Fungal Symbiosis: The Fascinating World of Fungal Mutualistic Relationships Fungal Symbiosis is a branch of mycology that focuses on the study of the relationships between fungi and other organisms. In particular, it delves into the mutually beneficial partnerships formed between fungi and their counterparts, be it plants, animals, or other fungi. Symbiosis, from the Greek words “sym” meaning together and “biosis” meaning life, refers to a close and often long-term interaction between two different organisms.