荔枝DFR基因的克隆及其序列分析

Cloning and sequence analysis of DFR gene from litchi

采用同源克隆的方法从荔枝果皮中克隆得到一个二氢黄酮醇4-还原酶(DFR)基因,该基因开放阅读框全长1062 bp,编码353个氨基酸.基因组扩增得到长度为2321 bp的片段,分析发现:该基因含有5个内含子,分别在119-255、426-1158、1353-1470、1632-1819、2013-2095 bp之间.通过系统发育分析发现,该基因编码的蛋白与山葡萄、海棠和山竹子等果树具有较近的亲缘关系.

The dihydroflavonol 4-reduetase （DFR） was a key enzyme in the anthocyanin biosynthesis. Degenerate primers designed according the conservative domain of dihydroflavonol 4-reductase （DFR） in plants were used to amplify the DFR fragments from the cDNA of litchi （Litchi chinensis Sonn. ）. A full length sequence of DFR gene was cloned from litchi pericarp by RACE （rapid-amplification of eDNA ends） method. The open reading frame of lltchi DFR gene was 1062 bp, and encoding 353 amino acids. The 2321 hp length fragment was amplified from genome of litchi, which contained five introns respectively, in 119 -255,426 -1158, 1353 - 1470, 1632 - 1819, 2013 -2095 bp. It was found that the amino acid sequence of litchi DFR gene had closer relationship with mountain grape （Vitis amurertsis）, begonia （Ma/us hybrid cultivar） and mangosteen （Garcinia mangostana） through phylogenetic analysis.