檀香（Santalum album L.）为檀香科常绿乔木，从其心材中提取的檀香精油价值是黄金的三倍，素有“液体黄金”之称，其主要成分为檀香醇，约占80%以上。在自然生长条件下檀香需6-8年才开始形成心材，30-40年获经济收益，因此，开展促成檀香心材形成具有重要意义。但目前对檀香醇生物合成的调控机制认识仍不清楚。我们的前期研究表明：外源细胞分裂素能显著促成檀香心材形成；MYB，bHLH或WRKY类转录因子可能在檀香醇生物合成关键基因SaSSY、SaCYP736A167和SaCYP76F39V1的表达中具重要的调控作用。本项目拟应用生理生化、转录组学、分子生物学等技术研究：檀香醇生物合成的转录调控网络；细胞分裂素诱导檀香醇合成的作用机制；转录因子调控檀香醇生物合成的分子机制。研究结果为檀香的育种改良提供分子生物学基础，为实现人工促成檀香心材形成和提高经济效益具有重要应用价值。

Santalum album is an evergreen tree in Santalaceae. Sandalwood oil extracted from heartwood is very expensive and its value is three times to gold, in which major constituents are santalol ( > 80%), known as “Liquid Gold”. S. album starts to form heartwood about six to ten years after planting at normal growth condition and gain economic benefits after planting thirty to forty years. Therefore, it is of important sigificance to induct heartwood formation of S. album. To date, little is known about the regulation mechanism of santalol biosynthesis. .In our preliminary study, we found that exogenous cytokinin could remarkablely induce heartwood formation in S. album. Transcription factors, MYB, bHLH or WRKY may play important roles in regulating expression of SaSSY, SaCYP736A167 and SaCYP76F39V1 that are key genes involved in santalol biosynthesis. This project proposal that developed based on our preliminary results aims to study: (1) transcriptional regulatory networks of santalol biosynthesis, (2) the mechanisms of sandalol biosynthesis induced by cytokinin; (3) molecular regulation mechanism of MYB, bHLH or WRKY on expression of SaSSY, SaCYP736A167 and SaCYP76F39V1 based on plant physiology and biochemistry, molecular biology, combined with transcriptomic methods..The result of this project will help to understand molecular regualtion mechanism of santalol bisynthesis, but also has important significance in developing a practical method or technology to induce heartwood formation and enhance economic benefits in sandalwood industry.