Comparative Genomics of Aeschynomene Symbionts: Insights into the Ecological Lifestyle of Nod-Independent Photosynthetic Bradyrhizobia

Genes

Damien Mornico¹  Lucie Miché¹  Gilles Béna¹  Nico Nouwen¹  André Verméglio²  David Vallenet³  Alexander A.T. Smith³  Eric Giraud¹  Claudine Mຝigue³ 

[1] IRD-LSTM, UMR113, Campus de Baillarguet, 34398 Montpellier cedex 5, France; E-Mails:;Laboratoire de Bioénergétique Cellulaire, CEA Cadarache, DSV, IBEB, 13108 Saint-Paul-lez-Durance, France; E-Mail:;LABGeM, CEA-Genoscope & CNRS-UMR8030, 91057 Evry, France; E-Mails:

关键词: rhizobia;    genomics;    Bradyrhizobium;    Aeschynomene;    nod-independent;   

DOI  :  10.3390/genes3010035

来源: mdpi

【 摘 要 】

Tropical aquatic species of the legume genus Aeschynomene are stem- and root-nodulated by bradyrhizobia strains that exhibit atypical features such as photosynthetic capacities or the use of a nod gene-dependent (ND) or a nod gene-independent (NI) pathway to enter into symbiosis with legumes. In this study we used a comparative genomics approach on nine Aeschynomene symbionts representative of their phylogenetic diversity. We produced draft genomes of bradyrhizobial strains representing different phenotypes: five NI photosynthetic strains (STM3809, ORS375, STM3847, STM4509 and STM4523) in addition to the previously sequenced ORS278 and BTAi1 genomes, one photosynthetic strain ORS285 hosting both ND and NI symbiotic systems, and one NI non-photosynthetic strain (STM3843). Comparative genomics allowed us to infer the core, pan and dispensable genomes of Aeschynomene bradyrhizobia, and to detect specific genes and their location in Genomic Islands (GI). Specific gene sets linked to photosynthetic and NI/ND abilities were identified, and are currently being studied in functional analyses.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.