title: The DmtA methyltransferase contributes to Aspergillus flavus conidiation, sclerotial production, aflatoxin biosynthesis and virulence.
abstract: DNA methylation is essential for epigenetic regulation of gene transcription and development in many animals, plants and fungi. We investigated whether DNA methylation plays a role in the development and secondary metabolism of Aspergillus flavus, identified the DmtA methyltransferase from A. flavus, and produced a dmtA knock-out mutant by replacing the dmtA coding sequence with the pyrG selectable marker. The A. flavus dmtA null mutant lines produced white fluffy mycelium in liquid medium, and displayed a slightly flavescent conidial pigmentation compared with the normal yellow of the wild-type strain when grown on agar. The ΔdmtA lines exhibited decreased conidiation and aflatoxin (AF) biosynthesis, compared with the wild-type line, suggesting that the DmtA knock-out affected the transcriptional level of genes in the AF cluster. In particular, sclerotia development and host colonization were altered in the dmtA null mutants. Green fluorescent protein tagging at the C-terminus of DmtA showed that DmtA localized to the nucleus and cytoplasm. DNA methylation content measurements in the dmtA mutants revealed no widespread DNA methylation in the mutants or wild-type lines. Thus, our findings suggest that DmtA, apart from being a C-5 cytosine methyltransferase in A. flavus, contributes to asexual development, aflatoxin biosynthesis, sclerotial production and virulence.
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Kunlong
authors.initials: K
authors.lastname: Yang
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Liang
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Fanlei
authors.initials: F
authors.lastname: Ran
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Yinghang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Zhenguo
authors.initials: Z
authors.lastname: Li
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Huahui
authors.initials: H
authors.lastname: Lan
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Peili
authors.initials: P
authors.lastname: Gao
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Zhenhong
authors.initials: Z
authors.lastname: Zhuang
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Xinyi
authors.initials: X
authors.lastname: Nie
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Shimuye
authors.initials: S
authors.lastname: Kalayu Yirga
authors.affiliation: Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
authors.forename: Shihua
authors.initials: S
authors.lastname: Wang
mesh_terms: D000348:Aflatoxins / Q000096:biosynthesis*; D010367:Arachis / Q000382:microbiology; D001231:Aspergillus flavus / Q000201:enzymology* / Q000472:pathogenicity / Q000502:physiology; D002467:Cell Nucleus / Q000201:enzymology; D002473:Cell Wall / Q000201:enzymology; D005656:Fungal Proteins / Q000502:physiology*; D055786:Gene Knockout Techniques; D008780:Methyltransferases / Q000502:physiology*; D009997:Osmotic Pressure; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D012639:Seeds / Q000382:microbiology; D013172:Spores, Fungal / Q000201:enzymology*; D013312:Stress, Physiological; D014774:Virulence
chemical_list: D000348:Aflatoxins; D005656:Fungal Proteins; D008780:Methyltransferases; C096006:omtA protein, Aspergillus