Cordyceps sinensis is a precious medicinal and edible fungus, which is widely used in body health care and disease prevention. The current research focuses on the comparison of metabolite characteristics between a small number of samples and lacks a comprehensive evaluation of the quality of C. sinensis in a large-scale space. In this study, LC-MS/MS, principal component analysis (PCA), hierarchical cluster analysis (HCA), and the membership function method were used to comprehensively evaluate the characteristics and quality of metabolites in 15 main producing areas of C. sinensis in China. The results showed that a total of 130 categories, 14 supercategories, and 1718 metabolites were identified. Carboxylic acids and derivatives, fatty acyls, organo-oxygen compounds, benzene and substituted derivatives, prenol lipids, and glycerophospholipids were the main components of C. sinensis. The HCA analysis and KEGG pathway enrichment analysis of 559 differentially accumulated metabolites (DAMs) showed that the accumulation models of fatty acids and conjugates and carbohydrates and carbohydrate conjugates in glycerophospholipid metabolism and arginine and proline metabolism may be one of the reasons for the quality differences in C. sinensis in different producing areas. In addition, a total of 18 biomarkers were identified and validated, which had a significant discrimination effect on the samples (p < 0.05). Overall, YS, BR, and ZD, with the highest membership function values, are rich and balanced in nutrients. They are excellent raw materials for the development of functional foods and provide scientific guidance for consumers to nourish health care.

Fresh and dried Cordyceps sinensis are widely used by the public for medicinal and health purposes. However, the differences between them have not been examined. In this study, fresh wild and artificial C. sinensis (WFC and AFC) were dried to obtain dried wild and artificial C. sinensis (WDC and ADC). Non-targeted GC-MS was used to analyze the metabolic profile characteristics of the four groups of samples. The results showed that air drying significantly altered the composition and content of C. sinensis, mainly in the form of higher abundance of organic acids and derivatives and lower abundance of lipids and lipid-like molecules in fresh C. sinensis. Hierarchical cluster analysis (HCA) and quantitative analyses showed that air drying increased the abundance of Valine, Zinniol, Urocanate, Vulpinic acid, and Uridine 5’-diphosphate, and decreased Xanthotoxol, Vitexin-4-o-glucoside, Val-trp, and Wogonin. These differentially accumulated metabolites (DAMs) were also shown to be potential biomarkers for C. sinensis. KEGG enrichment analysis identified lysine biosynthesis as the most significantly enriched pathway. Annotation of these DAMs to lysine biosynthesis revealed that citrate cycle and pyruvate metabolism entered lysine biosynthesis via 2-oxohlutarate and Homocitrate, respectively, resulting in significant enrichment of L-saccharopine and L-lysine content was significantly higher. Alanine, aspartate, and Glutamate metabolism synthesized more L-aspartate to promote L-lysine synthesis. Thus, high levels of L-lysine result in lysine degradation and pymolysine, which are the most active metabolic pathways during the drying of fresh C. sinensis and indirectly lead to differences in metabolic profiles.

Saussurea plants are widely distributed in Asia and Europe; however, their complex phylogenetic relationships have led to many difficulties in phylogenetic studies and interspecific identification. In this study, we assembled, annotated, and analyzed the chloroplast genomes of three Saussurea plants: Saussurea katochaete, Saussurea superba, and Saussurea stella. The results showed that the full-length sequences of the three Saussurea plants were 152,561 bp, 151,452 bp, and 152,293 bp, respectively, which represent the typical quadripartite structure, and the genomes were relatively conserved. The gene annotation results showed that the chloroplast genomes of S. katochaete, S. superba, and S. stella were annotated with 128, 124, and 127 unique genes, respectively, which included 83, 80, and 83 protein-coding genes (PCGs), respectively, 37, 36, and 36 tRNA genes, respectively, and 8 rRNA genes. Moreover, 46, 45, and 43 SSR loci, respectively, and nine highly variable regions (rpl32-trnL-UAG, rpl32, ndhF-rpl32, ycf1, trnC-GCA-petN, trnC-GCA, rpcL, psbE-petL, and rpl16-trnG-UUG) were identified and could be used as potential molecular markers for population identification and phylogenetic study of Saussurea plants. Phylogenetic analyses strongly support the sisterhood of S. katochaete with S. superba and S. stella, and are all clustered with S. depsagensis, S. inversa, S. medusa, and S. gossipihora, of which S. gossipiphora is most closely related. Additionally, the phylogenetic results indicate a high frequency of differentiation among different species of Saussurea plants, and many different species or genera are morphologically very different from each other, which may be related to certain genetic material in the chloroplasts. This study provides an important reference for the identification of Saussurea plants and studies their evolution and phylogenetics.

