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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: 0] [Impact Index Per Article: 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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Yu W, Pei R, Zhang Y, Tu Y, He B. Light regulation of secondary metabolism in fungi. J Biol Eng 2023; 17:57. [PMID: 37653453 PMCID: PMC10472637 DOI: 10.1186/s13036-023-00374-4] [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: 07/03/2023] [Accepted: 08/22/2023] [Indexed: 09/02/2023] Open
Abstract
Fungi have evolved unique metabolic regulation mechanisms for adapting to the changing environments. One of the key features of fungal adaptation is the production of secondary metabolites (SMs), which are essential for survival and beneficial to the organism. Many of these SMs are produced in response to the environmental cues, such as light. In all fungal species studied, the Velvet complex transcription factor VeA is a central player of the light regulatory network. In addition to growth and development, the intensity and wavelength of light affects the formation of a broad range of secondary metabolites. Recent studies, mainly on species of the genus Aspergillus, revealed that the dimer of VeA-VelB and LaeA does not only regulate gene expression in response to light, but can also be involved in regulating production of SMs. Furthermore, the complexes have a wide regulatory effect on different types of secondary metabolites. In this review, we discussed the role of light in the regulation of fungal secondary metabolism. In addition, we reviewed the photoreceptors, transcription factors, and signaling pathways that are involved in light-dependent regulation of secondary metabolism. The effects of transcription factors on the production of secondary metabolites, as well as the potential applications of light regulation for the production of pharmaceuticals and other products were discussed. Finally, we provided an overview of the current research in this field and suggested potential areas for future research.
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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
| | - Yufei Zhang
- Jiangxi Key Laboratory of Bioprocess Engineering, College of Life Sciences, Jiangxi Science & Technology Normal University, Nanchang, 330013, Jiangxi, 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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Zhao Z, Gu S, Liu D, Liu D, Chen B, Li J, Tian C. The putative methyltransferase LaeA regulates mycelium growth and cellulase production in Myceliophthora thermophila. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:58. [PMID: 37013645 PMCID: PMC10071736 DOI: 10.1186/s13068-023-02313-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/28/2023] [Indexed: 04/05/2023]
Abstract
BACKGROUND Filamentous fungi with the ability to use complex carbon sources has been developed as platforms for biochemicals production. Myceliophthora thermophila has been developed as the cell factory to produce lignocellulolytic enzymes and plant biomass-based biofuels and biochemicals in biorefinery. However, low fungal growth rate and cellulose utilization efficiency are significant barriers to the satisfactory yield and productivity of target products, which needs our further exploration and improvement. RESULTS In this study, we comprehensively explored the roles of the putative methyltransferase LaeA in regulating mycelium growth, sugar consumption, and cellulases expression. Deletion of laeA in thermophile fungus Myceliophthora thermophila enhanced mycelium growth and glucose consumption significantly. Further exploration of LaeA regulatory network indicated that multiple growth regulatory factors (GRF) Cre-1, Grf-1, Grf-2, and Grf-3, which act as negative repressors of carbon metabolism, were regulated by LaeA in this fungus. We also determined that phosphoenolpyruvate carboxykinase (PCK) is the core node of the metabolic network related to fungal vegetative growth, of which enhancement partially contributed to the elevated sugar consumption and fungal growth of mutant ΔlaeA. Noteworthily, LaeA participated in regulating the expression of cellulase genes and their transcription regulator. ΔlaeA exhibited 30.6% and 5.5% increases in the peak values of extracellular protein and endo-glucanase activity, respectively, as compared to the WT strain. Furthermore, the global histone methylation assays indicated that LaeA is associated with modulating H3K9 methylation levels. The normal function of LaeA on regulating fungal physiology is dependent on methyltransferase activity. CONCLUSIONS The research presented in this study clarified the function and elucidated the regulatory network of LaeA in the regulation of fungal growth and cellulase production, which will significantly deepen our understanding about the regulation mechanism of LaeA in filamentous fungi and provides the new strategy for improvement the fermentation properties of industrial fungal strain by metabolic engineering.
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Affiliation(s)
- Zhen Zhao
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shuying Gu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Defei Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Dandan Liu
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Bingchen Chen
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China
| | - Jingen Li
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
| | - Chaoguang Tian
- Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
- National Technology Innovation Center of Synthetic Biology, Tianjin, 300308, China.
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4
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Wang W, Liang X, Li Y, Wang P, Keller NP. Genetic Regulation of Mycotoxin Biosynthesis. J Fungi (Basel) 2022; 9:jof9010021. [PMID: 36675842 PMCID: PMC9861139 DOI: 10.3390/jof9010021] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/20/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Mycotoxin contamination in food poses health hazards to humans. Current methods of controlling mycotoxins still have limitations and more effective approaches are needed. During the past decades of years, variable environmental factors have been tested for their influence on mycotoxin production leading to elucidation of a complex regulatory network involved in mycotoxin biosynthesis. These regulators are putative targets for screening molecules that could inhibit mycotoxin synthesis. Here, we summarize the regulatory mechanisms of hierarchical regulators, including pathway-specific regulators, global regulators and epigenetic regulators, on the production of the most critical mycotoxins (aflatoxins, patulin, citrinin, trichothecenes and fumonisins). Future studies on regulation of mycotoxins will provide valuable knowledge for exploring novel methods to inhibit mycotoxin biosynthesis in a more efficient way.
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Affiliation(s)
- Wenjie Wang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Correspondence: (W.W.); (N.P.K.)
| | - Xinle Liang
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Yudong Li
- School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
- Institute of Food Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Pinmei Wang
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
- Correspondence: (W.W.); (N.P.K.)
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5
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Mahata PK, Dass RS, Gunti L, Thorat PA. First report on the metabolic characterization of Sterigmatocystin production by select Aspergillus species from the Nidulantes section in Foeniculum vulgare. Front Microbiol 2022; 13:958424. [PMID: 36090109 PMCID: PMC9459157 DOI: 10.3389/fmicb.2022.958424] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 08/03/2022] [Indexed: 12/16/2022] Open
Abstract
Spices are typically grown in climates that support the growth of toxigenic fungi and the production of mycotoxins. The Aspergilli described in this study, as well as the sterigmatocystin (STC) detected, are causes for concern due to their potential to induce food poisoning. One of the most well-known producers of the carcinogenic STC is Aspergillus nidulans. This research explores the occurrence of STC-producing fungi in Foeniculum vulgare, a spice that is marketed in India and other parts of the world. This innovative study details the mycotoxigenic potential of five Aspergilli belonging to Section Nidulantes, namely Aspergillus latus (02 isolates), Emericella quadrilineata (02 isolates), and Aspergillus nidulans (01 isolate), with respect to STC contamination. These five isolates of Aspergilli were screened to produce STC on yeast extract sucrose (YES) medium in a controlled environment with regard to light, temperature, pH, and humidity, among other variables. The expression patterns of regulatory genes, namely, aflR, laeA, pacC, fluG, flbA, pksA, and mtfA were studied on the Czapek–Dox agar (CDA) medium. STC biosynthesis by the test isolates was done in potato dextrose broth (PDB) under optimum conditions, followed by the extraction and purification of the broth using ethyl acetate. High-performance liquid chromatography (HPLC) with an ultraviolet (UV) detector was utilized to detect compounds in eluted samples. F. vulgare contains Aspergilli that have been shown to have mycotoxigenic potential, which can accumulate in the spice during its active growth and thereby cause the elaboration of mycotoxins.
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Wei Z, Shu D, Sun Q, Chen DB, Li ZM, Luo D, Yang J, Tan H. The BcLAE1 is involved in the regulation of ABA biosynthesis in Botrytis cinerea TB-31. Front Microbiol 2022; 13:969499. [PMID: 35992717 PMCID: PMC9386520 DOI: 10.3389/fmicb.2022.969499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Abscisic acid (ABA), as a classic plant hormone, is a key factor in balancing the metabolism of endogenous plant hormones, and plays an important role in regulating the activation of mammalian innate immune cells and glucose homeostasis. Currently, Botrytis cinerea has been used for fermentation to produce ABA. However, the mechanism of the regulation of ABA biosynthesis in B. cinerea is still not fully understood. The putative methyltransferase LaeA/LAE1 is a global regulator involved in the biosynthesis of a variety of secondary metabolites in filamentous fungi. In this study, we demonstrated that BcLAE1 plays an important role in the regulation of ABA biosynthesis in B. cinerea TB-31 by knockout experiment. The deletion of Bclae1 caused a 95% reduction in ABA yields, accompanied by a decrease of the transcriptional level of the ABA synthesis gene cluster Bcaba1-4. Further RNA-seq analysis indicated that deletion of Bclae1 also affected the expression level of key enzymes of BOA and BOT in secondary metabolism, and accompanied by clustering regulatory features. Meanwhile, we found that BcLAE1 is involved in epigenetic regulation as a methyltransferase, with enhanced H3K9me3 modification and attenuated H3K4me2 modification in ΔBclae1 mutant, and this may be a strategy for BcLAE1 to regulate ABA synthesis.
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Affiliation(s)
- Zhao Wei
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Key Laboratory of Bio-Resources and Eco-Environment Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Dan Shu
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- *Correspondence: Dan Shu,
| | - Qun Sun
- Key Laboratory of Bio-Resources and Eco-Environment Ministry of the Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Dong-bo Chen
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- University of the Chinese Academy of Sciences, Beijing, China
| | - Zhe-min Li
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Di Luo
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Jie Yang
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Hong Tan
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
- Hong Tan,
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7
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Wang L, Liu J, Li X, Lyu X, Liu Z, Zhao H, Jiao X, Zhang W, Xie J, Liu W. A histone H3K9 methyltransferase Dim5 mediates repression of sorbicillinoid biosynthesis in Trichoderma reesei. Microb Biotechnol 2022; 15:2533-2546. [PMID: 35921310 PMCID: PMC9518983 DOI: 10.1111/1751-7915.14103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 06/05/2022] [Indexed: 11/27/2022] Open
Abstract
Sorbicillinoids (also termed yellow pigment) are derived from either marine or terrestrial fungi, exhibit various biological activities and therefore show potential as commercial products for human or animal health. The cellulolytic filamentous fungus Trichoderma reesei is capable to biosynthesize sorbicillinoids, but the underlying regulatory mechanism is not yet completely clear. Herein, we identified a histone H3 lysine 9 (H3K9) methyltransferase, Dim5, in T. reesei. TrDIM5 deletion caused an impaired vegetative growth as well as conidiation, whereas the ∆Trdim5 strain displayed a remarkable increase in sorbicillinoid production. Post TrDIM5 deletion, the transcription of sorbicillinoid biosynthesis‐related (SOR) genes was significantly upregulated with a more open chromatin structure. Intriguingly, hardly any expression changes occurred amongst those genes located on both flanks of the SOR gene cluster. In addition, the assays provided evidence that H3K9 triple methylation (H3K9me3) modification acted as a repressive marker at the SOR gene cluster and thus directly mediated the repression of sorbicillinoid biosynthesis. Transcription factor Ypr1 activated the SOR gene cluster by antagonizing TrDim5‐mediated repression and therefore contributed to forming a relatively more open local chromatin environment, which further facilitated its binding and SOR gene expression. The results of this study will contribute to understanding the intricate regulatory network in sorbicillinoid biosynthesis and facilitate the endowment of T. reesei with preferred features for sorbicillinoid production by genetic engineering.
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Affiliation(s)
- Lei Wang
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Jialong Liu
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Xiaotong Li
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Xinxing Lyu
- Institute of Basic Medicine, Shandong First Medical University&Shandong Academy of Medical Sciences, Jinan, China
| | - Zhizhen Liu
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Hong Zhao
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Xiangying Jiao
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Weixin Zhang
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Jun Xie
- Collaborative Innovation Center of Reverse Microbial Etiology, Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, China
| | - Weifeng Liu
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
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8
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LaeA regulates morphological development and ochratoxin A biosynthesis in Aspergillus niger. Mycotoxin Res 2022; 38:221-229. [PMID: 35879501 DOI: 10.1007/s12550-022-00463-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 07/01/2022] [Accepted: 07/19/2022] [Indexed: 10/16/2022]
Abstract
The global regulator LaeA and its orthologs govern the morphogenetic development and secondary metabolism of several filamentous ascomycetes. In Aspergillus niger, it has been shown that an LaeA ortholog (AnLaeA) regulates the production of citric acid and secondary metabolites. In this work, we constructed AnlaeA disruption and overexpression strains to investigate the roles of AnLaeA in morphological development and ochratoxin A (OTA) biosynthesis in A. niger. Phenotypic observation, chemical analysis, and gene expression analysis indicated that AnLaeA acts as a negative regulator of conidial morphogenesis and positively regulates gene expression of the OTA cluster in A. niger grown in CYA medium. However, it was observed that the upregulation of gene expression of the OTA cluster does not necessarily increase OTA production. Our results contribute to a better understanding of the AnlaeA regulatory mechanism and suggest the AnlaeA gene as a potential target for developing control strategies for A. niger infection and OTA biosynthesis.
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9
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Yang K, Tian J, Keller NP. Post-translational modifications drive secondary metabolite biosynthesis in Aspergillus: a review. Environ Microbiol 2022; 24:2857-2881. [PMID: 35645150 PMCID: PMC9545273 DOI: 10.1111/1462-2920.16034] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 04/23/2022] [Accepted: 04/26/2022] [Indexed: 12/26/2022]
Abstract
Post‐translational modifications (PTMs) are important for protein function and regulate multiple cellular processes and secondary metabolites (SMs) in fungi. Aspergillus species belong to a genus renown for an abundance of bioactive secondary metabolites, many important as toxins, pharmaceuticals and in industrial production. The genes required for secondary metabolites are typically co‐localized in biosynthetic gene clusters (BGCs), which often localize in heterochromatic regions of genome and are ‘turned off’ under laboratory condition. Efforts have been made to ‘turn on’ these BGCs by genetic manipulation of histone modifications, which could convert the heterochromatic structure to euchromatin. Additionally, non‐histone PTMs also play critical roles in the regulation of secondary metabolism. In this review, we collate the known roles of epigenetic and PTMs on Aspergillus SM production. We also summarize the proteomics approaches and bioinformatics tools for PTM identification and prediction and provide future perspectives on the emerging roles of PTM on regulation of SM biosynthesis in Aspergillus and other fungi.
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Affiliation(s)
- Kunlong Yang
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, People's Republic of China.,Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, 53705, USA
| | - Jun Tian
- School of Life Science, Jiangsu Normal University, Xuzhou, 221116, Jiangsu Province, People's Republic of China
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, Wisconsin, 53705, USA
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10
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Pillay LC, Nekati L, Makhwitine PJ, Ndlovu SI. Epigenetic Activation of Silent Biosynthetic Gene Clusters in Endophytic Fungi Using Small Molecular Modifiers. Front Microbiol 2022; 13:815008. [PMID: 35237247 PMCID: PMC8882859 DOI: 10.3389/fmicb.2022.815008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 01/19/2022] [Indexed: 11/29/2022] Open
Abstract
The discovery of silent biosynthetic gene clusters (BGCs) in fungi provides unlimited prospects to harness the secondary metabolites encoded by gene clusters for various applications, including pharmaceuticals. Amplifying these prospects is the new interest in exploring fungi living in the extremes, such as those associated with plants (fungal endophytes). Fungal species in endosymbiosis relationship with plants are recognized as the future factories of clinically relevant agents since discovering that they can produce similar metabolites as their plant host. The endophytes produce these compounds in natural environments as a defense mechanism against pathogens that infect the plant host or as a strategy for mitigating competitors. The signaling cascades leading to the expression of silent biosynthetic gene clusters in the natural environment remain unknown. Lack of knowledge on regulatory circuits of biosynthetic gene clusters limits the ability to exploit them in the laboratory. They are often silent and require tailor-designed strategies for activation. Epigenetic modification using small molecular compounds that alter the chromatin network, leading to the changes in secondary metabolites profile, has achieved considerable success. This review aims to comprehensively analyze the secondary metabolite profiles expressed after treatment with various epigenetic modifiers. We first describe the regulatory circuits governing the expression of secondary metabolites in fungi. Following this, we provide a detailed review of the small molecular modifiers, their mechanism(s) of action, and the diverse chemistries resulting from epigenetic modification. We further show that genetic deletion or epigenetic inhibition of histone deacetylases does not always lead to the overexpression or induction of silent secondary metabolites. Instead, the response is more complex and often leads to differential expression of secondary metabolites. Finally, we propose using this strategy as an initial screening tool to dereplicate promising fungal species.
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11
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Saha P, Sarkar A, Sabnam N, Shirke MD, Mahesh HB, Nikhil A, Rajamani A, Gowda M, Roy-Barman S. Comparative analysis of secondary metabolite gene clusters in different strains of Magnaporthe oryzae. FEMS Microbiol Lett 2020; 368:6045507. [PMID: 33355334 DOI: 10.1093/femsle/fnaa216] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022] Open
Abstract
Rice blast caused by Magnaporthe oryzae continues to be a major constraint in rice production worldwide. Rice is one of the staple crops in India and rice blast causes huge economic losses. Interestingly, the Indian subcontinent is the centre for origin and diversity of rice as well as the Magnaporthe species complex. Secondary metabolites are known to play important role in pathogenesis and M. oryzae has high potential of genes involved in secondary metabolism but, unfortunately most of them remain uncharacterized. In the present study, we analysed the draft genome assemblies of M. oryzae strains isolated from different parts of India, for putative secondary metabolite key gene (SMKG) clusters encoding polyketide synthases, non-ribosomal peptide synthetases, diterpene cyclases and dimethylallyl tryptophan synthase. Based on the complete genome sequence of 70-15 strain and its previous reports of identified SMKGs, we have identified the key genes for the interrogated strains. Expression analysis of these genes amongst different strains indicates how they have evolved depending on the host and environmental conditions. To our knowledge, this study is first of its kind where the secondary metabolism genes and their role in functional adaptation were studied across several strains of M. oryzae.
