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Xu J, Jiang M, Wang P, Kong Q. The Gene vepN Regulated by Global Regulatory Factor veA That Affects Aflatoxin Production, Morphological Development and Pathogenicity in Aspergillus flavus. Toxins (Basel) 2024; 16:174. [PMID: 38668599 PMCID: PMC11054512 DOI: 10.3390/toxins16040174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/02/2024] [Accepted: 03/26/2024] [Indexed: 04/29/2024] Open
Abstract
Velvet (VeA), a light-regulated protein that shuttles between the cytoplasm and the nucleus, serves as a key global regulator of secondary metabolism in various Aspergillus species and plays a pivotal role in controlling multiple developmental processes. The gene vepN was chosen for further investigation through CHIP-seq analysis due to significant alterations in its interaction with VeA under varying conditions. This gene (AFLA_006970) contains a Septin-type guanine nucleotide-binding (G) domain, which has not been previously reported in Aspergillus flavus (A. flavus). The functional role of vepN in A. flavus was elucidated through the creation of a gene knockout mutant and a gene overexpression strain using a well-established dual-crossover recombinational technique. A comparison between the wild type (WT) and the ΔvepN mutant revealed distinct differences in morphology, reproductive capacity, colonization efficiency, and aflatoxin production. The mutant displayed reduced growth rate; dispersion of conidial heads; impaired cell wall integrity; and decreased sclerotia formation, colonization capacity, and aflatoxin levels. Notably, ΔvepN exhibited complete growth inhibition under specific stress conditions, highlighting the essential role of vepN in A. flavus. This study provides evidence that vepN positively influences aflatoxin production, morphological development, and pathogenicity in A. flavus.
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Affiliation(s)
- Jia Xu
- School of Food Science and Engineering, Ocean University of China, Qingdao 266404, China; (J.X.); (M.J.)
| | - Mengqi Jiang
- School of Food Science and Engineering, Ocean University of China, Qingdao 266404, China; (J.X.); (M.J.)
| | - Peng Wang
- College of Marine Life Science, Ocean University of China, Qingdao 266003, China;
| | - Qing Kong
- School of Food Science and Engineering, Ocean University of China, Qingdao 266404, China; (J.X.); (M.J.)
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2
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Zhou S, Ismail MAI, Aimanianda V, de Hoog GS, Kang Y, Ahmed SA. Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis. Med Mycol 2024; 62:myae034. [PMID: 38578660 DOI: 10.1093/mmy/myae034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.
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Affiliation(s)
- Shaoqin Zhou
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
| | - Mawahib A I Ismail
- Mycology Reference Laboratory, University of Khartoum, 11115, Khartoum, Sudan
| | - Vishukumar Aimanianda
- Immunobiology of Aspergillus, Institut Pasteur, Universite ́ Paris Cite ́ 75015, Paris, France
| | - G Sybren de Hoog
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
| | - Yingqian Kang
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
| | - Sarah A Ahmed
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
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El-Dawy EGAM, Gherbawy YA, Hussein MA. Characterization of Aspergillus section Flavi associated with stored grains. Mycotoxin Res 2024; 40:187-202. [PMID: 38231446 PMCID: PMC10834605 DOI: 10.1007/s12550-023-00514-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/18/2024]
Abstract
Increased frequencies of Aspergillus section Flavi and aflatoxins in cereal grains have been seen in recent years due to changes in climate circumstances, such as high temperatures and drought. To assess the microbiological risks of contamination, it is critical to have a reliable and accurate means of identifying the fungi. The main goal of this study was to characterize Aspergillus species from section Flavi obtained from twenty-three samples of barley and maize grains, gathered from different markets in Qena, Egypt, using morphological and molecular techniques. Twenty-three isolates were chosen, one isolate from each sample; they were identified as A. aflatoxiformans (4 isolates), A. flavus (18), and A. parasiticus (1). The existence of four aflatoxin biosynthesis genes was also investigated in relation to the strains' ability to produce total aflatoxins and aflatoxin B1, focusing on the regulatory gene aflR and the structural genes aflD and aflM. All strains producing aflatoxins were linked to the presence of aflR1 and/or aflR2, except two isolates that exhibited aflatoxins but from which aflR1 or aflR2 were not detected, which may be due to one or more missing or unstudied additional genes involved in aflatoxin production. AflD and aflM genes were amplified by 10 and 9 isolates, respectively. Five samples of barley and maize were contaminated by aflatoxins. Fifteen isolates were positive for producing total aflatoxins in the range of 0.1-240 ppm. Antagonistic activity of Trichoderma viride against A. flavus (F5) was assessed at 31.3%. Trichoderma reduced total aflatoxins in all treated seeds, particularly those subjected to Trichoderma formulation.
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Affiliation(s)
- Eman G A M El-Dawy
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt.
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt.
| | - Youssuf A Gherbawy
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt
| | - Mohamed A Hussein
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt
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Chang PK. Creating large chromosomal segment deletions in Aspergillus flavus by a dual CRISPR/Cas9 system: Deletion of gene clusters for production of aflatoxin, cyclopiazonic acid, and ustiloxin B. Fungal Genet Biol 2024; 170:103863. [PMID: 38154756 DOI: 10.1016/j.fgb.2023.103863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 12/21/2023] [Accepted: 12/26/2023] [Indexed: 12/30/2023]
Abstract
Aspergillus flavus produces hepatocarcinogenic aflatoxin that adversely impacts human and animal health and international trade. A promising means to manage preharvest aflatoxin contamination of crops is biological control, which employs non-aflatoxigenic A. flavus isolates possessing defective aflatoxin gene clusters to outcompete field toxigenic populations. However, these isolates often produce other toxic metabolites. The CRISPR/Cas9 technology has greatly advanced genome editing and gene functional studies. Its use in deleting large chromosomal segments of filamentous fungi is rarely reported. A system of dual CRISPR/Cas9 combined with a 60-nucleotide donor DNA that allowed removal of A. flavus gene clusters involved in production of harmful specialized metabolites was established. It efficiently deleted a 102-kb segment containing both aflatoxin and cyclopiazonic acid gene clusters from toxigenic A. flavus morphotypes, L-type and S-type. It further deleted the 27-kb ustiloxin B gene cluster of a resulting L-type mutant. Overall efficiencies of deletion ranged from 66.6 % to 85.6 % and efficiencies of deletions repaired by a single copy of donor DNA ranged from 50.5 % to 72.7 %. To determine the capacity of this technique, a pigment-screening setup based on absence of aspergillic acid gene cluster was devised. Chromosomal segments of 201 kb and 301 kb were deleted with efficiencies of 57.7 % to 69.2 %, respectively. This system used natural A. flavus isolates as recipients, eliminated a forced-recycling step to produce recipients for next round deletion, and generated maker-free deletants with sequences predefined by donor DNA. The research provides a method for creating genuine atoxigenic biocontrol strains friendly for field trial release.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U. S. Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, LA 70124, United States.
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Bush DS, Calla B, Berenbaum MR. An Aspergillus flavus strain from bee bread of the Western honey bee ( Apis mellifera) displays adaptations to distinctive features of the hive environment. Ecol Evol 2024; 14:e10918. [PMID: 38389995 PMCID: PMC10883247 DOI: 10.1002/ece3.10918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 12/20/2023] [Accepted: 01/08/2024] [Indexed: 02/24/2024] Open
Abstract
Aspergillus fungi are ubiquitous inhabitants of colonies of the western honey bee (Apis mellifera), where they interact with bees in associations ranging from parasitism to possible mutualism. Aspergillus Flavi fungi are frequently found in bee bread (pollen processed for longterm storage) and are thought to contribute to food preparation, processing, preservation, and digestion. Conditions in the hive are challenging for fungi due, in part, to xeric and acidic properties of bee bread and the omnipresence of propolis, an antimicrobial product manufactured by bees from plant resins. We used quantitative and qualitative assays to determine whether A. flavus isolated from bee bread demonstrates tolerance for hive environmental conditions in terms of temperature, pH, osmotic pressure, and propolis exposure. Comparisons made use of three strains of A. flavus: a fungal biocontrol product not known from beehives (AF36), a strain isolated from bee bread (AFBB) in hives from central Illinois, and a pathogenic strain from a honey bee colony displaying symptoms of stonebrood (AFPA). Strain AFBB displayed higher tolerance of acidic conditions, low matric potential (simulating xeric substrate), and propolis exposure than did other strains. A genomic comparison between this new strain and the reference NRRL-3357 showed that AFBB, like AF36, might be blocked from carrying out aflatoxin biosynthesis. Sequence comparisons also revealed several missense variants in genes that encode proteins regulating osmotolerance and osmotic pressure in Aspergillus spp., including SakA, SskB, GfdA, and TcsB/Sln1. Collectively, results of our laboratory assays and genetic analyses are consistent with the suggestion that the strain isolated from bee bread is adapted to the bee bread environment and may have persisted due to a coevolutionary relationship between Aspergillus and A. mellifera. This finding bolsters recent concerns about the effects of fungicide use near bee colonies and broadens the ecological importance of highly adaptable fungal strains.
