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Liu J, Guo X, Guo X, Zhong B, Wang T, Liu D, Jin H, Ren J, Liu Z, Gao J, Li SM, Fan A, Lin W. Concise Biosynthesis of Tropone-Containing Spiromaterpenes by a Sesquiterpene Cyclase and a Multifunctional P450 from a Deep-Sea-Derived Spiromastix sp. Fungus. JOURNAL OF NATURAL PRODUCTS 2022; 85:2723-2730. [PMID: 36414326 DOI: 10.1021/acs.jnatprod.2c00614] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Spiromaterpenes are a group of rare tropone-containing sesquiterpenes with antineuroinflammatory activity. Herein, we elucidate their biosynthetic pathway in a deep-sea-derived Spiromastix sp. fungus by heterologous expression, biochemical characterization, and incubation experiments. The sesquiterpene cyclase SptA was first characterized to catalyze the production of guaia-1(5),6-diene, and a multifunctional cytochrome P450 catalyzed the tropone ring formation. These results provide important clues for the rational mining of bioactive guaiane-type sesquiterpenes and expand the repertoire of P450 activities to synthesize unique building blocks of natural products.
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Affiliation(s)
- Jie Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Xiang Guo
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Xingchen Guo
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Boyuan Zhong
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Tao Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Dong Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Hongwei Jin
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Jinwei Ren
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Zihe Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100013, People's Republic of China
| | - Jiangtao Gao
- Fujian Provincial Key Laboratory of Plant Functional Biology, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, People's Republic of China
| | - Shu-Ming Li
- Institut für Pharmazeutische Biologie und Biotechnologie, Fachbereich Pharmazie, Philipps-Universität Marburg, 35037 Marburg, Germany
| | - Aili Fan
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
| | - Wenhan Lin
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, People's Republic of China
- Institute of Ocean Research, Ningbo Institute of Marine Medicine, Peking University, Beijing 100191, People's Republic of China
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Ma S, Zhao D, Han X, Peng Y, Ren T, Wang M, Wan J, Ding J, Du X, Zhao F, Li Y, Zhang C. New application of Aspergillus versicolor in promoting plant growth after suppressing sterigmatocystin production via genome mining and engineering. Microb Biotechnol 2022; 16:139-147. [PMID: 36415948 PMCID: PMC9803325 DOI: 10.1111/1751-7915.14176] [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: 06/06/2022] [Revised: 10/18/2022] [Accepted: 11/10/2022] [Indexed: 11/24/2022] Open
Abstract
Aspergillus genus is a key component in fermentation and food processing. However, sterigmatocystin (STE)-a mycotoxin produced by several species of Aspergillus-limits the use of some Aspergillus species (such as Aspergillus versicolor, Aspergillus inflatus, and Aspergillus parasiticus) because of its toxicity and carcinogenicity. Here, we engineered an STE-free Aspergillus versicolor strain based on genome mining techniques. We sequenced and assembled the Aspergillus versicolor D5 genome (34.52 Mb), in which we identified 16 scaffolds and 54 biosynthetic gene clusters (BGCs). We silenced cytochrome P450 coding genes STC17 and STC27 by insertional inactivation. The production of STE in the Δstc17 mutant strain was increased by 282% but no STE was detected in the Δstc27 mutant. Metabolites of Δstc27 mutant exhibited growth-promoting effect on plants. Our study makes significant progress in improving the application of some Aspergillus strains by restricting their production of toxic and carcinogenic compounds.
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Affiliation(s)
- Siqi Ma
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
| | - Donglin Zhao
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
| | - Xiaobin Han
- Zunyi BranchGuizhou Tobacco CompanyZunyiChina
| | - Yulong Peng
- Zunyi BranchGuizhou Tobacco CompanyZunyiChina
| | - Tingting Ren
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
| | - Mei Wang
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
| | - Jun Wan
- Zunyi BranchGuizhou Tobacco CompanyZunyiChina
| | - Jilin Ding
- Zunyi BranchGuizhou Tobacco CompanyZunyiChina
| | - Xiuchun Du
- Jiaozhou Branch of Qingdao Tobacco Co. Ltd.QingdaoChina
| | - Fubin Zhao
- Huangdao Branch of Qingdao Tobacco Co. Ltd.QingdaoChina
| | - Yiqiang Li
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
| | - Chengsheng Zhang
- Marine Agriculture Research CenterTobacco Research Institute of Chinese Academy of Agricultural SciencesQingdaoChina
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Whole-Genome Sequence and Comparative Analysis of Trichoderma asperellum ND-1 Reveal Its Unique Enzymatic System for Efficient Biomass Degradation. Catalysts 2022. [DOI: 10.3390/catal12040437] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The lignocellulosic enzymes of Trichoderma asperellum have been intensely investigated toward efficient conversion of biomass into high-value chemicals/industrial products. However, lack of genome data is a remarkable hurdle for hydrolase systems studies. The secretory enzymes of newly isolated T. asperellum ND-1 during lignocellulose degradation are currently poorly known. Herein, a high-quality genomic sequence of ND-1, obtained by both Illumina HiSeq 2000 sequencing platforms and PacBio single-molecule real-time, has an assembly size of 35.75 Mb comprising 10,541 predicted genes. Secretome analysis showed that 895 proteins were detected, with 211 proteins associated with carbohydrate-active enzymes (CAZymes) responsible for biomass hydrolysis. Additionally, T. asperellum ND-1, T. atroviride IMI 206040, and T. virens Gv-298 shared 801 orthologues that were not identified in T. reesei QM6a, indicating that ND-1 may play critical roles in biological-control. In-depth analysis suggested that, compared with QM6a, the genome of ND-1 encoded a unique enzymatic system, especially hemicellulases and chitinases. Moreover, after comparative analysis of lignocellulase activities of ND-1 and other fungi, we found that ND-1 displayed higher hemicellulases (particularly xylanases) and comparable cellulases activities. Our analysis, combined with the whole-genome sequence information, offers a platform for designing advanced T. asperellum ND-1 strains for industrial utilizations, such as bioenergy production.
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A review of mycotoxin biosynthetic pathways: associated genes and their expressions under the influence of climatic factors. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Caesar LK, Kelleher NL, Keller NP. In the fungus where it happens: History and future propelling Aspergillus nidulans as the archetype of natural products research. Fungal Genet Biol 2020; 144:103477. [PMID: 33035657 DOI: 10.1016/j.fgb.2020.103477] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 02/08/2023]
Abstract
In 1990 the first fungal secondary metabolite biosynthetic gene was cloned in Aspergillus nidulans. Thirty years later, >30 biosynthetic gene clusters (BGCs) have been linked to specific natural products in this one fungal species. While impressive, over half of the BGCs in A. nidulans remain uncharacterized and their compounds structurally and functionally unknown. Here, we provide a comprehensive review of past advances that have enabled A. nidulans to rise to its current status as a natural product powerhouse focusing on the discovery and annotation of secondary metabolite clusters. From genome sequencing, heterologous expression, and metabolomics to CRISPR and epigenetic manipulations, we present a guided tour through the evolution of technologies developed and utilized in the last 30 years. These insights provide perspective to future efforts to fully unlock the biosynthetic potential of A. nidulans and, by extension, the potential of other filamentous fungi.
