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Soybeans, Roundup Ready®

Plant of the Week

Roundup Ready® Soybeans
Latin: Glycine max

Picture of soybean plants with soybean pods.
Soybeans were the first widely planted crop developed using genetic engineering techniques.

To conclude our somewhat extended examination of how new plants are developed, we must consider the soybean.

Plant breeding techniques have changed dramatically since 1990 as genetic engineering moved from the realm of academic theory to crops growing in the fields. Now, more than a decade into the use of this new technology, soybean (Glycine max ) is probably the best example to illustrate the power of direct gene manipulation.

Genetic engineering involves the insertion of a portion of one organism's DNA into the genetic code of another. Because DNA is fundamentally alike across the plant and animal kingdom, the gene fragment that is inserted can come from either a plant, an animal or a bacterium. These genetically modified plants are usually referred to as GMOs (genetically modified organisms), except in Europe where the more provocative "Frankenfood" is preferred.

The basic premise used in plant improvement we have been discussing for the last couple months have all involved rearrangements of genetic information at the DNA level. But, in conventional breeding systems, a degree of likeness has been required so that the plants could come together in a sexual union.

But, in genetic engineering, this relationship requirement is short-circuited. If a gene can be identified with a particular desirable trait, it can be isolated, multiplied and inserted, at least in theory, into any other organism.

The technique of genetic engineering grew out of Richard Nixon's war on cancer initiative he launched in 1971. Federal money was directed to understand how genes worked and how tumors grew.

A plant pathologist working on her Ph.D., Mary-Dell Chilton, made a fundamental discovery - namely how the crown gall bacterium was able to cause galls to form by inserting a portion of its own genetic code into the host plant. Her work coincided with an explosion of knowledge in tissue culture propagation techniques, making it possible to grow any plant from a clump of cells, a requirement as DNA modification takes place at the cellular level.

Chilton's work with the ti-plasmid identified the first practical method of inserting genes into DNA strands. By the early 80s, industries began to see the potential for the technology and began to hire away university researchers to staff their new genetic engineering labs.

A biotech boom developed on Wall Street with dozens of new firms all competing for scientists and investment dollars. Most of these firms made claims they could not deliver, and eventually consolidated. Monsanto Corporation of St. Louis , known primarily as a plastics manufacturer prior to the biotech boom, ended up as the principle agricultural player using this new technology.

In the 1970s, Monsanto developed a non-selective herbicide they called Roundup® that became and remains an important material for all sorts of weed control programs. But to use it in crop production, the spray had to be targeted to hit just the weeds, not the growing crop. Monsanto scientists saw genetic engineering as a way of building a better mousetrap by developing field crops that were resistant to their herbicide.

From 1980 onward, most of the advances in genetic engineering were made by corporations with lots of resources and people to throw at the problem. The first thing they did was to patent all of the various and sundry steps involved in the genetic engineering process, even though they were not fundamentally different than the techniques developed by the academic scientists before being hired by away by industry.

During the heyday of development during the early 1990s, Monsanto had as many as 300 people working in biotechnology research. Finally, from the muck beneath a waste storage facility in Louisiana where the herbicide was manufactured, they discovered a bacterium that was able to metabolize the herbicide.

The gene responsible was identified and then inserted into soybeans about 1993. With the gene in place, breeders could then use conventional breeding techniques to create new hybrids or open pollinated lines that show Roundup resistance. Now, Roundup could be sprayed directly over the crop without injury, thus increasing the sale of Roundup, but still reducing the overall cost to farmers.

The first trial plantings went out in 1996. By 2000, about 80 percent of the soybean production in Arkansas was converted to Roundup Ready® beans. Such quick, widespread adoption by farmers is an indication of the power of the technology and the fact it makes economic sense, even though farmers are required to buy new seeds each year, and they must pay a $6.50 "technology fee" for the privilege of growing the new cultivars.

This gene, and many others, has been inserted into all major field crops. It has recently been inserted into bermudagrass and bentgrass, but their release is being delayed as EPA approval is sought. Other than blue carnations containing petunia genes, few ornamentals have yet been developed using the new technique. As the patents on the needed techniques expire in the coming years, this situation will change and there will be a bewildering array of plants with all kinds of undreamed of characteristics.

By: Gerald Klingaman, retired
Extension Horticulturist - Ornamentals
Extension News - September 24, 2004


The University of Arkansas Division of Agriculture does not maintain lists of retail outlets where these plants can be purchased. Please check your local nursery or other retail outlets to ask about the availability of these plants for your growing area.