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Affiliation(s)
- Daniel S Bush
- Deparment of Entomology University of Illinois Urbana Illinois USA
| | - Bernarda Calla
- USDA-ARS Pacific Shellfish Research Unit Corvallis Oregon USA
| | - May R Berenbaum
- Deparment of Entomology University of Illinois Urbana Illinois USA
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Bharose AA, Hajare ST, Narayanrao DR, Gajera HG, Prajapati HK, Singh SC, Upadhye V. Whole genome sequencing and annotation of Aspergillus flavus JAM-JKB-B HA-GG20. Sci Rep 2024; 14:18. [PMID: 38168670 PMCID: PMC10762212 DOI: 10.1038/s41598-023-50986-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/28/2023] [Indexed: 01/05/2024] Open
Abstract
Groundnuts are mostly contaminated with the mold Aspergillus flavus which produces a carcinogenic mycotoxin called as aflatoxin. It is very important to understand the genetic factors underlying its pathogenicity, regulation, and biosynthesis of secondary metabolites and animal toxicities, but it still lacks useful information due to certain gaps in the era of modern technology. Therefore, the present study was considered to determine the key genes and metabolites involved in the biosynthesis of aflatoxin by using a molecular approach in a virulent strain of Aspergillus. The whole genome sequence of highly toxic and virulent Aspergillus isolates JAM-JKB-B HA-GG20 revealed 3,73,54,834 bp genome size, 2, 26, 257 number of contigs with N50 value of 49,272 bp, 12,400 genes and 48.1% of GC contained respectively. The genome sequence was compared with other known aflatoxin producing and non-producing genome of Aspergillus spp. and 61 secondary metabolite (SM) gene clusters were annotated with the toxic strain JAM-JKB-BHA-GG20 which showed similarity with other Aspergillus spp. A total number of eight genes (ver-1, AflR, pksA, uvm8, omt1, nor-1, Vha and aflP) were identified related to biosynthesis of aflatoxin and ochratoxin. Also, 69 SSR with forward and reverse primers and 137 di and tri nucleotide motifs were identified in the nucleotide sequence region related to aflatoxin gene pathway. The genes and putative metabolites identified in this study are potentially involved in host invasion and pathogenicity. As such, the genomic information obtained in this study is helpful in understanding aflatoxin gene producing pathway in comparison to other Aspergillus spp. and predicted presence of other secondary metabolites clusters viz. Nrps, T1pks etc. genes associated with a biosynthesis of OTA mycotoxin.
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Affiliation(s)
| | | | | | - H G Gajera
- Department of Biotechnology, College of Agriculture, Junagadh Agricultural University, Junagadh, 362001, Gujarat, India
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Moghadasi F, Roudbarmohammadi S, Amanloo S, Nikoomanesh F, Roudbary M. Evaluation of antifungal activity of natural compounds on growth and aflatoxin B1 production of Aspergillus parasiticus and Aspergillus flavus. Mol Biol Rep 2024; 51:53. [PMID: 38165494 DOI: 10.1007/s11033-023-09102-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/05/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND Aspergillus species cause broad spectrum infections especially invasive lethal infections in immunocompromised patients. This study aimed to assess the antifungal activity of plants and compounds including Aloe vera, Thyme, carvacrol, and nano-encapsulation of carvacrol on the growth and production of aflatoxin B1 production by Aspergillus parasiticus and Aspergillus flavus. METHODS AND RESULTS Minimum inhibitory concentrations of extracts Aloe vera, Thyme, carvacrol, and nanocarvacrol, and fluconazole as a control were determined according to Clinical and Laboratory Standards Institute by serial microdilution protocol. Then, the effect of inhibitory concentrations of these compounds on the aflatoxin B1 production level was evaluated by real-time PCR and high-performance liquid chromatography. Our results indicate that the Aspergillus parasiticus and Aspergillus flavusare sensitive to selected plants and compounds. CONCLUSION Our findings showed that the compounds are appropriate alternative candidates against growth and production of aflatoxin of Aspergillus spp.
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Affiliation(s)
- Fariba Moghadasi
- Department of Medical Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Shahla Roudbarmohammadi
- Department of Medical Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Saied Amanloo
- Departnent of Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Fatemeh Nikoomanesh
- Infectious Diseases Research Center, Birjand University of Medical Sciences, Birjand, Iran
| | - Maryam Roudbary
- Department of Parasitology and Mycology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Daniel-Ivad P, Ryan KS. Structure of methyltransferase RedM that forms the dimethylpyrrolinium of the bisindole reductasporine. J Biol Chem 2024; 300:105520. [PMID: 38042494 PMCID: PMC10784701 DOI: 10.1016/j.jbc.2023.105520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 12/04/2023] Open
Abstract
Bisindoles are biologically active natural products that arise from the oxidative dimerization of two molecules of l-tryptophan. In bacterial bisindole pathways, a core set of transformations is followed by the action of diverse tailoring enzymes that catalyze reactions that lead to diverse bisindole products. Among bisindoles, reductasporine is distinct due to its dimethylpyrrolinium structure. Its previously reported biosynthetic gene cluster encodes two unique tailoring enzymes, the imine reductase RedE and the dimethyltransferase RedM, which were shown to produce reductasporine from a common bisindole intermediate in recombinant E. coli. To gain more insight into the unique tailoring enzymes in reductasporine assembly, we reconstituted the biosynthetic pathway to reductasporine in vitro and then solved the 1.7 Å resolution structure of RedM. Our work reveals RedM adopts a variety of conformational changes with distinct open and closed conformations, and site-directed mutagenesis alongside sequence analysis identifies important active site residues. Finally, our work sets the stage for understanding how RedM evolved to react with a pyrrolinium scaffold and may enable the development of new dimethyltransferase catalysts.
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Affiliation(s)
- Phillip Daniel-Ivad
- Department of Chemistry, The University of British Columbia, Vancouver, Canada
| | - Katherine S Ryan
- Department of Chemistry, The University of British Columbia, Vancouver, Canada.
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Zhao Y, Zeng R, Chen P, Huang C, Xu K, Huang X, Wang X. Transcriptomic and Proteomic Insights into the Effect of Sterigmatocystin on Aspergillus flavus. J Fungi (Basel) 2023; 9:1193. [PMID: 38132793 PMCID: PMC10745003 DOI: 10.3390/jof9121193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 12/02/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
Aspergillus flavus is an important fungus that produces aflatoxins, among which aflatoxin B1 (AFB1) is the most toxic and contaminates food and poses a high risk to human health. AFB1 interacts with another mycotoxin sterigmatocystin (STC), which is also a precursor of AFB1. Herein, we determined the effect of STC on AFB1 by evaluating A. flavus transcriptomic and proteomic profiles in the presence or absence of STC by RNA-seq and isobaric tagging, respectively. Overall, 3377 differentially expressed genes were identified by RNA-seq. These genes were mainly associated with the cellular component organisation and biosynthesis, the synthesis of valine, leucine, and isoleucine, and the synthesis of aflatoxin. Clustered genes responsible for AFB1 biosynthesis exhibited varying degrees of downregulation, and norB expression was completely suppressed in the experimental group. During proteomic analysis, 331 genes were differentially expressed in response to STC. These differentially expressed proteins were associated with cell parts and catalytic and antioxidant activities. Differentially expressed proteins predominantly participated in metabolic pathways associated with aflatoxin biosynthesis, glycolysis/gluconeogenesis, glutathione metabolism, and carbon metabolism. Notably, the upregulated and downregulated enzymes in carbohydrate and glutathione metabolisms may serve as potential gateways for inhibiting aflatoxin biosynthesis. Moreover, twelve proteins including seven downregulated ones involved in aflatoxin biosynthesis were identified; among them, AflG was the most downregulated, suggesting that it may be the key enzyme responsible for inhibiting aflatoxin synthesis. These findings provide novel insights into A. flavus control and the mechanisms regulating mycotoxin production.
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Affiliation(s)
- Yarong Zhao
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Rui Zeng
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Peirong Chen
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Chulan Huang
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Kaihang Xu
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Xiaomei Huang
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
| | - Xu Wang
- Institute of Quality Standard and Monitoring Technology for Agro-Product of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.Z.); (R.Z.); (P.C.); (C.H.); (K.X.); (X.H.)
