As fungi grow, they constantly perceive, learn and make decisions. Fungi are like polyglots: they both “speak” and understand a wide variety of chemical signals. They release and react to chemicals that float in the air and flow in the water. Interestingly, fungi not only perceive the meaning of a chemical, but must also interpret it in context and in relation to other chemicals.
Studies of how fungi interact have lagged behind research on plant and especially animal interactions. Most are based on multiple species of “lab mice”, so knowledge of other species is limited, but here we summarize what is known about three areas of interaction: within fungi, between fungi of the same species, and with other organisms.
In the fungus
Each growing tip has autonomy and responsibility for the whole organism, similar to the social insect and its relationship to the hive. Chemicals, nutrients, and electrical impulses flow between the cells in each mycelium. Their activities work to communicate information about events and coordinate actions across the network. Research by Andrew Adamatzky, professor of abnormal computing at the University of the West of England in Bristol, suggests that they can affect the internal bioelectrical signals of the mycelium, which can create “language”. Whether or not mycelium is a nervous system, mycelium has similarities to these systems. Both have branching structures, strengthen or shorten pathways as needed, and use some of the same amino acids to transmit information.
Among fungi of the same species
Many fungi are sexual and must mate to reproduce. They send out pheromones and “smell” others and then grow into attractive ones (based on what they are attracted to). Whenever two mycelia meet, they meet to negotiate their relationship, which can range from fusion (to form a reproductive or reproductive partnership) to physical isolation to indifference or even chemical antagonism. Each associated mycelium negotiates the physical dynamics of fusion and life thereafter through association.