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Hou X, Liu L, Xu D, Lai D, Zhou L. Involvement of LaeA and Velvet Proteins in Regulating the Production of Mycotoxins and Other Fungal Secondary Metabolites. J Fungi (Basel) 2024; 10:561. [PMID: 39194887 DOI: 10.3390/jof10080561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2024] [Revised: 07/30/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
Fungi are rich sources of secondary metabolites of agrochemical, pharmaceutical, and food importance, such as mycotoxins, antibiotics, and antitumor agents. Secondary metabolites play vital roles in fungal pathogenesis, growth and development, oxidative status modulation, and adaptation/resistance to various environmental stresses. LaeA contains an S-adenosylmethionine binding site and displays methyltransferase activity. The members of velvet proteins include VeA, VelB, VelC, VelD and VosA for each member with a velvet domain. LaeA and velvet proteins can form multimeric complexes such as VosA-VelB and VelB-VeA-LaeA. They belong to global regulators and are mainly impacted by light. One of their most important functions is to regulate gene expressions that are responsible for secondary metabolite biosynthesis. The aim of this mini-review is to represent the newest cognition of the biosynthetic regulation of mycotoxins and other fungal secondary metabolites by LaeA and velvet proteins. In most cases, LaeA and velvet proteins positively regulate production of fungal secondary metabolites. The regulated fungal species mainly belong to the toxigenic fungi from the genera of Alternaria, Aspergillus, Botrytis, Fusarium, Magnaporthe, Monascus, and Penicillium for the production of mycotoxins. We can control secondary metabolite production to inhibit the production of harmful mycotoxins while promoting the production of useful metabolites by global regulation of LaeA and velvet proteins in fungi. Furthermore, the regulation by LaeA and velvet proteins should be a practical strategy in activating silent biosynthetic gene clusters (BGCs) in fungi to obtain previously undiscovered metabolites.
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Affiliation(s)
- Xuwen Hou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Liyao Liu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Dan Xu
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Daowan Lai
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
| | - Ligang Zhou
- MOA Key Lab of Pest Monitoring and Green Management, Department of Plant Pathology, College of Plant Protection, China Agricultural University, Beijing 100193, China
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Marcano Y, Montanares M, Gil-Durán C, González K, Levicán G, Vaca I, Chávez R. Pr laeA Affects the Production of Roquefortine C, Mycophenolic Acid, and Andrastin A in Penicillium roqueforti, but It Has Little Impact on Asexual Development. J Fungi (Basel) 2023; 9:954. [PMID: 37888210 PMCID: PMC10607316 DOI: 10.3390/jof9100954] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/14/2023] [Accepted: 09/20/2023] [Indexed: 10/28/2023] Open
Abstract
The regulation of fungal specialized metabolism is a complex process involving various regulators. Among these regulators, LaeA, a methyltransferase protein originally discovered in Aspergillus spp., plays a crucial role. Although the role of LaeA in specialized metabolism has been studied in different fungi, its function in Penicillium roqueforti remains unknown. In this study, we employed CRISPR-Cas9 technology to disrupt the laeA gene in P. roqueforti (PrlaeA) aiming to investigate its impact on the production of the specialized metabolites roquefortine C, mycophenolic acid, and andrastin A, as well as on asexual development, because they are processes that occur in the same temporal stages within the physiology of the fungus. Our results demonstrate a substantial reduction in the production of the three metabolites upon disruption of PrlaeA, suggesting a positive regulatory role of LaeA in their biosynthesis. These findings were further supported by qRT-PCR analysis, which revealed significant downregulation in the expression of genes associated with the biosynthetic gene clusters (BGCs) responsible for producing roquefortine C, mycophenolic acid, and andrastin A in the ΔPrlaeA strains compared with the wild-type P. roqueforti. Regarding asexual development, the disruption of PrlaeA led to a slight decrease in colony growth rate, while conidiation and conidial germination remained unaffected. Taken together, our results suggest that LaeA positively regulates the expression of the analyzed BGCs and the production of their corresponding metabolites in P. roqueforti, but it has little impact on asexual development.
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Affiliation(s)
- Yudethzi Marcano
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Mariana Montanares
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Carlos Gil-Durán
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Kathia González
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Gloria Levicán
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
| | - Inmaculada Vaca
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Renato Chávez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Santiago 9170022, Chile; (Y.M.); (C.G.-D.); (K.G.); (G.L.)
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3
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Yu W, Pei R, Zhou J, Zeng B, Tu Y, He B. Molecular regulation of fungal secondary metabolism. World J Microbiol Biotechnol 2023; 39:204. [PMID: 37209190 DOI: 10.1007/s11274-023-03649-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
Many bioactive secondary metabolites synthesized by fungi have important applications in many fields, such as agriculture, food, medical and others. The biosynthesis of secondary metabolites is a complex process involving a variety of enzymes and transcription factors, which are regulated at different levels. In this review, we describe our current understanding on molecular regulation of fungal secondary metabolite biosynthesis, such as environmental signal regulation, transcriptional regulation and epigenetic regulation. The effects of transcription factors on the secondary metabolites produced by fungi were mainly introduced. It was also discussed that new secondary metabolites could be found in fungi and the production of secondary metabolites could be improved. We also highlight the importance of understanding the molecular regulation mechanisms to activate silent secondary metabolites and uncover their physiological and ecological functions. By comprehensively understanding the regulatory mechanisms involved in secondary metabolite biosynthesis, we can develop strategies to improve the production of these compounds and maximize their potential benefits.
