Comprehensive Analysis Reveals the Difference in Volatile Oil between var. (Wolff) Shan et Y. Li and the Other Four Medicinal Species.

Volatile oil serves as a traditional antipyretic component of Bupleuri Radix. var. (Wolff) Shan et Y. Li belongs to the genus and is distinguished for its high level of saikosaponins and volatile oils; nonetheless, prevailing evidence remains inconclusive regarding its viability as an alternative resource of other official species. This study aims to systematically compare the volatile oil components of both dried and fresh roots of var. and the four legally available species across their chemical, molecular, bionics, and anatomical structures. A total of 962 compounds were determined via GC-MS from the dried roots; var. showed the greatest differences from other species in terms of hydrocarbons, esters, and ketones, which was consistent with the results of fresh roots and the e-nose analysis. A large number of DEGs were identified from the key enzyme family of the monoterpene synthesis pathway in var. via transcriptome analysis. The microscopic observation results, using different staining methods, further showed the distinctive high proportion of phloem in var. , the structure which produces volatile oils. Together, these pieces of evidence hold substantial significance in guiding the judicious development and utilization of genus resources.