LISTENING IN ON PLANT TALK.

Byline: Laura Beil Dallas Morning News

It may not be audible, but scientists have recently discovered that plants can signal one other to upcoming danger.

It seems that oil of wintergreen, a volatile compound made by many plants, may act as an airborne signal that can alert the neighboring plant to activate genes that help give it resistance to disease.

Researchers from Rutgers University in New Jersey inoculated a group of tobacco plants with tobacco mosaic virus and discovered that the infected plants released an airborne form of oil of wintergreen. To figure out the role of the substance, the researchers incubated plants in airtight chambers and pumped in the gaseous compound.

They discovered that the cells in the plants' leaves, after exposure to the gas, had developed some resistance to the virus. The oil of wintergreen had altered the genetic coding of the leaves.

The researchers then connected two airtight containers of plants; one contained infected plants and the other did not. After six days, the plants that shared only the same air with their infected brethren had developed resistance to the virus.

``To our knowledge,'' the scientists reported last month in the journal Nature, the wafting wintergreen ``is the first airborne signal to be shown to be involved in communication between infected and healthy plants.''