- Laboratory of Quality and Safety Risk Assessment for Agro-Product (Guangzhou), Ministry of Agriculture, Guangzhou 510640, China
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Karahoda B, Pfannenstiel BT, Sarikaya-Bayram Ö, Dong Z, Ho Wong K, Fleming AB, Keller NP, Bayram Ö. The KdmB-EcoA-RpdA-SntB (KERS) chromatin regulatory complex controls development, secondary metabolism and pathogenicity in Aspergillus flavus. Fungal Genet Biol 2023; 169:103836. [PMID: 37666447 PMCID: PMC10841535 DOI: 10.1016/j.fgb.2023.103836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 08/28/2023] [Accepted: 09/01/2023] [Indexed: 09/06/2023]
Abstract
The filamentous fungus Aspergillus flavus is a plant and human pathogen predominantly found in the soil as spores or sclerotia and is capable of producing various secondary metabolites (SM) such as the carcinogenic mycotoxin aflatoxin. Recently, we have discovered a novel nuclear chromatin binding complex (KERS) that contains the JARID1-type histone demethylase KdmB, a putative cohesion acetyl transferase EcoA, a class I type histone deacetylase RpdA and the PHD ring finger reader protein SntB in the model filamentous fungus Aspergillus nidulans. Here, we show the presence of the KERS complex in A. flavus by immunoprecipitation-coupled mass spectrometry and constructed kdmBΔ and rpdAΔ strains to study their roles in fungal development, SM production and histone post-translational modifications (HPTMs). We found that KdmB and RpdA couple the regulation of SM gene clusters with fungal light-responses and HPTMs. KdmB and RpdA have opposing roles in light-induced asexual conidiation, while both factors are positive regulators of sclerotia development through the nsdC and nsdD pathway. KdmB and RpdA are essential for the productions of aflatoxin (similar to findings for SntB) as well as cyclopiazonic acid, ditryptophenaline and leporin B through controlling the respective SM biosynthetic gene clusters. We further show that both KdmB and RpdA regulate H3K4me3 and H3K9me3 levels, while RpdA also acts on H3K14ac levels in nuclear extracts. Therefore, the chromatin modifiers KdmB and RpdA of the KERS complex are key regulators for fungal development and SM metabolism in A. flavus.
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Affiliation(s)
- Betim Karahoda
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Brandon T Pfannenstiel
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, USA
| | | | - Zhiqiang Dong
- Faculty of Health Sciences, University of Macau, Macau
| | - Koon Ho Wong
- Faculty of Health Sciences, University of Macau, Macau; Institute of Translational Medicine, University of Macau, Macau; Ministry of Education Frontiers Science Center for Precision Oncology, University of Macau, Macau
| | - Alastair B Fleming
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, USA
| | - Özgür Bayram
- Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland.
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Zhu Z, Yang M, Yang G, Zhang B, Cao X, Yuan J, Ge F, Wang S. PP2C phosphatases Ptc1 and Ptc2 dephosphorylate PGK1 to regulate autophagy and aflatoxin synthesis in the pathogenic fungus Aspergillus flavus. mBio 2023; 14:e0097723. [PMID: 37754565 PMCID: PMC10653812 DOI: 10.1128/mbio.00977-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/08/2023] [Indexed: 09/28/2023] Open
Abstract
IMPORTANCE Aspergillus flavus is a model filamentous fungus that can produce aflatoxins when it infects agricultural crops. This study evaluated the protein phosphatase 2C (PP2C) family as a potential drug target with important physiological functions and pathological significance in A. flavus. We found that two redundant PP2C phosphatases, Ptc1 and Ptc2, regulate conidia development, aflatoxin synthesis, autophagic vesicle formation, and seed infection. The target protein phosphoglycerate kinase 1 (PGK1) that interacts with Ptc1 and Ptc2 is essential to regulate metabolism and the autophagy process. Furthermore, Ptc1 and Ptc2 regulate the phosphorylation level of PGK1 S203, which is important for influencing aflatoxin synthesis. Our results provide a potential target for interdicting the toxicity of A. flavus.
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Affiliation(s)
- Zhuo Zhu
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
- Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mingkun Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Guang Yang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Bei Zhang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaohong Cao
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jun Yuan
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Shihua Wang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, Key Laboratory of Pathogenic Fungi, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
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Rajput A, Manna T, Husain SM. Anthrol reductases: discovery, role in biosynthesis and applications in natural product syntheses. Nat Prod Rep 2023; 40:1672-1686. [PMID: 37475701 DOI: 10.1039/d3np00027c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Covering: up to 2023Short-chain dehydrogenase/reductases (SDR) are known to catalyze the regio- and stereoselective reduction of a variety of substrate types. Investigations of the deoxygenation of emodin to chrysophanol has led to the discovery of the anthrol reductase activity of an SDR, MdpC involved in monodictyphenone biosynthesis of Aspergillus nidulans and provided access to (R)-dihydroanthracenone, a putative biosynthetic intermediate. This facilitated the identification of several MdpC-related enzymes involved in the biosynthesis of aflatoxins B1, cladofulvin, neosartorin, agnestins and bisanthraquinones. Because of their ability to catalyze the reduction of hydroanthraquinone (anthrols) using NADPH, they were named anthrol reductases. This review provides a comprehensive summary of all the anthrol reductases that have been identified and characterized in the last decade along with their role in the biosynthesis of natural products. In addition, the applications of these enzymes towards the chemoenzymatic synthesis of flavoskyrins, modified bisanthraquinones, 3-deoxy anthraquinones, chiral cycloketones and β-halohydrins have been discussed.
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Affiliation(s)
- Anshul Rajput
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow 226014, India.
| | - Tanaya Manna
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow 226014, India.
| | - Syed Masood Husain
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS Campus, Raebareli Road, Lucknow 226014, India.
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13
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Qiu M, Qiu L, Deng Q, Fang Z, Sun L, Wang Y, Gooneratne R, Zhao J. L-Cysteine hydrochloride inhibits Aspergillus flavus growth and AFB 1 synthesis by disrupting cell structure and antioxidant system balance. J Hazard Mater 2023; 459:132218. [PMID: 37552922 DOI: 10.1016/j.jhazmat.2023.132218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/26/2023] [Accepted: 08/02/2023] [Indexed: 08/10/2023]
Abstract
Aflatoxin B1 (AFB1) is the most potent known naturally occurring carcinogen and pose an immense threat to food safety and human health. L-Cysteine hydrochloride (L-CH) is a food additive often used as a fruit and vegetable preservative and also to approved bread consistency. In this study, we investigated the effects and mechanisms of L-CH as an antimicrobial on the growth of Aspergillus flavus (A. flavus) and AFB1 biosynthesis. L-CH significantly inhibited A. flavus mycelial growth, affected mycelial morphology and AFB1 synthesis. Furthermore, L-CH induced glutathione (GSH) synthesis which scavenged intracellular reactive oxygen species (ROS). RNA-Seq indicated that L-CH inhibited hyphal branching, and spore and sclerotia formation by controlling cell wall and spore development-related genes. Activation of the GSH metabolic pathway eliminated intracellular ROS, leading to hyphal dwarfing. L-CH treatment downregulated most of the Aflatoxin (AF) cluster genes and aflS, aflR, AFLA_091090 transcription factors. This study provides new insights into the molecular mechanism of L-CH control of A. flavus and AFB1 foundation. We believe that L-CH could be used as a food additive to control AFB1 in foods and also in the environment.
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Affiliation(s)
- Mei Qiu
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China
| | - Lihong Qiu
- Department of Clinical Laboratory, Affiliated Hospital of Guangdong Medical University, Zhanjiang 524001, China
| | - Qi Deng
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China.
| | - Zhijia Fang
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China
| | - Lijun Sun
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China
| | - Yaling Wang
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Key Laboratory of Advanced Processing of Aquatic Products of Guangdong Higher Education Institution, Zhanjiang 524088, China
| | - Ravi Gooneratne
- Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture and Life Sciences, Lincoln University, Lincoln 7647, New Zealand
| | - Jian Zhao
- School of Chemical Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
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Liu L, Wang B, Duan G, Wang J, Pan Z, Ou M, Bai X, Wang P, Zhao D, Nan N, Li D, Sun W. Histone Deacetylase UvHST2 Is a Global Regulator of Secondary Metabolism in Ustilaginoidea virens. J Agric Food Chem 2023; 71:13124-13136. [PMID: 37615365 DOI: 10.1021/acs.jafc.3c01782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Abstract
Ustilaginoidea virens, the causal agent of rice false smut, produces a large amount of mycotoxins, including ustilaginoidins and sorbicillinoids. However, little is known about the regulatory mechanism of mycotoxin biosynthesis inU. virens. Here, we demonstrate that the NAD+-dependent histone deacetylase UvHST2 negatively regulates ustilaginoidin biosynthesis. UvHst2 knockout caused retarded hypha growth and reduced conidiation and pathogenicity inU. virens. Transcriptome analysis revealed that the transcription factor genes, transporter genes, and other tailoring genes in eight biosynthetic gene clusters (BGCs) including ustilaginoidin and sorbicillinoid BGCs were upregulated in ΔUvhst2. Interestingly, the UvHst2 deletion affects alternative splicing. Metabolomics revealed that UvHST2 negatively regulates the biosynthesis of various mycotoxins including ustilaginoidins, sorbicillin, ochratoxin B, zearalenone, and O-M-sterigmatocystin. Combined transcriptome and metabolome analyses uncover that UvHST2 positively regulates pathogenicity but negatively modulates the expression of BGCs involved in secondary metabolism. Collectively, UvHST2 functions as a global regulator of secondary metabolism inU. virens.
