Analysis of the CYP51 gene and encoded protein in propiconazole‐resistant isolates of Mycosphaerella fijiensis |
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| Authors: | Gloria P Cañas‐Gutiérrez Mónica J Angarita‐Velásquez Juan M Restrepo‐Flórez Paola Rodríguez Claudia X Moreno Rafael Arango |
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| Institution: | 1. Unidad de Biotecnología Vegetal, Corporación para Investigaciones Biológicas UNALMED‐CIB, Carrera 72 A # 78 B‐141, Medellín, Colombia;2. Centro de Investigaciones del Banano, Cenibanano, AUGURA, Calle 3S 41‐65, Medellín, Colombia;3. Escuela de Biociencias, Facultad de Ciencias, Universidad Nacional de Colombia, Autopista Norte, Carrera 64 Calle 65, Medellín, Colombia |
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| Abstract: | BACKGROUND: Mycosphaerella fijiensis Morelet causes black sigatoka, the most important disease in bananas and plantains. Disease control is mainly through the application of systemic fungicides, including sterol demethylation inhibitors (DMIs). Their intensive use has favoured the appearance of resistant strains. However, no studies have been published on the possible resistance mechanisms. RESULTS: In this work, the CYP51 gene was isolated and sequenced in 11 M. fijiensis strains that had shown different degrees of in vitro sensitivity to propiconazole, one of the most widely used DMI fungicides. Six mutations that could be related to the loss in sensitivity to this fungicide were found: Y136F, A313G, Y461D, Y463D, Y463H and Y463N. The mutations were analysed using a homology model of the protein that was constructed from the crystallographic structure of Mycobacterium tuberculosis (Zoff.) Lehmann & Neumann. Additionally, gene expression was determined in 13 M. fijiensis strains through quantitative analysis of products obtained by RT‐PCR. CONCLUSION: Several changes in the sequence of the gene encoding sterol 14α‐demethylase were found that have been described in other fungi as being correlated with resistance to azole fungicides. No correlation was found between gene expression and propiconazole resistance. Copyright © 2009 Society of Chemical Industry |
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| Keywords: | black sigatoka Mycosphaerella fijiensis propiconazole DMI fungicides azole fungicide resistance |
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