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Affiliation(s)
- Wenbin Yu
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, China
| | - Rongqiang Pei
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, China
| | - Jingyi Zhou
- Zhanjiang Preschool Education College, Zhanjiang, 524084, Guangdong, China
| | - Bin Zeng
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, China
- College of Pharmacy, Shenzhen Technology University, Shenzhen, 518000, Guangdong, China
| | - Yayi Tu
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, China.
| | - Bin He
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, China.
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Fernandez-Bunster G. Diversity, Phylogenetic Profiling of Genus Penicillium, and Their Potential Applications. Fungal Biol 2021. [DOI: 10.1007/978-3-030-67561-5_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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El Hajj Assaf C, Zetina-Serrano C, Tahtah N, Khoury AE, Atoui A, Oswald IP, Puel O, Lorber S. Regulation of Secondary Metabolism in the Penicillium Genus. Int J Mol Sci 2020; 21:E9462. [PMID: 33322713 PMCID: PMC7763326 DOI: 10.3390/ijms21249462] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022] Open
Abstract
Penicillium, one of the most common fungi occurring in a diverse range of habitats, has a worldwide distribution and a large economic impact on human health. Hundreds of the species belonging to this genus cause disastrous decay in food crops and are able to produce a varied range of secondary metabolites, from which we can distinguish harmful mycotoxins. Some Penicillium species are considered to be important producers of patulin and ochratoxin A, two well-known mycotoxins. The production of these mycotoxins and other secondary metabolites is controlled and regulated by different mechanisms. The aim of this review is to highlight the different levels of regulation of secondary metabolites in the Penicillium genus.
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Affiliation(s)
- Christelle El Hajj Assaf
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Institute for Agricultural and Fisheries Research (ILVO), member of Food2Know, Brusselsesteenweg 370, 9090 Melle, Belgium
| | - Chrystian Zetina-Serrano
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Nadia Tahtah
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - André El Khoury
- Centre D’analyse et de Recherche, Unité de Recherche Technologies et Valorisations Agro-Alimentaires, Faculté des Sciences, Université Saint-Joseph, P.O. Box 17-5208, Mar Mikhael, Beirut 1104, Lebanon;
| | - Ali Atoui
- Laboratory of Microbiology, Department of Life and Earth Sciences, Faculty of Sciences I, Lebanese University, Hadath Campus, P.O. Box 5, Beirut 1104, Lebanon;
| | - Isabelle P. Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
| | - Sophie Lorber
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, INP-Purpan, UPS, 31027 Toulouse, France; (C.E.H.A.); (C.Z.-S.); (N.T.); (I.P.O.); (S.L.)
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Cheng M, Zhao S, Lin C, Song J, Yang Q. Requirement of LaeA for sporulation, pigmentation and secondary metabolism in Chaetomium globosum. Fungal Biol 2020; 125:305-315. [PMID: 33766309 DOI: 10.1016/j.funbio.2020.11.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 10/22/2020] [Accepted: 11/24/2020] [Indexed: 10/22/2022]
Abstract
The global regulator LaeA has been confirmed to govern the production of secondary metabolites in fungi. Herein, we examined the role of LaeA in Chaetomium globosum. Similarly as observed in other filamentous, CgLaeA had a significant effect on the secondary metabolism. The ΔCglaeA mutant strain did not exhibit chaetoglobosin A, whereas its production was restored in the CglaeAC strain. In addition, CglaeA overexpression led to an increase in chaetoglobosin A production. Transcriptional examination of the mutants indicated that CgLaeA positively regulated the expression of pathway-specific transcription factor CgcheR, while another global regulator CgvelB was negatively regulated by CgLaeA. Furthermore, CgLaeA also affected the morphological phenotypes of fungi. The ΔCglaeA mutant strains exhibited decreased sporulation and pigmentation compared with the wild-type strain, whereas the phenotypes were restored in the CglaeAC strain. Moreover, OE::CglaeA exhibited increased levels of sporulation and pigmentation. Moreover, inhibition activity against phytopathogenic fungi affected by decreased mycotoxin production of the ΔCglaeA mutant strain.
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Affiliation(s)
- Ming Cheng
- School of Life Sciences and Technology, Harbin Institute of Technology, Harbin, 150000, China
| | - Shanshan Zhao
- School of Life Sciences and Technology, Harbin Institute of Technology, Harbin, 150000, China
| | - Congyu Lin
- School of Life Sciences and Technology, Harbin Institute of Technology, Harbin, 150000, China
| | - Jinzhu Song
- School of Life Sciences and Technology, Harbin Institute of Technology, Harbin, 150000, China
| | - Qian Yang
- School of Life Sciences and Technology, Harbin Institute of Technology, Harbin, 150000, China.