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Affiliation(s)
- Ling Liu
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Bo Wang
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Guohua Duan
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Jing Wang
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Zequn Pan
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Mingming Ou
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Xiaolong Bai
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Peiying Wang
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Dan Zhao
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Nan Nan
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Dayong Li
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
| | - Wenxian Sun
- College of Plant Protection, Jilin Provincial Key Laboratory of Green Management of Crop Pests and Diseases, Jilin Agricultural University, 2888 Xincheng Street, Changchun 130118, Jilin, China
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
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15
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Rassbach J, Hilsberg N, Haensch VG, Dörner S, Gressler J, Sonnabend R, Semm C, Voigt K, Hertweck C, Gressler M. Non-canonical two-step biosynthesis of anti-oomycete indole alkaloids in Kickxellales. Fungal Biol Biotechnol 2023; 10:19. [PMID: 37670394 PMCID: PMC10478498 DOI: 10.1186/s40694-023-00166-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/06/2023] [Indexed: 09/07/2023] Open
Abstract
BACKGROUND Fungi are prolific producers of bioactive small molecules of pharmaceutical or agricultural interest. The secondary metabolism of higher fungi (Dikarya) has been well-investigated which led to > 39,000 described compounds. However, natural product researchers scarcely drew attention to early-diverging fungi (Mucoro- and Zoopagomycota) as they are considered to rarely produce secondary metabolites. Indeed, only 15 compounds have as yet been isolated from the entire phylum of the Zoopagomycota. RESULTS Here, we showcase eight species of the order Kickxellales (phylum Zoopagomycota) as potent producers of the indole-3-acetic acid (IAA)-derived compounds lindolins A and B. The compounds are produced both under laboratory conditions and in the natural soil habitat suggesting a specialized ecological function. Indeed, lindolin A is a selective agent against plant-pathogenic oomycetes such as Phytophthora sp. Lindolin biosynthesis was reconstituted in vitro and relies on the activity of two enzymes of dissimilar evolutionary origin: Whilst the IAA-CoA ligase LinA has evolved from fungal 4-coumaryl-CoA synthetases, the subsequently acting IAA-CoA:anthranilate N-indole-3-acetyltransferase LinB is a unique enzyme across all kingdoms of life. CONCLUSIONS This is the first report on bioactive secondary metabolites in the subphylum Kickxellomycotina and the first evidence for a non-clustered, two-step biosynthetic route of secondary metabolites in early-diverging fungi. Thus, the generally accepted "gene cluster hypothesis" for natural products needs to be reconsidered for early diverging fungi.
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Affiliation(s)
- Johannes Rassbach
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Nathalie Hilsberg
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Veit G Haensch
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Adolf-Reichwein-Strasse 23, 07745, Jena, Germany
| | - Sebastian Dörner
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Julia Gressler
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Robin Sonnabend
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Caroline Semm
- Faculty of Biological Sciences, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 25, 07743, Jena, Germany
- Jena Microbial Resource Collection (JMRC), Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Adolf-Reichwein-Strasse 23, 07745, Jena, Germany
| | - Kerstin Voigt
- Faculty of Biological Sciences, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 25, 07743, Jena, Germany
- Jena Microbial Resource Collection (JMRC), Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute, Adolf-Reichwein-Strasse 23, 07745, Jena, Germany
| | - Christian Hertweck
- Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Adolf-Reichwein-Strasse 23, 07745, Jena, Germany
- Faculty of Biological Sciences, Institute of Microbiology, Friedrich Schiller University Jena, Neugasse 25, 07743, Jena, Germany
| | - Markus Gressler
- Faculty of Biological Sciences, Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany.
- Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans-Knöll-Institute, Winzerlaer Strasse 2, 07745, Jena, Germany.
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Daliri A, Shams-Ghahfarokhi M, Razzaghi-Abyaneh M. Detection of Aflatoxin B1-producing Aspergillus flavus strains from pistachio orchards soil in Iran by multiplex polymerase chain reaction method. Curr Med Mycol 2023; 9:1-7. [PMID: 38361961 PMCID: PMC10864740 DOI: 10.22034/cmm.2023.345055.1420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 11/13/2023] [Accepted: 11/14/2023] [Indexed: 02/17/2024] Open
Abstract
Background and Purpose The current study aimed to report a multiplex polymerase chain reaction (PCR) assay as a monitoring technique to differentiate aflatoxigenic from non-aflatoxigenic strains of Aspergillus flavus isolated from pistachio orchards soil. Materials and Methods In total, 25 A. flavus strains were isolated from soil samples of pistachio orchards. To test the strains for Aflatoxin B1 (AFB1)-producing ability, thin-layer chromatography (TLC) was used and the amounts of AFB1 were measured by high-performance liquid chromatography (HPLC). Multiplex PCR was used as a genome-based method to detect genes responsible for AFB1 production by A. flavus and the results were analyzed in terms of speed and specificity of detection. A set of four primers was designed specifically for the omtA, omtB, ver-1, and aflR genes which are commonly present in aflatoxin biosynthetic pathways. Results The AFB1 production by the A. flavus strains ranged from 0 to 321 ρg/μl. Four-band patterns of the primer sets were observed only in AFB1-producing A. flavus strains. Moreover, 18 out of the 25 strains showed all four bands belonging to omtA, omtB, ver-1, and aflR, whereas 7 strains did not display omtA, or aflR-related bands, in non-toxigenic and low toxin-producing A. flavus. Conclusion The multiplex PCR is a supplementary strategy to current conventional mycotoxin analytical techniques, such as TLC and HPLC. It could be used as an efficient method to differentiate aflatoxigenic from non-aflatoxigenic strains of A. flavus. This achievement is crucial to minimize fungal contamination of food, feed, and agricultural commodities, thereby reducing the risk of subsequent aflatoxin consumption.
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Affiliation(s)
- Amin Daliri
- Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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17
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Legan AW, Mack BM, Mehl HL, Wissotski M, Ching’anda C, Maxwell LA, Callicott KA. Complete genome of the toxic mold Aspergillus pseudotamarii isolate NRRL 25517 reveals genomic instability of the aflatoxin biosynthesis cluster. G3 (Bethesda) 2023; 13:jkad150. [PMID: 37401423 PMCID: PMC10468309 DOI: 10.1093/g3journal/jkad150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 04/24/2023] [Accepted: 06/21/2023] [Indexed: 07/05/2023]
Abstract
Fungi can synthesize a broad array of secondary metabolite chemicals. The genes underpinning their biosynthesis are typically arranged in tightly linked clusters in the genome. For example, ∼25 genes responsible for the biosynthesis of carcinogenic aflatoxins by Aspergillus section Flavi species are grouped in a ∼70 Kb cluster. Assembly fragmentation prevents assessment of the role of structural genomic variation in secondary metabolite evolution in this clade. More comprehensive analyses of secondary metabolite evolution will be possible by working with more complete and accurate genomes of taxonomically diverse Aspergillus species. Here, we combined short- and long-read DNA sequencing to generate a highly contiguous genome of the aflatoxigenic fungus, Aspergillus pseudotamarii (isolate NRRL 25517 = CBS 766.97; scaffold N50 = 5.5 Mb). The nuclear genome is 39.4 Mb, encompassing 12,639 putative protein-encoding genes and 74-97 candidate secondary metabolite biosynthesis gene clusters. The circular mitogenome is 29.7 Kb and contains 14 protein-encoding genes that are highly conserved across the genus. This highly contiguous A. pseudotamarii genome assembly enables comparisons of genomic rearrangements between Aspergillus section Flavi series Kitamyces and series Flavi. Although the aflatoxin biosynthesis gene cluster of A. pseudotamarii is conserved with Aspergillus flavus, the cluster has an inverted orientation relative to the telomere and occurs on a different chromosome.
