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Transcriptional analysis of genes involved in nodulation in soybean roots inoculated with Bradyrhizobium japonicum strain CPAC 15

Gesiele Almeida Barros de Carvalho12, Jesiane Stefânia Silva Batista1, Francismar Corrêa Marcelino-Guimarães1, Leandro Costa do Nascimento3 and Mariangela Hungria1*

Author Affiliations

1 Empresa Brasileira de Pesquisa Agropecuária, CNPSo, PO Box 231, Londrina, Paraná 86001-970, Brazil

2 Department of Biochemistry and Biotechnology, Universidade Estadual de Londrina, PO Box 6001, Londrina, Paraná 86051-990, Brazil

3 Laboratório de Genômica e Expressão, Institute of Biology, Universidade Estadual de Campinas, Rua Monteiro Lobato, 255, Campinas, São Paulo 13083-862, Brazil

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BMC Genomics 2013, 14:153  doi:10.1186/1471-2164-14-153

Published: 6 March 2013



Biological nitrogen fixation in root nodules is a process of great importance to crops of soybean [Glycine max (L.) Merr.], as it may provide the bulk of the plant’s needs for nitrogen. Legume nodulation involves several complex steps and, although studied for many decades, much remains to be understood.


This research aimed at analyzing the global expression of genes in soybean roots of a Brazilian cultivar (Conquista) inoculated with Bradyrhizobium japonicum CPAC 15, a strain broadly used in commercial inoculants in Brazil. To achieve this, we used the suppressive subtractive hybridization (SSH) technique combined with Illumina sequencing. The subtractive library (non-inoculated x inoculated) of soybean roots resulted in 3,210 differentially expressed transcripts at 10 days after inoculation were studied. The data were grouped according to the ontologies of the molecular functions and biological processes. Several classes of genes were confirmed as related to N2 fixation and others were reported for the first time.


During nodule formation, a higher percentage of genes were related to primary metabolism, cell-wall modifications and the antioxidant defense system. Putative symbiotic functions were attributed to some of these genes for the first time.

Subtractive library; Differential expression of genes; Nodulation