Plants respond to UV-B irradiation (280–315 nm wavelength) via elaborate metabolic regulatory mechanisms that help them adapt to this stress. To investigate the metabolic response of the medicinal herb Chinese liquorice (Glycyrrhiza uralensis) to UV-B irradiation, we performed liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomic analysis, combined with analysis of differentially expressed genes in the leaves of plants exposed to UV-B irradiation at various time points. Fifty-four metabolites, primarily amino acids and flavonoids, exhibited changes in levels after the UV-B treatment. The amino acid metabolism was altered by UV-B irradiation: the Asp family pathway was activated and closely correlated to Glu. Some amino acids appeared to be converted into antioxidants such as γ-aminobutyric acid and glutathione. Hierarchical clustering analysis revealed that various flavonoids with characteristic groups were induced by UV-B. In particular, the levels of some ortho-dihydroxylated B-ring flavonoids, which might function as scavengers of reactive oxygen species, increased in response to UV-B treatment. In general, unigenes encoding key enzymes involved in amino acid metabolism and flavonoid biosynthesis were upregulated by UV-B irradiation. These findings lay the foundation for further analysis of the mechanism underlying the response of G. uralensis to UV-B irradiation.

This study aims to evaluate the prebiotic potential of polysaccharides derived from Stellariae Radix (SRPs) and explore their influence on the gut microbiota composition in mice. Lactobacillus acidophilus and Bifidobacterium longum were cultivated in an MRS medium, while their growth kinetics, clumping behavior, sugar utilization, pH variation, growth density, and probiotic index were meticulously monitored. Additionally, the impact of crude Stellariae Radix polysaccharides (CSRP) on the richness and diversity of gut microbiota in mice was assessed via 16S rDNA sequencing. The results demonstrated the remarkable ability of CSRPs to stimulate the proliferation of Lactobacillus acidophilus and Bifidobacterium longum. Moreover, the oral administration of CSRPs to mice led to a noticeable increase in beneficial bacterial populations and a concurrent decrease in detrimental bacterial populations within the intestinal flora. These findings provided an initial validation of CSRPs as a promising agent in maintaining the equilibrium of gut microbiota in mice, thereby offering a substantial theoretical foundation for developing Stellariae Radix as a prebiotic ingredient in various applications, including food, healthcare products, and animal feed. Furthermore, this study presented novel insights for the exploration and utilization of Stellariae Radix resources.

Stellaria dichotoma L. var. lanceolata Bge. (S. lanceolata) is a psammophytic plant endemic to the northwest region of China and has now developed into a cultivated economic crop. It is the original plant species used in traditional Chinese medicine as Yinchaihu. Recently, the lack of scientifically guided production zoning has exacerbated the arbitrary introduction and expansion of S. lanceolata cultivation, resulting in significant changes to its habitat and quality. This study utilizes distribution data of wild S. lanceolata along with data from 33 environmental factors to analyze the primary habitat factors influencing the species' distribution using the Maxent model, simulating both current and future suitable production zones. Additionally, amplicon sequencing was employed to investigate changes in rhizospheric soil microorganisms across different cultivation sites and years. Furthermore, metabolomics, near-infrared spectroscopy, and the quantification of active ingredient content were used to assess the effects of various suitable zones on S. lanceolata. The migration trends of S. lanceolata toward the central and eastern regions of Inner Mongolia revealed that elev, bio_4, bio_13, bio_11, and S_clay are the primary ecological and soil factors influencing suitability zoning, contributing a cumulative rate of 80.5%. The rhizosphere microbial environment shifted significantly from high to medium suitability habitats. As cultivation duration increased, the diversity of fungi and bacteria and the functional genera within the rhizosphere exhibited significant changes. Notably, there were substantial alterations in metabolic processes and substance accumulation during the transition from high to medium and low suitability zones, resulting in the identification of 281 and 370 differential metabolites, respectively. Additionally, the near-infrared spectral characteristics and active ingredient content of S. lanceolata in high suitability zones displayed distinct specificity. In particular, the contents of total flavonoids (2.772 mg·g−1), dichotomines B (0.057 mg·g−1), and quercetin-3-O-β-D-glucoside (0.312 mg·g−1) were notably higher, with the overall quality score surpassing that of other suitable zones. This study revealed the key climatic, soil, and rhizosphere microbial environmental factors influencing the quality formation of S. lanceolata and the selection of suitable production zones, offering guidance for sustainable development and production zone planning.