title: Resistance and resilience responses of a range of soil eukaryote and bacterial taxa to fungicide application.
abstract: The application of plant protection products has the potential to significantly affect soil microbial community structure and function. However, the extent to which soil microbial communities from different trophic levels exhibit resistance and resilience to such compounds remains poorly understood. The resistance and resilience responses of a range of microbial communities (bacteria, fungi, archaea, pseudomonads, and nematodes) to different concentrations of the strobilurin fungicide, azoxystrobin were studied. A significant concentration-dependent decrease, and subsequent recovery in soil dehydrogenase activity was recorded, but no significant impact on total microbial biomass was observed. Impacts on specific microbial communities were studied using small subunit (SSU) rRNA terminal restriction fragment length polymorphism (T-RFLP) profiling using soil DNA and RNA. The application of azoxystrobin significantly affected fungal and nematode community structure and diversity but had no impact on other communities. Community impacts were more pronounced in the RNA-derived T-RFLP profiles than in the DNA-derived profiles. qPCR confirmed that azoxystrobin application significantly reduced fungal, but not bacterial, SSU rRNA gene copy number. Azoxystrobin application reduced the prevalence of ascomycete fungi, but increased the relative abundance of zygomycetes. Azoxystrobin amendment also reduced the relative abundance of nematodes in the order Enoplia, but stimulated a large increase in the relative abundance of nematodes from the order Araeolaimida.
authors.affiliation: School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, Warwickshire CV4 7AL, UK. Electronic address: c.c.howell@warwick.ac.uk.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Howell
authors.affiliation: School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, Warwickshire CV4 7AL, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Hilton
authors.affiliation: Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK.
authors.forename: Kirk T
authors.initials: KT
authors.lastname: Semple
authors.affiliation: School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, Warwickshire CV4 7AL, UK.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Bending
mesh_terms: D000818:Animals; D001105:Archaea / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D001419:Bacteria / Q000187:drug effects* / Q000235:genetics; D018407:Bacterial Physiological Phenomena / Q000187:drug effects; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D054750:Ecotoxicology; D056890:Eukaryota / Q000187:drug effects* / Q000235:genetics / Q000502:physiology*; D020387:Food Chain; D005658:Fungi / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D005659:Fungicides, Industrial / Q000633:toxicity*; D008689:Methacrylates / Q000633:toxicity; D009348:Nematoda / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D012150:Polymorphism, Restriction Fragment Length; D011743:Pyrimidines / Q000633:toxicity; D012335:RNA, Ribosomal / Q000235:genetics; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D000073739:Strobilurins
chemical_list: D005659:Fungicides, Industrial; D008689:Methacrylates; D011743:Pyrimidines; D012335:RNA, Ribosomal; D012989:Soil Pollutants; D000073739:Strobilurins; C087670:azoxystrobin
keywords: Azoxystrobin; Resilience; Resistance; T-RFLP