GrassTFDB :: Browse Family::Maize

Displaying C2C2-CO-like Family from Maize


The CO (CONSTANS) gene of Arabidopsis has an important role in the regulation of flowering by photoperiod. CO is part of a gene family with 17 members that are subdivided into three classes termed Group I to III here. All members of the family have a CCT (CO CO-like TOC1) domain near the carboxy terminus. Group I genes which include CO have two zinc finger B-boxes near the amino terminus. Group II genes have one B-box and Group III genes have one B-box and a second diverged zinc finger. Analysis of rice (Oryza sativa) genomic sequence identified 16 genes (OsA-OsP) that were also divided into these three groups showing that their evolution predates monocot/dicot divergence. Eight Group I genes (HvCO1-HvCO8) were isolated from barley (Hordeum vulgare) of which two (HvCO1 and HvCO2) were highly CO like. HvCO3 and its rice counterpart (OsB) had one B-box that was distantly related to Group II genes and was probably derived by internal deletion of a two B-box Group I gene. Sequence homology and comparative mapping showed that HvCO1 was the counterpart of OsA (Hd1) a major determinant of photoperiod sensitivity in rice. Major genes determining photoperiod response have been mapped in barley and wheat (Triticum aestivum) but none corresponded to CO-like genes. Thus selection for variation in photoperiod response has affected different genes in rice and temperate cereals. The peptides of HvCO1 HvCO2 (barley) and Hd1 (rice) show significant structural differences from CO particularly amino acid changes that are predicted to abolish B-box2 function suggesting an evolutionary trend toward a one-B-box structure in the most CO-like cereal genes.

Protein Name
accepted / suggested
Gene Locus Synonym/
Gene Name
Clone in TFome Genome Browser
ZmCOL1 GRMZM2G405368 CONZ1 View in Browser
ZmCOL2 GRMZM2G144346 COL2 pUT5888 View in Browser
ZmCOL3 GRMZM2G021777 COL3 View in Browser
ZmCOL4 GRMZM2G107886 COL4 View in Browser
ZmCOL5 GRMZM2G075562 COL5 pUT3382 View in Browser
ZmCOL6 GRMZM2G013398 COL6 pUT5895 View in Browser
ZmCOL7 AC233888.1_FG002 COL7 pUT6100 View in Browser
ZmCOL8 GRMZM2G114137 COL8 pUT5887 View in Browser
ZmCOL9 GRMZM2G167560 COL9 View in Browser
ZmCOL10 GRMZM2G012717 COL10 pUT6036 View in Browser
ZmCOL11 GRMZM2G095598 COL11 pUT5886 View in Browser
ZmCOL12 GRMZM2G041991 COL12 pUT6195 View in Browser
ZmCOL13 GRMZM2G038783 COL13 pUT5885 View in Browser
ZmCOL14 GRMZM2G042198 COL14 pUT3383 View in Browser