Monsanto Vs. Western Corn Rootworm: A Pesticide-free Solution to Corn’s Squirmy Nemesis?

Monsanto is nearing completion on four breakthrough products that are set to turn the pesticide world upside down and in the process help alleviate the stress put on bee populations from overuse of other chemical pesticides.

cornThe most important of these new products is working its way through the regulatory process. It targets the Western Corn Rootworm which can devastate corn crops and causes nearly a billion dollars in losses annually. Ultimately the research being done by Monsanto, and others, goes far beyond targeting just one pest, it represents a fundamental shift in how farmers will deal with pests.

These new products make use of RNA interference(RNAi) to target genes specific and vital to the pests, while remaining benign to non-target species. The same RNAi process was used to insert genes into grapes by OSU researchers to strengthen local wine crops.

RNAi is, according to the National Institute of General Medical Sciences, “a natural process that cells use to turn down, or silence, the activity of specific genes.”

First discovered in the 1998, RNAi based therapeutics represent a fundamental departure from the way agribusiness traditionally deals with pest problems.

Instead of spraying tons of chemicals over vast tracts of land, that then seep into lakes, rivers, and underground water wells, plants will be able to make use of evolutionarily evolved pathways to fight off modern day pests. The method is both environmentally more friendly and cost effective.

After over a decade of research, and with a plethora of data demonstrating that existing pesticide use patterns are causing widespread declines in non-target species, like Oregon Honey Bees, RNAi based therapeutics offer a way to selectively target pests, while allowing the host plant to remain non-toxic to humans and other non-target species.

In an interview with American Association for the Advancement of Science, journalist Kai Kupferschmidt, noted that, “the clever thing is that only insects who actually eat off the plant will come into contact with the RNA, and you can also make the plant express this RNA only in the roots, for instance, if you’re talking about larvae that feed on the roots.”

There are, however, some potential concerns. Molecular biologist Chen-Yu Zhang, from the University of Nanjing found evidence of MiRNA, from rice consumed by humans and mice, surviving the digestive tracts, something thought to be impossible, and inhibiting genes responsible for protein production in the liver.

Phillip Zamore, Professor of Biomedical Sciences at the University of Massachusetts Medical School, argued that the potential risks from RNAi based GMOs were low because of the relatively low concentrations of exogenous MiRNA found. Endogenous MiRNA exists in concentrations of near 500,000 parts per cell, while in Zhang’s research, he found less than 1000 parts per cell of rice MiRNA.

With chemical pesticide use on the rise globally, threatening ever more non-target species and environmentalists up in arms about the potential toxicity of existing protein based GMO’s, this new method offers an opportunity to protect non-target species, reduce chemical pesticide use, all while not increasing risks to the human populations.

By William Tatum