Terpene trilactones (TTLs) have important medicinal value, but their low content in Ginkgo biloba leaves makes their exploitation extremely costly, thereby limiting the development of TTL related industries. It was found that exogenous methyl jasmonate (MeJA) treatment increased the accumulation of TTLs, but the molecular mechanism is still unclear. Here, we identified two bHLH transcription factors in G. biloba, with the protein subcellular localizations in the nucleus. GbMYC2s expression was strongly induced by MeJA treatment, and the interactions between GbJAZs and GbMYC2s were demonstrated by yeast two-hybrid and bimolecular fluorescence complementation experiments. Overexpression of GbMYC2_4 and GbMYC2_5 enhanced Arabidopsis root sensitivity and significantly increased TTL content. In addition, GbGGPPS was found to be a common target of GbMYC2_4 and GbMYC2_5 by yeast one-hybrid, electrophoretic mobility shift assay, dual-luciferase reporter assay, and DAP-seq, and they achieved regulation of GbGGPPS by binding to G-box. Further findings revealed that GbMYC2_4 and GbMYC2_5 bind G-box not universally but selectively. Our study revealed that jasmonic acid signaling mediates TTL biosynthesis through the GbJAZ-GbMYC2-GbGGPPS module, which enriches the terpenoid biosynthesis regulatory networks and provides a research basis and target genes for enhancing TTL content through genetic engineering.

中文翻译：

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转录因子MYC2通过激活银杏中的GbGGPPS表达正向调节萜三内酯生物合成


萜烯三内酯(TTL)具有重要的药用价值，但银杏叶中的含量较低，导致其开发成本极高，从而限制了TTL相关产业的发展。研究发现，外源茉莉酸甲酯（MeJA）处理增加了TTL的积累，但分子机制仍不清楚。在这里，我们在银杏中鉴定了两个 bHLH 转录因子，其蛋白质亚细胞定位于细胞核中。 MeJA处理强烈诱导GbMYC2s表达，酵母双杂交和双分子荧光互补实验证明了GbJAZs和GbMYC2s之间的相互作用。 GbMYC2_4和GbMYC2_5的过表达增强了拟南芥根系敏感性并显着增加了TTL含量。此外，通过酵母单杂交、电泳迁移率变动分析、双荧光素酶报告基因分析和DAP-seq发现GbGGPPS是GbMYC2_4和GbMYC2_5的共同靶标，并通过与G-box结合实现对GbGGPPS的调控。进一步的研究结果表明，GbMYC2_4 和 GbMYC2_5 不是普遍地而是选择性地结合 G-box。我们的研究揭示了茉莉酸信号通过GbJAZ-GbMYC2-GbGGPPS模块介导TTL生物合成，丰富了萜类生物合成调控网络，为通过基因工程提高TTL含量提供了研究基础和靶基因。