Abstract
Circadian clock components, LHY, CCA1, TOC1 and GI, are thought to compose a negative feed-back loop to control their expression reciprocally in Arabidopsis. Loss-of-function of both LHY and CCA1 causes acceleration of flowering under short days (SD). GI expression peaks in the morning in the lhy cca1 double mutants, although it normally does in the evening in wild-type. GI gene is required for the early flowering phenotype of lhy cca1 under SD. These results suggest that the early flowering phenotype of lhy cca1 may be caused by mis-expression of GI. It is reported that CO, a downstream factor of GI, promotes flowering through two floral activators, FT and SOC1. To understand molecular mechanisms how clock components control flowering, we have generated multiple mutants on circadian rhythms and flowering time regulation. Here we report genetic analysis of interactions among clock components, LHY and CCA1, and floral inducers, CO, FT and SOC1.
