ISWC has made new progress in the study of bacterial community structure and soil carbon priming effect patterns
Update time:2022-06-20
Recently, the team of Li Shiqing, a researcher at the Institute of Soil and Water Conservation, has made new progress in the study of bacterial community structure and soil carbon priming effect patterns. The research results were published in Soil Biology & Biochemistry, entitled "Dynamic changes in bacterial community structure are associated with distinct priming effect patterns". Ph.D. Fu Xianheng was the first author, Li Shiqing was the corresponding author, and the State Key Laboratory of Soil Erosion and Dryland Agriculture of Loess Plateau was the first unit.
Soil organic matter (SOM) is part of the essential carbon pools in terrestrial ecosystems that influences productivity and sustainability of agricultural soils. In comparison to soils without any additions, returning agricultural crop residues to the soil could either increase or decrease the release of soil-derived carbon in the form of CO2, which is known as the positive or negative "priming effect" (PE), respectively. PE patterns are influenced by microorganisms utilising various substrates. However, the varied functional traits of keystone taxa and structure traits of the bacterial community associated with the PEs patterns remain elusive. Therefore, we established a microcosm by adding C4 maize residue (C4 plants have a different 13C signature than C3 plants) to C3 soil amended for 120 d to observe the dynamics of PEs. High-throughput sequencing techniques were used to detect the succession of bacteria; keystone taxa were identified using network analysis. Negative PE (early stage) and positive PE (late stage) were observed during residue decomposition. At the end of the incubation, residue with N resulted in a positive PE, while residue alone had a minimal effect on the decomposition of native SOC. Furthermore, the bacterial community structure displayed distinct successions during residue decomposition. Correspondingly, network analysis revealed differences in the keystone taxa between the early and late stages. Bacillus, Streptomyces, Arthrobacter, and Agromyces were the keystone taxa during the early stage, whereas BD2-11 terrestrial, Bacteroidales, Sphingomonadaceae, and Xanthomonadales were the keystone taxa at the late stage. These putative keystone taxa have different functional traits as drivers of community function, thus linking them to either negative or positive PE. In addition, network modules of bacterial communities differed in the early versus late stages and showed different module-trait relationships during PE. Therefore, the different modules are aggregated in response to distinct PE patterns. This study provides deeper insights into the network structure of bacterial community corresponding to PE patterns and highlights the importance of keystone taxa in PE.
This research was financially supported by the National Key R&D Program of China (2021YFD1900700), the Natural Science Basic Research Plan in Shaanxi Province of China (2022JM-103) and the Department of Science and Technology of Shaanxi Province (2020CGHJ-021).
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ISWC has made new progress in the study of bacterial community structure and soil carbon priming effect patterns