Dipterocarpaceae are typical tropical plants (dipterocarp forests) that are famous for their high economic value because of their production of fragrant oleoresins, top-quality timber and usage in traditional Chinese medicine. Currently, the lack of Dipterocarpaceae genomes has been a limiting factor to decipher the fragrant oleoresin biosynthesis and gain evolutionary insights into high-quality wood formation in Dipterocarpaceae. We generated chromosome-level genome assemblies for two representative Dipterocarpaceae species viz. Dipterocarpus turbinatus Gaertn. f. and Hopea hainanensis Merr. et Chun. Our whole-genome duplication (WGD) analysis revealed that Dipterocarpaceae underwent a shared WGD event, which showed significant impacts on increased copy numbers of genes related to the biosynthesis of terpene, BAHD acyltransferases, fatty acid and benzenoid/phenylpropanoid, which probably confer to the formation of their characteristic fragrant oleoresin. Additionally, compared with common soft wood plants, the expansion of gene families was also found to be associated with wood formation, such as in CESA (cellulose synthase), CSLE (cellulose synthase-like protein E), laccase and peroxidase in Dipterocarpaceae genomes, which might also contribute to the formation of harder, stronger and high-density timbers. Finally, an integrative analysis on a combination of genomic, transcriptomic and metabolic data from different tissues provided further insights into the molecular basis of fragrant oleoresins biosynthesis and high-quality wood formation of Dipterocarpaceae. Our study contributes the first two representative genomes for Dipterocarpaceae, which are valuable genetic resources for further researches on the fragrant oleoresins and superior-quality timber, genome-assisted breeding and improvement, and conservation biology of this family.

中文翻译：

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Dipterocarpus turbinatus 和 Hopea hainanensis (Dipterocarpaceae) 的染色体尺度基因组提供了对芳香油树脂生物合成和硬木形成的见解

龙脑香科植物是典型的热带植物（龙脑香林），因其出产香油树脂、优质木材和中药材而闻名于世，具有很高的经济价值。目前，龙脑香科基因组的缺乏一直是破译芳香油树脂生物合成和获得龙脑香科高质量木材形成的进化见解的限制因素。我们为两个有代表性的龙脑香科物种（即）生成了染色体水平的基因组组装。Dipterocarpus turbinatus Gaertn. F。和海南希望梅尔。等春。我们的全基因组重复 (WGD) 分析表明，龙脑香科经历了一个共享的 WGD 事件，这表明与萜烯、 BAHD酰基转移酶、脂肪酸和苯类/苯丙烷的生物合成相关的基因拷贝数增加有显着影响，这可能赋予形成其特有的芳香油树脂。此外，与常见的软木植物相比，还发现基因家族的扩展与木材的形成有关，例如在CESA（纤维素合酶）、CSLE（纤维素合酶样蛋白 E）、龙脑香科基因组中的漆酶和过氧化物酶，这也可能有助于形成更硬、更强和高密度的木材。最后，对来自不同组织的基因组、转录组和代谢数据的综合分析，为龙脑香科芳香油树脂生物合成和优质木材形成的分子基础提供了进一步的见解。我们的研究贡献了龙脑香科的前两个代表性基因组，为进一步研究该科的芳香油树脂和优质木材、基因组辅助育种和改良以及保护生物学提供了宝贵的遗传资源。