Transcriptome and proteome profiles of the diazotroph Nitrospirillum amazonense strain CBAmC in response to the sugarcane apoplast fluid

The diazotrophic CBAmC strain of Nitrospirillum amazonense has been reported to promote growth of sugarcane variety RB867515 when inoculated under field conditions in a consortium with four other nitrogen-fixing bacteria. The present work had the objective of accessing the influence of the sugarcane apoplast fluid from variety RB867515 on the global transcriptomic and proteomic profiles of CBAmC strain cultured in vitro. The comparative analysis between the transcriptome and proteome profiles showed strong consistency between the results of the two approaches. Data analysis revealed that expression levels of transcripts and proteins related to cell motility and signal transduction, among other functions, were strongly downregulated in the presence of the apoplast fluid. In contrast, transcripts and proteins were upregulated for functional categories including chaperones, iron homeostasis and multidrug efflux transporters. In conclusion, the results showed that the metabolic state of N. amazonense during cultivation in the presence of the apoplast fluid is directed to functions capable of supporting adaptation to the complex environment of the sugarcane apoplast.