The "dark magic mushroom" co-produces amatoxins and psilocybin

Area of Science:

• Mycology
• Biochemistry
• Evolutionary Biology

Background:

• Mushrooms produce famous compounds like psilocybin (psychedelic) and amatoxins (toxic).
• These compounds are found in diverse fungal lineages but not within the same species.
• The co-occurrence of these distinct chemical systems in one species was previously unknown.

Purpose of the Study:

• To investigate the co-occurrence of psilocybin and amatoxins in a single fungal species.
• To identify the biosynthetic pathways and evolutionary origins of these compounds in Galerina indica.
• To understand the implications of combining potent bioactive systems within one species.

Main Methods:

• Mass spectrometry was used to detect psilocybin and amatoxins in mushroom tissues.
• Genomic analyses were performed to identify the genes responsible for biosynthesis.
• Phylogenetic analyses were conducted to infer the evolutionary history of the biosynthetic genes.

Main Results:

• Galerina indica was confirmed to produce both psilocybin and amatoxins.
• Biosynthetic genes for both compounds were identified in the G. indica genome.
• Phylogenetic analyses indicated horizontal gene transfer of psilocybin biosynthesis into Galerina, occurring after amatoxin biosynthesis was established.
• Psilocybin biosynthesis appears to have been acquired independently multiple times within the Galerina genus.
• The acquisition of psilocybin biosynthesis may correlate with decreased amatoxin potency in G. indica.

Conclusions:

• Horizontal gene transfer can facilitate the combination of complex bioactive compound systems within a single species.
• The co-occurrence of psilocybin and amatoxins in G. indica demonstrates a novel evolutionary mechanism.
• This combination could alter the ecological roles of these compounds and impact the evolutionary fitness of the fungus.