Genomic analysis of Bradyrhizobium japonicum E109 the soybean-symbiotic strain most extensively used for inoculant production in Argentina

CASSÁN, FABRICIO; REVALE, SANTIAGO; MANCINI, ESTEFANIA; STIJN, SPAEPEN; VANDERLEYDEN, JOS; PERTICARI, ALEJANDRO

Munich

Congreso; 10th European Nitrogen Fixation Conference; 2012

HelmohltzZentrum Munchen

B. japonicum E109 was selected during 1980s by IMYZA-INTA as the most suitable strain for soybean inoculation in Argentina. Numerous laboratory, greenhouse and field experiments since then have demonstrated the ability of E109 to increase soybean productivity under diverse agronomical conditions by the atmospheric nitrogen fixation mechanism. Furthermore, there are increasing reports on E109 capacity to promote growth in non-legumes and other crops by occurrence of a wide broad of mechanisms different to BNF. In this work, we present a comprehensive analysis of the genomic features and plant growth promotion mechanisms, besides to the well studied symbiotic-nitrogen fixation. The genome sequence was obtained using a Whole Genome Shotgun and a Pair-Ends strategies with a 454 GS FLX Titanium pyrosequencer at INDEAR. Assembly was done using Celera Assembler v7.0 with a 24X genome coverage. A total of 3 scaffolds were obtained. The draft genome was 9,228,187 bases in length with a mean GC content of 63.6%. Genome annotation was done using the Standard Operating Procedures for Prokaryotic annotation from ISGA and from RAST annotation server. A total of 8,822 Coding Sequences (CDS) and 58 structural RNAs were predicted. Annotation covered 534 RAST subsystems with 3,198 CDS (37%), while 3,664 (42%) were classified as hypothetical proteins. The putative nitrogen fixation and metabolism genes of E109 were analyzed and compared with those previously obtained of B. japonicum strain USDA110, Bradyrhizobium sp. strain S23321 and Bradyrhizobium sp. strain BATi1.Comparative analysis was performed by the use of KEGG, RAST and INDEAR web services tools.