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Purpose: Microbial community composition in soil is shaped by land uses. In this study, we aimed to investigate the influences of land uses on functional gene profiles. Methods: The soil was sampled from three different types of land use. The metagenomic DNA was sequenced by Illumina shotgun sequencing. The functional gene profiles were annotated by NR, KEGG, CAZyme, CARD, VFDB and PHI databases. Results: The results showed that agriculture soil showed significantly higher ACE and Chao1 indexes in terms of taxonomic and functional genes composition than that in forest soil and park soil. PCoA and multivariate analysis indicated the influence of land use on taxonomic composition, KEGG ortholog, carbohydrate-active enzymes, antibiotic resistance genes, virulence factors and pathogen-host interaction genes. Mantel test results demonstrated that organic carbon and phosphorus are critical drivers that shape taxonomic and functional gene compositions across different land uses. Human- and phyto-pathogens were indigenously present in soils and their compositions were influenced by land use. Conclusion: Collectively, our data demonstrate that land use impacts soil microbial taxonomic and functional composition via organic carbon and phosphorus, and imply the importance of land use management in soil function and soil health. [ABSTRACT FROM AUTHOR] more...

A reaction intermediate is a key molecular entity that has been used in explaining how starting materials converts into the final products in the reaction, and it is usually unstable, highly reactive, and short-lived. Extensive efforts have been devoted in identifying and characterizing such species via advanced physico-chemical analytical techniques. As an appealing alternative, trapping experiments are powerful tools in this field. This trapping strategy opens an opportunity to discover multicomponent reactions. In this work, we report various highly diastereoselective and enantioselective four-component reactions (containing alcohols, diazoesters, enamines/indoles and aldehydes) which involve the coupling of in situ generated intermediates (iminium and enol). The reaction conditions presented herein to produce over 100 examples of four-component reaction products proceed under mild reaction conditions and show high functional group tolerance to a broad range of substrates. Based on experimental and computational analyses, a plausible mechanism of this multicomponent reaction is proposed. The interception of one chemical intermediate with another intermediate is very challenging, as intermediates may be incompatible or too reactive, but could result in a streamlined method of organic synthesis. Here, the authors demonstrate enantioselective four-component reactions via the coupling of two intermediates. [ABSTRACT FROM AUTHOR] more...