Institute of Chinese Medicine Resources, Hunan Academy of Chinese Medicine, Changsha, Hunan, China.
Colleges of Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China.
PeerJ. 2024 Jul 9;12:e17699. doi: 10.7717/peerj.17699. eCollection 2024.
(Mill.) Druce is a traditional Chinese herb that is widely cultivated in China. Polysaccharides are the major bioactive components in rhizome of and have many important biological functions.
To better understand the regulatory mechanisms of polysaccharide accumulation in rhizomes, the rhizomes of two cultivars 'Y10' and 'Y11' with distinct differences in polysaccharide content were used for transcriptome and metabolome analyses, and the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were identified.
A total of 14,194 differentially expressed genes (DEGs) were identified, of which 6,689 DEGs were down-regulated in 'Y10' compared with those in 'Y11'. KEGG enrichment analysis of the down-regulated DEGs revealed a significant enrichment of 'starch and sucrose metabolism', and 'amino sugar and nucleotide sugar metabolism'. Meanwhile, 80 differentially accumulated metabolites (DAMs) were detected, of which 52 were significantly up-regulated in 'Y11' compared to those in 'Y10'. The up-regulated DAMs were significantly enriched in 'tropane, piperidine and pyridine alkaloid biosynthesis', 'pentose phosphate pathway' and 'ABC transporters'. The integrated metabolomic and transcriptomic analysis have revealed that four DAMs, glucose, beta-D-fructose 6-phosphate, maltose and 3-beta-D-galactosyl-sn-glycerol were significantly enriched for polysaccharide accumulation, which may be regulated by 17 DEGs, including UTP-glucose-1-phosphate uridylyltransferase (), hexokinase (), sucrose synthase (), and UDP-glucose 6-dehydrogenase (). Furthermore, 8 DEGs (, , , ) were identified as candidate genes for the accumulation of glucose and beta-D-fructose 6-phosphate in the proposed polysaccharide biosynthetic pathways, and these two metabolites were significantly associated with the expression levels of 13 transcription factors including , , and . This study provided comprehensive information on polysaccharide accumulation and laid the foundation for elucidating the molecular mechanisms of medicinal quality formation in rhizomes.
（Mill.）Druce 是一种广泛种植在中国的传统中药。多糖是根茎中的主要生物活性成分，具有许多重要的生物学功能。
为了更好地了解多糖在根茎中积累的调控机制，使用两个多糖含量差异明显的品种“Y10”和“Y11”的根茎进行转录组和代谢组分析，鉴定差异表达基因（DEGs）和差异积累代谢物（DAMs）。
共鉴定出 14194 个差异表达基因（DEGs），其中 6689 个 DEGs 在“Y10”中下调。下调 DEGs 的 KEGG 富集分析表明，“淀粉和蔗糖代谢”和“氨基糖和核苷酸糖代谢”显著富集。同时，检测到 80 种差异积累代谢物（DAMs），其中 52 种在“Y11”中显著上调。上调的 DAMs 在“托烷、哌啶和吡啶生物碱生物合成”、“戊糖磷酸途径”和“ABC 转运蛋白”中显著富集。整合代谢组学和转录组学分析表明，葡萄糖、β-D-果糖 6-磷酸、麦芽糖和 3-β-D-半乳糖基-sn-甘油这四种 DAMs 对多糖积累有显著富集作用，可能受 17 个 DEGs的调节，包括尿苷二磷酸葡萄糖-1-磷酸尿苷酰转移酶（）、己糖激酶（）、蔗糖合酶（）和 UDP-葡萄糖 6-脱氢酶（）。此外，在提出的多糖生物合成途径中，鉴定出 8 个 DEGs（、、、）作为葡萄糖和β-D-果糖 6-磷酸积累的候选基因，这两种代谢物与包括、、和在内的 13 个转录因子的表达水平显著相关。本研究为多糖积累提供了全面的信息，为阐明根茎药用品质形成的分子机制奠定了基础。
