2 August 1998
Aspirin Stops Plants Complaining

When plants are attacked or damaged the chemical processes inside the plant go to red alert to address the situation. In the case of insect attack, plants produce specific compounds that produce insect gastro-intestinal distress. These defense compounds are triggered by a hormone, jasmonic acid, which acts like a shot of pain, kick-starting the plants defenses. But new research shows that just as aspirin can stop pain in animals, it can also stop the pain response in plants, suppressing their defensive response to attack.

The results of the research, published in the July issue of The Journal of Biological Chemistry, demonstrate that the formation of jasmonic acid can be blocked by that wonder-drug of the twentieth-century, aspirin. The study was authored by plant biologists Zhiqiang Pan of Arizona State University; Bilal Camara of the Institut de Biologie Moleculaire des Plantes, Strasbourg, France; Harold W. Gardner of the United States Department of Agriculture; and Ralph A. Backhaus of Arizona State University.

The function of aspirin in animals is to block the production of prostaglandin, which triggers swelling and pain. Aspirin binds to the active site of the enzyme that is critical to producing prostaglandin. "It essentially renders the enzyme dead and prevents prostaglandin from building up and creating a reaction," said researcher Backhaus. In plants, aspirin blocks the production of jasmonic acid by similarly binding a critical enzyme. "Jasmonic acid is a hormone that is made when plants are in distress. It signals the production of plant-defense compounds -- it works a little like a shot of pain, warning the plant that it is under attack. It can also volitalize and warn nearby plants, a chain reaction that's like a warning signal to other plants," he added.

But unless you're a locust or aphid that wants to turn off the "neighbourhood burglar alarms" it's difficult to see what benefit turning-off a plant's defense mechanisms would have. Perhaps we'll have to wait for The Day of the Triffids to arrive to really make use of it.

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