Identification of tyrosol in the culture filtrate of Annulohypoxylon truncatum as a mycelial inducer of the Japanese white jelly mushroom Tremella yokohamensis

Abstract

In recent years, Annulohypoxylon species have been gaining much attention for their role as companion fungi in the cultivation of white jelly mushrooms. In the present study, we investigated how Annulohypoxylon truncatum promotes the life cycle of the Japanese white jelly mushroom Tremella yokohamensis by examining its ability to induce the transition from the yeast form to the hyphal form of T. yokohamensis. From the culture filtrate of A. truncatum, we identified 2-(4-hydroxyphenyl)ethanol (tyrosol) as an inducer of mycelial growth. However, while tyrosol initiated germ tube formation, it did not lead to sustained mycelial growth. These findings highlight the complex regulation of T. yokohamensis mycelial growth by multiple compounds produced by A. truncatum.