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 通过激活银杏叶中 GbGGPPS 的表达正向调节萜烯三内酯的生物合成


萜烯三内酯 （TTLs） 具有重要的药用价值，但其在银杏叶中的低含量使其开发成本极高，从而限制了 TTL 相关产业的发展。研究发现，外源性茉莉酸甲酯 （MeJA） 处理增加了 TTLs 的积累，但分子机制仍不清楚。在这里，我们在 G. biloba 中鉴定了两个 bHLH 转录因子，蛋白质亚细胞定位在细胞核中。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的敏感性并显着增加了 TTL 含量。此外，通过酵母单杂交、电泳迁移率变化测定、双荧光素酶报告基因测定和 DAP-seq 发现 GbGGPPS 是 GbMYC2_4 和 GbMYC2_5 的共同靶标，它们通过与 G-box 结合实现对 GbGGPPS 的调节。进一步的发现显示，GbMYC2_4 和 GbMYC2_5 不是普遍结合 G-box，而是选择性结合。我们的研究表明，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，为通过基因工程增强 TTL 含量提供了研究基础和靶基因。