Taxus, commonly known as yew, is a well-known gymnosperm with great ornamental and medicinal value. In this study, by assembling a chromosome-level genome of the Himalayan yew (Taxus wallichiana) with 10.9 Gb in 12 chromosomes, we revealed that tandem duplication acts as the driving force of gene family evolution in the yew genome, resulting in the main genes for paclitaxel biosynthesis, i.e. those encoding the taxadiene synthase, P450s, and transferases, being clustered on the same chromosome. The tandem duplication may also provide genetic resources for the nature to sculpt the core structure of taxoids at different positions and subsequently establish the complex pathway of paclitaxel by neofunctionalization. Furthermore, we confirmed that there are two genes in the cluster encoding isoenzymes of a known enzyme in the paclitaxel biosynthetic pathway. The reference genome of the Himalayan yew will serve as a platform for decoding the complete biosynthetic pathway of paclitaxel and understanding the chemodiversity of taxoids in gymnosperms.

红豆杉，俗称红豆杉，是著名的裸子植物，具有很高的观赏和药用价值。在这项研究中，通过组装喜马拉雅红豆杉 ( Taxus wallichiana ) 的染色体水平基因组) 在 12 条染色体中有 10.9 Gb 的情况下，我们揭示了串联重复是红豆杉基因组中基因家族进化的驱动力，导致紫杉醇生物合成的主要基因，即编码紫杉二烯合酶、P450s 和转移酶的基因聚集在一起在同一条染色体上。串联复制也可能为自然界提供遗传资源，在不同位置雕刻紫杉醇的核心结构，进而通过新功能化建立紫杉醇的复杂通路。此外，我们证实在紫杉醇生物合成途径中编码已知酶的同工酶的簇中有两个基因。