In the dark, the maximum absorption of the FMN chromophore is around 450 nm.
Blue light induces the formation of a covalent bond between FMN and a cysteine residue, shifting the absorption maximum to 390 nm via a LOV660 intermediate form. The reaction is reversible in darkness.
#Unit 6. System Physiology – Plant#Blue-Light Responses and Photoreceptors#Part B Pointers
