EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
EFS12- Book of abstracts - Contact
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SESSION 1: FUSARIUM – GENETICS, GENOMICS AND SYSTEMS BIOLOGY<br />
P2 - Genome-wide transcriptional response to<br />
ambient pH and Pac1 regulatory factor in Fusarium<br />
graminearum<br />
J. Merhej 1 , N. Ponts 1 , F. Richard-Forget 1 , C. Barreau 1,2<br />
1 INRA, UR1264 MycSA, 71 Avenue Edouard Bourlaux, CS20032, 33883 Villenave d'Ornon-France;<br />
2 CNRS, UR1264 MycSA, 71 Avenue Edouard Bourlaux, 33883 Villenave d'Ornon-France<br />
E-mail: cbarreau@bordeaux.inra.fr<br />
The pathogenic fungus Fusarium graminearum produces type B trichothecene<br />
mycotoxins during cereal plants infection. Trichothecenes accumulate in cereal<br />
grains and represent a threat for health. Expression studies <strong>of</strong> the Tri genes<br />
implicated in trichothecene biosynthesis have demonstrated that acidic<br />
extracellular pH is a determinant inducer. Actually, it has been shown that the<br />
FgPac1 pH regulatory factor negatively regulates the expression <strong>of</strong> Tri genes<br />
under neutral or basic pHs. Beside their role in regulating secondary metabolites<br />
in fungi, Pac transcription factors are known to regulate various classes <strong>of</strong> genes,<br />
especially the genes whose roles involve communication with the environment. In<br />
this study, a genome-wide transcriptional analysis conducted in two different pH<br />
conditions using a strain deleted for FgPac1 and a strain expressing a<br />
constitutively active form <strong>of</strong> FgPac1was carried out to investigate the global<br />
regulation by the pH in F. graminearum. The data obtained identified a set <strong>of</strong><br />
genes related to various functions whose expression is affected by the change in<br />
pH. Our results also point toward a potential role <strong>of</strong> a regulation by calcium in<br />
response to the ambient pH and identified a γ-aminobutyric acid (GABA) shunt<br />
activated in response to acidic pH. Finally, a clustering approach followed by cisregulatory<br />
motifs search highlights the presence <strong>of</strong> complex stress-response<br />
regulatory circuits impacted by the change in external pH.<br />
Keywords: Fusarium, pH, Pac1, microarrays<br />
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