Genetically modified corn (corn) is a genetically engineered plant. Specific corn types have been genetically engineered to express desirable agricultural features, including resistance to pests and herbicides. Corn strains with both properties are now used in some countries. GM corn has also caused controversy with respect to possible health effects, affecting other insects and impacting other plants through gene flow. One strain, called Starlink, is approved only for animal feed in the US, but is found in food, leading to a series of withdrawals beginning in 2000.
Video Genetically modified maize
Products marketed
Herbicide resistant corn
The maize-tolerant varieties of glyphosate herbicide were first commercialized in 1996 by Monsanto, and known as the "Roundup Ready Corn". They tolerate the use of Roundup. Bayer CropScience develops a "Liberty Link Corn" that is resistant to glufosinate. Pioneer Hi-Bred has developed and marketed corn hybrids with tolerance to imidazoline herbicides under the "Clearfield" trademark - although in this hybrid, herbicide tolerant properties are bred using tissue culture selection and chemical mutagenic of ethyl metanatulfonate, not genetically modified. Consequently, the regulatory framework governing the approval of transgenic crops does not apply to Clearfield.
In 2011, GM-resistant herbicide maize was grown in 14 countries. In 2012, 26 herbicide-resistant GM corn varieties were allowed to be imported into the EU, but such imports are still controversial. Herbicide-resistant maize cultivation in the EU provides great benefits at the farm level.
insect-resistant corn
Bt Corn is a variant of genetically altered corn to express one or more proteins from Bacillus thuringiensis bacteria including Delta endotoxin. Protein is toxic to certain insect pests. Spores from bacillus are widely used in organic gardening, although GM corn is not considered organic. The European corn borer causes about a billion dollars of damage to corn crops every year.
In recent years, traits have been added to ward off earworms of corn and root worms, the latter each year causing about a billion dollars in damage.
Bt protein is expressed throughout the plant. When a susceptible insect eats a plant containing Bt, the protein is activated in its intestine, which is alkaline. In a protein-base environment partially dismantled and cut by other proteins, forming toxins that paralyze the digestive system of insects and form holes in the intestinal wall. The insects stopped eating within a few hours and eventually became starved.
In 1996, the first GM corn producing Bt Cry protein was approved, which kills the European corn borer and related species; the next Bt gene introduced that kills the larvae of the cornworm.
The approved Bt genes include single and stacked configuration (event names bracketed): Cry1A.105 (MON89034), CryIAb (MON810), CryIF (1507), Cry2Ab (MON89034), Cry3Bb1 (MON863 and MON88017), Cry34Ab1 (59122 ), Cry35Ab1 (59122), mCry3A (MIR604), and Vip3A (MIR162), both corn and cotton. Genetically modified corn to produce VIPs was first approved in the US in 2010.
In 2018 a study found that Bt-maize protected nearby non-Bt cornfields and nearby vegetable crops, reducing the use of pesticides in these crops. Data from 1976-1996 (before Bt corn is widespread) compared with data after adoption (1996-2016). They checked the level of European corn borer and corn earworm. Their larvae feed on a variety of plants, including chili and green beans. Between 1992 and 2016, the number of insecticides used for the New Jersey pepper field decreased by 85 percent. Another factor is the introduction of more effective pesticides that are rarely used.
Sweet corn
GM sweet corn varieties include "Attributes", brand names for insect-resistant sweet corn developed by Syngenta and Insect-resistant sweet corn Series (TM) developed by Monsanto.
drought-resistant corn
In 2013 Monsanto launched the first transgenic drought tolerance property in a line of corn hybrids called DroughtGard. The properties of MON 87460 are given by the insertion of the cspB gene from the soil microbes Bacillus subtilis ; approved by the USDA in 2011 and by China in 2013.
Corn with increased nutritional value
Research has been done to add one E. coli gene to corn to allow it to be grown with essential amino acids (methionine).
Maps Genetically modified maize
Products under development
In 2007, South African researchers announced the production of transgenic corn resistant to the maize virus (MSV), though it has not been released as a product.
While breeding cultivars for resilience to MSV are not conducted in the public, private sector, international research centers, and national programs have undertaken all breeding.
By 2014, there have been several MSV tolerant cultivars released in Africa. A private company Seedco has released 5 MSV cultivars. Refuges
The US Environmental Protection Agency's (EPA) regulations require farmers growing Bt corn to grow nearby non-Bt maize (called shelters) to provide a location to accommodate vulnerable pests. Typically, 20% of corn in a farmer's field should be a shelter; displacement should be at least 0.5 miles of Bt corn for lepidopteran pests, and protection for cornworms should be at least adjacent to Bt terrain.
