental benefits. made with wheat flour. Example 5—Restoring Example 6—Saving the Once-Mighty Florida Oranges American Chestnut Citrus greening is a The American chestnut highly destructive was one of the disease that invaded most common and Florida in 2005. Since valued trees in North its detection, 135,000 American forests before Fallen chestnut tree. acres of Florida citrus it was nearly wiped out production have Citrus tree exhibiting citrus by a non-native, invasive fungal disease, called chestnut been abandoned due greening. blight. For over a century, conventional disease-control to citrus greening, approaches have failed to undo the damage caused and there is concern that the state eventually will lose by chestnut blight. However, researchers have made a most of its citrus production. To date, conventional significant advance that may help in American chestnut disease-control techniques, including breeding, restoration. A single gene from wheat, transferred have performed poorly. Recently, a single gene from into American chestnut, makes it highly resistant to spinach was inserted into an orange plant and the the damage caused by the chestnut blight . new variety has exhibited a high level of resistance to Presently, this genetically engineered American citrus greening. The new orange variety is currently chestnut is undergoing federal review. undergoing federal review. Soil conservation Higher profits Use of certain genetically engineered varieties can Many times, farmers’ profits are higher with facilitate the expansion of no-tillage agriculture genetically engineered crops. In developed countries, in some crops. This protects the land from erosion this helps support farmers, while in developing and helps promote healthy . No-tillage farming countries, higher profits mean greater may also increase natural carbon storage in soils, and a better quality of life for farm families. which helps to mitigate climate change. Finally, no- till farming helps protect rivers, lakes, and streams, Stress-tolerant crops by reducing runoff of nutrients and soil that pollute Farmers must produce crops under the environmental surface waters. stresses of a changing climate. Genetically engineered traits are being developed to protect against those Increased yield stresses, including crop tolerance to flooding, Numerous studies have found yield increases drought, and temperature extremes. associated with the use of genetically engineered crops due to improved insect and . Conventional breeding also produces yield increases, so crop improvement benefits from both conventional Disclosure techniques and from genetic engineering. The author declares no conflict of interest (past or present) with respect to genetic engineering. Reduced labor costs No funding was solicited or provided by any entity Genetically engineered crops that allow for pesticide for the creation of this publication. For a complete reductions often mean that labor costs are reduced. review of this topic please see the publication It is important to note that reduced labor needs may entitled Genetically Engineered Crops: Emerging affect local employment, which can be a negative Opportunities (PPA-47) http://www2.ca.uky.edu/ consequence of improved farming efficiency. agcomm/pubs/PPA/PPA47/PPA47.pdf

October 2016 Photos Steve Patton (1), Paul Vincelli (2 & 3) and Ricardo Bessin (4), University of Kentucky; and Andrej Kunca, National Forest Center-Slovakia (5) and HD Catling (6), Bugwood.org

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