MYT3, a Myb-like transcription factor, affects fungal development and pathogenicity of Fusarium graminearum.
We previously characterized members of the Myb protein family, MYT1 and MYT2, in Fusarium graminearum. MYT1 and MYT2 are involved in female fertility and perithecium size, respectively. To expand knowledge of Myb proteins in F. graminearum, in this study, we characterized the functions of the MYT3 gene, which encodes a putative Myb-like transcription factor containing two Myb DNA-binding domains and is conserved in the subphylum Pezizomycotina of Ascomycota. MYT3 proteins were localized in nuclei during most developmental stages, suggesting the role of MYT3 as a transcriptional regulator. Deletion of MYT3 resulted in impairment of conidiation, germination, and vegetative growth compared to the wild type, whereas complementation of MYT3 restored the wild-type phenotype. Additionally, the Δmyt3 strain grew poorly on nitrogen-limited media; however, the mutant grew robustly on minimal media supplemented with ammonium. Moreover, expression level of nitrate reductase gene in the Δmyt3 strain was decreased in comparison to the wild type and complemented strain. On flowering wheat heads, the Δmyt3 strain exhibited reduced pathogenicity, which corresponded with significant reductions in trichothecene production and transcript levels of trichothecene biosynthetic genes. When the mutant was selfed, mated as a female, or mated as a male for sexual development, perithecia were not observed on the cultures, indicating that the Δmyt3 strain lost both male and female fertility. Taken together, these results demonstrate that MYT3 is required for pathogenesis and sexual development in F. graminearum, and will provide a robust foundation to establish the regulatory networks for all Myb-like proteins in F. graminearum.
Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea.
Yongsoo
Y
Kim
Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea.
Hun
H
Kim
Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea.
Hokyoung
H
Son
Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.
Gyung Ja
GJ
Choi
Eco-friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence Chemistry, Korea Research Institute of Chemical Technology, Daejeon, Republic of Korea.
Jin-Cheol
JC
Kim
Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, Republic of Korea.
Yin-Won
YW
Lee
D000595:Amino Acid Sequence; D004271:DNA, Fungal / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005670:Fusarium / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000382:microbiology; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013172:Spores, Fungal / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014255:Trichothecenes / Q000096:biosynthesis; D014908:Triticum / Q000382:microbiology; D014774:Virulence
D004271:DNA, Fungal; D005656:Fungal Proteins; D014157:Transcription Factors; D014255:Trichothecenes