![Cotton_boll_nearly_ready_for_harvest](https://upload.wikimedia.org/wikipedia/commons/c/c5/Cotton_boll_nearly_ready_for_harvest.jpg)
Genetic use restriction technology (GURT), also known as terminator technology or suicide seeds, is the name given to proposed methods for restricting the use of
genetically modified crops
Genetically modified crops (GM 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 ...
by activating (or deactivating) some genes only in response to certain stimuli, especially to cause second generation seeds to be infertile.
The development and application of GURTs is primarily an attempt by private sector agricultural breeders to increase the extent of protection on their innovations.
The technology was originally developed under a cooperative research and development agreement between the
Agricultural Research Service
The Agricultural Research Service (ARS) is the principal in-house research agency of the United States Department of Agriculture (USDA). ARS is one of four agencies in USDA's Research, Education and Economics mission area. ARS is charged with ext ...
of the
United States Department of Agriculture
The United States Department of Agriculture (USDA) is the United States federal executive departments, federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, ...
and
Delta and Pine Land company in the 1990s and is not yet commercially available.
[ (Position Paper Supporting V-GURT development)]
GURT was first reported on by the Subsidiary Body on Scientific, Technical and Technological Advice (SBSTTA) to the UN
Convention on Biological Diversity
The Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention, is a multilateral treaty. The Convention has three main goals: the conservation of biological diversity (or biodiversity); the sustainable use of its ...
and discussed during the 8th Conference of the Parties to the United Nations
Convention on Biological Diversity
The Convention on Biological Diversity (CBD), known informally as the Biodiversity Convention, is a multilateral treaty. The Convention has three main goals: the conservation of biological diversity (or biodiversity); the sustainable use of its ...
in
Curitiba
Curitiba () is the capital and largest city in the state of Paraná (state), Paraná in Brazil. The city's population was 1,948,626 , making it the List of cities in Brazil by population, eighth most populous city in Brazil and the largest in ...
, Brazil, March 20–31, 2006.
Process
![GURT process diagram](https://upload.wikimedia.org/wikipedia/commons/7/77/GURT_process_diagram.png)
Because of the continued development of the technology and the continued protection of patents that develop it, many descriptions of GURT differ from others. Even so, the basic description of many GURTs are similar.
The process is typically composed of four genetic components: a target gene, a promoter, a trait switch, and a genetic switch, sometimes with slightly different names in different papers.
For example, a typical GURT works similarly to as follows: a plant with GURT technology has a ''target
gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
'' in its
DNA that expresses when activated by a ''promoter gene''. However, it is separated from the gene by a ''blocker sequence'' that prevents the promoter from accessing the target. When the plant receives a given external input, a ''genetic switch'' in the plant takes the input, amplifies it, and converts it into a biological signal. When a ''trait switch'' receives the amplified signal, it creates an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
that cuts the blocker sequence out. Finally, with the blocker sequence eliminated, the promoter gene is able to make the target gene to express itself in the plant.
[Yi Sang Reginald J. Millwood C. Neal Stewart Jr]
"Gene use restriction technologies for transgenic plant bioconfinement"
04 June 2013
In other versions of the process, an operator must bind to the trait switch in order for it to make the enzymes that cut out the blocker sequence. However, there are repressors that bind to the trait switch and prevent it from doing so. In this case, when the external input is applied, the repressors bond to it instead of the trait switch, allowing for the enzymes to be created that cut the blocker sequence, and the trait is expressed.
[Luca Lombardo]
"Genetic use restriction technologies: a review"
17 July 2014
Other variations of GURT range widely, including systems such as letting the genetic switch directly affect the blocker sequence and bypass the need for a trait switch.
Variants
There are conceptually two types of GURT.
[Jefferson RA et al]
Genetic Use Restriction Technologies
Technical Assessment of the Set of New Technologies which Sterilize or Reduce the Agronomic Value of Second Generation Seed, as Exemplified by U.S. Patent No. 5,723,765, and WO 94/03619. Expert paper, prepared for the Secretariat on 30 April 1999 V-GURTs were developed first, with patents ranging throughout the 1990s, while T-GURTS were developed later and are sometimes considered the second generation of V-GURTS.
The differences between the two types of GURT mainly rely on what the target gene does when it is activated.
Variety specific
Variety specific genetic use restriction technologies (V-GURT) produce sterile seeds, so the seed from the crop could not be used as seeds, but only for sale as food or fodder.
When a plant reaches a given reproductive stage in its cycle, the process of activating the target gene begins. In V-GURTs, the target gene is known as a disrupter gene, and is usually a
cytotoxin
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa'').
Cell physiology
Treating c ...
that degrades the DNA or
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
of the plant. This results in a non-functioning seed that cannot grow into a plant.
V-GURTs would not have an immediate impact on the large number of primarily western farmers who use
hybrid seed In agriculture and gardening, hybrid seed is produced by cross-pollinated plants. Hybrid seed production is predominant in modern agriculture and home gardening. It is one of the main contributors to the dramatic rise in agricultural output during ...
s, as they do not produce their own planting seeds, and instead buy specialized hybrid seeds from seed production companies. However, currently around 80 percent of farmers in both Brazil and Pakistan grow crops based on saved seeds from previous harvests.