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Affiliation(s)
- Lindsay K Caesar
- Department of Chemistry, Northwestern University, Evanston, IL, United States
| | - Neil L Kelleher
- Department of Chemistry, Northwestern University, Evanston, IL, United States; Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States; Proteomics Center of Excellence, Northwestern University, Evanston, IL, United States
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin- Madison, Madison, WI, United States; Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, United States.
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6
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Ries LNA, Pardeshi L, Dong Z, Tan K, Steenwyk JL, Colabardini AC, Ferreira Filho JA, de Castro PA, Silva LP, Preite NW, Almeida F, de Assis LJ, dos Santos RAC, Bowyer P, Bromley M, Owens RA, Doyle S, Demasi M, Hernández DCR, Netto LES, Pupo MT, Rokas A, Loures FV, Wong KH, Goldman GH. The Aspergillus fumigatus transcription factor RglT is important for gliotoxin biosynthesis and self-protection, and virulence. PLoS Pathog 2020; 16:e1008645. [PMID: 32667960 PMCID: PMC7384679 DOI: 10.1371/journal.ppat.1008645] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 07/27/2020] [Accepted: 05/19/2020] [Indexed: 12/21/2022] Open
Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen that secretes an array of immune-modulatory molecules, including secondary metabolites (SMs), which contribute to enhancing fungal fitness and growth within the mammalian host. Gliotoxin (GT) is a SM that interferes with the function and recruitment of innate immune cells, which are essential for eliminating A. fumigatus during invasive infections. We identified a C6 Zn cluster-type transcription factor (TF), subsequently named RglT, important for A. fumigatus oxidative stress resistance, GT biosynthesis and self-protection. RglT regulates the expression of several gli genes of the GT biosynthetic gene cluster, including the oxidoreductase-encoding gene gliT, by directly binding to their respective promoter regions. Subsequently, RglT was shown to be important for virulence in a chemotherapeutic murine model of invasive pulmonary aspergillosis (IPA). Homologues of RglT and GliT are present in eurotiomycete and sordariomycete fungi, including the non-GT-producing fungus A. nidulans, where a conservation of function was described. Phylogenetically informed model testing led to an evolutionary scenario in which the GliT-based resistance mechanism is ancestral and RglT-mediated regulation of GliT occurred subsequently. In conclusion, this work describes the function of a previously uncharacterised TF in oxidative stress resistance, GT biosynthesis and self-protection in both GT-producing and non-producing Aspergillus species.
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Affiliation(s)
- Laure N. A. Ries
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lakhansing Pardeshi
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Zhiqiang Dong
- Faculty of Health Sciences, University of Macau, Macau SAR, China
| | - Kaeling Tan
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Faculty of Health Sciences, University of Macau, Macau SAR, China
- Centre for Precision Medicine and Research and Training, University of Macau, Macau SAR, China
| | - Jacob L. Steenwyk
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States of America
| | - Ana Cristina Colabardini
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Jaire A. Ferreira Filho
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Patricia A. de Castro
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Lilian P. Silva
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Nycolas W. Preite
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Fausto Almeida
- Faculty of Medicine of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Leandro J. de Assis
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Renato A. C. dos Santos
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Paul Bowyer
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Michael Bromley
- Manchester Fungal Infection Group, Division of Infection, Immunity and Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | | | - Sean Doyle
- Department of Biology, Maynooth University, Maynooth, Ireland
| | - Marilene Demasi
- Institute Butantan, Laboratory of Biochemistry and Biophysics, São Paulo, Brazil
| | - Diego C. R. Hernández
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | | | - Monica T. Pupo
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States of America
| | - Flavio V. Loures
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Koon H. Wong
- Genomics and Bioinformatics Core, Faculty of Health Sciences, University of Macau, Macau SAR, China
- Institute of Translational Medicine, University of Macau, Macau SAR, China
| | - Gustavo H. Goldman
- Faculty of Pharmaceutical Sciences of Ribeirao Preto, University of São Paulo, Ribeirão Preto, Brazil
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Nazhand A, Durazzo A, Lucarini M, Souto EB, Santini A. Characteristics, Occurrence, Detection and Detoxification of Aflatoxins in Foods and Feeds. Foods 2020; 9:E644. [PMID: 32443392 PMCID: PMC7278662 DOI: 10.3390/foods9050644] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/09/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Mycotoxin contamination continues to be a food safety concern globally, with the most toxic being aflatoxins. On-farm aflatoxins, during food transit or storage, directly or indirectly result in the contamination of foods, which affects the liver, immune system and reproduction after infiltration into human beings and animals. There are numerous reports on aflatoxins focusing on achieving appropriate methods for quantification, precise detection and control in order to ensure consumer safety. In 2012, the International Agency for Research on Cancer (IARC) classified aflatoxins B1, B2, G1, G2, M1 and M2 as group 1 carcinogenic substances, which are a global human health concern. Consequently, this review article addresses aflatoxin chemical properties and biosynthetic processes; aflatoxin contamination in foods and feeds; health effects in human beings and animals due to aflatoxin exposure, as well as aflatoxin detection and detoxification methods.
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Affiliation(s)
- Amirhossein Nazhand
- Department of Biotechnology, Sari Agricultural Science and Natural Resource University, 9th km of Farah Abad Road, Mazandaran 48181-68984, Iran;
| | - Alessandra Durazzo
- CREA-Research Centre for Food and Nutrition, Via Ardeatina 546, 00178 Roma, Italy; (A.D.); (M.L.)
| | - Massimo Lucarini
- CREA-Research Centre for Food and Nutrition, Via Ardeatina 546, 00178 Roma, Italy; (A.D.); (M.L.)
| | - Eliana B. Souto
- Faculty of Pharmacy of University of Coimbra, Azinhaga de Santa Comba, Polo III-Saúde, 3000-548 Coimbra, Portugal;
- CEB-Centre of Biological Engineering, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
| | - Antonello Santini
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy
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Aflatoxin Biosynthesis and Genetic Regulation: A Review. Toxins (Basel) 2020; 12:toxins12030150. [PMID: 32121226 PMCID: PMC7150809 DOI: 10.3390/toxins12030150] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 01/27/2020] [Accepted: 02/25/2020] [Indexed: 12/15/2022] Open
Abstract
The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the production of toxic secondary metabolites. Taking advantage of these technologies to improve food safety, the molecular study of toxinogenic species can help elucidate the mechanisms underlying toxin production and enable the development of new effective strategies to control fungal toxicity. Numerous studies have been made on genes involved in aflatoxin B1 (AFB1) production, one of the most hazardous carcinogenic toxins for humans and animals. The current review presents the roles of these different genes and their possible impact on AFB1 production. We focus on the toxinogenic strains Aspergillus flavus and A. parasiticus, primary contaminants and major producers of AFB1 in crops. However, genetic reports on A. nidulans are also included because of the capacity of this fungus to produce sterigmatocystin, the penultimate stable metabolite during AFB1 production. The aim of this review is to provide a general overview of the AFB1 enzymatic biosynthesis pathway and its link with the genes belonging to the AFB1 cluster. It also aims to illustrate the role of global environmental factors on aflatoxin production and the recent data that demonstrate an interconnection between genes regulated by these environmental signals and aflatoxin biosynthetic pathway.
