The fastest flights in nature: High-speed spore discharge mechanisms among fungi

September 17, 2008

Microscopic coprophilous or dung-loving fungi help make our planet habitable by degrading the billions of tons of feces produced by herbivores. But the fungi have a problem: survival depends upon the consumption of their spores by herbivores and few animals will graze on grass next to their own dung. Evolution has overcome this obstacle by producing an array of mechanisms of spore discharge whose elegance transforms a cow pie into a circus of microscopic catapults, trampolines, and squirt guns.

A new paper from Nik Money's lab at Miami University in Oxford, Ohio, in collaboration with Diana Davis and Mark Fischer at the College of Mount St. Joseph in Cincinnati, is published in the open-access journal PLoS ONE and solves the operation of squirt guns that fire spores over distances of more than 2 meters.

The researchers used high speed cameras running at up to 250,000 frames per second to capture these blisteringly fast movements. Spores are launched at maximum speeds of 25 meters per second–impressive for a microscopic cell–corresponding to accelerations of 180,000 g. In terms of acceleration, these are the fastest flights in nature.

The paper is significant for a number of reasons. This is the first study utilizing ultra-high-speed video cameras to capture the events of spore discharge in ascomycete and zygomycete fungi. Previous investigators relied upon models to predict ballistic parameters and produced erroneous estimates of velocities and accelerations. These estimates were then used to suggest that pressures within the spore guns were very high. Fungal cells generate pressure by osmosis and, in the PLoS ONE study, the authors used a combination of spectroscopic methods to identify the chemical compounds responsible for driving water influx into the guns.

These experiments showed that the discharge mechanisms in fungi are powered by the same levels of pressure that are characteristic of the cells that make up the feeding colonies of fungi. Therefore, the long flights enjoyed by spores result not from unusually high pressure, but from the way in which explosive pressure loss is linked to the propulsion of the spores. There appear to be some similarities between the escape of the spores and the expulsion of ink droplets through nozzles on inkjet printers.

Another important aspect of the new work is the way that it has allowed the researchers to test different models for the effect of viscous drag on microscopic particles and identify limitations in previous approaches to modeling. This information is very important for future biophysical studies on spore and pollen movement, which have implications for the fields of plant disease control, terrestrial ecology, indoor air quality, atmospheric sciences, veterinary medicine, and biomimetics.

Citation: Yafetto L, Carroll L, Cui Y, Davis DJ, Fischer MWF, et al. (2008) The Fastest Flights in Nature: High-Speed Spore Discharge Mechanisms among Fungi. PLoS ONE 3(9): e3237. doi:10.1371/journal.pone.0003237 dx.plos.org/10.1371/journal.pone.0003237

Source: Public Library of Science

Explore further: Research advances on transplant ward pathogen

Related Stories

Research advances on transplant ward pathogen

August 28, 2015

The fungus Cryptococcus causes meningitis, a brain disease that kills about 1 million people each year—mainly those with impaired immune systems due to AIDS, cancer treatment or an organ transplant. It's difficult to treat ...

Dual internal clocks keep plant defenses on schedule

June 22, 2015

Time management isn't just important for busy people—it's critical for plants, too. A Duke University study shows how two biological clocks work together to help plants deal with intermittent demands such as fungal infections, ...

The winner doesn't always take all

June 11, 2015

Theoretically predicted and now demonstrated experimentally for the first time using soil bacteria: weaker organisms can prevail against stronger ones—if they are superior in number. This acts as a driving mechanism in ...

Recommended for you

Parasitized bees are self-medicating in the wild, study finds

September 1, 2015

Bumblebees infected with a common intestinal parasite are drawn to flowers whose nectar and pollen have a medicinal effect, a Dartmouth-led study shows. The findings suggest that plant chemistry could help combat the decline ...

How wind sculpted Earth's largest dust deposit

September 1, 2015

China's Loess Plateau was formed by wind alternately depositing dust or removing dust over the last 2.6 million years, according to a new report from University of Arizona geoscientists.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.