Genomic and phenotypic analyses of Pseudomonas psychrotolerans PRS08-11306 reveal a turnerbactin biosynthesis gene cluster that contributes to nitrogen fixation

Abstract

Plant-microbe interactions can provide agronomic benefits, such as enhancing nutrient uptake and providing fixed nitrogen. The Pseudomonas psychrotolerans strain PRS08-11306 was isolated from rice seeds and can enhance plant growth. Here, we analyzed the P. psychrotolerans genome, which is ∼5Mb, with 4389 coding sequences, 77 tRNAs, and 7 rRNAs. Genome analysis identified a cluster of turnerbactin biosynthetic genes, which are responsible for the production of a catecholate siderophore and contribute to nitrogen fixation for the host. Analysis of the transcription factor mutant ΔrpoS, which does not express this gene cluster, confirmed the relationship between the gene cluster and siderophore production. The nitrogen fixation characteristics of the cluster were confirmed in a plant growth-promoting experiment. The annotated full genome sequence of this strain sheds light on the role of P. psychrotolerans PRS08-11306 as a plant beneficial bacterium.

Keywords: Nitrogen fixation; PacBio; Pseudomonas psychrotolerans; Siderophore; Turnerbactin.