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Boyce KJ, De Souza DP, Dayalan S, Pasricha S, Tull D, McConville MJ, Andrianopoulos A. Talaromyces marneffei simA Encodes a Fungal Cytochrome P450 Essential for Survival in Macrophages. mSphere 2018; 3:e00056-18. [PMID: 29577082 PMCID: PMC5863032 DOI: 10.1128/msphere.00056-18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 02/23/2018] [Indexed: 11/20/2022] Open
Abstract
Fungi are adept at occupying specific environmental niches and often exploit numerous secondary metabolites generated by the cytochrome P450 (CYP) monoxygenases. This report describes the characterization of a yeast-specific CYP encoded by simA ("survival in macrophages"). Deletion of simA does not affect yeast growth at 37°C in vitro but is essential for yeast cell production during macrophage infection. The ΔsimA strain exhibits reduced conidial germination and intracellular growth of yeast in macrophages, suggesting that the enzymatic product of SimA is required for normal fungal growth in vivo. Intracellular ΔsimA yeast cells exhibit cell wall defects, and metabolomic and chemical sensitivity data suggest that SimA may promote chitin synthesis or deposition in vitro. In vivo, ΔsimA yeast cells subsequently lyse and are degraded, suggesting that SimA may increase resistance to and/or suppress host cell biocidal effectors. The results suggest that simA synthesizes a secondary metabolite that allows T. marneffei to occupy the specific intracellular environmental niche within the macrophage. IMPORTANCE This study in a dimorphic fungal pathogen uncovered a role for a yeast-specific cytochrome P450 (CYP)-encoding gene in the ability of T. marneffei to grow as yeast cells within the host macrophages. This report will inspire further research into the role of CYPs and secondary metabolite synthesis during fungal pathogenic growth.
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Affiliation(s)
- Kylie J. Boyce
- School of Biosciences, The University of Melbourne, Melbourne, Australia
| | - David P. De Souza
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Saravanan Dayalan
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Shivani Pasricha
- School of Biosciences, The University of Melbourne, Melbourne, Australia
| | - Dedreia Tull
- Metabolomics Australia, Bio21 Institute, The University of Melbourne, Melbourne, Australia
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology, Bio21 Institute, The University of Melbourne, Melbourne, Australia
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Seifbarghi S, Borhan MH, Wei Y, Coutu C, Robinson SJ, Hegedus DD. Changes in the Sclerotinia sclerotiorum transcriptome during infection of Brassica napus. BMC Genomics 2017; 18:266. [PMID: 28356071 PMCID: PMC5372324 DOI: 10.1186/s12864-017-3642-5] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 03/18/2017] [Indexed: 11/17/2022] Open
Abstract
Background Sclerotinia sclerotiorum causes stem rot in Brassica napus, which leads to lodging and severe yield losses. Although recent studies have explored significant progress in the characterization of individual S. sclerotiorum pathogenicity factors, a gap exists in profiling gene expression throughout the course of S. sclerotiorum infection on a host plant. In this study, RNA-Seq analysis was performed with focus on the events occurring through the early (1 h) to the middle (48 h) stages of infection. Results Transcript analysis revealed the temporal pattern and amplitude of the deployment of genes associated with aspects of pathogenicity or virulence during the course of S. sclerotiorum infection on Brassica napus. These genes were categorized into eight functional groups: hydrolytic enzymes, secondary metabolites, detoxification, signaling, development, secreted effectors, oxalic acid and reactive oxygen species production. The induction patterns of nearly all of these genes agreed with their predicted functions. Principal component analysis delineated gene expression patterns that signified transitions between pathogenic phases, namely host penetration, ramification and necrotic stages, and provided evidence for the occurrence of a brief biotrophic phase soon after host penetration. Conclusions The current observations support the notion that S. sclerotiorum deploys an array of factors and complex strategies to facilitate host colonization and mitigate host defenses. This investigation provides a broad overview of the sequential expression of virulence/pathogenicity-associated genes during infection of B. napus by S. sclerotiorum and provides information for further characterization of genes involved in the S. sclerotiorum-host plant interactions. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3642-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shirin Seifbarghi
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada.,Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - M Hossein Borhan
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Canada
| | - Cathy Coutu
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Stephen J Robinson
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada
| | - Dwayne D Hegedus
- Agriculture and Agri-Food Canada, 107 Science Place, Saskatoon, SK, S7N 0X2, Canada. .,Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Canada.
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11
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Prasad P, Varshney D, Adholeya A. Whole genome annotation and comparative genomic analyses of bio-control fungus Purpureocillium lilacinum. BMC Genomics 2015; 16:1004. [PMID: 26607873 PMCID: PMC4658809 DOI: 10.1186/s12864-015-2229-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/18/2015] [Indexed: 01/11/2023] Open
Abstract
Background The fungus Purpureocillium lilacinum is widely known as a biological control agent against plant parasitic nematodes. This research article consists of genomic annotation of the first draft of whole genome sequence of P. lilacinum. The study aims to decipher the putative genetic components of the fungus involved in nematode pathogenesis by performing comparative genomic analysis with nine closely related fungal species in Hypocreales. Results de novo genomic assembly was done and a total of 301 scaffolds were constructed for P. lilacinum genomic DNA. By employing structural genome prediction models, 13, 266 genes coding for proteins were predicted in the genome. Approximately 73 % of the predicted genes were functionally annotated using Blastp, InterProScan and Gene Ontology. A 14.7 % fraction of the predicted genes shared significant homology with genes in the Pathogen Host Interactions (PHI) database. The phylogenomic analysis carried out using maximum likelihood RAxML algorithm provided insight into the evolutionary relationship of P. lilacinum. In congruence with other closely related species in the Hypocreales namely, Metarhizium spp., Pochonia chlamydosporia, Cordyceps militaris, Trichoderma reesei and Fusarium spp., P. lilacinum has large gene sets coding for G-protein coupled receptors (GPCRs), proteases, glycoside hydrolases and carbohydrate esterases that are required for degradation of nematode-egg shell components. Screening of the genome by Antibiotics & Secondary Metabolite Analysis Shell (AntiSMASH) pipeline indicated that the genome potentially codes for a variety of secondary metabolites, possibly required for adaptation to heterogeneous lifestyles reported for P. lilacinum. Significant up-regulation of subtilisin-like serine protease genes in presence of nematode eggs in quantitative real-time analyses suggested potential role of serine proteases in nematode pathogenesis. Conclusions The data offer a better understanding of Purpureocillium lilacinum genome and will enhance our understanding on the molecular mechanism involved in nematophagy. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-2229-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pushplata Prasad
- TERI Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari,Faridabad Road, Gurgaon, Haryana, 122 001, India.
| | - Deepti Varshney
- TERI Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari,Faridabad Road, Gurgaon, Haryana, 122 001, India.
| | - Alok Adholeya
- TERI Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari,Faridabad Road, Gurgaon, Haryana, 122 001, India.
