Dataset Information

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling.

ABSTRACT: Despite several lines of observational evidence, there is a lack of consensus on whether higher fungal:bacterial (F:B) ratios directly cause higher soil carbon (C) storage. We employed RNA sequencing, protein profiling and isotope tracer techniques to evaluate whether differing F:B ratios are associated with differences in C storage. A mesocosm (13)C labeled foliar litter decomposition experiment was performed in two soils that were similar in their physico-chemical properties but differed in microbial community structure, specifically their F:B ratio (determined by PLFA analyses, RNA sequencing and protein profiling; all three corroborating each other). Following litter addition, we observed a consistent increase in abundance of fungal phyla; and greater increases in the fungal dominated soil; implicating the role of fungi in litter decomposition. Litter derived (13)C in respired CO2 was consistently lower, and residual (13)C in bulk SOM was higher in high F:B soil demonstrating greater C storage potential in the F:B dominated soil. We conclude that in this soil system, the increased abundance of fungi in both soils and the altered C cycling patterns in the F:B dominated soils highlight the significant role of fungi in litter decomposition and indicate that F:B ratios are linked to higher C storage potential.

SUBMITTER: Malik AA

PROVIDER: S-EPMC4977315 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling.

Malik Ashish A AA Chowdhury Somak S Schlager Veronika V Oliver Anna A Puissant Jeremy J Vazquez Perla G M PG Jehmlich Nico N von Bergen Martin M Griffiths Robert I RI Gleixner Gerd G

Frontiers in microbiology 20160809

Despite several lines of observational evidence, there is a lack of consensus on whether higher fungal:bacterial (F:B) ratios directly cause higher soil carbon (C) storage. We employed RNA sequencing, protein profiling and isotope tracer techniques to evaluate whether differing F:B ratios are associated with differences in C storage. A mesocosm (13)C labeled foliar litter decomposition experiment was performed in two soils that were similar in their physico-chemical properties but differed in mi ...[more]

PMID: 27555839

Similar Datasets

Project description:Salinization is considered 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. Here, 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 both bacterial alpha (Shannon-Wiener index and phylogenetic diversity) and beta diversity. Salinity, total nitrogen (TN), and soil organic matter (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, indicating 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 the 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 a salinity effect on the bacterial community composition and key metabolism function, which could help us understand how soil microbes respond 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 the bacterial network. Moreover, variable selection (61% to 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 for managing saline soils and maintaining a healthy ecosystem.

Project description:Genetic engineering has been used to decrease the lignin content and to change the lignin composition of switchgrass (Panicum virgatum L.) to decrease cell wall recalcitrance to enable more efficient cellulosic biofuel production. Previous greenhouse and field studies showed that downregulation of the gene encoding switchgrass caffeic acid O-methyltransferase (COMT) and overexpression of the switchgrass PvMYB4 (MYB4) gene effectively improved ethanol yield. To understand potential environmental impacts of cultivating these transgenic bioenergy crops in the field, we quantified the effects of field cultivation of transgenic switchgrass on soil organic carbon (SOC) dynamics. Total and active SOC as well as soil respiration were measured in soils grown with two COMT-downregulated transgenic lines (COMT2 and COMT3), three MYB4-overexpressed transgenic lines (L1, L6, and L8), and their corresponding non-transgenic controls. No differences in total SOC, dissolved organic carbon (DOC), and permanganate oxidizable carbon (POXC) were detected between transgenic and non-transgenic treatments for both COMT (10.4-11.1 g kg-1 for SOC, 60.0-64.8 mg kg-1 for DOC, and 299-384 mg kg-1 for POXC) and MYB4 lines (6.89-8.21 g kg-1 for SOC, 56.0-61.1 mg kg-1 for DOC, and 177-199 mg kg-1 for POXC). Soil CO2-carbon (CO2-C) production from the COMT2 transgenic line was not significantly different from its non-transgenic control. In contrast, the COMT3 transgenic line had greater soil CO2-C production than its non-transgenic control (210 vs. 165 µg g-1) after 72 days of laboratory incubation. Combining the improvement in ethanol yield and biomass production reported in previous studies with negligible change in SOC and soil respiration, COMT2 could be a better biofuel feedstock than COMT3 for environmental conservation and cost-effective biofuel production. On the other hand, MYB4 transgenic line L8 produced more biomass and total ethanol per hectare while it released more CO2-C than the control (253 vs. 207 µg g-1). Long-term in situ monitoring of transgenic switchgrass systems using a suite of soil and environmental variables is needed to determine the sustainability of growing genetically modified bioenergy crops.

Dataset Information

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling.

Publications

Soil Fungal:Bacterial Ratios Are Linked to Altered Carbon Cycling.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets