Genetically modified plant
Encyclopedia
Genetically modified plants are plants whose DNA
is modified using genetic engineering
techniques. In most cases the aim is to introduce a new trait
to the plant which does not occur naturally in this species. Examples include resistance to certain pests, diseases or environmental conditions, or the production of a certain nutrient or pharmaceutical agent.
Some degree of natural flow of genes, often called horizontal gene transfer
or lateral gene transfer, occurs between plant species. This is facilitated by transposon
s, retrotransposon
s, provirus
es and other mobile genetic elements
that naturally translocate to new sites in a genome
. They often move to new species over an evolutionary time scale and play a major role in dynamic changes to chromosomes during evolution.
The introduction of foreign germplasm
into common foods has been achieved by traditional crop breeders by artificially overcoming fertility barriers. A hybrid cereal
was created in 1875, by crossing wheat
and rye
. Since then important traits have been introduced into wheat, including dwarfing genes
and rust resistance
. Plant tissue culture
and the induction of mutation
s have also enabled humans to artificially alter the makeup of plant genomes.
The first field trials of genetically engineered plants occurred in France and the USA in 1986, when tobacco plants were engineered to be resistant to herbicide
s. In 1987, Plant Genetic Systems
(Ghent
, Belgium
), founded by Marc Van Montagu
and Jeff Schell, was the first company to develop genetically engineered (tobacco
) plants with insect tolerance by expressing genes encoding for insecticidal proteins from Bacillus thuringiensis
(Bt). The People’s Republic of China was the first country to allow commercialized transgenic plants, introducing a virus-resistant tobacco in 1992. The first genetically modified crop approved for sale in the U.S., in 1994, was the FlavrSavr
tomato, which had a longer shelf life. In 1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil
, making it the first commercially genetically engineered crop marketed in Europe. In 1995, Bt Potato was approved safe by the Environmental Protection Agency, making it the first pesticide producing crop to be approved in the USA. In 2010, 11 different transgenic crops were grown commercially on 365 million acres (148 million hectares) in 29 countries such as the USA, Brazil, Argentina, India, Canada, China, Paraguay, Pakistan, South Africa and Uraguay.
The U.S. has adopted the technology most widely whereas Europe has very little genetically engineered crops with the exception of Spain where one fifth of maize grown is genetically engineered, and smaller amounts in five other countries. The EU had a 'de facto' ban on the approval of new GM crops, from 1999 until 2004; in a controversial move. GM crops are now regulated by the EU. Developing countries grew 48 per cent of genetically engineered crops in 2010.
Genetically engineered plants are generated in a laboratory by altering the genetic makeup, usually by adding one or more gene
s, of a plant's genome
using genetic engineering
techniques. Most genetically modified plants are generated by the biolistic method
(particle gun) or by Agrobacterium tumefaciens
mediated transformation.
In the biolistic method, DNA
is bound to tiny particles of gold or tungsten which are subsequently "shot" into plant tissue or single plant cells under high pressure. The accelerated particles penetrate both the cell wall
and membrane
s. The DNA separates from the metal and is integrated into the plant genome
inside the nucleus
. This method has been applied successfully for many cultivated crops, especially monocots like wheat or maize, for which transformation
using Agrobacterium tumefaciens has been less successful. The major disadvantage of this procedure is that serious damage can be done to the cellular tissue.
Agrobacteria are natural plant parasites, and their natural ability to transfer genes is used for the development of genetically engineered plants. To create a suitable environment for themselves, these Agrobacteria insert their genes into plant hosts, resulting in a proliferation of plant cells near the soil level (crown gall). The genetic information for tumour growth is encoded on a mobile, circular DNA fragment (plasmid
). When Agrobacterium infects a plant, it transfers this T-DNA
to a random site in the plant genome. When used in genetic engineering the bacterial T-DNA is removed from the bacterial plasmid and replaced with the desired foreign gene. The bacterium is a vector, enabling transportation of foreign genes into plants. This method works especially well for dicotyledon
ous plants like potatoes, tomatoes, and tobacco. Agrobacteria infection is less successful in crops like wheat and maize.
Genetically modified plants have been developed commercially to improve shelf life
, disease resistance, herbicide resistance and pest resistance. Plants engineered to tolerate non-biological stresses like drought
, frost
and nitrogen starvation or with increased nutritional value
(e.g. Golden rice
) were in development in 2011. Future generations of GM plants are intended to be suitable for harsh environments, produce increased amounts of nutrients or even pharmaceutical agents, or are improved for the production of bioenergy and biofuels. Due to high regulatory and research costs, the majority of genetically modified crops in agriculture consist of commodity crops, such as soybean, maize, cotton and rapeseed. However, commercial growing was reported in 2009, of smaller amounts of genetically modified sugar beet, papayas, squash (zucchini), sweet pepper, tomatoes, petunias, carnations, roses and poplars. Recently, some research and development
has been targeted to enhancement of crops that are locally important in developing countries, such as insect-resistant cowpea
for Africa and insect-resistant brinjal
(eggplant) for India.
In research tobacco
and Arabidopsis thaliana
are the most genetically modified plants, due to well developed transformation methods, easy propagation and well studied genomes. They serve as model organisms for other plant species. Genetically modified plants have also been used for bioremediation
of contaminated soils. Mercury
, selenium
and organic pollutants such as polychlorinated biphenyl
s (PCBs) have been removed from soils by transgenic plants containing gene
s for bacterial enzymes.
Transgenic
plants have genes inserted into them that are derived from another species. The inserted genes can come from species within the same kingdom
(plant to plant) or between kingdoms (bacteria to plant). In many cases the inserted DNA has to be modified slightly in order to correctly and efficiently express
in the host organism. Transgenic plants are used to express proteins like the cry toxins from Bacillus thuringiensis
, herbicide
resistant genes and antigens for vaccination
s
Cisgenic
plants are made using genes found within the same species or a closely related one, where conventional plant breeding
can occur. Some breeders and scientists argue that cisgenic modification is useful for plants that are difficult to crossbreed
by conventional means (such as potatoes), and that plants in the cisgenic category should not require the same level of legal regulation as other genetically modified organisms.
