How GM Plants Conquered the World

What are GMOs?

Organisms that are genetically modified have undergone alterations to their genetic material in a process known as genetic engineering. These alterations result in the organism expressing a trait or traits that would not naturally occur in that organism. GMOs currently exist in bacteria, animals and plants, and are used in a wide range of applications including biological and medical research, the production of pharmaceuticals, and agriculture.

Why GMOs?

One of the most widely adopted uses of GMOs is in agriculturally important crops. In these plants, alterations to the genetic material are often accomplished by inserting DNA material from a different organism into the target organism. This results in the plant (and any seeds harvested from the plant) expressing novel traits, such as herbicide or insect resistance, or quality traits such as drought tolerance. For example, genetic modifications have been made so that plants are resistant to herbicides such as glyphosate or glufosinate, allowing a field to be sprayed with the herbicide to kill off weeds without harming the crop.
Genetic modification can also involve the transfer of a trait or traits that allow the plant to produce endotoxins originating from the soil bacterium Bacillus thuringiensis, known as “Bt”. This confers insect resistance. These endotoxin proteins have been used as spray-on insecticides since the 1920s. They target certain insect species while having no effect on non-target species such as humans, wildlife, and beneficial insects. When ingested, these proteins form pores in the midgut epithelium of the larvae of susceptible insect species (which feed on the crops, causing damage). This causes paralysis of the gut, and the affected insect stops feeding and succumbs to starvation. Non-target species have no receptors in the gut for the protein, and thus the protein has no effect on them. In addition, GMO plants may express quality traits that allow them to be tolerant to environmental conditions such as drought, or to improve their nutritional content.

GMO naming conventions

GMOs may be referred to in one of three ways. First, they may be identified by their event name, which is the name of the unique DNA recombination experiment that occurred in the laboratory in which one plant cell successfully incorporated a desired gene. That cell is subsequently used to regenerate whole plants and is the “foundation” of a GMO strain. For example, one event name for herbicide-tolerant corn is NK603. Second, GMOs may also be identified by the unique protein they express. In the case of event NK603, the protein expressed is CP4 EPSPS. Thirdly, the GMO may be identified by the trade name under which it is sold commercially.

GM crops around the world – then and now

Current GMO production mainly comprises four crops: soybeans, maize, cotton, and rapeseed/canola. Global trade of these crops and their main derivatives is dominated by material of GMO origin. In addition, global planting of these four crops includes a very high percentage of biotech seed (78% of soybean, 64% of cottonseed, 33% of maize, and 24% of canola globally; ISAAA 2016). Within these crops, there are several GMO proteins currently important to the grain and seed trade. The cultivation of GM plants is increasing globally, as is the utilization of stacked traits - including two or more novel traits in the same plant.
The first field trials of GM plants began in the United States and France in 1986, with herbicide-resistant tobacco. The first country to allow commercialized GMO plants was China, which introduced a virus-resistant tobacco in 1992. The first GM crop approved for sale in the US was the FlavrSavr tomato in 1994. In that year, the European Union also approved its first GM plant for sale, which was a herbicide-tolerant tobacco. Commercialized cultivation of GM plants such as corn and cotton began in 1996. In 2016, 11 different types of GM crops were commercially grown on 457 million acres (185 million hectares) in 26 different countries around the world.