Researchers discovered how to add a single E. coli gene to corn that enables it to be grown with an essential amino acid otherwise available only in meat. This could improve nutrition in developing nations and save billions in agricultural costs.
Beefing Up Corn
Methionine is one of nine amino acids that are essential to human health. In addition to supporting tissue repair and growth, it strengthens nails and improves the skin’s flexibility and tone. Methionine also contains sulfur which aids cells in absorbing zinc and selenium, and guards against both pollution and premature aging. Amino acids occur in our food, so nutritionally inadequate diets often lack sufficient amounts of one of more of these critical compounds.
Animals, including livestock, also need methionine. This means that billions of dollars’ worth of methionine must be added to field corn seed annually, since corn lacks the amino acid in nature. For example, according to the study, chicken feed is typically made up of corn and soybeans, so it is typically lacking methionine, the essential sulfur-containing amino acid.
Adding Methionine to Corn
Within this study, researchers inserted a gene from the E. coli bacterium into the genome of the corn plant and then produced several generations of the modified corn. The E. coli enzyme — 3?-phosphoadenosine-5?-phosphosulfate reductase (EcPAPR) — spurred methionine production in the leaves of the plant rather than throughout the plant. This was an intentional choice, with the aim of avoiding an accumulation of toxic byproducts. It was enough to prompt a 57 percent increase in methionine in the corn kernels, and observations of chickens who ate the corn as part of a feeding trial showed that the modified plant was nutritious.
“To our surprise, one important outcome was that corn plant growth was not affected,” Rutgers University-New Brunswick Department of Plant Biology professor and study co-author Thomas Leustek said in the press release. This will be a tremendous boon to subsistence farmers in the developing world, Leustek pointed out: “Our study shows that they wouldn’t have to purchase methionine supplements or expensive foods that have higher methionine.”