How Is DNA Technology Used to Produce Genetically Modified Food?

Genetically modified foods contain altered DNA.

Genetically modified foods, mostly crop plants, are becoming more prevalent throughout the world. Through application of DNA technology, scientists can confer plants with resistance to herbicides, higher nutritional value or better storage characteristics.

DNA and Genomes

All living things, including food plants and animals, contain genetic material that controls how they function and reproduce. This genetic material is deoxyribonucleic acid (DNA), and the total DNA content of an organism is called its genome.

Genetically Modified Foods

Genetically modified foods contain intentionally altered genomes. Genomes are altered by changing DNA sequences to introduce desirable traits.

Pest Resistance

One way to modify a plant genome is by inserting genes. For example, introducing a gene from the bacterium Bacillus thuringiensis, which codes for a protein that is toxic to insects, gives plants resistance to insect predation.

Herbicide Resistance

Plants are made resistant to glyphosate or glufosinate herbicides by introducing DNA from bacteria into their genomes. This allows growers more flexibility in applying herbicides to crops.

Antisense Technology

Some plants are genetically modified with genes having their coding sequences reversed (antisense) from those of normal genes. This deactivates the genes, preventing them from functioning. One use of this is to slow softening in tomatoes as they ripen.

Nutrition

Genes from other plants or bacteria are inserted into plant genomes to enhance production of important nutrients such as vitamins A and C and folic acid.

References

• Biotech Knowledge Center: Biotech Basics

Resources

• Human Genome Project: Genetically Modified Foods and Organisms