In research plants are engineered to help discover the functions of certain genes. One way to do this is to knock out the gene of interest and see what phenotype
develops. Another strategy is to attach the gene to a strong promoter and see what happens when it is over expressed. A common technique used to find out where the gene is expressed is to attach it to GUS
or a similar reporter gene
that allows visualisation of the location.
The first commercialised genetically modified plants (Flavr Savr tomatoes) used RNAi
technology, where the inserted DNA matched an endogenous
gene already in the plant. When the inserted gene is expressed it can repress the translation
of the endogenous protein. Host delivered RNAi systems are being developed, where the plant will express RNA
that will interfere with insects, nematodes and other parasites protein synthesis. This may provide a novel way of protecting plants from pests.
(FDA) and the Environmental protection agency (EPA). The USDA evaluate the plants potential to become weeds, the FDA review plants that could enter or alter the food supply and the EPA regulate the genetically modified plants with pesticide properties. Most developed genetically modified plants are reviewed by at least two of the agencies, with many subject to all three. Final approval can still be denied by individual counties within each state. In 2004, Mendocino County
, California became the first and only county to impose a ban on the "Propagation, Cultivation, Raising, and Growing of Genetically Modified Organisms", the measure passing with a 57% majority.
Allergic proteins were detected during testing of a transgenic soybean
inserted with a gene from the Brazil nut
. The inserted gene did not translate
into a known allergen, the allergenic nature of the protein was discovered when tested with serum from people allergic to Brazil nut. Four federal district court
suits
have been brought against Animal and Plant Health Inspection Service, the agency within USDA that regulates genetically modified plants. Two involved field trials (herbicide-tolerant turfgrass in Oregon
; pharmaceutical-producing corn and sugar in Hawaii
) and two the deregulation of GM alfalfa
. and GM sugar beet. Initially APHIS lost all four cases, with the judges ruling they failed to diligently follow the guidelines set out in the National Environmental Policy Act
. In 2010 the US Supreme Court nullified the district court ban on growing GM alfalfa. and in 2011 an appeal court allowed the partial deregulation of GM sugar beet.
The European Union
(EU) has possibly the most stringent regulations for genetically modified plants in the world. All genetically modified plants are considered "new food" and subject to extensive, case-by-case, science based food evaluation by the European Food Safety Authority
(EFSA). The European Commission
(EC) then draft a proposal that is submitted to the Section on GM Food and Feed of the Standing Committee on the Food Chain and Animal Health, where if accepted it will be adopted by the EC or passed on to the Council of Agricultural Ministers
. There is also a safeguard clause that any Member State
can invoke to restrict or prohibit the use or sale of a GM plant within their territory if they have a justifiable reasons to consider that the approved GM plant constitutes a risk to human health or the environment.
Currently (2010) the only genetically modified plants approved for cultivation in Europe are MON810, a Bt expressing maize
conferring resistance to the European corn borer
and a potato called Amflora
, approved only for industrial applications. The EC has issued guidelines to allow the co-existence of GM and non-GM crops
through buffer zones (where no GM crops are grown). These are regulated by individual countries and vary from 15 meters in Sweden to 800 meters in Luxembourg. All food (including processed food) or feed
which contains greater than 0.9% of approved GMOs must be labelled.
Regulation in Australia are provided by the Office of the Gene Technology Regulator
and Food Standards Australia New Zealand
. Each state in Australia individually assess the impact of release on markets and trade and can apply further legislation if they deem it necessary. In 2011 genetically modified plants were grown in all states except South Australia and Tasmania, who have extended their moratoriums until 2019 and 2014. Health Canada
and the Canadian Food Inspection Agency
are responsible for evaluating the safety and nutritional value of genetically modified plants in Canada.
The Argentine government was one of the first to accept genetically modified plants, with assessment provided by the National Agricultural Biotechnology Advisory Committee (for environmental impact), the National Service of Health and Agrifood Quality (for food safety) and the National Agribusiness Direction (for theeffect on trade) The final decision is made by the Secretariat of Agriculture, Livestock, Fishery and Food. In Brazil the 27 member National Biosafety Technical Commission is responsible for assessing environmental impact, food safety and provides guidelines for transport, importation and field experiments. In 2005, the Mexican senate passed a law allowing planting and selling of genetically modified crops.
Genetically modified crops in China go through three phases of field trials (pilot field testing, environmental release testing, and preproduction testing) before they are submitted to the Office of Agricultural Genetic Engineering Biosafety Administration (OAGEBA) for assessment. The 75 member National Biosafety Committee evaluates all applications, although OAGEBA has the final decision. The cost of regulation enforcement in India is generally higher than China, while the enforcement of regulations has proved more effective in China. The National Assembly of Burkina Faso passed a biosafety law in early 2006, which established a National Biosafety Agency that would regulate GM products with the advise of various governmental and non-governmental advisory committees.
Therefore, in most countries environmental studies are required prior to the approval of a GM plant for commercial purposes, and a monitoring plan must be presented to identify potential effects which have not been anticipated prior to the approval.
Little research has been conducted on human and animal health. However, in most countries every GM plant is tested in feeding trials to prove its safety, before it is approved for use and marketing. The project GMO-Safety collects and presents biosafety research on GMOs with more in-depth information on this topic.http://www.gmo-safety.eu
The potential impact on nearby ecosystems is one of the greatest concerns associated with transgenic plants.
Transgenes have the potential for significant ecological impact if the plants can increase in frequency and persist in natural populations. These concerns are similar to those surrounding conventionally bred plant breeds. Several risk factors should be considered:
Many domesticated plants can mate and hybridise with wild relatives when they are grown in proximity, and whatever genes the cultivated plant had can then be passed to the hybrid. This applies equally to transgenic plants and conventionally bred plants, as in either case there are advantageous genes that may have negative consequences to an ecosystem upon release. This is normally not a significant concern, despite fears over 'mutant superweeds' overgrowing local wildlife: although hybrid plants are far from uncommon, in most cases these hybrids are not fertile due to polyploidy
, and will not multiply or persist long after the original domestic plant is removed from the environment. However, this does not negate the possibility of a negative impact.
