受蓝光诱导的调控青蒿素合成的bZIP转录因子的挖掘以及功能验证

Artemisinin is the most effective drug in the treatment of acute malaria. At present, extraction from Artemisia annua is the main way to obtain artemisinin, but its content is generally low. Therefore, how to improve the content of artemisinin in Artemisia annua by biotechnology is a problem that people have been very concerned about. Overexpression of transcription factors is a more effective way to regulate plant secondary metabolites. We found that blue light can promote the synthesis of artemisinin in vivo. Then we analyzed the expression of all bZIP transcription factors in Artemisia annua and screened out the bZIP transcription factors which were induced by blue light and highly expressed in glandular trichome where artemisinin was synthesized. Next, the phylogenetic analysis of these genes was carried out, finally, six candidate genes mediating blue light signal to regulate artemisinin synthesis were identified. Furthermore, we analyzed the promoters of ADS and CYP71AV1, the key structural genes for artemisinin biosynthesis, and found that they contained transient elements bZIP transcription factors can binding to. We will further study the transcriptional regulation mechanism of candidate genes on artemisinin synthesis to reveal how blue light regulates artemisinin synthesis. To provide theoretical and technical support for further improvement of artemisinin biosynthesis and metabolism, and to provide reference for the improvement of Artemisia annua breeds.

青蒿素是治疗急性疟疾最有效的药物。目前从黄花蒿中提取是获取青蒿素的主要方式，但其含量一般都很低。因此，如何通过生物技术手段提高黄花蒿中青蒿素的含量是人们一直十分关心的问题。过表达转录因子是更有效调控植物次生代谢产物的方法。我们发现蓝光能够促进青蒿素在体内的合成，然后我们对黄花蒿中所有的bZIP转录因子的表达进行了分析，筛选到了受蓝光诱导并且在合成青蒿素的部位腺毛中高表达的bZIP转录因子。接下来对它们进行了系统进化分析，最终确定了介导蓝光信号调控青蒿素合成的6个候选基因。之后我们还对青蒿素合成关键结构基因ADS和CYP71AV1的启动子进行了分析，发现其中含有bZIP转录因子结合的瞬时作用元件。后续我们将对候选基因在青蒿素合成的转录调控机制上进行深入研究，以揭示蓝光是如何调控青蒿素积累的。为进一步改良青蒿素生物合成和代谢提供理论和技术支撑，为黄花蒿品种改良提供参考。

疟疾是一种由疟原虫感染引起的严重威胁人类健康和生命安全的重大传染病。以青蒿素为基础的联合用药(artemisinin-based combination therapies，ACTs)是治疗疟疾特别是恶性疟现有的首选、最佳方法。目前从植物黄花蒿中提取是获得青蒿素的主要途径，但是黄花蒿中青蒿素含量一般都很低。因此，如何提高黄花蒿中青蒿素的含量具有重大意义。我们在前期的研究中发现使用蓝光能够显著促进黄花蒿中青蒿素的合成。由于植物中次生代谢产物的合成通常受转录因子调控，为了揭示蓝光促进青蒿素合成的转录调控机制， 我们分析了黄花蒿中所有的bZIP转录因子。通过筛选和鉴定得到78个bZIP转录因子，对它们进行了进化和进化压力分析，之后分析了它们的蛋白保守结构域。进一步分析了它们在不同波段光下的表达情况，筛选出两个bZIP转录因子。通过烟草LUC报告基因系统发现，这两个转录因子能够显著地促进ADS的基因表达。我们进一步还发现激素赤霉素GA能够协同UV来促进青蒿素的合成。同时我们分析了黄花蒿中全长转录本，发现不同的光能够调控转录本的可变剪切从而影响青蒿素的合成。这些分子机制的解析为科学阐明光促进青蒿素合成的转录调控机制奠定理论基础，为黄花蒿遗传改良和提高青蒿素产量奠定基础。