Genetically modified wheat

Genetically modified wheat is wheat that has been genetically engineered by the direct manipulation of its genome using biotechnology. As of 2015, no GM wheat is grown commercially, although many field tests have been conducted.

Background

Wheat is a natural hybrid derived from interspecies breeding. It is theorized that wheat's ancestors (Triticum monococcum, Aegilops speltoides, and Aegilops tauschii, all diploid grasses) hybridized naturally over millennia somewhere in West Asia, to create natural polyploid hybrids, the best known of which are common wheat and durum wheat.[1]

Wheat (Triticum spp.) is an important domesticated grass used worldwide for food. Its evolution has been influenced by human intervention since the dawn of agriculture.[2]

Interspecies transfer of genes continued to occur in farmers fields during the shift from the Paleolithic diet to the diet adopted by humans following the Neolithic Revolution, or first green revolution.[3] During the transition from a hunter-gatherer social structure to more agrarian societies, humans began to cultivate wheat and further transform it for their needs. Thus, the social and cultural roots of humans and the development of wheat have intertwined since before recorded history.

This process resulted in various wheat species that are grown for specific purposes and climates. In 1873 Wilson [4] cross-pollinated rye and wheat to create triticale. Further transformations using cytogenic hybridization techniques enabled Norman Borlaug, father of the second Green Revolution,[3] to develop wheat species (the semidwarf varieties) that would grow in harsh environments.

Recombinant DNA techniques were developed in the 1980s, work began on creating the first transgenic wheat, coincident with the third Green Revolution.[3] Of the three most important cereals in the world (corn, rice and wheat), wheat was the last to be transformed by transgenic, biolistic methods in 1992, and by Agrobacterium methods in 1997.[5][6] Unlike corn and rice, its widespread use in the human diet has faced cultural resistance.[7][8]

Field trials and approvals

As of 2013, 34 field trials of GM wheat have taken place in Europe and 419 have taken place in the US.[9] Modifications tested include those to create resistance to herbicides, create resistance to insects[10][11][12] and to fungal pathogens (especially fusarium) and viruses,[13][14] tolerance to drought and resistance to salinity[15] and heat,[16] increased[17][18] and decreased[19] content of glutenin, improved nutrition (higher protein content, increased heat stability of the enzyme phytase, increased content of water-soluble dietary fiber, increased lysine content),[20][21] improved qualities for use as biofuel feedstock, production of drugs via pharming and yield increases.[9][22][23][24][25][26]

As of 2015, no GM wheat had been approved for release anywhere in the world.[27]

Monsanto's MON 71800

The transgenic wheat that was furthest developed was Monsanto's MON 71800, which is glyphosate-resistant via a CP4/maize EPSPS gene.[28] Monsanto received approval from the FDA for its use in food, but withdrew its EPA application in 2004, so the product was never marketed. It also received approval for use as food in Colombia.[29]

Studies conducted by Monsanto showed that its nutritional components are equivalent to nontransgenic commercially available wheat,[30] and animal studies that have used MON 71800 for feed have confirmed this.[31] Environmental Risk assessments have been conducted by Monsanto,[32] and government regulatory agencies have approved its use in food;[33]

However, farmers were worried about the potential loss of markets in Europe and Asia due to public refusal of the end-product,[34][35] so Monsanto withdrew its EPA application for Roundup-Ready Wheat.[36]

In 2010 Monsanto's partner in India, Mahyco, announced that it planned to seek approval to market GM wheat in India in the next three to five years.[37]

Escape of GM wheat seed

In 1999 scientists in Thailand claimed they discovered glyphosate-resistant wheat in a grain shipment from the Pacific Northwest of the United States, even though transgenic wheat had never been approved for sale and was only ever grown in test plots. No one could explain how the transgenic wheat got into the food supply.[38]

In May 2013 a strain of genetically-engineered glyphosate-resistant wheat was found on a farm in Oregon. Extensive testing confirmed the wheat as a variety – MON71800.[39] The wheat had been developed by Monsanto but never been approved or marketed after the company had tested it between 1998 and 2005. The unexplained presence of this type of wheat presents a problem to wheat growers when buyers demand GMO-free wheat.[40] Japan subsequently suspended import of soft white wheat from the United States.[41] A Kansas farmer sued Monsanto over the release, saying it had caused the price of wheat grown in the US to fall.[42] Monsanto suggested that the presence of this wheat was likely an act of sabotage.[43] On Jun 14, 2013, the USDA announced: "As of today, USDA has neither found nor been informed of anything that would indicate that this incident amounts to more than a single isolated incident in a single field on a single farm. All information collected so far shows no indication of the presence of GE wheat in commerce."[44] As of August 30, 2013, while the source of the GM wheat remained unknown, Japan, South Korea and Taiwan had all resumed placing orders, and the disruption of the export market was minimal.[45]

The investigation was closed in 2014 after the APHIS had exhausted all leads but had not found any evidence that the wheat had entered commercial supply.

Regulation

The regulation of genetic engineering concerns the approaches taken by governments to assess and manage the risks associated with the development and release of genetically modified crops. There are differences in the regulation of GM crops between countries, with some of the most marked differences occurring between the USA and Europe. Regulation varies in a given country depending on the intended use of the products of the genetic engineering. For example, a crop not intended for food use is generally not reviewed by authorities responsible for food safety.

Controversy

Critics have objected to GM crops per se on several grounds, including ecological concerns, and economic concerns raised by the fact these organisms are subject to intellectual property law. GM crops also are involved in controversies over GM food with respect to whether food produced from GM crops is safe and whether GM crops are needed to address the world's food needs. See the genetically modified food controversies article for discussion of issues about GM crops and GM food. These controversies have led to litigation, international trade disputes, and protests, and to restrictive legislation in a limited number of countries.

