Fungal spore discharge and dispersal in the atmosphere
INPhyNY, CNRS, Nice
Fungi range from decomposers to symbionts, parasites and pathogens and are among the worst threats and at the same time the most fundamental components of many ecosystems. The fungi may lack legs or wings for locomotion, but they routinely translocate even across oceans by dispersing their spores, causing the spread of major diseases of crops, animals and humans. Most fungi use a spectacular discharge mechanism based on osmotic pressure to accelerate spores at rates nearly unmatched elsewhere in nature. I will show that these fungal cannons are optimized to the slimmest level of precision, using theoretical models and data analysis. Despite impressive accelerations, inertia may fall short in sailing the spores across the boundary layer surrounding the fungus. I will discuss a collective mechanism of discharge that manipulates the fluid flow around the fungus to disperse spores much further than they would go in isolation. Once the spore is out in the air, its trajectory is affected by a series of stochastic events unknown to the fungus. I will conclude with some preliminary results and open questions on how fungi face uncertainty and the potential strategies for spore liberation.