Genetically modified rice are rice strains that have been genetically modified (also called genetic engineering). Rice plants have been modified to increase micronutrients such as vitamin A, accelerate photosynthesis, tolerate herbicides, resist pests, increase grain size, generate nutrients, flavors or produce human proteins.[1]
The natural movement of genes across species, often called horizontal gene transfer or lateral gene transfer, can also occur with rice through gene transfer mediated by natural vectors. Transgenic events between rice and Setaria millet have been identified.[2] The cultivation and use of genetically modified varieties of rice remains controversial and is not approved in some countries.
History
In 2000, the first two GM rice varieties both with herbicide-resistance, called LLRice60 and LLRice62, were approved in the United States. Later, these and other types of herbicide-resistant GM rice were approved in Canada, Australia, Mexico and Colombia. However, none of these approvals triggered commercialization.[3]Reuters reported in 2009 that China had granted biosafety approval to GM rice with pest resistance,[4] but that strain was not commercialized. As of December 2012 GM rice was not widely available for production or consumption.[5] Research suggests that since rice is a staple crop across the world, improvements have potential to alleviate hunger, malnutrition and poverty.[6]
As of 2021, salt-tolerant "seawater" rice in China had been planted on 400,000ha (990,000 acres) in soils with up to 4 grams of salt per kilogram, with yields averaging 8.8 tons per hectare, according to Qingdao Saline-Alkali Tolerant Rice Research and Development Center.[8]
Traits
Herbicide resistance
In 2000–2001 Monsanto researched adding glyphosate tolerance to rice but did not attempt to bring a variety to market.[9][10]Bayer's line of herbicide resistant rice is known as LibertyLink.[11] LibertyLink rice is resistant to glufosinate (the active chemical in Liberty herbicide).[10] Bayer CropScience is attempting to get their latest variety (LL62) approved for use in the EU. The strain is approved for use in the US but is not in large-scale use. Clearfield rice was bred by selection from variations created in environments known to cause accelerated rates of mutations.[12] This variety tolerates imidazole herbicides.[13] It was bred by traditional breeding techniques that are not considered to be genetic engineering.[12][13] Clearfield is also crossbred with higher yielding varieties to produce an overall hardier plant.[12]
Golden rice with higher concentrations of Vitamin A was originally created by Ingo Potrykus and his team. This genetically modified rice is capable of producing beta-carotene in the endosperm (grain) which is a precursor for vitamin A. Syngenta was involved in the early development of Golden Rice and held some intellectual property[14] that it donated to non-profit groups including the International Rice Research Institute (IRRI) to develop on a non-profit basis.[15] The scientific details of the rice were first published in Science Magazine in 2000.[16]
Golden Rice grains (right) compared to regular rice grains (left)Golden Rice plants being grown in greenhouse
The World Health Organization stated that iron deficiency affects 30% of the world's population. Research scientists from the Australian Centre for Plant Functional Genomics (ACPFG) and IRRI to are working to increase the amount of iron in rice.[17] They have modified three populations of rice by over expressing the genes OsNAS1, OsNAS2 or OsNAS3. The research team found that nicotianamine, iron, and zinc concentration levels increased in all three populations relative to controls.[18]
Pest resistance
Bt rice
BT rice is modified to express the cryIA(b) gene of the Bacillus thuringiensisbacterium.[19] The gene confers resistance to a variety of pests including the rice borer through the production of endotoxins. The Chinese Government is doing field trials on insect resistant cultivars. The benefit of BT rice is that farmers do not need to spray their crops with pesticides to control fungal, viral, or bacterial pathogens. Conventional rice is sprayed three to four times per growing season to control pests.[20] Other benefits include increased yield and revenue from crop cultivation. China approved the rice for large-scale use as of 2009.[21]Resistance management is needed in southeast Asia to prevent loss of efficacy of Bt in rice.[22][23]
Allergy resistance
Researchers in Japan are attempting to develop hypoallergen ic rice cultivars. Researchers are trying to repress the formation of allergen AS-Albumin.[20]
Japanese researchers tested genetically modified rice on macaque monkeys that would prevent allergies to cedar pollen, which causes hay fever. Cedar allergy symptoms include itchy eyes, sneezing and other serious allergic reactions. The modified rice contains seven proteins from cedar pollen (7Crp) to block these symptoms by inducing oral tolerance.[24] Takaiwa is conducting human clinical trials with this 7Crp protein as an oral vaccine.[25]
C4 photosynthesis
In 2015 a consortium of 12 laboratories in eight countries developed a cultivar that displayed a rudimentary form of C4 photosynthesis (C4P) to boost growth by capturing carbon dioxide and concentrated it in specialized leaf cells. C4P is the reason corn and sugarcane grow so rapidly. Engineering C4 photosynthesis into rice could increase yields per hectare by roughly 50 percent. The current cultivar still relies primarily on C3 photosynthesis. To get them to completely adopt C4P, the plants must produce specialized cells in a precise arrangement: one set of cells to capture the carbon dioxide and to surround other cells that concentrate it. Some (possibly dozens of) genes involved in producing these cells remain to be identified. Other C3P crops that could exploit such knowledge include wheat, potatoes, tomatoes, apples and soybeans.[26]
Production of recombinant proteins
Human serum albumin (HSA) is a blood protein in human blood plasma. It is used to treat severe burns, liver cirrhosis and hemorrhagic shock. It is also used in donated blood and is in short supply around the world. In China, scientists modified brown rice as a cost-effective way to produce HSA protein. The Chinese scientists put recombinant HSA protein promoters into 25 rice plants using Agrobacterium. Out of the 25 plants, nine contained the HSA protein. The genetically modified brown rice makes the same amino acid sequence as HSA. They called this protein Oryza sativa recombinant HSA (OsrHSA). The modified rice was transparent. OsrHSA was soon sold to replace cow albumin for growing cells.[27] Clinical trials were started in China in 2017, and in the US in 2019.[28] The same Oryzogen company makes other recombinant human proteins from rice.
While rice grows in water, it cannot survive floods which in 2010 led to loss of 4 millions of tons of rice in India and Bangladesh alone. Addition of a single gene Sub1A[31] was sufficient to allow rice to survive underwater for up to two weeks. The gene is in the public domain.[32]
Salt tolerance
Salt-tolerant rice has been successfully cultivated in soils containing 4 grams of salt per kilogram. This involved tweaking the interaction of two genes.[33]
In the summer of 2006, the USDA detected trace amounts of LibertyLink variety 601 in rice shipments ready for export. LL601 was not approved for food purposes.[37] Bayer applied for deregulation of LL601 in late July and the USDA granted deregulation status in November 2006.[38] The contamination led to a dramatic dip in rice futures markets with losses to farmers who grew rice for export.[37] Approximately 30 percent of rice production and 11,000 farmers in Arkansas, Louisiana, Mississippi, Missouri and Texas were affected.[37] In June 2011 Bayer agreed to pay $750 million in damages and lost harvests.[37] Japan and Russia suspended rice imports from the U.S., while Mexico and the European Union refused to impose strict testing. The contamination occurred between 1998 and 2001.[39] The exact cause of the contamination was not discovered.
China
The Chinese government does not issue commercial usage licenses for genetically modified rice. All GM rice is approved for research only. Pu, et al., stated that rice engineered to produce human blood protein (HSA) requires a lot of modified rice to be grown. This raised environmental safety concerns about gene flow. They argued that this would not be a problem because rice is a self-pollinating crop, and their test showed less than 1% of the modified gene transferred in pollination.[27] Another study suggested that insect-mediated gene flow may be higher than previously assumed.[40]
Genetically modified maize (corn) is a genetically modified crop. Specific maize strains have been genetically engineered to express agriculturally-desirable traits, including resistance to pests and to herbicides. Maize strains with both traits are now in use in multiple countries. GM maize has also caused controversy with respect to possible health effects, impact on other insects and impact on other plants via gene flow. One strain, called Starlink, was approved only for animal feed in the US but was found in food, leading to a series of recalls starting in 2000.
A genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination". A wide variety of organisms have been genetically modified (GM), including animals, plants, and microorganisms.
