Complete genome sequence of endophyte Bacillus flexus KLBMP 4941 reveals its plant growth promotion mechanism and genetic basis for salt tolerance

Abstract

Bacillus flexus KLBMP 4941 is a halotolerant endophyte isolated from the halophyte Limonium sinense. This strain can improve host seedling growth under salt stress conditions. We here report the complete genome information of endophyte KLBMP 4941. It has a circular chromosome and two plasmids for a total genome 4,104,242 bp in size with a G+C content of 38.09%. Genes related to plant growth promotion (PGP), such as those associated with nitrogen fixation, siderophore, spermidine, and acetoin synthesis were found in the KLBMP 4941 genome. Some genes responsible for high salinity tolerance, like genes associated with the Na+/H+ antiporter, glycine betaine transporter, and betaine-aldehyde dehydrogenase were also found in the KLBMP 4941 genome. The genome analysis will provide better understanding of the mechanisms underlying the promotion of plant growth in strain KLBMP 4941 under salt stress conditions and its ability to adapt to coastal salt marsh habitats, and provide a basis for its further biotechnological applications in agriculture.