Give Now  »

Noon Edition

How Plant Communication And Your Allergies Are Related

Hay fever and allergies may seem like a senseless waste of the finest time of year. But those same chemicals that start you sneezing act as a kind of chemical communication between plants.


We usually think of communication as involving words or gestures. In fact, chemicalsand especially proteinsare used by both animals and plants to communicate all the time.

For example, when you get a sudden scare, your mind sends a chemical message to the heart telling it to speed up.

Identifying Plants

Every pollen grain contains a protein molecule whose only function is to help it identify plants of the same species. And every flower has a protein, unique to that species, whose only function is to help it identify pollen of the right species.

When pollen lands on a plant of its own species, the two proteins interact, and initiate the process which will ultimately produce seeds. The protein molecules aren't actually involved in producing seeds, but their interaction is the go-ahead signal for the process to begin.

Since these proteins only interact with proteins from the same species, nothing happens when pollen lands on a plant of a different species.

But Why Should Pollen Produce Cold-symptoms In Some People?

As suggested earlier, animals also send and respond to proteins. When cold viruses enter your nose, your body activates its immune system in response to a protein coating on the virus.

The next thing you know you've got a stuffed up head, your nose is running, and you're home from work. It's annoying, but that's how we fight infection.

For some reason, the proteins in pollen produce the same immune response in some people. There are no viruses to destroy, but the protein is there and the body responds.

Why Do I React And My Friend Doesn't?

No one really knows why some people react to pollen and others don't or why certain species affect certain people, but for those who are affected, the chemical communication between plants is less than enlightening.

Support For Indiana Public Media Comes From

About A Moment of Science