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Affiliation(s)
- Andrew W Legan
- US Department of Agriculture, Arid Land Agricultural Research Center, Tucson, AZ 85701, USA
| | - Brian M Mack
- US Department of Agriculture, Food and Feed Safety Research Unit, New Orleans, LA 70124, USA
| | - Hillary L Mehl
- US Department of Agriculture, Arid Land Agricultural Research Center, Tucson, AZ 85701, USA
| | - Marina Wissotski
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Connel Ching’anda
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Lourena A Maxwell
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Kenneth A Callicott
- US Department of Agriculture, Arid Land Agricultural Research Center, Tucson, AZ 85701, USA
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Liang L, Zhang W, Hao J, Wang Y, Wei S, Zhang S, Hu Y, Lv Y. Estragole Inhibits Growth and Aflatoxin Biosynthesis of Aspergillus flavus by Affecting Reactive Oxygen Species Homeostasis. Microbiol Spectr 2023; 11:e0134823. [PMID: 37289093 PMCID: PMC10434025 DOI: 10.1128/spectrum.01348-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 05/21/2023] [Indexed: 06/09/2023] Open
Abstract
A variety of essential oils and edible compounds have been widely recognized for their antifungal activity in recent years. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against Aspergillus flavus and investigated the underlying mechanism of action. The results showed that estragole had significant antifungal activity against A. flavus, with a minimum inhibitory concentration of 0.5 μL/mL against spore germination. Additionally, estragole inhibited the biosynthesis of aflatoxin in a dose-dependent manner, and aflatoxin biosynthesis was significantly inhibited at 0.125 μL/mL. Pathogenicity assays showed that estragole had potential antifungal activity against A. flavus in peanut and corn grains by inhibiting conidia and aflatoxin production. Transcriptomic analysis showed that the differentially expressed genes (DEGs) were mainly related to oxidative stress, energy metabolism, and secondary metabolite synthesis following estragole treatment. Importantly, we experimentally verified reactive oxidative species accumulation following downregulation of antioxidant enzymes, including catalase, superoxide dismutase, and peroxidase. These results suggest that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis. These findings expand our knowledge on the antifungal activity and molecular mechanisms of estragole, and provide a basis for estragole as a potential agent against A. flavus contamination. IMPORTANCE Aspergillus flavus contaminates crops and produces aflatoxins, carcinogenic secondary metabolites which pose a serious threat to agricultural production and animal and human health. Currently, control of A. flavus growth and mycotoxin contamination mainly relies on antimicrobial chemicals, agents with side effects such as toxic residues and the emergence of resistance. With their safety, environmental friendliness, and high efficiency, essential oils and edible compounds have become promising antifungal agents to control growth and mycotoxin biosynthesis in hazardous filamentous fungi. In this study, we explored the antifungal activity of estragole from Pimenta racemosa against A. flavus and investigated its underlying mechanism. The results demonstrated that estragole inhibits the growth and aflatoxin biosynthesis of A. flavus by modulating intracellular redox homeostasis.
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Affiliation(s)
- Liuke Liang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Wei Zhang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Jing Hao
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Yanyu Wang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Shan Wei
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Shuaibing Zhang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Yuansen Hu
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
| | - Yangyong Lv
- College of Biological Engineering, Henan University of Technology, Zhengzhou, China
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Löhr NA, Rakhmanov M, Wurlitzer JM, Lackner G, Gressler M, Hoffmeister D. Basidiomycete non-reducing polyketide synthases function independently of SAT domains. Fungal Biol Biotechnol 2023; 10:17. [PMID: 37542286 PMCID: PMC10401856 DOI: 10.1186/s40694-023-00164-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 07/16/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Non-reducing polyketide synthases (NR-PKSs) account for a major share of natural product diversity produced by both Asco- and Basidiomycota. The present evolutionary diversification into eleven clades further underscores the relevance of these multi-domain enzymes. Following current knowledge, NR-PKSs initiate polyketide assembly by an N-terminal starter unit:acyl transferase (SAT) domain that catalyzes the transfer of an acetyl starter from the acetyl-CoA thioester onto the acyl carrier protein (ACP). RESULTS A comprehensive phylogenetic analysis of NR-PKSs established a twelfth clade from which three representatives, enzymes CrPKS1-3 of the webcap mushroom Cortinarius rufoolivaceus, were biochemically characterized. These basidiomycete synthases lack a SAT domain yet are fully functional hepta- and octaketide synthases in vivo. Three members of the other clade of basidiomycete NR-PKSs (clade VIII) were produced as SAT-domainless versions and analyzed in vivo and in vitro. They retained full activity, thus corroborating the notion that the SAT domain is dispensable for many basidiomycete NR-PKSs. For comparison, the ascomycete octaketide synthase atrochrysone carboxylic acid synthase (ACAS) was produced as a SAT-domainless enzyme as well, but turned out completely inactive. However, a literature survey revealed that some NR-PKSs of ascomycetes carry mutations within the catalytic motif of the SAT domain. In these cases, the role of the domain and the origin of the formal acetate unit remains open. CONCLUSIONS The role of SAT domains differs between asco- and basidiomycete NR-PKSs. For the latter, it is not part of the minimal set of NR-PKS domains and not required for function. This knowledge may help engineer compact NR-PKSs for more resource-efficient routes. From the genomic standpoint, seemingly incomplete or corrupted genes encoding SAT-domainless NR-PKSs should not automatically be dismissed as non-functional pseudogenes, but considered during genome analysis to decipher the potential arsenal of natural products of a given fungus.
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Affiliation(s)
- Nikolai A Löhr
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Malik Rakhmanov
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Jacob M Wurlitzer
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Gerald Lackner
- Synthetic Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Markus Gressler
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany
| | - Dirk Hoffmeister
- Institute of Pharmacy, Department Pharmaceutical Microbiology, Friedrich Schiller University Jena, Winzerlaer Strasse 2, 07745, Jena, Germany.
- Department Pharmaceutical Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute, Winzerlaer Strasse 2, 07745, Jena, Germany.
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20
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Yang F, Zhang L, Zhang Y, Zeng Y, Li Y, Zeng P. Culture-dependent and culture-independent approaches to reveal the aflatoxin B1-producing fungi in Pixian Doubanjiang, a typical condiment in Chinese cuisine. Food Control 2023. [DOI: 10.1016/j.foodcont.2023.109711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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21
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Chang PK, Hua SST. Are Current Aspergillus sojae Strains Originated from a Native Aflatoxigenic Aspergillus Species Population Also Present in California? Mycobiology 2023; 51:139-147. [PMID: 37359951 PMCID: PMC10288891 DOI: 10.1080/12298093.2023.2217495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/18/2023] [Accepted: 05/19/2023] [Indexed: 06/28/2023]
Abstract
Aspergillus sojae has long been considered a domesticated strain of Aspergillus parasiticus. This study delineated relationships among the two species and an Aspergillus PWE36 isolate. Of 25 examined clustered aflatoxin genes of PWE36, 20 gene sequences were identical to those of A. sojae, but all had variations to those of A. parasiticus. Additionally, PWE36 developmental genes of conidiation and sclerotial formation, overall, shared higher degrees of nucleotide sequence identity with A. sojae genes than with A. parasiticus genes. Examination of defective cyclopiazonic acid gene clusters revealed that the PWE36 deletion pattern was identical only to those of A. sojae. Using A. sojae SMF134 genome sequence as a reference, visualization of locally collinear blocks indicated that PWE36 shared higher genome sequence homologies with A. sojae than with A. parasiticus. Phylogenetic inference based on genome-wide single nucleotide polymorphisms (SNPs) and total SNP counts showed that A. sojae strains formed a monophyletic clade and were clonal. Two (Argentinian and Ugandan) A. parasiticus isolates but not including an Ethiopian isolate formed a monophyletic clade, which showed that A. parasiticus population is genetically diverse and distant to A. sojae. PWE36 and A. sojae shared a most recent common ancestor (MRCA). The estimated divergence time for PWE36 and A. sojae was about 0.4 mya. Unlike Aspergillus oryzae, another koji mold that includes genetically diverse populations, the findings that current A. sojae strains formed a monophyletic group and shared the MRCA with PWE36 allow A. sojae to be continuously treated as a species for food safety reasons.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA, USA
| | - Sui Sheng T. Hua
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA, USA
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22
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Mund NK, Čellárová E. Recent advances in the identification of biosynthetic genes and gene clusters of the polyketide-derived pathways for anthraquinone biosynthesis and biotechnological applications. Biotechnol Adv 2023; 63:108104. [PMID: 36716800 DOI: 10.1016/j.biotechadv.2023.108104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/27/2022] [Accepted: 01/23/2023] [Indexed: 01/28/2023]
Abstract
Natural anthraquinones are represented by a large group of compounds. Some of them are widespread across the kingdoms, especially in bacteria, fungi and plants, while the others are restricted to certain groups of organisms. Despite the significant pharmacological potential of several anthraquinones (hypericin, skyrin and emodin), their biosynthetic pathways and candidate genes coding for key enzymes have not been experimentally validated. Understanding the genetic and epigenetic regulation of the anthraquinone biosynthetic gene clusters in fungal endophytes would help not only understand their pathways in plants, which ensure their commercial availability, but also favor them as promising systems for prospective biotechnological production.
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Affiliation(s)
- Nitesh Kumar Mund
- Pavol Jozef Šafárik University in Košice, Faculty of Science, Institute of Biology and Ecology, Department of Genetics, Mánesova 23, 041 54 Košice, Slovakia
| | - Eva Čellárová
- Pavol Jozef Šafárik University in Košice, Faculty of Science, Institute of Biology and Ecology, Department of Genetics, Mánesova 23, 041 54 Košice, Slovakia.