[Haider Rizvi]
"BIODIVERSITY: Don't Sell "Suicide Seeds", Activists Warn"
Inter Press Service News Agency, March 21, 2006 Consequentially, resistance to the introduction of GURT technology into developing countries is strong.
The technology is restricted at the plant variety level, hence the term V-GURT.
Trait specific
Trait specific genetic use restriction technologies (T-GURT) are a second type of GURT that would modify a crop in such a way that the genetic enhancement engineered into the crop does not function until the plant is treated with a specific chemical.
[ Retrieved October 17, 2018] The chemical acts as the external input, activating the target gene. One difference in T-GURTs is the possibility that the gene could be toggled on and off with different chemical inputs, resulting in the same toggling on or off an associated trait. With T-GURTs, seeds could possibly be saved for planting with a condition that the new plants do not get any enhanced traits unless the external input is added. The technology is restricted at the trait level, hence the term T-GURT.
Potential uses
There are several proposed uses for GURTs that could benefit both businesses and farms.
Non-viable seeds produced on V-GURT plants may reduce the propagation of
volunteer plants. Volunteer plants can become an economic problem for larger-scale mechanized farming systems that incorporate
crop rotation
Crop rotation is the practice of growing a series of different types of crops in the same area across a sequence of growing seasons. It reduces reliance on one set of nutrients, pest and weed pressure, and the probability of developing resistant ...
.
Furthermore, under warm, wet
harvest
Harvesting is the process of gathering a ripe crop from the fields. Reaping is the cutting of grain or pulse for harvest, typically using a scythe, sickle, or reaper. On smaller farms with minimal mechanization, harvesting is the most labor-i ...
conditions non V-GURT grain can sprout, lowering the quality of grain produced. It is likely that this problem would not occur with the use of V-GURT grain varieties.
Use of V-GURT technology could also prevent escape of
transgene
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 ...
s into wild relatives and help lessen impacts on
biodiversity
Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...
. Crops modified to produce non-food products could be armed with GURT technology to prevent accidental transmission of these traits into crops meant for foods.
One of the original proposed uses for GURTs was to use them as alternatives to keep farmers from reusing patented seeds in the case that typical biological patents do not exist or are not enforced.
The use of T-GURTs by companies has been proposed to allow for the selling of a traditional seed that gets special functions only when sprayed with a certain activator chemical sold by the company.
Another proposed use is in synthetic biology, where a restricted activator chemical must be added fermentation medium to produce a desired output chemical.
Controversy
As of 2006, GURT seeds have not been commercialized anywhere in the world due to opposition from farmers, consumers,
indigenous peoples
Indigenous peoples are culturally distinct ethnic groups whose members are directly descended from the earliest known inhabitants of a particular geographic region and, to some extent, maintain the language and culture of those original people ...
,
NGOs
A non-governmental organization (NGO) or non-governmental organisation (see spelling differences) is an organization that generally is formed independent from government. They are typically nonprofit entities, and many of them are active in h ...
, and some governments. Using the technology, companies that manufacture genetic use restriction technologies could potentially be able to make much more revenue because the seeds sold would not be able to be resown. Another concern is that farmers purchasing the seeds would be greatly impacted, given they would have to buy new seeds every year. It has been argued that this would result in higher prices in food. GURT seeds are worried to cause a significant decrease in biodiversity and threaten native species of plants. However, proponents of the technology dispute these claims, making the cases that because non-GMO hybrid plants are used in the same way and GURT seeds could help farmers deal with cross pollination, the benefits outweigh the potential negatives.
In 2000, the United Nations Convention on Biological Diversity recommended a ''de facto''
moratorium on field-testing and commercial sale of terminator seeds; the moratorium was re-affirmed and the language strengthened in March 2006, at the COP8 meeting of the UNCBD.
Specifically, the moratorium recommended that, due to a lack of research on the technology's potential risks, no field testing of GURTs nor products using them should be allowed until there was a sufficiently justified reason to do so.
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
and
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
have passed national laws to prohibit the technology.
See also
*
Cartagena Protocol on Biosafety
The Cartagena Protocol on Biosafety to the Convention on Biological Diversity is an international agreement on biosafety as a supplement to the Convention on Biological Diversity (CBD) effective since 2003. The Biosafety Protocol seeks to prote ...
* ''
Diamond v. Chakrabarty
''Diamond v. Chakrabarty'', 447 U.S. 303 (1980), was a United States Supreme Court case dealing with whether living organisms can be patented. Writing for a five-justice majority, Chief Justice Warren E. Burger held that human-made bacteria could ...
''
*
Digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures (TPM) such as access control technologies can restrict the use of proprietary hardware and copyrighted works. ...
*
Genetic pollution
Genetic pollution is a controversial term for uncontrolled gene flow into wild populations. It is defined as "the dispersal of contaminated altered genes from genetically engineered organisms to natural organisms, esp. by cross-pollination", but ...
*
Genetically modified organism
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 ...
*
Seed saving
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosperm pl ...
*
Transgenic maize
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 trait ...
References
External links
- UNEP/CBD/COP/5/2 - 11 November 1999- Mention of genetic use restriction tech on pages 22, 42
UN Convention on Biological Diversity - Cartagena Protocol on Biosafety
{{DEFAULTSORT:Genetic Use Restriction Technology
Genetic engineering
Genetics techniques