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Plant 'senses' predator and defends itself, study finds

Wednesday, July 09, 2014 - 01:41

Scientists at the University of Missouri discover that the mustard plant can discern the sound waves predators make when feeding and defend themselves by creating a chemical repellant. They hope the research will lead to better methods of protecting crops from insects without the need for chemical pesticides. Sharon Reich reports.

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STORY: To some it's the sound of dinner. But for this plant, it's the sound of danger. A team of scientists at the University of Missouri led by Heidi Appel, discovered that this little mustard plant can tell that the caterpillar is a predator by the vibrations it makes when feeding and in response it creates chemicals to repel the attack. (SOUNDBITE) (English) HEIDI APPEL, SENIOR RESEARCH SCIENTIST AT THE UNIVERSITY OF MISSOURI, SAYING: "We've known for some time that plants can respond to single vibrations or to music, but we haven't known why they do that or how." Researcher Rex Cocroft used specialized lasers to detect the vibrations and measure how much the leaf moved in response to the chewing. (SOUNDBITE) (English) REX COCROFT, PROFESSOR OF BIOLOGICAL SCIENCES AT THE UNIVERSITY OF MISSOURI, SAYING: "My part of the collaboration involves recording the tiny vibrations produced by the caterpillars as they're feeding, analyzing those and reproducing them, playing them back to the plant. And Heidi's part is to look at the way the plant responds chemically to deter those herbivores." They found that the mustard plants ignore vibrations created by nonthreatening insects and wind, yet they create more mustard oils that make caterpillars turn away when the vibration sound of chewing occurs. (SOUNDBITE) (English) HEIDI APPEL, SENIOR RESEARCH SCIENTIST AT THE UNIVERSITY OF MISSOURI, SAYING: "Understanding how plants detect and respond to sounds in their environment gives us new ways to help plants defend themselves against our insect pests. It also opens the window of plant behavior just a little wider, so we see that plants respond to outside influences in their environment in ways that we do, although the exact responses may look a little different." The team continues their research with the hopes of determining the larger impact these vibrations have on agriculture.