In plants, flowering is triggered by endogenous and environmental signals,
CONSTANS (CO) promotes flowering of Arabidopsis in response to day length.
Four early target genes of CO were identified using a steroid-inducible ver
sion of the protein. Two of these genes, SUPPRESSOR OF OVEREXPRESSION OF CO
1 (SOC1) and FLOWERING LOCUS T (FT), are required for CO to promote flower
ing; the others are involved in proline or ethylene biosynthesis, The SOC1
and FT genes are also regulated by a second flowering-time pathway that act
s independently of CO. Thus, early target genes of CO define common compone
nts of distinct flowering-time pathways.