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Affiliation(s)
- Pallabi Saha
- Department of Biotechnology, National Institute of Technology, Mahatma Gandhi Rd, A-zone, Durgapur, West Bengal-713209, India
| | - Atrayee Sarkar
- Department of Biotechnology, National Institute of Technology, Mahatma Gandhi Rd, A-zone, Durgapur, West Bengal-713209, India
| | - Nazmiara Sabnam
- Department of Biotechnology, National Institute of Technology, Mahatma Gandhi Rd, A-zone, Durgapur, West Bengal-713209, India.,Department of Life Sciences, Presidency University, 86/1 College street, Kolkata, West Bengal-700073, India
| | - Meghana D Shirke
- Centre for Functional Genomics and Bioinformatics, The University of Trans-Disciplinary Health Sciences and Technology, 74/2, Post Attur via Yelahanka, Jarakabande Kaval, Bengaluru-560064, India
| | - H B Mahesh
- Department of Genetics and Plant Breeding, College of Agriculture, V. C. Farm, Mandya, University of Agricultural Sciences, Bengaluru-560065, India
| | - Aman Nikhil
- Department of Biotechnology, National Institute of Technology, Mahatma Gandhi Rd, A-zone, Durgapur, West Bengal-713209, India
| | - Anantharamanan Rajamani
- Genome Analysis Laboratory, Rubber Research Institute of India, Kottayam, Kerala-686009, India
| | - Malali Gowda
- Centre for Functional Genomics and Bioinformatics, The University of Trans-Disciplinary Health Sciences and Technology, 74/2, Post Attur via Yelahanka, Jarakabande Kaval, Bengaluru-560064, India
| | - Subhankar Roy-Barman
- Department of Biotechnology, National Institute of Technology, Mahatma Gandhi Rd, A-zone, Durgapur, West Bengal-713209, India
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12
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Khan I, Xie WL, Yu YC, Sheng H, Xu Y, Wang JQ, Debnath SC, Xu JZ, Zheng DQ, Ding WJ, Wang PM. Heteroexpression of Aspergillus nidulans laeA in Marine-Derived Fungi Triggers Upregulation of Secondary Metabolite Biosynthetic Genes. Mar Drugs 2020; 18:md18120652. [PMID: 33352941 PMCID: PMC7766385 DOI: 10.3390/md18120652] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/04/2020] [Accepted: 12/15/2020] [Indexed: 11/26/2022] Open
Abstract
Fungi are a prospective resource of bioactive compounds, but conventional methods of drug discovery are not effective enough to fully explore their metabolic potential. This study aimed to develop an easily attainable method to elicit the metabolic potential of fungi using Aspergillus nidulans laeA as a transcription regulation tool. In this study, functional analysis of Aspergillus nidulans laeA (AnLaeA) and Aspergillus sp. Z5 laeA (Az5LaeA) was done in the fungus Aspergillus sp. Z5. Heterologous AnLaeA-and native Az5LaeA-overexpression exhibited similar phenotypic effects and caused an increase in production of a bioactive compound diorcinol in Aspergillus sp. Z5, which proved the conserved function of this global regulator. In particular, heteroexpression of AnLaeA showed a significant impact on the expression of velvet complex genes, diorcinol synthesis-related genes, and different transcription factors (TFs). Moreover, heteroexpression of AnLaeA influenced the whole genome gene expression of Aspergillus sp. Z5 and triggered the upregulation of many genes. Overall, these findings suggest that heteroexpression of AnLaeA in fungi serves as a simple and easy method to explore their metabolic potential. In relation to this, AnLaeA was overexpressed in the fungus Penicillium sp. LC1-4, which resulted in increased production of quinolactacin A.
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13
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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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14
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Frawley D, Bayram Ö. The pheromone response module, a mitogen-activated protein kinase pathway implicated in the regulation of fungal development, secondary metabolism and pathogenicity. Fungal Genet Biol 2020; 144:103469. [PMID: 32950720 DOI: 10.1016/j.fgb.2020.103469] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/05/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022]
Abstract
Mitogen-activated protein kinase (MAPK) pathways are highly conserved from yeast to human and are required for the regulation of a multitude of biological processes in eukaryotes. A pentameric MAPK pathway known as the Fus3 pheromone module was initially characterised in Saccharomyces cerevisiae and was shown to regulate cell fusion and sexual development. Individual orthologous pheromone module genes have since been found to be highly conserved in fungal genomes and have been shown to regulate a diverse array of cellular responses, such as cell growth, asexual and sexual development, secondary metabolite production and pathogenicity. However, information regarding the assembly and structure of orthologous pheromone modules, as well as the mechanisms of signalling and their biological significance is limited, specifically in filamentous fungal species. Recent studies have provided insight on the utilization of the pheromone module as a central signalling hub for the co-ordinated regulation of fungal development and secondary metabolite production. Various proteins of this pathway are also known to regulate reproduction and virulence in a range of plant pathogenic fungi. In this review, we discuss recent findings that help elucidate the structure of the pheromone module pathway in a myriad of fungal species and its implications in the control of fungal growth, development, secondary metabolism and pathogenicity.
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Affiliation(s)
- Dean Frawley
- Biology Department, Callan Building, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Özgür Bayram
- Biology Department, Callan Building, Maynooth University, Maynooth, Co. Kildare, Ireland.
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15
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Barrios-González J, Pérez-Sánchez A, Bibián ME. New knowledge about the biosynthesis of lovastatin and its production by fermentation of Aspergillus terreus. Appl Microbiol Biotechnol 2020; 104:8979-8998. [PMID: 32930839 DOI: 10.1007/s00253-020-10871-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 08/10/2020] [Accepted: 08/31/2020] [Indexed: 12/21/2022]
Abstract
Lovastatin, and its semisynthetic derivative simvastatine, has great medical and economic importance, besides great potential for other uses. In the last years, a deeper and more complex view of secondary metabolism regulation has emerged, with the incorporation of cluster-specific and global transcription factors, and their relation to signaling cascades, as well as the new level of epigenetic regulation. Recently, a new mechanism, which regulates lovastatin biosynthesis, at transcriptional level, has been discovered: reactive oxygen species (ROS) regulation; also new unexpected environmental stimuli have been identified, which induce the synthesis of lovastatin, like quorum sensing-type molecules and support stimuli. The present review describes this new panorama and uses this information, together with the knowledge on lovastatin biosynthesis and genomics, as the foundation to analyze literature on optimization of fermentation parameters and medium composition, and also to fully understand new strategies for strain genetic improvement. This new knowledge has been applied to the development of more effective culture media, with the addition of molecules like butyrolactone I, oxylipins, and spermidine, or with addition of ROS-generating molecules to increase internal ROS levels in the cell. It has also been applied to the development of new strategies to generate overproducing strains of Aspergillus terreus, including engineering of the cluster-specific transcription factor (lovE), global transcription factors like the ones implicated in ROS regulation (or even mitochondrial alternative respiration aox gen), or the global regulator LaeA. Moreover, there is potential to apply some of these findings to the development of novel unconventional production systems. KEY POINTS: • New findings in regulation of lovastatin biosynthesis, like ROS regulation. • Induction by unexpected stimuli: autoinducer molecules and support stimuli. • Recent reports on culture medium and process optimization from this stand point. • Applications to molecular genetic strain improvement methods and production systems.
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Affiliation(s)
- Javier Barrios-González
- Departamento de Biotecnología, Universidad Autónoma Metropolitana -Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340, Iztapalapa, Ciudad de México, Mexico.
| | - Ailed Pérez-Sánchez
- Departamento de Biotecnología, Universidad Autónoma Metropolitana -Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340, Iztapalapa, Ciudad de México, Mexico
| | - María Esmeralda Bibián
- Departamento de Biotecnología, Universidad Autónoma Metropolitana -Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340, Iztapalapa, Ciudad de México, Mexico
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16
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Shi JC, Shi WL, Zhou YR, Chen XL, Zhang YZ, Zhang X, Zhang WX, Song XY. The Putative Methyltransferase TlLAE1 Is Involved in the Regulation of Peptaibols Production in the Biocontrol Fungus Trichoderma longibrachiatum SMF2. Front Microbiol 2020; 11:1267. [PMID: 32612590 PMCID: PMC7307461 DOI: 10.3389/fmicb.2020.01267] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 05/18/2020] [Indexed: 11/30/2022] Open
Abstract
The biocontrol fungus Trichoderma longibrachiatum SMF2 secretes a large quantity of peptaibols that have been shown to have a range of biological activities and therefore great application values. However, the mechanism of the regulatory expression of peptaibols is still unclear. The putative methyltransferase LaeA/LAE1 is a global regulator involved in the biosynthesis of some secondary metabolites in filamentous fungi. In this study, we demonstrated that the ortholog of LaeA/LAE1 in the biocontrol fungus T. longibrachiatum SMF2, TlLAE1, plays an important role in the regulation of peptaibols production. Deletion of Tllae1 resulted in a slight negative impact on mycelial growth, and a significant defect in conidial production. Deletion of Tllae1 also compromised the production of peptaibols to a large degree. Further analyses indicated that this defect occurred at the transcriptional level of the two synthetases-encoding genes, tlx1 and tlx2, which are responsible for peptaibols production. By contrast, constitutive expression of Tllae1 in T. longibrachiatum SMF2 led to 2-fold increased peptaibols production, suggesting that this is a strategy to improve peptaibols production in Trichoderma fungi. These results demonstrate the important role of LAE1 in the regulation of peptaibols production in T. longibrachiatum SMF2.
