Genetic and molecular analysis of the late flowering phenotype of lhy cca1 under continuous light condition

Abstract

LHY, CCA1, TOC1 and GI have been shown to be closely associated with a clock function in Arabidopsis. Loss-of-function of both LHY and CCA1 causes an acceleration of flowering under short days (SD). The early flowering phenotype of lhy cca1 correlated with 1) a phase shift of GI, 2) a phase shift of CO and 3) up-regulation of FT under SD. Based on the results, we proposed that LHY and CCA1 may control flowering mainly through a transcriptional cascade "GI-CO-FT". Recently, we have found that lhy cca1 showed late flowering phenotype under continuous light condition and the phenotype was not recovered by temperature cycles. The late flowering phenotype was not explained simply by mis-expression of GI and CO. Here we report genetic and molecular analysis of the late flowering phenotype of lhy cca1.