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7
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Itoh H, Miura A, Takeda I, Matsui M, Tamano K, Machida M, Shibata T. Search for transcription factors affecting productivity of the polyketide FR901512 in filamentous fungal sp. No. 14919 and identification of Drf1, a novel negative regulator of the biosynthetic gene cluster. Biosci Biotechnol Biochem 2019; 83:1163-1170. [PMID: 30821612 DOI: 10.1080/09168451.2019.1584519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In order to increase secondary metabolite production in filamentous fungi, a transcription factor gene in the biosynthetic gene cluster and global regulator genes such as laeA are considered plausible as targets for overexpression by genetic modification. In this study, we examined these overexpression effect in fungal sp. No. 14919 that produces FR901512, an HMG-CoA reductase inhibitor. Resultantly, the productivity was improved at 1.7-1.8 fold by overexpressing frlE, a transcription factor gene in the biosynthetic gene cluster, whereas productivity did not change by overexpression of laeA and veA. Furthermore, we searched for extra transcription factors affecting the productivity by transcriptome analysis between wild-type strain and highly productive UV mutants. After verifying productivity decrease by overexpression, Drf1, a novel transcription factor encoded by drf1 was identified as the negative regulator. Because each frlE product (FrlE) and Drf1 worked on the same cluster in positive and negative regulatory manners, their network was analyzed.
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Affiliation(s)
- Hiroya Itoh
- a Biotechnology Labs., Astellas Pharma Inc ., Tsukuba , Japan.,b Technology Research Association of Highly Efficient Gene Design (TRAHED) , Tokyo , Japan
| | - Ai Miura
- c Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Sapporo , Japan
| | - Itaru Takeda
- c Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Sapporo , Japan
| | - Makoto Matsui
- b Technology Research Association of Highly Efficient Gene Design (TRAHED) , Tokyo , Japan.,d Pharmaceutical Science & Technology Labs ., Astellas Pharma Inc ., Tsukuba , Japan
| | - Koichi Tamano
- c Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Sapporo , Japan
| | - Masayuki Machida
- b Technology Research Association of Highly Efficient Gene Design (TRAHED) , Tokyo , Japan.,c Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Sapporo , Japan
| | - Takashi Shibata
- b Technology Research Association of Highly Efficient Gene Design (TRAHED) , Tokyo , Japan.,d Pharmaceutical Science & Technology Labs ., Astellas Pharma Inc ., Tsukuba , Japan
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8
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Wang DY, Tong SM, Guan Y, Ying SH, Feng MG. The velvet protein VeA functions in asexual cycle, stress tolerance and transcriptional regulation of Beauveria bassiana. Fungal Genet Biol 2019; 127:1-11. [PMID: 30807832 DOI: 10.1016/j.fgb.2019.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 02/14/2019] [Accepted: 02/21/2019] [Indexed: 10/27/2022]
Abstract
VeA is a key velvet protein that regulates sexual/asexual development and secondary metabolism in filamentous fungi, particularly Aspergilli, but has not been explored yet in asexual insect mycopathogens, such as Beauveria bassiana. Here, we report a localization of B. bassiana VeA in the cytoplasm of hyphal cells exposed to either light or dark cue and its migration to the nucleus only in darkness. Deletion of veA resulted in facilitated hyphal growth and decreased cell length on rich media, light growth defects on scant media, and increased sensitivities to oxidation, high osmolarity and prolonged heat shock during colony growth. Compared to wild-type, the deletion mutant was much more triggered in conidiation at optimal 25 °C in darkness than in a light/dark (L:D) cycle of 12:12, indicating the role of VeA acting as a negative regulator of conidiation in a light-dependent manner. The mutant conidia produced at L:D 12:12 showed defects in germination, thermotolerance and UVB resistance but no change in virulence, contrasting to attenuated virulence for the mutant conidia produced in darkness. Intriguingly, fungal outgrowth and conidiation were markedly suppressed on the surfaces of the mutant-mummified insect cadavers, suggesting a significant role of VeA in fungal survival, dispersal and prevalence in host habitats. Transcriptomic analysis revealed 1248 and 1183 differentially expressed genes in the deletion mutant versus wild-type grown at L:D 0:24 and 12:12 respectively, including those involved in central developmental pathway and secondary metabolism. Altogether, VeA is functionally involved in asexual cycle, stress tolerance and transcriptional regulation of B. bassiana.