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Affiliation(s)
- Jin-Chao Shi
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Wei-Ling Shi
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Yan-Rong Zhou
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiu-Lan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Yu-Zhong Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Xia Zhang
- Department of Molecular Biology, Qingdao Vland Biotech Inc., Qingdao, China
| | - Wei-Xin Zhang
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Qingdao, China
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17
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Abstract
Fungi are rich sources of secondary metabolites of pharmaceutical importance, such as antibiotics, antitumor agents, and immunosuppressants, as well as of harmful toxins. Secondary metabolites play important roles in the development and pathogenesis of fungi. LaeA is a global regulator of secondary metabolism and was originally reported in Aspergillus nidulans; however, its role in secondary metabolism in Magnaporthe oryzae has not yet been reported. Here, we investigated the role of a gene homologous to LAEA (loss of AflR expression) of Aspergillus spp. in Magnaporthe oryzae, named M. oryzaeLAEA (MoLAEA). Studies on MoLAEA overexpression and knockdown strains have suggested that this gene acts as a negative regulator of sporulation and melanin synthesis. However, it is not involved in the growth and pathogenesis of M. oryzae Transcriptomic data indicated that MoLAEA regulated genes involved in secondary metabolism. Interestingly, we observed (for the first time, to our knowledge) that this gene is involved in benzylpenicillin (penicillin G) synthesis in M. oryzae Overexpression of MoLAEA increased penicillin G production, whereas the silenced strain showed a complete absence of penicillin G compared to its presence in the wild type. We also observed that MoLaeA interacted with MoVeA, a velvet family protein involved in fungal development and secondary metabolism, in the nucleus. This study showed that though MoLAEA may not make any contribution in rice blast fungal pathogenesis, it regulates secondary metabolism in M. oryzae and thus can be further studied for identifying other new uncharacterized metabolites in this fungus.IMPORTANCEM. oryzae causes blast disease, the most serious disease of cultivated rice affecting global rice production. The genome of M. oryzae has been shown to have a number of genes involved in secondary metabolism, but most of them are uncharacterized. In fact, compared to studies of other filamentous fungi, hardly any work has been done on secondary metabolism in M. oryzae It is shown here (for the first time, to our knowledge) that penicillin G is being synthesized in M. oryzae and that MoLAEA is involved in this process. This is the first step in understanding the penicillin G biosynthesis pathway in M. oryzae This study also unraveled the details of how MoLaeA works by forming a nuclear complex with MoVeA in M. oryzae, thus indicating functional conservation of such a gene across filamentous fungi. All these findings open up avenues for more relevant investigations on the genetic regulation of secondary metabolism in M. oryzae.
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18
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Evaluation of DNA Methylation Changes by CRED-RA Analysis Following Prednisone Treatment of Endophyte, Fusarium oxysporum. Indian J Microbiol 2020; 60:254-258. [PMID: 32255859 DOI: 10.1007/s12088-020-00857-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 01/16/2020] [Indexed: 01/07/2023] Open
Abstract
Endophytes that represent a sub-set of plant resident microbes are a reservoir of bioactive metabolites. Many of the secondary metabolite biosynthetic gene clusters of endophytes are silent under axenic culture conditions. Epigenetic reprogramming of such cryptic pathways is possible by use of small molecule modulators like prednisone. Methylation changes induced by prednisone, a hypomethylating epigenetic modulator were studied in endophytic Fusarium oxysporum. CRED-RA analysis following exposure to non-cytotoxic dose (300 µM) revealed prednisone as effective in inducing non-methylation and semi-methylation pattern while inhibiting full-methylation of the genome. Effectiveness of prednisone as a DNA methyl transferase inhibitor can be explored in future to study alterations in secondary metabolite gene expression profile in endophytic F. oxysporum.
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19
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Lyu HN, Liu HW, Keller NP, Yin WB. Harnessing diverse transcriptional regulators for natural product discovery in fungi. Nat Prod Rep 2020; 37:6-16. [DOI: 10.1039/c8np00027a] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review covers diverse transcriptional regulators for the activation of secondary metabolism and novel natural product discovery in fungi.
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Affiliation(s)
- Hai-Ning Lyu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Hong-Wei Liu
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology and Bacteriology
- University of Wisconsin–Madison
- Madison
- USA
| | - Wen-Bing Yin
- State Key Laboratory of Mycology
- Institute of Microbiology
- Chinese Academy of Sciences
- Beijing
- China
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20
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van Leeuwe TM, Arentshorst M, Ernst T, Alazi E, Punt PJ, Ram AFJ. Efficient marker free CRISPR/Cas9 genome editing for functional analysis of gene families in filamentous fungi. Fungal Biol Biotechnol 2019; 6:13. [PMID: 31559019 PMCID: PMC6754632 DOI: 10.1186/s40694-019-0076-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND CRISPR/Cas9 mediated genome editing has expedited the way of constructing multiple gene alterations in filamentous fungi, whereas traditional methods are time-consuming and can be of mutagenic nature. These developments allow the study of large gene families that contain putatively redundant genes, such as the seven-membered family of crh-genes encoding putative glucan-chitin crosslinking enzymes involved in cell wall biosynthesis. RESULTS Here, we present a CRISPR/Cas9 system for Aspergillus niger using a non-integrative plasmid, containing a selection marker, a Cas9 and a sgRNA expression cassette. Combined with selection marker free knockout repair DNA fragments, a set of the seven single knockout strains was obtained through homology directed repair (HDR) with an average efficiency of 90%. Cas9-sgRNA plasmids could effectively be cured by removing selection pressure, allowing the use of the same selection marker in successive transformations. Moreover, we show that either two or even three separate Cas9-sgRNA plasmids combined with marker-free knockout repair DNA fragments can be used in a single transformation to obtain double or triple knockouts with 89% and 38% efficiency, respectively. By employing this technique, a seven-membered crh-gene family knockout strain was acquired in a few rounds of transformation; three times faster than integrative selection marker (pyrG) recycling transformations. An additional advantage of the use of marker-free gene editing is that negative effects of selection marker gene expression are evaded, as we observed in the case of disrupting virtually silent crh family members. CONCLUSIONS Our findings advocate the use of CRISPR/Cas9 to create multiple gene deletions in both a fast and reliable way, while simultaneously omitting possible locus-dependent-side-effects of poor auxotrophic marker expression.
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Affiliation(s)
- Tim M. van Leeuwe
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Mark Arentshorst
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Tim Ernst
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
| | - Ebru Alazi
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
- Present Address: Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Peter J. Punt
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
- Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Arthur F. J. Ram
- Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333 BE Leiden, The Netherlands
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21
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Reus E, Nielsen MR, Frandsen RJN. Metabolic and regulatory insights from the experimental horizontal gene transfer of the aurofusarin and bikaverin gene clusters to
Aspergillus nidulans. Mol Microbiol 2019; 112:1684-1700. [DOI: 10.1111/mmi.14376] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/18/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Elise Reus
- Department of Biotechnology and Bioengineering Technical University of Denmark Kongens Lyngby Denmark
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22
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Yu J, Han H, Zhang X, Ma C, Sun C, Che Q, Gu Q, Zhu T, Zhang G, Li D. Discovery of Two New Sorbicillinoids by Overexpression of the Global Regulator LaeA in a Marine-Derived Fungus Penicillium dipodomyis YJ-11. Mar Drugs 2019; 17:md17080446. [PMID: 31357680 PMCID: PMC6723206 DOI: 10.3390/md17080446] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 07/18/2019] [Accepted: 07/26/2019] [Indexed: 01/14/2023] Open
Abstract
Overexpression of the global regulator LaeA in a marine-derived fungal strain of Penicillium dipodomyis YJ-11 induced obvious morphological changes and metabolic variations. Further chemical investigation of the mutant strain afforded a series of sorbicillinoids including two new ones named 10,11-dihydrobislongiquinolide (1) and 10,11,16,17-tetrahydrobislongiquinolide (2), as well as four known analogues, bislongiquinolide (3), 16,17-dihydrobislongiquinolide (4), sohirnone A (5), and 2′,3′-dihydrosorbicillin (6). The results support that the global regulator LaeA is a useful tool in activating silent gene clusters in Penicillium strains to obtain previously undiscovered compounds.
