Abstract:Seed hairs in carrot negatively affect the germination of carrot seeds, and they were necessary to be removed by mechanical or manual approaches before sowing. The development of seed hairs has been shown to be relevant to the regulation mechanism of transcription factor DcTTG1. In this study, we analyzed the genomic and transcriptional variation of DcTTG1 in a seed-hairless carrot genotype (named: ‘Wuye-hairless’), which was identified from the wild carrot germplasm ‘Wuye’ in Hongshan district of Wuhan city. In both genotypes ‘Wuye’ and ‘Wuye-hairless’, DcTTG1 contained an open reading frame with a length of 1011 bp, encoding for 336 amino acid residues. Three amino acid substitutions caused by three nucleotide mutations were observed between two genotypes. By bioinformatic analysis, the deduced DcTTG1 protein sequence contained four WD-40 motifs in both genotypes.The cluster analysis showed that the DcTTG1 of carrot and other TTG1 of Apiaceae plant were clustered in same branch. The transcriptional level of DcTTG1 in ‘Wuye’ was significantly higher than ‘Wuye-hairless’ in the stem, leaf and 5 d after pollination of flowers, while no significant difference was observed at the stages of un-pollinated flowers and seeds formation (20 d after pollination).