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Affiliation(s)
- Ding-Yi Wang
- MOE Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Sen-Miao Tong
- MOE Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; College of Agricultural and Food Science, Zhejiang A&F University, Lin'an, Zhejiang 311300, China.
| | - Yi Guan
- MOE Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; Fujian Key Laboratory of Marine Enzyme Engineering, Fuzhou University, Fuzhou, Fujian 350108, China
| | - Sheng-Hua Ying
- MOE Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Ming-Guang Feng
- MOE Laboratory of Biosystems Homeostasis & Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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The role of the veA gene in adjusting developmental balance and environmental stress response in Aspergillus cristatus. Fungal Biol 2018; 122:952-964. [PMID: 30227931 DOI: 10.1016/j.funbio.2018.05.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 05/16/2018] [Accepted: 05/31/2018] [Indexed: 12/14/2022]
Abstract
veA belongs to the velvet regulatory system that regulates the development and secondary metabolism of many fungi. To identify the function of veA in Aspergillus cristatus, veA deletion mutants were constructed by homologous recombination via Agrobacterium tumefaciens-mediated transformation. Deletion of veA led to increased conidial production and reduced sexual sporulation. The regulatory role of veA in A. cristatus was not light-dependent, and this differed from its role in other Aspergilli. Furthermore, veA deletion mutants were more sensitive to environmental stressors, including salt, osmotic pressure, temperature and pH. In contrast, deletion of veA resulted in increased resistance to oxidative stress. veA also affected aerial vegetative growth. Transcriptomic analysis of the veA-null mutant and wild type indicated that most asexual and sexual development genes were upregulated and downregulated, respectively. These findings confirmed that veA has a positive effect on sexual development but represses conidial formation. Overall, these results suggested that the veA gene plays a critical role in maintaining a developmental balance between asexual and sexual sporulation and is involved in vegetative growth and environmental stress response in A. cristatus.
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El Hajj Assaf C, Snini SP, Tadrist S, Bailly S, Naylies C, Oswald IP, Lorber S, Puel O. Impact of veA on the development, aggressiveness, dissemination and secondary metabolism of Penicillium expansum. MOLECULAR PLANT PATHOLOGY 2018; 19:1971-1983. [PMID: 29517851 PMCID: PMC6638001 DOI: 10.1111/mpp.12673] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 03/02/2018] [Accepted: 03/03/2018] [Indexed: 05/18/2023]
Abstract
Penicillium expansum, the causal agent of blue mould disease, produces the mycotoxins patulin and citrinin amongst other secondary metabolites. Secondary metabolism is associated with fungal development, which responds to numerous biotic and abiotic external triggers. The global transcription factor VeA plays a key role in the coordination of secondary metabolism and differentiation processes in many fungal species. The specific role of VeA in P. expansum remains unknown. A null mutant PeΔveA strain and a complemented PeΔveA:veA strain were generated in P. expansum and their pathogenicity on apples was studied. Like the wild-type and the complemented strains, the null mutant PeΔveA strain was still able to sporulate and to colonize apples, but at a lower rate. However, it could not form coremia either in vitro or in vivo, thus limiting its dissemination from natural substrates. The impact of veA on the expression of genes encoding proteins involved in the production of patulin, citrinin and other secondary metabolites was evaluated. The disruption of veA drastically reduced the production of patulin and citrinin on synthetic media, associated with a marked down-regulation of all genes involved in the biosynthesis of the two mycotoxins. Moreover, the null mutant PeΔveA strain was unable to produce patulin on apples. The analysis of gene expression revealed a global impact on secondary metabolism, as 15 of 35 backbone genes showed differential regulation on two different media. These findings support the hypothesis that VeA contributes to the pathogenicity of P. expansum and modulates its secondary metabolism.
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Affiliation(s)
- Christelle El Hajj Assaf
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
- Flanders Research Institute for Agricultural, Fisheries and Food (ILVO), Technology and Food Science UnitMelle 9090Belgium
| | - Selma P. Snini
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
- Present address:
Université de Toulouse, Laboratoire de Génie Chimique, CNRS, INPT, UPSToulouseFrance
| | - Souria Tadrist
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
| | - Sylviane Bailly
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
| | - Claire Naylies
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
| | - Isabelle P. Oswald
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
| | - Sophie Lorber
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
| | - Olivier Puel
- Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP‐Purpan, UPS31027 ToulouseFrance
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11
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Niehaus EM, Rindermann L, Janevska S, Münsterkötter M, Güldener U, Tudzynski B. Analysis of the global regulator Lae1 uncovers a connection between Lae1 and the histone acetyltransferase HAT1 in Fusarium fujikuroi. Appl Microbiol Biotechnol 2017; 102:279-295. [PMID: 29080998 DOI: 10.1007/s00253-017-8590-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/17/2017] [Accepted: 10/18/2017] [Indexed: 01/08/2023]
Abstract
The fungus Fusarium fujikuroi causes "bakanae" disease of rice due to its ability to produce gibberellins (GAs), a family of plant hormones. Recent genome sequencing revealed the genetic capacity for the biosynthesis of 46 additional secondary metabolites besides the industrially produced GAs. Among them are the pigments bikaverin and fusarubins, as well as mycotoxins, such as fumonisins, fusarin C, beauvericin, and fusaric acid. However, half of the potential secondary metabolite gene clusters are silent. In recent years, it has been shown that the fungal specific velvet complex is involved in global regulation of secondary metabolism in several filamentous fungi. We have previously shown that deletion of the three components of the F. fujikuroi velvet complex, vel1, vel2, and lae1, almost totally abolished biosynthesis of GAs, fumonisins and fusarin C. Here, we present a deeper insight into the genome-wide regulatory impact of Lae1 on secondary metabolism. Over-expression of lae1 resulted in de-repression of GA biosynthetic genes under otherwise repressing high nitrogen conditions demonstrating that the nitrogen repression is overcome. In addition, over-expression of one of five tested histone acetyltransferase genes, HAT1, was capable of returning GA gene expression and GA production to the GA-deficient Δlae1 mutant. Deletion and over-expression of HAT1 in the wild type resulted in downregulation and upregulation of GA gene expression, respectively, indicating that HAT1 together with Lae1 plays an essential role in the regulation of GA biosynthesis.
