基于本实验室已获得的蛇足石杉转录组数据，获得一个编码1-脱氧-D-木酮糖-5-磷酸还原异构酶（1-deoxy-D-xylulose-5-phosphate reductoisomerase，DXR）的转录本，分析其开放阅读框序列，发现该转录本编码全长为1 440 bp 的蛇足石杉DXR 基因（HsDXR1），含有479 个氨基酸残基。采用RT-PCR 方法获得了HsDXR1 全长，并对HsDXR1 编码蛋白的理化性质、结构域及三维结构进行预测分析。结果显示HsDXR1 编码蛋白的预测分子量为51.496 1 kDa，等电点为6.44；不含信号肽和跨膜区；亚细胞定位预测表明该蛋白最可能定位于叶绿体；具有DXR 蛋白典型的结构域。实时荧光定量PCR 检测HsDXR1 基因在蛇足石杉的茎中表达量最高，其次为根，在叶中表达量最低。本研究获得了蛇足石杉HsDXR1 基因的编码区序列，为进一步研究HsDXR1 在蛇足石杉萜类化合物生物合成途径中的功能奠定基础。

The transcript encoding 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) was discovered from the transcriptome data of Huperzia serrata. The transcript contained an open reading frame with length of 1,440 bp and coded 479 amino acids. The full length of HsDXR1 had been cloned using RT-PCR method. According the bioinformatic analysis, the molecular weight of HsDXR1 protein was 51.4961 kDa and the pI was 6.44. No signal peptide and transmembrane site was discovered in HsDXR1, and the protein was most likely to be located in chloroplast. HsDXR1 had the same domain similar to the DXR protein of Arabidopsis and Oryza sativa. The expression level of HsDXR1 was most abundantly in H. serrata stem, followed by root and leaf. This study cloned and analyzed HsDXR1 gene from H. serrata for the first time. The result will provide a foundation for exploring the mechanism of terpene biosynthesis in H. serrata plants.

国家自然科学基金委青年科学基金项目（30900113）：基于宏量ESTs 的蛇足石杉转录组分析及石杉碱甲合成酶（HAS）基因的鉴定研究，负责人：罗红梅；教育部长江学者和创新团队发展计划（IRT1150）：中药资源学，负责人：陈士林。