Overview of Genetically Engineered Crops

Education Services / L’équipe des services d’éducation
10 April 2014

This is a background resource for Agriculture & Biotech
  Overview of GE Crops (download pdf)

Selected GE Crops Approved in Canada, With Trait Details 1
(crops currently grown indicated with an asterisk*, others are approved for consumption by Health Canada, but not grown in Canada)

Trait

How Transgene Causes Trait

Crops With Transgene

Glyphosate herbicide tolerance

(Glyphosate is the active ingredient in the herbicide RoundUp®, so glyphosate-tolerant crops are sometimes called “RoundUp®-Ready”.)

Glyphosate-containing herbicides kill plants by blocking an enzyme required for aromatic amino acid synthesis(EPSPS). A glyphosate-resistant version of EPSPS found in a soil bacterium was transferred to crop plants. Abacterial enzyme that degrades glyphosate has also been co-transferred for some crop lines.

soybeans*, canola*, corn*, sugarbeet*, alfalfa

Glufosinate herbicide tolerance

Glufosinate-containing herbicides kill plants by blocking an enzyme required for nitrogen metabolism and ammonium detoxification. An enzyme that breaks down glufosinate, found in a soil bacterium, was transferred to crop plants.

canola*, corn*, soybeans*

Insect resistance

Beetles (coleopterans) and moth and butterfly caterpillars (lepidopteron) damage many crops by eating them. Insecticidal proteins found in the soil bacterium Bacillus thuringiensis (Bt) were transferred to crop plants. These proteins damage cells in the digestive tract, specific to coleopterans and/or lepidopteron, and kill the insects. Engineered crops are often called “Bt-crops”.

corn*, potato

Virus resistance

Viral pathogens like cucumber mosaic virus, zucchini yellow mosaic virus and potato virus Y cause disease in susceptible crops. Though the mechanism is not completely understood, engineering a crop plant to produce viral proteins confers resistance to infection. Crops produce only one viral protein, which does not cause disease itself. In 1998, Hawaiian papaya cultivation was saved from the papaya ringspot virus by the same approach.4

squash, potato

Drought-tolerant corn

Plants, animals and bacteria use special proteins that bind to RNA (ribonucleic acid) molecules when cells face biologically stressful conditions, such as drought for plants. This helps the cells, and therefore the whole organism, survive the stress. One of these special proteins, called cold-shock protein B, was transferred from a type of soil bacterium to corn plants to improve their survival during drought conditions.

corn



Selected GE Crops Grown Globally2

Cotton: herbicide-tolerance and insect-tolerance (Bt-cotton)

Rice: herbicide-tolerance and insect-tolerance

Soybeans: Modified oils (discussed in detail in Soybean Backgrounder)

Melon: delayed ripening

Plum: virus resistance

Wheat: herbicide-tolerance

Flax: herbicide-tolerance

Canola: herbicide-tolerance and modified oils

Notes : Globally, herbicide-tolerant soybeans were the most grown GE-crop in 2011(47% of all GE crop area).Different traits are sometimes combined in the same crop line, called “stacked traits”. Stacked traits corn was 23% of GE crop area in 2011. Bt-cotton came in third, at 11% of global GE crop area.3

Selected GE Crops in Development5

Vitamin A-enriched rice (“Golden Rice”) – increased levels of Vitamin A precursors (carotenoids) to combat Vitamin A deficiency in developing countries.

Flood-tolerant rice – important for South and SoutheastAsia

Fungus-resistant wheat – to combat new strains of stem rust fungus, a serious wheat pathogen



References

1 http://www.hc-sc.gc.ca/fn-an/gmf-agm/appro/index-eng.php,
2 http://isaaa.org/resources/publications/pocketk/2/default.asp,
3 http://isaaa.org/resources/publications/pocketk/16/default.asp,
4 http://www.agbioforum.org/v7n12/v7n12a07-gonsalves.htm,
5 http://www.genetics.org/content/188/1/11.full

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