The chromosome-level Melaleuca alternifolia genome provides insights into the molecular mechanisms underlying terpenoids biosynthesis

Understanding the genetic basis of M. alternifolia can also provide useful molecular information that can improve the potential for essential oil yield in breeding. Here, we first reported the genome of M. alternifolia at the chromosome level by incorporating Hi-C, Illumina, and PacBio sequencing to anchor the 331.11 Mb genome assembly into 11 pseudochromosomes with a scaffold N50 value of 31.72 Mb.

Comparative genomic analysis showed that several genes from the M. alternifolia genome may have evolved toward more terpenoids metabolites by artificial or natural selection, including MaSE, MaSDR1, MaKAO, MaGA20ox, MaISPF, MaDXS, MaHMGS, and MaIDI. Metabolomics data showed that sesquiterpenoids and monoterpenoids were the main categories of volatile organic compounds (VOCs), the contents of most of which were significantly higher in leaves than in roots and stems, suggesting that they may contribute to the formation and accumulation of VOCs in the leaves of M. alternifolia.