Li Wen-Yan, Li Chang-Zhou, Huang Jing-Li, Zhan Jie, Wang Ai-Qin, Xiao Dong, He Long-Fei
College of Agronomy, Guangxi University, Nanning, 530004, China.
Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning, 530004, China.
BMC Plant Biol. 2025 Sep 1;25(1):1174. doi: 10.1186/s12870-025-07227-w.
The genus Dioscorea is traditional Chinese medicine producing a variety of pharmacological active substances especially saponins. In our study, the secondary metabolism of Dioscorea zingiberensis and D. opposita that have significantly different saponin contents were investigated.
The saponin content was significantly different between two species. KEGG pathway enrichment analysis of transcriptomic data revealed significant differences between the two species in several metabolic pathways, including secondary metabolite biosynthesis, phenylpropanoid biosynthesis, starch and sucrose metabolism, photosynthesis, flavonoid biosynthesis, and steroid biosynthesis. Notably, 28 differentially expressed genes (DEGs) were linked to steroid biosynthesis. Through further metabolome analysis, we detected a total of 1 010 metabolites, and 212 (52 upregulated and 160 downregulated) differential metabolites (DAMs) were screened. The DAMs were mainly enriched in biosynthesis of secondary metabolites (32), amino acids (17), carbon metabolism (10), pentose phosphate (7), phenylalanine metabolism (6), and steroid (2). The combined analysis of transcriptome and metabolome found that terpenoid backbone biosynthesis, flavonoid biosynthesis and steroid biosynthesis were significantly enriched. In addition, we screened three candidate glycosyltransferase genes involved in dioscin biosynthesis.
The integration of transcriptome and metabolome analyses revealed a strong correlation between metabolite contents and gene expression. Three genes, J5N97_024139 (sterol 3-beta-glucosyltransferase 1, UGT80A2), J5N97_022450 (sterol 3-beta-glucosyltransferase 2, UGT80B1) and J5N97_004795 (UDP-rhamnose transporter 1, URT1), were significantly positively correlated with dioscin biosynthesis. These results provide valuable data for the study of secondary metabolites, particularly saponins, and lay a solid foundation for breeding ideal Dioscorea plants.
薯蓣属是传统的中药材，能产生多种药理活性物质，尤其是皂苷。在我们的研究中，对皂苷含量有显著差异的盾叶薯蓣和山药的次生代谢进行了研究。
两个物种的皂苷含量存在显著差异。转录组数据的KEGG通路富集分析显示，两个物种在几个代谢途径上存在显著差异，包括次生代谢物生物合成、苯丙烷类生物合成、淀粉和蔗糖代谢、光合作用、类黄酮生物合成和类固醇生物合成。值得注意的是，28个差异表达基因（DEGs）与类固醇生物合成有关。通过进一步的代谢组分析，我们总共检测到1010种代谢物，并筛选出212种（52种上调和160种下调）差异代谢物（DAMs）。这些DAMs主要富集在次生代谢物生物合成（32种）、氨基酸（17种）、碳代谢（10种）、磷酸戊糖（7种）、苯丙氨酸代谢（6种）和类固醇（2种）中。转录组和代谢组的联合分析发现，萜类骨架生物合成、类黄酮生物合成和类固醇生物合成显著富集。此外，我们筛选出了三个参与薯蓣皂苷生物合成的候选糖基转移酶基因。
转录组和代谢组分析的整合揭示了代谢物含量与基因表达之间的强相关性。三个基因，J5N97_024139（甾醇3-β-葡萄糖基转移酶1，UGT80A2）、J5N97_022450（甾醇3-β-葡萄糖基转移酶2，UGT80B1）和J5N97_004795（UDP-鼠李糖转运蛋白1，URT1），与薯蓣皂苷生物合成显著正相关。这些结果为次生代谢物，特别是皂苷的研究提供了有价值的数据，并为培育理想的薯蓣属植物奠定了坚实的基础。
