Transgenic Bt Crops (Genetically Modified):

There are different ways of moving genes in a plant to produce desirable traits. One of the more traditional ways is through selective breeding. A plant with a desired trait is chosen and bred to produce more plants with the desirable trait. More recently with the advancement of technology is another technique. This technique is applied in the laboratory where genes that express the desired trait is physically moved or added to enhance the trait in the plant. Plants produced with this technology are considered to be transgenic. Many times it is also referred to as Genetically modified (GM).

Results of insect infestation on Bt (right) and non-Bt (left) cotton bolls. Source: USDA

Other GM products

Genetically engineered products are not new. Insulin used today in medicine is an example of genetic engineering; the insulin gene from the intestines of pigs is inserted into bacteria. The bacterium grows and produces insulin; this insulin is then purified and used for medical purposes. Thyroid hormones, until recently was derived only from animals, now the hormone can be cultured from bacteria. Other genetically engineered products include the chemical Aspartame used in sugar free foods, and the drug hepatitis B vaccine.

Engineering vs breeding

So why use molecular biology over traditional breeding? With traditional breeding, plants often exchange large, unregulated chunks of their genomes. This can lead to both useful and unwanted traits in the offspring. Sometimes these unwanted traits can be unsafe. One example would be potato varieties made using conventional plant breeding that inadvertently produced excessive levels of naturally occuring glycoalkoloids. These glycoalkoloids cause cause gastrointestinal, circulatory, neurological and dermatological problems associated with alkaloid poisoning.

Breeders sometimes have to cross many plants over multiple generations to produce the desired trait. GM techniques allow new traits to be introduced one at a time without complications from extra genes and extensive crossbreeding. GM techniques also allow traits from different organisms to be applied, such as pest resistance.

Types of GM plants

Most GM crops grown today have been developed to resist certain insect pests. There are GM plants being developed today to produce specific vitamins, resist plant viruses and even produce medical …insulin. Countries that grow GM crops include; Argentina, Australia, Canada, China, Germany, India, Indonesia, Mexico, Portugal, South Africa, Spain, United States, Ukraine, and many more.