A combination of NADHP and hispidin is not essential for bioluminescence in luminous fungal living gills of Mycena chlorophos.

The chemical mechanisms underlying visible bioluminescence in the fungus Mycena chlorophos are not clear. A combination of dihydronicotinamide adenine dinucleotide phosphate (NADPH) and hispidin, which has been reported to increase the intensity of in vitro luminescence in crude cold-water extracts prepared from the bioluminescent fruiting bodies of M. chlorophos, exhibited potential bioluminescence activation in the early bioluminescence stages, in which the bioluminescence was ultra-weak, for living gills and luminescence activation for non-bioluminescent gills, which was collapsed by freezing and subsequent thawing, at all bioluminescence stages. These abilities were not evident in considerably bioluminescent gills. These abilities were blocked by trans-4-hydroxycinnamic acid and trans-3,4-dihydroxycinnamic acid, which were identified as in vivo bioluminescence-activating components. Original bioluminescence and bioluminescence produced from the addition of trans-4-hydroxycinnamic acid and trans-3,4-dihydroxycinnamic acid in living gills were almost completely inhibited by 10 mM NaN , whereas the luminescence produced form the combination of NADPH and hispidin in thawed non-bioluminescent and living gills at the early weak bioluminescence stages was not inhibited by 10 mM NaN . Thus, the combination of NADPH and hispidin plays different roles in luminescence systems compared with essential bioluminescence systems, and the combination of NADPH and hispidin was not essential for visible bioluminescence in living gills.