Stop and smell the grasses: evolution of scent producing genus Cymbopogon

Cymbopogon spp. are grass species widely used around the world as medicinal plants and in various industries for the production of perfumes and pharmaceuticals. Despite their extensive use, there are relatively few studies at the genomic and transcriptomic levels. In this study, transcriptomic data were generated for two species—Cymbopogon flexuosus and Cymbopogon winterianus—to investigate evolutionary aspects and the expression of genes associated with secondary metabolite biosynthesis. The transcriptome assembly revealed a total of 18,286 and 22,458 transcripts for C. flexuosus and C. winterianus, respectively. Furthermore, the reads were mapped against the genomes of related species, including Andropogon gerardii, Sorghum bicolor, Saccharum officinarum, Miscanthus sinensis, Miscanthus lutarioriparius, and Zea mays, to assess their conservation across these genomes. The results indicated which species are more closely related to the Cymbopogon genus and highlighted key differences in metabolic pathways. Two samples of leaves per species (cf1, cf2, cw1, and cw2) were used to extract total RNA and to perform sequencing.

香茅属（Cymbopogon）为禾本科草本植物，在全球范围内被广泛用作药用植物，同时也被多类产业用于香料与药物的生产。尽管该属植物应用广泛，但目前针对其基因组与转录组层面的研究相对较少。本研究针对两种香茅属植物——弯叶香茅（Cymbopogon flexuosus）与爪哇香茅（Cymbopogon winterianus）——生成了转录组数据，以探究其演化特征以及与次生代谢产物生物合成相关基因的表达情况。转录组组装结果显示，弯叶香茅与爪哇香茅的转录本总数分别为18286条与22458条。此外，为评估转录组在近缘物种基因组中的保守性，本研究将测序读段比对至以下物种的基因组：大须芒草（Andropogon gerardii）、高粱（Sorghum bicolor）、甘蔗（Saccharum officinarum）、芒草（Miscanthus sinensis）、五节芒（Miscanthus lutarioriparius）以及玉米（Zea mays）。分析结果明确了与香茅属亲缘关系更近的物种，并揭示了其代谢通路中的关键差异。本研究选取每个物种的两组叶片样本（cf1、cf2、cw1与cw2）进行总RNA提取与测序。