Expression of tyrosinase genes associated with fruiting body formation and pigmentation in Grifola frondosa

Abstract

Chemical and physical properties (including ultraviolet spectrum) of a brown pigment isolated from Grifola frondosa fruiting bodies were almost identical to those of fungal melanin. From the full genome sequence of G. frondosa , genes involved in the melanin biosynthesis pathway of this polypore mushroom were identified, including tyrosinases ( tyr1 and tyr2 ). Transcriptional analyses showed dramatic changes only in the expression of tyr2 in the primordial stage. Immuno-electron microscopy using anti-tyrosinase antibodies showed that TYR2 localizes in the cell walls of primordia. Therefore, TYR2 may be closely associated with melanin biosynthesis in this polypore mushroom G. frondosa , and melanin might be produced in the cell wall. • Brown pigment from Grifola frondosa fruiting bodies was identified as melanin. • We identified tyrosinases tyr1 and tyr2 from the full genome sequence of G. frondosa. • Transcription of tyr2 showed dramatic increase in the primordial stage only. • TYR2 localized in the cell wall of wild-type primordial cells.