02480nas a2200325   4500000000100000000000100001008004100002260001200043653001100055653002200066653001800088653002000106100001400126700001600140700001800156700001600174700001200190700001800202700001300220700001700233700001600250700001200266700002100278700001800299245011600317300001200433490000800445520168700453022001402140       2023                            d  c02/202310aSalvia10aSalvia rosmarinus10acarnosic acid10agenome assembly1 aDanlu Han1 aWenliang Li1 aZhuangwei Hou1 aChufang Lin1 aYun Xie1 aXiaofang Zhou1 aYuan Gao1 aJunwen Huang1 aJianbin Lai1 aLi Wang1 aLiangsheng Zhang1 aChengwei Yang00aThe chromosome-scale assembly of the Salvia rosmarinus genome provides insight into carnosic acid biosynthesis.  a819-8320 v1133 a<p>Rosemary (Salvia rosmarinus) is considered a sacred plant because of its special fragrance and is commonly used in cooking and traditional medicine. Here, we report a high-quality chromosome-level assembly of the S. rosmarinus genome of 1.11&nbsp;Gb in size; the genome has a scaffold N50 value of 95.5&nbsp;Mb and contains 40 701 protein-coding genes. In contrast to other diploid Labiataceae, an independent whole-genome duplication event occurred in S. rosmarinus at approximately 15 million years ago. Transcriptomic comparison of two S. rosmarinus cultivars with contrasting carnosic acid (CA) content revealed 842 genes significantly positively associated with CA biosynthesis in S. rosmarinus. Many of these genes have been reported to be involved in CA biosynthesis previously, such as genes involved in the mevalonate/methylerythritol phosphate pathways and CYP71-coding genes. Based on the genomes and these genes, we propose a model of CA biosynthesis in S. rosmarinus. Further, comparative genome analysis of the congeneric species revealed the species-specific evolution of CA biosynthesis genes. The genes encoding diterpene synthase and the cytochrome P450 (CYP450) family of CA synthesis-associated genes form a biosynthetic gene cluster (CPSs-KSLs-CYP76AHs) responsible for the synthesis of leaf and root diterpenoids, which are located on S. rosmarinus chromosomes 1 and 2, respectively. Such clustering is also observed in other sage (Salvia) plants, thus suggesting that genes involved in diterpenoid synthesis are conserved in the Labiataceae family. These findings provide new insights into the synthesis of aromatic terpenoids and their regulation.</p>
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