D-Borneol is a precious monoterpenoid widely used in the pharmaceutical and cosmetic industries. Cinnamomum burmannii (Nees et T.Nees) Blume (C. burmannii) is one of the key resources for D-Borneol. However, only one chemotype of C. burmannii contain high content of D-Borneol in its leaves and stems. Limited by little information from C. burmannii, the D-Borneol biosynthesis mechanisms, as well as the mechanisms underlying the D-Borneol production differences among chemotypes remains elusive. To fill these gaps, we generated a completed genome of a high D-Borneol content chemotype of C. burmannii. Phylogenetic analysis suggests that C. burmannii is sister to a clade containing C. camphora and C. kanehirae while the variations of chromosome structure and LTR-RTs are important factors for differentiation in Cinnamomum. Further comparison of genome sequence demonstrated few genomic sequence differences between two chemotypes of C. burmannii. However, the pathway and transcriptomic profiling analysis revealed the expression differences of the genes in MEP pathway, a main pathway responsible for D-Borneol synthesis, which may be the critical determinant for the D-Borneol production differences between the two chemotypes. Our results also implied epigenetic modulation may participate in this process. Finally, a genome database (CAMD) of Cinnamomum species was constructed for better resources exploration. The present study provided the first high-quality genome and comprehensive genomic resources of C. burmannii. which not only provided new insights into the evolution of Cinnamomum species, but also shed light on the mechanisms of D-Borneol biosynthesis and the molecular signatures characterized high and low D-Borneol chemotypes of C. burmannii.

D-冰片是一种珍贵的单萜类化合物，广泛用于医药和化妆品行业。Cinnamomum burmannii (Nees et T.Nees) Blume ( C. burmannii ) 是D-冰片的主要资源之一。然而，只有一种化学型的C. burmannii在其叶和茎中含有高含量的D-冰片。受限于来自C. burmannii的少量信息，D-冰片的生物合成机制以及化学型之间D-冰片产生差异的潜在机制仍然难以捉摸。为了填补这些空白，我们生成了一个完整的高D基因组-C . burmannii的冰片含量化学型。系统发育分析表明C. burmannii是含有C. camphora和C. kanehirae的进化枝的姐妹，而染色体结构和 LTR-RTs 的变化是Cinnamomum分化的重要因素。基因组序列的进一步比较表明， C. burmannii的两种化学型之间几乎没有基因组序列差异。然而，通路和转录组学分析揭示了 MEP 通路中基因的表达差异，MEP 通路是负责D -冰片合成的主要途径，这可能是 D-冰片的关键决定因素。-两种化学型之间的冰片产量差异。我们的结果还暗示表观遗传调控可能参与了这一过程。最后，为了更好地进行资源勘探，构建了肉桂物种的基因组数据库（CAMD） 。本研究提供了第一个高质量的布氏梭菌基因组和全面的基因组资源。这不仅为Cinnamomum物种的进化提供了新的见解，而且还阐明了D-冰片的生物合成机制以及C. burmannii高和低D-冰片化学型的分子特征。