Functional and evolutionary characterization of the CONSTANS gene family in short-day photoperiodic flowering in soybean.
CONSTANS (CO) plays a central role in photoperiodic flowering control of plants. However, much remains unknown about the function of the CO gene family in soybean and the molecular mechanisms underlying short-day photoperiodic flowering of soybean. We identified 26 CO homologs (GmCOLs) in the soybean genome, many of them previously unreported. Phylogenic analysis classified GmCOLs into three clades conserved among flowering plants. Two homeologous pairs in Clade I, GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b, showed the highest sequence similarity to Arabidopsis CO. The mRNA abundance of GmCOL1a and GmCOL1b exhibited a strong diurnal rhythm under flowering-inductive short days and peaked at dawn, which coincided with the rise of GmFT5a expression. In contrast, the mRNA abundance of GmCOL2a and GmCOL2b was extremely low. Our transgenic study demonstrated that GmCOL1a, GmCOL1b, GmCOL2a and GmCOL2b fully complemented the late flowering effect of the co-1 mutant in Arabidopsis. Together, these results indicate that GmCOL1a and GmCOL1b are potential inducers of flowering in soybean. Our data also indicate rapid regulatory divergence between GmCOL1a/GmCOL1b and GmCOL2a/GmCOL2b but conservation of their protein function. Dynamic evolution of GmCOL regulatory mechanisms may underlie the evolution of photoperiodic signaling in soybean.
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Faqiang
F
Wu
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Brian William
BW
Price
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Waseem
W
Haider
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Gabriela
G
Seufferheld
USDA-Agricultural Research Service, Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Randall
R
Nelson
Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America.
Yoshie
Y
Hanzawa
D000483:Alleles; D017360:Arabidopsis / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics; D002940:Circadian Rhythm / Q000235:genetics; D016000:Cluster Analysis; D017124:Conserved Sequence / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D019143:Evolution, Molecular; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D056426:Genetic Loci / Q000235:genetics; D005838:Genotype; D007178:Inbreeding; D005810:Multigene Family; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D017440:Photoperiod; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017423:Sequence Analysis, RNA; D012689:Sequence Homology, Nucleic Acid; D013025:Glycine max / Q000235:genetics* / Q000502:physiology*; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics
D029681:Arabidopsis Proteins; C092776:CONSTANS protein, Arabidopsis; D004268:DNA-Binding Proteins; D010940:Plant Proteins; D012333:RNA, Messenger; D014157:Transcription Factors