The large mimosoid genus Inga Mill. (tribe Ingeae, Caesalpinioideae) is nodulated by diverse Bradyrhizobium strains in its main centers of diversity in Brazil

TY - JOUR

T1 - The large mimosoid genus Inga Mill. (tribe Ingeae, Caesalpinioideae) is nodulated by diverse Bradyrhizobium strains in its main centers of diversity in Brazil

AU - Rhem, Mariana Ferreira Kruschewsky

AU - Silva, Verônica Cordeiro

AU - dos Santos, José Miguel Ferreira

AU - Zilli, Jerri Édson

AU - James, Euan K.

AU - Fragomeni Simon, Marcelo

AU - Gross, Eduardo

N1 - Funding Information: The authors thank to Patricia A. Casaes and Lander J. Alves for help in nodule collections. We also thank to FAPESB for the scholarship granted to MFK Rhem, to CNPq (grant number 483581/2013-5) for the financial support, to the Postgraduate Program in Biology and Biotechnology of Microorganisms and to the State University of Santa Cruz for the infrastructure. Publisher Copyright: © 2021 Elsevier GmbH

PY - 2021/11

Y1 - 2021/11

N2 - Inga (Caesalpinioideae) is the type genus of the Ingeae tribe in the mimosoid clade. It comprises about 300 species, all trees or treelets, and has an exclusively neotropical distribution, with Brazil as its main center of diversity. In this study, we analyzed the diversity of 40 strains of rhizobia isolated from root nodules collected from ten species of Inga belonging to different types of vegetation in Brazil. Sequences of their housekeeping genes (dnaK, recA, rpoB, gyrB and glnII), 16S rRNA genes, internal transcribed spacer (ITS) regions, as well as their symbiosis-essential genes (nodC and nifH) were used to characterize them genetically. The ability of the rhizobia to form nodules on Inga spp., and on the promiscuous legume siratro (Macroptilium atropurpureum) was also evaluated. A multilocus sequence analysis (MLSA) combined with an analysis of the ITS region showed that the isolates were distributed into four main groups (A-D) within the large genus Bradyrhizobium. Analysis of the nodC and nifH genes showed that the isolates formed a separate branch from all described species of Bradyrhizobium, except for B. ingae. Most of the tested isolates formed nodules on siratro and all isolates tested nodulated Inga spp. Our results suggest a unique co-evolutionary history of Bradyrhizobium and Inga and demonstrate the existence of potential new species of microsymbionts nodulating this important and representative genus of leguminous tree from the Caesalpinioideae mimosoid clade.

AB - Inga (Caesalpinioideae) is the type genus of the Ingeae tribe in the mimosoid clade. It comprises about 300 species, all trees or treelets, and has an exclusively neotropical distribution, with Brazil as its main center of diversity. In this study, we analyzed the diversity of 40 strains of rhizobia isolated from root nodules collected from ten species of Inga belonging to different types of vegetation in Brazil. Sequences of their housekeeping genes (dnaK, recA, rpoB, gyrB and glnII), 16S rRNA genes, internal transcribed spacer (ITS) regions, as well as their symbiosis-essential genes (nodC and nifH) were used to characterize them genetically. The ability of the rhizobia to form nodules on Inga spp., and on the promiscuous legume siratro (Macroptilium atropurpureum) was also evaluated. A multilocus sequence analysis (MLSA) combined with an analysis of the ITS region showed that the isolates were distributed into four main groups (A-D) within the large genus Bradyrhizobium. Analysis of the nodC and nifH genes showed that the isolates formed a separate branch from all described species of Bradyrhizobium, except for B. ingae. Most of the tested isolates formed nodules on siratro and all isolates tested nodulated Inga spp. Our results suggest a unique co-evolutionary history of Bradyrhizobium and Inga and demonstrate the existence of potential new species of microsymbionts nodulating this important and representative genus of leguminous tree from the Caesalpinioideae mimosoid clade.

KW - Mimosoid clade

KW - MLSA

KW - Phylogeny

KW - Rhizobia

KW - Symbiotic genes

UR - https://www.scopus.com/pages/publications/85116878427

U2 - 10.1016/j.syapm.2021.126268

DO - 10.1016/j.syapm.2021.126268

M3 - Article

C2 - 34649028

AN - SCOPUS:85116878427

SN - 0723-2020

VL - 44

JO - Systematic and Applied Microbiology

JF - Systematic and Applied Microbiology

IS - 6

M1 - 126268

ER -