High impact information on CO

• The CONSTANS gene of Arabidopsis promotes flowering and encodes a protein showing similarities to zinc finger transcription factors [1].
• Mutations in elf4 result in early flowering in non-inductive photoperiods, which is probably caused by elevated amounts of CONSTANS (CO), a gene that promotes floral induction [2].
• Like LFY, FT acts partially downstream of CONSTANS (CO), which promotes flowering in response to long days [3].
• A photoperiod-dependent pathway relays signals from photoreceptors to a transcription factor gene, CONSTANS (CO), which activates downstream meristem identity genes such as LEAFY (LFY) [4].
• SOC1 is directly activated by CONSTANS (CO) in long photoperiods and is repressed by FLC, a component of the vernalization (low-temperature) pathway [5].

Biological context of CO

• The CCT (for CONSTANS, CONSTANS-LIKE, TOC1) domain is found in 45 Arabidopsis thaliana proteins involved in processes such as photoperiodic flowering, light signaling, and regulation of circadian rhythms [6].
• Mutagenesis of plants overexpressing CONSTANS demonstrates novel interactions among Arabidopsis flowering-time genes [7].
• Hd1, a major photoperiod sensitivity quantitative trait locus in rice, is closely related to the Arabidopsis flowering time gene CONSTANS [8].
• We isolated and sequenced three genomic regions from diploid Cleome spinosa (Cleomaceae) that are each homoeologous to a duplicated region shared between At3 and At5, centered on the paralogs of SEPALLATA (SEP) and CONSTANS (CO) [9].
• The Arabidopsis thaliana CONSTANS (CO) gene which promotes flowering in long days was recently isolated by chromosome walking [10].

Regulatory relationships of CO

• CONSTANS activates SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1 through FLOWERING LOCUS T to promote flowering in Arabidopsis [11].

Other interactions of CO

• FKF1 F-box protein mediates cyclic degradation of a repressor of CONSTANS in Arabidopsis [12].
• Finally, we found that the GI-dependent promotion of CONSTANS expression and flowering is intact in a gi mutant with altered circadian regulation [13].
• TOC1 shares similarity to the receiver domain of the well-known two-component phosphorelay signalling systems, combined with a strong similarity to a region of the CONSTANS transcription factor, which is involved in controlling flowering time [14].
• The Arabidopsis CONSTANS (CO) gene is a key regulator of the long day (LD)-dependent flowering pathway and two CO homologous genes COL1 and COL2 are involved in the regulation of the circadian rhythm [15].
• Unlike constans, the col3 mutant flowers early and shows a reduced number of lateral branches in short days [16].

Analytical, diagnostic and therapeutic context of CO

• Molecular cloning and expression analysis of a CONSTANS homologue, PnCOL1, from Pharbitis nil [15].

References