Root exudate chemistry affects soil carbon mobilization via microbial community reassembly  

作　　者：Tao Wen Guang-Hui Yu Wen-Dan Hong Jun Yuan Guo-Qing Niu Peng-Hao Xie Fu-Sheng Sun Lao-Dong Guo Yakov Kuzyakov Qi-Rong Shen 

机构地区：[1]The Key Laboratory of Plant Immunity,Jiangsu Provincial Key Lab for Organic Solid Waste Utilization,Jiangsu Collaborative Innovation Center for Solid Organic Wastes,Educational Ministry Engineering Center of Resource-saving fertilizers,Nanjing Agricultural University,Nanjing 210095,China [2]Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station,Tianjin 300072,China [3]School of Freshwater Sciences,University of Wisconsin-Milwaukee,600 E Greenfield Ave.,Milwaukee,WI 53204,United States [4]Department of Soil Science of Temperate Ecosystems,Department of Agricultural Soil Science,University of Gottingen,Göttingen 37073,Germany [5]Agro-Technological Institute,Peoples Friendship University of Russia(RUDN University),Moscow 117198,Russia

出　　处：《Fundamental Research》2022年第5期697-707,共11页自然科学基础研究（英文版）

基　　金：supported by National Natural Science Foundation of China(Grants No.31902107 and 41977271);Natural Science Foundation of Jiangsu Province(Grant No.BK20211577);the Innovative Research Team Development Plan of the Ministry of Education of China(Grant No.IRT_17R56);supported by Qing Lan Project of Jiangsu Province;the support by the RUDN University Strategic Academic Leadership Program;the WeChat subscription ID“meta-Genome”and“Micro-Bioinformatics and microflora”for the analysis methods.

摘　　要：Plant roots are one of the major mediators that allocate carbon captured from the atmosphere to soils as rhizodeposits,including root exudates.Although rhizodeposition regulates both microbial activity and the biogeochemical cycling of nutrients,the effects of particular exudate species on soil carbon fluxes and key rhizosphere microorganisms remain unclear.By combining high-throughput sequencing,q-PCR,and NanoSIMS analyses,we characterized the bacterial community structure,quantified total bacteria depending on root exudate chemistry,and analyzed the consequences on the mobility of mineral-protected carbon.Using well-controlled incubation experiments,we showed that the three most abundant groups of root exudates(amino acids,carboxylic acids,and sugars)have contrasting effects on the release of dissolved organic carbon(DOC)and bioavailable Fe in an Ultisol through the disruption of organo-mineral associations and the alteration of bacterial communities,thus priming organic matter decomposition in the rhizosphere.High resolution(down to 50 nm)NanoSIMS images of mineral particles indicated that iron and silicon colocalized significantly more organic carbon following amino acid inputs than treatments without exudates or with carboxylic acids.The application of sugar strongly reduced microbial diversity without impacting soil carbon mobilization.Carboxylic acids increased the prevalence of Actinobacteria and facilitated carbon mobilization,whereas amino acid addition increased the abundances of Proteobacteria that prevented DOC release.In summary,root exudate functions are defined by their chemical composition that regulates bacterial community composition and,consequently,the biogeochemical cycling of carbon in the rhizosphere.

关 键 词：Microbial community assembly NanoSIMS imaging Priming effects Root exudate chemistry Soil organic carbon Rhizosphere processes 

分 类 号：X17[环境科学与工程—环境科学]