Fungal Launchers: The Biophysics of Active Fungal Spore Discharge

Energy-powered spore-launching strategy is an evolved feature of many fungal species, facilitating dispersal into the surrounding environment, thereby contributing to reproductive success and completing their life cycle. With a focus on the underlying biophysical principles and their broader implications for fungal ecology, this review explores current knowledge of spore discharge biomechanics across different fungal groups. Additionally, it discusses how each step of spore launching relates to fundamental physical principles of energy and motion. Literature was collected through iterative searches in Web of Science and Google Scholar. Additional documents were retrieved through manual searches of key publications’ reference lists and citation tracking. The widely investigated fungal groups regarding spore launching include sporangia squirters (like Pilobolus), ballistospore catapulters (like Agaricus), and ascospore launchers (like Neurospora). Osmotic pressure, surface tension, and cavitation are among the major energy-generating mechanisms responsible for propelling spores at extreme acceleration, thus enabling spores to travel distances of up to several meters. Spore discharge mechanisms can be categorized based on how energy is generated, stored, and transformed into mechanical motion. Thanks to advances in biophysical modeling and high-speed imaging, the century-old mystery of fungal launching strategies has been understood to involve principles of fluid mechanics, optics, and projectile dynamics by investigating many fungal groups.