Soil Microorganisms and Nutrient Under Varies Environments and Cultivation Patterns Influence the Accumulation of Saikosaponin in Bupleurum chinense DC

Materials and methods Variability in environmental conditions and agricultural practices frequently influence the quality of the traditional Chinese medicine, ChaiHu. In this study, we utilized 16S rRNA sequencing and UPLC-MS based metabolomics to investigate the structure and compositional diversity of rhizosphere soil microbiota, as well as to profile the terpenes in ChaiHu samples retrieved from six disparate localities with varied cultivation methods and soil characteristics. Additionally, we characterized the physicochemical properties of the soil samples under investigation. Results A total of 130 terpene metabolites were identified in the metabolome of ChaiHu, including 43 Triterpene Saponin, 34 Sesquiterpenoids, 25 Triterpene, 19 Monoterpenoids, 8 Ditepenoids and 1 Terpene. The predominant beneficial bacterium was Haliangium, benzoxazinones, Gaiella, Sphingomonas and Gemmatimonas within the rhizosphere soil of ChaiHu. Subsequently, Gemmatimonas exhibited a significant correlation with total nitrogen (TN), available nitrogen (AN), and nitrate nitrogen (NO3-N). Moreover, Nitrogen and Potassium elements were highly correlated with the quality of ChaiHu. Additionally, intercropping mode not only enhance the abundance of beneficial bacterial but also promotes the bacterial diversity expansion. Conclusion Our findings suggests that the abundance of rhizosphere microorganisms and the profile of soil nutrients play a pivotal role in shaping the quality of ChaiHu. Our investigation delivers insights into the quality formation of ChaiHu, providing a theoretical foundation for its optimal cultivation practices.

材料与方法 环境条件与农事操作的差异常对中药材柴胡（ChaiHu）的品质造成影响。本研究采用16S rRNA测序（16S rRNA sequencing）与基于超高效液相色谱-质谱联用（UPLC-MS）的代谢组学技术，对采自6个不同产地、栽培方式及土壤特性各异的柴胡根际土壤微生物群落的结构与组成多样性进行解析，并对柴胡样品中的萜类化合物开展表征分析。此外，本研究还对供试土壤样品的理化性质进行了测定。结果 本研究共在柴胡代谢组中鉴定出130种萜类代谢物，包括43种三萜皂苷（Triterpene Saponin）、34种倍半萜类（Sesquiterpenoids）、25种三萜类（Triterpene）、19种单萜类（Monoterpenoids）、8种二萜类（Ditepenoids）及1种萜类化合物。柴胡根际土壤中的优势有益类群包括海亮菌属（Haliangium）、苯并恶嗪酮类（benzoxazinones）、盖氏菌属（Gaiella）、鞘氨醇单胞菌属（Sphingomonas）与芽单胞菌属（Gemmatimonas）。后续分析显示，芽单胞菌属（Gemmatimonas）与总氮（TN）、有效氮（AN）及硝态氮（NO3-N）均存在显著相关性。此外，土壤氮、钾元素含量与柴胡品质呈显著相关。此外，间作模式不仅可提升有益菌的丰度，还可促进细菌群落多样性的拓展。结论 本研究结果表明，根际微生物丰度与土壤养分特征在调控柴胡品质形成过程中发挥关键作用。本研究为解析柴胡品质形成机制提供了新视角，同时为其优质栽培技术的优化提供了理论依据。