title: The fungal community changes over time in developing wheat heads.
abstract: Under normal conditions, wheat is colonized by a multitude of fungi that can have beneficial or adverse effects on plant growth and yield. To study the effect of spraying wheat heads with fungicides on the fungal community from emergence to harvest we applied an amplicon sequencing approach on single wheat heads. The climatic data showed that the spring of 2014 was very dry and without precipitation in the two weeks around flowering. An initial quantitative PCR showed that the total amount of fungal DNA increased during the entire period, without significant difference between sprayed and control wheat heads. Amplicon sequencing of the internal transcribed spacer 2 (ITS2) region showed that operational taxonomic units (OTUs) identified as Sporobolomyces roseus dominated in the first weeks, whereas Alternaria infectoria OTUs dominated in the last weeks before harvest. The only observed significant difference was that the control wheat heads contained more of the powdery mildew causing Blumeria graminis f. sp. tritici OTUs compared with the sprayed wheat heads. The dry conditions around flowering most likely also had an effect on Fusarium head blight infection as Fusarium OTUs were only sporadically encountered. Analyses of secondary metabolites produced by Fusarium and Alternaria in the wheat heads confirmed the observations from the amplicon sequencing. Enniatin B was the most frequent contaminant present in four sprayed (49-538 ng/g) and three control (56-355 ng/g) wheat heads. The A. infectoria secondary metabolites infectopyrone and 4Z-infectopyrone were however consistently observed in all samples collected the last five weeks before harvest.
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Morten
authors.initials: M
authors.lastname: Hertz
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Iben Ravnborg
authors.initials: IR
authors.lastname: Jensen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Laura Østergaard
authors.initials: LØ
authors.lastname: Jensen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Søren Nøhr
authors.initials: SN
authors.lastname: Thomsen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Winde
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Morten Simonsen
authors.initials: MS
authors.lastname: Dueholm
authors.affiliation: Department of Molecular Biology and Genetics, Center for Quantitative Genetics and Genomics, Aarhus University, Blichers Allé 20, DK-8830 Tjele, Denmark.
authors.forename: Lydia Henriette
authors.initials: LH
authors.lastname: Sørensen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Rasmus Dam
authors.initials: RD
authors.lastname: Wollenberg
authors.affiliation: HOS Agronomen ApS, Gårdkrogsvej 10, DK-6780 Skærbæk, Denmark.
authors.forename: Hans Otto
authors.initials: HO
authors.lastname: Sørensen
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark.
authors.forename: Teis Esben
authors.initials: TE
authors.lastname: Sondergaard
authors.affiliation: Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, DK-9220 Aalborg Ø, Denmark; Department of Chemistry and Bioscience, Aalborg University, Niels Bohrs Vej 8, DK-6700 Esbjerg, Denmark. Electronic address: jls@bio.aau.dk.
authors.forename: Jens Laurids
authors.initials: JL
authors.lastname: Sørensen
mesh_terms: D001203:Ascomycota / Q000187:drug effects / Q000502:physiology; D005659:Fungicides, Industrial / Q000494:pharmacology*; D005670:Fusarium / Q000187:drug effects / Q000502:physiology; D064307:Microbiota / Q000187:drug effects*; D014908:Triticum / Q000382:microbiology*
chemical_list: D005659:Fungicides, Industrial
keywords: Alternaria infectoria; Amplicon sequencing; Fusarium; Mycobiome; Mycotoxins; Next generation sequencing