Objective To investigate the differences in sterol contents and gene transcription levels in different tissues of Stellaria dichotoma var. lanceolata, and explore key enzyme genes related to the biosynthetic pathway of sterols in this plant. Methods The contents of sterols in the roots, stems, leaves and flowers of S. dichotoma var. lanceolata was determined by high-performance liquid chromatography (HPLC). Combined with full-length transcriptome sequencing and comparative transcriptomic analysis, weighted gene coexpression network analysis (WGCNA) was used to mine key enzyme genes associated with sterol biosynthesis. The expression levels of these genes were further validated using RT-qPCR. Results The sterols contents in the roots, stems, leaves, and flowers of S. dichotoma var. lanceolata exhibited significant differences. A total of 372 483 high-quality full-length transcripts were obtained by transcriptome sequencing, of which 128 646 full-length transcripts were successfully annotated. Differential gene analysis revealed that 43 354 genes were expressed across the four tissues (roots, stems, leaves and flowers), accounting for 50.02% of all total genes. There were 9 647 differentially expressed genes (DEGs) between roots and flowers, 12 143 DEGs between roots and leaves, and only 388 DEGs between leaves and stems. A total of 119 key enzyme genes involved in sterol biosynthesis were identified, and 43 gene co-expression modules were identified by WGCNA. In the MEblue module, six key enzyme genes involved in sterol biosynthesis were identified, including 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). The expression levels of the above-mentioned key enzyme genes were validated by RT-qPCR, and the results showed expression trends consistent with those obtained from the transcriptome data. Conclusion This study revealed the key enzyme genes involved in sterol biosynthesis in S. dichotoma L.var. lanceolate, providing a research basis for analyzing the biosynthetic pathways and molecular mechanisms that regulate its active ingredients.

Stellaria dichotoma L.var.lanceolata Bunge  /  transcriptome  /  sterols  /  biosynthesis  /  WGCNA