title: Fungicide-induced transposon movement in Monilinia fructicola.
abstract: Repeated applications of fungicides with a single mode of action are believed to select for pre-existing resistant strains in a pathogen population, while the impact of sub-lethal doses of such fungicides on sensitive members of the population is unknown. In this study, in vitro evidence is presented that continuous exposure of Monilinia fructicola mycelium to some fungicides can induce genetic change in form of transposon transposition. Three fungicide-sensitive M. fructicola isolates were exposed in 12 weekly transfers of mycelia to a dose gradient of demethylation inhibitor fungicide (DMI) SYP-Z048 and quinone outside inhibitor fungicide (QoI) azoxystrobin in solo or mixture treatments. Evidence of mutagenesis was assessed by monitoring Mftc1, a multicopy transposable element of M. fructicola, by PCR and Southern blot analysis. Movement of Mftc1 was observed following azoxystrobin and azoxystrobin plus SYP-Z048 treatments in two of the three isolates, but not in the non-fungicide-treated controls. Interestingly, the upstream promoter region of MfCYP51 was a prime target for Mftc1 transposition in these isolates. Transposition of Mftc1 was verified by Southern blot in two of three isolates from another, similar experiment following prolonged, sublethal azoxystrobin exposure, although in these isolates movement of Mftc1 in the upstream MfCYP51 promoter region was not observed. More research is warranted to determine whether fungicide-induced mutagenesis may also happen under field conditions.
authors.affiliation: Key Laboratory of Biopesticide and Chemical Biology, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, China; Department of Plant Pathology, China Agricultural University, Beijing, China.
authors.forename: Fengping
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Plant Pathology, University of Nebraska, Lincoln, NE, USA.
authors.forename: Sydney E
authors.initials: SE
authors.lastname: Everhart
authors.affiliation: School of Agricultural and Environmental Sciences, Clemson University, Clemson, SC, USA.
authors.forename: P Karen
authors.initials: PK
authors.lastname: Bryson
authors.affiliation: College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Chaoxi
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Plant Pathology, China Agricultural University, Beijing, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Song
authors.affiliation: Department of Plant Pathology, China Agricultural University, Beijing, China. Electronic address: seedling@cau.edu.cn.
authors.forename: Xili
authors.initials: X
authors.lastname: Liu
authors.affiliation: School of Agricultural and Environmental Sciences, Clemson University, Clemson, SC, USA. Electronic address: schnabe@clemson.edu.
authors.forename: Guido
authors.initials: G
authors.lastname: Schnabel
mesh_terms: D001203:Ascomycota / Q000187:drug effects* / Q000235:genetics; D004251:DNA Transposable Elements / Q000187:drug effects* / Q000235:genetics; D005659:Fungicides, Industrial / Q000494:pharmacology*; D007555:Isoxazoles / Q000494:pharmacology*; D008689:Methacrylates / Q000494:pharmacology; D016296:Mutagenesis / Q000187:drug effects; D025282:Mycelium / Q000187:drug effects; D010935:Plant Diseases / Q000382:microbiology*; D011725:Pyridines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology; D000073739:Strobilurins
chemical_list: D004251:DNA Transposable Elements; D005659:Fungicides, Industrial; D007555:Isoxazoles; D008689:Methacrylates; D011725:Pyridines; D011743:Pyrimidines; C578054:SYP-Z048; D000073739:Strobilurins; C087670:azoxystrobin
keywords: Brown rot; Mutagenesis; QoI fungicide; Transposon movement