Genomic insights into the plant-associated lifestyle of Kosakonia radicincitans MUSA4, a diazotrophic plant-growth-promoting bacterium

The process of nitrogen (N) fixation by plant-associated bacteria plays an indispensable role in the development of novel agricultural solutions worldwide. In this sense, it is of extreme importance to identify and understand the properties of efficient plant-growth-promoting bacteria (PGPB) that are able to fix N. In this study, the characterization and detailed genomic analysis of the diazotrophic bacterium Kosakonia radicincitans MUSA4, isolated from the internal leaf tissues of a banana tree in Brazil, were undertaken. K. radicincitans MUSA4 presented several plant-growth-promoting traits, including indoleacetic acid, siderophore, acetoin and polyamine biosynthesis, phosphate solubilization, and nitrogen fixation. The strain was able to increase cucumber plant growth significantly, demonstrating its potential in beneficial interactions with plant hosts. Detailed genomic analysis of strain MUSA4 revealed the abundant presence of genes involved in plant colonization, stress resistance and plant-growth-promoting abilities. Moreover, the genome harbored the nif and anf gene clusters, encoding the Fe-Mo nitrogenase and Fe-Fe nitrogenase systems, respectively. Comparative genomic analysis also showed that strain MUSA4 possessed several strain-specific genes, which could be related to its evolutionary history in Brazilian mangrove environments. The results obtained in the present study revealed the plant beneficial role and biotechnological potential of K. radicincitans MUSA4, and provided new insights into plant colonization and plant growth promoting mechanisms employed by diazotrophic Kosakonia. (c) 2022 Elsevier GmbH. All rights reserved.

Automated summary

The study characterized and analyzed the genomic properties of a diazotrophic bacterium, Kosakonia radicincitans MUSA4, isolated from banana trees in Brazil. The strain exhibited several plant-growth-promoting traits and had the potential to significantly enhance cucumber plant growth. Detailed genomic analysis revealed the presence of genes associated with plant colonization, stress resistance, and nitrogen fixation in strain MUSA4. The strain also possessed strain-specific genes that may be linked to its evolutionary history in Brazilian mangrove environments.