[Mechanism of differences in terpenoids bewteen different varieties of Chrysanthemi Flos by integrated metabolomics and transcriptomcis analyses].

This study compared the terpenoids among different varieties of Chrysanthemi Flos and explored the molecular mechanisms underlying their accumulation, aiming to provide a basis for elucidating the material basis responsible for the differences in taste, flavor, and efficacy among different varieties. Secondary metabolites of two Chrysanthemi Flos varieties- "Hangju" and "Huaiju" -were analyzed by metabolomics. Key genes were identified from the transcriptome data, and gene expression levels were determined by qRT-PCR. A total of 21 terpenoid-related differential metabolites were identified in "Hangju" and "Huaiju" via metabolomics analysis, including eucalyptol, camphor, γ-terpinene, and α-terpineol. Transcriptomics analysis yielded 21 differentially expressed genes associated with terpenoid biosynthesis. Correlation analysis revealed that ten genes had significantly positive correlations with multiple highly accumulated differential terpenoids in "Huaiju". The qRT-PCR validation showed that the expression trends of the eight enzyme genes involved in terpenoid biosynthesis were consistent with those obtained from transcriptome sequencing in "Hangju" and "Huaiju". This study elucidates the differences in terpenoids and their accumulation mechanisms between the two varieties. It lays a foundation for further revealing the material basis underlying the differences in taste, flavor, and the wind-dispersing and heat-clearing efficacy of the two varieties, as well as for clarifying the regulation of key enzyme genes on differential terpenoids. The results provide a reference for the genetic improvement and high-value utilization of Chrysanthemi Flos germplasm resources.