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Affiliation(s)
- Jing Yu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Huan Han
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Xianyan Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Chuanteng Ma
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Chunxiao Sun
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Qian Che
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Qianqun Gu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
| | - Tianjiao Zhu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
| | - Guojian Zhang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China
| | - Dehai Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao 266003, China.
- Laboratory for Marine Drugs and Bioproducts, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266237, China.
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23
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Collemare J, Seidl MF. Chromatin-dependent regulation of secondary metabolite biosynthesis in fungi: is the picture complete? FEMS Microbiol Rev 2019; 43:591-607. [PMID: 31301226 PMCID: PMC8038932 DOI: 10.1093/femsre/fuz018] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 06/18/2019] [Indexed: 01/07/2023] Open
Abstract
Fungal secondary metabolites are small molecules that exhibit diverse biological activities exploited in medicine, industry and agriculture. Their biosynthesis is governed by co-expressed genes that often co-localize in gene clusters. Most of these secondary metabolite gene clusters are inactive under laboratory conditions, which is due to a tight transcriptional regulation. Modifications of chromatin, the complex of DNA and histone proteins influencing DNA accessibility, play an important role in this regulation. However, tinkering with well-characterised chemical and genetic modifications that affect chromatin alters the expression of only few biosynthetic gene clusters, and thus the regulation of the vast majority of biosynthetic pathways remains enigmatic. In the past, attempts to activate silent gene clusters in fungi mainly focused on histone acetylation and methylation, while in other eukaryotes many other post-translational modifications are involved in transcription regulation. Thus, how chromatin regulates the expression of gene clusters remains a largely unexplored research field. In this review, we argue that focusing on only few well-characterised chromatin modifications is significantly hampering our understanding of the chromatin-based regulation of biosynthetic gene clusters. Research on underexplored chromatin modifications and on the interplay between different modifications is timely to fully explore the largely untapped reservoir of fungal secondary metabolites.
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Affiliation(s)
| | - Michael F Seidl
- Corresponding author: Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands. E-mail: ; Present address: Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584 CH Utrecht, the Netherlands
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24
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Rahnama M, Maclean P, Fleetwood DJ, Johnson RD. The LaeA orthologue in Epichloë festucae is required for symbiotic interaction with Lolium perenne. Fungal Genet Biol 2019; 129:74-85. [PMID: 31071427 DOI: 10.1016/j.fgb.2019.05.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 05/02/2019] [Accepted: 05/02/2019] [Indexed: 10/26/2022]
Abstract
LaeA is a conserved global regulator of secondary metabolism and development in fungi. It is often required for successful pathogenic interactions. In this study, the laeA homologue in the fungal grass endophyte E. festucae was deleted and functionally characterised in vitro and its role in the mutualistic E. festucae interaction with Lolium perenne (perennial ryegrass) was determined. We showed that laeA in E. festucae is required for normal hyphal morphology, resistance to oxidative stress, and conidiation under nutrient-limited in vitro conditions. In planta studies revealed that laeA is expressed in a tissue-specific manner and is required to form a compatible plant interaction, with the majority of seedlings inoculated with a laeA deletion mutant either dying or being uninfected. In mature infected plants no difference was observed in the number or morphology of endophytic hyphae. However, the number of epiphyllous hyphae were greatly increased. Comparative transcriptomics analyses suggested roles for plant cell wall degradation, fungal cell wall composition, secondary metabolism and small-secreted proteins in Epichloë foliar symbiosis.
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Affiliation(s)
- M Rahnama
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand; School of Biological Sciences, University of Auckland, New Zealand
| | - P Maclean
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand
| | - D J Fleetwood
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand; Biotelliga Ltd, Auckland, New Zealand.
| | - R D Johnson
- AgResearch, Grasslands Research Centre, Palmerston North, New Zealand.
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25
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Mane RS, Paarakh PM, Vedamurthy AB. Brief Review on Fungal Endophytes. INTERNATIONAL JOURNAL OF SECONDARY METABOLITE 2018. [DOI: 10.21448/ijsm.482798] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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26
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Ramesha K, Mohana NC, Nuthan B, Rakshith D, Satish S. Epigenetic modulations of mycoendophytes for novel bioactive molecules. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2018. [DOI: 10.1016/j.bcab.2018.09.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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27
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Massonnet M, Morales-Cruz A, Minio A, Figueroa-Balderas R, Lawrence DP, Travadon R, Rolshausen PE, Baumgartner K, Cantu D. Whole-Genome Resequencing and Pan-Transcriptome Reconstruction Highlight the Impact of Genomic Structural Variation on Secondary Metabolite Gene Clusters in the Grapevine Esca Pathogen Phaeoacremonium minimum. Front Microbiol 2018; 9:1784. [PMID: 30150972 PMCID: PMC6099105 DOI: 10.3389/fmicb.2018.01784] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 07/16/2018] [Indexed: 12/30/2022] Open
Abstract
The Ascomycete fungus Phaeoacremonium minimum is one of the primary causal agents of Esca, a widespread and damaging grapevine trunk disease. Variation in virulence among Pm. minimum isolates has been reported, but the underlying genetic basis of the phenotypic variability remains unknown. The goal of this study was to characterize intraspecific genetic diversity and explore its potential impact on virulence functions associated with secondary metabolism, cellular transport, and cell wall decomposition. We generated a chromosome-scale genome assembly, using single molecule real-time sequencing, and resequenced the genomes and transcriptomes of multiple isolates to identify sequence and structural polymorphisms. Numerous insertion and deletion events were found for a total of about 1 Mbp in each isolate. Structural variation in this extremely gene dense genome frequently caused presence/absence polymorphisms of multiple adjacent genes, mostly belonging to biosynthetic clusters associated with secondary metabolism. Because of the observed intraspecific diversity in gene content due to structural variation we concluded that a transcriptome reference developed from a single isolate is insufficient to represent the virulence factor repertoire of the species. We therefore compiled a pan-transcriptome reference of Pm. minimum comprising a non-redundant set of 15,245 protein-coding sequences. Using naturally infected field samples expressing Esca symptoms, we demonstrated that mapping of meta-transcriptomics data on a multi-species reference that included the Pm. minimum pan-transcriptome allows the profiling of an expanded set of virulence factors, including variable genes associated with secondary metabolism and cellular transport.
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Affiliation(s)
- Mélanie Massonnet
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | - Abraham Morales-Cruz
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | - Andrea Minio
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | - Rosa Figueroa-Balderas
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | - Daniel P. Lawrence
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| | - Renaud Travadon
- Department of Plant Pathology, University of California, Davis, Davis, CA, United States
| | - Philippe E. Rolshausen
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Kendra Baumgartner
- Crops Pathology and Genetics Research Unit, Agricultural Research Service, United States Department of Agriculture, Davis, CA, United States
| | - Dario Cantu
- Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
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28
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Yao G, Yue Y, Fu Y, Fang Z, Xu Z, Ma G, Wang S. Exploration of the Regulatory Mechanism of Secondary Metabolism by Comparative Transcriptomics in Aspergillus flavus. Front Microbiol 2018; 9:1568. [PMID: 30131770 PMCID: PMC6090018 DOI: 10.3389/fmicb.2018.01568] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 06/25/2018] [Indexed: 12/31/2022] Open
Abstract
Mycotoxins cause a huge threaten to agriculture, food safety, and human and animal life. Among them, aflatoxins (AFs) have always been considered the most potent carcinogens, and filamentous fungi from Aspergillus genus are their major producers, especially A. flavus. Although the biosynthesis path of these chemicals had been well-identified, the regulatory mechanisms controlling expression of AF gene cluster were poorly understood. In this report, genome-wide transcriptome profiles of A. flavus from AF conducing [yeast sucrose media (YES)] and non-conducing [yeast peptone media (YEP)] conditions were compared by using deep RNA sequencing (RNA-seq), and the results revealed that AF biosynthesis pathway and biosynthesis of amino acids were significantly upregulated in YES vs. YEP. Further, a novel LaeA-like methyltransferase AFLA_121330 (Lael1) was identified for the first time, to play a specific role in the regulation of AF biosynthesis. Contrary to LaeA, which gene deletion reduced the level, lael1 deletion resulted in a significant increase in AF production. Further, co-expression network analysis revealed that mitochondrial pyruvate transport and signal peptide processing were potentially involved in AF synthesis for the first time, as well as biological processes of ribosome, branched-chain amino acid biosynthetic process and translation were co-regulated by AfRafA and AfStuA. To sum up, our analyses could provide novel insights into the molecular mechanism for controlling the AF and other secondary metabolite synthesis, adding novel targets for plant breeding and making fungicides.