Genetic engineering, also called genetic modification or genetic manipulation, is the modification and manipulation of an organism's genes using technology. It is a set of technologies used to change the genetic makeup of cells, including the transfer of genes within and across species boundaries to produce improved or novel organisms. New DNA is obtained by either isolating and copying the genetic material of interest using recombinant DNA methods or by artificially synthesising the DNA. A construct is usually created and used to insert this DNA into the host organism. The first recombinant DNA molecule was made by Paul Berg in 1972 by combining DNA from the monkey virus SV40 with the lambda virus. As well as inserting genes, the process can be used to remove, or "knock out", genes. The new DNA can be inserted randomly, or targeted to a specific part of the genome.
Agricultural biotechnology, also known as agritech, is an area of agricultural science involving the use of scientific tools and techniques, including genetic engineering, molecular markers, molecular diagnostics, vaccines, and tissue culture, to modify living organisms: plants, animals, and microorganisms. Crop biotechnology is one aspect of agricultural biotechnology which has been greatly developed upon in recent times. Desired trait are exported from a particular species of Crop to an entirely different species. These transgene crops possess desirable characteristics in terms of flavor, color of flowers, growth rate, size of harvested products and resistance to diseases and pests.
Genetically modified foods, also known as genetically engineered foods, or bioengineered foods are foods produced from organisms that have had changes introduced into their DNA using various methods of genetic engineering. Genetic engineering techniques allow for the introduction of new traits as well as greater control over traits when compared to previous methods, such as selective breeding and mutation breeding.
Pharming, a portmanteau of "farming" and "pharmaceutical", refers to the use of genetic engineering to insert genes that code for useful pharmaceuticals into host animals or plants that would otherwise not express those genes, thus creating a genetically modified organism (GMO). Pharming is also known as molecular farming, molecular pharming or biopharming.
Genetically modified crops are plants used in agriculture, the DNA of which has been modified using genetic engineering methods. Plant genomes can be engineered by physical methods or by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors. In most cases, the aim is to introduce a new trait to the plant which does not occur naturally in the species. Examples in food crops include resistance to certain pests, diseases, environmental conditions, reduction of spoilage, resistance to chemical treatments, or improving the nutrient profile of the crop. Examples in non-food crops include production of pharmaceutical agents, biofuels, and other industrially useful goods, as well as for bioremediation.
A transgene is a gene that has been transferred naturally, or by any of a number of genetic engineering techniques, from one organism to another. The introduction of a transgene, in a process known as transgenesis, has the potential to change the phenotype of an organism. Transgene describes a segment of DNA containing a gene sequence that has been isolated from one organism and is introduced into a different organism. This non-native segment of DNA may either retain the ability to produce RNA or protein in the transgenic organism or alter the normal function of the transgenic organism's genetic code. In general, the DNA is incorporated into the organism's germ line. For example, in higher vertebrates this can be accomplished by injecting the foreign DNA into the nucleus of a fertilized ovum. This technique is routinely used to introduce human disease genes or other genes of interest into strains of laboratory mice to study the function or pathology involved with that particular gene.
Since the advent of genetic engineering in the 1970s, concerns have been raised about the dangers of the technology. Laws, regulations, and treaties were created in the years following to contain genetically modified organisms and prevent their escape. Nevertheless, there are several examples of failure to keep GM crops separate from conventional ones.
Genetically modified food controversies are disputes over the use of foods and other goods derived from genetically modified crops instead of conventional crops, and other uses of genetic engineering in food production. The disputes involve consumers, farmers, biotechnology companies, governmental regulators, non-governmental organizations, and scientists. The key areas of controversy related to genetically modified food are whether such food should be labeled, the role of government regulators, the objectivity of scientific research and publication, the effect of genetically modified crops on health and the environment, the effect on pesticide resistance, the impact of such crops for farmers, and the role of the crops in feeding the world population. In addition, products derived from GMO organisms play a role in the production of ethanol fuels and pharmaceuticals.
Genetically modified plants have been engineered for scientific research, to create new colours in plants, deliver vaccines, and to create enhanced crops. Plant genomes can be engineered by physical methods or by use of Agrobacterium for the delivery of sequences hosted in T-DNA binary vectors. Many plant cells are pluripotent, meaning that a single cell from a mature plant can be harvested and then under the right conditions form a new plant. This ability is most often taken advantage by genetic engineers through selecting cells that can successfully be transformed into an adult plant which can then be grown into multiple new plants containing transgene in every cell through a process known as tissue culture.