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Chen W, Lee MK, Jefcoate C, Kim SC, Chen F, Yu JH. Fungal cytochrome p450 monooxygenases: their distribution, structure, functions, family expansion, and evolutionary origin. Genome Biol Evol 2014; 6:1620-34. [PMID: 24966179 PMCID: PMC4122930 DOI: 10.1093/gbe/evu132] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cytochrome P450 (CYP) monooxygenase superfamily contributes a broad array of biological functions in living organisms. In fungi, CYPs play diverse and pivotal roles in versatile metabolism and fungal adaptation to specific ecological niches. In this report, CYPomes in the 47 genomes of fungi belong to the phyla Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota have been studied. The comparison of fungal CYPomes suggests that generally fungi possess abundant CYPs belonging to a variety of families with the two global families CYP51 and CYP61, indicating individuation of CYPomes during the evolution of fungi. Fungal CYPs show highly conserved characteristic motifs, but very low overall sequence similarities. The characteristic motifs of fungal CYPs are distinguishable from those of CYPs in animals, plants, and especially archaea and bacteria. The four representative motifs contribute to the general function of CYPs. Fungal CYP51s and CYP61s can be used as the models for the substrate recognition sites analysis. The CYP proteins are clustered into 15 clades and the phylogenetic analyses suggest that the wide variety of fungal CYPs has mainly arisen from gene duplication. Two large duplication events might have been associated with the booming of Ascomycota and Basidiomycota. In addition, horizontal gene transfer also contributes to the diversification of fungal CYPs. Finally, a possible evolutionary scenario for fungal CYPs along with fungal divergences is proposed. Our results provide the fundamental information for a better understanding of CYP distribution, structure and function, and new insights into the evolutionary events of fungal CYPs along with the evolution of fungi.
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Affiliation(s)
- Wanping Chen
- Department of Food Microbiology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, ChinaDepartment of Bacteriology and Genetics, University of Wisconsin-Madison
| | - Mi-Kyung Lee
- Department of Bacteriology and Genetics, University of Wisconsin-Madison
| | - Colin Jefcoate
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison
| | - Sun-Chang Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Dae-Jon, Republic of Korea
| | - Fusheng Chen
- Department of Food Microbiology, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei Province, China
| | - Jae-Hyuk Yu
- Department of Bacteriology and Genetics, University of Wisconsin-Madison
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Guo L, Han L, Yang L, Zeng H, Fan D, Zhu Y, Feng Y, Wang G, Peng C, Jiang X, Zhou D, Ni P, Liang C, Liu L, Wang J, Mao C, Fang X, Peng M, Huang J. Genome and transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. cubense causing banana vascular wilt disease. PLoS One 2014; 9:e95543. [PMID: 24743270 PMCID: PMC3990668 DOI: 10.1371/journal.pone.0095543] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 03/28/2014] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND The asexual fungus Fusarium oxysporum f. sp. cubense (Foc) causing vascular wilt disease is one of the most devastating pathogens of banana (Musa spp.). To understand the molecular underpinning of pathogenicity in Foc, the genomes and transcriptomes of two Foc isolates were sequenced. METHODOLOGY/PRINCIPAL FINDINGS Genome analysis revealed that the genome structures of race 1 and race 4 isolates were highly syntenic with those of F. oxysporum f. sp. lycopersici strain Fol4287. A large number of putative virulence associated genes were identified in both Foc genomes, including genes putatively involved in root attachment, cell degradation, detoxification of toxin, transport, secondary metabolites biosynthesis and signal transductions. Importantly, relative to the Foc race 1 isolate (Foc1), the Foc race 4 isolate (Foc4) has evolved with some expanded gene families of transporters and transcription factors for transport of toxins and nutrients that may facilitate its ability to adapt to host environments and contribute to pathogenicity to banana. Transcriptome analysis disclosed a significant difference in transcriptional responses between Foc1 and Foc4 at 48 h post inoculation to the banana 'Brazil' in comparison with the vegetative growth stage. Of particular note, more virulence-associated genes were up regulated in Foc4 than in Foc1. Several signaling pathways like the mitogen-activated protein kinase Fmk1 mediated invasion growth pathway, the FGA1-mediated G protein signaling pathway and a pathogenicity associated two-component system were activated in Foc4 rather than in Foc1. Together, these differences in gene content and transcription response between Foc1 and Foc4 might account for variation in their virulence during infection of the banana variety 'Brazil'. CONCLUSIONS/SIGNIFICANCE Foc genome sequences will facilitate us to identify pathogenicity mechanism involved in the banana vascular wilt disease development. These will thus advance us develop effective methods for managing the banana vascular wilt disease, including improvement of disease resistance in banana.
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Affiliation(s)
- Lijia Guo
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | - Laying Yang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Huicai Zeng
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | | | | | - Guofen Wang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | | | | | | | - Changcong Liang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Lei Liu
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Jun Wang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Chao Mao
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | | | - Ming Peng
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Junsheng Huang
- Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
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14
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Chooi YH, Hong YJ, Cacho RA, Tantillo DJ, Tang Y. A cytochrome P450 serves as an unexpected terpene cyclase during fungal meroterpenoid biosynthesis. J Am Chem Soc 2013; 135:16805-8. [PMID: 24161266 DOI: 10.1021/ja408966t] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Viridicatumtoxin (1) is a tetracycline-like fungal meroterpenoid with a unique, fused spirobicyclic ring system. Puzzlingly, no dedicated terpene cyclase is found in the gene cluster identified in Penicillium aethiopicum. Cytochrome P450 enzymes VrtE and VrtK in the vrt gene cluster were shown to catalyze C5-hydroxylation and spirobicyclic ring formation, respectively. Feeding acyclic previridicatumtoxin to Saccharomyces cerevisiae expressing VrtK confirmed that VrtK is the sole enzyme required for cyclizing the geranyl moiety. Thus, VrtK is the first example of a P450 that can catalyze terpene cyclization, most likely via initial oxidation of C17 to an allylic carbocation. Quantum chemical modeling revealed a possible new tertiary carbocation intermediate E that forms after allylic carbocation formation. Intermediate E can readily undergo concerted 1,2-alkyl shift/1,3-hydride shift, either spontaneously or further aided by VrtK, followed by C7 Friedel-Crafts alkylation to afford 1. The most likely stereochemical course of the reaction was proposed on the basis of the results of our computations.
