Publications by authors named "T Guillemette"

The unfolded protein response (UPR) is a key component of fungal virulence. The prenylated xanthone γ-mangostin isolated from (Clusiaceae) fruit pericarp, has recently been described to inhibit this fungal adaptative pathway. Considering that (Calophyllaceae) is known for its high prenylated xanthone content, its stem bark extract was fractionated using a bioassay-guided procedure based on the cell-based anti-UPR assay.

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Discovering new solutions for crop protection is a major challenge for the next decades as a result of the ecotoxicological impact of classical fungicides, the emergence of fungicide resistances, and the consequence of climate change on pathogen distribution. Previous work on fungal mutants deficient in the unfolded protein response (UPR) supported that targeting this pathway is a promising plant disease control strategy. In particular, we showed that the UPR is involved in fungal virulence by altering cell protection against host defense compounds, such as phytoalexins and phytoanticipins.

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The transmission of seed-borne pathogens by the germinating seed is responsible for major crop diseases. The immune responses of the seed facing biotic invaders are poorly documented so far. The / patho-system was used to describe at the transcription level the responses of germinating seeds and young seedling stages to infection by the necrotrophic fungus.

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RNA interference is a mechanism of suppressing gene expression in plants, animals and fungi. This regulation mechanism involves three main enzymes, Dicers (Dcr), Argonautes (Ago) and RNA Dependent RNA Polymerases (Rdrp) allowing to produce smallRNAs. RNA interference and smallRNAs have a role in the plant-microorganisms interaction, either in a pathogenic or in a symbiotic relationships.

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The impact of the form of nitrogen (N) source (nitrate versus ammonium) on the susceptibility to Alternaria brassicicola, a necrotrophic fungus, has been examined in Arabidopsis thaliana at the rosette stage. Nitrate nutrition was found to increase fungal lesions considerably. There was a similar induction of defence gene expression following infection under both N nutritions, except for the phytoalexin deficient 3 gene, which was overexpressed with nitrate.

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