What is GMO corn and is all corn genetically modified?

Expert response from Rod Herman

Senior Advisor, Biotechnology Regulatory Sciences Group, Regulatory Science and Government Affairs Department, Dow AgroSciences

Friday, 13/12/2013 13:21

‘Is corn a GMO?’ is a very common question when discussing GMOs. In my response, I’ll cover some GMO corn facts and whether or not all corn is GMO.

Firstly, how is corn genetically modified? Well, corn has been grown by humans for approximately 10,000 years and its genetics have been heavily modified through breeding and mutation to improve its utility as a crop over this very long period. The modern technique of transgenesis has been used to further improve the agronomic characteristics of corn over the last two decades. Transgenesis has become synonymous with the term “genetically modified” (GM) over this time period, but it is really a misnomer.

There is also Bt corn which has had the Bacillus thuringiensis gene engineered into it. This means that Bt corn produces an ICP toxic to the pest species of concern. As the insect feeds on the corn, it ingests the ICP and suffers the same fate as if it ingested leaf tissue sprayed with Bt. After Bt corn, the only other Bt crop registered in the US is Bt cotton.

So, is all corn GMO? Yes, technically all corn on the planet has been modified by human activities – or, put simply, there’s no such thing as non-GMO corn – but only around 80% of corn in the US has transgenes inserted by the modern technique of transgenesis.These GM corn varieties have been created with insect resistance traits to help farmers more easily manage pests – such as the corn borer or corn rootworm – and protect their harvest.

Corn is planted on about 80 million acres in the United States with most of the crop grown in the Midwest. About 99% of the corn grown is field corn, with the remaining 1% being sweet corn. Interestingly, though, most of the corn grown in the US isn’t produced for human food consumption. Instead, corn is produced to create food for livestock, fuel for our cars, oil for sunscreen and water bottles, starch for magazine printing and sidewalk chalk. Corn is also used to make matchsticks, crayons and carpet, and more.