# Surface Tension Propulsion of Fungal Spores

 dc.contributor.author Noblin, Xavier dc.contributor.author Yang, Sylvia dc.contributor.author Dumais, Jacques dc.date.accessioned 2012-11-29T19:59:36Z dc.date.issued 2009 dc.identifier.citation Noblin, Xavier, Sylvia Yang, and Jacques Dumais. 2009. Surface tension propulsion of fungal spores. Journal of Experimental Biology 212(17): 2835-2843. en_US dc.identifier.issn 0022-0949 en_US dc.identifier.uri http://nrs.harvard.edu/urn-3:HUL.InstRepos:9967609 dc.description.abstract Most basidiomycete fungi actively eject their spores. The process begins with the condensation of a water droplet at the base of the spore. The fusion of the droplet onto the spore creates a momentum that propels the spore forward. The use of surface tension for spore ejection offers a new paradigm to perform work at small length scales. However, this mechanism of force generation remains poorly understood. To elucidate how fungal spores make effective use of surface tension, we performed a detailed mechanical analysis of the three stages of spore ejection: the transfer of energy from the drop to the spore, the work of fracture required to release the spore from its supporting structure and the kinetic energy of the spore after ejection. High-speed video imaging of spore ejection in Auricularia auricula and Sporobolomyces yeasts revealed that drop coalescence takes place over a short distance $$(\sim 5 \mu m)$$ and energy transfer is completed in less than $$4 \mu s$$. Based on these observations, we developed an explicit relation for the conversion of surface energy into kinetic energy during the coalescence process. The relation was validated with a simple artificial system and shown to predict the initial spore velocity accurately (predicted velocity: $$1.2 m s^{-1}$$; observed velocity: $$0.8 m s^{-1}$$ for A. auricula). Using calibrated microcantilevers, we also demonstrate that the work required to detach the spore from the supporting sterigma represents only a small fraction of the total energy available for spore ejection. Finally, our observations of this unique discharge mechanism reveal a surprising similarity with the mechanics of jumping in animals. en_US dc.description.sponsorship Organismic and Evolutionary Biology en_US dc.language.iso en_US en_US dc.publisher Company of Biologists en_US dc.relation.isversionof doi:10.1242/jeb.029975 en_US dash.license LAA dc.subject Auricularia auricula en_US dc.subject ballistospores en_US dc.subject wetting phenomena en_US dc.subject spore dispersal en_US dc.subject surface tension en_US dc.title Surface Tension Propulsion of Fungal Spores en_US dc.type Journal Article en_US dc.description.version Version of Record en_US dc.relation.journal Journal of Experimental Biology en_US dash.depositing.author Dumais, Jacques dc.date.available 2012-11-29T19:59:36Z

## Files in this item

Files Size Format View
Noblin_SurfaceTension.pdf 951.7Kb PDF View/Open

Advanced Search