Cloning of the CYP51 gene from the eyespot pathogen Tapesia yallundae indicates that resistance to the DMI fungicide prochloraz is not related to sequence changes in the gene encoding the target site enzyme.
Resistance to sterol 14 alpha-demethylase inhibitor (DMI) fungicides has been correlated with mutations in the CYP51 gene encoding the target enzyme eburicol 14 alpha-demethylase. CYP51 was isolated from the eyespot pathogen Tapesia yallundae revealing a predicted 526-amino acid product exhibiting homology to other fungal CYP51s. CYP51 was sequenced from four field isolates sensitive or resistant to the DMI fungicide prochloraz and partially sequenced from two further isolates and eight progeny from a cross between prochloraz-sensitive and -resistant parents. Two alleles of the gene were detected termed CYP51-1 and CYP51-2. No correlation was found between sequence change and fungicide sensitivity. Therefore prochloraz resistance involved a mechanism other than mutation in the target site gene.
Wood
H M
HM
School of Biological Sciences, University of Nottingham, University Park, UK.
Dickinson
M J
MJ
Lucas
J A
JA
Dyer
P S
PS
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000187:drug effects* / Q000235:genetics; D001483:Base Sequence; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics / Q000302:isolation & purification; D004352:Drug Resistance, Microbial / Q000235:genetics; D002523:Edible Grain / Q000382:microbiology; D005656:Fungal Proteins / Q000235:genetics; D005659:Fungicides, Industrial / Q000494:pharmacology*; D018628:Gene Dosage; D005800:Genes, Fungal; D007093:Imidazoles / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010088:Oxidoreductases / Q000032:analysis / Q000235:genetics*; D010935:Plant Diseases / Q000382:microbiology; D058886:Sterol 14-Demethylase
D004271:DNA, Fungal; D005656:Fungal Proteins; D005659:Fungicides, Industrial; D007093:Imidazoles; D003577:Cytochrome P-450 Enzyme System; C045362:prochloraz; D010088:Oxidoreductases; D058886:Sterol 14-Demethylase