Aspects of photoinduction of carotenogenesis in the fungus Verticillium agaricinum

An action spectrum for light induced carotenogenesis in Verticillium agaricinum (Link) Corda (ATCC 24668) was obtained by exposing mycelial pads to monochromatic radiation. Action maxima occurred at 290 (main peak) and 390 nm, and there was a minor peak at 483 nm. The results also showed interaction between the blue and UV light. Blue light partly reversed the UV light induction of carotenogenesis when given after, but not when given before UV light. This implies that there are at least two photoreceptors involved in carotenogenesis in Verticillium , but phytochrome is not likely to be one of them.