Agarwood, generated from the Aquilaria sinensis, has high economic and medicinal value. Although its genome has been sequenced, the ploidy of A. sinensis paleopolyploid remains unclear. Moreover, the expression changes of genes associated with agarwood formation were not analyzed either. In the present work, we reanalyzed the genome of A. sinensis and found that it experienced a recent tetraploidization event ~ 63–71 million years ago (Mya). The results also demonstrated that the A. sinensis genome had suffered extensive gene deletion or relocation after the tetraploidization event, and exhibited accelerated evolutionary rates. At the same time, an alignment of homologous genes related to different events of polyploidization and speciation were generated as well, which provides an important comparative genomics resource for Thymelaeaceae and related families. Interestingly, the expression changes of genes related to sesquiterpene synthesis in wounded stems of A. sinensis were also observed. Further analysis demonstrated that polyploidization promotes the functional differentiation of the key genes in the sesquiterpene synthesis pathway. By reanalyzing its genome, we found that the tetraploidization event shaped the A. sinensis genome and contributed to the ability of sesquiterpenes synthesis. We hope that these results will facilitate our understanding of the evolution of A. sinensis and the function of genes involved in agarwood formation.

中文翻译：

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四倍体化事件塑造了沉香基因组并促进了倍半萜的合成能力


沉香是由沉香（Aquilaria sinensis）产生的，具有很高的经济和药用价值。尽管其基因组已被测序，但其古多倍体的倍性仍不清楚。此外，也没有分析与沉香形成相关的基因的表达变化。在目前的工作中，我们重新分析了中华猕猴桃的基因组，发现它在大约 63-7100 万年前经历了最近的四倍体化事件 (Mya)。结果还表明，中华猕猴桃基因组在四倍体化事件后发生了广泛的基因缺失或重定位，并表现出加速的进化速度。同时，还生成了与不同多倍化和物种形成事件相关的同源基因比对，这为瑞香科及相关科提供了重要的比较基因组学资源。有趣的是，我们还观察到了中华木受伤茎中倍半萜合成相关基因的表达变化。进一步分析表明，多倍化促进了倍半萜合成途径关键基因的功能分化。通过重新分析其基因组，我们发现四倍体化事件塑造了中华猕猴桃的基因组，并有助于其合成倍半萜的能力。我们希望这些结果将有助于我们了解沉香的进化以及沉香形成相关基因的功能。