New mode of action could play role in next stage of GMO crop development

Sometime between now and the end of the decade Monsanto plans to launch a new corn rootworm 3 trait that could give corn farmers a much-need additional option for controlling rootworms. The trait will use a relatively new tool called RNAi, a concept first discovered 10 years ago that allows plant to turn off processes as well as start new ones as with more traditional genetic modifications. Monsanto’s Robb Fraley discussed the new concept in an interview at the Farm Progress Show.

RNA is the abbreviation for ribonucleic acid, a family of molecules that perform vital roles the expression of genes. The little i stands for "interference." RNAi is being used extensively in pharmaceuticals and is beginning to become part of the gene strategies of companies like Monsanto. Essentially the protein in this corn trait will shut off a key RNA sequence in the rootworm, and it dies.

For Fraley, who is being honored with a World Food Prize next month, new ideas for genetics aren't a surprise, he pioneered techniques to insert new genes into plants and led the team that developed glyphosate-tolerant crops. Yet this RNAi technology has Fraley rethinking his molecular biology background. "This is a phenomenal discovery," he says. He notes that in his early days in molecular biology the thought process was that DNA made RNA which produced a protein. Today, the RNAi concept is gaining ground in new ways - so the DNA makes a specific RNA-interference molecule that triggers a specific effect in a pest, disease or elsewhere.

For Monsanto, they had to characterize the rootworm to find a common gene for the rootworm alone that would be stopped by this interference. It's highly technical, but superbly precise in its application [3]. But that's the nature of biotechnology from the start. It's a much more precise science than in the past and one that has changed the way we farm. RNAi has longer term potential in other ways too, Fraley said in a recent article in Farm Industry News [4].

The RNAi approach, while in a plant for the corn rootworm 3 gene Monsanto is testing, could be used in spray applications or in other ways in the future, Fraley explains. It could be used to turn on or turn off key traits or actions in a plant to specifically modify production.