Genetic engineering refers to a process by which the genetic material of an organism - the DNA - is altered in a way that does not occur naturally through mating or natural recombination (Europa, 2003). Bacteria are commonly used for genetic engineering in plants (Lessick, Keithley, Swanson and Lemon, 2002). Bacterial plasmids, which are short loops of DNA, are cut with a restriction enzyme and mixed with a gene to be inserted into a plant. DNA ligase, an enzyme, is then used to attach the gene into the plasmid. The plasmid are now known as recombinants because they contain a combination of their original DNA and the DNA of the gene which has been added to them. The recombinant plasmids are then mixed with bacteria which can incorporate them, and the bacteria are cultured to grow in large amounts. This results in multiple copies of the recombinant plasmids with their newly incorporated gene being produced. The plasmids are extracted from the bacteria and the cloned genes extracted with a restriction enzyme. The gene can then be introduced into individual plant cells using a bacterial vector (carrier).
This technology is used in agriculture to produce crops resistant to disease, to increase crop yields, and to make crops tolerant to normally unsuitable environmental conditions (Lessick, Keithley, Swanson and Lemon, 2002). It can also be used to improve flavor and texture, increase shelf life, and add nutritional value. An example of genetic engineering in plants is the introduction of a gene for tolerance to glyphosphate herbicides such as in Roundup Ready corn (Anderson, 2003). The gene can also be introduced into soybeans, cotton, and canola crops. The plants can also be bred to be resistant against corn borer and rootworm, which considerably increases crop yields. This kind of technology is particularly significant for developing countries where starvation is rampant.
In humans, genetic engineering is only in ...