title: Transcriptional control of fungal cell cycle and cellular events by Fkh2, a forkhead transcription factor in an insect pathogen.
abstract: Transcriptional control of the cell cycle by forkhead (Fkh) transcription factors is likely associated with fungal adaptation to host and environment. Here we show that Fkh2, an ortholog of yeast Fkh1/2, orchestrates cell cycle and many cellular events of Beauveria bassiana, a filamentous fungal insect pathogen. Deletion of Fkh2 in B. bassiana resulted in dramatic down-regulation of the cyclin-B gene cluster and hence altered cell cycle (longer G2/M and S, but shorter G0/G1, phases) in unicellular blastospores. Consequently, ΔFkh2 produced twice as many, but smaller, blastospores than wild-type under submerged conditions, and formed denser septa and shorter/broader cells in aberrantly branched hyphae. In these hyphae, clustered genes required for septation and conidiation were remarkedly up-regulated, followed by higher yield and slower germination of aerial conidia. Moreover, ΔFkh2 displayed attenuated virulence and decreased tolerance to chemical and environmental stresses, accompanied with altered transcripts and activities of phenotype-influencing proteins or enzymes. All the changes in ΔFkh2 were restored by Fkh2 complementation. All together, Fkh2-dependent transcriptional control is vital for the adaptation of B. bassiana to diverse habitats of host insects and hence contributes to its biological control potential against arthropod pests.
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors.forename: Juan-Juan
authors.initials: JJ
authors.lastname: Wang
authors.affiliation: 1] Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China [2] School of bioengineering, Qilu University of Technology, Jinan, Shandong, 250353, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors.forename: Sheng-Hua
authors.initials: SH
authors.lastname: Ying
authors.affiliation: Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
authors.forename: Ming-Guang
authors.initials: MG
authors.lastname: Feng
mesh_terms: D000818:Animals; D052982:Beauveria / Q000166:cytology* / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D002453:Cell Cycle / Q000235:genetics*; D048429:Cell Size / Q000187:drug effects; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005659:Fungicides, Industrial / Q000494:pharmacology; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects; D025301:Hyphae / Q000187:drug effects / Q000502:physiology; D007313:Insecta / Q000382:microbiology*; D009995:Osmosis / Q000187:drug effects; D016877:Oxidants / Q000494:pharmacology; D010641:Phenotype; D013172:Spores, Fungal / Q000187:drug effects / Q000502:physiology; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014158:Transcription, Genetic / Q000187:drug effects; D014774:Virulence / Q000187:drug effects / Q000235:genetics
chemical_list: D051858:Forkhead Transcription Factors; D005656:Fungal Proteins; D005659:Fungicides, Industrial; D016877:Oxidants