Key Laboratory of National Forestry and Grassland Administration On Plant Conservation and Utilization in Southern China & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
BMC Genomics. 2024 Jun 10;25(1):578. doi: 10.1186/s12864-024-10509-6.
Rose myrtle (Rhodomyrtus tomentosa (Ait.) Hassk), is an evergreen shrub species belonging to the family Myrtaceae, which is enriched with bioactive volatiles (α-pinene and β-caryophyllene) with medicinal and industrial applications. However, the mechanism underlying the volatile accumulation in the rose myrtle is still unclear.
Here, we present a chromosome-level genomic assembly of rose myrtle (genome size = 466 Mb, scaffold N50 = 43.7 Mb) with 35,554 protein-coding genes predicted. Through comparative genomic analysis, we found that gene expansion and duplication had a potential contribution to the accumulation of volatile substances. We proposed that the action of positive selection was significantly involved in volatile accumulation. We identified 43 TPS genes in R. tomentosa. Further transcriptomic and TPS gene family analyses demonstrated that the distinct gene subgroups of TPS may contribute greatly to the biosynthesis and accumulation of different volatiles in the Myrtle family of shrubs and trees. The results suggested that the diversity of TPS-a subgroups led to the accumulation of special sesquiterpenes in different plants of the Myrtaceae family.
The high quality chromosome-level rose myrtle genome and the comparative analysis of TPS gene family open new avenues for obtaining a higher commercial value of essential oils in medical plants.
桃金娘（Rhodomyrtus tomentosa（Ait.）Hassk）是桃金娘科的一种常绿灌木，富含具有药用和工业应用价值的生物活性挥发物（α-蒎烯和β-石竹烯）。然而，桃金娘中挥发性物质积累的机制尚不清楚。
在这里，我们呈现了桃金娘的染色体水平基因组组装（基因组大小=466 Mb，支架 N50=43.7 Mb），预测有 35554 个编码蛋白的基因。通过比较基因组分析，我们发现基因扩张和复制可能对挥发性物质的积累有潜在贡献。我们提出，正选择的作用显著参与了挥发性物质的积累。我们在桃金娘中鉴定了 43 个 TPS 基因。进一步的转录组和 TPS 基因家族分析表明，TPS 的不同基因亚组可能对桃金娘科灌木和乔木中不同挥发物的生物合成和积累有很大贡献。结果表明，TPS-a 亚组的多样性导致了不同桃金娘科植物中特殊倍半萜的积累。
高质量的桃金娘染色体水平基因组和 TPS 基因家族的比较分析为获得药用植物中精油的更高商业价值开辟了新途径。
