Antifungal activity of Pseudomonas chlororaphis S1Bt23 and colonization of canola and tomato roots.
Citation
CHI S. I., V. PLANTE, D. CHABOT, M. HADINEZHAD, S. F. PINTO, H. BALASUNDARAM, R. XU AND J. T. TAMBONG (2019). Antifungal activity of strain S1Bt23, a novel subspecies of Pseudomonas chlororaphis, and its colonization of canola and tomato roots visualized using green fluorescent protein (gfp) transformants. 2019 Annual Meeting of the Canadian Phytopathological Society-Eastern Ontario Region. Oral presentation. Boolk of abstracts: OR07.
Résumé en langage clair
Canadian field and greenhouse crops incur significant yield losses annually due to fungal/Oomycete phytopathogens. To reduce the impact of these pathogens on crop yield, chemical pesticides are used routinely. However, these chemicals are reported to cause public health issues as well as destabilising aquatic and terrestrial ecosystems. Bacteria that produce antifungal compounds are increasingly being used as reliable alternatives. We isolated a strain that is effective at inhibiting the growth of five different plant pathogenic fungi/Oomycetes. Analysis of the genome of strain S1Bt23 reveals the presence of complete operons for antimicrobial compounds such as phenazine and pyrrolnitrin production. We conclude that the strain S1Bt23 could be a potential biocontrol agent.
Résumé
Actual title: Antifungal activity of Pseudomonas chlororaphis S1Bt23, a novel subspecies of, and its colonization of canola and tomato roots visualized using green fluorescent protein (gfp) transformants.
Canadian field and greenhouse crops incur significant yield losses annually due to fungal/Oomycete phytopathogens. To reduce the impact of these pathogens on crop yield, chemical pesticides are used routinely. However, these chemicals are reported to cause public health issues as well as destabilising aquatic and terrestrial ecosystems. Bacteria that produce antifungal compounds are increasingly being used as reliable alternatives. Pseudomonas chlororaphis is a promising species known for their production of potent antifungal compounds such as 2,4-diacetylphloroglucinol (2,4-DAPG), phenazines. P. chlororaphis strain S1Bt23 was isolated from Canadian soil, characterised by electron microscopy, 16S rRNA gene sequencing, Multi-Locus Sequence Analysis (rpoD, gyrB, and rpoB) and whole-genome analysis. In silico genome-based analysis indicated that strain S1Bt23 is an authentic novel subspecies within P. chlororaphis. The strain was tested, in vitro, for antifungal activity and found to inhibit the growth of five different plant pathogenic fungi/Oomycetes (Alternaria solani, Pythium ultimum, Pythium arrhenomanes, Rhizoctonia solani, and Sclerotinia sclerotinium). Analysis of the genome of strain S1Bt23 reveals the presence of complete operons for phenazine and pyrrolnitrin production. TLC/HPLC studies confirmed the production of phenazine and pyrrolnitrin by strain S1Bt23. Confocal microscopic studies using gfp-tagged P. chlororaphis strain S1Bt23 revealed differential root colonization patterns between canola and tomato. We conclude that P. chlororaphis strain S1Bt23 could be a potential biocontrol agent. Gene “knock-out” studies are being conducted to demonstrate the involvement of these metabolites in the antifungal activity of strain S1Bt23.