The Transcription Factor COL12 Is a Substrate of the COP1/SPA E3 Ligase and Regulates Flowering Time and Plant Architecture.

The ambient light environment controls many aspects of plant development throughout a plant's life cycle. Such complex control is achieved because a key repressor of light signaling, the Arabidopsis () COP1/SPA E3 ubiquitin ligase causes the degradation of multiple regulators of endogenous developmental pathways. This includes the CONSTANS (CO) transcription factor that is responsible for photoperiodic control of flowering time.