In some cases, the pollen from a domestic plant may travel many miles on the wind before fertilising another plant. This can make it difficult to assess the potential harm of crossbreeding; many of the relevant hybrids are far away from the test site. Among the solutions under study for this concern are systems designed to prevent transfer of transgenes, such as Terminator Technology
, and the genetic transformation of the chloroplast
only, so that only the seed of the transgenic plant would bear the transgene. With regard to the former, there is some controversy that the technologies may be inequitable and might force dependence upon producers for valid seed in the case of poor farmers, whereas the latter has no such concern but has technical constraints that still need to be overcome. Solutions are being developed by EU funded research programmes such as Co-Extra
and Transcontainer.
There are at least three possible avenues of hybridization leading to escape of a transgene:
However, there are a number of factors which must be present for hybrids to be created.
In order to persist, these hybrid offspring:
Studies suggest that a possible escape route for transgenic plants will be through hybridization with wild plants of related species.
It is also important to refer to the demanding actions that government of developing countries had been building up among the last decades.
measures on the field level as well as traceability
measures throughout the whole food and feed processing chain. Research projects such as Co-Extra
, SIGMEA and Transcontainer investigate how farmers can avoid outcrossing and mixing of transgenic and non-transgenic crops, and how processors can ensure and verify the separation of both production chains.
, consumers demand the choice between foods derived from GM plants and conventionally or organically produced plants. This requires a labelling system as well as the reliable separation of GM and non-GM crops at field level and throughout the whole production chain.
Research has demonstrated, that coexistence
can be realised by several agricultural measures, such as isolation distances
or biological containment
strategies.http://www.coextra.eu
For traceability
, the OECD has introduced a "unique identifier" which is given to any GMO when it is approved. This unique identifier must be forwarded at every stage of processing.
Many countries have established labelling regulations and guidelines on coexistence and traceability. Research projects like Co-Extra
, SIGMEA and Transcontainer are aimed at investigating improved methods for ensuring coexistence and providing stakeholders the tools required for the implementation of coexistence and traceability.
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
is modified using genetic engineering
Genetic engineering
Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest...
techniques. In most cases the aim is to introduce a new trait
Trait (biology)
A trait is a distinct variant of a phenotypic character of an organism that may be inherited, environmentally determined or be a combination of the two...
to the plant which does not occur naturally in this species. Examples include resistance to certain pests, diseases or environmental conditions, or the production of a certain nutrient or pharmaceutical agent.
History
Horizontal gene transfer
Horizontal gene transfer , also lateral gene transfer , is any process in which an organism incorporates genetic material from another organism without being the offspring of that organism...
or lateral gene transfer, occurs between plant species. This is facilitated by transposon
Transposon
Transposable elements are sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell. The mechanism of transposition can be either "copy and paste" or "cut and paste". Transposition can create phenotypically significant mutations and alter the cell's...
s, retrotransposon
Retrotransposon
Retrotransposons are genetic elements that can amplify themselves in a genome and are ubiquitous components of the DNA of many eukaryotic organisms. They are a subclass of transposon. They are particularly abundant in plants, where they are often a principal component of nuclear DNA...
s, provirus
Provirus
A provirus is a virus genome that is integrated into the DNA of a host cell.This state can be a stage of virus replication, or a state that persists over longer periods of time as either inactive viral infections or an endogenous retrovirus. In inactive viral infections the virus will not replicate...
es and other mobile genetic elements
Mobile genetic elements
Mobile genetic elements are a type of DNA that can move around within the genome. They include:*Transposons **Retrotransposons**DNA transposons**Insertion sequences*Plasmids...
that naturally translocate to new sites in a genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
. They often move to new species over an evolutionary time scale and play a major role in dynamic changes to chromosomes during evolution.
The introduction of foreign germplasm
Germplasm
A germplasm is a collection of genetic resources for an organism. For plants, the germplasm may be stored as a seed collection or, for trees, in a nursery.-See also:*Germ plasm, the germ cell determining zone...
into common foods has been achieved by traditional crop breeders by artificially overcoming fertility barriers. A hybrid cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...
was created in 1875, by crossing wheat
Wheat
Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...
and rye
Rye
Rye is a grass grown extensively as a grain and as a forage crop. It is a member of the wheat tribe and is closely related to barley and wheat. Rye grain is used for flour, rye bread, rye beer, some whiskeys, some vodkas, and animal fodder...
. Since then important traits have been introduced into wheat, including dwarfing genes
Dwarfing
Dwarfing is a characteristic in plants and animals whereby one or more members of a breed or cultivar are significantly smaller than standard members of their species...
and rust resistance
Plant disease resistance
Plant disease resistance is crucial to the reliable production of food, and it provides significant reductions in agricultural use of fuel, land, water and other inputs. There are numerous examples of devastating plant disease impacts , as well as recurrent severe plant disease issues...
. Plant tissue culture
Plant tissue culture
Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition. Plant tissue culture is widely used to produce clones of a plant in a method known as micropropagation...
and the induction of mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s have also enabled humans to artificially alter the makeup of plant genomes.
The first field trials of genetically engineered plants occurred in France and the USA in 1986, when tobacco plants were engineered to be resistant to herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
s. In 1987, Plant Genetic Systems
Plant Genetic Systems
Plant Genetic Systems , since 2002 part of Bayer CropScience, is a biotech company located in Ghent, Belgium. The focus of its activities is the genetic engineering of plants...
(Ghent
Ghent
Ghent is a city and a municipality located in the Flemish region of Belgium. It is the capital and biggest city of the East Flanders province. The city started as a settlement at the confluence of the Rivers Scheldt and Lys and in the Middle Ages became one of the largest and richest cities of...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
), founded by Marc Van Montagu
Marc Van Montagu
Marc Van Montagu is a Belgian molecular biologist. He was full Professor and director of the Laboratory of Genetics at the faculty of Sciences at Ghent University and scientific director of the Genetics Department of the Flanders Interuniversity Institute for Biotechnology...
and Jeff Schell, was the first company to develop genetically engineered (tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
) plants with insect tolerance by expressing genes encoding for insecticidal proteins from Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
(Bt). The People’s Republic of China was the first country to allow commercialized transgenic plants, introducing a virus-resistant tobacco in 1992. The first genetically modified crop approved for sale in the U.S., in 1994, was the FlavrSavr
FlavrSavr
Flavr Savr , a genetically modified tomato, was the first commercially grown genetically engineered food to be granted a license for human consumption. It was produced by the Californian company Calgene, and submitted to the U.S. Food and Drug Administration in 1992...
tomato, which had a longer shelf life. In 1994, the European Union approved tobacco engineered to be resistant to the herbicide bromoxynil
Bromoxynil
Bromoxynil is a nitrile herbicide, trade names include Brominal, Bromotril, Bronate, Buctril, Certrol B, Litarol, M&B 10064, Merit, Pardner, Sabre, and Torch. It is used for post-emergent control of annual broadleaf weeds. It is especially effective in the control of weeds in cereal, corn,...
