HELSINKI — Conventional pesticides are a double-edged sword that scientists are now seeking to replace with more natural RNA-based plant vaccines.<br /><br />The U.S. Department of Agriculture estimates that without pesticides, roughly 70 percent of the world's crops would be lost to pests. But such chemicals are toxic — killing insects but also affecting the rest of the environment.<br /><br />New research in the Plant Biology Journal details an approach that involves directly spraying plant leaves with an RNA-based vaccine. Developed in France and Finland, this inoculates against specific pests or pathogens.<br /><br />The vaccine triggers a process called RNA interference, which prevents invading RNA strands from carrying out their functions, thus causing the pest to die.<br /><br />RNA molecules in the vaccine do not negatively affect the host plant. The RNA also has the added benefit of being biodegradable because it breaks down quickly.<br /><br />Instead of chemical synthesis, scientists used a bacteria-eating virus called a bacteriophage to help generate the RNA.
