Know When To Fold 'Em, Know When To Grow 'Em

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April 28, 1999: Huntsville, AL Any gambler will tell you that odds of 1 in a 1,000, or worse, are not a good bet. Yet, those are the odds facing researchers trying to transfer desirable genes into food and other important crops. A commercial agribusiness experiment on STS-95, however, indicates that microgravity may dramatically change the odds in favor of the researchers and make the operation far less a gamble.

The experiment, flown in a Wisconsin Center for Space Automation and Robotics' (WCSAR) ASTROCULTURE(TM) locker, was designed to test if microgravity would aid the genetic transfer process. Instead of older methods -- such as cross pollination and grafting -- that can take years to produce results, researchers now use bacteria to transfer the gene carrying the desired trait to seedlings. These seedlings will, in turn, pass the trait along to future generations of the plant. In Earth-based laboratories, however, the expected success rate for this process is at best 1 plant in 1,000, or 0.1 percent. To obtain data on the effects of microgravity on this process, industry partners Rapigen, LLC, The Indiana Crop Improvement Association, Inc., Christophersen & Associates, Inc., and the University of Toledo worked through the WCSAR Commercial Space Center to fly the experiment.

In the experiment, approximately 1,000 soybean seedlings had their growing point (meristem) region damaged just before launch, and were wrapped in water-soaked paper rolls that were then placed in a modified ASTROCULTURE(TM) locker. Damaging the growing point provided a point of entry for bacteria containing the gene to be transferred, in this case a marker gene that is fluorescent and easily tracked. The bacteria was mixed into growth media and transferee into the containers with the paper rolls once on orbit.

"The level of genetic transfer was way beyond our expectations," says Ray Bula, a Principal with Rapigen LLC and a retired director of WCSAR. "We thought that if we could double the rate of transfer seen on Earth, it would have been promising."

Instead of simply doubling, according to Bula, there was more than a ten-fold increase in genetic transfer compared with the ground-based control experiment. While this was extremely successful, an unanticipated result was a high rate of infection. For a number of reasons, the growth of bacteria is much more difficult to control in microgravity than it is on Earth. As a result, the high rate of infection blocked the vascular system of the plants. Bula states that this problem can be corrected, in part, by reducing the amount of bacteria since less is needed to do the job in microgravity.

"WCSAR is excited about the outcome of the gene transfer experiment conducted during the STS-95 mission," states Dr. Weijia Zhou, Director of WCSAR. "This is an another illustration of the successful collaboration between WCSAR and its industrial partners. Thanks to NASA, WCSAR and its industrial partners were able to perform this novel experiment in the microgravity environment. These results are the first steps leading to genetic engineered commercial products that will contribute to the economic competitiveness of U.S. industry."

While cautioning that further experimentation is needed to verify the results and refine the methodology, Bula is excited by the results. And for good reason: genetically engineered varieties will make up more than 70 percent of the soybeans planted nationally this year, and improved gene transfer opens the door to a host of other exciting possibilities including plants that are insect resistant -- reducing the need for chemical insecticides -- and plants that incorporate medical vaccines.

Work is already underway on a second gene transfer experiment. This experiment will include refinements from the data gathered on STS-95, and instead of a marker gene will transfer a gene to the soybeans that has a medical application.

Commercial experimentation, such as the successful experiments in ASTROCULTURE(TM), are made possible through NASA's Space Product Development Program, a partnership between NASA, academia, and U.S. Industry. Working through Commercial Space Centers that are funded by both NASA and Industry, companies can do research designed to produce the products and technologies of tomorrow. The research effort belongs to the industries involved, who are responsible for designing, funding, and analyzing the research. NASA, as its part of the partnership, provides access to microgravity for selected research.