Plant genetics is the study of genes, genetic variation, and heredity specifically in plants. It is generally considered a field of biology and botany, but intersects frequently with many other life sciences and is strongly linked with the study of information systems. Plant genetics is similar in many ways to animal genetics but differs in a few key areas.
The United States is the largest grower of commercial crops that have been genetically engineered in the world, but not without domestic and international opposition.
Genetically modified wheat is wheat that has been genetically engineered by the direct manipulation of its genome using biotechnology. As of 2020, no GM wheat is grown commercially, although many field tests have been conducted, with one wheat variety, Bioceres HB4 Wheat, obtaining regulatory approval from the Argentinean government.
A genetically modified soybean is a soybean that has had DNA introduced into it using genetic engineering techniques. In 1996, the first genetically modified soybean was introduced to the U.S. by Monsanto. In 2014, 90.7 million hectares of GM soybeans were planted worldwide, this is almost 82% of the total soybeans cultivation area.
Genetically modified canola is a genetically modified crop. The first strain, Roundup Ready canola, was developed by Monsanto for tolerance to glyphosate, the active ingredient in the commonly used herbicide Roundup.
The regulation of genetic engineering varies widely by country. Countries such as the United States, Canada, Lebanon and Egypt use substantial equivalence as the starting point when assessing safety, while many countries such as those in the European Union, Brazil and China authorize GMO cultivation on a case-by-case basis. Many countries allow the import of GM food with authorization, but either do not allow its cultivation or have provisions for cultivation, but no GM products are yet produced. Most countries that do not allow for GMO cultivation do permit research. Most (85%) of the world's GMO crops are grown in the Americas. One of the key issues concerning regulators is whether GM products should be labeled. Labeling of GMO products in the marketplace is required in 64 countries. Labeling can be mandatory up to a threshold GM content level or voluntary. A study investigating voluntary labeling in South Africa found that 31% of products labeled as GMO-free had a GM content above 1.0%. In Canada and the USA labeling of GM food is voluntary, while in Europe all food or feed which contains greater than 0.9% of approved GMOs must be labelled.
Genetic engineering is the science of manipulating genetic material of an organism. The first artificial genetic modification accomplished using biotechnology was transgenesis, the process of transferring genes from one organism to another, first accomplished by Herbert Boyer and Stanley Cohen in 1973. It was the result of a series of advancements in techniques that allowed the direct modification of the genome. Important advances included the discovery of restriction enzymes and DNA ligases, the ability to design plasmids and technologies like polymerase chain reaction and sequencing. Transformation of the DNA into a host organism was accomplished with the invention of biolistics, Agrobacterium-mediated recombination and microinjection. The first genetically modified animal was a mouse created in 1974 by Rudolf Jaenisch. In 1976 the technology was commercialised, with the advent of genetically modified bacteria that produced somatostatin, followed by insulin in 1978. In 1983 an antibiotic resistant gene was inserted into tobacco, leading to the first genetically engineered plant. Advances followed that allowed scientists to manipulate and add genes to a variety of different organisms and induce a range of different effects. Plants were first commercialized with virus resistant tobacco released in China in 1992. The first genetically modified food was the Flavr Savr tomato marketed in 1994. By 2010, 29 countries had planted commercialized biotech crops. In 2000 a paper published in Science introduced golden rice, the first food developed with increased nutrient value.
Dhara Mustard Hybrid-11, otherwise known as DMH - 11, is a genetically modified hybrid variety of the mustard species Brassica juncea. It was developed by Professor Deepak Pental from the University of Delhi, with the aim of reducing India's demand for edible oil imports. DMH - 11 was created through transgenic technology, primarily involving the Bar, Barnase and Barstar gene system. The Barnase gene confers male sterility, while the Barstar gene restores DMH - 11's ability to produce fertile seeds. The insertion of the third gene Bar, enables DMH - 11 to produce phosphinothricin-N- acetyl-transferase, the enzyme responsible for Glufosinate resistance. This hybrid mustard variety has come under intense public scrutiny, mainly due to concerns regarding DMH - 11's potential to adversely affect the environment as well as consumer health. DMH - 11 was found not to pose any food allergy risks, and has demonstrated increased yields over existing mustard varieties. Conflicting details and results regarding the field trials and safety evaluations conducted on DMH - 11 have delayed its approval for commercial cropping.
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