Papaya fruita on a tree infected with the papaya ringspot virus. The fruits are showing blemishes typical of infection.
MOST OF us have heard at least a little about foods which have been genetically engineered (GE) or modified (GM). But do we know how these products are developed? Do we know what should be of concern? Do we know the process of development of the product?
Manipulating crops is not a new concept. For thousands of years farmers have mated closely related plants, randomly mixing all of the plants' tens of thousands of genes to develop the crops we presently consume; from cucumbers and carrots to white rice and wheat, the list is endless. However, the odds of producing a crop with all of the desired traits are similar to our winning 'Pick Three' or 'Lucky Five' today.
In the late 1990s, GE technology initiated a revolution in commercial agriculture. Through this technology the development of improved crop plants is more precise and can occur between plants that are not closely related. For example, the trait that allows a soil-dwelling microorganism to make a natural pesticide that is toxic to insects but harmless to humans and other animals can be transferred into a plant, thereby enabling the plant to fight off insects.
Or, traits that allow daffodils to produce vitamin A can be transferred to rice resulting in the production of more nutritious rice grains (also called golden rice).
COLLECTION OF MANY TECHNOLOGIES
GE technology is actually a collection of many technologies involving isolating and multiplying fragments of DNA, adding or deleting parts of DNA, transferring the DNA to bacteria, and then inserting the DNA into a cell of a plant (or an animal).
The application of GM techniques results in a genetically modified or transgenic organism. The process of modifying and transferring DNA is possible because DNA is the blueprint of all life. Think of a plant's DNA as a long, detailed sentence that describes all the characteristics of the plant; for example thick leaves and branched stems.
Plants have many of the same words or genes in their sentences, but some have a few unique words describing different characteristics; for example, tolerance to herbicides. GE technology allows scientists to take the words or genes from one plant (or animal, virus or bacterium) and insert them into
another plant, thereby transferring new characteristics to the plant. One of the main challenges of the technology, however, is to ensure that the new words or genes are translated properly and do not adversely affect any part of the plant's sentence.
