Project name: Sinorhizobium meliloti WSM1022

Description: The study goal was to create a high quality genome sequence of WSM1022, a symbiont of Medicago truncatula that is highly efficient in nitrogen fixation.M. truncatula is a model legume and its symbiosis with rhizobia has been widely studied using the partner strain Sinorhizobium meliloti 1021. Sm1021 is still considered a model species of rhizobia but in fact it is not efficient in terms of nitrogen fixation [1] and instead is typically found as a natural partner for M.sativa (alfalfa), a relative of M.truncatula. Other strains have been characterised as being highly efficient in nitrogen fixation when interacting with M. truncatula (WSM419 and WSM1022 [1,2]) but their interaction has never been characterised at the molecular level. In other projects we have analysed the importance of strain efficiency depending on the environment/context - enabling selection of the right microbes for a particular soil, a key potential area for agricultural improvement [3,4]. Comparison of rhizobia genomes as a factor determining nitrogen fixation efficiency has been suggested in the past [5] but has not been fully investigated. Interestingly WSM1022 is the most consistent strain in providing high plant production in all soil types studied. Complete genome sequences are already available for Sm1021 and WSM419, but the WSM1022 genome was deposited previously as a draft assembly with more than 100 contigs (BioProject Accession PRJNA78233). Thus, we carried out a high quality sequencing and assembly of the WSM1022 genome.[1]Terpolilli et al (2008) New Phytol. 179:62-6.[2]Kazmierczak et al (2017). Mol Plant Microbe Interact. 30:399-409.[3]Lagunas et al (2015) J Exp Bot. 66: 2177-2186.[4]Sergaki et al (2018) Front Plant Sci. https://doi.org/10.3389/fpls.2018.01205. [5]Terpolilli et al (2012) Adv Microb Physiol. 60:325-89.

Data type: genome sequencing

Sample scope: Monoisolate

Relevance: Environmental

Release date: 2020-06-10

Last updated: 2020-06-02