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23
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Park SE, Kim JC, Im Y, Kim JS. Pathogenesis and defense mechanism while Beauveria bassiana JEF-410 infects poultry red mite, Dermanyssus gallinae. PLoS One 2023; 18:e0280410. [PMID: 36800366 PMCID: PMC9937463 DOI: 10.1371/journal.pone.0280410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/28/2022] [Indexed: 02/18/2023] Open
Abstract
The poultry red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae), is a major pest that causes great damage to chicken egg production. In one of our previous studies, the management of red mites using entomopathogenic fungi was evaluated, and the acaricidal fungus Beauveria bassiana JEF-410 was selected for further research. In this study, we tried to elucidate the pathogenesis of B. bassiana JEF-410 and the defense mechanisms of red mites at a transcriptome level. Red mites collected from a chicken farm were treated with B. bassiana JEF-410. When the mortality of infected red mites reached 50%, transcriptome analyses were performed to determine the interaction between B. bassiana JEF-410 and red mites. Uninfected red mites and non-infecting fungus served as controls. In B. bassiana JEF-410, up-regulated gene expression was observed in tryptophan metabolism and secondary metabolite biosynthesis pathways. Genes related to acetyl-CoA synthesis were up-regulated in tryptophan metabolism, suggesting that energy metabolism and stress management were strongly activated. Secondary metabolites associated with fungal up-regulated DEGs were related to the production of substances toxic to insects such as beauvericin and beauveriolide, efflux pump of metabolites, energy production, and resistance to stress. In red mites, physical and immune responses that strengthen the cuticle against fungal infection were highly up-regulated. From these gene expression analyses, we identified essential factors for fungal infection and subsequent defenses of red mites. These results will serve as a strong platform for explaining the interaction between B. bassiana JEF-410 and red mites in the stage of active infection.
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Affiliation(s)
- So Eun Park
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Jeonbuk National University, Jeonju, Korea
| | - Jong-Cheol Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Jeonbuk National University, Jeonju, Korea
| | - Yeram Im
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Jeonbuk National University, Jeonju, Korea
| | - Jae Su Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Jeonbuk National University, Jeonju, Korea
- Department of Agricultural Convergence Technology, Jeonbuk National University, Jeonju, Korea
- * E-mail:
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24
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de Mattos-Shipley KMJ, Simpson TJ. The 'emodin family' of fungal natural products-amalgamating a century of research with recent genomics-based advances. Nat Prod Rep 2023; 40:174-201. [PMID: 36222427 PMCID: PMC9890505 DOI: 10.1039/d2np00040g] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Indexed: 11/06/2022]
Abstract
Covering: up to 2022A very large group of biosynthetically linked fungal secondary metabolites are formed via the key intermediate emodin and its corresponding anthrone. The group includes anthraquinones such as chrysophanol and cladofulvin, the grisandienes geodin and trypacidin, the diphenyl ether pestheic acid, benzophenones such as monodictyphenone and various xanthones including the prenylated shamixanthones, the agnestins and dimeric xanthones such as the ergochromes, cryptosporioptides and neosartorin. Such compounds exhibit a wide range of bioactivities and as such have been utilised in traditional medicine for centuries, as well as garnering more recent interest from the pharmaceutical sector. Additional interest comes from industries such as textiles and cosmetics due to their use as natural colourants. A variety of biosynthetic routes and mechanisms have been proposed for this family of compounds, being altered and updated as new biosynthetic methods develop and new results emerge. After nearly 100 years of such research, this review aims to provide a comprehensive overview of what is currently known about the biosynthesis of this important family, amalgamating the early chemical and biosynthetic studies with the more recent genetics-based advances and comparative bioinformatics.
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Affiliation(s)
| | - Thomas J Simpson
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
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25
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Furukawa T, Kushiro M, Nakagawa H, Enomoto H, Sakuda S. Low-dose ethanol increases aflatoxin production due to the adh1-dependent incorporation of ethanol into aflatoxin biosynthesis. iScience 2023; 26:106051. [PMID: 36818304 PMCID: PMC9932502 DOI: 10.1016/j.isci.2023.106051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 12/09/2022] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
Aflatoxins are toxic secondary metabolites produced by some aspergilli, including Aspergillus flavus. Recently, ethanol has attracted attention as an agent for the control of aflatoxin contamination. However, as aflatoxin biosynthesis utilizes acetyl coenzyme A, ethanol may be conversely exploited for aflatoxin production. Here, we demonstrated that not only the 13C of labeled ethanol, but also that of labeled 2-propanol, was incorporated into aflatoxin B1 and B2, and that ethanol and 2-propanol upregulated aflatoxin production at low concentrations (<1% and <0.6%, respectively). In the alcohol dehydrogenase gene adh1 deletion mutant, the 13C incorporation of labeled ethanol, but not labeled 2-propanol, into aflatoxin B1 and B2 was attenuated, indicating that the alcohols have different utilization pathways. Our results show that A. flavus utilizes ethanol and 2-propanol as carbon sources for aflatoxin biosynthesis and that adh1 indirectly controls aflatoxin production by balancing ethanol production and catabolism.
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Affiliation(s)
- Tomohiro Furukawa
- Institute of Food Research, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan,Corresponding author
| | - Masayo Kushiro
- Institute of Food Research, National Agriculture and Food Research Organization (NARO), 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan
| | - Hiroyuki Nakagawa
- Research Center for Advanced Analysis, NARO, 2-1-12 Kannon-dai, Tsukuba-shi, Ibaraki 305-8642, Japan
| | - Hirofumi Enomoto
- Department of Biosciences, Faculty of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan,Advanced Instrumental Analysis Center, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan
| | - Shohei Sakuda
- Department of Biosciences, Faculty of Science and Engineering, Teikyo University, 1-1 Toyosatodai, Utsunomiya-shi, Tochigi 320-8551, Japan
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26
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Loi M, Logrieco AF, Pusztahelyi T, Leiter É, Hornok L, Pócsi I. Advanced mycotoxin control and decontamination techniques in view of an increased aflatoxin risk in Europe due to climate change. Front Microbiol 2023; 13:1085891. [PMID: 36762096 PMCID: PMC9907446 DOI: 10.3389/fmicb.2022.1085891] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/15/2022] [Indexed: 01/11/2023] Open
Abstract
Aflatoxins are toxic secondary metabolites produced by Aspergillus spp. found in staple food and feed commodities worldwide. Aflatoxins are carcinogenic, teratogenic, and mutagenic, and pose a serious threat to the health of both humans and animals. The global economy and trade are significantly affected as well. Various models and datasets related to aflatoxins in maize have been developed and used but have not yet been linked. The prevention of crop loss due to aflatoxin contamination is complex and challenging. Hence, the set-up of advanced decontamination is crucial to cope with the challenge of climate change, growing population, unstable political scenarios, and food security problems also in European countries. After harvest, decontamination methods can be applied during transport, storage, or processing, but their application for aflatoxin reduction is still limited. Therefore, this review aims to investigate the effects of environmental factors on aflatoxin production because of climate change and to critically discuss the present-day and novel decontamination techniques to unravel gaps and limitations to propose them as a tool to tackle an increased aflatoxin risk in Europe.
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Affiliation(s)
- Martina Loi
- Institute of Sciences of Food Production, National Research Council, Bari, Italy,*Correspondence: Martina Loi, ✉
| | - Antonio F. Logrieco
- Institute of Sciences of Food Production, National Research Council, Bari, Italy
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Éva Leiter
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, Institute of Biotechnology, University of Debrecen, Debrecen, Hungary,ELRN-UD Fungal Stress Biology Research Group, University of Debrecen, Debrecen, Hungary
| | - László Hornok
- Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Faculty of Science and Technology, Institute of Biotechnology, University of Debrecen, Debrecen, Hungary,ELRN-UD Fungal Stress Biology Research Group, University of Debrecen, Debrecen, Hungary
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27
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Niu A, Wu H, Hu X, Tan S, Wu Y, Yin X, Chen Y, Sun X, Wang G, Qiu W. New insights into the persistent effect of transient cinnamaldehyde vapor treatment on the growth and aflatoxin synthesis of Aspergillus flavus. Food Res Int 2023; 163:112300. [PMID: 36596201 DOI: 10.1016/j.foodres.2022.112300] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/26/2022] [Accepted: 12/03/2022] [Indexed: 12/13/2022]
Abstract
The antimicrobial effects of continuous treatment with essential oils (EOs) in both liquid and gaseous phases have been intensively studied. Due to their rapid volatility, the effects of EOs on microorganisms after transient treatment are also worth exploring. In this work, the persistent effects of cinnamaldehyde (CA) vapor on Aspergillus flavus were detected by a series of biochemical analyses. Transcriptome analysis was also conducted to study the gene expression changes between recovered and normal A. flavus. When CA vapor was removed, biochemical analyses showed that the oxidative stress induced by the antimicrobial atmosphere was alleviated, and almost all the damaged functions were restored apart from mitochondrial function. Remarkably, the suppressed aflatoxin production intensified, which was confirmed by the up-regulation of most genes in the aflatoxin synthetic gene cluster, the velvet-related gene FluG and the aflatoxin precursor acetyl-CoA. Transcriptomic analysis also demonstrated significant changes in secondary metabolism, energy metabolism, oxidative stress, and amino acid metabolism in the recovery group. Taken together, these findings provide new insights into the mechanisms underlying the response of A. flavus to CA vapor treatment and will guide the rational application of EOs.