, making it the first commercially genetically engineered crop marketed in Europe. In 1995, Bt Potato was approved safe by the Environmental Protection Agency, making it the first pesticide producing crop to be approved in the USA. In 2010, 11 different transgenic crops were grown commercially on 365 million acres (148 million hectares) in 29 countries such as the USA, Brazil, Argentina, India, Canada, China, Paraguay, Pakistan, South Africa and Uraguay.
The U.S. has adopted the technology most widely whereas Europe has very little genetically engineered crops with the exception of Spain where one fifth of maize grown is genetically engineered, and smaller amounts in five other countries. The EU had a 'de facto' ban on the approval of new GM crops, from 1999 until 2004; in a controversial move. GM crops are now regulated by the EU. Developing countries grew 48 per cent of genetically engineered crops in 2010.
Development
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s, of a plant's genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
using genetic engineering
Genetic engineering
Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest...
techniques. Most genetically modified plants are generated by the biolistic method
Gene gun
A gene gun or a biolistic particle delivery system, originally designed for plant transformation, is a device for injecting cells with genetic information. The payload is an elemental particle of a heavy metal coated with plasmid DNA...
(particle gun) or by Agrobacterium tumefaciens
Agrobacterium tumefaciens
Agrobacterium tumefaciens is the causal agent of crown gall disease in over 140 species of dicot. It is a rod shaped, Gram negative soil bacterium...
mediated transformation.
In the biolistic method, DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
is bound to tiny particles of gold or tungsten which are subsequently "shot" into plant tissue or single plant cells under high pressure. The accelerated particles penetrate both the cell wall
Cell wall
The cell wall is the tough, usually flexible but sometimes fairly rigid layer that surrounds some types of cells. It is located outside the cell membrane and provides these cells with structural support and protection, and also acts as a filtering mechanism. A major function of the cell wall is to...
and membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
s. The DNA separates from the metal and is integrated into the plant genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
inside the nucleus
Cell nucleus
In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...
. This method has been applied successfully for many cultivated crops, especially monocots like wheat or maize, for which transformation
Transformation (genetics)
In molecular biology transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material from its surroundings and taken up through the cell membrane. Transformation occurs naturally in some species of bacteria, but it can...
using Agrobacterium tumefaciens has been less successful. The major disadvantage of this procedure is that serious damage can be done to the cellular tissue.
Agrobacteria are natural plant parasites, and their natural ability to transfer genes is used for the development of genetically engineered plants. To create a suitable environment for themselves, these Agrobacteria insert their genes into plant hosts, resulting in a proliferation of plant cells near the soil level (crown gall). The genetic information for tumour growth is encoded on a mobile, circular DNA fragment (plasmid
Plasmid
In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...
). When Agrobacterium infects a plant, it transfers this T-DNA
Ti plasmid
Ti plasmid is a circular plasmid that often, but not always, is a part of the genetic equipment that Agrobacterium tumefaciens and Agrobacterium rhizogenes use to transduce its genetic material to plants. Ti stands for tumor inducing. The Ti plasmid is lost when Agrobacterium is grown above 28°C....
to a random site in the plant genome. When used in genetic engineering the bacterial T-DNA is removed from the bacterial plasmid and replaced with the desired foreign gene. The bacterium is a vector, enabling transportation of foreign genes into plants. This method works especially well for dicotyledon
Dicotyledon
The dicotyledons, also known as dicots, are a group of flowering plants whose seed typically has two embryonic leaves or cotyledons. There are around 199,350 species within this group...
ous plants like potatoes, tomatoes, and tobacco. Agrobacteria infection is less successful in crops like wheat and maize.
Genetically modified plants have been developed commercially to improve shelf life
Shelf life
Shelf life is the length of time that food, drink, medicine, chemicals, and many other perishable items are given before they are considered unsuitable for sale, use, or consumption...
, disease resistance, herbicide resistance and pest resistance. Plants engineered to tolerate non-biological stresses like drought
Drought
A drought is an extended period of months or years when a region notes a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region...
, frost
Frost
Frost is the solid deposition of water vapor from saturated air. It is formed when solid surfaces are cooled to below the dew point of the adjacent air as well as below the freezing point of water. Frost crystals' size differ depending on time and water vapour available. Frost is also usually...
and nitrogen starvation or with increased nutritional value
Biofortification
Biofortification is a method of breeding crops to increase their nutritional value. This can be done either through conventional selective breeding, or through genetic engineering...
(e.g. Golden rice
Golden rice
Golden rice is a variety of Oryza sativa rice produced through genetic engineering to biosynthesize beta-carotene, a precursor of pro-vitamin A in the edible parts of rice...
) were in development in 2011. Future generations of GM plants are intended to be suitable for harsh environments, produce increased amounts of nutrients or even pharmaceutical agents, or are improved for the production of bioenergy and biofuels. Due to high regulatory and research costs, the majority of genetically modified crops in agriculture consist of commodity crops, such as soybean, maize, cotton and rapeseed. However, commercial growing was reported in 2009, of smaller amounts of genetically modified sugar beet, papayas, squash (zucchini), sweet pepper, tomatoes, petunias, carnations, roses and poplars. Recently, some research and development
Research and development
The phrase research and development , according to the Organization for Economic Co-operation and Development, refers to "creative work undertaken on a systematic basis in order to increase the stock of knowledge, including knowledge of man, culture and society, and the use of this stock of...
has been targeted to enhancement of crops that are locally important in developing countries, such as insect-resistant cowpea
Cowpea
The Cowpea is one of several species of the widely cultivated genus Vigna. Four cultivated subspecies are recognised:*Vigna unguiculata subsp. cylindrica Catjang...
for Africa and insect-resistant brinjal
Bt brinjal
The Bt brinjal is a suite of transgenic brinjals created by inserting a crystal protein gene from the soil bacterium Bacillus thuringiensis into the genome of various brinjal cultivars...
