August 16, 2005

Scientist develops corn that can weather drought

by K.C. Jaehnig

CARBONDALE, Ill. -- Corn with a gene from a common soil microogranism can weather a drought while yielding roughly 10 percent more than corn that lacks the gene, researchers from Southern Illinois University Carbondale have found.

"Drought is the farmer's most damaging problem, but it hasn't gotten the investment it deserves because before transgenes, traditional breeding wasn't working as hoped — most drought-resistant cultivars just yielded less," said biotechnologist David A. Lightfoot, who developed the transgenic corn and headed the 10-member research team that tested its properties.

"True drought resistance, where the corn goes on growing when there's no water, doesn't exist, but this corn suffers only slightly and recovers quickly,"

The yield advantage doesn't occur in wet years. With sufficient water, the transgenic corn and its unaltered counterparts perform pretty much the same. Still, because most farmers never know ahead of time when they're going to have a dry year, buying seed corn that can take drought stress might serve as a kind of insurance. Certain farmers could find it a crop saver.

"For those in locations that are consistently dry, this would be a very sensible technology to apply," Lightfoot said.

The genetically modified corn has more going for it than just its ability to survive a drought. It can capture 10 percent more of the nitrogen in ammonium-based fertilizers than unmodified corn and also can tolerate Liberty, a popular weed killer.

"It's not as strong a resistance as in the commercial one, but it uses a different mode of action," Lightfoot said.

"This is important because we're starting to see weeds resistant to our regular, trusted herbicides. Being able to make super-resistant crops (by combining modes of action) will matter increasingly in the future as these resistant weeds start to spread."

And that's not all. Because of a small change in its amino acids, the modified corn may be slightly more nutritious.

"Our animal scientists are looking at this and finding modest effects in digestibility and growth rate," Lightfoot said.

"We would like to stack our gene with one or two others, cross that with a quality protein maize and then test the grain in animals next season. Even a modest effect could be hugely valuable to the animal husbandry industry. A 1 percent increase in corn protein could be worth an extra $360 million a year in profits."

Lightfoot began engineering this line of genetically modified corn shortly after his arrival at SIUC in 1991. Along the way, he's received financial support from the Herman Frasch Foundation, the Illinois Council for Food and Agricultural Research, the Illinois Maize Marketing Board and the Illinois-Missouri Biotechnology Alliance.

"Support such as these agencies provided is essential to testing new ideas, and returns on the investments are massive — 17 to one on average in ag biotech." Lightfoot said.

"Soybeans, for example have become a $15 billion-a-year industry because of an investment of about $5 million made in the 1920s and ‘30s."

Corn containing the SIUC gene could go on the market in the next three to five years.

"We're in a bidding war between two companies happily enough, although the GMO (genetically modified organism) wrinkle could make it (commercialization) much slower," said Lightfoot, who, in the late 1990s saw the global market for transgenic crops crumble because of opposition from countries belonging to the European Union.

However, things have changed since then. Last month, for example, the European Food Safety Authority concluded that three American corn hybrids bred from genetically modified parents posed no health or environmental threats.

"Clearly, the moratorium in Europe has relaxed, so products like drought-resistant crops could get an easy pass for places like sub-Saharan Africa," Lightfoot said.

"We're very excited about the prospect. This is a technology that could give biotechnology a better name. If we can get this gene into crops in countries that traditionally suffer from drought, we will be doing something for the poor people of the world."

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