Multi‐Omics Analysis Revealed the Mechanisms of Terpenoid Accumulation in Underground Tissues With Different Morphologies of Curcuma kwangsiensis

Curcuma kwangsiensis S.G. Lee et C.F. Liang, a traditional medicinal plant, has rhizomes (RH) and tuberous roots (TR) listed in the Chinese Pharmacopoeia for distinct therapeutic applications, while fibrous roots (FR) are often discarded. Terpenoids, C. kwangsiensis 's main active components, show unclear differential accumulation patterns among underground tissues with different morphologies. This study aimed to reveal terpenoid differential accumulation patterns and molecular regulatory mechanisms in RH, TR, and FR. A comprehensive analysis combining full‐spectrum non‐targeted metabolomics (UPLC‐MS/MS and GC–MS) with transcriptomics (Iso‐seq and RNA‐seq) was used to establish the terpenoid metabolism‐gene regulatory network. Total terpenoid content in C. kwangsiensis was highest in FR > RH > TR. UPLC‐MS/MS and GC–MS identified 39, 41, and 34 differentially accumulated metabolites (DAMs) in RH versus TR, RH versus FR, and TR versus FR, respectively. Upregulated monoterpenoids and sesquiterpenoids DAMs were higher in RH and FR than TR. Transcriptomics identified 78 differentially expressed genes (DEGs). qRT‐PCR results validated the RNA‐seq findings, showing consistent expression profiles for TPS genes, as well as upstream and downstream genes in the terpenoid backbone biosynthesis. Significant DEGs and the accumulation of DAMs correlations were identified through Pearson correlation analysis. Further Spearman analysis uncovered significant regulatory relationships between 42 WRKY transcription factors and 5 TPS genes. The terpenoid metabolism‐gene regulatory network in C. kwangsiensis was established, elucidating the mechanism of the differential terpenoid accumulation in RH, TR, and FR. These results offer scientific support for improving the quality of C. kwangsiensis 's underground tissues and the high‐value utilization of non‐traditional medicinal parts.