关键词: 芜菁, 二氢黄酮醇4–还原酶基因, 启动子, 功能鉴定

Abstract: Based on the gene sequences of dihydroflavonol 4-reductase（DFR）which were cloned from‘Tsuda’and‘Yurugi Akamaru’turnip，the 1 296 and 1 297 bp promoter fragments of BrDFR1 and BrDFR2 genes were obtained from these two turnips’ genome by genome walking method. More cis-acting elements of BrDFR1 and BrDFR2 promoters，such as TATA box，CAAT box，light responsive elements，ABRE，WUN-motif，LTR，TC-rich repeats and MeJA responsive motif，were identified using bioinformatics method. The nucleotide sequences of BrDFR1P and BrDFR2P had 15 differences. The pCAMBIA1301 plant expression vectors containing these two promoter sequence respectively were constructed with the GUS reporter gene，which were called Promoter::GUS vectors，and then transformed into tobacco through the mediation of Agrobacterium tumefaciens. Histochemical staining analysis showedthat the expression of GUS reporter gene could be driven by BrDFR1P and BrDFR2P. A series of 5′-end deleted fragments of these two promoters were constructed，which were fused with GUS gene and then transformed into tobacco. The stain result indicated that the deleted fragments of BrDFR1P and BrDFR2P had relatively active characteristic that could start the expression of GUS gene.

Key words: turnip, dihydroflavonol 4-reductase gene, promoter, functional identification