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Affiliation(s)
- Yit-Heng Chooi
- Department of Chemical and Biomolecular Engineering and ‡Department of Chemistry and Biochemistry, University of California , Los Angeles, California 90095, United States
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15
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Comprehensive annotation of secondary metabolite biosynthetic genes and gene clusters of Aspergillus nidulans, A. fumigatus, A. niger and A. oryzae. BMC Microbiol 2013; 13:91. [PMID: 23617571 PMCID: PMC3689640 DOI: 10.1186/1471-2180-13-91] [Citation(s) in RCA: 195] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/15/2013] [Indexed: 11/24/2022] Open
Abstract
Background Secondary metabolite production, a hallmark of filamentous fungi, is an expanding area of research for the Aspergilli. These compounds are potent chemicals, ranging from deadly toxins to therapeutic antibiotics to potential anti-cancer drugs. The genome sequences for multiple Aspergilli have been determined, and provide a wealth of predictive information about secondary metabolite production. Sequence analysis and gene overexpression strategies have enabled the discovery of novel secondary metabolites and the genes involved in their biosynthesis. The Aspergillus Genome Database (AspGD) provides a central repository for gene annotation and protein information for Aspergillus species. These annotations include Gene Ontology (GO) terms, phenotype data, gene names and descriptions and they are crucial for interpreting both small- and large-scale data and for aiding in the design of new experiments that further Aspergillus research. Results We have manually curated Biological Process GO annotations for all genes in AspGD with recorded functions in secondary metabolite production, adding new GO terms that specifically describe each secondary metabolite. We then leveraged these new annotations to predict roles in secondary metabolism for genes lacking experimental characterization. As a starting point for manually annotating Aspergillus secondary metabolite gene clusters, we used antiSMASH (antibiotics and Secondary Metabolite Analysis SHell) and SMURF (Secondary Metabolite Unknown Regions Finder) algorithms to identify potential clusters in A. nidulans, A. fumigatus, A. niger and A. oryzae, which we subsequently refined through manual curation. Conclusions This set of 266 manually curated secondary metabolite gene clusters will facilitate the investigation of novel Aspergillus secondary metabolites.
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16
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Yu J. Current understanding on aflatoxin biosynthesis and future perspective in reducing aflatoxin contamination. Toxins (Basel) 2012; 4:1024-57. [PMID: 23202305 PMCID: PMC3509697 DOI: 10.3390/toxins4111024] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 01/20/2023] Open
Abstract
Traditional molecular techniques have been used in research in discovering the genes and enzymes that are involved in aflatoxin formation and genetic regulation. We cloned most, if not all, of the aflatoxin pathway genes. A consensus gene cluster for aflatoxin biosynthesis was discovered in 2005. The factors that affect aflatoxin formation have been studied. In this report, the author summarized the current status of research progress and future possibilities that may be used for solving aflatoxin contamination.
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Affiliation(s)
- Jiujiang Yu
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA/ARS), New Orleans, LA 70112, USA.
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17
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Saha D, Fetzner R, Burkhardt B, Podlech J, Metzler M, Dang H, Lawrence C, Fischer R. Identification of a polyketide synthase required for alternariol (AOH) and alternariol-9-methyl ether (AME) formation in Alternaria alternata. PLoS One 2012; 7:e40564. [PMID: 22792370 PMCID: PMC3391263 DOI: 10.1371/journal.pone.0040564] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 06/09/2012] [Indexed: 11/18/2022] Open
Abstract
Alternaria alternata produces more than 60 secondary metabolites, among which alternariol (AOH) and alternariol-9-methyl ether (AME) are important mycotoxins. Whereas the toxicology of these two polyketide-based compounds has been studied, nothing is known about the genetics of their biosynthesis. One of the postulated core enzymes in the biosynthesis of AOH and AME is polyketide synthase (PKS). In a draft genome sequence of A. alternata we identified 10 putative PKS-encoding genes. The timing of the expression of two PKS genes, pksJ and pksH, correlated with the production of AOH and AME. The PksJ and PksH proteins are predicted to be 2222 and 2821 amino acids in length, respectively. They are both iterative type I reducing polyketide synthases. PksJ harbors a peroxisomal targeting sequence at the C-terminus, suggesting that the biosynthesis occurs at least partly in these organelles. In the vicinity of pksJ we found a transcriptional regulator, altR, involved in pksJ induction and a putative methyl transferase, possibly responsible for AME formation. Downregulation of pksJ and altR caused a large decrease of alternariol formation, suggesting that PksJ is the polyketide synthase required for the postulated Claisen condensations during the biosynthesis. No other enzymes appeared to be required. PksH downregulation affected pksJ expression and thus caused an indirect effect on AOH production.
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Affiliation(s)
- Debjani Saha
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ramona Fetzner
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Britta Burkhardt
- Department of Food Chemistry, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Joachim Podlech
- Karlsruhe Institute of Technology (KIT) - South Campus, Institute of Organic Chemistry, Karlsruhe, Germany
| | - Manfred Metzler
- Department of Food Chemistry, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
| | - Ha Dang
- Virginia Bioinformatics Institute, Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Christopher Lawrence
- Virginia Bioinformatics Institute, Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Reinhard Fischer
- Department of Microbiology, Karlsruhe Institute of Technology (KIT) - South Campus, Institute for Applied Biosciences, Karlsruhe, Germany
- * E-mail:
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18
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Klejnstrup ML, Frandsen RJN, Holm DK, Nielsen MT, Mortensen UH, Larsen TO, Nielsen JB. Genetics of Polyketide Metabolism in Aspergillus nidulans. Metabolites 2012; 2:100-33. [PMID: 24957370 PMCID: PMC3901194 DOI: 10.3390/metabo2010100] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 12/23/2011] [Accepted: 01/17/2012] [Indexed: 12/12/2022] Open
Abstract
Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.
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Affiliation(s)
- Marie L Klejnstrup
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B221, DK-2800 Kgs. Lyngby, Denmark.
| | - Rasmus J N Frandsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Dorte K Holm
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Morten T Nielsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Uffe H Mortensen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
| | - Thomas O Larsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B221, DK-2800 Kgs. Lyngby, Denmark.
| | - Jakob B Nielsen
- Department of Systems Biology, Center for Microbial Biotechnology, Technical University of Denmark, Søltofts Plads B223, DK-2800 Kgs. Lyngby, Denmark.
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19
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Peña-Montes C, Lange S, Flores I, Castro-Ochoa D, Schmid R, Cruz-García F, Farrés A. Molecular characterization of StcI esterase from Aspergillus nidulans. Appl Microbiol Biotechnol 2009; 84:917-26. [PMID: 19440704 DOI: 10.1007/s00253-009-2005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2009] [Revised: 04/01/2009] [Accepted: 04/07/2009] [Indexed: 11/24/2022]
Abstract
Aspergillus nidulans produces StcI esterase, which is involved in the biosynthesis of sterigmatocystin, a precursor of aflatoxins. Previous reports of this esterase in A. nidulans suggest that it is composed of 286 amino acid residues with a theoretical molecular mass of 31 kDa. Various conditions were evaluated to determine the optimal expression conditions for StcI; the highest level was observed when A. nidulans was cultured in solid oat media. Various esterases were expressed differentially according to the culture media used. However, specific antibodies designed to detect StcI reacted with a protein with an unexpected molecular mass of 35 kDa in cell extracts from all expression conditions. Analysis of the gene sequence and already reported expressed sequence tags indicated the presence of an additional 29-amino-acid N-terminal region of StcI, which is not a signal peptide and which has not been previously reported. We also detected the presence of this additional N-terminal region using reverse-transcriptase polymerase chain reaction. The complete protein (NStcI) was cloned and successfully expressed in Pichia pastoris.