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28
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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29
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Saber H, Chebloune Y, Moussaoui A. Molecular Characterization of Aspergillus flavus Strains Isolated from Animal Feeds. Pol J Microbiol 2022; 71:589-599. [PMID: 36537059 PMCID: PMC9944975 DOI: 10.33073/pjm-2022-048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 09/21/2022] [Indexed: 12/24/2022] Open
Abstract
Aflatoxin (AF)-producing fungi such as Aspergillus flavus commonly contaminate animal feeds, causing high economic losses. A. flavus is the most prevalent and produces AFB1, a potent mutagen, and carcinogen threatening human and animal health. Aspergillaceae is a large group of closely related fungi sharing number of morphological and genetic similarities that complicate the diagnosis of highly pathogenic strains. We used here morphological and molecular assays to characterize fungal isolates from animal feeds in Southwestern Algeria. These tools helped to identify 20 out of 30 Aspergillus strains, and 15 of them belonged to the Aspergillus section Flavi. Further analyses detected four out of 15 as belonging to Aspergillus flavus-parasiticus group. PCR targeting the AF genes' aflR-aflS(J) intergenic region amplified a single 674 bp amplicon in all four isolates. The amplicons were digested with a BglII endonuclease, and three specific fragments were observed for A. flavus but A. parasitucus lacked two typical fragments. Sequencing data of four amplicons confirmed the presence of the two BglII restriction sites yielding the three fragments, confirming that all four strains were A. flavus. In addition, this analysis illustrated the genetic variability within the A. flavus strains.
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Affiliation(s)
- Hadjer Saber
- Laboratory of Plant Resources Valorization and Food Safety in Semi-Arid Areas of Southwestern Algeria, Department of Biology, University of Bechar, Bechar, Algeria
| | - Yahia Chebloune
- USC 1450 INRAE/UGA Lentiviral Pathogenesis and Vaccination Laboratory, Department of Biology, University of Grenoble Alpes, Saint-Martin-d’Hères, France, Y. Chebloune, Lentiviral Pathogenesis and Vaccination Laboratory, PAVAL Lab., Department of Biology, University of Grenoble Alpes, Saint-Martin-d’Hères, France;
| | - Abdallah Moussaoui
- Laboratory of Plant Resources Valorization and Food Safety in Semi-Arid Areas of Southwestern Algeria, Department of Biology, University of Bechar, Bechar, Algeria
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30
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Wang J, Liang L, Wei S, Zhang S, Hu Y, Lv Y. Histone 2-Hydroxyisobutyryltransferase Encoded by Afngg1 Is Involved in Pathogenicity and Aflatoxin Biosynthesis in Aspergillus flavus. Toxins (Basel) 2022; 15:7. [PMID: 36668827 PMCID: PMC9861817 DOI: 10.3390/toxins15010007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 12/07/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Aflatoxin, a carcinogenic secondary metabolite produced by Aspergillus flavus, is a significant threat to human health and agricultural production. Histone 2-hydroxyisobutyrylation is a novel post-translational modification that regulates various biological processes, including secondary metabolism. In this study, we identified the novel histone 2-hydroxyisobutyryltransferase Afngg1 in A. flavus, and explored its role in cell growth, development and aflatoxin biosynthesis. Afngg1 gene deletion markedly decreased lysine 2-hydroxyisobutyrylation modification of histones H4K5 and H4K8 compared with the control strain. Additionally, Afngg1 deletion inhibited mycelial growth of A. flavus, and the number of conidia and hydrophobicity were significantly decreased. Notably, aflatoxin B1 biosynthesis and sclerotia production were completely inhibited in the ΔAfngg1 strain. Furthermore, the pathogenicity of the ΔAfngg1 strain infecting peanut and corn grains was also diminished, including reduced spore production and aflatoxin biosynthesis compared with A. flavus control and Afngg1 complementation strains. Transcriptome analysis showed that, compared with control strains, differentially expressed genes in ΔAfngg1 were mainly involved in chromatin remodelling, cell development, secondary metabolism and oxidative stress. These results suggest that Afngg1 is involved in histone 2-hydroxyisobutyrylation and chromatin modification, and thus affects cell development and aflatoxin biosynthesis in A. flavus. Our results lay a foundation for in-depth research on the 2-hydroxyisobutyrylation modification in A. flavus, and may provide a novel target for aflatoxin contamination prevention.
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Affiliation(s)
- Jing Wang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Liuke Liang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Shan Wei
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Shuaibing Zhang
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Yuansen Hu
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
| | - Yangyong Lv
- College of Biological Engineering, Henan University of Technology, Zhengzhou 450001, China
- Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou 450001, China
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Liang L, Yang H, Wei S, Zhang S, Chen L, Hu Y, Lv Y. Putative C 2H 2 Transcription Factor AflZKS3 Regulates Aflatoxin and Pathogenicity in Aspergillus flavus. Toxins (Basel) 2022; 14:toxins14120883. [PMID: 36548780 PMCID: PMC9786134 DOI: 10.3390/toxins14120883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/14/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Aflatoxin is a carcinogenic secondary metabolite that poses a serious threat to human and animal health. Some C2H2 transcription factors are associated with fungal growth and secondary metabolic regulation. In this study, we characterized the role of AflZKS3, a putative C2H2 transcription factor based on genome annotation, in the growth and aflatoxin biosynthesis of A. flavus and explored its possible mechanisms of action. Surprisingly, the protein was found to be located in the cytoplasm, and gene deletion in A. flavus resulted in defective growth and conidia formation, as well as increased sensitivity to the fluorescent brightener Calcofluor white, Congo red, NaCl, and sorbitol stress. Notably, the biosynthesis of aflatoxin B1 was completely inhibited in the ΔAflZKS3 deletion strain, and its ability to infect peanut and corn seeds was also reduced. RNA sequencing showed that differentially expressed genes in the ΔAflZKS3 strain compared with the control and complementation strains were mainly associated with growth, aflatoxin biosynthesis, and oxidative stress. Thus, AflZKS3 likely contributes to growth, cell development, and aflatoxin synthesis in A. flavus. These findings lay the foundation for a deeper understanding of the roles of C2H2 transcription factors in A. flavus and provide a potential biocontrol target for preventing aflatoxin contamination.
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Popescu RG, Rădulescu AL, Georgescu SE, Dinischiotu A. Aflatoxins in Feed: Types, Metabolism, Health Consequences in Swine and Mitigation Strategies. Toxins (Basel) 2022; 14. [PMID: 36548750 DOI: 10.3390/toxins14120853] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/21/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022] Open
Abstract
Feeding farm animals with aflatoxin-contaminated feed can cause various severe toxic effects, leading to increased susceptibility to infectious diseases and increased mortality, weight loss, poor performance and reduced reproductive capability. Following ingestion of contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in animals. Swine metabolism is not effective in detoxifying and excreting aflatoxins, meaning the risk of aflatoxicosis is increased. Thus, it is of great importance to elucidate the metabolism and all metabolic pathways associated with this mycotoxin. The damage induced by AFB1 in cells and tissues consists of inhibition of cell proliferation, carcinogenicity, immunosuppression, mutagenicity, oxidative stress, lipid peroxidation and DNA damage, leading to pathological lesions in the liver, spleen, lymph node, kidney, uterus, heart, and lungs of swine. At present, it is a challenging task and of serious concern to completely remove aflatoxins and their metabolites from feedstuff; thus, the aim of this study was a literature review on the deleterious effects of aflatoxins on swine metabolism, as well as alternatives that contribute to the detoxification or amelioration of aflatoxin-induced effects in farm animal feed.
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Sweany RR, Breunig M, Opoku J, Clay K, Spatafora JW, Drott MT, Baldwin TT, Fountain JC. Why Do Plant-Pathogenic Fungi Produce Mycotoxins? Potential Roles for Mycotoxins in the Plant Ecosystem. Phytopathology 2022; 112:2044-2051. [PMID: 35502928 DOI: 10.1094/phyto-02-22-0053-sym] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
For many plant-pathogenic or endophytic fungi, production of mycotoxins, which are toxic to humans, may present a fitness gain. However, associations between mycotoxin production and plant pathogenicity or virulence is inconsistent and difficult due to the complexity of these host-pathogen interactions and the influences of environmental and insect factors. Aflatoxin receives a lot of attention due to its potent toxicity and carcinogenicity but the connection between aflatoxin production and pathogenicity is complicated by the pathogenic ability and prevalence of nonaflatoxigenic isolates in crops. Other toxins directly aid fungi in planta, trichothecenes are important virulence factors, and ergot alkaloids limit herbivory and fungal consumption due to insect toxicity. We review a panel discussion at the American Phytopathological Society's Plant Health 2021 conference, which gathered diverse experts representing different research sectors, career stages, ethnicities, and genders to discuss the diverse roles of mycotoxins in the lifestyles of filamentous fungi of the families Clavicipitaceae, Trichocomaceae (Eurotiales), and Nectriaceae (Hypocreales).
