As one of the most economically significant Oleaceae family members, Jasminum sambac is renowned for its distinct sweet, heady fragrance. Using Illumina reads, Nanopore long reads, and HiC-sequencing, we efficiently assembled and annotated the J. sambac genome. The high-quality genome assembly consisted of a total of 507 Mb sequence (contig N50 = 17.6 Mb) with 13 pseudomolecules. A total of 21,143 protein-coding genes and 303 Mb repeat sequences were predicted. An ancient whole-genome triplication event at the base of Oleaceae (~66 million years ago [Ma], Late Cretaceous) was identified and this may have contributed to the diversification of the Oleaceae ancestor and its divergence from the Lamiales. Stress-related (e.g., WRKY) and flowering-related (e.g., MADS-box) genes were located in the triplicated regions, suggesting that the polyploidy event might have contributed adaptive potential. Genes related to terpenoid biosynthesis, for example, FTA and TPS, were observed to be duplicated to a great extent in the J. sambac genome, perhaps explaining the strong fragrance of the flowers. Copy number changes in distinct phylogenetic clades of the MADS-box family were observed in J. sambac genome, for example, AGL6- and Mα- were lost and SOC- expanded, features that might underlie the long flowering period of J. sambac. The structural genes implicated in anthocyanin biosynthesis were depleted and this may explain the absence of vivid colours in jasmine. Collectively, assembling the J. sambac genome provides new insights into the genome evolution of the Oleaceae family and provides mechanistic insights into floral properties.

中文翻译：

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Jasminum sambac 的高质量基因组组装提供了对花性状形成和木犀科基因组进化的洞察

作为经济上最重要的木犀科成员之一，沙巴茉莉以其独特的甜美、令人陶醉的香味而闻名。使用 Illumina 读取、Nanopore 长读取和 HiC 测序，我们有效地组装和注释了J. sambac基因组。高质量的基因组组装由总共 507 Mb 序列（contig N50 = 17.6 Mb）和 13 个假分子组成。共预测了 21,143 个蛋白质编码基因和 303 Mb 重复序列。在木犀科底部（约 6600 万年前 [Ma]，晚白垩纪）发现了一个古老的全基因组三倍体事件，这可能有助于木犀科祖先的多样化及其与唇形目的分化。压力相关（例如，WRKY）和开花相关（例如，MADS-box）基因位于三倍体区域，表明多倍体事件可能贡献了适应性潜力。与萜类生物合成相关的基因，例如FTA和TPS ，在J. sambac基因组中被观察到在很大程度上重复，这可能解释了花的强烈香味。在J. sambac基因组中观察到 MADS-box 家族的不同系统发育进化枝的拷贝数变化，例如，AGL6 - 和 Mα- 丢失并且SOC - 扩展，这些特征可能是J. sambac长开花期的基础. 与花青素生物合成有关的结构基因被耗尽，这可以解释茉莉花中没有鲜艳的颜色。总的来说，组装J. sambac基因组为木犀科的基因组进化提供了新的见解，并提供了对花卉特性的机制见解。