Complete genome resource for Pseudomonas sp. strain WP18 isolated from a disease suppressive soil

Authors: WILLIS, EMMA - Mississippi State University; STEPHEN, PHILLIPS - Mississippi State University; Jeffers, Daniel; LU, SHI-EN - Mississippi State University

Submitted to: PhytoFrontiers
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/29/2025
Publication Date: 4/30/2025
Citation: Willis, E., Stephen, P.W., Jeffers, D., Lu, S. 2025. Complete genome resource for Pseudomonas sp. strain WP18 isolated from a disease suppressive soil. PhytoFrontiers. 0:1-17. https://doi.org/10.1094/PHYTOFR-07-24-0084-A.
DOI: https://doi.org/10.1094/PHYTOFR-07-24-0084-A

Interpretive Summary: The identification of novel biocontrol organisms adds another tool for the control of plant pathogens. This study examined the effectiveness of the bacterial isolate WP18 obtained from the roots of a healthy soybean plant growing in a charcoal rot disease plot, to inhibit the growth of diverse plant pathogens. In addition, the genome was examined to better understand the mechanism responsible for disease suppression. Preliminary studies show that strain WP18 possesses antimicrobial activity against eight known plant pathogens of several crops. The bacteria was identified as a Pseudomonas species and possesses two gene regions responsible for the production of the antimicrobial compounds hydrogen cyanide and 2,4-diacetylphloroglucinol. However, genes for the production of the antimicrobial compounds phenazines, or phytotoxins were not found. The findings of this study provide a genome resource for this newly discovered putative biocontrol agent which can studied further in basic research and to examine its' effectiveness for suppressing plant diseases under field conditions.

Technical Abstract: Bacterial strain WP18 was isolated from the rhizosphere of a healthy soybean plant growing in a charcoal rot disease patch, caused by the fungal pathogen Macrophomina phaseolina. The 16S rDNA sequence analysis demonstrated the strain belongs to the genus Pseudomonas. Preliminary studies show that strain WP18 possesses antimicrobial activity against known plant pathogens. Pseudomonas sp. strain WP18 was found to have a single, circular chromosome which is 6,336,986 base pairs in size. No plasmids were detected. The genome harbors 5,669 total genes. Totally, 5,533 are considered protein-coding genes and 150 are considered pseudogenes. There are 5,583 coding sequences in the genome, which include two gene clusters encoding the antimicrobial compounds hydrogen cyanide and 2,4-diacetylphloroglucinol. However, the essential genes for production of phenazines, the type 3 secretion system or Pseudomonas phytotoxins were not found. The genome has 16 rRNAs, 66 tRNAs, and four non-coding RNAs. The findings of this study will provide a genome resource for the bacterium.