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Affiliation(s)
- Eva-Maria Niehaus
- Institute for Plant Biology and Biotechnology, Westfälische Wilhelms University Münster, Schlossplatz 8, 48143, Münster, Germany.,Institute of Food Chemistry, Westfälische Wilhelms University Münster, Corrensstr. 45, 48149, Münster, Germany
| | - Lena Rindermann
- Institute for Plant Biology and Biotechnology, Westfälische Wilhelms University Münster, Schlossplatz 8, 48143, Münster, Germany
| | - Slavica Janevska
- Institute for Plant Biology and Biotechnology, Westfälische Wilhelms University Münster, Schlossplatz 8, 48143, Münster, Germany
| | - Martin Münsterkötter
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, Germany Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Ulrich Güldener
- Chair of Genome-oriented Bioinformatics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, 85354, Freising, Germany
| | - Bettina Tudzynski
- Institute for Plant Biology and Biotechnology, Westfälische Wilhelms University Münster, Schlossplatz 8, 48143, Münster, Germany.
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Comparative Transcriptome Analysis of Penicillium citrinum Cultured with Different Carbon Sources Identifies Genes Involved in Citrinin Biosynthesis. Toxins (Basel) 2017; 9:toxins9020069. [PMID: 28230802 PMCID: PMC5331448 DOI: 10.3390/toxins9020069] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/13/2017] [Indexed: 11/17/2022] Open
Abstract
Citrinin is a toxic secondary metabolite of Penicillium citrinum and its contamination in many food items has been widely reported. However, research on the citrinin biosynthesis pathway and its regulation mechanism in P. citrinum is rarely reported. In this study, we investigated the effect of different carbon sources on citrinin production by P. citrinum and used transcriptome analysis to study the underlying molecular mechanism. Our results indicated that glucose, used as the sole carbon source, could significantly promote citrinin production by P. citrinum in Czapek’s broth medium compared with sucrose. A total of 19,967 unigenes were annotated by BLAST in Nr, Nt, Swiss-Prot and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Transcriptome comparison between P. citrinum cultured with sucrose and glucose revealed 1085 differentially expressed unigenes. Among them, 610 were upregulated while 475 were downregulated under glucose as compared to sucrose. KEGG pathway and Gene ontology (GO) analysis indicated that many metabolic processes (e.g., carbohydrate, secondary metabolism, fatty acid and amino acid metabolism) were affected, and potentially interesting genes that encoded putative components of signal transduction, stress response and transcription factor were identified. These genes obviously had important impacts on their regulation in citrinin biosynthesis, which provides a better understanding of the molecular mechanism of citrinin biosynthesis by P. citrinum.
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Jiang T, Wang M, Li L, Si J, Song B, Zhou C, Yu M, Wang X, Zhang Y, Ding G, Zou Z. Overexpression of the Global Regulator LaeA in Chaetomium globosum Leads to the Biosynthesis of Chaetoglobosin Z. JOURNAL OF NATURAL PRODUCTS 2016; 79:2487-2494. [PMID: 27759375 DOI: 10.1021/acs.jnatprod.6b00333] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Overexpression of laeA in Chaetomium globosum CBS148.51 up-regulated expression of the chaetoglobosin gene cluster and resulted in the isolation of a new cytochalasan, chaetoglobosin Z (1), together with six known analogues, chaetoglobosins A (2), B (3), D (4), E (5), O (6), and V (7). RT-PCR analysis confirmed that the key genes in the chaetoglobosin gene cluster were significantly up-regulated. The structure of the new compound chaetoglobosin Z (1) was elucidated using NMR data. The relative and absolute configurations were determined by NOESY and electronic circular dichroism combined with quantum-chemical calculations adopting time-dependent density functional theory methods, respectively. These compounds displayed strong biological effects against the HepG 2 cell line compared with the positive control. The results further supported that LaeA is a global regulator that could up-regulate and/or activate cryptic gene clusters to produce new secondary metabolites.
