Master Blaster Fungus

November 30, 2005



The fungus Gibberella zeae

Here's the latest from the Department of Stuff That's Neat to Know: An infinitesimal corn fungus has been found to be nature's most powerful known cannoneer. It blasts its spores out at 870,000 times the force of gravity, about ten times the acceleration of a rifle bullet.

Working with colleagues at Michigan State University, Duke biologist Steven Vogel, a longtime aficionado of nature's mechanisms, figured out the acceleration of spores of the fungus Gibberella zeae. The researchers published their findings in the June issue of Fungal Genetics and Biology.

Fear not: The fungal super gun poses no danger to farmers or corn shuckers. Vogel explains that the tiny fungus lives in a different physical realm from humans. In the fungal Lilliputian world, atmospheric drag is enormous. Hence, the fungal spores travel only about two-tenths of an inch--five millimeters--before falling. "To get a literal feel for a world in which drag makes more impact than does gravity, just inflate a six-inch balloon and throw it as hard as you can," says Vogel.

The researchers measured the fungal "bioballistics" in experiments to better understand the biological mechanism behind such a powerful blast. They found that the fungus uses the osmotic pressure of a salt solution inside its launch chamber to build up the necessary pressure.

"Given the short range of its spores, why bother accelerating to eighty miles per hour to go a mere five millimeters?" Vogel asks.

The answer, my friend, is blowin' in the wind: "Since there is almost no air movement at the surface where the spore grows, the real object of the launch is to get the spore even a little ways from the parent, so that it can get into air currents, which will really give the spore some range," he explains.