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Affiliation(s)
- Carolina Peña-Montes
- Food and Biotechnology Department, Chemistry Faculty, National Autonomous University of Mexico , Ciudad Universitaria, Mexico City, DF 04510, Mexico
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Cleveland TE, Yu J, Bhatnagar D, Chen Z, Brown RL, Chang P, Cary JW. Progress in Elucidating the Molecular Basis of the Host Plant—AspergillusFlavusInteraction, a Basis for Devising Strategies to Reduce Aflatoxin Contamination in Crops. ACTA ACUST UNITED AC 2008. [DOI: 10.1081/txr-200027892] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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21
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Buntin K, Rachid S, Scharfe M, Blöcker H, Weissman K, Müller R. Produktion der Isochromanon-Antimykotika Ajudazol A und B inChondromyces crocatus Cm c5: Biosynthesemaschinerie und Cytochrom-P450-Modifikationen. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200705569] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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22
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Buntin K, Rachid S, Scharfe M, Blöcker H, Weissman K, Müller R. Production of the Antifungal Isochromanone Ajudazols A and B inChondromyces crocatus Cm c5: Biosynthetic Machinery and Cytochrome P450 Modifications. Angew Chem Int Ed Engl 2008; 47:4595-9. [DOI: 10.1002/anie.200705569] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Smith CA, Woloshuk CP, Robertson D, Payne GA. Silencing of the aflatoxin gene cluster in a diploid strain of Aspergillus flavus is suppressed by ectopic aflR expression. Genetics 2007; 176:2077-86. [PMID: 17565943 PMCID: PMC1950615 DOI: 10.1534/genetics.107.073460] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Aflatoxins are toxic secondary metabolites produced by a 70-kb cluster of genes in Aspergillus flavus. The cluster genes are coordinately regulated and reside as a single copy within the genome. Diploids between a wild-type strain and a mutant (649) lacking the aflatoxin gene cluster fail to produce aflatoxin or transcripts of the aflatoxin pathway genes. This dominant phenotype is rescued in diploids between a wild-type strain and a transformant of the mutant containing an ectopic copy of aflR, the transcriptional regulator of the aflatoxin biosynthetic gene cluster. Further characterization of the mutant showed that it is missing 317 kb of chromosome III, including the known genes for aflatoxin biosynthesis. In addition, 939 kb of chromosome II is present as a duplication on chromosome III in the region previously containing the aflatoxin gene cluster. The lack of aflatoxin production in the diploid was not due to a unique or a mis-expressed repressor of aflR. Instead a form of reversible silencing based on the position of aflR is likely preventing the aflatoxin genes from being expressed in 649 x wild-type diploids. Gene expression analysis revealed the silencing effect is specific to the aflatoxin gene cluster.
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Affiliation(s)
- Carrie A. Smith
- Department of Genetics, Department of Plant Biology and Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Charles P. Woloshuk
- Department of Genetics, Department of Plant Biology and Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Dominique Robertson
- Department of Genetics, Department of Plant Biology and Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
| | - Gary A. Payne
- Department of Genetics, Department of Plant Biology and Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695 and Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907
- Corresponding author: Center for Integrated Fungal Research and Department of Plant Pathology, North Carolina State University, Box 7567, Raleigh, NC 27695-7567.E-mail:
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Sakuno E, Wen Y, Hatabayashi H, Arai H, Aoki C, Yabe K, Nakajima H. Aspergillus parasiticus cyclase catalyzes two dehydration steps in aflatoxin biosynthesis. Appl Environ Microbiol 2005; 71:2999-3006. [PMID: 15932995 PMCID: PMC1151850 DOI: 10.1128/aem.71.6.2999-3006.2005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the aflatoxin biosynthetic pathway, 5'-oxoaverantin (OAVN) cyclase, the cytosolic enzyme, catalyzes the reaction from OAVN to (2'S,5'S)-averufin (AVR) (E. Sakuno, K. Yabe, and H. Nakajima, Appl. Environ. Microbiol. 69:6418-6426, 2003). Interestingly, the N-terminal 25-amino-acid sequence of OAVN cyclase completely matched an internal sequence of the versiconal (VHOH) cyclase that was deduced from its gene (vbs). The purified OAVN cyclase also catalyzed the reaction from VHOH to versicolorin B (VB). In a competition experiment using the cytosol fraction of Aspergillus parasiticus, a high concentration of VHOH inhibited the enzyme reaction from OAVN to AVR, and instead VB was newly formed. The recombinant Vbs protein, which was expressed in Pichia pastoris, showed OAVN cyclase activity, as well as VHOH cyclase activity. A mutant of A. parasiticus SYS-4 (= NRRL 2999) with vbs deleted accumulated large amounts of OAVN, 5'-hydroxyaverantin, averantin, AVR, and averufanin in the mycelium. These results indicated that the cyclase encoded by the vbs gene is also involved in the reaction from OAVN to AVR in aflatoxin biosynthesis. Small amounts of VHOH, VB, and aflatoxins also accumulated in the same mutant, and this accumulation may have been due to an unknown enzyme(s) not involved in aflatoxin biosynthesis. This is the first report of one enzyme catalyzing two different reactions in a pathway of secondary metabolism.
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Affiliation(s)
- Emi Sakuno
- National Food Research Institute, Tsukuba, Ibaraki 305-8642, Japan
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Chang PK, Yabe K, Yu J. The Aspergillus parasiticus estA-encoded esterase converts versiconal hemiacetal acetate to versiconal and versiconol acetate to versiconol in aflatoxin biosynthesis. Appl Environ Microbiol 2004; 70:3593-9. [PMID: 15184162 PMCID: PMC427728 DOI: 10.1128/aem.70.6.3593-3599.2004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In aflatoxin biosynthesis, the pathway for the conversion of 1-hydroxyversicolorone to versiconal hemiacetal acetate (VHA) to versiconal (VHOH) is part of a metabolic grid. In the grid, the steps from VHA to VHOH and from versiconol acetate (VOAc) to versiconol (VOH) may be catalyzed by the same esterase. Several esterase activities are associated with the conversion of VHA to VHOH, but only one esterase gene (estA) is present in the complete aflatoxin gene cluster of Aspergillus parasiticus. We deleted the estA gene from A. parasiticus SRRC 2043, an O-methylsterigmatocystin (OMST)-accumulating strain. The estA-deleted mutants were pigmented and accumulated mainly VHA and versicolorin A (VA). A small amount of VOAc and other downstream aflatoxin intermediates, including VHOH, versicolorin B, and OMST, also were accumulated. In contrast, a VA-accumulating mutant, NIAH-9, accumulated VA exclusively and neither VHA nor VOAc were produced. Addition of the esterase inhibitor dichlorvos (dimethyl 2,2-dichlorovinylphosphate) to the transformation recipient strain RHN1, an estA-deleted mutant, or NIAH-9 resulted in the accumulation of only VHA and VOAc. In in vitro enzyme assays, the levels of the esterase activities catalyzing the conversion of VHA to VHOH in the cell extracts of two estA-deleted mutants were decreased to approximately 10% of that seen with RHN1. Similar decreases in the esterase activities catalyzing the conversion of VOAc to VOH were also obtained. Thus, the estA-encoded esterase catalyzes the conversion of both VHA to VHOH and VOAc to VOH during aflatoxin biosynthesis.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124, USA.
