title: Overexpression of the CYP51A1 Gene and Repeated Elements are Associated with Differential Sensitivity to DMI Fungicides in Venturia inaequalis.
abstract: The involvement of overexpression of the CYP51A1 gene in Venturia inaequalis was investigated for isolates exhibiting differential sensitivity to the triazole demethylation inhibitor (DMI) fungicides myclobutanil and difenoconazole. Relative expression (RE) of the CYP51A1 gene was significantly greater (P < 0.0001) for isolates with resistance to both fungicides (MRDR phenotype) or with resistance to difenoconazole only (MSDR phenotype) compared with isolates that were resistant only to myclobutanil (MRDS phenotype) or sensitive to both fungicides (MSDS phenotype). An average of 9- and 13-fold increases in CYP51A1 RE were observed in isolates resistant to difenoconazole compared with isolates with MRDS and MSDS phenotypes, respectively. Linear regression analysis between isolate relative growth on myclobutanil-amended medium and log10 RE revealed that little to no variability in sensitivity to myclobutanil could be explained by CYP51A1 overexpression (R(2) = 0.078). To investigate CYP51A1 upstream anomalies associated with CYP51A1 overexpression or resistance to difenoconazole, Illumina sequencing was conducted for three isolates with resistance to difenoconazole and one baseline isolate. A repeated element, "EL 3,1,2", with the properties of a transcriptional enhancer was identified two to four times upstream of CYP51A1 in difenoconazole-resistant isolates but was not found in isolates with the MRDS phenotype. These results suggest that different mechanisms may govern resistance to different DMI fungicides in the triazole group.
authors: First author: Department of Plant Pathology, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River 28759; second author: Biology Department, University of Massachusetts, Life Sciences Lab N585, Amherst 01003; third author: Institut National de la Recherche Agronomique, Université de Strasbourg, UMR 1131 santé de la Vigne et Qualité du Vin, Colmar Cedex, France; and fourth author: Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Geneva, NY 14456.
authors: Sara M
authors: SM
authors: Villani
authors: First author: Department of Plant Pathology, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River 28759; second author: Biology Department, University of Massachusetts, Life Sciences Lab N585, Amherst 01003; third author: Institut National de la Recherche Agronomique, Université de Strasbourg, UMR 1131 santé de la Vigne et Qualité du Vin, Colmar Cedex, France; and fourth author: Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Geneva, NY 14456.
authors: Jon
authors: J
authors: Hulvey
authors: First author: Department of Plant Pathology, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River 28759; second author: Biology Department, University of Massachusetts, Life Sciences Lab N585, Amherst 01003; third author: Institut National de la Recherche Agronomique, Université de Strasbourg, UMR 1131 santé de la Vigne et Qualité du Vin, Colmar Cedex, France; and fourth author: Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Geneva, NY 14456.
authors: Jean-Michel
authors: JM
authors: Hily
authors: First author: Department of Plant Pathology, Mountain Horticultural Crops Research and Extension Center, North Carolina State University, Mills River 28759; second author: Biology Department, University of Massachusetts, Life Sciences Lab N585, Amherst 01003; third author: Institut National de la Recherche Agronomique, Université de Strasbourg, UMR 1131 santé de la Vigne et Qualité du Vin, Colmar Cedex, France; and fourth author: Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Geneva, NY 14456.
authors: Kerik D
authors: KD
authors: Cox
mesh_terms: D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D025141:Drug Resistance, Fungal / Q000235:genetics*; D005659:Fungicides, Industrial / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D058886:Sterol 14-Demethylase / Q000235:genetics / Q000378:metabolism*
chemical_list: D005659:Fungicides, Industrial; D058886:Sterol 14-Demethylase