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Plants Smell Danger

January 16, 2013

A type of plant can sense mating chemicals from fruit flies, and builds up its defenses when it does.



Plants that sniff out threats.  I’m Bob Hirshon and this is Science Update.

Male fruit flies use chemical odors to attract mates. But to plants called goldenrods, these amorous scents spell danger. That’s because after the flies mate, the females lay their eggs in the goldenrod’s stem, damaging the plant. Penn State University entomologist Mark Mescher and his colleagues found that goldenrod plants can actually detect the fruit fly smell. And when they do, they build up their defenses accordingly.

MARK MESCHER (The Pennsylvania State University):

So the plant is actually producing toxins and so forth, that are defending itself to the herbivores, and we can see that that’s stronger in plants that have previously been exposed to this odor.

It’s already known that some plants can detect distress chemicals from nearby plants that are being attacked by insects. But this is the first time a plant’s been shown to respond to a chemical from the enemy itself.  I’m Bob Hirshon for AAAS, the Science Society.

The tall goldenrod plant may be able to "smell" pests and prepare defenses to ward off attacks. (Pennstatelive/Flickr)