Abstract
Pseudomonas syringae is a phytopathogenic model bacterium that is used worldwide to study plant–bacteria interactions and biofilm formation in association with a plant host. Within this species, the syringae pathovar is the most studied due to its wide host range, affecting both, woody and herbaceous plants. In particular, Pseudomonas syringae pv. syringae (Pss) has been previously described as the causal agent of bacterial apical necrosis on mango trees. Pss exhibits major epiphytic traits and virulence factors that improve its epiphytic survival and pathogenicity in mango trees. The cellulose exopolysaccharide has been described as a key component in the development of the biofilm lifestyle of the P. syringae pv. syringae UMAF0158 strain (PssUMAF0158). PssUMAF0158 contains two additional genomic regions that putatively encode for exopolysaccharides such as alginate and a Psl-like polysaccharide. To date, the Psl polysaccharide has only been studied in Pseudomonas aeruginosa, in which it plays an important role during biofilm development. However, its function in plant-associated bacteria is still unknown. To understand how these exopolysaccharides contribute to the biofilm matrix of PssUMAF0158, knockout mutants of genes encoding these putative exopolysaccharides were constructed. Flow-cell chamber experiments revealed that cellulose and the Psl-like polysaccharide constitute a basic scaffold for biofilm architecture in this bacterium. Curiously, the Psl-like polysaccharide of PssUMAF0158 plays a role in virulence similar to what has been described for cellulose. Finally, the impaired swarming motility of the Psl-like exopolysaccharide mutant suggests that this exopolysaccharide may play a role in the motility of PssUMAF0158 over the mango plant surface.
Highlights
Pseudomonas syringae is a model bacterium for the study of plant–microbial interactions, as it causes diseases in woody and herbaceous plants worldwide
Cellulose is a polymer composed of β-D-glucose units that constitutes one of the main components of the biofilm matrix produced by many bacteria[23,24,25,26], and its biosynthesis has proven to be important for biofilm formation by Pss[9,27]
Adhesion experiments were performed on Bioinformatic analysis revealed that alginate- and Psl-like exopolysaccharides encoding clusters were present in the Pseudomonas syringae pv. syringae UMAF0158 genome
Summary
Pseudomonas syringae is a model bacterium for the study of plant–microbial interactions, as it causes diseases in woody and herbaceous plants worldwide. Syringae (Pss) UMAF0158 strain (PssUMAF0158) is a mango tree pathogen that is considered a model for the study of the transition between the epiphytic and pathogenic lifestyles depending on environmental conditions[5]. P. syringae produces a number of biofilm matrix polysaccharides, including alginate, levan and cellulose[9,10,11,12,13,14]. Several studies have shown that alginate plays a role in the epiphytic fitness and virulence in some P. syringae strains[7,20], as well as in biofilm structure, antibiotic resistance and protection against the human immune system in mucoid strains of P. aeruginosa[19,21,22]. Cellulose is a polymer composed of β-D-glucose units that constitutes one of the main components of the biofilm matrix produced by many bacteria[23,24,25,26], and its biosynthesis has proven to be important for biofilm formation by Pss[9,27]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
