From Seed to Seed:
Plant Science for K-8 Educators

Genetic Engineering

There has been little controversy over the previously mentioned breeding activities. Indeed, plant breeders have been credited with saving the world from starvation with new and improved hybrid crop plants! However, the end of the 20^th century heralded a new age in plant breeding.

As techniques improved over the years, plant breeders were able to cross more distantly related plants. In the last few years, some remarkable work has been done, with the potential to change how the world's food supply is produced and distributed. Genetic engineering is a new and often misunderstood technology that will certainly be in the news for years to come.

Over the last several years, advances in cell and molecular biology have allowed scientists to delve more deeply into the world of plant genetics. You'll remember that a cell's genetic material occurs in DNA strands within the cell's nucleus. Scientists are now able to remove a portion of a chromosome and replace it with a piece of chromosome taken from another organism. This type of cell manipulation has dramatically accelerated the world of plant breeding. Rather than crossing and growing out generation upon generation of bean plants, for example, scientists can, in essence, splice the desirable genes into a plant cell. This single cell is then placed in a special nutrient medium that stimulates it to begin dividing; eventually the cells begin to differentiate and a complete plant is formed. Because the genetic material is contained in the initial cell, the new genes are incorporated into every new cell.

Plants and foods created using this technology are called transgenic, bio-engineered, or genetically engineered. In contrast to performing conventional plant breeding, scientists can now take genes from virtually any living organism and insert them into another, totally unrelated organism-even from animal to plant.

The possible uses for this technology are limitless. For example, if scientists were able to transplant the genes that allow peas to fix nitrogen (use nitrogen from the atmosphere) into corn plants, there could be a dramatic reduction in the need for fertilizing with nitrogen. This would impact water quality by reducing fertilizer runoff and help farmers unable to afford synthetic fertilizers. Other possible applications include altering wheat so that it contains more complete proteins, or introducing genes for frost tolerance in otherwise tender plants.

Critics are quick to point out, however, that this is a field of study unlike any that has preceded it. Genetic engineers tinker with what might be considered the very essence of life-the genetic code-and to some, this power conjures up images of Frankenstein's monster. To many people, the risks outweigh the benefits, and at the very least they believe the process should be strictly regulated.

A great way to approach this subject with your students is to have a debate. Divide the class into two groups. One side can be pro-genetic engineering and the other side anti-genetic engineering. Students then research either the benefits or the risks associated with genetic engineering and present their findings in a debate format. In this way, they will educate themselves and grapple with this important topic that has wide-ranging implications.

Would you like to know more?
Additional Online Resources

• Genetic Science Resource Center at the University of Utah.
  http://gslc.genetics.utah.edu/teachers.html

• BioChemNet-A guide to biology and chemistry resources on the web.
  http://www.schmidel.com/bionet.cfm

• MendelWeb.
  http://www.netspace.org/MendelWeb/MWtoc.html

• The American Chestnut Foundation-Restoring the American chestnut to Eastern forests through a scientific breeding program and cooperative research.
  http://chestnut.acf.org