title: Inactivation of the global regulator LaeA in Monascus ruber results in a species-dependent response in sporulation and secondary metabolism.
abstract: The nuclear regulator LaeA has been proven to globally govern fungal development and secondary metabolism, but its function may be species-dependent, even though its amino acid sequences are well conserved in numerous fungi. Herein we identified the LaeA in Monascus ruber M7 (MrLaeA), and verified its role to mediate growth, sporulation and secondary metabolism. Results showed that the radial growth rate of the selected MrlaeA knock-out mutant (MrΔlaeA-22) was significantly faster than that of the parental strain M. ruber M7, and growth was accompanied by the formation of an abnormal colony phenotype with more abundant aerial hyphae. Interestingly, conidia production of the MrΔlaeA-22 strain was about thrice that of M. ruber M7, but ascospores were not observed in the MrΔlaeA-22 strain. Additionally, compared to M. ruber M7, MrΔlaeA-22 exhibited drastically reduced production of multiple secondary metabolites, especially those of the six well-known Monascus pigments and citrinin. Simultaneously, the selected MrlaeA complementation strain (MrΔlaeA::laeA-45) nearly recovered the capacity for sporulation and secondary metabolism observed in the parental strain. These results demonstrate that MrLaeA regulates not only secondary metabolism, but also asexual and sexual differentiation in M. ruber, but some of its regulation appears to differ from other fungi.
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China.
authors.forename: Qingpei
authors.initials: Q
authors.lastname: Liu
authors.affiliation: College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Cai
authors.affiliation: Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Ministry of Education, Wuhan 430070, Hubei Province, PR China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China.
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Shao
authors.affiliation: Institute of Quality Standard and Testing Technology for Agro-Products, Hubei Academy of Agricultural Sciences, Wuhan 430070, Hubei Province, PR China.
authors.forename: Youxiang
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Ministry of Education, Wuhan 430070, Hubei Province, PR China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China.
authors.forename: Mu
authors.initials: M
authors.lastname: Li
authors.affiliation: National Key Laboratory of Agro-Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China. Electronic address: wxh@mail.hzau.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Environment Correlative Dietology, Huazhong Agricultural University, Ministry of Education, Wuhan 430070, Hubei Province, PR China; National Key Laboratory of Agro-Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China; College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China. Electronic address: supervisor.chen@aliyun.com.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Chen
mesh_terms: D002953:Citrinin / Q000378:metabolism; D055786:Gene Knockout Techniques; D005800:Genes, Fungal; D005809:Genes, Regulator; D005816:Genetic Complementation Test; D025301:Hyphae / Q000254:growth & development; D008969:Molecular Sequence Data; D032741:Monascus / Q000235:genetics* / Q000254:growth & development*; D010860:Pigments, Biological / Q000378:metabolism; D064210:Secondary Metabolism; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal / Q000254:growth & development*
chemical_list: D010860:Pigments, Biological; D002953:Citrinin
keywords: Hyphal development; LaeA; Monascus ruber; Secondary metabolism; Sporulation