The theory behind this protection is to slow down the evolution of resistance to pesticides. The EPA regulations also require seed companies to train farmers how to maintain protection, to collect data in shelters and to report the data to the EPA. A study of these reports found that from 2003 to 2005 farmers' compliance with protectionism was above 90%, but in 2008 about 25% of Bt maize farmers did not maintain proper shelters, raising fears that resistance will develop.
Unmodified plants received most of the economic benefits of Bt corn in the US in 1996-2007, due to the overall pest population reduction. This reduction occurs because the female spawns on a modified and unmodified derivative.
Seed bags containing Bt and refuge seeds have been approved by the EPA in the United States. This seed mixture is marketed as "Refuge in a Bag" (RIB) to improve farmer compliance with evacuation requirements and reduce the additional work required when planting from separating Bt and reserve seed bags in hand. EPA approves a lower percentage of seed protection in this seed mixture ranging from 5 to 10%. This strategy is likely to reduce the likelihood of B-resistance occurring for corn root worms, but may increase the risk of resistance to lepidopteran pests, such as the European corn borer. Increased concern for endurance with seed mixtures includes partially resistant larvae in Bt plants that can move to vulnerable plants to survive or cross pollination pollen to Bt crops that can decrease the amount of Bt expressed in the kernel for ear-eating insects.
Resistance
Resistant strains from European corn borer have grown in areas with flawed or non-existent displacement management.
In November 2009, Monsanto scientists discovered the pink bollworm had become resistant to first generation Bt cotton in parts of Gujarat, India - the generation expressed one Bt gene, Cry1Ac . This is the first example of Bt resistance confirmed by Monsanto anywhere in the world. Bollworm resistance for first generation Bt cotton has been identified in Australia, China, Spain, and the United States. In 2012, a Florida field trial showed that the army worms were resistant to GM corn containing pesticides produced by Dupont-Dow; The durability of grayak worms was first discovered in Puerto Rico in 2006, which prompted Dow and DuPont to voluntarily stop selling products on the island.
Rule
GM crop regulation varies across countries, with some of the most striking differences between the United States and Europe. Regulations vary in certain countries depending on the intended use.
Controversy
There is a scientific consensus that currently available foods derived from GM crops have no greater risk to human health than conventional foods, but that every GM food should be tested on a case-by-case basis before introduction. Nonetheless, community members are far more likely than scientists to assume GM food is safe. GM's legal status and food rules vary by country, with some countries banning or restricting them, and others allowing them at very different levels of regulation.
The scientific rigor of the study on human health has been debated because of the alleged lack of independence and because of conflicts of interest involving regulatory bodies and some of those conducting and evaluating studies.
Genetically modified crops provide a number of ecological benefits, but there are also concerns for their excessive and stalled research beyond the Bt seed industry, proper management and problems with Bt resistance arising from their abuse.
Critics object to genetically modified crops for ecological, economic and health reasons. Economic problems come from organisms that are subject to intellectual property laws, mostly patents. The first generation of genetically engineered crops lost patent protection beginning in 2015. Monsanto claims it will not pursue farmers who retain seeds of off-patent varieties. These controversies have led to litigation, international trade disputes, restrictive protests and legislation in most countries.
Effects on non-targeted insects
Critics claim that Bt protein can target predators and other beneficial or harmless insects as well as targeted pests. This protein has been used as an organic spray for insect control in France since 1938 and the United States since 1958 with no adverse effects on the reported environment. While the protein cyt is toxic to the Diptera insect (fly), certain proteins cry selectively target lepidopteran (moths and butterflies), while others cyt selectively target Coleoptera. As a toxic mechanism, cry binds proteins to specific receptors on the membrane of the mid-gut (epithelial) cells, resulting in the breakup of these cells. Any organism that does not have an appropriate intestinal receptor can not be affected by the protein cry , and therefore Bt. Regulatory bodies assess the potential of transgenic crops to influence target organisms before approving commercial release.
A 1999 study found that in the laboratory environment, the pollen from Bt corn sprinkled on milkweed can damage the king's butterfly. Several groups then studied field and laboratory phenomena, yielding a risk assessment that concluded that any risk posed by the maize population to butterflies under real-world conditions is negligible. A review of the scientific literature in 2002 concluded that "commercial large-scale cultivation of the current Bt-corn hybrids poses no significant risk to the king's population". A 2007 review found that "non-targeted invertebrates are generally more abundant in the Bt and Bt cotton fields than in the non-GMO field managed by insecticides, but compared to the insecticide-free control field, certain target taxa are less abundant in the Bt field."
Gene flow
Gene flow is the transfer of genes and/or alleles from one species to another. Concerns focus on the interaction between GM and other maize varieties in Mexico, and the genes flow into the shelter.
