目的 克隆粗茎秦艽Gentiana crassicaulis的裂环马钱苷合酶（secologanin synthase，SLS）基因GcSLS，分析其理化性质、系统进化关系、组织表达特性，为进一步研究植物萜类化合物生物合成通路中的关键酶及其作用机制提供基础资料。方法 依据粗茎秦艽转录组数据，注释、筛选并克隆GcSLS基因；使用生物信息学工具分析其编码的氨基酸序列、结构域等，预测其编码蛋白的理化性质；使用MEGA11软件分析进化关系，并利用荧光定量PCR检测GcSLS基因在不同组织中的相对表达水平。结果 从粗茎秦艽中成功克隆获得GcSLS基因，其开放阅读框（open reading frame，ORF）序列全长共计1 566 bp，编码521个氨基酸，蛋白质相对分子质量为59 590，为碱性亲水稳定蛋白，具有细胞色素P450的保守域并含有1处跨膜结构。荧光定量PCR结果显示，GcSLS在粗茎秦艽根和花中的表达量显著高于在叶和茎中的表达量；且该基因受茉莉酸甲酯（methyl jasmonate，MeJA）诱导后表达水平显著上调。结论 获得粗茎秦艽GcSLS序列基础信息，分析序列特征及表达模式，可为深入探究GcSLS在萜类化合物合成通路中的功能提供科学资料。

Objective To clone secologanin synthase (SLS) gene from Gentiana crassicaulis (GcSLS) and carry out physical and chemical properties, system evolutionary relationships, organization expression characteristic analysis. Methods Based on the annotation results of transcriptome data, we cloned the GcSLS from G. crassicaulis, analyzed its amino acid coding sequences and predicted the protein domains, physical and chemical properties and structure features. MEGA 11 software was used for evolutionary analysis. Quantitative PCR was employed to detect the expression levels of GcSLS in different tissues. Results We successfully cloned the GcSLS, and the ORF of GcSLS was 1 566 bp in length, encoding a 521 aa protein with a molecular weight of 59 590. It was a hydrophilic protein with a transmembrane domain, P450 conserved domains and no signal peptides. The results of quantitative PCR showed that the expression of GcSLS in roots and flowers was significantly higher than that in leaves and stems, and the expression of GcSLS was significantly induced by methyl jasmonate (MeJA). Conclusion The basic information, sequence characteristics and expression pattern of GcSLS may provide scientific data for further investigation of the function of GcSLS in the synthesis pathway of terpenoids.

R286.12

国家自然科学基金面上项目（82073959）；西藏自治区藏医药管理局科研课题（JJKT2020017）