Evolution, Ecology, Symbiosis, Plants, Fungi, Insects
Retired from lab research, I continue to develop the hypothesis that terrestrial fungi express a conserved intracellular protoplast phase as part of their endophytic life cycle within plants.
My interest in fungi evolved from a plant question: how and why numerous plant lineages independently evolved the ability to parasitize other plants via similar tumor-like structures called haustoria.
I considered the possibility that a common genetic denominator might be symbiotic microbes that facilitate their own transmission by influencing haustoria formation. However, ultrastructural studies failed to locate candidate microbes within the tumor-like tissues.
Late in my career I macerated the plant-connecting tissues in liquid media, assuming that cryptic intracellular symbionts might be released from biochemically compromised plant cells. The organisms that appeared were fungus cells that seemed to have no precursors, but were finally traced to the minute bodies I call mycosomes (Atsatt 2003
; Atsatt & Whiteside 2014
It soon became evident that cultured mycosomes were transforming into endophytic fungi, i.e., ecologically and phylogenetically diverse terrestrial fungi that are now viewed as ubiquitious plant symbionts. I am currently preparing two baseline papers that characterize mycosome developmental states, and provide testable hypotheses that begin to explain mycosome structure, function and evolution.