Genetically modified foods are products that have been manipulated by introducing organisms whose DNA structure has been changed slightly using genetic engineering methods. This allows several alterations in the way the plant grows and also the quality of the yield.(Liang, 20). There have been controversies and debates over the years on whether or not these foods are harmful to man. These plants are engineered genetically in the laboratory by changing their genetic structure and make up and then tested to check if they have acquired the desired results and quality.
The engineering involves either adding a gene or genes to the plant’s genome or removal of the genes. (Freedman, 2009). .The methods used include gene guns, microinjection, electroparaton and agrobacterium. There are advanced methods that are more convenient which are the Crispr and Talen techniques. (Halford, 2006). .
The gene guns technique uses radiations that are target the genes into a cell of a plant. The new DNA is combined to very small particles of tungsten or gold which are then shot into the target plant tissue or cell and all this is subjected to high pressures. The particles enter the cell membranes/cell wall and the DNA enters into the nucleus by detaching itself from the metal. This method has been used mainly in the production of maize and corn. The agrobacterium method uses the agrobacteria-organisms that are parasitic in nature and have the ability to transfer genes. They insert their genetic materials in a plant to create a convenient environment for themselves. This organisms are used in genetically engineering by removing their DNA and replacing it with the intended gene, allowing the transfer of the gene into plants.
This method has been commonly used to produce tomatoes and potatoes. The electroparation is mainly used in plants whose cells do not contain a cell wall. Here, electric pulses cause the DNA to be put into the target plant cell through pores. Microinjection involves directly injecting a gene into the target plant’s DNA.
The most common food alterations is concentrated mainly in cash crops that have high demand for example, soybean, corn and canola seeds. They are altered to make them resistant to diseases and to tolerate herbicides improving their quality.
There are three types of modifications:- the transgenic method that involves the transfer of genes from one plant to another or from a bacterium to a plant. These plants are used to make or process proteins that help in making the plant tolerant and resistant to herbicides and diseases. (Parekh, 2004) The corn is genetically altered to help it tolerate some herbicides and produce a protein that kills most insects that may attack it. Soy has also been similarly altered to help it tolerate herbicides.
The other method is the cisgenic method in which the plants are created by genes from species that are closely related or are same in nature. An example is the potato. The fruits and vegetables for example papaya are genetically modified by crossing genes to make it resistant to a virus that was notorious called the ringspot virus. (Ruse & Castle, 2002). .The last method is the subgenic method that involves the deletion of the genes. The sugar beets that make sugar are grown with a resistant seed and they are genetically modified by removal of both DNA and protein.
Freedman, J. (2009). .Genetically modified food: How biotechnology is changing what we eat. New York, NY: Rosen Pub. Group
Halford, N. G. (2006). .Plant biotechnology: Current and future applications of genetically modified crops. Chichester, England: J. Wiley.
Liang, George H, and Daniel Z. Skinner (2004). .Genetically Modified Crops: Their Development, Uses, and Risks. New York: Food Products Press
Parekh, S. R. (2004). .The GMO handbook: Genetically modified animals, microbes, and plants in biotechnology. Totowa, N.J: Humana Press.
Ruse, M., & Castle, D. (2002). .Genetically modified foods: Debating biotechnology. Amherst (N.Y.: Prometheus books.