丹参酮是丹参的主要药效成分，合成途径受多种因子的调控。碱性螺旋-环-螺旋(basic helix-loop-helix, bHLH)转录因子家族对植物的生长代谢、活性物质合成、胁迫响应等有重要影响。为探究bHLH在丹参酮合成中的作用，本研究通过基因克隆获得丹参bHLH家族基因SmbHLH59的全长编码序列，并对其进行生物信息学和表达特征分析。结果表明，SmbHLH59结构保守，含有3个外显子和2个内含子。SmbHLH59蛋白由226个氨基酸组成，呈弱酸性，疏水性较强，属脂溶性蛋白，稳定性差，无规则卷曲数量多，复杂性较高，亚细胞定位于细胞核，与一串红的bHLH126亲缘关系最近。SmbHLH59的启动子区域富含响应植物激素的顺式作用元件。表达分析显示SmbHLH59在丹参红根韧皮部中表达量最高，受茉莉酸甲酯诱导上调表达，推测该基因与红根中丹参酮的合成有关且其作用受到茉莉酸甲酯的调控。本研究结果可为深入研究SmbHLH59基因的功能奠定重要基础。

Tanshinones are the primary bioactive compounds in Salvia miltiorrhiza, and their biosynthetic pathways are regulated by various factors. The basic helix-loop-helix(bHLH) transcription factor family plays crucial roles in plant growth metabolism, secondary metabolite synthesis, and stress responses. To explore the role of bHLH in tanshinone biosynthesis, the full-length coding sequence(CDS) of SmbHLH59 was cloned from S. miltiorrhiza, followed by comprehensive bioinformatics and expression profile analyses. The results showed that SmbHLH59 was conserved in structure, containing three exons and two introns. The SmbHLH59 protein was composed of 226 amino acids with weak acidity and highly hydrophobicity, and was a lipophilic protein. It was characterized by low stability, a high proportion of random coils, and high complexity. Subcellular localization predicted that SmbHLH59 was located in the nucleus. It had the closest relationship with bHLH126 from Citrus splendens. The promoter region of SmbHLH59 was enriched with cis-acting elements response to phytohormones. Expression analysis revealed that SmbHLH59 reached the highest expression level in phloem of the red roots and was significantly up-regulated when induced by methyl jasmonate(MeJA), which suggested that SmbHLH59 was involved in tanshinone biosynthesis in the red roots and was regulated by MeJA. This study could provide a vital foundation for further functional characterization of the SmbHLH59 gene.