New GE corn could mean consumer health benefits
A new Frankenfood is on the scene: corn with bacterial genetics that tell it to produce the one essential sulfur amino acid it doesn’t already make.
Rutgers University biologists, with funding in part from the Department of Energy, took a gene from a common intestinal bacterium, Escherichia coli, and inserted it into the corn genome to produce a plant that is high in the nutrient methionine. When added to the corn genome, this gene produces kernels with 57% more methionine while yielding the same harvests as conventional, non-GMO corn.
Methionine is an essential amino acid, meaning it is one of nine proteins our bodies can’t produce themselves but need in order to function. A more nutritious corn cob saves farmers money on animal feed, which according to the latest USDA Census of Agriculture, is their biggest expense.
Primarily feeding their animals corn means farmers must purchase nutrient supplements to simulate a varied diet. The more nutritional needs corn fulfills, the more money farmers save on inputs, such as synthetic methionine, while still raising healthy animals.
This study ran field trials in which researchers fed five-day-old chicks their GE corn for four weeks. They compared the growth of those chicks to a group that was fed regular corn with synthetic methionine, and another group fed regular corn without a methionine supplement. Chicks fed GE corn and corn with methionine added grew at the same rate, whereas those fed regular corn were smaller. This proved that the researchers made corn which carries within its kernels bioavailable methionine.
They achieved this success after decades of testing different adjustments to the corn genome. The winning alteration proved to be inserting a gene that disrupted the use of sulfur in corn leaves. Researchers observed that making this modification in the part of the genome responsible for leaf expression resulted in a kernel richer in methionine, but any side-products of the reaction that produces methionine remained in the leaves. Typically, the plant uses sulfur to produce the amino acid cysteine, but the inserted gene halts that process so that sulfur becomes an input to produce methionine instead. Cysteine cannot be used to produce methionine, but methionine can produce cysteine, so an increase in methionine means the body still has the resources to maintain desired cysteine levels too.
Working on this project since 1978, Joachim Messing, a Rutgers University microbiologist, recognizes that consumers are skeptical of genetically engineered produce.
“The consumer doesn’t have any benefits whether [their food] is transgenic or not… …Consumers won’t have a change of heart as long as transgenic plants are only something that benefits the farmer.” said Messing.
Biotechnologist Alison Van Eenennaamen of University of California — Davis said, “The [GMO] debate is no longer about science…it is about politics and often fearmongering to suggest that GE is somehow unsafe when used as a plant breeding tool, but not when used as an additive like GE chymosin for cheese making, or GE synthetic amino acids [to add to animal feed].”
Messing says they’re investigating lysine-rich corn next. Without this other essential amino acid, a body cannot absorb calcium properly or build muscles. If corn was rich in both methionine and lysine, then farmers wouldn’t buy soybeans, naturally full of lysine, or rely on synthetic lysine. All they’d need is corn.
Link to original research: http://www.pnas.org/content/114/43/11386.abstract