目的 对川射干（Iris tectorum Maxim.）中可能参与黄酮类化合物生物合成的糖基转移酶基因ItUGT797展开初步研究，解析ItUGT797编码蛋白的各项生物信息指标并优化其原核表达体系。方法 提取鸢尾各组织部位的RNA并进行反转录获得cDNA文库，根据鸢尾转录组中ItUGT797基因序列设计基因特异性引物，通过同源克隆的方法构建pET-32a （+）-ItUGT797原核表达重组载体。使用各类生物信息学网站对测序后的ItUGT797序列进行理化性质、蛋白结构和进化关系等分析；实时荧光定量PCR（Quantitative Real-time PCR）验证基因在各部位的表达情况；蛋白体外表达情况则使用大肠杆菌体系检测。结果 ItUGT797开放阅读框长度为1455 bp，编码蛋白分子量大小分别为53.80 kDa。ItUGT797在各组织中表达情况为花>叶>根茎。系统发育进化树表明，ItUGT797可能是具有7-O-糖基化活性的糖基转移酶。原核表达结果显示在诱导剂IPTG为0.1mM时，ItUGT797能够表达出较多的可溶性蛋白。结论 本研究成功从鸢尾中克隆了ItUGT797基因，并分析了其编码蛋白的特征，检测了基因在根茎、叶和花中的表达量，同时通过原核表达体系筛选出最适合该基因可溶性蛋白表达的诱导剂浓度，为后续探索其参与鸢尾中黄酮类成分生物合成的功能奠定理论基础。

Objective To perform a preliminary study on the glycosyltransferase gene ItUGT797 that may be involved in the biosynthesis of tectoridin in Iris tectorum Maxim, so as to perform bioinformatics analysis and apply prokaryotic expression vector.Methods RNA from all parts of Iris tectorum was extracted and transformed to obtain cDNA library. Construction of pET-32a (+)-ItUGT797 prokaryotic expression recombinant vector was performed with designed specific primers based on transcriptome data of Iris tectorum. Diverse bioinformatics online tools were used to analyze various indicators and evolutionary relationship of the encoded protein; The expression level of ItUGT797 in various parts was detected by Quantitative Real-time PCR (QPCR); The Escherichia coli system was used to test protein expression.Results The open reading frame of ItUGT797 gene reached to 1455 bp in length and its molecular weight was 53.80 kDa respectively. The expression pattern of ItUGT797 in various tissues was showed as flower>leaf>rhizome. It could be concluded from phylogenetic tree that ItUGT797 may be a glycosyltransferase with 7-O-glycosylation activity. Prokaryotic expression results showed that ItUGT797 can express more soluble protein when induced by 0.1mM IPTG.Conclusion In this study, the ItUGT797 gene is successfully cloned from Iris tectorum, and the characteristics of its encoded protein is detected. The gene expression condition in rhizomes, leaves and flowers are probed. At the same time, the most suitable inducer concentration for the soluble protein expression of the gene is selected through the prokaryotic expression system. The above results establish a research foundation for the succeeding exploration of its activity in the biosynthesis of flavonoids in Iris tectorum.

国家自然科学基金委员会-贵州省人民政府联合基金项目（U1812403-1）：特色药用植物资源适应性及保护研究，负责人：陈士林；广东省基础与应用基础研究基金委员会广东省基础与应用基础研究基金项目（2019A1515110594）：茉莉酸介导的SmERF128调控二萜合成分子机制研究，负责人：季爱加；广东省教育厅广东省级大学生创新训练项目（S202110572055）：南药穿心莲药效成分合成调控相关bZIP基因挖掘及功能鉴定，负责人：陶无恙。