Zhang Meng, Jin Xiaofei, Chen Ying, Wei Mi, Liao Weifang, Zhao Shengying, Fu Chunhua, Yu Longjiang
Department of Biotechnology, Institute of Resource Biology and Biotechnology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
Key Laboratory of Molecular Biophysics, Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China.
Front Plant Sci. 2018 Jun 21;9:863. doi: 10.3389/fpls.2018.00863. eCollection 2018.
The multitherapeutic taxol, which can be obtained from spp., is the most widely used anticancer drug. Taxol biosynthesis is significantly regulated by jasmonate acid (JA), one of the most important endogenous hormones in land plants. Nevertheless, the JA-inducing mechanism remains poorly understood. MYC2 is one of the key regulators of JA signal transfer and the biosynthesis of various secondary metabolites. Here, TcMYC2a was identified to contain a basic helix-loop-helix (bHLH)-leucine zipper domain, a bHLH-MYC_N domain, and a BIF/ACT-like domain. TcMYC2a was also found to bind with TcJAZ3 in yeast, which was a homolog of JASMONATE ZIM-domain JAZ proteins, indicating that TcMYC2a had a similar function to AtMYC2 of JA signal transduction. TcMYC2a was able to affect the expression of GUS reporter gene by binding with the T/G-box, G-box, and E-box, which were the key -elements of and promoter. overexpression also led to significantly increased expression of , , , , and genes. Additionally, TcERF15, which played the positive role to regulate gene, was up-regulated by TcMYC2a. All these results revealed that TcMYC2a can regulate taxol biosynthesis either directly or via ERF regulators depending on JA signaling transduction.
可从 spp. 中获取的多效性抗癌药物紫杉醇是使用最广泛的抗癌药物。紫杉醇的生物合成受到茉莉酸（JA）的显著调控，茉莉酸是陆地植物中最重要的内源激素之一。然而，茉莉酸诱导机制仍知之甚少。MYC2 是茉莉酸信号传递和各种次生代谢产物生物合成的关键调节因子之一。在此，鉴定出 TcMYC2a 包含一个碱性螺旋-环-螺旋（bHLH）-亮氨酸拉链结构域、一个 bHLH-MYC_N 结构域和一个 BIF/ACT 样结构域。还发现 TcMYC2a 在酵母中与 TcJAZ3 结合，TcJAZ3 是茉莉酸 ZIM 结构域 JAZ 蛋白的同源物，这表明 TcMYC2a 与茉莉酸信号转导的 AtMYC2 具有相似功能。TcMYC2a 能够通过与 T/G 盒、G 盒和 E 盒结合来影响 GUS 报告基因的表达，这些是 和 启动子的关键元件。 的过表达也导致 、 、 、 和 基因的表达显著增加。此外，对 基因起正向调控作用的 TcERF15 被 TcMYC2a 上调。所有这些结果表明，TcMYC２a 可根据茉莉酸信号转导直接或通过 ERF 调节因子调控紫杉醇的生物合成。
