Metabolomics and transcriptomics provide insights into the flavonoid biosynthesis pathway in the roots of developing Aster tataricus.

Aster tataricus (L.) is an important medicinal plant in China. Its roots are rich in flavonoids, the main medicinal components. However, the molecular basis of flavonoid biosynthesis in the roots of A. tataricus remains unclear. In this study, the content of total flavonoid of A. tataricus roots at different developmental stages was measured first, and the results showed that the content of total flavonoid gradually decreased from September to November, which may be caused by the stagnation of A. tataricus growth due to the decrease in temperature after September. Then, an integrated analysis of transcriptome and metabolome was conducted on five developing stages of A. tataricus roots to identify flavonoid compositions and potential genes involved in flavonoid biosynthesis. A total of 80 flavonoid metabolites, of which 75% were flavonols and flavonoids, were identified in metabolomic analyses, among which isorhamnetin, kaempferol, quercetin, and myricetin were the main skeletons of these flavonoids. Cluster analysis divided these 80 flavonoids into 3 clusters. The compounds in cluster I mainly accumulated in S1, S3, and S5. In cluster II, the relative content of the flavonoid metabolites showed an upward trend from S2 to S4. In cluster III, the flavonoids decreased from S1 to S5. A total of 129 structural genes, including 43 PAL, 23 4CL, 9 C4H, 4 CHS, 18 CHI, 3 F3H, 5 F3'H, 1 F3'5'H, 21 FLS, and 2 FSII, and 65 transcription factors, including 22 AP2/ERF, 7 bHLH, 5 bZIP, 8 MYB, 11 NAC, and 12 WRKY, showed significant correlation with total flavonoid content. Eighteen genes (7 4CL, 5 C4H, 2 CHI, 1 F3H, and 3 FLS) and 30 genes (5 PAL, 9 4CL, 1 C4H, 2 CHI, 1 F3H, 1 DFR, 7 3AT, 1 BZ1, and 3 UGT79B1) were identified as key structural genes for kaempferol and anthocyanins biosynthesis, respectively. Our study provides valuable information for understanding the mechanism of flavonoid biosynthesis in A. tataricus root.

[Comparative analysis of chemical compositions of fruits of Perilla frutescens var. arguta and P. frutescens var. frutescens by pre-column derivatization with GC-MS].

The present study compared the appearance and chemical composition of fruits of Perilla frutescens var. arguta(PFA) and P. frutescens var. frutescens(PFF). VHX-6000 3 D depth of field synthesis technology was applied for the appearance observation. The metabolites were qualitatively and quantitatively analyzed by pre-column derivatization combined with gas chromatography-mass spectrometry(GC-MS). Finally, cluster analysis(CA), principal component analysis(PCA), and orthogonal partial least-squares discriminant analysis(OPLS-DA) were applied for exploring the differences in their chemical compositions. The results indicated that the size and color of PFA and PFF fruits were different. PFF fruits were significantly larger than PFA fruits. The surface color of PFA fruits was brown, while PFF fruits were in multiple colors, such as white, grayish-white, and brown. Amino acids, saccharides, organic acids, fatty acids, and phenolic acids were identified in PFA and PFF fruits. The results of CA, PCA, and OPLS-DA indicated significant differences in the content of components between PFA and PFF fruits. Three metabolites, including D-glucose, rosmarinic acid, and D-fructose, which were significantly higher in PFA fruits than in PFF fruits, were screened out as differential metabolites. Considering the regulation on the content of rosmarinic acid in Perillae Fructus in the Chinese Pharmacopoeia(2020 edition), the medicinal value of PFA fruits is higher than that of PFF. In conclusion, there are differences in appearance and chemical composition between PFA fruits and PFF fruits. These results are expected to provide fundamental data for specifying plant source and quality control of Perillae Fructus.

Integrated transcriptomic and metabolomic data reveal the flavonoid biosynthesis metabolic pathway in Perilla frutescens (L.) leaves.

Perilla frutescens (L.) is an important medicinal and edible plant in China with nutritional and medical uses. The extract from leaves of Perilla frutescens contains flavonoids and volatile oils, which are mainly used in traditional Chinese medicine. In this study, we analyzed the transcriptomic and metabolomic data of the leaves of two Perilla frutescens varieties: JIZI 1 and JIZI 2. A total of 9277 differentially expressed genes and 223 flavonoid metabolites were identified in these varieties. Chrysoeriol, apigenin, malvidin, cyanidin, kaempferol, and their derivatives were abundant in the leaves of Perilla frutescens, which were more than 70% of total flavonoid contents. A total of 77 unigenes encoding 15 enzymes were identified as candidate genes involved in flavonoid biosynthesis in the leaves of Perilla frutescens. High expression of the CHS gene enhances the accumulation of flavonoids in the leaves of Perilla frutescens. Our results provide valuable information on the flavonoid metabolites and candidate genes involved in the flavonoid biosynthesis pathways in the leaves of Perilla frutescens.

Integrated metabolomic and transcriptomic analysis of the anthocyanin regulatory networks in Salvia miltiorrhiza Bge. flowers.

BACKGROUND: The objectives of this study were to reveal the anthocyanin biosynthesis metabolic pathway in white and purple flowers of Salvia miltiorrhiza using metabolomics and transcriptomics, to identify different anthocyanin metabolites, and to analyze the differentially expressed genes involved in anthocyanin biosynthesis. RESULTS: We analyzed the metabolomics and transcriptomics data of S. miltiorrhiza flowers. A total of 1994 differentially expressed genes and 84 flavonoid metabolites were identified between the white and purple flowers of S. miltiorrhiza. Integrated analysis of transcriptomics and metabolomics showed that cyanidin 3,5-O-diglucoside, malvidin 3,5-diglucoside, and cyanidin 3-O-galactoside were mainly responsible for the purple flower color of S. miltiorrhiza. A total of 100 unigenes encoding 10 enzymes were identified as candidate genes involved in anthocyanin biosynthesis in S. miltiorrhiza flowers. Low expression of the ANS gene decreased the anthocyanin content but enhanced the accumulation of flavonoids in S. miltiorrhiza flowers. CONCLUSIONS: Our results provide valuable information on the anthocyanin metabolites and the candidate genes involved in the anthocyanin biosynthesis pathways in S. miltiorrhiza.