Poison Ivy Solving a Mystery
ambience: Dawn Chorus
Researchers trying to grow Poison Ivy in a lab discovered that mysteriously all their seedlings would be destroyed by a fungus. I’m Jim Metzner and this is the Pulse of the Planet.
Jelesko: And we began to ask ourselves the question, why would poison ivy plants harbor a fungus that would kill the seedlings of the next generation?
John Jelesko is an associate Professor in the Department of Plant Pathology, Physiology, and Weed Science at Virginia Tech. He and his team had figured that the relationship between the fungus and the poison had evolved to kill any poison ivy seeds that might fall near a poison ivy plant to avoid unwanted crowding and competition from new plants. But then, how would the poison ivy seeds ever grow?
Jelesko: what was a good clue was the fact that the seeds needed some sort of acid treatment in order for them to germinate. At this point, we realized that birds, during the fall and winter, eat a lot of poison ivy seeds and that led us to speculate that a migrating bird will come and eat a poison ivy seed that has this fungus on it, and then, as it passes through the bird’s gut called the gizzard that contains sand that the birds will eat. Poison Ivy seeds get ground up like a food processor. And what we think happens is the fungus will get stripped off the outer part of the seed, allowing the seed now to go further down in the bird’s gut, where it encounters a lot of acid. And now the acid treatment will help get rid of any residual fungus but also prime the seed to be ready to germinate after the bird passes it someplace further away from where it was originally eaten.
We’ll hear more about Poison Ivy in future programs. I’m Jim Metzner and this is the Pulse of the Planet.