Passage V

Giant puffball mushrooms (GPMs) have belowground and aboveground structures. Below ground, tubelike threads called hyphae extend throughout the soil. Aboveground, the visible portion of the GPM is referred to as a basidiocarp. When some GPMs are disrupted, such as when they are stepped on by an animal, a cloud of particles resem­bling smoke is released from the basidiocarp. Two students discuss the function of the hyphae and basidiocarps in GPMs and also discuss the contents of the cloud of parti­cles released when the basidiocarp is disrupted.

Student 1

The basidiocarps of GPMs are reproductive structures. When cells in the basidiocarp are mature, they produce, by meiosis, cells called spores. The spores are stored directly below the surface of the basidiocarp until the basidiocarp is disrupted. After release, a spore may settle in the soil, ger­minate, and then form a new hypha. When a newly formed hypha meets another newly formed hypha, they fuse and then produce a new basidiocarp. Young basidiocarps do not yet contain spores and thus do not produce a cloud of parti­cles when disrupted.

The hyphae of a GPM acquire nutrients for the organ­ism from organic matter in the soil. The nutrients are then transported to feed the aboveground structure.

Student 2

The hyphae of GPMs are reproductive structures, sim­ilar to the roots of some plants that reproduce asexually. To produce a new GPM, the hyphae grow away from the parental GPM to another location in the soil. Once the hyphae have grown away from the parental GPM, the hyphae produce a new basidiocarp. After the new basidio­carp has formed, the newly grown hypbae separate from the parental hyphae.

Like the leaves of plants, the basidiocarps of GPMs produce energy for the organisms through the process of photosynthesis. Basidiocarps also function as deterrents to predators by releasing a cloud of particles comaining toxins when disrupted. Young GPMs do not yet produce toxins and are thus unable to release a cloud of particles.