The chromosome-level reference genome of Cinnamomum camphora provides new insights into the angiosperm phylogeny and terpene biosynthesis

다국어 초록 (Multilingual Abstract)

Cinnamomum camphora is widely distributed in southeastern of China and is a representative species of Laurales, which has important ecological and economic values due to its richness in plant secondary metabolites. In this study, the chromosome-level reference genome of C. camphora was published with a genome size of 670.29 Mb, of which contig N50 was 2.41 Mb and scaffold N50 was 60.19 Mb, and the duplicated sequences accounted for about half of the genome. Comparative genomic analysis showed that C. camphora underwent three whole-genome duplication (WGD) events, with the distant WGD event being an ε-replication event shared by angiosperm ancestors; the intermediate WGD event occurring before the divergence of Laurales and Magnoliales (Liriodendron chinense); and the recent event occurring approximately before the divergence within Laurales. In addition, we examined the expression of terpene synthesis-related genes in seven different tissues and found that DXS, DXR and HDR, the key limiting enzymes of the MEP pathway associated with monoterpene synthesis, were highly expressed in flowers. In addition, a total of 83 CcamTPS genes were predicted and annotated in the camphor tree genome, and most of them were highly expressed in leaves, stem tips and bark. The chromosomal-level reference genome of the C. camphora provides new insights into the special evolutionary status of magnoliids and terpene biosynthesis.