How the protein CCA1 works with RGL1 to control flowering in Arabidopsis plants

CCA1 physically interacts with RGL1, a key repressor in the gibberellin signaling pathway.

• The early-flowering trait in cca1 rgl1-1 double mutants is more pronounced than in single mutants.
• CCA1-OE rgl1-1 plants flower earlier than CCA1-OE alone but later than rgl1-1.
• The CCA1-RGL1 complex is associated with the repression of APETALA1, a master regulator of flower identity.
• Gene expression assays indicate that CCA1 may repress AP1 transcription as part of a regulatory module with RGL1.
• These findings suggest a role for CCA1 in modulating gibberellin-mediated flowering in Arabidopsis.

Simplified