title: FgVelB globally regulates sexual reproduction, mycotoxin production and pathogenicity in the cereal pathogen Fusarium graminearum.
abstract: The velvet genes are conserved in ascomycetous fungi and function as global regulators of differentiation and secondary metabolism. Here, we characterized one of the velvet genes, designated FgVelB, in the plant-pathogenic fungus Fusarium graminearum, which causes fusarium head blight in cereals and produces mycotoxins within plants. FgVelB-deleted (ΔFgVelB) strains produced fewer aerial mycelia with less pigmentation than those of the wild-type (WT) during vegetative growth. Under sexual development conditions, the ΔFgVelB strains produced no fruiting bodies but retained male fertility, and conidiation was threefold higher compared with the WT strain. Production of trichothecene and zearalenone was dramatically reduced compared with the WT strain. In addition, the ΔFgVelB strains were incapable of colonizing host plant tissues. Transcript analyses revealed that FgVelB was highly expressed during the sexual development stage, and may be regulated by a mitogen-activated protein kinase cascade. Microarray analysis showed that FgVelB affects regulatory pathways mediated by the mating-type loci and a G-protein alpha subunit, as well as primary and secondary metabolism. These results suggest that FgVelB has diverse biological functions, probably by acting as a member of a possible velvet protein complex, although identification of the FgVelB-FgVeA complex and the determination of its roles require further investigation.
authors.affiliation: Department of Applied Biology, Dong-A University, Busan 604-714, Republic of Korea.
authors.forename: Jungkwan
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Kilseon
authors.initials: K
authors.lastname: Myong
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Jung-Eun
authors.initials: JE
authors.lastname: Kim
authors.affiliation: Department of Medical Biotechnology, Soonchunhyang University, Asan 336-745, Republic of Korea.
authors.forename: Hee-Kyoung
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Medical Biotechnology, Soonchunhyang University, Asan 336-745, Republic of Korea.
authors.forename: Sung-Hwan
authors.initials: SH
authors.lastname: Yun
authors.affiliation: Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Yin-Won
authors.initials: YW
authors.lastname: Lee
mesh_terms: D002523:Edible Grain / Q000382:microbiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005670:Fusarium / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity / Q000502:physiology*; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D046228:Microarray Analysis; D025282:Mycelium / Q000254:growth & development; D009183:Mycotoxins / Q000096:biosynthesis*; D010860:Pigments, Biological / Q000378:metabolism; D010935:Plant Diseases / Q000382:microbiology*; D011995:Recombination, Genetic; D013172:Spores, Fungal / Q000254:growth & development; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis*
chemical_list: D005656:Fungal Proteins; D009183:Mycotoxins; D010860:Pigments, Biological; D037521:Virulence Factors