An arbuscular mycorrhizal fungus significantly modifies the soil bacterial community and nitrogen cycling during litter decomposition

Nowadays, due to the expansion of agricultural borders, it is highly desirable to increase the sustained productivity of sugarcane cultivars using the knowledge of soil microbial communities. In this study, twelve shotgun metagenomic datasets based on genomic DNA from soil were analyzed using the Metagenomics Rapid Annotation using Subsystem Technology (MG-RAST) and Statistical Analysis of Metagenomic Profiles (STAMP) to assess differential responses for the total soil bacterial community composition and nitrogen-cycling microbial community functional potential in soils from sugarcane field with pre-harvest burning and adjacent forest in dry and wet seasons in Southeast Brazil. The soil bacterial community revealed higher abundance for Actinobacteria in forest soil than sugarcane soil in dry and wet seasons, and an opposite pattern for Proteobacteria and Planctomycetes in these soils in both seasons. The results obtained in this study based on the KEEG map suggest that the forest soil has a higher nitrogen-cycling microbial community functional potential compared to the sugarcane soil, independently of the season. The gene sequences associated with carbohydrate metabolism were the most frequent in all soil metagenomes. Taken together, the results confirm previous findings regarding the effects of forest conversion to sugarcane production area, providing new insights regarding to this conversion through the prism of the seasonality and pre-harvesting method on microbially mediated nitrogen cycle in sugarcane production fields.

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Interactions between an arbuscular mycorrhizal fungus and a soil microbial community mediating litter decomposition

FEMS Microbiology Ecology ◽

10.1111/j.1574-6941.2011.01292.x ◽

2012 ◽

Vol 80 (1) ◽

pp. 236-247 ◽

Cited By ~ 117

Author(s):

Donald J. Herman ◽

Mary K. Firestone ◽

Erin Nuccio ◽

Angela Hodge

Keyword(s):

Microbial Community ◽

Litter Decomposition ◽

Soil Microbial Community ◽

Arbuscular Mycorrhizal Fungus ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Soil Microbial

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High Salinity Inhibits Soil Bacterial Community Mediating Nitrogen Cycling

Applied and Environmental Microbiology ◽

10.1128/aem.01366-21 ◽

2021 ◽

Author(s):

Xiang Li ◽

Achen Wang ◽

Wenjie Wan ◽

Xuesong Luo ◽

Liuxia Zheng ◽

...

Keyword(s):

Bacterial Community ◽

Variable Selection ◽

Nitrogen Cycling ◽

Community Composition ◽

Community Assembly ◽

High Salinity ◽

Bacterial Community Composition ◽

Soil Bacterial Community ◽

Saline Soils ◽

Soil Bacterial

Salinization is considered as a major threat to soil fertility and agricultural productivity throughout the world. Soil microbes play a crucial role in maintaining ecosystem stability and function (e.g., nitrogen cycling). However, the response of bacterial community composition and community-level function to soil salinity remains uncertain. Herein, we used multiple statistical analyses to assess the effect of high salinity on bacterial community composition and potential metabolism function in the agricultural ecosystem. Results showed that high salinity significantly altered bacterial both alpha (Shannon-Wiener index and phylogenetic diversity) and beta diversity. Salinity, TN, and SOM were the vital environmental factors shaping bacterial community composition. The relative abundance of Actinobacteria , Chloroflexi , Acidobacteria , and Planctomycetes decreased with salinity, whereas Proteobacteria and Bacteroidetes increased with salinity. The modularity and the ratio of negative to positive links remarkedly decreased indicated that high salinity destabilized bacterial networks. Variable selection, which belongs to deterministic processes, mediated bacterial community assembly within the saline soils. Function prediction results showed that the key nitrogen metabolism (e.g., ammonification, nitrogen fixation, nitrification, and denitrification processes) was inhibited in high salinity habitats. Miseq sequencing of 16S rRNA genes revealed that the abundance and composition of nitrifying community were influenced by high salinity. The consistency of function prediction and experimental verification demonstrated that high salinity inhibited soil bacterial community mediating nitrogen cycling. Our study provides strong evidence for salinity effect on the bacterial community composition and key metabolism function, which could help us understand how soil microbe responds to ongoing environment perturbation. IMPORTANCE Revealing the response of the soil bacterial community to external environmental disturbances is an important but poorly understood topic in microbial ecology. In this study, we evaluated the effect of high salinity on the bacterial community composition and key biogeochemical processes in salinized agricultural soils (0.22 to 19.98 dS m −1 ). Our results showed that high salinity significantly decreased bacterial diversity, altered bacterial community composition, and destabilized bacterial network. Moreover, variable selection (61-66%) mediated bacterial community assembly within the saline soils. Functional prediction combined with microbiological verification proved that high salinity inhibited soil bacterial community mediating nitrogen turnover. Understanding the impact of salinity on soil bacterial community is of great significance in managing saline soils and maintaining a healthy ecosystem.

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