Chong, Pablo, Essoh, Josué Ngando, Arango Isaza, Rafael E., Keizer, Paul, Stergiopoulos, Ioannis, Seidl, Michael F., Guzman, Mauricio, Sandoval, Jorge, Verweij, Paul E., Scalliet, Gabriel, Sierotzski, Helge, de Lapeyre de Bellaire, Luc, Crous, Pedro W., Carlier, Jean, Cros, Sandrine, Meijer, Harold J.G., Peralta, Esther Lilia, Kema, Gert H.J., Sub Bioinformatics, Sub Molecular Microbiology, Theoretical Biology and Bioinformatics, Molecular Microbiology, Sub Bioinformatics, Sub Molecular Microbiology, Theoretical Biology and Bioinformatics, Molecular Microbiology, Westerdijk Fungal Biodiversity Institute - Evolutionary Phytopathology, Westerdijk Fungal Biodiversity Institute, Escuela Superior Politécnica del Litoral [Guayaquil] (ESPOL), Wageningen University and Research [Wageningen] (WUR), African Center for Research on Bananas and Plantains = Centre Africain de Recherches sur Bananiers et Plantains (CARBAP), Fonctionnement écologique et gestion durable des agrosystèmes bananiers et ananas (UR GECO), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Universidad Nacional de Colombia Sede Medellín, Corporacion para Investigaciones Biologicas (CIB), University of California [Davis] (UC Davis), University of California (UC), Utrecht University [Utrecht], Corporación Bananera Nacional (CORBANA), Radboud University Medical Center [Nijmegen], Syngenta AG Suisse, Westerdijk Fungal Biodiversity Institute [Utrecht] (WI), Royal Netherlands Academy of Arts and Sciences (KNAW), Biologie et Génétique des Interactions Plante-Parasite (UMR BGPI), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Plant Health Institute of Montpellier (UMR PHIM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Université de Montpellier (UM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Ecuadorian government through the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación (SENESCYT), Ecuadorian University, Escuela Superior Politécnica del Litoral (ESPOL), Centro de Investigaciones Biotecnológicas del Ecuador (CIBE) and Syngenta AG., Wageningen University and Research (WUR) banana program, Universidad National de Colombia, sede Medellín, Dutch Dioraphte Foundation, University of California, and Westerdijk Fungal Biodiversity Insitute [Utrecht] (WI)
BACKGROUND Pseudocercospora fijiensis is the causal agent of the black leaf streak disease (BLSD) of banana. Bananas are important global export commodities and a major staple food. Their susceptibility to BLSD pushes disease management towards excessive fungicide use, largely relying on multisite inhibitors and sterol demethylation inhibitors (DMIs). These fungicides are ubiquitous in plant disease control, targeting the CYP51 enzyme. We examined sensitivity to DMIs in P. fijiensis field isolates collected from various major banana production zones in Colombia, Costa Rica, Dominican Republic, Ecuador, the Philippines, Guadalupe, Martinique and Cameroon and determined the underlying genetic reasons for the observed phenotypes. RESULTS We observed a continuous range of sensitivity towards the DMI fungicides difenoconazole, epoxiconazole and propiconazole with clear cross‐sensitivity. Sequence analyses of PfCYP51 in 266 isolates showed 28 independent amino acid substitutions, nine of which correlated with reduced sensitivity to DMIs. In addition to the mutations, we observed up to six insertions in the Pfcyp51 promoter. Such promoter insertions contain repeated elements with a palindromic core and correlate with the enhanced expression of Pfcyp51 and hence with reduced DMI sensitivity. Wild‐type isolates from unsprayed bananas fields did not contain any promoter insertions. CONCLUSION The presented data significantly contribute to understanding of the evolution and global distribution of DMI resistance mechanisms in P. fijiensis field populations and facilitate the prediction of different DMI efficacy. The overall reduced DMI sensitivity calls for the deployment of a wider range of solutions for sustainable control of this major banana disease. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., Studies on Pseudocercospora fijiensis demethylation inhibitor (DMI) sensitivity shows that Pfcyp51 modulations correlated with fungicide resistance. The importance of amino acid substitutions at positions 137, 311, 378, 379 and 458–461 is strengthened by mathematical modelling. Changes in these positions compromise the three‐dimensional structure of the protein resulting in an affinity change. The presence of repeated elements and insertions in the promotor region of Pfcyp51 was also positively correlated with resistance to DMIs. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.