Figure 8.—

Simplified model of Arabidopsis photoreceptor function in the light regulation of photomorphogenesis. The cry1, cry2, phot1, phot2, and ZTL/FKF1/LKP2 family of photoreceptors perceive and respond to the blue region of the light spectrum, while phys perceive and respond to all three (blue, red, and far-red) light signals. All five phys perceive and respond to red light signals, while phyA, phyB, phyD, and possibly phyC/phyE respond to blue light signals. phyA is the sole photoreceptor for perceiving and responding to the far-red light signals. phys and crys may function synergistically and/or antagonistically to optimize photomorphogenesis under blue light signals.