Genomic analysis of diazotrophic Azospirillum brasilense Az39 the most extensively used strain for inoculant production in Argentina

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

Munich

Congreso; 10th European Nitrogen Fixation Conference; 2012

HelmohltzZentrum Munchen

In the 1980s, an intensive agricultural program to select and identify Azospirillum sp. strains able to improve productivity of wheat and corn was started by INTA-IMYZA. A. brasilense strain Az39 was selected as one of the most effective PGPR and recommended for inoculant formulation in Argentina. Numerous laboratory, greenhouse and field experiments since then have demonstrated the effectiveness of Az39 to increase growth and productivity in several crops species. In this work, we present a comprehensive analysis of the genomic features, nitrogen fixation and metabolism of Az39.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 454 Newbler v2.6 with a 19X genome coverage. 10 scaffolds were obtained. The draft genome was 7,418,177 bases in length with a mean GC content of 68.0%. Genome annotation was done using the Standard Operating Procedures for Prokaryotic annotation from ISGA and from RAST annotation server. A total of 6,696 Coding Sequences (CDS) and 82 structural RNAs were predicted. Annotation covered 489 RAST subsystems with 2,715 CDS (41%), while 2,521 (38%) were classified as hypothetical proteins. The putative nitrogen fixation and metabolism genes of Az39 [16S ribosomal RNA gene accesion number JQ844453.1] were analyzed and compared with those previously obtained for Azospirillum brasilense Sp245, Azospirillum lipoferum 4B and Azospirillum sp. strain B510. Comparative analysis was performed by the use of KEGG, RAST and INDEAR web services tools.