title: Sulfur Fertilization Changes the Community Structure of Rice Root-, and Soil- Associated Bacteria.
abstract: Under paddy field conditions, biological sulfur oxidation occurs in the oxidized surface soil layer and rhizosphere, in which oxygen leaks from the aerenchyma system of rice plants. In the present study, we examined community shifts in sulfur-oxidizing bacteria associated with the oxidized surface soil layer and rice roots under different sulfur fertilization conditions based on the 16S ribosomal RNA (rRNA) gene in order to explore the existence of oligotrophic sulfur-oxidizing bacteria in the paddy rice ecosystem. Rice plants were grown in pots with no fertilization (control) or CaCO3 or CaSO4 fertilization. A principal-coordinates analysis (PCoA) showed that CaSO4 fertilization markedly affected bacterial communities associated with rice roots and soil, whereas no significant differences were observed in plant growth among the fertilizer treatments examined. In rice roots, the relative abundance of Acidobacteria, Alphaproteobacteria, Gammaproteobacteria, and TM7 was significantly higher in CaSO4-fertilized pots than in control pots. Alphaproteobacteria, Bradyrhizobiaceae, and Methylocystaceae members were significantly more abundant in CaSO4-fertilized roots than in control roots. On the other hand, the abundance of Actinobacteria and Proteobacteria was lower in CaSO4-fertilized soil than in control soil. These results indicate that the bacteria associated with rice roots and soil responded to the sulfur amendment, suggesting that more diverse bacteria are involved in sulfur oxidation in the rice paddy ecosystem than previously considered.
authors.affiliation: Graduate School of Life Sciences, Tohoku University.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Masuda
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Bao
authors.forename: Takashi
authors.initials: T
authors.lastname: Okubo
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sasaki
authors.forename: Seishi
authors.initials: S
authors.lastname: Ikeda
authors.forename: Ryo
authors.initials: R
authors.lastname: Shinoda
authors.forename: Mizue
authors.initials: M
authors.lastname: Anda
authors.forename: Ryuji
authors.initials: R
authors.lastname: Kondo
authors.forename: Yumi
authors.initials: Y
authors.lastname: Mori
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Minamisawa
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D058448:Biota / Q000187:drug effects*; D002133:Calcium Sulfate / Q000378:metabolism; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005308:Fertilizers; D012275:Oryza / Q000382:microbiology*; D018517:Plant Roots / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013455:Sulfur / Q000378:metabolism*
chemical_list: D004275:DNA, Ribosomal; D005308:Fertilizers; D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D002133:Calcium Sulfate