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Affiliation(s)
- Tao Jiang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
| | - Menghua Wang
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
| | - Li Li
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica , Beijing 100050, People's Republic of China
| | - Jinguang Si
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
- School of Pharmacy, Henan University of Traditional Chinese Medicine , Zhengzhou 450046, People's Republic of China
| | - Bo Song
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
| | - Cao Zhou
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
| | - Meng Yu
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
| | - Xuewei Wang
- Institute of Microbiology, Chinese Academy of Sciences , Beijing 100090, People's Republic of China
| | - Yonggang Zhang
- Key Laboratory for Applied Microbiology of Shandong Province , Jinan 250014, People's Republic of China
| | - Gang Ding
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica , Beijing 100050, People's Republic of China
| | - Zhongmei Zou
- Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development , Beijing, 100193, People's Republic of China
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14
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Wang R, Leng Y, Shrestha S, Zhong S. Coordinated and independent functions of velvet-complex genes in fungal development and virulence of the fungal cereal pathogen Cochliobolus sativus. Fungal Biol 2016; 120:948-960. [PMID: 27521627 DOI: 10.1016/j.funbio.2016.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/25/2016] [Accepted: 05/09/2016] [Indexed: 12/31/2022]
Abstract
LaeA and velvet proteins regulate fungal development and secondary metabolism through formation of multimeric complexes in many fungal species, but their functions in the cereal fungal pathogen Cochliobolus sativus are not well understood. In this study, four velvet complex genes (CsLaeA, CsVeA, CsVelB, and CsVelC) in C. sativus were identified and characterized using knockout mutants generated for each of the genes. Both ΔCsVeA and ΔCsVelB showed significant reduction in aerial mycelia growth. ΔCsVelB also exhibited a hypermorphic conidiation phenotype with indeterminate growth of the conidial tip cells and premature germination of conidia. ΔCsLaeA, ΔCsVeA, and ΔCsVelB produced more conidia under constant dark conditions than under constant light conditions whereas no differences were observed under the two conditions for the wild type. These three mutants also showed significantly reduced conidiation under constant light conditions, but produced more small sized conidia under constant dark conditions compared to the wild type. All knockout mutants (ΔCsLaeA, ΔCsVeA, ΔCsVelB and ΔCsVelC) showed some extent of reduction in virulence on susceptible barley plants compared to the wild type strain. The results revealed the conserved and unique roles of velvet-complex proteins as regulators in mediating fungal development and secondary metabolism in C. sativus.
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Affiliation(s)
- Rui Wang
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Yueqiang Leng
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Subidhya Shrestha
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA
| | - Shaobin Zhong
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108, USA.
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15
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Liu Q, Cai L, Shao Y, Zhou Y, Li M, Wang X, Chen F. Inactivation of the global regulator LaeA in Monascus ruber results in a species-dependent response in sporulation and secondary metabolism. Fungal Biol 2015; 120:297-305. [PMID: 26895858 DOI: 10.1016/j.funbio.2015.10.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 10/27/2015] [Accepted: 10/28/2015] [Indexed: 12/31/2022]
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.
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Affiliation(s)
- Qingpei Liu
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China
| | - Li Cai
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, Hubei Province, PR China
| | - Yanchun Shao
- 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
| | - Youxiang Zhou
- Institute of Quality Standard and Testing Technology for Agro-Products, Hubei Academy of Agricultural Sciences, Wuhan 430070, Hubei Province, PR China
| | - Mu Li
- 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
| | - Xiaohong Wang
- 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.
| | - Fusheng Chen
- 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.
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Griffiths S, Saccomanno B, de Wit PJ, Collemare J. Regulation of secondary metabolite production in the fungal tomato pathogen Cladosporium fulvum. Fungal Genet Biol 2015; 84:52-61. [DOI: 10.1016/j.fgb.2015.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 09/23/2015] [Accepted: 09/24/2015] [Indexed: 12/15/2022]
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17
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Wang R, Leng Y, Zhong S. The regulatory gene VosA affects conidiogenesis and is involved in virulence of the fungal cereal pathogen Cochliobolus sativus. Fungal Biol 2015; 119:884-900. [DOI: 10.1016/j.funbio.2015.06.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 11/25/2022]
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18
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Aghcheh RK, Kubicek CP. Epigenetics as an emerging tool for improvement of fungal strains used in biotechnology. Appl Microbiol Biotechnol 2015; 99:6167-81. [PMID: 26115753 DOI: 10.1007/s00253-015-6763-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 06/07/2015] [Accepted: 06/10/2015] [Indexed: 10/23/2022]
Abstract
Filamentous fungi are today a major source of industrial biotechnology for the production of primary and secondary metabolites, as well as enzymes and recombinant proteins. All of them have undergone extensive improvement strain programs, initially by classical mutagenesis and later on by genetic manipulation. Thereby, strategies to overcome rate-limiting or yield-reducing reactions included manipulating the expression of individual genes, their regulatory genes, and also their function. Yet, research of the last decade clearly showed that cells can also undergo heritable changes in gene expression that do not involve changes in the underlying DNA sequences (=epigenetics). This involves three levels of regulation: (i) DNA methylation, (ii) chromatin remodeling by histone modification, and (iii) RNA interference. The demonstration of the occurrence of these processes in fungal model organisms such as Aspergillus nidulans and Neurospora crassa has stimulated its recent investigation as a tool for strain improvement in industrially used fungi. This review describes the progress that has thereby been obtained.
