The Periplasmic Oxidoreductase DsbA Is Required for Virulence of the Phytopathogen Dickeya solani

Abstract

In bacteria, the DsbA oxidoreductase is a crucial factor responsible for the introduction of disulfide bonds to extracytoplasmic proteins, which include important virulence factors. A lack of proper disulfide bonds frequently leads to instability and/or loss of protein function; therefore, improper disulfide bonding may lead to avirulent phenotypes. The importance of the DsbA function in phytopathogens has not been extensively studied yet. Dickeya solani is a bacterium from the Soft Rot Pectobacteriaceae family which is responsible for very high economic losses mainly in potato. In this work, we constructed a D. solani dsbA mutant and demonstrated that a lack of DsbA caused a loss of virulence. The mutant bacteria showed lower activities of secreted virulence determinants and were unable to develop disease symptoms in a potato plant. The SWATH-MS-based proteomic analysis revealed that the dsbA mutation led to multifaceted effects in the D. solani cells, including not only lower levels of secreted virulence factors, but also the induction of stress responses. Finally, the outer membrane barrier seemed to be disturbed by the mutation. Our results clearly demonstrate that the function played by the DsbA oxidoreductase is crucial for D. solani virulence, and a lack of DsbA significantly disturbs cellular physiology.

Resistance of Dickeya solani strain IPO 2222 to lytic bacteriophage ΦD5 results in fitness tradeoffs for the bacterium during infection

“…Permeability of cellular outer membranes was assessed by the degree of cell lysis observed following exposure of bacteria to sodium dodecyl sulphate (SDS) 117 . Briefly, cells were grown in TSB (WT strain) or in TSB supplemented with 50 μg mL −1 neomycin (Tn5 mutants) for 16 h at 28 °C with shaking.…”

Editorial: Genome-Wide Analyses of Pectobacterium and Dickeya Species

“…The T1SS, T2SS, T6SS, some PCWDEs and proteases, the ECA cluster, achromobactin, flagellar genes, single virulence locus, the pilW and pilABC genes, Flp/Tad, carotovoricin, DsbA oxidoreductase, and the majority of virulence regulators were anticipated critical genes/gene clusters for all Pectobacterium species, while T3SS, T4SS, T5SS, phytotoxins, type IV pilus, capsular polysaccharide, lipopolysaccharides, exopolysaccharides, iron uptake systems, phenazine, carbapenem, and colicin-like bacteriocins were observed in some species. Differences among antimicrobial compounds and toxin and antitoxin systems surrounding the CRISPR-Cas systems were observed in others (Glasner et al, 2008;Charkowski et al, 2012;Arizala and Arif, 2019;Przepiora et al, 2022).…”

Resistance of Dickeya solani strain IPO 2222 to lytic bacteriophage vB_Dsol_D5 (ΦD5) results in fitness tradeoffs for the bacterium during infection

“…Permeability of the bacterial outer membrane was assessed by a degree of cell lysis observed during the incubation of bacteria in the presence of sodium dodecyl sulphate (SDS) (Przepiora et al, 2022). Briefly, D. solani WT and D. solani phage-resistant Tn5 mutants were grown in TSB (WT strain) or in TSB supplemented with 50 μg mL -1 neomycin (Tn5 mutants) for 16 h at 28 °C with shaking.…”

“…Permeability of the bacterial outer membrane was assessed by a degree of cell lysis observed during the incubation of bacteria in the presence of sodium dodecyl sulphate (SDS) (Przepiora et al, 2022).…”