The Difference Between Transgenic Plant DNA and Plant Breeders’ DNA Tools (PCN Winter 2013) JAN 1 2013 | Consumers and Producers | Pulse Crop News
This article appeared in the Winter 2013 issue of Pulse Crop News.
Transgenics plants are created through the introduction of DNA that originates from another species. This could be from a closely related species of plants or from as distant a species as a bacteria, fungi, or animal species. Transgenics are also referred to as GMOs or Genetically Modified Organisms. They have been used commercially in crop plants now for 20 years in many of the large scale agricultural species, such as corn, soybeans, cotton, and canola. While that is the case, there are still areas of the world that are resistant to the use of these GMO crops and their products, such as much of the EU and Japan.
Every time transgenic DNA is inserted into a strand of plant DNA, it is referred to as an “Event.” Each Event is characterised separately; this is due to the nature of the gene insertion mechanism, which is arbitrary in location. Each time a gene is inserted in a new location, it can affect the other surrounding genes on the DNA strand – turning on or off gene expression that was not intended. Because of this, every Event must be assessed; this assessment is regulated by the Canadian Food Inspection Agency (CFIA). Additionally, the CFIA (and similar organizations in other countries) require the creators of GMO crops to put each Event through extensive testing prior to commercial release. This is a time-consuming and expensive process.
Transgenics technology is widely used at the laboratory level, in many species, to test gene function and expression. These Events may be tested under field conditions only under strict isolation conditions as directed by the CFIA or other government regulators. These test Events can be used to quantify the expression of genes and their effects on plant development in real crop environments.
As DNA-based technology has become more developed and less expensive, plant breeders globally are using DNAbased tools to follow the genes present in their specific crops to accelerate and improve the efficiency of their breeding programs. DNA markers, as used by plant breeders, do not change the DNA of the plant; they simply allow a plant breeder to identify and follow genes and traits in plants. Marker assisted selection allows plant breeders to use genetic differences found in DNA strands rather than the trait (for example, Cotyledon color and disease resistance) itself in selecting plants. Marker assisted selection can be useful for selecting traits that are difficult to measure, vary across different environments, or are masked by other genes, such as in disease resistance genes.
These advances, both the use of transgenics and marker assisted selection, have come from our growing understanding of plant DNA and DNA tools. New traits that did not exist in a species can be introduced through transgenics. Specific genes in a species can be targeted, efficiently and accurately selected, and bred into new plant varieties with marker assisted selection.
These techniques are two different DNA-based approaches to providing both producers and consumers with high yielding, equally nutritious, and more reliable food production.