College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, China.
College of Life Sciences, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China.
Sci Rep. 2017 Jul 11;7(1):5104. doi: 10.1038/s41598-017-04909-w.
Phenolic acids and tanshinones are two major bioactive components in Salvia miltiorrhiza Bunge. A novel endogenous R2R3-MYB transcription factor, SmMYB36, was identified in this research. This transcript factor can simultaneously influence the content of two types of components in SmMYB36 overexpression hairy roots. SmMYB36 was mainly localized in the nucleus of onion epidermis and it has transactivation activity. The overexpression of SmMYB36 promoted tanshinone accumulation but inhibited phenolic acid and flavonoid biosynthesis in Salvia miltiorrhiza hairy roots. The altered metabolite content was due to changed metabolic flow which was regulated by transcript expression of metabolic pathway genes. The gene transcription levels of the phenylpropanoid general pathway, tyrosine derived pathway, methylerythritol phosphate pathway and downstream tanshinone biosynthetic pathway changed significantly due to the overexpression of SmMYB36. The wide distribution of MYB binding elements (MBS, MRE, MBSI and MBSII) and electrophoretic mobility shift assay results indicated that SmMYB36 may be an effective tool to regulate metabolic flux shifts.
丹酚酸和丹参酮是丹参中的两种主要生物活性成分。本研究鉴定了一种新型内源性 R2R3-MYB 转录因子 SmMYB36。该转录因子可以同时影响 SmMYB36 过表达毛状根中两种成分的含量。SmMYB36 主要定位于洋葱表皮细胞的细胞核中，具有转录激活活性。SmMYB36 的过表达促进丹参酮的积累，但抑制丹参毛状根中酚酸和类黄酮的生物合成。代谢物含量的改变是由于代谢流的改变，这是由代谢途径基因的转录表达调节的。由于 SmMYB36 的过表达，苯丙烷类通用途径、酪氨酸衍生途径、甲基赤藓醇磷酸途径和下游丹参酮生物合成途径的基因转录水平发生了显著变化。广泛分布的 MYB 结合元件（MBS、MRE、MBSI 和 MBSII）和电泳迁移率变动分析结果表明，SmMYB36 可能是调节代谢通量转移的有效工具。