(eggplant) for India.
In research tobacco
Tobacco
Tobacco is an agricultural product processed from the leaves of plants in the genus Nicotiana. It can be consumed, used as a pesticide and, in the form of nicotine tartrate, used in some medicines...
and Arabidopsis thaliana
Arabidopsis thaliana
Arabidopsis thaliana is a small flowering plant native to Europe, Asia, and northwestern Africa. A spring annual with a relatively short life cycle, arabidopsis is popular as a model organism in plant biology and genetics...
are the most genetically modified plants, due to well developed transformation methods, easy propagation and well studied genomes. They serve as model organisms for other plant species. Genetically modified plants have also been used for bioremediation
Bioremediation
Bioremediation is the use of microorganism metabolism to remove pollutants. Technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated...
of contaminated soils. Mercury
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
, selenium
Selenium
Selenium is a chemical element with atomic number 34, chemical symbol Se, and an atomic mass of 78.96. It is a nonmetal, whose properties are intermediate between those of adjacent chalcogen elements sulfur and tellurium...
and organic pollutants such as polychlorinated biphenyl
Polychlorinated biphenyl
Polychlorinated biphenyls are a class of organic compounds with 2 to 10 chlorine atoms attached to biphenyl, which is a molecule composed of two benzene rings. The chemical formula for PCBs is C12H10-xClx...
s (PCBs) have been removed from soils by transgenic plants containing gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s for bacterial enzymes.
Types
Transgenesis
thumb|300px|right|A diagram comparing the genetic changes achieved through conventional plant breeding, transgenesis and cisgenesisTransgenesis is the process of introducing an exogenous gene – called a transgene – into a living organism so that the organism will exhibit a new property and transmit...
plants have genes inserted into them that are derived from another species. The inserted genes can come from species within the same kingdom
Kingdom (biology)
In biology, kingdom is a taxonomic rank, which is either the highest rank or in the more recent three-domain system, the rank below domain. Kingdoms are divided into smaller groups called phyla or divisions in botany...
(plant to plant) or between kingdoms (bacteria to plant). In many cases the inserted DNA has to be modified slightly in order to correctly and efficiently express
Gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...
in the host organism. Transgenic plants are used to express proteins like the cry toxins from Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
, herbicide
Herbicide
Herbicides, also commonly known as weedkillers, are pesticides used to kill unwanted plants. Selective herbicides kill specific targets while leaving the desired crop relatively unharmed. Some of these act by interfering with the growth of the weed and are often synthetic "imitations" of plant...
resistant genes and antigens for vaccination
Vaccination
Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...
s
Cisgenic
Cisgenesis
Cisgenesis, sometimes also called Intragenesis, is a product designation for a category of genetically engineered plants. A variety of classification schemes have been proposed , that order genetically modified organisms based on the nature of introduced genotypical changes rather than the process...
plants are made using genes found within the same species or a closely related one, where conventional plant breeding
Plant breeding
Plant breeding is the art and science of changing the genetics of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular...
can occur. Some breeders and scientists argue that cisgenic modification is useful for plants that are difficult to crossbreed
Crossbreed
A crossbreed or crossbred usually refers to an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention to create offspring that share the traits of both parent lineages, or producing...
by conventional means (such as potatoes), and that plants in the cisgenic category should not require the same level of legal regulation as other genetically modified organisms.
In research plants are engineered to help discover the functions of certain genes. One way to do this is to knock out the gene of interest and see what phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...
develops. Another strategy is to attach the gene to a strong promoter and see what happens when it is over expressed. A common technique used to find out where the gene is expressed is to attach it to GUS
GUS reporter system
The GUS reporter system is a reporter gene system, particularly useful in plant molecular biology. Several kinds of GUS reporter gene assay are actually available, depending on the substrate used...
or a similar reporter gene
Reporter gene
In molecular biology, a reporter gene is a gene that researchers attach to a regulatory sequence of another gene of interest in cell culture, animals or plants. Certain genes are chosen as reporters because the characteristics they confer on organisms expressing them are easily identified and...
that allows visualisation of the location.
The first commercialised genetically modified plants (Flavr Savr tomatoes) used RNAi
RNAI
RNAI is a non-coding RNA that is an antisense repressor of the replication of some E. coli plasmids, including ColE1. Plasmid replication is usually initiated by RNAII, which acts as a primer by binding to its template DNA. The complementary RNAI binds RNAII prohibiting it from its initiation role...
technology, where the inserted DNA matched an endogenous
Endogenous
Endogenous substances are those that originate from within an organism, tissue, or cell. Endogenous retroviruses are caused by ancient infections of germ cells in humans, mammals and other vertebrates...
gene already in the plant. When the inserted gene is expressed it can repress the translation
Translation
Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...
of the endogenous protein. Host delivered RNAi systems are being developed, where the plant will express RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
that will interfere with insects, nematodes and other parasites protein synthesis. This may provide a novel way of protecting plants from pests.
Regulation of genetically modified plants
In the USA genetically modified organisms are assessed by the US Department of Agriculture (USDA), the Food and Drug AdministrationFood and Drug Administration
The Food and Drug Administration is an agency of the United States Department of Health and Human Services, one of the United States federal executive departments...
(FDA) and the Environmental protection agency (EPA). The USDA evaluate the plants potential to become weeds, the FDA review plants that could enter or alter the food supply and the EPA regulate the genetically modified plants with pesticide properties. Most developed genetically modified plants are reviewed by at least two of the agencies, with many subject to all three. Final approval can still be denied by individual counties within each state. In 2004, Mendocino County
Mendocino County, California
Mendocino County is a county located on the north coast of the U.S. state of California, north of the greater San Francisco Bay Area and west of the Central Valley. As of the 2010 census, the population was 87,841, up from 86,265 at the 2000 census...
