title: Microbial community analysis of field-grown soybeans with different nodulation phenotypes.
abstract: Microorganisms associated with the stems and roots of nonnodulated (Nod(-)), wild-type nodulated (Nod(+)), and hypernodulated (Nod(++)) soybeans [Glycine max (L.) Merril] were analyzed by ribosomal intergenic transcribed spacer analysis (RISA) and automated RISA (ARISA). RISA of stem samples detected no bands specific to the nodulation phenotype, whereas RISA of root samples revealed differential bands for the nodulation phenotypes. Pseudomonas fluorescens was exclusively associated with Nod(+) soybean roots. Fusarium solani was stably associated with nodulated (Nod(+) and Nod(++)) roots and less abundant in Nod(-) soybeans, whereas the abundance of basidiomycetes was just the opposite. The phylogenetic analyses suggested that these basidiomycetous fungi might represent a root-associated group in the Auriculariales. Principal-component analysis of the ARISA results showed that there was no clear relationship between nodulation phenotype and bacterial community structure in the stem. In contrast, both the bacterial and fungal community structures in the roots were related to nodulation phenotype. The principal-component analysis further suggested that bacterial community structure in roots could be classified into three groups according to the nodulation phenotype (Nod(-), Nod(+), or Nod(++)). The analysis of root samples indicated that the microbial community in Nod(-) soybeans was more similar to that in Nod(++) soybeans than to that in Nod(+) soybeans.
authors.affiliation: Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan. kiwamu@ige.tohoku.ac.jp
authors.forename: Seishi
authors.initials: S
authors.lastname: Ikeda
authors.forename: Lynn Esther E
authors.initials: LE
authors.lastname: Rallos
authors.forename: Takashi
authors.initials: T
authors.lastname: Okubo
authors.forename: Shima
authors.initials: S
authors.lastname: Eda
authors.forename: Shoko
authors.initials: S
authors.lastname: Inaba
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Mitsui
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Minamisawa
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000254:growth & development; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D005658:Fungi / Q000235:genetics* / Q000254:growth & development; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D018547:Plant Stems / Q000382:microbiology; D025341:Principal Component Analysis; D012988:Soil Microbiology; D013025:Glycine max / Q000382:microbiology*; D013045:Species Specificity; D013559:Symbiosis
chemical_list: D004269:DNA, Bacterial; D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer