目的 克隆大花胡麻草环烯醚萜合酶基因（CgIS），并进行表达分析。方法 以大花胡麻草根、茎、叶转录组中唯一的CgIS基因序列为基础，采用RT-PCR技术从大花胡麻草幼叶克隆CgIS基因，并进行组织特异性表达分析。结果 大花胡麻草CgIS基因（GenBank登录号MH794270）全长1 185 bp，编码394个氨基酸；CgIS蛋白相对相对分子质量44 670，理论pI为6.17；该蛋白属于孕酮5β-还原酶（P5β-R）家族成员，可能定位于细胞质；该蛋白无信号肽，为亲水稳定蛋白，主要由α-螺旋（40.61%）和无规则卷曲（46.70%）构成；该蛋白具有SDR（短链脱氢酶/还原酶）和P5βR蛋白保守结构域；CgIS蛋白与芝麻SiIS蛋白亲缘关系最近；CgIS基因主要在叶中表达。结论 克隆了CgIS基因，并对其进行表达分析，为进一步研究该基因的功能和环烯醚萜类的生物合成途径奠定基础。

Objective To clone the CgIS gene encoding iridoid synthase from Centranthera grandiflora and conduct its expression analysis. Methods Based on the sole sequence of CgIS gene in root, stem and leaf transcriptome of C. grandiflora, a CgIS gene was cloned from young leaves of C. grandiflora by RT-PCR technique, and its tissue-specific expressions were also performed. Results The CgIS gene (GenBank accession number:MH794270) had a length of 1 185 bp coding for 394 amino acids, and the relative molecular weight of CgIS protein was 44 670 with its theoretical pI of 6.17. CgIS protein belonged to the member of P5βR (progesterone 5β-reductase) family, and might localize in cytoplasm. CgIS protein was a hydrophilic stable protein without signal peptide, and composed of mainly α-helix (40.61%) and coil (46.70%). The SDR (short-chain dehydrogenase/reductase) and P5βR conserved domains were existed in CgIS protein. CgIS protein was close to SiIS protein of Sesamum indicum. CgIS gene was primarily expressed in leaves. Conclusion The CgIS gene is cloned, and its expressions are also analyzed, which will pave a way for further studies on function of CgIS gene and biosynthetic pathway of iridoids.

R282.12

云南省高校基础研究联合专项（2017FH001-024）；国家级大学生创新性项目（201811390007）；云南省科技计划项目（2016FD113）