Bistorta vivipara is a medicinal plant with a long history, but there are few studies on the effects of its medicinal components and endophytic bacteria on the accumulation of secondary metabolites. Therefore, in this study, non-targeted metabolomics techniques and 16s rDNA techniques were used to study B. vivipara from different regions. A total of 1290 metabolites and 437 differential metabolites were identified from all samples. Among them, flavonoids, isoflavonoids, and benzopyrans are the main medicinal components of B. vivipara; these have potential anticancer, antiviral, and antioxidant properties, as well as potential applications for the treatment of atrial fibrillation. In addition, irigenin, an important medicinal component, was identified for the first time. The endophytic bacterial communities in the root tissues of B. vivipara from different regions were also different in composition and richness. Hierarchical clustering heat map analysis showed that Proteobacteria and Actinobacteriota bacteria significantly affected the accumulation of many medicinal components in the roots of B. vivipara.

During the subculture of filamentous fungi, obvious signs of degradation occur which affect the growth and development of the strain, change the content of metabolites, and interfere with gene expression. However, the specific molecular mechanism of filamentous fungi degradation is still unclear. In this study, a filamentous fungus Samsoniella hepiali was used as the research object, and it was continuously subcultured. The results showed that when the strain was subcultured to the F8 generation, the strain began to show signs of degradation, which was manifested by affecting the apparent morphology, reducing the growth rate and sporulation, and destroying the antioxidant system. Further transcriptome and metabolomics analyses were performed, and the results showed differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) that were mainly enriched in four metabolic pathways: ABC transporters; fatty acid degradation; alanine, aspartate, and glutamate metabolism; and purine metabolism. Many of the metabolites that were significantly enriched in different pathways may mainly be regulated by genes belonging to proteins and enzymes, such as Abcd3, Ass1, and Pgm1. At the same time, in the process of subculture, many genes and metabolites that can induce apoptosis and senescence continue to accumulate, causing cell damage and consuming a lot of energy, which ultimately leads to the inhibition of mycelial growth. In summary, this study clarified the response of S. hepiali strains to key metabolic pathways during subculture and some reasons for the degradation of strains.

Ophiocordyceps sinensis is a medicinal fungus with significant nutritional and utilization value. Temperature is a crucial factor influencing its growth, as temperature changes can impact enzyme activity, metabolite content, and gene expression during fungal cultivation. Currently, there are limited reports on the effects of temperature on the quality of fungal fermentation. This study focuses on O. sinensis and conducts temperature stress culture experiments. The results indicate that the optimal culture temperature range is between 18 and 23 °C, with extreme temperatures negatively affecting the morphology, growth rate, sporulation, and antioxidant systems of the strains. Further metabolomic and transcriptomic analyses revealed that differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were primarily enriched in four metabolic pathways: linoleic acid metabolism, arginine and proline metabolism, and lysine degradation. Many significantly enriched metabolites across various pathways appear to be predominantly regulated by ribosomal and RNA polymerase genes. Furthermore, we cultured O. sinensis mycelium at various temperatures and observed that a significant number of genes and metabolites associated with apoptosis and senescence were expressed at 28 °C. This led to cell damage, excessive energy consumption, and ultimately inhibited mycelial growth. In summary, this study elucidates the response mechanisms of O. sinensis to key metabolic pathways under different temperature growth conditions and explores factors contributing to strain degradation.