Abstract Sanghuangporus baumii (Pilát) L.W. Zhou & Y.C. Dai, a popular medicinal fungus, has been used to treat several diseases by its triterpenoids bioactive ingredient for many years. However, the triterpenoids content of S. baumii is low and their biosynthesis mechanisms are not clearly understood. In order to reveal the regulation mechanism of triterpenoids biosynthesis in S. baumii, the cDNA encoding isopentenyl diphosphate isomerase (IDI) involved in triterpenoids biosynthesis was cloned and named as SbIDI (GenBank number MK955885). The open reading frame of the SbIDI gene cDNA comprised 792 bp and encoded a polypeptide of 263 amino acids with a predicted protein molecular weight of 29.80 kDa. The transcript level of the SbIDI gene and triterpenoids content of S. baumii were detected at different developmental stages. The results showed that the transcript level of the SbIDI gene and triterpenoids content had almost the same trend of change, increased first and then decreased dynamically. The highest transcript level of the SbIDI gene occurred earlier than the highest triterpenoids content, indicating that the SbIDI gene may play an important role in triterpenoids biosynthesis in S. baumii. Moreover, the SbIDI gene cDNA was successfully expressed in Escherichia coli BL21 (DE3), and the protein bands were consistent with the prediction.The results will lay a foundation for further study of the function of the SbIDI gene.

中文翻译：

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鲍鱼桑黄异戊烯基二磷酸异构酶基因的克隆、分子特性及差异表达分析

摘要 Sanghuangporus baumii (Pilát) LW Zhou & YC Dai 是一种流行的药用真菌，多年来以其三萜类生物活性成分被用于治疗多种疾病。然而，鲍鱼三萜类化合物含量低，其生物合成机制尚不清楚。为了揭示鲍鱼三萜生物合成的调控机制，克隆了参与三萜生物合成的异戊烯二磷酸异构酶（IDI）的cDNA，并命名为SbIDI（GenBank编号MK955885）。SbIDI 基因 cDNA 的开放阅读框包含 792 bp，编码 263 个氨基酸的多肽，预测蛋白质分子量为 29.80 kDa。在不同发育阶段检测了SbIDI基因的转录水平和鲍鱼三萜含量。结果表明，SbIDI基因转录水平与三萜含量变化趋势基本一致，呈先增加后减少的动态变化趋势。SbIDI 基因的最高转录水平出现早于最高三萜含量，表明 SbIDI 基因可能在 S. baumii 三萜生物合成中起重要作用。此外，SbIDI基因cDNA在大肠杆菌BL21(DE3)中成功表达，蛋白条带与预测一致。该结果将为进一步研究SbIDI基因的功能奠定基础。SbIDI 基因的最高转录水平出现早于最高三萜含量，表明 SbIDI 基因可能在 S. baumii 三萜生物合成中起重要作用。此外，SbIDI基因cDNA在大肠杆菌BL21(DE3)中成功表达，蛋白条带与预测一致。该结果将为进一步研究SbIDI基因的功能奠定基础。SbIDI 基因的最高转录水平出现早于最高三萜含量，表明 SbIDI 基因可能在 S. baumii 三萜生物合成中起重要作用。此外，SbIDI基因cDNA在大肠杆菌BL21(DE3)中成功表达，蛋白条带与预测一致。该结果将为进一步研究SbIDI基因的功能奠定基础。