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Qinghai‐Tibet Plateau is facing a serious environmental and ecological problem of Meadow degradation. Toxic weed invasion is a typical characteristic of grassland degradation. Soil microbial community composition is sensitive to environmental changes; however, the effects of poisonous weed expansion on soil bacterial communities are unclear. Here, we investigated the effects of Stellera chamaejasme L. expansion on the rhizosphere soil bacterial community structure and function using high‐throughput sequencing. The results showed that expansion of Stellera chamaejasme L. changed soil nitrogen(e.g., total nitrogen [TN, −39.02%], available nitrogen [AN, −32.95%]) and other soil nutrients. Redundancy analysis (RDA) and Variance partitioning analysis (VPA) showed that soil nutrients changed, leading to significant changes in the bacterial community structure. The expansion of Stellera chamaejasme L significantly reduced its rhizosphere bacterial alpha diversity, and the beta diversity had significant differences (p < 0.05). Principal coordinates analysis (PCoA) and analysis of similarity (ANOSIM) indicated that the expansion caused significant variations in the rhizosphere bacterial community (R = 0.7037, p < 0.01). The linear discriminant analysis (LDA) effect size (LEfSe) analysis identified 23 biomarkers, most of which were Proteobacteria, indicating that bacteria involved in soil nutrient cycling were better able to survive in the alpine grassland. The Biolog EcoPlate method was used to determine the soil microbial metabolic capacity in different S. chamaejasme expansions. The result showed that heavy expansion had higher carbon source usage ability and microbial diversity index values. Furthermore, it was also found that heavy expansion improved the usage rate of amino acid carbon sources. Tax4Fun prediction analysis further indicated that carbohydrate metabolism, amino acid metabolism, and membrane transport were central metabolic pathways of rhizosphere soil bacteria. Our study found that Stellera chamaejasme L. changed rhizosphere soil nutrient and bacterial community structure during expansion and helped it tolerate harsh conditions by enriching bacterial communities actively involved in carbon and nitrogen metabolism and promoting plant growth. These findings provided evidence to propose effective restoration measures for poisonous grassland degradation. [ABSTRACT FROM AUTHOR]

Background: It is unclear whether gut microbiota (GM) affects the risk of optic neuritis (ON) through the "gut-brain" axis and the "gut-retina" axis. To examine the causal relationship between GM and ON, we conducted Mendelian randomization (MR) study. Methods: Up to 18,340 samples of 24 population-based cohorts were included in genome-wide association study (GWAS) of 196 GM taxa. ON outcomes were selected from the FinnGen GWAS (951 ON cases and 307,092 controls). In addition, the GWAS based on UK Biobank (UKB) (105 ON cases and 456,243 controls) was used for further exploration. Inverse variance weighted (IVW) was carried out to estimate their effects on ON risk and the MR assumptions were evaluated in sensitivity analyses. Results: Among the 196 GM taxa, the IVW results confirmed that Family -Peptococcaceae (P = 2.17 × 10–3), Genus- Hungatella (P = 4.57 × 10–3) and genus-Eubacterium_rectale_group (P = 0.02) were correlated with the risk of ON based on Finngen GWAS. Based on data from UKB, Genus- Eubacterium_hallii_group (P = 1.50 × 10–3) and Genus- Ruminococcaceae_UCG_002 (P = 0.02) were correlated with the risk of ON. At the phylum, class and order levels, no GM taxa were causally related to ON (P > 0.05). Heterogeneity (P > 0.05) and pleiotropy (P > 0.05) analysis confirmed the robustness of the MR results. Conclusion: Our MR findings support the causal effect of specific GM taxa on ON. GM may affect the risk of ON through the "gut-brain" axis and the "gut-retina" axis. However, further research is needed to confirm the relevant mechanism of the relationship between GM and ON. [ABSTRACT FROM AUTHOR]

The fungal strain BS5 was isolated from a soil sample collected in the Tibetan Plateau, which displayed good insecticidal activity and was identified as Talaromyces purpureogenus based on morphological and molecular analysis. This study aimed to evaluate the insecticidal activity and identify the active compound of the strain BS5 against the locust Locusta migratoria manilensis. The insecticidal activity of the fermented broth of BS5 was at 100% after 7 days against locusts. We extracted the fermented broth of BS5 and then evaluated the insecticidal activity of the extracts against locusts. The ethyl acetate extract exhibited promising activity levels with an LC50 value of 1077.94 μg/mL and was separated through silica gel column chromatography. The UPLC-Q-Exactive Orbitrap/MS system was employed to analyze the active fraction Fr2.2.2 (with an LC50 value of 674.87 μg/mL), and two compounds were identified: phellamurin and rubratoxin B. [ABSTRACT FROM AUTHOR]