title: The Y137H mutation of VvCYP51 gene confers the reduced sensitivity to tebuconazole in Villosiclava virens.
abstract: Management of rice false smut disease caused by Villosiclava virens is dependent on demethylation inhibitor (DMI) fungicides. Investigation of molecular mechanisms of resistance is therefore of upmost importance. In this study the gene encoding the target protein for DMI fungicides (VvCYP51) was cloned and investigated. The VvCYP51 gene in the resistant mutant revealed both a change from tyrosine to histidine at position 137 (Y137H) and elevated gene expression compared to the parental isolate. In order to determine which of these mechanisms was responsible for the reduced sensitivity to DMI fungicide tebuconazole, transformants expressing the mutated or the wild type VvCYP51 gene were generated. Transformants carrying the mutated gene were more resistant to tebuconazole compared to control transformants lacking the mutation, but the expression of the VvCYP51 gene was not significantly correlated with EC50 values. The wild type VvCYP51 protein exhibited stronger affinity for tebuconazole compared to the VvCYP51/Y137H in both molecular docking analysis and experimental binding assays. The UV-generated mutant as well as transformants expressing the VvCYP51/Y137H did not exhibit significant fitness penalties based on mycelial growth and spore germination, suggesting that isolates resistant to DMI fungicides based on the Y137H mutation may develop and be competitive in the field.
authors.affiliation: Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring &Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring &Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring &Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Wei-Xiao
authors.initials: WX
authors.lastname: Yin
authors.affiliation: Department of Plant Pathology, College of Agriculture and Biotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: You-Liang
authors.initials: YL
authors.lastname: Peng
authors.affiliation: Department of Agricultural and Environmental Sciences, Clemson University, Clemson, SC 29634, USA.
authors.forename: Guido
authors.initials: G
authors.lastname: Schnabel
authors.affiliation: Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring &Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jun-Bin
authors.initials: JB
authors.lastname: Huang
authors.affiliation: Department of Plant Protection, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring &Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Chao-Xi
authors.initials: CX
authors.lastname: Luo
mesh_terms: D001665:Binding Sites; D025141:Drug Resistance, Fungal / Q000187:drug effects / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005659:Fungicides, Industrial / Q000378:metabolism / Q000494:pharmacology*; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D006999:Hypocreales / Q000187:drug effects / Q000235:genetics*; D062105:Molecular Docking Simulation; D009154:Mutation; D010802:Phylogeny; D013056:Spectrophotometry, Ultraviolet; D058886:Sterol 14-Demethylase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014230:Triazoles / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D005656:Fungal Proteins; D005659:Fungicides, Industrial; D014230:Triazoles; C087114:tebuconazole; D058886:Sterol 14-Demethylase