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Affiliation(s)
- Guangshan Yao
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuewei Yue
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yishi Fu
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhou Fang
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Zhangling Xu
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Genli Ma
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shihua Wang
- Fujian Key Laboratory of Pathogenic Fungi and Mycotoxins, Key Laboratory of Biopesticide and Chemical Biology of Ministry of Education, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
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Chettri P, Dupont PY, Bradshaw RE. Chromatin-level regulation of the fragmented dothistromin gene cluster in the forest pathogen Dothistroma septosporum. Mol Microbiol 2018; 107:508-522. [DOI: 10.1111/mmi.13898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/10/2017] [Accepted: 12/11/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Pranav Chettri
- Bio-Protection Research Centre, Institute of Fundamental Sciences; Massey University; Palmerston North New Zealand
| | - Pierre-Yves Dupont
- Bio-Protection Research Centre, Institute of Fundamental Sciences; Massey University; Palmerston North New Zealand
| | - Rosie E. Bradshaw
- Bio-Protection Research Centre, Institute of Fundamental Sciences; Massey University; Palmerston North New Zealand
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Regulin A, Kempken F. Fungal genotype determines survival of Drosophila melanogaster when competing with Aspergillus nidulans. PLoS One 2018; 13:e0190543. [PMID: 29293643 PMCID: PMC5749846 DOI: 10.1371/journal.pone.0190543] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 12/15/2017] [Indexed: 01/07/2023] Open
Abstract
Fungi produce an astonishing variety of secondary metabolites, some of which belong to the most toxic compounds in the living world. Several fungal metabolites have anti-insecticidal properties which may yield advantages to the fungus in competition with insects for exploitation of environmental resources. Using the Drosophila melanogaster/Aspergillus nidulans ecological model system to assess secondary metabolite mutant genotypes, we find a major role for the veA allele in insect/fungal confrontations that exceeds the influence of other factors such as LaeA. VeA along with LaeA is a member of a transcriptional complex governing secondary metabolism in A. nidulans. However, historically a mutant veA allele, veA1 reduced in secondary metabolite output, has been used in many studies of this model organism. To test the significance of this allele in our system, Aspergillus nidulans veA wild type, veA1, ΔveA and ΔlaeA were evaluated in confrontation assays to analyze egg laying activity, and the survival rate of larvae. The veA1 genetic background led to a significant increase of larval survival. Adult flies were observed almost exclusively on veA1, ΔveA or ΔlaeA genetic backgrounds, suggesting a role for the velvet complex in insect/fungal interactions. This effect was most profound using the veA1 mutant. Hence, larval survival in confrontations is highly affected by the fungal genotype.
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Affiliation(s)
- Annika Regulin
- Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität, Kiel, Germany
| | - Frank Kempken
- Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität, Kiel, Germany
- * E-mail:
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31
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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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32
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Wang B, Lv Y, Li X, Lin Y, Deng H, Pan L. Profiling of secondary metabolite gene clusters regulated by LaeA in Aspergillus niger FGSC A1279 based on genome sequencing and transcriptome analysis. Res Microbiol 2017; 169:67-77. [PMID: 29054463 DOI: 10.1016/j.resmic.2017.10.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 10/07/2017] [Accepted: 10/11/2017] [Indexed: 01/31/2023]
Abstract
The global regulator LaeA controls the production of many fungal secondary metabolites, possibly via chromatin remodeling. Here we aimed to survey the secondary metabolite profile regulated by LaeA in Aspergillus niger FGSC A1279 by genome sequencing and comparative transcriptomics between the laeA deletion (ΔlaeA) and overexpressing (OE-laeA) mutants. Genome sequencing revealed four putative polyketide synthase genes specific to FGSC A1279, suggesting that the corresponding polyketide compounds might be unique to FGSC A1279. RNA-seq data revealed 281 putative secondary metabolite genes upregulated in the OE-laeA mutants, including 22 secondary metabolite backbone genes. LC-MS chemical profiling illustrated that many secondary metabolites were produced in OE-laeA mutants compared to wild type and ΔlaeA mutants, providing potential resources for drug discovery. KEGG analysis annotated 16 secondary metabolite clusters putatively linked to metabolic pathways. Furthermore, 34 of 61 Zn2Cys6 transcription factors located in secondary metabolite clusters were differentially expressed between ΔlaeA and OE-laeA mutants. Three secondary metabolite clusters (cluster 18, 30 and 33) containing Zn2Cys6 transcription factors that were upregulated in OE-laeA mutants were putatively linked to KEGG pathways, suggesting that Zn2Cys6 transcription factors might play an important role in synthesizing secondary metabolites regulated by LaeA. Taken together, LaeA dramatically influences the secondary metabolite profile in FGSC A1279.
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Affiliation(s)
- Bin Wang
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
| | - Yangyong Lv
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Xuejie Li
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Yiying Lin
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China.
| | - Hai Deng
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland, UK.
| | - Li Pan
- School of Biology and Biological Engineering, South China University of Technology, No. 382 Waihuan East Rd, Guangzhou Higher Education Mega Center, Guangzhou, 510006, China; Guangdong Provincial Key Laboratory of Fermentation and Enzyme Engineering, South China University of Technology, Guangzhou, 510006, China.
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33
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Identification and characterization of genes involved in kojic acid biosynthesis in Aspergillus flavus. ANN MICROBIOL 2017. [DOI: 10.1007/s13213-017-1297-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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34
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Zhao Y, Ding J, Yuan W, Huang J, Huang W, Wang Y, Zheng W. Production of a fungal furocoumarin by a polyketide synthase gene cluster confers the chemo-resistance of Neurospora crassa to the predation by fungivorous arthropods. Environ Microbiol 2017; 19:3920-3929. [PMID: 28485098 DOI: 10.1111/1462-2920.13791] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 12/25/2022]
Abstract
The formation of sexual fruiting bodies and production of polyketides are believed to be the most important strategies for fungal survival in environmental insults. In Neurospora crassa, the backbone gene of polyketide synthase gene cluster 6 (pks-6), which is expressed at lower level under vegetative growth, is highly expressed during perithecia development. Intriguingly, deletion of pks-6 does not affect perithecia maturation. How the expression of pks-6 correlates with fungal sexual development remains to be established. Here, we showed that overexpression of pks-6 results in an enhanced production of an insecticidal furocoumarin (neurosporin A). Deletion of pks-6, however, abolished neurosporin A biosynthesis. Moreover, the content of neurosporin A negatively associates with the food preference of fungivores, where the pks-6 knockout strain is more prone to be grazed by collembolans Sinella curviseta. Additionally, during vegetative growth, confrontation with Drosophila melanogaster also results in an enhanced expression of pks-6 and production of neurosporin A. Thus, high expression of pks-6 positively interrelates with the chemo-resistance of N. crassa to arthropod predation. Our findings suggest that pks-6 confers the production of insecticidal neurosporin A counteracting the feeding attack by arthropods during sexual development of N. crassa.
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Affiliation(s)
- Yanxia Zhao
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jianing Ding
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Weihua Yuan
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Jinjin Huang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Wenxiu Huang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Yan Wang
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
| | - Weifa Zheng
- Key Laboratory for Biotechnology on Medicinal Plants of Jiangsu Province, School of Life Sciences, Jiangsu Normal University, Xuzhou, 221116, China
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Differential Control of Asexual Development and Sterigmatocystin Biosynthesis by a Novel Regulator in Aspergillus nidulans. Sci Rep 2017; 7:46340. [PMID: 28422127 PMCID: PMC5396049 DOI: 10.1038/srep46340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 03/15/2017] [Indexed: 11/08/2022] Open
Abstract
The filamentous fungus Aspergillus nidulans primarily reproduces by forming asexual spores called conidia and produces the mycotoxin sterigmatocystin (ST), the penultimate precursor of aflatoxins. It has been known that asexual development and ST production are tightly co-regulated by various regulatory inputs. Here, we report that the novel regulator AslA with a C2H2 domain oppositely regulates development and ST biosynthesis. Nullifying aslA resulted in defective conidiation and reduced expression of brlA encoding a key activator of asexual development, which indicates that AslA functions as an upstream activator of brlA expression. aslA deletion additionally caused enhanced ST production and expression of aflR encoding a transcriptional activator for ST biosynthetic genes, suggesting that AslA functions as an upstream negative regulator of aflR. Cellular and molecular studies showed that AslA has a trans-activation domain and is localized in the nuclei of vegetative and developing cells but not in spores, indicating that AslA is likely a transcription factor. Introduction of the aslA homologs from distantly-related aspergilli complemented the defects caused by aslA null mutation in A. nidulans, implying a functional conservancy of AslA. We propose that AslA is a novel regulator that may act at the split control point of the developmental and metabolic pathways.
