title: Wild peanut Arachis duranensis are nodulated by diverse and novel Bradyrhizobium species in acid soils.
abstract: Aiming at learning the microsymbionts of Arachis duranensis, a diploid ancestor of cultivated peanut, genetic and symbiotic characterization of 32 isolates from root nodules of this plant grown in its new habitat Guangzhou was performed. Based upon the phylogeny of 16S rRNA, atpD and recA genes, diverse bacteria belonging to Bradyrhizobium yuanmingense, Bradyrhizobium elkanii, Bradyrhizobium iriomotense and four new lineages of Bradyrhizobium (19 isolates), Rhizobium/Agrobacterium (9 isolates), Herbaspirillum (2 isolates) and Burkholderia (2 isolates) were defined. In the nodulation test on peanut, only the bradyrhizobial strains were able to induce effective nodules. Phylogeny of nodC divided the Bradyrhizobium isolates into four lineages corresponding to the grouping results in phylogenetic analysis of housekeeping genes, suggesting that this symbiosis gene was mainly maintained by vertical gene transfer. These results demonstrate that A. duranensis is a promiscuous host preferred the Bradyrhizobium species with different symbiotic gene background as microsymbionts, and that it might have selected some native rhizobia, especially the novel lineages Bradyrhizobium sp. I and sp. II, in its new habitat Guangzhou. These findings formed a basis for further study on adaptation and evolution of symbiosis between the introduced legumes and the indigenous rhizobia.
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Jing Yu
authors.initials: JY
authors.lastname: Chen
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China. Electronic address: gujun@scnu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Gu
authors.affiliation: Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, 11340 Mexico, DF, Mexico.
authors.forename: En Tao
authors.initials: ET
authors.lastname: Wang
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Xing Xian
authors.initials: XX
authors.lastname: Ma
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Shi Tong
authors.initials: ST
authors.lastname: Kang
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Ling Zi
authors.initials: LZ
authors.lastname: Huang
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Xue Ping
authors.initials: XP
authors.lastname: Cao
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Liang Bing
authors.initials: LB
authors.lastname: Li
authors.affiliation: School of Life Science, South China Normal University, Guangzhou 510631, China.
authors.forename: Yan Ling
authors.initials: YL
authors.lastname: Wu
mesh_terms: D010367:Arachis / Q000382:microbiology*; D001426:Bacterial Proteins / Q000235:genetics; D044822:Biodiversity; D020369:Bradyrhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D053204:Root Nodules, Plant / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry*; D013559:Symbiosis
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012987:Soil
keywords: Acid soil; Arachis duranensis; Biodiversity; Bradyrhizobium; Housekeeping genes; nodC gene