Crops That Can Shut Off Pests' Genes

With the rising public concern about the consequences of pesticide use, scientists are looking toward a more molecular way of protecting crops. Traditional pesticides bring in concern about insect resistance, environmental damage, and human exposure risks. However, there is a characteristic of plants that can be tweaked to make an environmentally safe pesticide. Plants are among the Eukaryotas that have the ability to "turn off" genes via RNA interference of translation. While these genes are turned off by the interference, certain proteins can not be produced. Plants and animals use this RNA interference all the time to stop over expression of certain genes and proteins. Scientists are looking to weaponize this RNA interference against pests and protect important crops. Rather than traditional pesticides that are sprayed on plants and overwhelm pests' nervous systems, these plants are being genetically engineered to produce siRNA that shut down important genes in bugs and worms. For example, some plants have been modified to produce toxins from bacterium that can poison beetles and moths or that shut off something as important as cellular sorting. "RNA interference-based pest control can provide protection at essentially no cost because once the variety is developed, the plant can just go on using it instead of needing additional applications of insecticide," says co-senior author Ralph Bock, a director at the Max Planck Institute of Molecular Plant Physiology in Germany. There is an obvious concern as to what happens when humans consume these genetically modified plants. Will we too suffer the same fate as the pests? "The objections to transgenic proteins involve concerns about their possible toxicity or allergenicity to humans, but with the RNA interference strategy there's no protein that is made, just some extra RNA," Bock says.