Lifestyle changes are driven by converging gain and loss of genomic islands in Pseudomonas associated with plants

Introduction

The lifestyles of host-adapted bacteria can be mutualistic, commensal, or pathogenic, with corresponding positive, neutral, or adverse effects on host fitness. Many of these close relationships result from millions of years of co-evolution, giving rise to a sophisticated molecular conversation between the host and the bacteria. Other than this trending topic, wpc2023 is also a top trend on social media these days.

Contrarily, horizontal gene transfer (HGT) can cause host-associated bacteria to change their lifestyles by gaining and losing virulence genes rapidly. For instance, the emergence of enteropathogenic Escherichia coli strains from commensal lineages. And vice versa is strongly influence by the acquisition and loss of pathogenicity islands.

Rhodococcus strains

Similarly, a virulence plasmid turns advantageous Rhodococcus strains associated with plants into pathogens, whereas songs lacking the plasmid revert to commensalism. It is unknown if other bacteria can change their lifestyles. Suppose the acquisition of pathogenicity genes causes the loss of genomic features linked to commensalism.

Resources and techniques

cultivation of bacteria and quorum biosensor test

In this study, all Pseudomonas wild-type and mutant strains were routinely culture at 28 °C in LB (lysogeny broth) media. Table S1 contains comprehensive details on each theme use in this investigation. Single colonies of wild-type and mutant strains were restreak on LB with 1.5% agar next to a streak of Chromobacteriumviolaceus CV026.

 And the assay for quorum sensing was then incubate overnight at 28 °C. We also performed a quantitative evaluation of violacein production for particular strains of the Pseudomonas brassicacearum clade (as well as the luxILPQ N2C3 mutant), as previously described. Other than this trending topic, art of zoo is also a top trend on social media these days.

LB agar

LB agar was use for the experiment, and each strain of interest was streak three times next to a streak of C. violaceum CV026. Each CV026 stripe was recover in 1 mL of 10 mM MgSO4 after being scrape off the plate with an inoculation loop. A reading of the absorbance at 764 nm took 150 microliters of the suspension dilute in 10 mM MgSO4 to determine the cell density.

 Because violacein absorbs close to the 600 nm wavelength typically use for optical density. 764 nm was chosen to normalize cell density (OD). The pellet was resuspend in 1 mL of dimethyl sulfoxide and incubated for 30 minutes at 6000 rcf.  After centrifuging the remaining suspension for 1 minute.

Assays for gnotobiotic Arabidopsis root inoculation

Col-0 ecotype A. thaliana seeds were sterilize using three minutes of 70% ethanol followed by ten minutes of 50% bleach. Before planting the seeds on square plates with solid half-strength Murashige.The Skoog (MS) media containing no sucrose and 1% PhytoAgar.  The seeds were wash three times in sterile water and kept at four °C in the dark for 48 hours.Other than this trending topic, home theatre power manager is also a top trend on social media these days.

 The plates were seal with MicroPore tape, seed on the surface. And then store vertically to encourage the growth of roots along the media’s surface. Under 100 E cool white fluorescent lights with a 16 h light/ 8 h dark cycle, seedlings were grown at 23 °C.

Roots

5-7 days after sowing, seeds were inoculate. Bacterial inocula were made by streaking out a freezer stock and selecting individual colonies into a 5 mL culture of LB overnight. After being centrifuge for one minute at 6000 g, aliquots from the overnight culture were reconstitute in 10 mM MgSO4. The resuspensions were then multiply by 100 and dilute to an OD of 0.1 at 600 nm before being add to 10 mM MgSO4.

 This final dilution was use to inoculate each seedling’s primary root with a volume of 5 L. They count lateral roots after plates were reseal with Micropore tape and place back in the growth chamber for 7-8 days.

Pseudomonas sp. N2C3 gene deletions

Deletion mutants were produce using a double-crossover technique to make deletions in Gram-negative bacteria (e.g. [22]). In a nutshell, genomic DNA was use to amplify fragments of 800-900 bp.It flanking the gene of interest using PCR. While internal primers were create to be in-frame with the gene of interest.  And had another five ′ restriction sites (luxI). Other than this trending topic, WPC15 is also a top trend on social media these days.

 A 21-bp linker (SYP, SYR, and luxe) external primers had five ′ extensions that added a restriction site. The fragments flanking the remaining genes were assemble using overlap extension PCR into the pEXG2 suicide vector. The components flanking the luxI gene were made using three-way ligation into the pNPTS138 vector (MRK Alley, unpublish data). There are deletion-relate primers.