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Affiliation(s)
- Razieh Karimi Aghcheh
- Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/166-5, 1060, Vienna, Austria,
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19
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Hong EJ, Kim NK, Lee D, Kim WG, Lee I. Overexpression of the laeA gene leads to increased production of cyclopiazonic acid in Aspergillus fumisynnematus. Fungal Biol 2015; 119:973-983. [PMID: 26466873 DOI: 10.1016/j.funbio.2015.06.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Revised: 06/08/2015] [Accepted: 06/11/2015] [Indexed: 01/05/2023]
Abstract
To explore novel bioactive compounds produced via activation of secondary metabolite (SM) gene clusters, we overexpressed an ortholog of laeA, a gene that encodes a global positive regulator of secondary metabolism in Aspergillus fumisynnematus F746. Overexpression of the laeA gene under the alcA promoter resulted in the production of less pigment, shorter conidial head chains, and fewer conidia. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analysis revealed that SM production in OE::laeA was significantly increased, and included new metabolites that were not detected in the wild type. Among them, a compound named F1 was selected on the basis of its high production levels and antibacterial effects. F1 was purified by column chromatography and preparative TLC and identified as cyclopiazonic acid (CPA) by LC/MS, which had been previously known as mycotoxin. As A. fumisynnematus was not known to produce CPA, these results suggest that overexpression of the laeA gene can be used to explore the synthesis of useful bioactive compounds, even in a fungus for which the genome sequence is unavailable.
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Affiliation(s)
- Eun Jin Hong
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 136-702, Republic of Korea
| | - Na Kyeong Kim
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 136-702, Republic of Korea
| | - Doyup Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 136-702, Republic of Korea
| | - Won Gon Kim
- Functional Metabolite Research Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong, Daejeon 305-806, Republic of Korea
| | - Inhyung Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul 136-702, Republic of Korea.
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20
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Gerke J, Braus GH. Manipulation of fungal development as source of novel secondary metabolites for biotechnology. Appl Microbiol Biotechnol 2014; 98:8443-55. [PMID: 25142695 PMCID: PMC4192562 DOI: 10.1007/s00253-014-5997-8] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 07/25/2014] [Accepted: 07/28/2014] [Indexed: 12/19/2022]
Abstract
Fungal genomics revealed a large potential of yet-unexplored secondary metabolites, which are not produced during vegetative growth. The discovery of novel bioactive compounds is increasingly gaining importance. The high number of resistances against established antibiotics requires novel drugs to counteract increasing human and animal mortality rates. In addition, growth of plant pathogens has to be controlled to minimize harvest losses. An additional critical issue is the post-harvest production of deleterious mycotoxins. Fungal development and secondary metabolite production are linked processes. Therefore, molecular regulators of development might be suitable to discover new bioactive fungal molecules or to serve as targets to control fungal growth, development, or secondary metabolite production. The fungal impact is relevant as well for our healthcare systems as for agriculture. We propose here to use the knowledge about mutant strains discovered in fungal model systems for a broader application to detect and explore new fungal drugs or toxins. As examples, mutant strains impaired in two conserved eukaryotic regulatory complexes are discussed. The COP9 signalosome (CSN) and the velvet complex act at the interface between development and secondary metabolism. The CSN is a multi-protein complex of up to eight subunits and controls the activation of CULLIN-RING E3 ubiquitin ligases, which mark substrates with ubiquitin chains for protein degradation by the proteasome. The nuclear velvet complex consists of the velvet-domain proteins VeA and VelB and the putative methyltransferase LaeA acting as a global regulator for secondary metabolism. Defects in both complexes disturb fungal development, light perception, and the control of secondary metabolism. The potential biotechnological relevance of these developmental fungal mutant strains for drug discovery, agriculture, food safety, and human healthcare is discussed.
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Affiliation(s)
- Jennifer Gerke
- Institut für Mikrobiologie & Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Göttingen, Germany
| | - Gerhard H. Braus
- Institut für Mikrobiologie & Genetik, Georg-August-Universität, Grisebachstr. 8, D-37077 Göttingen, Germany
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21
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Strategies for mining fungal natural products. J Ind Microbiol Biotechnol 2013; 41:301-13. [PMID: 24146366 DOI: 10.1007/s10295-013-1366-3] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 10/05/2013] [Indexed: 10/26/2022]
Abstract
Fungi are well known for their ability to produce a multitude of natural products. On the one hand their potential to provide beneficial antibiotics and immunosuppressants has been maximized by the pharmaceutical industry to service the market with cost-efficient drugs. On the other hand identification of trace amounts of known mycotoxins in food and feed samples is of major importance to ensure consumer health and safety. Although several fungal natural products, their biosynthesis and regulation are known today, recent genome sequences of hundreds of fungal species illustrate that the secondary metabolite potential of fungi has been substantially underestimated. Since expression of genes and subsequent production of the encoded metabolites are frequently cryptic or silent under standard laboratory conditions, strategies for activating these hidden new compounds are essential. This review will cover the latest advances in fungal genome mining undertaken to unlock novel products.
