INFERRING THE ROLE OF THE METABOLISM OF POLYAMINES IN THE PHYTOPATHOGENIC BACTERIA PSEUDOMONAS SYRINGAE: A META-ANALYSIS APPROACH

SOLMI L.; ROSLI H.G.; POMBO M.; STALDER S.; ROSSI F.R.; ROMERO M.; RUIZ O.A.; GARRIZ, A.

FRONTIERS IN MICROBIOLOGY

Frontiers Editorial Office

Lugar: Lausanne; Año: 2022 vol. 13

1664-302X

Our study showed that bacterial polyamine biosynthesis is repressed 48 hai, which is also associated to the induction in the expression of polyamine transporters and catabolic genes. A similar scenario is observed in later stages of pathogenic interactions established by other bacterial species. For instance, Xanthomonas axonopodis pv. glycines reduces the expression of speD but up-regulates other polyamine biosynthetic and transport genes after 72 hai in soybean (CHATNAPARAT et al. 2016), whereas polyamine synthesis was repressed in Xanthomonas oryzae pv. oryzae after 5 days while polyamine transport was activated (LEE et al. 2017). Importantly, hierarchical clustering of co-expressed gene analysis demonstrated that transcription profiles from samples taken 48 hai are grouped with those obtained from cells growing in vitro under low nitrogen conditions or in minimal medium, as well as in experiments using primed plants (pre-infiltrated with flg22) or the D36E strain. Based in this, it is reasonable to conclude that bacteria are facing more restrictive conditions at this stage. Besides, the induction of some of the polyamine metabolic genes at 48 hai is correlated with the induction of the T3SS. This observation supports the idea that the modulation of specific genes from the metabolism of polyamines, but not all, would be coordinated with the induction of virulence mechanisms. More work is needed to understand the regulatory mechanisms acting on the expression of different genes from the metabolism of these compounds throughout the infection and their impact on polyamine homeostasis.Altogether, these findings contribute to the hypothesis that polyamine synthesis in phytopathogenic Pseudomonas species is important during the early periods of plant invasion but are repressed in later stages with the consequent induction of transport systems (Figure 6). This metabolic shift enables the survival of cells in the plant environment. Whether this behaviour could be extrapolated to other bacterial species should be evaluated with the generation of specific mutant strains perturbed in the different branches of the polyamine metabolism.