种子有刺毛与无刺毛胡萝卜转录因子DcTTG1的分离及表达分析

Isolation and Expression of Transcription Factor DcTTG1 in Seed Hairy and Hairless of Carrot

胡萝卜种子中刺毛严重影响胡萝卜播种质量。在胡萝卜播种前需要将种子上的刺毛用机械或者人工方法去除。转录因子TTG1(TRANSPARENT TESTA GLABRA 1)是调节植物刺毛发育的主要因子之一,而在胡萝卜中未有研究报道。本研究报道一种从武汉洪山区野生胡萝卜(武野)中,筛选到植株、茎叶及种子均无毛的材料(命名为:武野-无毛),并对其毛发育调节转录因子DcTTG1进行研究。结果表明,武野和武野-无毛材料的DcTTG1长度均为1011 bp,均可编码336个氨基酸残基。两个材料的DcTTG1序列上有3个位置不同,导致其推导的氨基酸有3个位点不同。两个材料DcTTG1蛋白序列,均含有4个WD-40基序。以拟南芥为外群,进化分析上胡萝卜的DcTTG1与其他伞形科的TTG1处在同一分枝上,其他科植物的TTG1也处在同一分枝上。表达分析表明,DcTTG1在武野材料中的茎、叶及授粉5 d的花,表达量显著高于武野-无毛,但在未授粉花及形成的种子(授粉20 d)不存在显著性。

Seed hairs in carrot negatively affect the germination of carrot seeds.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:Wuyehairless),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).