References

  1. Wrigley, Corke & Walker 2004, p. 330
  2. Wrigley, Corke & Walker 2004, p. 323
  3. 1 2 3 Nelson 2001, p. 144
  4. Wilson 1876, p. 286
  5. Jones & Shewry 2009, table on p.4
  6. Plant Genetics/Genomics: Crops and Models Vol. 7: Genetics and Genomics of the Triticeae. Feuillet, C. and Muehlbauer, G. (eds.) p. 372
  7. Jones & Shewry 2009, p. 273
  8. "Wheat at Forefront of Battle Over Genetically Modified Organisms". Theitem.com. Retrieved 13 January 2012.
  9. 1 2 Staff, GMO Compass. Last updated June 2010. GM Wheat
  10. Avise 2004, p. 47
  11. "Production of Transgenic Wheat (Triticum aestivum) Plants with Insect-resisting gene via Three Optimized Genetic Transformation Systems". Latest-science-articles.com. Retrieved 13 January 2012.
  12. Picket, John (2 May 2012) Respect the need to experiment with GM crops New scientist, Retrieved 2 May 2012
  13. Heller 2003, p. 41
  14. "You reap what you sow: field trial with genetically modified wheat". Agroscope.admin.ch. 3 February 2009. Retrieved 13 January 2012.
  15. Kempken, F. and Jun, C. (eds.).Genetic Modification of Plants: Agriculture, Horticulture and Forestry.(2010) p. 291
  16. Lal et al. 2004, p. 13
  17. Hamaker 2008, p. 466
  18. Heller 2003, p. 49
  19. Norero, Daniel (28 August 2015). "Gluten-free GM wheat can help celiac patients". Biology Fortified. Retrieved 2015-09-01.
  20. Avise 2004, p. 65
  21. Allan K. Ayella; Harold N. Trick; Weiqun Wang. "Enhancing lignan biosynthesis by over-expressing pinoresinol lariciresinol reductase in transgenic wheat". 51 (12). Molecular Nutrition & Food Research: 1518–1526.
  22. Jansson, J., Elsas, J., and Bailey, M. Tracking Genetically-Engineered Microorganisms. (2000) pp. 94–95
  23. Hamaker 2008, p. 102
  24. Heller 2003, p. 47
  25. Bailey, Ronald. "Anti-Biotech Superstition Being Beaten Back in Europe?" Reason, 21 July 2011.
  26. Avise 2004, p. 62
  27. Staff, USDA Economic Research Service. Last updated: January 24, 2013 Wheat Background
  28. Heller 2006, p. 36
  29. "Biosafety Clearing-House Living Modified Organism identity database". Bch.cbd.int. Retrieved 13 January 2012.
  30. Obert J.C., et al. (2004) "The composition of grain and forage from glyphosate tolerant wheat MON 71800 is equivalent to that of conventional wheat (Triticum aestivum L.)." J.Agric Food Chem. 2004 Mar 10:53(5):1375-84
  31. Kan, C. A. and Hartnell, G. F. (2004) "Evaluation of broiler performance when fed Roundup-Ready wheat (event MON 71800), control, and commercial wheat varieties" Poultry Science, Vol 83, Issue 8, 1325–1334
  32. "The Center for Environmental Risk Assessment database". Cera-gmc.org. 30 June 2005. Retrieved 13 January 2012.
  33. "U.S. Food and Drug Administration Biotechnology Consultation Note to the File BNF No. 000080". Cera-gmc.org. 18 January 2001. Retrieved 13 January 2012.
  34. "Network of Concerned Farmers, Submission on APPLICATION A524 FOOD DERIVED FROM HERBICIDE-TOLERANT WHEAT MON 71800". Non-gm-farmers.com. Retrieved 13 January 2012.
  35. Michael Hopkin for Nature News. 11 May 2004 Monsanto scrubs transgenic wheat: Farmers' fears spell doom for project worth millions
  36. "WestBred Sale Could Change Wheat Industry". Foodmanufacturing.com. 25 September 2009. Retrieved 13 January 2012.
  37. Thomas Kutty Abraham (6 August 2010). "Monsanto-backed Mahyco Plans India's First GM Wheat". Bloomberg Businessweek. Archived from the original on May 21, 2011. Retrieved 3 October 2010.
  38. Hannelore Sudermann for the Spokesman Review (Spokane, WA). October 14, 1999 Genetically Altered Wheat Flagged – Thailand Detects Shipment Not Cleared for Commercial Sales
  39. Staff (June 14, 2013). "Genetically modified wheat investigation". Oregon Department of Agriculture. Retrieved 2013-06-24.
  40. Reuters (2013-05-29). "Unapproved Monsanto GMO Wheat Found in Oregon". CNBC. Retrieved 2013-05-30.
  41. Allison M (June 1, 2013). "Japan's wheat-import suspension worries state growers". Seattle Times. Retrieved June 2013. Check date values in: |access-date= (help)
  42. Hegeman, Roxana (2013-06-04). "Monsanto sued over genetically modified wheat". USA Today. AP. Retrieved 2013-12-24.
  43. Ian Berry (June 21, 2013). "Monsanto Says Sabotage Is Likely in Wheat Case". Wall Street Journal. Retrieved June 23, 2013.
  44. Staff, Food Safety News. June 17, 2013. GMO Wheat Found in Oregon Was Isolated Incident, Says USDA
  45. Associated Press. August 30, 2013. Source of GMO wheat in Oregon remains mystery

Bibliography

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