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Qin Y, Bao L, Gao M, Chen M, Lei Y, Liu G, Qu Y. Penicillium decumbens BrlA extensively regulates secondary metabolism and functionally associates with the expression of cellulase genes. Appl Microbiol Biotechnol 2013; 97:10453-67. [PMID: 24113825 DOI: 10.1007/s00253-013-5273-3] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 09/03/2013] [Accepted: 09/05/2013] [Indexed: 12/15/2022]
Abstract
Penicillium decumbens has been used in the industrial production of lignocellulolytic enzymes in China for more than 15 years. Conidiation is essential for most industrial fungi because conidia are used as starters in the first step of fermentation. To investigate the mechanism of conidiation in P. decumbens, we generated mutants defective in two central regulators of conidiation, FluG and BrlA. Deletion of fluG resulted in neither "fluffy" phenotype nor alteration in conidiation, indicating possible different upstream mechanisms activating brlA between P. decumbens and Aspergillus nidulans. Deletion of brlA completely blocked conidiation. Further investigation of brlA expression in different media (nutrient-rich or nutrient-poor) and different culture states (liquid or solid) showed that brlA expression is required but not sufficient for conidiation. The brlA deletion strain exhibited altered hyphal morphology with more branches. Genome-wide expression profiling identified BrlA-dependent genes in P. decumbens, including genes previously reported to be involved in conidiation as well as previously reported chitin synthase genes and acid protease gene (pepB). The expression levels of seven secondary metabolism gene clusters (from a total of 28 clusters) were drastically regulated in the brlA deletion strain, including a downregulated cluster putatively involved in the biosynthesis of the mycotoxins roquefortine C and meleagrin. In addition, the expression levels of most cellulase genes were upregulated in the brlA deletion strain detected by real-time quantitative PCR. The brlA deletion strain also exhibited an 89.1 % increase in cellulase activity compared with the wild-type strain. The results showed that BrlA in P. decumbens not only has a key role in regulating conidiation, but it also regulates secondary metabolism extensively as well as the expression of cellulase genes.
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Affiliation(s)
- Yuqi Qin
- National Glycoengineering Research Center, Shandong University, 27, Shanda South Road, Jinan, Shandong, 250100, China,
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VeA regulates conidiation, gliotoxin production, and protease activity in the opportunistic human pathogen Aspergillus fumigatus. EUKARYOTIC CELL 2012; 11:1531-43. [PMID: 23087369 DOI: 10.1128/ec.00222-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Invasive aspergillosis by Aspergillus fumigatus is a leading cause of infection-related mortality in immunocompromised patients. In this study, we show that veA, a major conserved regulatory gene that is unique to fungi, is necessary for normal morphogenesis in this medically relevant fungus. Although deletion of veA results in a strain with reduced conidiation, overexpression of this gene further reduced conidial production, indicating that veA has a major role as a regulator of development in A. fumigatus and that normal conidiation is only sustained in the presence of wild-type VeA levels. Furthermore, our studies revealed that veA is a positive regulator in the production of gliotoxin, a secondary metabolite known to be a virulent factor in A. fumigatus. Deletion of veA resulted in a reduction of gliotoxin production with respect to that of the wild-type control. This reduction in toxin coincided with a decrease in gliZ and gliP expression, which is necessary for gliotoxin biosynthesis. Interestingly, veA also influences protease activity in this organism. Specifically, deletion of veA resulted in a reduction of protease activity; this is the first report of a veA homolog with a role in controlling fungal hydrolytic activity. Although veA affects several cellular processes in A. fumigatus, pathogenicity studies in a neutropenic mouse infection model indicated that veA is dispensable for virulence.
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Lim FY, Sanchez JF, Wang CC, Keller NP. Toward awakening cryptic secondary metabolite gene clusters in filamentous fungi. Methods Enzymol 2012; 517:303-24. [PMID: 23084945 PMCID: PMC3703436 DOI: 10.1016/b978-0-12-404634-4.00015-2] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Mining for novel natural compounds is of eminent importance owing to the continuous need for new pharmaceuticals. Filamentous fungi are historically known to harbor the genetic capacity for an arsenal of natural compounds, both beneficial and detrimental to humans. The majority of these metabolites are still cryptic or silent under standard laboratory culture conditions. Mining for these cryptic natural products can be an excellent source for identifying new compound classes. Capitalizing on the current knowledge on how secondary metabolite gene clusters are regulated has allowed the research community to unlock many hidden fungal treasures, as described in this chapter.
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Affiliation(s)
- Fang Yun Lim
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA
| | - James F. Sanchez
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, Los Angeles, California, USA
| | - Clay C.C. Wang
- Department of Pharmacology and Pharmaceutical Sciences, University of Southern California, School of Pharmacy, Los Angeles, California, USA,Department of Chemistry, University of Southern California, College of Letters, Arts, and Sciences, Los Angeles, California, USA
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, USA,Corresponding author:
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