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421 results on '"Beaulieu, Carole"'

12. Identification and genomic characterization of Pseudomonas spp. displaying biocontrol activity against Sclerotinia sclerotiorum in lettuce.

Author

Albert, Daphné, Zboralski, Antoine, Ciotola, Marie, Cadieux, Mélanie, Biessy, Adrien, Blom, Jochen, Beaulieu, Carole, and Filion, Martin

Subjects
SCLEROTINIA sclerotiorum, PSEUDOMONAS, BIOLOGICAL pest control agents, PSEUDOMONAS fluorescens, LETTUCE, LETTUCE growing, WHOLE genome sequencing, FUNGICIDE resistance, RHIZOSPHERE
Abstract

Lettuce is an economically major leafy vegetable that is affected by numerous diseases. One of the most devastating diseases of lettuce is white mold caused by Sclerotinia sclerotiorum. Control methods for this fungus are limited due to the development of genetic resistance to commonly used fungicides, the large number of hosts and the long-term survival of sclerotia in soil. To elaborate a new and more sustainable approach to contain this pathogen, 1,210 Pseudomonas strains previously isolated from agricultural soils in Canada were screened for their antagonistic activity against S. sclerotiorum. Nine Pseudomonas strains showed strong in vitro inhibition in dual-culture confrontational assays. Whole genome sequencing of these strains revealed their affiliation with four phylogenomic subgroups within the Pseudomonas fluorescens group, namely Pseudomonas corrugata, Pseudomonas asplenii, Pseudomonas mandelii, and Pseudomonas protegens. The antagonistic strains harbor several genes and gene clusters involved in the production of secondary metabolites, including mycin-type and peptin-type lipopeptides, and antibiotics such as brabantamide, which may be involved in the inhibitory activity observed against S. sclerotiorum. Three strains also demonstrated significant in planta biocontrol abilities against the pathogen when either inoculated on lettuce leaves or in the growing substrate of lettuce plants grown in pots. They however did not impact S. sclerotiorum populations in the rhizosphere, suggesting that they protect lettuce plants by altering the fitness and the virulence of the pathogen rather than by directly impeding its growth. These results mark a step forward in the development of biocontrol products against S. sclerotiorum. [ABSTRACT FROM AUTHOR]

Published
2024
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18. The combination of nutraceuticals and functional feeds as additives modulates gut microbiota and blood markers associated with immune response and health in weanling piglets

Author

Lo Verso, Luca, primary, Talbot, Guylaine, additional, Morissette, Bruno, additional, Guay, Frédéric, additional, Matte, J Jacques, additional, Farmer, Chantal, additional, Gong, Joshua, additional, Wang, Qi, additional, Bissonnette, Nathalie, additional, Beaulieu, Carole, additional, and Lessard, Martin, additional

Published
2020
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29. Increased abundance of patatins, lipoxygenase and miraculins in a thaxtomin A‐habituated potato Russet Burbank somaclone with enhanced resistance to common scab.

Author

Isayenka, Iauhenia, Duque‐Yate, Juan, Goulet, Marie‐Claire, Michaud, Dominique, Beaulieu, Carole, and Beaudoin, Nathalie

Subjects
LIPID metabolism, POTATOES, PROTEASE inhibitors, TUBERS, STREPTOMYCES
Abstract

Potato common scab caused by the actinobacterium Streptomyces scabiei is characterized by the formation of corky lesions on tubers that reduce their marketability. Management of common scab is very complex and often ineffective under various environmental conditions. Using potato varieties that are more resistant to common scab remains one of the most efficient strategies to control this disease. However, very little is known about the factors associated with resistance to common scab. Somaclone RB9 regenerated from thaxtomin A‐habituated potato Russet Burbank calli produced tubers more resistant to common scab than the original variety. Comparison of the RB9 tuber proteome with that of Russet Burbank using label‐free quantitative proteomic analysis revealed changes in the accumulation of defence‐related proteins from the patatin and lipoxygenase (LOX) families, which are involved in the metabolism of lipids, and of two miraculins of the Kunitz‐type protease inhibitors family. The implication of LOX during common scab infection was studied using synchronized minitubers developed from leaf‐bud cuttings. S. scabiei infection stimulated the accumulation of LOX in both Russet Burbank and RB9 minitubers, but this accumulation was intensified in RB9 minitubers. Infection also increased LOX activity in Russet Burbank and RB9 minitubers. However, LOX activity measured in noninfected RB9 minitubers was similar to that of infected Russet Burbank minitubers, indicating endogenous activation of LOX activity in RB9 minitubers. We discuss how increased LOX abundance and activity in the somaclone RB9 may contribute to improving tuber defence against common scab. [ABSTRACT FROM AUTHOR]

Published
2023
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37. A terD domain-encoding gene (SCO2368) iss involved in calcium homeostasis and participates in calcium regulation of a DosR-like regulon in Streptomyces coelicolor

Author

Daigle, Francois, Lerat, Sylvain, Bucca, Giselda, Sanssouci, Edith, Smith, Colin P., Malouin, Francois, and Beaulieu, Carole

Subjects
Streptomyces -- Genetic aspects, Streptomyces -- Physiological aspects, Gene mutations -- Analysis, Nucleotide sequence -- Analysis, Biological sciences
Abstract

Although Streptomyces coelicolor is not resistant to tellurite, it possesses several TerD domain-encoding (tdd) genes of unknown function. To elucidate the function of tdd8, the transcriptomes of S. coelicolor strain M145 and of a tdd8 deletion mutant derivative (the ?tdd8 strain) were compared. Several orthologs of Mycobacterium tuberculosis genes involved in dormancy survival were upregulated in the deletion mutant at the visual onset of prodiginine production. These genes are organized in a putative redox stress response cluster comprising two large loci. A binding motif similar to the dormancy survival regulator (DosR) binding site of M. tuberculosis has been identified in the upstream sequences of most genes in these loci. A predicted role for these genes in the redox stress response is supported by the low NAD+/NADH ratio in the ?tdd8 strain. This S. coelicolor gene cluster was shown to be induced by hypoxia and NO stress. While the tdd8 deletion mutant (the ?tdd8 strain) was unable to maintain calcium homeostasis in a calcium-depleted medium, the addition of Ca2+ in ?tdd8 culture medium reduced the expression of several genes of the redox stress response cluster. The results shown in this work are consistent with Tdd8 playing a significant role in calcium homeostasis and redox stress adaptation.

Published
2015

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