, California became the first and only county to impose a ban on the "Propagation, Cultivation, Raising, and Growing of Genetically Modified Organisms", the measure passing with a 57% majority.
Allergic proteins were detected during testing of a transgenic soybean
Transgenic soybean
Genetically modified soybean is a soybean that has had DNA introduced into it in a way other than the combination of male and female gametes...
inserted with a gene from the Brazil nut
Brazil Nut
The Brazil nut is a South American tree in the family Lecythidaceae, and also the name of the tree's commercially harvested edible seed.- Order :...
. The inserted gene did not translate
Translation (genetics)
In molecular biology and genetics, translation is the third stage of protein biosynthesis . In translation, messenger RNA produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein...
into a known allergen, the allergenic nature of the protein was discovered when tested with serum from people allergic to Brazil nut. Four federal district court
United States district court
The United States district courts are the general trial courts of the United States federal court system. Both civil and criminal cases are filed in the district court, which is a court of law, equity, and admiralty. There is a United States bankruptcy court associated with each United States...
suits
Lawsuit
A lawsuit or "suit in law" is a civil action brought in a court of law in which a plaintiff, a party who claims to have incurred loss as a result of a defendant's actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint...
have been brought against Animal and Plant Health Inspection Service, the agency within USDA that regulates genetically modified plants. Two involved field trials (herbicide-tolerant turfgrass in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
; pharmaceutical-producing corn and sugar in Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...
) and two the deregulation of GM alfalfa
Alfalfa
Alfalfa is a flowering plant in the pea family Fabaceae cultivated as an important forage crop in the US, Canada, Argentina, France, Australia, the Middle East, South Africa, and many other countries. It is known as lucerne in the UK, France, Australia, South Africa and New Zealand, and known as...
. and GM sugar beet. Initially APHIS lost all four cases, with the judges ruling they failed to diligently follow the guidelines set out in the National Environmental Policy Act
National Environmental Policy Act
The National Environmental Policy Act is a United States environmental law that established a U.S. national policy promoting the enhancement of the environment and also established the President's Council on Environmental Quality ....
. In 2010 the US Supreme Court nullified the district court ban on growing GM alfalfa. and in 2011 an appeal court allowed the partial deregulation of GM sugar beet.
The European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
(EU) has possibly the most stringent regulations for genetically modified plants in the world. All genetically modified plants are considered "new food" and subject to extensive, case-by-case, science based food evaluation by the European Food Safety Authority
European Food Safety Authority
The European Food Safety Authority is an agency of the European Union that provides independent scientific advice and communication on existing and emerging risks associated with the food chain, created by European Regulation 178/2002....
(EFSA). The European Commission
European Commission
The European Commission is the executive body of the European Union. The body is responsible for proposing legislation, implementing decisions, upholding the Union's treaties and the general day-to-day running of the Union....
(EC) then draft a proposal that is submitted to the Section on GM Food and Feed of the Standing Committee on the Food Chain and Animal Health, where if accepted it will be adopted by the EC or passed on to the Council of Agricultural Ministers
Council of the European Union
The Council of the European Union is the institution in the legislature of the European Union representing the executives of member states, the other legislative body being the European Parliament. The Council is composed of twenty-seven national ministers...
. There is also a safeguard clause that any Member State
Member state
A member state is a state that is a member of an international organisation.The World Trade Organization has members that are sovereign states and members that are not, thus WTO members are not called member states.- Worldwide :...
can invoke to restrict or prohibit the use or sale of a GM plant within their territory if they have a justifiable reasons to consider that the approved GM plant constitutes a risk to human health or the environment.
Currently (2010) the only genetically modified plants approved for cultivation in Europe are MON810, a Bt expressing maize
Maize
Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...
conferring resistance to the European corn borer
European Corn Borer
The European corn borer , also known as the European high-flyer, is a pest of grain, particularly maize. The insect is native to Europe, originally infesting varieties of millet, including broom corn. The European corn borer was first reported in North America in 1917 in Massachusetts, but was...
and a potato called Amflora
Amflora
Amflora is a genetically modified potato owned by BASF Plant Science. Amflora was approved for industrial applications in the European Union market on 2 March 2010 by the European Commission.-History:...
, approved only for industrial applications. The EC has issued guidelines to allow the co-existence of GM and non-GM crops
Co-existence of genetically modified and conventional crops and derived food and feed
In the context of agriculture and food and feed production, co-existence means using cropping systems with and without genetically modified organisms in parallel. For co-existence to be assured, the separation and the identity of the respective food and feed products must be maintained at all...
through buffer zones (where no GM crops are grown). These are regulated by individual countries and vary from 15 meters in Sweden to 800 meters in Luxembourg. All food (including processed food) or feed
Compound feed
Compound feeds are feedstuffs that are blended from various raw materials and additives. These blends are formulated according to the specific requirements of the target animal...
which contains greater than 0.9% of approved GMOs must be labelled.
Regulation in Australia are provided by the Office of the Gene Technology Regulator
Office of the Gene Technology Regulator
The Office of the Gene Technology Regulator, supports the Gene Technology Regulator, and is a part of the Australian Government Department of Health and Ageing. The Office was established under the Commonwealth Gene Technology Act 2000. This legislation sets forth a nationally consistent regulatory...
and Food Standards Australia New Zealand
Food Standards Australia New Zealand
Food Standards Australia New Zealand is the governmental body responsible for developing food standards for Australia and New Zealand .FSANZ develops food standards after consulting with other government agencies and stakeholders...
. Each state in Australia individually assess the impact of release on markets and trade and can apply further legislation if they deem it necessary. In 2011 genetically modified plants were grown in all states except South Australia and Tasmania, who have extended their moratoriums until 2019 and 2014. Health Canada
Health Canada
Health Canada is the department of the government of Canada with responsibility for national public health.The current Minister of Health is Leona Aglukkaq, a Conservative Member of Parliament appointed to the position by Prime Minister Stephen Harper.-Branches, regions and agencies:Health Canada...
and the Canadian Food Inspection Agency
Canadian Food Inspection Agency
The Canadian Food Inspection Agency is a science based regulatory agency that is dedicated to the safeguarding of food, animals, and plants, which enhance the health and well-being of Canada's people, environment and economy...
are responsible for evaluating the safety and nutritional value of genetically modified plants in Canada.
