title: Quantitative analyses of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) large-subunit genes (cbbL) in typical paddy soils.
abstract: The Calvin cycle is known to be the major pathway for CO2 fixation, but our current understanding of its occurrence and importance in paddy soils is poor. In this study, the diversity of three ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes (cbbLG, cbbLR, cbbM) was investigated by clone library, T-RFLP, qPCR, and enzyme assay in five paddy soils in China. The cbbLG sequences revealed a relatively low level of diversity and were mostly related to the sequences of species from Thiobacillus. In contrast, highly diverse cbbLR and cbbM sequences were dispersed on the phylogenetic trees, and most of them were distantly related to known sequences, even forming separate clusters. Abundances of three cbbL genes ranged from 10(6) to 10(9) copies g(-1) soil, and cbbLR outnumbered cbbM and cbbLG in all soil samples, indicating that cbbLR may play a more important role than other two cbbL genes. Soil properties significantly influenced cbbL diversity in five paddy soils, of which clay content, C/N ratio, CEC, pH, and SOC correlated well with variations in microbial composition and abundance. In summary, this study provided a comparison of three cbbL genes, advancing our understanding of their role in carbon sequestration and nutrient turnover in the paddy soil.
authors.affiliation: State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Ke-Qing
authors.initials: KQ
authors.lastname: Xiao
authors.forename: Peng
authors.initials: P
authors.lastname: Bao
authors.forename: Qiong-Li
authors.initials: QL
authors.lastname: Bao
authors.forename: Yan
authors.initials: Y
authors.lastname: Jia
authors.forename: Fu-Yi
authors.initials: FY
authors.lastname: Huang
authors.forename: Jian-Qiang
authors.initials: JQ
authors.lastname: Su
authors.forename: Yong-Guan
authors.initials: YG
authors.lastname: Zhu
mesh_terms: D001419:Bacteria / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002681:China; D008969:Molecular Sequence Data; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D012274:Ribulosephosphates / Q000378:metabolism; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D012274:Ribulosephosphates; D012987:Soil; C001933:ribulose-1,5 diphosphate; D012273:Ribulose-Bisphosphate Carboxylase
keywords: CO2 fixation; RubisCO; cbbL; paddy soil