Phenazines are involved in the antagonism of a novel subspecies of Pseudomonas chlororaphis strain S1Bt23 against Pythium ultimum.

Autor: Chi SI; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada.; Canadian Blood Service, Ottawa, ON, K1G 4J5, Canada., Akuma M; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada.; University of Ottawa, Ottawa, ON, K1N 6N5, Canada., Xu R; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada., Plante V; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada., Hadinezhad M; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada., Tambong JT; Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON, K1A 0C6, Canada. james.tambong@agr.gc.ca.; Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada. james.tambong@agr.gc.ca.
Jazyk: angličtina
Zdroj: Scientific reports [Sci Rep] 2024 Sep 03; Vol. 14 (1), pp. 20517. Date of Electronic Publication: 2024 Sep 03.
DOI: 10.1038/s41598-024-71418-y
Abstrakt: Long-term use of chemical fungicides to control plant diseases caused by fungi and oomycetes has led to pathogen resistance and negative impacts on public health and environment. There is a global search for eco-friendly methods and antagonistic bacteria are emerging as alternatives. We isolated a potent antagonistic bacterial strain (S1Bt23) from woodland soil in Québec, Canada. Taxonomic characterization by 16S rRNA, multi-locus sequence analysis, pairwise whole-genome comparisons, phylogenomics and phenotypic data identified strain S1Bt23 as a novel subspecies within Pseudomonas chlororaphis. In dual culture studies, strain S1Bt23 exhibited potent mycelial growth inhibition (60.2-66.7%) against Pythium ultimum. Furthermore, strain S1Bt23 was able to significantly bioprotect potato tuber slices from the development of necrosis inducible by P. ultimum. Annotations of the whole genome sequence of S1Bt23 revealed the presence of an arsenal of secondary metabolites including the complete phenazine biosynthetic cluster (phzABCDEFG). Thin-layer (TLC) and high-performance liquid (HPLC) chromatographic analyses of S1Bt23 extracts confirmed the production of phenazines, potent antifungal compounds. CRISPR/Cas9-mediated deletion of phzB (S1Bt23ΔphzB) or phzF (S1Bt23ΔphzF) gene abrogated phenazine production based on TLC and HPLC analyses. Also, S1Bt23ΔphzB and S1Bt23ΔphzF mutants lost antagonistic activity and bioprotection ability of potato tubers against P. ultimum. This demonstrated that phenazines are involved in the antagonistic activity of S1Bt23 against P. ultimum. Finally, based on genotypic and phenotypic data, we taxonomically conclude that S1Bt23 represents a novel subspecies for which the name Pseudomonas chlororaphis subsp. phenazini is proposed.
(© 2024. Crown.)
Databáze: MEDLINE
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