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Janevska S, Arndt B, Niehaus EM, Burkhardt I, Rösler SM, Brock NL, Humpf HU, Dickschat JS, Tudzynski B. Gibepyrone Biosynthesis in the Rice Pathogen Fusarium fujikuroi Is Facilitated by a Small Polyketide Synthase Gene Cluster. J Biol Chem 2016; 291:27403-27420. [PMID: 27856636 PMCID: PMC5207165 DOI: 10.1074/jbc.m116.753053] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/14/2016] [Indexed: 11/06/2022] Open
Abstract
The 2H-pyran-2-one gibepyrone A and its oxidized derivatives gibepyrones B-F have been isolated from the rice pathogenic fungus Fusarium fujikuroi already more than 20 years ago. However, these products have not been linked to the respective biosynthetic genes, and therefore, their biosynthesis has not yet been analyzed on a molecular level. Feeding experiments with isotopically labeled precursors clearly supported a polyketide origin for the formal monoterpenoid gibepyrone A, whereas the terpenoid pathway could be excluded. Targeted gene deletion verified that the F. fujikuroi polyketide synthase PKS13, designated Gpy1, is responsible for gibepyrone A biosynthesis. Next to Gpy1, the ATP-binding cassette transporter Gpy2 is encoded by the gibepyrone gene cluster. Gpy2 was shown to have only a minor impact on the actual efflux of gibepyrone A out of the cell. Instead, we obtained evidence that Gpy2 is involved in gene regulation as it represses GPY1 gene expression. Thus, GPY1 was up-regulated and gibepyrone A production was enhanced both extra- and intracellularly in Δgpy2 mutants. Furthermore, expression of GPY genes is strictly repressed by members of the fungus-specific velvet complex, Vel1, Vel2, and Lae1, whereas Sge1, a major regulator of secondary metabolism in F. fujikuroi, affects gibepyrone biosynthesis in a positive manner. The gibepyrone A derivatives gibepyrones B and D were shown to be produced by cluster-independent P450 monooxygenases, probably to protect the fungus from the toxic product. In contrast, the formation of gibepyrones E and F from gibepyrone A is a spontaneous process and independent of enzymatic activity.
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Affiliation(s)
- Slavica Janevska
- From the Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, D-48143 Münster
| | - Birgit Arndt
- the Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 45, D-48149 Münster, and
| | - Eva-Maria Niehaus
- From the Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, D-48143 Münster
| | - Immo Burkhardt
- the Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
| | - Sarah M Rösler
- From the Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, D-48143 Münster
- the Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 45, D-48149 Münster, and
| | - Nelson L Brock
- the Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
| | - Hans-Ulrich Humpf
- the Institut für Lebensmittelchemie, Westfälische Wilhelms-Universität Münster, Corrensstrasse 45, D-48149 Münster, and
| | - Jeroen S Dickschat
- the Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, D-53121 Bonn, Germany
| | - Bettina Tudzynski
- From the Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Schlossplatz 8, D-48143 Münster,
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Identification of a Classical Mutant in the Industrial Host Aspergillus niger by Systems Genetics: LaeA Is Required for Citric Acid Production and Regulates the Formation of Some Secondary Metabolites. G3-GENES GENOMES GENETICS 2015; 6:193-204. [PMID: 26566947 PMCID: PMC4704718 DOI: 10.1534/g3.115.024067] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The asexual filamentous fungus Aspergillus niger is an important industrial cell factory for citric acid production. In this study, we genetically characterized a UV-generated A. niger mutant that was originally isolated as a nonacidifying mutant, which is a desirable trait for industrial enzyme production. Physiological analysis showed that this mutant did not secrete large amounts of citric acid and oxalic acid, thus explaining the nonacidifying phenotype. As traditional complementation approaches to characterize the mutant genotype were unsuccessful, we used bulk segregant analysis in combination with high-throughput genome sequencing to identify the mutation responsible for the nonacidifying phenotype. Since A. niger has no sexual cycle, parasexual genetics was used to generate haploid segregants derived from diploids by loss of whole chromosomes. We found that the nonacidifying phenotype was caused by a point mutation in the laeA gene. LaeA encodes a putative methyltransferase-domain protein, which we show here to be required for citric acid production in an A. niger lab strain (N402) and in other citric acid production strains. The unexpected link between LaeA and citric acid production could provide new insights into the transcriptional control mechanisms related to citric acid production in A. niger. Interestingly, the secondary metabolite profile of a ΔlaeA strain differed from the wild-type strain, showing both decreased and increased metabolite levels, indicating that LaeA is also involved in regulating the production of secondary metabolites. Finally, we show that our systems genetics approach is a powerful tool to identify trait mutations.
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38
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Deepika VB, Murali TS, Satyamoorthy K. Modulation of genetic clusters for synthesis of bioactive molecules in fungal endophytes: A review. Microbiol Res 2015; 182:125-40. [PMID: 26686621 DOI: 10.1016/j.micres.2015.10.009] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 10/21/2015] [Accepted: 10/26/2015] [Indexed: 11/26/2022]
Abstract
Novel drugs with unique and targeted mode of action are very much need of the hour to treat and manage severe multidrug infections and other life-threatening complications. Though natural molecules have proved to be effective and environmentally safe, the relative paucity of discovery of new drugs has forced us to lean towards synthetic chemistry for developing novel drug molecules. Plants and microbes are the major resources that we rely upon in our pursuit towards discovery of novel compounds of pharmacological importance with less toxicity. Endophytes, an eclectic group of microbes having the potential to chemically bridge the gap between plants and microbes, have attracted the most attention due to their relatively high metabolic versatility. Since continuous large scale supply of major metabolites from microfungi and especially endophytes is severely impeded by the phenomenon of attenuation in axenic cultures, the major challenge is to understand the regulatory mechanisms in operation that drive the expression of metabolic gene clusters of pharmaceutical importance. This review is focused on the major regulatory elements that operate in filamentous fungi and various combinatorial multi-disciplinary approaches involving bioinformatics, molecular biology, and metabolomics that could aid in large scale synthesis of important lead molecules.
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Affiliation(s)
- V B Deepika
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal 576104, India
| | - T S Murali
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal 576104, India.
| | - K Satyamoorthy
- Division of Biotechnology, School of Life Sciences, Manipal University, Manipal 576104, India
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Wang H, Lei Y, Yan L, Cheng K, Dai X, Wan L, Guo W, Cheng L, Liao B. Deep sequencing analysis of transcriptomes in Aspergillus flavus in response to resveratrol. BMC Microbiol 2015; 15:182. [PMID: 26420172 PMCID: PMC4589122 DOI: 10.1186/s12866-015-0513-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 06/23/2015] [Indexed: 12/19/2022] Open
Abstract
Background Resveratrol has been reported as a natural phytoalexin that inhibits infection or the growth of certain fungi including Aspergillus flavus. Our previous research revealed that aflatoxin production in A. flavus was reduced in medium with resveratrol. To understand the molecular mechanism of the A. flavus response to resveratrol treatment, the high-throughput paired-end RNA-Seq was applied to analyze the transcriptomic profiles of A. flavus. Results In total, 366 and 87 genes of A. flavus were significantly up- and down- regulated, respectively, when the fungus was treated with resveratrol. Gene Ontology (GO) functional enrichment analysis revealed that 48 significantly differentially expressed genes were involved in 6 different terms. Most genes in the aflatoxin biosynthetic pathway genes cluster (#54) did not show a significant change when A. flavus was treated with resveratrol, but 23 of the 30 genes in the #54 cluster were down-regulated. The transcription of aflA and aflB was significantly suppressed under resveratrol treatment, resulting in an insufficient amount of the starter unit hexanoate for aflatoxin biosynthesis. In addition, resveratrol significantly increased the activity of antioxidative enzymes that destroy radicals, leading to decreased aflatoxin production. Moreover, stuA, fluG, flbC, and others genes involved in mycelial and conidial development were down-regulated, which disrupted the cell’s orderly differentiation and blocked conidia formation and mycelia development. The transcripts of laeA and veA were slightly inhibited by resveratrol, which may partly decrease aflatoxin production and depress conidia formation. Conclusions Resveratrol can affect the expression of A. flavus genes that are related to developmental and secondary metabolic processes, resulting in decreased aflatoxin production and conidia formation and could also cause abnormal mycelia development. These results provide insight into the transcriptome of A. flavus in response to resveratrol and a new clew for further study in regulation of aflatoxin biosynthesis in A. flavus. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0513-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Houmiao Wang
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Yong Lei
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Liying Yan
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Ke Cheng
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Xiaofeng Dai
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Liyun Wan
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Wei Guo
- Institute of Agro-Products Processing Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Liangqiang Cheng
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
| | - Boshou Liao
- Key Laboratory of Oil Crop Biology of the Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, China. .,Chinese Academy of Agricultural Sciences-International Crop Research Institute for the Semi-Arid Tropics Joint Laboratory for Groundnut Aflatoxin Management, Wuhan, 430062, China.
