Distinct composition patterns of bacterial and fungal communities and biogeochemical cycling genes depend on the vegetation type in arid soil

Abstract

Semi-arid and arid regions account for >40 % of the land area worldwide and provide food resources for the world. Nutrient management by farmer's practices, such as fertilization, improves crop production in semi-arid and arid regions, but this can also affect the composition and function of the soil microbial communities. Therefore, in this research, we have examined the composition of the microbial community and biogeochemical cycling genes in arid soil, subjected to nutrient management by farmer's practices, using high-throughput sequencing and a quantitative-PCR-based chip, Quantitative microbial element cycling (QMEC). Proteobacteria and Acidobacteriota, and Ascomycota dominated the composition of bacterial and fungal communities, respectively. Scrubland soils without nutrient management possessed the lowest Chao1 richness and Shannon diversity of the bacterial community but showed higher average Shannon diversity of the fungal community. Acidobacteriota and Gemmatimonadota, copiotrophic members, were found to have a higher percentage in nutrient-managed soils (cotton, fruit, and vegetables) than the scrubland soils. However, Actinobacteria, autochthonous bacteria, were found to have higher relative abundance in soils from the scrubland than from cotton, fruits, and vegetables. Besides, scrubland soils had a higher relative abundance of Glomeromycota (arbuscular mycorrhizal fungi) to support plant growth in the arid and oligotrophic soils. Vegetable soil microbial communities exhibited a higher potential for biogeochemical cycling than soils used for other vegetation types. In soils from cotton and fruits, the bacterial community was more sensitive to soil properties than the fungal community. Nutrients strongly affected the composition of bacterial and fungal communities in soils from vegetables, while salinity drove the microbial communities in scrubland soils. Our results suggest that vegetation types determined the distinct biodiversity patterns of the microbiota (bacteria and fungi) and associated biogeochemical cycling genes in arid soils.