檀香心材精油的主要成分是萜类化合物,其中约80%是α-檀香醇和β-檀香醇。在檀香心材的主要次生代谢产物的合成中,关键基因,檀香烯合酶(SaSSY),可以催化生产α-檀香烯和β-檀香烯(E,E)-FPP。此外,檀香烯被细胞色素单加氧酶SaCYP736A167催化形成檀香精油,然后产生一种香味。然而,关键基因檀香烯合酶的上游调控机制尚不清楚。在这项研究中,筛选了SaSSY(Sal3G10690)启动子转录因子和SaSSY顺式元件。结果表明,檀香cDNA文库的滴度为1.75×107CFU/mL,通过PCR鉴定的80%的插入片段长度超过750bp,文库的阳性率大于90%。SaSSY基因的启动子区显示具有潜在调节因子结合的结构基础。经过测序和生物信息学分析,我们成功获得了51个阳性克隆,并鉴定了4个潜在的SaSSY转录调节因子。Sal6G03620被注释为转录因子MYB36样,并且注解Sal8G07920为檀香中的小热激卵白HSP20。Sal1G00910被注解为一种假想的檀香卵白。Sal4G10880被注释为檀香中的同源异型盒-亮氨酸拉链蛋白(ATHB-15)。在这项研究中,使用酵母单杂交技术成功构建了檀香cDNA文库,筛选可能与SaSSY基因启动子相互作用的转录因子。本研究为探讨檀香心材形成的分子调控机制奠定了基础。
The main components of sandalwood heartwood essential oil are terpenoids, approximately 80% of which are α-santalol and β-santalol. In the synthesis of the main secondary metabolites of sandalwood heartwood, the key gene, santalene synthase (SaSSY), can produce α-santalene and β-santalene by catalyzed (E, E)-FPP. Furthermore, santalene is catalyzed by the cytochrome monooxygenase SaCYP736A167 to form sandalwood essential oil, which then produces a fragrance. However, the upstream regulatory mechanism of the key gene santalene synthase remains unclear. In this study, SaSSY (Sal3G10690) promoter transcription factors and SaSSY cis-elements were screened. The results showed that the titer of the sandalwood cDNA library was 1.75 × 107 CFU/mL, 80% of the inserted fragments identified by PCR were over 750 bp in length, and the positivity rate of the library was greater than 90%. The promoter region of the SaSSY gene was shown to have the structural basis for potential regulatory factor binding. After sequencing and bioinformatics analysis, we successfully obtained 51 positive clones and identified four potential SaSSY transcriptional regulators. Sal6G03620 was annotated as the transcription factor MYB36-like, and Sal8G07920 was annotated as the small heat shock protein HSP20 in sandalwood. Sal1G00910 was annotated as a hypothetical protein of sandalwood. Sal4G10880 was annotated as a homeobox-leucine zipper protein (ATHB-15) in sandalwood. In this study, a cDNA library of sandalwood was successfully constructed using a yeast one-hybrid technique, and the transcription factors that might interact with SaSSY gene promoters were screened. This study provides a foundation for exploring the molecular regulatory mechanism involved in the formation of sandalwood heartwood.