title: FgSsn3 kinase, a component of the mediator complex, is important for sexual reproduction and pathogenesis in Fusarium graminearum.
abstract: Fusarium graminearum is an important pathogen of wheat and barley. In addition to severe yield losses, infested grains are often contaminated with harmful mycotoxins. In this study, we characterized the functions of FgSSN3 kinase gene in different developmental and infection processes and gene regulation in F. graminearum. The FgSSN3 deletion mutant had a nutrient-dependent growth defects and abnormal conidium morphology. It was significantly reduced in DON production, TRI gene expression, and virulence. Deletion of FgSSN3 also resulted in up-regulation of HTF1 and PCS1 expression in juvenile cultures, and repression of TRI genes in DON-producing cultures. In addition, Fgssn3 was female sterile and defective in hypopodium formation and infectious growth. RNA-seq analysis showed that FgSsn3 is involved in the transcriptional regulation of a wide variety genes acting as either a repressor or activator. FgSsn3 physically interacted with C-type cyclin Cid1 and the cid1 mutant had similar phenotypes with Fgssn3, indicating that FgSsn3 and Cid1 form the CDK-cyclin pair as a component of the mediator complex in F. graminearum. Taken together, our results indicate that FgSSN3 is important for secondary metabolism, sexual reproduction, and plant infection, as a subunit of mediator complex contributing to transcriptional regulation of diverse genes.
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Shulin
authors.initials: S
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Shijie
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Chaofeng
authors.initials: C
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Huiquan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, USA.
authors.forename: Jin-Rong
authors.initials: JR
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
authors.forename: Qiaojun
authors.initials: Q
authors.lastname: Jin
mesh_terms: D017398:Alternative Splicing / Q000235:genetics; D015169:Colony Count, Microbial; D005656:Fungal Proteins / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000472:pathogenicity*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D049452:Green Fluorescent Proteins / Q000378:metabolism; D056892:Mediator Complex / Q000378:metabolism*; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation; D011494:Protein Kinases / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012098:Reproduction; D013172:Spores, Fungal / Q000254:growth & development; D013347:Subcellular Fractions / Q000378:metabolism; D014255:Trichothecenes; D014908:Triticum / Q000382:microbiology; D020798:Two-Hybrid System Techniques; D015854:Up-Regulation
chemical_list: D005656:Fungal Proteins; D056892:Mediator Complex; D050505:Mutant Proteins; D011993:Recombinant Fusion Proteins; D014255:Trichothecenes; D049452:Green Fluorescent Proteins; D011494:Protein Kinases; C007262:deoxynivalenol