College of Life Science, Northwest A&F University, Yangling, 712100, China.
College of Life Science, Yan'an University, Yan'an, China.
Planta. 2018 Jul;248(1):243-255. doi: 10.1007/s00425-018-2884-z. Epub 2018 Apr 27.
The SmERF6, which recognizes the GCC-box of SmCPS1 and SmKSL1 promoter in nucleus, regulates the tanshinone biosynthesis in Salvia miltiorrhiza hairy roots. Tanshinone, an important medicinal ingredient in Salvia miltiorrhiza, is best known for its use in medicine. However, the transcription factor regulation of tanshinone biosynthesis is unclear. Here, we isolated and identified a transcription factor in the ERF family of S. miltiorrhiza, SmERF6, which was screened from an S. miltiorrhiza cDNA library by the promoters of two key tanshinone synthesis genes (SmKSL1 and SmCPS1); this factor regulated tanshinone biosynthesis. The gene was highly expressed in the root and responded to ethylene treatment. SmERF6 modulated tanshinone biosynthesis by directly binding to an ethylene-responsive element (GCC-box) of the SmKSL1 and SmCPS1 promoters and activating their transcription. Overexpression of SmERF6 in the hairy roots increased their tanshinone accumulation, and SmERF6 silencing by RNAi led to a lower tanshinone content. Furthermore, tanshinone accumulation maintained homeostasis with the total phenolic acid and flavonoid contents in S. miltiorrhiza. These findings elucidated how SmERF6 directly co-regulates the transcription of SmCPS1 and SmKSL1 and modulates tanshinone synthesis to accelerate the metabolic flux of tanshinone accumulation in S. miltiorrhiza.
SmERF6，可识别 SmCPS1 和 SmKSL1 启动子中的 GCC 框，调节丹参毛状根中的丹参酮生物合成。丹参酮是丹参中的一种重要药用成分，以其在医学中的应用而闻名。然而，丹参酮生物合成的转录因子调控尚不清楚。在这里，我们从丹参 cDNA 文库中通过两个关键丹参酮合成基因（SmKSL1 和 SmCPS1）的启动子筛选出丹参 ERF 家族的转录因子 SmERF6，该因子调节丹参酮生物合成。该基因在根中高度表达，并对乙烯处理有反应。SmERF6 通过直接结合 SmKSL1 和 SmCPS1 启动子的乙烯反应元件（GCC 框）并激活它们的转录来调节丹参酮生物合成。在毛状根中过表达 SmERF6 会增加其丹参酮积累，而 SmERF6 通过 RNAi 沉默会导致丹参酮含量降低。此外，丹参酮积累与丹参中的总酚酸和类黄酮含量保持着内稳态。这些发现阐明了 SmERF6 如何直接共同调节 SmCPS1 和 SmKSL1 的转录，并调节丹参酮合成，以加速丹参酮在丹参中的积累代谢通量。
