Evidence for niche differentiation of nitrifying communities in grassland soils after 44 years of different field fertilization scenarios  

作　　者：Zhongjun JIA Xue ZHOU Weiwei XIA Dario FORNARA Baozhan WANG Elizabeth Anne WASSON Peter CHRISTIE Martin F.POLZ David D.MYROLD 

机构地区：[1]State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008(China) [2]State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098(China) [3]Jiangsu Key Laboratory of Agricultural Meteorology,College of Applied Meteorology,Nanjing University of Information Science and Technology,Nanjing 210044(China [4]Agri-Food and Biosciences Institute,Belfast BT95PX(UK) [5]Department of Civil and Environmental Engineering,Massachusetts Institute of Technology,Cambridge MA 02139(USA) [6]Department of Crop and Soil Science,Oregon State University,Corvallis OR 97331(USA)

出　　处：《Pedosphere》2020年第1期87-97,共11页土壤圈（英文版）

基　　金：the National Natural Science Foundation of China(Nos.41530857 and 41471208);the National Key Basic Research Program of China(No.2015CB150501);the Department of Agriculture,Environment,and Rural Affairs(DAERA)in Northern Ireland,UK(No.700141499);the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB15040000);the Startup Foundation for Introducing Talent of the Nanjing University of Information Science and Technology(NUIST),China(No.S8113117001).

摘　　要：Long-term nitrogen(N)fertilization imposes strong selection on nitrifying communities in agricultural soil,but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly understood.Using a 44-year grassland fertilization experiment,we investigated community shifts of active nitrifiers by DNA-based stable isotope probing(SIP)of field soils that received no fertilization(CK),high levels of organic cattle manure(HC),and chemical N fertilization(CF).Incubation of DNA-SIP microcosms showed significant nitrification activities in CF and HC soils,whereas no activity occurred in CK soils.The 44 years of inorganic N fertilization selected only 13C-ammonia-oxidizing bacteria(AOB),whereas cattle slurry applications created a niche in which both ammonia-oxidizing archaea(AOA)and AOB could be actively13C-labeled.Phylogenetic analysis indicated that Nitrosospira sp.62-like AOB dominated inorganically fertilized CF soils,while Nitrosospira sp.41-like AOB were abundant in organically fertilized HC soils.The 13C-AOA in HC soils were affiliated with the 29i4 lineage.The 13C-nitrite-oxidizing bacteria(NOB)were dominated by both Nitrospira-and Nitrobacter-like communities in CF soils,and the latter was overwhelmingly abundant in HC soils.The 13C-labeled nitrifying communities in SIP microcosms of CF and HC soils were largely similar to those predominant under field conditions.These results provide direct evidence for a strong selection of distinctly active nitrifiers after 44 years of different fertilization regimes in the field.Our findings imply that niche differentiation of nitrifying communities could be assessed as a net result of microbial adaption over 44 years to inorganic and organic N fertilization in the field,where distinct nitrifiers have been shaped by intensified anthropogenic N input.Long-term nitrogen（N） fertilization imposes strong selection on nitrifying communities in agricultural soil, but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly understood. Using a 44-year grassland fertilization experiment, we investigated community shifts of active nitrifiers by DNA-based stable isotope probing（SIP） of field soils that received no fertilization（CK）, high levels of organic cattle manure（HC）, and chemical N fertilization（CF）. Incubation of DNA-SIP microcosms showed significant nitrification activities in CF and HC soils, whereas no activity occurred in CK soils. The 44 years of inorganic N fertilization selected only 13C-ammonia-oxidizing bacteria（AOB）, whereas cattle slurry applications created a niche in which both ammonia-oxidizing archaea（AOA） and AOB could be actively13C-labeled. Phylogenetic analysis indicated that Nitrosospira sp. 62-like AOB dominated inorganically fertilized CF soils, while Nitrosospira sp. 41-like AOB were abundant in organically fertilized HC soils. The 13C-AOA in HC soils were affiliated with the 29i4 lineage. The 13C-nitrite-oxidizing bacteria（NOB） were dominated by both Nitrospira-and Nitrobacter-like communities in CF soils, and the latter was overwhelmingly abundant in HC soils. The 13C-labeled nitrifying communities in SIP microcosms of CF and HC soils were largely similar to those predominant under field conditions. These results provide direct evidence for a strong selection of distinctly active nitrifiers after 44 years of different fertilization regimes in the field. Our findings imply that niche differentiation of nitrifying communities could be assessed as a net result of microbial adaption over 44 years to inorganic and organic N fertilization in the field, where distinct nitrifiers have been shaped by intensified anthropogenic N input.

关 键 词：ammonia-oxidizing ARCHAEA ammonia-oxidizing BACTERIA community shift long-term FERTILIZATION nitrite-oxidizing BACTERIA nitrogen enrichment stable isotope probing MICROCOSM 

分 类 号：S812.2[农业科学—草业科学]