The Argentine government was one of the first to accept genetically modified plants, with assessment provided by the National Agricultural Biotechnology Advisory Committee (for environmental impact), the National Service of Health and Agrifood Quality (for food safety) and the National Agribusiness Direction (for theeffect on trade) The final decision is made by the Secretariat of Agriculture, Livestock, Fishery and Food. In Brazil the 27 member National Biosafety Technical Commission is responsible for assessing environmental impact, food safety and provides guidelines for transport, importation and field experiments. In 2005, the Mexican senate passed a law allowing planting and selling of genetically modified crops.
Genetically modified crops in China go through three phases of field trials (pilot field testing, environmental release testing, and preproduction testing) before they are submitted to the Office of Agricultural Genetic Engineering Biosafety Administration (OAGEBA) for assessment. The 75 member National Biosafety Committee evaluates all applications, although OAGEBA has the final decision. The cost of regulation enforcement in India is generally higher than China, while the enforcement of regulations has proved more effective in China. The National Assembly of Burkina Faso passed a biosafety law in early 2006, which established a National Biosafety Agency that would regulate GM products with the advise of various governmental and non-governmental advisory committees.
Biosafety
Genetically modified plants can spread the trans gene to other plants or – theoretically – even to bacteria. Depending on the transgene, this may pose a threat to the environment by changing the composition of the local ecosystem.Therefore, in most countries environmental studies are required prior to the approval of a GM plant for commercial purposes, and a monitoring plan must be presented to identify potential effects which have not been anticipated prior to the approval.
Little research has been conducted on human and animal health. However, in most countries every GM plant is tested in feeding trials to prove its safety, before it is approved for use and marketing. The project GMO-Safety collects and presents biosafety research on GMOs with more in-depth information on this topic.http://www.gmo-safety.eu
The potential impact on nearby ecosystems is one of the greatest concerns associated with transgenic plants.
Transgenes have the potential for significant ecological impact if the plants can increase in frequency and persist in natural populations. These concerns are similar to those surrounding conventionally bred plant breeds. Several risk factors should be considered:
- Can the transgenic plant pass its genes to a local wild species, and are the offspring also fertile?
- Does the introduction of the transgene confer a selective advantage to the plant or to hybrids in the wild?
Many domesticated plants can mate and hybridise with wild relatives when they are grown in proximity, and whatever genes the cultivated plant had can then be passed to the hybrid. This applies equally to transgenic plants and conventionally bred plants, as in either case there are advantageous genes that may have negative consequences to an ecosystem upon release. This is normally not a significant concern, despite fears over 'mutant superweeds' overgrowing local wildlife: although hybrid plants are far from uncommon, in most cases these hybrids are not fertile due to polyploidy
Polyploidy
Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...
, and will not multiply or persist long after the original domestic plant is removed from the environment. However, this does not negate the possibility of a negative impact.
In some cases, the pollen from a domestic plant may travel many miles on the wind before fertilising another plant. This can make it difficult to assess the potential harm of crossbreeding; many of the relevant hybrids are far away from the test site. Among the solutions under study for this concern are systems designed to prevent transfer of transgenes, such as Terminator Technology
Terminator Technology
Genetic use restriction technology , colloquially known as terminator technology, is the name given to proposed methods for restricting the use of genetically modified plants by causing second generation seeds to be sterile...
, and the genetic transformation of the chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
only, so that only the seed of the transgenic plant would bear the transgene. With regard to the former, there is some controversy that the technologies may be inequitable and might force dependence upon producers for valid seed in the case of poor farmers, whereas the latter has no such concern but has technical constraints that still need to be overcome. Solutions are being developed by EU funded research programmes such as Co-Extra
Co-Extra
Co-Extra is an EU-funded research programme on co-existence and traceability of genetically modified crops and their edible derivatives. It has been granted €13.5 million under the Sixth Framework Programme of the European Union, and is conducted by more than 200 scientists in 52 organisations in...
and Transcontainer.
There are at least three possible avenues of hybridization leading to escape of a transgene:
- Hybridization with non-transgenic crop plants of the same species and variety.
- Hybridization with wild plants of the same species.
- Hybridization with wild plants of closely related species, usually of the same genus.
However, there are a number of factors which must be present for hybrids to be created.
- The transgenic plants must be close enough to the wild species for the pollen to reach the wild plants.
- The wild and transgenic plants must flower at the same time.
- The wild and transgenic plants must be genetically compatible.
In order to persist, these hybrid offspring:
- Must be viable, and fertile.
- Must carry the transgene.
Studies suggest that a possible escape route for transgenic plants will be through hybridization with wild plants of related species.
- It is known that some crop plants have been found to hybridize with wild counterparts.
- It is understood, as a basic part of population genetics, that the spread of a transgene in a wild population will be directly related to the fitnessFitness (biology)Fitness is a central idea in evolutionary theory. It can be defined either with respect to a genotype or to a phenotype in a given environment...
effects of the gene in addition to the rate of influx of the geneGeneA gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
to the populationPopulationA population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
. Advantageous genes will spread rapidly, neutral genes will spread with genetic driftGenetic driftGenetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...
, and disadvantageous genes will only spread if there is a constant influx. - The ecological effects of transgenes are not known, but it is generally accepted that only genes which improve fitness in relation to abiotic factors would give hybrid plants sufficient advantages to become weedWeedA weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...
y or invasiveInvasive species"Invasive species", or invasive exotics, is a nomenclature term and categorization phrase used for flora and fauna, and for specific restoration-preservation processes in native habitats, with several definitions....
. Abiotic factors are parts of the ecosystem which are not alive, such as climate, salt and mineral content, and temperature. Genes improving fitness in relation to biotic factors could disturb the (sometimes fragile) balance of an ecosystem. For instance, a wild plant receiving a pest resistance gene from a transgenic plant might become resistant to one of its natural pests, say, a beetle. This could allow the plant to increase in frequency, while at the same time animals higher up in the food chain, which are at least partly dependent on that beetle as food source, might decrease in abundance. However, the exact consequences of a transgene with a selective advantage in the natural environment are almost impossible to predict reliably.
It is also important to refer to the demanding actions that government of developing countries had been building up among the last decades.
Agricultural impact of transgenic plants
Outcrossing of transgenic plants not only poses potential environmental risks, it may also trouble farmers and food producers. Many countries have different legislations for transgenic and conventional plants as well as the derived food and feed, and consumers demand the freedom of choice to buy GM-derived or conventional products. Therefore, farmers and producers must separate both production chains. This requires coexistenceCo-existence of genetically modified and conventional crops and derived food and feed
In the context of agriculture and food and feed production, co-existence means using cropping systems with and without genetically modified organisms in parallel. For co-existence to be assured, the separation and the identity of the respective food and feed products must be maintained at all...
measures on the field level as well as traceability
Traceability of genetically modified organisms
The traceability of genetically modified organisms describes a system that ensures the forwarding of the identity of a GMO from its production to its final buyer. Traceability is an essential prerequisite for the co-existence of GM and non-GM foods, and for the freedom of choice for consumers.-Why...
measures throughout the whole food and feed processing chain. Research projects such as Co-Extra
Co-Extra
Co-Extra is an EU-funded research programme on co-existence and traceability of genetically modified crops and their edible derivatives. It has been granted €13.5 million under the Sixth Framework Programme of the European Union, and is conducted by more than 200 scientists in 52 organisations in...
, SIGMEA and Transcontainer investigate how farmers can avoid outcrossing and mixing of transgenic and non-transgenic crops, and how processors can ensure and verify the separation of both production chains.
Coexistence and traceability
In many countries, and especially in the European UnionEuropean Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
, consumers demand the choice between foods derived from GM plants and conventionally or organically produced plants. This requires a labelling system as well as the reliable separation of GM and non-GM crops at field level and throughout the whole production chain.
Research has demonstrated, that coexistence
Co-existence of genetically modified and conventional crops and derived food and feed
In the context of agriculture and food and feed production, co-existence means using cropping systems with and without genetically modified organisms in parallel. For co-existence to be assured, the separation and the identity of the respective food and feed products must be maintained at all...
can be realised by several agricultural measures, such as isolation distances
Isolation distance for genetically modified plants
Isolation distances are used in regions where genetically modified and conventional or organic crops are grown in co-existence. When different cropping systems are grown in proximity to each other, the "isolation distance" between fields refers to the area separating them, on which genetically...
or biological containment
Biological containment
Biological containment describes measures aimed at preventing genetically modified organisms and their transgenes from spreading into the environment ....
strategies.http://www.coextra.eu
For traceability
Traceability of genetically modified organisms
The traceability of genetically modified organisms describes a system that ensures the forwarding of the identity of a GMO from its production to its final buyer. Traceability is an essential prerequisite for the co-existence of GM and non-GM foods, and for the freedom of choice for consumers.-Why...
, the OECD has introduced a "unique identifier" which is given to any GMO when it is approved. This unique identifier must be forwarded at every stage of processing.
Many countries have established labelling regulations and guidelines on coexistence and traceability. Research projects like Co-Extra
Co-Extra
Co-Extra is an EU-funded research programme on co-existence and traceability of genetically modified crops and their edible derivatives. It has been granted €13.5 million under the Sixth Framework Programme of the European Union, and is conducted by more than 200 scientists in 52 organisations in...
, SIGMEA and Transcontainer are aimed at investigating improved methods for ensuring coexistence and providing stakeholders the tools required for the implementation of coexistence and traceability.
See also
- Developing countryDeveloping countryA developing country, also known as a less-developed country, is a nation with a low level of material well-being. Since no single definition of the term developing country is recognized internationally, the levels of development may vary widely within so-called developing countries...
- Food and Agriculture OrganizationFood and Agriculture OrganizationThe Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...
- Food securityFood securityFood security refers to the availability of food and one's access to it. A household is considered food-secure when its occupants do not live in hunger or fear of starvation. According to the World Resources Institute, global per capita food production has been increasing substantially for the past...
- Foreign Agricultural ServiceForeign Agricultural ServiceThe Foreign Agricultural Service is the foreign affairs agency with primary responsibility for the United States Department of Agriculture's overseas programs—market development, international trade agreements and negotiations, and the collection of statistics and market information...
- Genetic pollutionGenetic pollutionGenetic pollution is a controversial term for uncontrolled gene flow into wild populations. This gene flow is undesirable according to some environmentalists and conservationists, including groups such as Greenpeace, TRAFFIC, and GeneWatch UK.-Usage:...
- HungerHungerHunger is the most commonly used term to describe the social condition of people who frequently experience the physical sensation of desiring food.-Malnutrition, famine, starvation:...
- International developmentInternational developmentInternational development or global development is a concept that lacks a universally accepted definition, but it is most used in a holistic and multi-disciplinary context of human development — the development of greater quality of life for humans...
- International Fund for Agricultural DevelopmentInternational Fund for Agricultural DevelopmentThe International Fund for Agricultural Development , a specialized agency of the United Nations, was established as an international financial institution in 1977 as one of the major outcomes of the 1974 World Food Conference. IFAD is dedicated to eradicating rural poverty in developing countries...
- Substantial equivalenceSubstantial equivalenceSubstantial equivalence is a concept, developed by OECD in 1991, that maintains that a novel food should be considered the same as and as safe as a conventional food if it demonstrates the same characteristics and composition as the conventional food. Substantial equivalence is important from a...
- United States Department of AgricultureUnited States Department of AgricultureThe United States Department of Agriculture is the United States federal executive department responsible for developing and executing U.S. federal government policy on farming, agriculture, and food...
External links
- GMO-Compass: News and backgrounds on GM plants, including a database of approvals in the EU
- GMO-Safety: Research on biosafety
- Co-Extra: Research on co-existence and traceability
- SIGMEA: Research on the safe introduction of GMOs in European agriculture
- Transcontainer: Research on biological containment of transgenes
- OECD BioTrack Product Database of Unique Identifiers