Genome sequence of the Lotus corniculatus microsymbiont Mesorhizobium loti strain R88B

Abstract

Mesorhizobium loti strain R88B was isolated in 1993 in the Rocklands range in Otago, New Zealand from a Lotus corniculatus root nodule. R88B is an aerobic, Gram-negative, non-spore-forming rod. This report reveals the genome of M. loti strain R88B contains a single scaffold of size 7,195,110 bp which encodes 6,950 protein-coding genes and 66 RNA-only encoding genes. This genome does not harbor any plasmids but contains the integrative and conjugative element ICEMl SymR7A, also known as the R7A symbiosis island, acquired by horizontal gene transfer in the field environment from M. loti strain R7A. It also contains a mobilizable genetic element ICEMl adhR88B, that encodes a likely adhesin gene which has integrated downstream of ICEMl SymR7A, and three acquired loci that together allow the utilization of the siderophore ferrichrome. This rhizobial genome is one of 100 sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.