In 2009 the Mexican government created regulatory paths for genetically engineered corn, but because Mexico is the center of diversity for corn, gene flow can affect most of the world's corn strains. The 2001 report in Nature provides evidence that Bt corn is cross-breeding with unmodified corn in Mexico. The data in this paper is then described as derived from artifacts. Nature then stated, "the available evidence is insufficient to justify the publication of the original paper". Large-scale research in 2005 failed to find any evidence of contamination in Oaxaca. However, other authors also found evidence of cross-breeding between natural corn and transgenic maize.
A 2004 study found Bt protein in the refuge corn kernel.
In 2017, a large-scale study found "the presence of transgenes and glyphosate in maize-derived foods in Mexico"
Food
The French Biotechnology Scientific Committee of the Higher Committee reviewed the study of VendÃÆ'Â'mois et al. in 2009 and concludes that "... there is no acceptable scientific element that tends to assume hematological, hepatic or renal toxicity against the third re-analyzing the GMO." However, the French government applies the precautionary principle with respect to GMOs.
A review by Food Standards Australia New Zealand and others from the same study concluded that the result was due to chance alone.
A 2011 Canadian study looked at the presence of CryAb1 protein (BT toxin) in non-pregnant women, pregnant women and fetal blood. All groups had detectable protein levels, including 93% of pregnant women and 80% of fetuses at concentrations of 0.19 Â ± 0.30 and 0.04 Â ± 0.04 mean Ã, Â ± SD ng/ml, respectively -something. This paper does not address security implications or find any health problems. This paper was found to be inconclusive by many authors and organizations. In the pig model, Cry1Ab-specific antibodies are not detected in pregnant pigs or offspring and there is no negative effect of Bt corn administration to pregnant mothers.
In January 2013, the European Food Safety Authority released all data submitted by Monsanto in connection with a genetically modified corn authorization in 2003 for glyphosate tolerance.
Starlink corn recalls
StarLink contains Cry9C, which was not previously used in GM crops. Starlink creator Plant Genetic Systems has applied to the US Environmental Protection Agency (EPA) to market StarLink for use in animal feed and human food. However, since Cry9C protein lasts longer in the digestive system than other Bt proteins, the EPA has concerns about its allergenicity, and PGS does not provide sufficient data to prove that Cry9C does not cause allergies. As a result, PGS divides its application into separate permits for use in food and used in animal feed. Starlink approved by EPA for use in animal feed only in May 1998.
Corn StarLink is later found in foods destined for human consumption in the US, Japan and South Korea. This corn is fueled by Starlink's widely-publicized corn memory, which began when the Taco Bell taco chips sold in the supermarket were found to contain corn. StarLink seed sales stopped. The registration for the Starlink variety was voluntarily withdrawn by Aventis in October 2000. (Pioneer was bought by AgrEvo who later became Aventis CropScience at the time of the incident, which was later purchased by Bayer
Fifty-one people reported side effects on the FDA; The US Centers for Disease Control (CDC), which stipulates that 28 of them may be related to Starlink. However, the CDC studied the blood of these 28 individuals and concluded there was no evidence of hypersensitivity to Starlink Bt protein.
The subsequent review of this test by the Federal Insecticide, Fungicide, and Rodenticide Act Scientific Advisory Panel shows that while "negative results decrease the probability that Cry9C protein is the cause of allergic symptoms in investigated individuals... in the absence of positive control and questions about sensitivity and specificity from testing, it is not possible to set a negative predictive value for this. "
US corn supplies have been monitored for the presence of Starlink Bt protein since 2001.
In 2005, aid sent by the United Nations and the United States to Central American countries also contained some StarLink maize. The countries involved, Nicaragua, Honduras, El Salvador and Guatemala refused to accept the aid.
Company espionage
On December 19, 2013, six Chinese were indicted in Iowa for allegedly planning to steal genetically modified seeds worth tens of millions of dollars from Monsanto and DuPont. Mo Hailong, international business director at Beijing Dabeinong Technology Group Co., part of the Beijing-based DBN Group, was accused of stealing trade secrets after he was discovered digging in the Iowa corn field.
See also
- Genetically engineered food
- Genetically engineered plants
- Genetically modified food controversy
References
External links
- List of approved varieties
- GMO Safety - A review of biological safety research projects on genetically engineered corn funded by the Federal Ministry of Education and Research (BMBF)
- Co-Extra - research project on coexistence and traceability of GM and non-GM supply chains
- EFSA discussion GMO Panel on Austrian report "Biological effects of transgenic maize NK603 x MON 810 feeding in long-term reproductive study in mice" (Part of the minutes of the plenary meeting held on 3-4 December 2008, see on page 9)
Source of the article : Wikipedia
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