Responses of the methanogenic pathway and fraction of CH4 oxidization in a flooded paddy soil to rice planting  

作　　者：Yuting YANG Guangbin ZHANG Jing MA Qiong HUANG Haiyang YU Kaifu SONG Xiaoli ZHU Xi MIAO Hua XU 

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]University of Chinese Academy of Sciences,Beijing 100049(China)

出　　处：《Pedosphere》2021年第6期859-871,共13页土壤圈（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2017YFD 0300105);the National Natural Science Foundation of China(Nos.41571232,41671241,and 41877325);the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS;member No.2018349)。

摘　　要：Rice planting(RP)is significant to methane(CH4_(4))emissions from paddy fields,but its effect on the relative contribution of the acetoclastic methanogenesis to total CH4_(4) production(F_(ac))and the fraction of CH4_(4) oxidized(Fox)is poorly understood.To quantify the responses of the F_(ac) and Fox to RP,we investigated CH4_(4) fluxes,CH4_(4) production and oxidation potentials,dissolved CH4_(4) concentrations,and their stable carbon isotopes in a flooded paddy soil.The mcrA and pmoA gene copies were also determined by quantitative polymerase chain reaction(qPCR).Compared with the unplanted soil(control,CK),the seasonal CH4_(4) emissions from the planted soil were significantly enhanced,13.6 times,resulting in large decreases in the CH4_(4) concentrations in the soil solution.This indicated that much more CH4_(4) was released into the atmosphere by the RP than was stored in the soils.Acetoclastic methanogenesis became more important from the tillering stage(TS)to the ripening stage(RS)for the CK,with F_(ac) values increased from 17%-20% to 46%-55%.With RP,the F_(ac) values were enhanced by 10%-20%,and it significantly increased the copy numbers of the mcrA gene at the four rice stages(TS,booting stage(BS),grain-filling stage(GS),and RS).Furthermore,the effect of the RP on the abundance of the mcrA gene was highly concurrent with the effect on the F_(ac) values.At the TS,the Fox values at the soil-water interface were around 50%-75% for the CK,being 15%-20% lower than those of the RP in the rhizosphere.It increased to 65%-100% at the GS,but was reduced by 20%-30% after the RP.These differences might be because the copy numbers of the pmoA gene were significantly raised at the TS while lowered at the GS by the RP.This was further demonstrated by the strong correlations between the effect of the RP on the abundance of the pmoA gene and the effect on the Fox values.These findings suggest that RP markedly impacts on the abundances of the mcrA and pmoA genes,affecting the pathway of CH4_(4) production and the fracti

关 键 词：stable carbon isotope acetoclastic methanogenesis CH_(4)production CH_(4)oxidation mcrA gene pmoA gene rhizosphere soil-water interface 

分 类 号：S511[农业科学—作物学]