目的 克隆荆芥1-脱氧-D-木酮糖-5-磷酸合成酶（1-deoxy-D-xylulose 5-phosphate synthase，StDXS）基因，并进行生物信息学分析。方法 根据荆芥转录组数据获得的StDXS基因序列设计特异性引物，通过RT-PCR技术获得StDXS基因cDNA的全长序列，并进行生物信息学分析。结果 荆芥StDXS基因全长2177 bp，包含一个长度为2157 bp的开放阅读框，编码718个氨基酸，其理论相对分子质量为77 240，等电点为6.32，定位于叶绿体，不存在跨膜区及信号肽，为非分泌蛋白。同源系统进化树分析表明，该序列与同科植物鼠尾草的DXS基因进化关系较近，均属于DXS1亚家族。密码子偏性分析表明，该基因偏好使用以A/T结尾的密码子，具有28个偏性密码子，烟草为该基因最适合的外源表达宿主。结论 成功克隆荆芥StDXS基因并进行生物信息学分析，为从分子水平调控荆芥的生长发育和改善药材产量和品质提供理论基础。

Objective To clone 1-deoxy-D-xylulose 5-phosphate synthase (StDXS) gene from Schizonepeta tenuifolia and perform the bioinformatics analysis. Methods The full-length cDNA sequence of StDXS gene was cloned by using RT-PCR based on transcriptome sequencing data of S. tenuifolia generated in the previous study and further analyzed by bioinformatic methods. Results The cloned StDXS gene was 2 177 bp, containing a 2 157 bp open reading frame (ORF) which encoded 718 amino acids. The theoretical molecular weight was 77 240 and its isoelectric point was 6.32. StDXS protein might be located in the chloroplast, and it had no signal peptide and membrane spaning domain, it was non-secretory protein. Phylogenetic analysis indicated that sequence of amino acids was closely related to the evolution of Salvia officinalis of the same family, and they both belonged to DXS1 family. Codon bias analysis showed that StDXS gene prefered to use A/T ending codon, with 28 skewed codons. Nicotiana tabacum was the most suitable host for exogenous expression of StDXS gene. Conclusion The StDXS gene was cloned from S. tenuifolia successfully and its bioinformatics analysis was performed, which provided a theoretical basis for regulating the growth and development of S. tenuifolia and improving the yield and quality of S. tenuifolia.

R286.12

国家自然科学基金面上项目（81973435）；国家自然科学基金面上项目（81473313）；国家自然科学基金青年科学基金项目（81903756）