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Yu J, Chang PK, Ehrlich KC, Cary JW, Bhatnagar D, Cleveland TE, Payne GA, Linz JE, Woloshuk CP, Bennett JW. Clustered pathway genes in aflatoxin biosynthesis. Appl Environ Microbiol 2004; 70:1253-62. [PMID: 15006741 PMCID: PMC368384 DOI: 10.1128/aem.70.3.1253-1262.2004] [Citation(s) in RCA: 545] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Jiujiang Yu
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana 70124, USA.
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27
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Bradshaw RE, Bhatnagar D, Ganley RJ, Gillman CJ, Monahan BJ, Seconi JM. Dothistroma pini, a forest pathogen, contains homologs of aflatoxin biosynthetic pathway genes. Appl Environ Microbiol 2002; 68:2885-92. [PMID: 12039746 PMCID: PMC123981 DOI: 10.1128/aem.68.6.2885-2892.2002] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2001] [Accepted: 03/29/2002] [Indexed: 11/20/2022] Open
Abstract
Homologs of aflatoxin biosynthetic genes have been identified in the pine needle pathogen Dothistroma pini. D. pini produces dothistromin, a difuranoanthraquinone toxin with structural similarity to the aflatoxin precursor versicolorin B. Previous studies with purified dothistromin suggest a possible role for this toxin in pathogenicity. By using an aflatoxin gene as a hybridization probe, a genomic D. pini clone was identified that contained four dot genes with similarity to genes in aflatoxin and sterigmatocystin gene clusters with predicted activities of a ketoreductase (dotA), oxidase (dotB), major facilitator superfamily transporter (dotC), and thioesterase (dotD). A D. pini dotA mutant was made by targeted gene replacement and shown to be severely impaired in dothistromin production, confirming that dotA is involved in dothistromin biosynthesis. Accumulation of versicolorin A (a precursor of aflatoxin) by the dotA mutant confirms that the dotA gene product is involved in an aflatoxin-like biosynthetic pathway. Since toxin genes have been found to be clustered in fungi in every case analyzed so far, it is speculated that the four dot genes may comprise part of a dothistromin biosynthetic gene cluster. A fifth gene, ddhA, is not a homolog of aflatoxin genes and could be at one end of the dothistromin cluster. These genes will allow comparative biochemical and genetic studies of the aflatoxin and dothistromin biosynthetic pathways and may also lead to new ways to control Dothistroma needle blight.
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Affiliation(s)
- Rosie E Bradshaw
- Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
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28
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Abstract
Coprinus cinereus has two main types of mycelia, the asexual monokaryon and the sexual dikaryon, formed by fusion of compatible monokaryons. Syngamy (plasmogamy) and karyogamy are spatially and temporally separated, which is typical for basidiomycetous fungi. This property of the dikaryon enables an easy exchange of nuclear partners in further dikaryotic-monokaryotic and dikaryotic-dikaryotic mycelial fusions. Fruiting bodies normally develop on the dikaryon, and the cytological process of fruiting-body development has been described in its principles. Within the specialized basidia, present within the gills of the fruiting bodies, karyogamy occurs in a synchronized manner. It is directly followed by meiosis and by the production of the meiotic basidiospores. The synchrony of karyogamy and meiosis has made the fungus a classical object to study meiotic cytology and recombination. Several genes involved in these processes have been identified. Both monokaryons and dikaryons can form multicellular resting bodies (sclerotia) and different types of mitotic spores, the small uninucleate aerial oidia, and, within submerged mycelium, the large thick-walled chlamydospores. The decision about whether a structure will be formed is made on the basis of environmental signals (light, temperature, humidity, and nutrients). Of the intrinsic factors that control development, the products of the two mating type loci are most important. Mutant complementation and PCR approaches identified further genes which possibly link the two mating-type pathways with each other and with nutritional regulation, for example with the cAMP signaling pathway. Among genes specifically expressed within the fruiting body are those for two galectins, beta-galactoside binding lectins that probably act in hyphal aggregation. These genes serve as molecular markers to study development in wild-type and mutant strains. The isolation of genes for potential non-DNA methyltransferases, needed for tissue formation within the fruiting body, promises the discovery of new signaling pathways, possibly involving secondary fungal metabolites.
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Affiliation(s)
- U Kües
- ETH Zürich, Institut für Mikrobiologie, CH-8092 Zürich, Switzerland
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29
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Yu J, Woloshuk CP, Bhatnagar D, Cleveland TE. Cloning and characterization of avfA and omtB genes involved in aflatoxin biosynthesis in three Aspergillus species. Gene 2000; 248:157-67. [PMID: 10806361 DOI: 10.1016/s0378-1119(00)00126-8] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The biosynthesis of aflatoxins (B(1), G(1), B(2), and G(2)) is a multi-enzyme process controlled genetically by over 20 genes. In this study, we report the identification and characterization of the avfA gene, which was found to be involved in the conversion of averufin (AVF) to versiconal hemiacetal acetate (VHA), in Aspergillus parasiticus and A. flavus; a copy of avfA gene was also cloned from a non-aflatoxin producing strain A. sojae. Complementation of an averufin-accumulating, non-aflatoxigenic mutant strain of A. parasiticus, SRRC 165, with the avfA gene cloned from A. flavus, restored the ability of the mutant to convert AVF to VHA and to produce aflatoxins B(1), G(1), B(2), and G(2). Sequence analysis revealed that a single amino acid replacement from aspartic acid to asparagine disabled the function of the enzyme in the mutant strain SRRC 165. The A. parasiticus avfA was identified to be a homolog of previously sequenced, but functionally unassigned transcript, stcO, in A. nidulans based on sequence homology at both nucleotide (57%) and amino acid (55%) levels. In addition to avfA, another aflatoxin pathway gene, omtB, encoding for an O-methyltransferase involved in the conversion of demethylsterigmatocystin (DMST) to sterigmatocystin (ST) and dihydrodemethylsterigmatocystin (DHDMST) to dihydrosterigmatocystin (DHST), was cloned from A. parasiticus, A. flavus, and A. sojae. The omtB gene was found to be highly homologous to stcP from A. nidulans, which has been reported earlier to be involved in a similar enzymatic step for the sterigmatocystin formation in that species. RT-PCR data demonstrated that both the avfA and avfA1 as well as omtB genes in A. parasiticus were expressed only in the aflatoxin-conducive medium. An analysis of the degrees of homology for the two reported genes between the Aspergillus species A. parasiticus, A. flavus, A. nidulans and A. sojae was conducted.
