Tomato plants defend themselves against infestation by absorbing an odorant emitted by neighboring plants under attack and developing a compound hazardous to the invaders, Japanese researchers have found.
They said they hope the discovery will lead to the development of agrichemicals that take advantage of the self-defense mechanism of plants.
It has been reported that plants go on the defensive when neighboring plants are infested, but the mechanism has been largely unknown.
To uncover the secrets, researchers from Kyoto University and Yamaguchi University examined how undamaged tomato plants react when leaves from nearby tomato plants are attacked by cutworms.
The team, led by Junji Takabayashi, a professor of chemical ecology at Kyoto University, found an increase in the unharmed plants of a specific compound that reduces the survival rate of cutworms by more than 20 percent.
The tomato plants absorbed the odorant from outside, possibly from the nearby damaged leaves, and synthesize it with sugar to produce the poisonous compound, the researchers said.
The odorant is emitted by other plants when they are damaged. It releases a familiar scent that arises when people cut grass and other plants in gardens and fields.
The researchers believe that rice stalks, eggplants, cucumbers and other plants have the same defense mechanism.
Their findings were published online on April 29 in the Proceedings of the U.S. National Academy of Sciences (http://www.pnas.org/content/early/2014/04/23/1320660111.abstract)