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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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Calvo AM, Cary JW. Association of fungal secondary metabolism and sclerotial biology. Front Microbiol 2015; 6:62. [PMID: 25762985 PMCID: PMC4329819 DOI: 10.3389/fmicb.2015.00062] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 01/18/2015] [Indexed: 11/13/2022] Open
Abstract
Fungal secondary metabolism and morphological development have been shown to be intimately associated at the genetic level. Much of the literature has focused on the co-regulation of secondary metabolite production (e.g., sterigmatocystin and aflatoxin in Aspergillus nidulans and Aspergillus flavus, respectively) with conidiation or formation of sexual fruiting bodies. However, many of these genetic links also control sclerotial production. Sclerotia are resistant structures produced by a number of fungal genera. They also represent the principal source of primary inoculum for some phytopathogenic fungi. In nature, higher plants often concentrate secondary metabolites in reproductive structures as a means of defense against herbivores and insects. By analogy, fungi also sequester a number of secondary metabolites in sclerotia that act as a chemical defense system against fungivorous predators. These include antiinsectant compounds such as tetramic acids, indole diterpenoids, pyridones, and diketopiperazines. This chapter will focus on the molecular mechanisms governing production of secondary metabolites and the role they play in sclerotial development and fungal ecology, with particular emphasis on Aspergillus species. The global regulatory proteins VeA and LaeA, components of the velvet nuclear protein complex, serve as virulence factors and control both development and secondary metabolite production in many Aspergillus species. We will discuss a number of VeA- and LaeA-regulated secondary metabolic gene clusters in A. flavus that are postulated to be involved in sclerotial morphogenesis and chemical defense. The presence of multiple regulatory factors that control secondary metabolism and sclerotial formation suggests that fungi have evolved these complex regulatory mechanisms as a means to rapidly adapt chemical responses to protect sclerotia from predators, competitors and other environmental stressors.
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Affiliation(s)
- Ana M Calvo
- Department of Biological Sciences, Northern Illinois University DeKalb, IL, USA
| | - Jeffrey W Cary
- Southern Regional Research Center, United States Department of Agriculture - Agricultural Research Service New Orleans, LA, USA
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Epigenetics of Fungal Secondary Metabolism Related Genes. Fungal Biol 2015. [DOI: 10.1007/978-1-4939-2531-5_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Putri DA, Radjasa OK, Pringgenies D. Effectiveness of Marine Fungal Symbiont Isolated from Soft Coral Sinularia sp. from Panjang Island as Antifungal. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.proenv.2015.01.051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Karimi Aghcheh R, Németh Z, Atanasova L, Fekete E, Paholcsek M, Sándor E, Aquino B, Druzhinina IS, Karaffa L, Kubicek CP. The VELVET A orthologue VEL1 of Trichoderma reesei regulates fungal development and is essential for cellulase gene expression. PLoS One 2014; 9:e112799. [PMID: 25386652 PMCID: PMC4227869 DOI: 10.1371/journal.pone.0112799] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 10/15/2014] [Indexed: 11/25/2022] Open
Abstract
Trichoderma reesei is the industrial producer of cellulases and hemicellulases for biorefinery processes. Their expression is obligatorily dependent on the function of the protein methyltransferase LAE1. The Aspergillus nidulans orthologue of LAE1 - LaeA - is part of the VELVET protein complex consisting of LaeA, VeA and VelB that regulates secondary metabolism and sexual as well as asexual reproduction. Here we have therefore investigated the function of VEL1, the T. reesei orthologue of A. nidulans VeA. Deletion of the T. reesei vel1 locus causes a complete and light-independent loss of conidiation, and impairs formation of perithecia. Deletion of vel1 also alters hyphal morphology towards hyperbranching and formation of thicker filaments, and with consequently reduced growth rates. Growth on lactose as a sole carbon source, however, is even more strongly reduced and growth on cellulose as a sole carbon source eliminated. Consistent with these findings, deletion of vel1 completely impaired the expression of cellulases, xylanases and the cellulase regulator XYR1 on lactose as a cellulase inducing carbon source, but also in resting mycelia with sophorose as inducer. Our data show that in T. reesei VEL1 controls sexual and asexual development, and this effect is independent of light. VEL1 is also essential for cellulase gene expression, which is consistent with the assumption that their regulation by LAE1 occurs by the VELVET complex.
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Affiliation(s)
- Razieh Karimi Aghcheh
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria
| | - Zoltán Németh
- Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary
| | - Lea Atanasova
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary
| | - Melinda Paholcsek
- Department of Human Genetics, Faculty of Medicine, University of Debrecen, H-4032 Debrecen, Hungary
| | - Erzsébet Sándor
- Faculty of Agricultural and Food Science and Environmental Management, Institute of Food Science, H-4032 Debrecen, Hungary
| | - Benigno Aquino
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria
| | - Irina S. Druzhinina
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria
- Austrian Center of Industrial Biotechnology, c/o Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Sciences and Technology, University of Debrecen, H-4032 Debrecen, Hungary
| | - Christian P. Kubicek
- Institute of Chemical Engineering, Research Division Biotechnology and Microbiology, Microbiology Group, Vienna University of Technology, 1060 Vienna, Austria
- Austrian Center of Industrial Biotechnology, 8010 Graz, Austria
- * E-mail:
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Karácsony Z, Gácser A, Vágvölgyi C, Scazzocchio C, Hamari Z. A dually located multi-HMG-box protein of Aspergillus nidulans has a crucial role in conidial and ascospore germination. Mol Microbiol 2014; 94:383-402. [PMID: 25156107 DOI: 10.1111/mmi.12772] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2014] [Indexed: 11/28/2022]
Abstract
Seven HMG-box proteins of Aspergillus nidulans have been identified in the genomic databases. Three of these have the characteristics of non-specific DNA-binding proteins. One of these, AN1267 (HmbB), comprises one canonical HMG-box in its C-terminus and upstream of the canonical box two structurally related boxes, to be called Shadow-HMG-boxes. This protein defines, together with the Podospora anserina mtHMG1, a clade of proteins present in the Pezizomycotina, with orthologues in some of the Taphrinomycotina. HmbB localizes primarily to the mitochondria but occasionally in nuclei. The deletion of the cognate gene results in a number of pleiotropic effects, including those on hyphal morphology, sensitivity to oxidative stress, absence of sterigmatocystin production and changes in the profile of conidial metabolites. The most striking phenotype of deletion strains is a dramatic decrease in conidial and ascospore viability. We show that this is most likely due to the protein being essential to maintain mitochondrial DNA in spores.
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Affiliation(s)
- Zoltán Karácsony
- University of Szeged Faculty of Sciences and Informatics, Department of Microbiology, H-6726, Szeged, Közép fasor 52, Hungary
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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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Albinsson ME, Negri AP, Blackburn SI, Bolch CJS. Bacterial community affects toxin production by Gymnodinium catenatum. PLoS One 2014; 9:e104623. [PMID: 25117053 PMCID: PMC4130555 DOI: 10.1371/journal.pone.0104623] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 07/15/2014] [Indexed: 11/30/2022] Open
Abstract
The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134–197 fmol STX cell−1) was similar to the parent cultures (169–206 fmol STX cell−1), however cultures grown with single bacterial types contained less toxin (134–146 fmol STX cell−1) than offspring or parent cultures grown with more complex mixed bacterial communities (152–176 fmol STX cell−1). Specific toxin production rate (fmol STX day−1) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell−1 day−1) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX production of dinoflagellates. In G. catenatum the mechanism appears likely to be due to bacterial effects on dinoflagellate physiology rather than bacterial biotransformation of PST toxins.
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Affiliation(s)
- Maria E. Albinsson
- National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Launceston, Tasmania, Australia
- Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, Hobart, Tasmania, Australia
- * E-mail:
| | - Andrew P. Negri
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Susan I. Blackburn
- Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, Hobart, Tasmania, Australia
| | - Christopher J. S. Bolch
- National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Launceston, Tasmania, Australia
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Genilloud O. The re-emerging role of microbial natural products in antibiotic discovery. Antonie Van Leeuwenhoek 2014; 106:173-88. [PMID: 24923558 DOI: 10.1007/s10482-014-0204-6] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/23/2014] [Indexed: 11/28/2022]
Abstract
New classes of antibacterial compounds are urgently needed to respond to the high frequency of occurrence of resistances to all major classes of known antibiotics. Microbial natural products have been for decades one of the most successful sources of drugs to treat infectious diseases but today, the emerging unmet clinical need poses completely new challenges to the discovery of novel candidates with the desired properties to be developed as antibiotics. While natural products discovery programs have been gradually abandoned by the big pharma, smaller biotechnology companies and research organizations are taking over the lead in the discovery of novel antibacterials. Recent years have seen new approaches and technologies being developed and integrated in a multidisciplinary effort to further exploit microbial resources and their biosynthetic potential as an untapped source of novel molecules. New strategies to isolate novel species thought to be uncultivable, and synthetic biology approaches ranging from genome mining of microbial strains for cryptic biosynthetic pathways to their heterologous expression have been emerging in combination with high throughput sequencing platforms, integrated bioinformatic analysis, and on-site analytical detection and dereplication tools for novel compounds. These different innovative approaches are defining a completely new framework that is setting the bases for the future discovery of novel chemical scaffolds that should foster a renewed interest in the identification of novel classes of natural product antibiotics from the microbial world.
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Affiliation(s)
- Olga Genilloud
- Fundación MEDINA, Avda Conocimiento 3, Parque Tecnológico Ciencias de la Salud, 18016, Granada, Spain,
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