Trees Make Aspirin When Stressed

Interesting article. It made me think about the series Rome when people were offered "Willow water" when not feeling well.

Plants make aspirin when they need an immune boost, according to new research, sending a form of the compound airborne to signal a health problem to the rest of the tree or to other trees.

The finding may help growers more readily identify plants under stress by monitoring for the airborne distress signal.

Researchers at the National Center for Atmospheric Research in Boulder, Colo. made the finding over a walnut tree grove in California. They used sensitive instruments to detect the organic compounds in the air over the grove at different locations, including different heights.

The researchers found levels of an unidentified compound that swamped the levels of the compounds they set out to look for.

"It was kind of a surprise to us because we weren't really looking for this product," said study lead author Thomas Karl. "We weren't sure what we were seeing to begin with."

The compound turned out to be methyl salicylate, a volatile form of salicylic acid. Salicylic acid was originally derived from willow bark and shown to have the pain- and fever-relieving effects known for aspirin. A modified form of salicylic acid, acetosalicylic acid, is now sold as the active ingredient in aspirin.

Salicylic acid is produced by plants when they are under stress like drought or attack by a fungus or insect. It travels through the plant's vascular system and activates the plant's version of an immune response.

HT Sports Frog