背景回顾：Patchouli (Pogostemon cablin (Blanco) Benth.), a member of the Lamiaceae family, is an important aromatic plant that has been widely used in medicine and perfumery. 

主要发现：Here, we report a 1.94 Gb chromosome-scale assembly of the patchouli genome (contig N50 = 7.97 Mb). 

结果1-基因扩张：The gene annotation reveals that tandem duplication of sesquiterpene biosynthetic genes may be a major contributor to the biosynthesis of patchouli bioactivity components. 

结果2-亚基因组：We further phase the genome into two distinct subgenomes (A and B), and identify a chromosome substitution event that have occurred between them. 

结果3-TE插入：Further investigations show that a burst of universal LTR-RTs in the A subgenome lead to the divergence between two subgenomes. However, no significant subgenome dominance is detected. 

结果4-基因组演化：Finally, we track the evolutionary scenario of patchouli including whole genome tetraploidization, subgenome divergency, hybridization, and chromosome substitution, which are the key forces to determine the complexity of patchouli genome. 

结论：Our work sheds light on the evolutionary history of patchouli and offers unprecedented genomic resources for fundamental patchouli research and elite germplasm development.

 摘 要 

广藿香是唇形科中一种重要的芳香植物，被广泛用于医药和香水。本文中，作者报道了广藿香1.94Gb的染色体级别基因组组装，其中contig N50 长7.97 Mb。基因注释显示倍半萜生物合成基因的串联重复可能是广藿香中生物活性组分生物合成的重要贡献者。作者进一步将广藿香基因组拆分成了两套基因组，分别为A和B亚基因组，并且鉴定了两套基因组之间的染色体替换事件。进一步的分析显示，A基因组上爆发了一次广泛的LTR-RTs插入事件，导致了两个亚基因组之间的分化。但是，并未在A和B亚基因组之间发现存在优势基因组。最终，作者追踪了广藿香的基因组演化轨迹，包括全基因组四倍化、亚基因组分化、杂交以及染色体替换，这些都是决定广藿香基因组复杂性的关键因素。本文的研究结果为广藿香的演化历史提供了新的视野，同时也为广藿香基础研究以及优异种质开发提供了珍贵的基因组资源。

 王宏斌