By recording video at 250,000 frames per second, biologists have shot the first high-speed camera sequences of spores being ejected by fungi. The spores experience accelerations that may be the fastest of any particle known to biology, the researchers report online September 17 in PLoS ONE.
Scientists have long known that certain fungi can pressurize the fluid in their cells and use that ability to shoot spores as far out as possible. Some researchers have photographed the process, but until now no one had been able to watch it in slow-motion, says fungal biologist Nicholas Money of Miami University of Ohio. “The first time we saw these in the lab, I was crying,” Money says. “It was a once-in-a-career moment.”
Money’s team painstakingly searched their footage for some preciously brief events. All the action was concentrated in just a few millionths of a second within sequences four seconds long, Money explains.
Using their videos and also chemical analyses of microscopic droplets of fluid ejected with the spores, the team concluded that some previous, rougher estimates for the spores’ acceleration were excessive. Still, Money says, the spores accelerated faster than any other biological object that he knows of, at around 200,000 g. One g is the normal acceleration due to gravity; 200,000 g is tens of thousands of times the acceleration experienced by astronauts, and about 1,000 times the acceleration of a flea’s takeoff.
The study examines four different species of fungi that grow on dung. These organisms try to send off their spores far enough to potentially land on fresh grass. From there, the spores can be eaten by an animal and begin a new life cycle.
Money says that the high-speed camera method could also shed light on how indoor molds release spores, which cause serious allergic reactions in people.
Fast-Flying Fungal Spores from Science News on Vimeo .
