Cooperation in Fungal Spores
Suppose you were a microscopic fungal spore, and your success was dependent upon making your way to some far off place away from your parent organism, to begin a new life all your own. Maybe you are a pathogen (such as Sclerotinia sclerotiorum) and can only survive if you go off on your own and find a new host to infect. What if you could coordinate with thousands of other spores like you, and in one synchronized ejection effort you could create an air current that would take many of you upward into the flowing air above? Turns out if you belonged to certain fungi, you could do just that. As amazing as microbes are, we don’t often think of them as having behaviors that are coordinated to the second and visible to the naked eye, but some of them do! Check out the embedded video (courtesy of New Scientist) below for an awesome example of this recently investigated phenomena.
The authors of this new study published in the Proceedings of the National Academy of Sciences (PNAS) entitled “Dispersal of fungal spores on a cooperatively generated wind” state the following:
“Here we show that by synchronizing the ejection of thousands of spores, these fungi create a flow of air that carries spores through the nearly still air surrounding the apothecium, around intervening obstacles, and to atmospheric currents and new infection sites.”
These authors come from mathematics, engineering and biology departments, and as you might expect, they used multiple lines of inquiry in this paper. Additionally, they investigated several different species of fungi that eject spores in a coordinate way, and found similar patterns in how they coordinate. The methods included high-speed photography, complex mathematical modeling, laboratory manipulations, and applying ecological theory to their data and models. It turns out that the range of a cooperating spore can be 20 times greater than a spore that ejects on its own. However, it doesn’t benefit all the spores equally. If you are too early or too late in ejecting you don’t catch the ride, and it take many spores to initially generate the flow that triggers all the others, and those initial launchers don’t get much of a ride themselves. In the end, the end result is that some of the spores get jettisoned up into the air, and end up much further away than they would have without the coordinated activity. Apparently these jets of fungal spores can even move around obstacles. This is certainly an important piece of fungal dispersal ecology. In very practical financial terms this study is important for agriculture, since some of the species engaging in this dispersal behavior are important plant pathogens, and understanding that dispersal could help prevent crop infection.
The extent to which microbes in the environment are able to disperse is a huge factor in their geographic arrangement. Here I group bacteria and archaea together with fungal spores because their size means their dispersal is fundamentally different from larger organisms. Microbial dispersal is something that is difficult to study, and, therefore, not well understood. Better information about of how these organisms get around, and how far they can travel will come out of more interdisciplinary studies such as this one, and is needed in order to understand the ecology of microbes.
Roper M, Seminara A, Bandi MM, Cobb A, Dillard HR, & Pringle A (2010). Dispersal of fungal spores on a cooperatively generated wind. Proceedings of the National Academy of Sciences of the United States of America PMID: 20880834