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Affiliation(s)
- J Yu
- Southern Regional Research Center, USDA, Agricultural Research Service, New Orleans, LA 70179, USA.
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30
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Keller NP, Watanabe CM, Kelkar HS, Adams TH, Townsend CA. Requirement of monooxygenase-mediated steps for sterigmatocystin biosynthesis by Aspergillus nidulans. Appl Environ Microbiol 2000; 66:359-62. [PMID: 10618248 PMCID: PMC91830 DOI: 10.1128/aem.66.1.359-362.2000] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sterigmatocystin (ST) and aflatoxin B(1) (AFB(1)) are two polyketide-derived Aspergillus mycotoxins synthesized by functionally identical sets of enzymes. ST, the compound produced by Aspergillus nidulans, is a late intermediate in the AFB(1) pathway of A. parasiticus and A. flavus. Previous biochemical studies predicted that five oxygenase steps are required for the formation of ST. A 60-kb ST gene cluster in A. nidulans contains five genes, stcB, stcF, stcL, stcS, and stcW, encoding putative monooxygenase activities. Prior research showed that stcL and stcS mutants accumulated versicolorins B and A, respectively. We now show that strains disrupted at stcF, encoding a P-450 monooxygenase similar to A. parasiticus avnA, accumulate averantin. Disruption of either StcB (a putative P-450 monooxygenase) or StcW (a putative flavin-requiring monooxygenase) led to the accumulation of averufin as determined by radiolabeled feeding and extraction studies.
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Affiliation(s)
- N P Keller
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, Texas 77843, USA.
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31
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Butchko RA, Adams TH, Keller NP. Aspergillus nidulans mutants defective in stc gene cluster regulation. Genetics 1999; 153:715-20. [PMID: 10511551 PMCID: PMC1460771 DOI: 10.1093/genetics/153.2.715] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The genes involved in the biosynthesis of sterigmatocystin (ST), a toxic secondary metabolite produced by Aspergillus nidulans and an aflatoxin (AF) precursor in other Aspergillus spp., are clustered on chromosome IV of A. nidulans. The sterigmatocystin gene cluster (stc gene cluster) is regulated by the pathway-specific transcription factor aflR. The function of aflR appears to be conserved between ST- and AF-producing aspergilli, as are most of the other genes in the cluster. We describe a novel screen for detecting mutants defective in stc gene cluster activity by use of a genetic block early in the ST biosynthetic pathway that results in the accumulation of the first stable intermediate, norsolorinic acid (NOR), an orange-colored compound visible with the unaided eye. We have mutagenized this NOR-accumulating strain and have isolated 176 Nor(-) mutants, 83 of which appear to be wild type in growth and development. Sixty of these 83 mutations are linked to the stc gene cluster and are likely defects in aflR or known stc biosynthetic genes. Of the 23 mutations not linked to the stc gene cluster, 3 prevent accumulation of NOR due to the loss of aflR expression.
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Affiliation(s)
- R A Butchko
- Department of Plant Pathology, Texas A&M University, College Station, Texas 77843-2132, USA
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Abstract
Mycotoxins are secondary metabolites produced by many important phytopathogenic and food spoilage fungi including Aspergillus, Fusarium and Penicillium species. The toxicity of four of the most agriculturally important mycotoxins (the trichothecenes, and the polyketide-derived mycotoxins; aflatoxins, fumonisins and sterigmatocystin) are discussed and their chemical structure described. The steps involved in the biosynthesis of aflatoxin and sterigmatocystin and the experimental techniques used in the cloning and molecular characterisation of the genes involved in the pathway are described in detail. The biosynthetic genes involved in the fumonisin and trichothecene biosynthetic pathways are also outlined. The potential benefits gained from an increased knowledge of the molecular organisation of these pathways together with the mechanisms involved in their regulation are also discussed.
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Affiliation(s)
- M J Sweeney
- Microbiology Department, University College Cork, Ireland
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Brown MP, Brown-Jenco CS, Payne GA. Genetic and molecular analysis of aflatoxin biosynthesis. Fungal Genet Biol 1999; 26:81-98. [PMID: 10328980 DOI: 10.1006/fgbi.1998.1114] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- M P Brown
- InterLink Associates, 11930 Heritage Oak Place, Suite 4, Auburn, California 95603, USA
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34
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Woloshuk CP, Prieto R. Genetic organization and function of the aflatoxin B1 biosynthetic genes. FEMS Microbiol Lett 1998; 160:169-76. [PMID: 9532734 DOI: 10.1111/j.1574-6968.1998.tb12907.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Aflatoxins are secondary metabolites produced by Aspergillus flavus and Aspergillus parasiticus. Most of the genes involved in the biosynthesis of aflatoxin are contained within a single cluster in the genome of these filamentous fungi. Studies directed toward understanding the molecular biology of aflatoxin biosynthesis have led to a number of important discoveries. A pair of fatty acid synthase genes were identified that are involved uniquely in aflatoxin biosynthesis. Two genes were also characterized that represent new families of cytochrome P450 monooxygenases. Gene expression is coordinated during aflatoxin production and is under the control of a positive regulatory gene belonging to a family of fungal transcriptional activators associated with various metabolic pathways in fungi.
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Affiliation(s)
- C P Woloshuk
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
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35
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Payne GA, Brown MP. Genetics and physiology of aflatoxin biosynthesis. ANNUAL REVIEW OF PHYTOPATHOLOGY 1998; 36:329-62. [PMID: 15012504 DOI: 10.1146/annurev.phyto.36.1.329] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Aflatoxins are the most thoroughly studied mycotoxins. Elegant early research on the biosynthetic scheme of the pathway has allowed a molecular characterization of aflatoxin biosynthesis and its regulation. Genetic studies on aflatoxin biosynthesis in Aspergillus flavus and A. parasiticus, and sterigmatocystin biosynthesis in A. nidulans, led to the cloning of 17 genes responsible for 12 enzymatic conversions in the AF/ST pathways. Pathway-specific regulation is by a Zn(II)2Cys6 DNA-binding protein that regulates the transcription of all pathway genes. Less is known about the global factors that regulate aflatoxin biosynthesis, but there is a clear link between development and aflatoxin biosynthesis. There is also a large body of information on physiological factors involved in aflatoxin biosynthesis, but it has been difficult to understand their role in the regulation of this pathway. This chapter discusses current knowledge on the molecular biology and genetics of the pathway, and provides a summary of the physiological factors known to influence aflatoxin formation.
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Affiliation(s)
- G A Payne
- Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina 27695-7616, USA.
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36
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Minto RE, Townsend CA. Enzymology and Molecular Biology of Aflatoxin Biosynthesis. Chem Rev 1997; 97:2537-2556. [PMID: 11851470 DOI: 10.1021/cr960032y] [Citation(s) in RCA: 169] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert E. Minto
- Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218
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