The photoinduced β-carotene synthesis in is dependent on WC-2A.

β-Carotene, a high value-added natural pigment, is currently produced industrially in . Although photoinduced carotenoid synthesis has been identified in some filamentous fungi, there are still relatively few studies focusing on and its potential mechanisms. In this study, an integrated strategy-including correlation analysis of gene expression, bioinformatics analysis, protein interaction, and RNA interference-was adopted to elucidate photoinduced β-carotene synthesis in . Light wavelength, intensity, and irradiation duration stimulated the transcription of photoreceptors [ () and ()] and carotenoid structural genes ( and ). The transcription of photoreceptor genes showed significant or high correlation with carotenoid structural genes under continuous or short-term, high-intensity blue light irradiation. To elucidate the role of photoreceptors in carotenoid synthesis, the interaction between BTWC-1 and BTWC-2 was predicted. Furthermore, Glutathione S-Transferase (GST) pull-down assays showed that only BTWC-1C and BTWC-2A could interact to form complexes. Inhibition of expression under dark conditions did not affect β-carotene accumulation or the transcription of and , but did reduce these parameters under blue light irradiation, indicating that mediates photoinduced β-carotene synthesis in .