Discovery of Key Genes for Sterol Biosynthesis in Stellaria dichotoma var. lanceolata Based on Transcriptome Data
Sterol biosynthesis in Stellaria dichotoma var. lanceolata remains poorly characterized despite the medicinal value of its sterol constituents. This study integrated high-performance liquid chromatography (HPLC) quantification of sterols across root, stem, leaf, and flower tissues with full-length transcriptome sequencing and comparative transcriptomics. A total of 372,483 high-quality full-length transcripts were assembled, of which 128,646 were annotated. Differential expression analysis revealed 43,354 genes shared across all four tissues (50.02% of total genes), with 9,647 differentially expressed genes (DEGs) between root and flower, 12,143 between root and leaf, and only 388 between leaf and stem. Weighted gene coexpression network analysis (WGCNA) identified 43 coexpression modules, and the MEblue module contained six key enzyme genes: NP_NY_transcript_168676 (FPPS), NP_NY_transcript_335811 (SQS), NP_NY_transcript_44001 (SQS), NP_NY_transcript_246835 (CAS), NP_NY_transcript_328932 (CAS), and NP_NY_transcript_183565 (GPPS). RT-qPCR validation confirmed expression trends consistent with transcriptome data. These findings provide a foundation for elucidating the biosynthetic pathway and molecular regulation of sterols in S. dichotoma var. lanceolata.