Aromatic medicinal plants derive their therapeutic value from complex mixtures of volatile compounds, yet the genetic logic that shapes these chemical profiles has long remained elusive. In a comprehensive multi-omics study, researchers uncovered how genome evolution, specialized metabolites, and microscopic leaf structures jointly determine the quality of Xiangru, a traditional medicinal and edible herb. By integrating chromosome-level genomics with metabolomic and functional analyses, the study reveals how specific genes control monoterpenoid biosynthesis and how their activity is coordinated with the development of glandular trichomes—the tiny structures that produce and store aromatic compounds. These findings provide a mechanistic explanation for natural variation in medicinal aroma and establish a molecular framework for improving herbal quality through targeted breeding.
Volatile monoterpenoids such as thymol and carvacrol are key bioactive components in many medicinal plants, contributing to their antimicrobial, anti-inflammatory, and immunomodulatory properties. In aromatic herbs, these compounds are synthesized and accumulated within glandular trichomes on leaves and flowers. However, most medicinal species lack high-quality genomic resources, making it difficult to link metabolite diversity with underlying genetic regulation. This gap is especially evident in Xiangru , which exists in both wild and cultivated forms that differ markedly in aroma intensity and biomass. Based on these challenges, there is a pressing need to systematically investigate how genome evolution, metabolic pathways, and trichome development interact to shape medicinal quality.
In a study published (DOI: 10.1093/hr/uhaf263) in Horticulture Research in 2025, scientists from Beijing University of Chinese Medicine, Shanghai Jiao Tong University, the China Academy of Chinese Medical Sciences, and collaborating institutions report the first chromosome-level genomes of Mosla chinensis and its cultivated form M. chinensis ‘Jiangxiangru’. Using an integrative approach that combined genomics, transcriptomics, metabolomics, and functional validation, the team uncovered how key biosynthetic genes and transcription factors jointly regulate aroma-producing compounds and trichome formation, explaining long-observed differences in medicinal quality between wild and cultivated plants.
The researchers assembled high-quality genomes for wild M. chinensis , its cultivated counterpart, and a closely related species, revealing that genome structure and gene copy variation play critical roles in aroma formation. Metabolomic analyses showed that the wild plant accumulates higher levels of monoterpenoids, including thymol and carvacrol, which correlate with a greater density of glandular trichomes on leaf surfaces. Functional assays identified five terpene synthase genes responsible for generating diverse monoterpene skeletons, with one gene producing γ-terpinene—the key precursor of major medicinal compounds.
Crucially, the study demonstrated that this biosynthetic pathway is tightly linked to trichome development. Through gene expression profiling, co-expression networks, and molecular assays, the team showed that specific transcription factors simultaneously activate monoterpenoid biosynthetic genes and promote trichome formation. Silencing these genes sharply reduced aroma compound accumulation, confirming their central role. Together, these results reveal a unified regulatory system in which genome evolution, metabolic specialization, and epidermal structure formation converge to define herbal quality.
“Medicinal quality is not determined by chemistry alone—it is encoded in the genome and expressed through plant structure,” said the study’s senior authors. “By connecting chromosome-scale genome variation with metabolite production and trichome development, we were able to explain why wild and cultivated plants differ so strongly in aroma. This integrative framework moves us beyond descriptive chemistry and toward a predictive understanding of medicinal plant quality, which is essential for both conservation and modern breeding.”
The findings offer practical implications for medicinal plant breeding and quality control. By identifying key genes and regulatory modules that simultaneously influence aroma biosynthesis and trichome development, the study provides molecular targets for breeding high-quality, high-yield herbal varieties without relying on extensive chemical screening. The newly generated genome resources also enable more accurate authentication of medicinal materials and reduce the risk of adulteration. Beyond Xiangru , this work establishes a general strategy for dissecting quality traits in aromatic and medicinal plants, paving the way for genomics-assisted improvement of traditional herbal medicines.
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References
DOI
Original Source URL
https://doi.org/10.1093/hr/uhaf263
Funding information
This research was supported by National Key Research and Development Program of China (2023YFC3503901), Natural Science Foundation of China (82404802, 82404785), National Administration of Traditional Chinese Medicine Science and Technology Project (GZY-KJS 2023-032), Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences (CI2024C005YN, CI2023E002), Fundamental Research Funds for the Central public welfare research institutes (ZZ15-YQ-060, ZZXT202417), earmarked fund for CARS(CARS-21), key project at central government level: The ability establishment of sustainable use for valuable Chinese medicine resources (2060302).
About Horticulture Research
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.
Horticulture Research
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Integrative chromosome-level genomics and metabolomics uncover regulatory networks linking monoterpenoid biosynthesis and glandular trichome formation in Mosla chinensis
1-Oct-2025
The authors declare that they have no competing interests.