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9.7.2009 Hungry? How About Some Protein-Rich Cotton...


It's as true in today's world as it was in the antebellum South: cotton is king. The plant has been cultivated for its fiber for over 7,000 years, and today it's grown by more than 20 million farmers in some 80 countries. But while cotton accounts for nearly 40% of the fiber used worldwide to make clothing, there's one thing the plant has never been able to do well: feed people.

Cottonseeds are a rich source of protein--the current cotton crop produces enough seeds to meet the daily requirements of half a billion people a year. But the seeds can be consumed only after an extensive refining process removes the gossypol, a toxic chemical that helps protect the plant from insect and microbe infestation.

"People, pigs, chickens--none of us can stomach gossypol," says Kater Hake, vice president of agricultural research for the industry group Cotton Inc. Only cows and other ruminants can handle it.

Remove the gossypol, however, and you'd have a cheap and abundant form of protein for everyone. But get rid of all the gossypol, as plant breeders did in the 1950s, and insects will devour the defenseless cotton. Enter Keerti Rathore, a professor at Texas A&M University, who found a way around the problem through genetic engineering.

In new field-trial data, Rathore's team demonstrated that it can turn off the genes that stimulate the production of gossypol in the cottonseeds while the rest of the plant keeps its natural defenses.

"This research potentially opens the door to utilizing safely the more than 40 million tons of cottonseed produced annually as a large, valuable protein source," says Norman Borlaug, an American agronomist who won the Nobel Peace Prize in 1970 for developing high-yield wheat varieties that have helped increase the world's food supply.

Rathore used a new technique, called RNA interference, to construct a genetic sequence that blocked the gossypol-producing enzyme in the seeds only. After succeeding in the lab, he began a test in a greenhouse to see if the genetically modified cotton plant would survive and pass on its new trait.

Rathore's just-compiled data show that the modified cotton appears to be normal in every way other than the fact that it has instantly edible seeds. "What works in the greenhouse should hold true in the fields," he says.

Genetically modified cottonseeds will need government approval before they hit grocery shelves, and they're more likely to be used first to supplement fish or animal feed. But with the global population still on the rise and farmland limited, the planet can use free protein. And you might even like it. "It's not bad," says Rathore, who has popped a few seeds. "Tastes like chickpeas."