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Affiliation(s)
- Rebecca R Sweany
- United States Department of Agriculture-Agricultural Research Service (USDA-ARS) Food and Feed Safety Research Unit, Southern Regional Research Center, New Orleans, LA 70124
| | - Mikaela Breunig
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 78824
| | - Joseph Opoku
- USDA-ARS Pest Management and Biological Control Research Unit, U.S. Arid-Land Agricultural Research Center, Tucson, AZ 85701
| | - Keith Clay
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA 70118
| | - Joseph W Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97333
| | - Milton T Drott
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI 53706
| | - Thomas T Baldwin
- Department of Plant Pathology, North Dakota State University, Fargo, ND 58108
| | - Jake C Fountain
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, MS State, MS 39762
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Wang L, Liu Q, Ge S, Liang W, Liao W, Li W, Jiao G, Wei X, Shao G, Xie L, Sheng Z, Hu S, Tang S, Hu P. Genomic footprints related with adaptation and fumonisins production in Fusarium proliferatum. Front Microbiol 2022; 13:1004454. [PMID: 36212817 PMCID: PMC9532532 DOI: 10.3389/fmicb.2022.1004454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/26/2022] [Indexed: 11/13/2022] Open
Abstract
Fusarium proliferatum is the principal etiological agent of rice spikelet rot disease (RSRD) in China, causing yield losses and fumonisins contamination in rice. The intraspecific variability and evolution pattern of the pathogen is poorly understood. Here, we performed whole-genome resequencing of 67 F. proliferatum strains collected from major rice-growing regions in China. Population structure indicated that eastern population of F. proliferatum located in Yangtze River with the high genetic diversity and recombinant mode that was predicted as the putative center of origin. Southern population and northeast population were likely been introduced into local populations through gene flow, and genetic differentiation between them might be shaped by rice-driven domestication. A total of 121 distinct genomic loci implicated 85 candidate genes were suggestively associated with variation of fumonisin B1 (FB1) production by genome-wide association study (GWAS). We subsequently tested the function of five candidate genes (gabap, chsD, palA, hxk1, and isw2) mapped in our association study by FB1 quantification of deletion strains, and mutants showed the impact on FB1 production as compared to the wide-type strain. Together, this is the first study to provide insights into the evolution and adaptation in natural populations of F. proliferatum on rice, as well as the complex genetic architecture for fumonisins biosynthesis.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Tsai J, Lai Y, Chen Y. Using Solid-Phase Microextraction Coupled with Reactive Carbon Fiber Ionization-Mass Spectrometry for the Detection of Aflatoxin B1 from Complex Samples. SEPARATIONS 2022; 9:199. [DOI: 10.3390/separations9080199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Aflatoxin B1 (AFB1) is a common mycotoxin present in agricultural and food products. Therefore, rapid screening methods must be developed for AFB1 detection with high sensitivity and good selectivity. In this study, we developed an analytical method based on the combination of solid-phase microextraction (SPME) with carbon fiber ionization (CFI)-mass spectrometry (MS) to detect the presence of trace AFB1 from complex samples. A pencil lead (type 2B, length: ~2.5 cm) with a sharp end (diameter: ~150 μm) was used as the SPME fiber and the ionization emitter in CFI-MS analysis. Owing to the graphite structure of the pencil lead, AFB1 can be trapped on the pencil lead through π–π interactions. After adsorbing AFB1, the pencil lead was directly introduced in a pipette tip (length: ~0.7 cm; tip inner diameter: ~0.6 mm), placed close (~1 mm) to the inlet of the mass spectrometer, and applied with a high voltage (−4.5 kV) for in situ AFB1 elution and CFI-MS analysis. A direct electric contact on the SPME-CFI setup was not required. Followed by the introduction of an elution solvent (10 μL) (acetonitrile/ethanol/deionized water, 2:2:1 (v/v/v)) to the pipette tip, electrospray ionization was generated from the elution solvent containing AFB1 for CFI-MS analysis. A reactive SPME-CFI-MS strategy was employed to further identify AFB1 and improve elution capacity using our approach. Butylamine was added to the elution solvent, which was then introduced to the pipette tip inserted with the SPME fiber. Butylamine-derivatized AFB1 was readily generated and appeared in the resultant SPME-CFI mass spectrum. The lowest detectable concentration against AFB1 using our approach was ~1.25 nM. Our method can distinguish AFB1 from AFG1 in a mixture and can be used for the detection of trace AFB1 in complex peanut extract samples.
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Sun H, Liu S, Zhang J, Zhang S, Mao J, Xu Y, Zhou J, Mao J. Safety evaluation and comparative genomics analysis of the industrial strain Aspergillus flavus SU-16 used for huangjiu brewing. Int J Food Microbiol 2022. [DOI: 10.1016/j.ijfoodmicro.2022.109859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 07/08/2022] [Accepted: 07/26/2022] [Indexed: 11/20/2022]
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Hu Y, Chai Q, Wang Y, Chen Y, Dong H, Shen J, Qi Y, Yu H, Wang F, Wen Q. Effects of Heat Stress and Exogenous Salicylic Acid on Secondary Metabolites Biosynthesis in Pleurotus ostreatus (Jacq.) P. Kumm. Life (Basel) 2022; 12:915. [PMID: 35743946 DOI: 10.3390/life12060915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 12/19/2022]
Abstract
Pleurotus ostreatus (Jacq.) P. Kumm has high medicinal value, but few studies exist on regulating secondary metabolite biosynthesis. Environmental factors play a substantial role in the accumulation of microbial secondary metabolites. In this study, the effects of heat stress (24 h) and salicylic acid (0.05 mmol/L) treatment on the secondary metabolism of P. ostreatus were analyzed by metabolome, transcriptome, and gene differential expression analysis. Metabolome and transcriptome analyses showed that salicylic acid significantly increased the accumulation of antibiotics and polyketones, while heat stress increased the accumulation of flavonoids, polyketones, terpenoids, and polysaccharides. The content and the biosynthetic genes expression of heparin were markedly increased by heat stress, and the former was increased by 4565.54-fold. This study provides a reference for future studies on secondary metabolite accumulation in edible fungi.
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Nigg M, de Oliveira TC, Sarmiento-Villamil JL, de la Bastide PY, Hintz WE, Sherif SM, Shukla M, Bernier L, Saxena PK. Comparative Analysis of Transcriptomes of Ophiostoma novo-ulmi ssp. americana Colonizing Resistant or Sensitive Genotypes of American Elm. J Fungi (Basel) 2022; 8:637. [PMID: 35736120 DOI: 10.3390/jof8060637] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/26/2022] [Accepted: 06/11/2022] [Indexed: 12/10/2022] Open
Abstract
The Ascomycete Ophiostoma novo-ulmi threatens elm populations worldwide. The molecular mechanisms underlying its pathogenicity and virulence are still largely uncharacterized. As part of a collaborative study of the O. novo-ulmi-elm interactome, we analyzed the O. novo-ulmi ssp. americana transcriptomes obtained by deep sequencing of messenger RNAs recovered from Ulmus americana saplings from one resistant (Valley Forge, VF) and one susceptible (S) elm genotypes at 0 and 96 h post-inoculation (hpi). Transcripts were identified for 6424 of the 8640 protein-coding genes annotated in the O. novo-ulmi nuclear genome. A total of 1439 genes expressed in planta had orthologs in the PHI-base curated database of genes involved in host-pathogen interactions, whereas 472 genes were considered differentially expressed (DEG) in S elms (370 genes) and VF elms (102 genes) at 96 hpi. Gene ontology (GO) terms for processes and activities associated with transport and transmembrane transport accounted for half (27/55) of GO terms that were significantly enriched in fungal genes upregulated in S elms, whereas the 22 GO terms enriched in genes overexpressed in VF elms included nine GO terms associated with metabolism, catabolism and transport of carbohydrates. Weighted gene co-expression network analysis identified three modules that were significantly associated with higher gene expression in S elms. The three modules accounted for 727 genes expressed in planta and included 103 DEGs upregulated in S elms. Knockdown- and knockout mutants were obtained for eight O. novo-ulmi genes. Although mutants remained virulent towards U. americana saplings, we identified a large repertoire of additional candidate O. novo-ulmi pathogenicity genes for functional validation by loss-of-function approaches.
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Wang S, Wang Y, Liu Y, Liu L, Li J, Yang K, Liu M, Zeng W, Qin L, Lin R, Nie X, Jiang L, Wang S. The Regulatory Role of the Aspergillus flavus Core Retromer Complex in Aflatoxin Metabolism. J Biol Chem 2022;:102120. [PMID: 35697069 DOI: 10.1016/j.jbc.2022.102120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 11/23/2022] Open
Abstract
Aflatoxins are a series of highly toxic and carcinogenic secondary metabolites that are synthesized by Aspergillus species. The degradation of aflatoxin enzymes is an important regulatory mechanism which modulates mycotoxin producing. The retromer complex is responsible for the retrograde transport of specific biomolecules and the vacuolar fusion in the intracellular transport. Late endosomal-associated GTPase (Rab7) has been shown to be a downstream effector protein of the retromer complex. A deficiency in the retromer complex or Rab7 results in several cellular trafficking problems in yeast and humans, like protein abnormal accumulation. However, whether retromer dysfunction is involved in aflatoxin synthesis remains unclear. Here, we report that the core retromer complex, which comprises three vacuolar protein sorting-associated proteins (AflVps26-AflVps29-AflVps35), is essential for the development of dormant and resistant fungal forms such as conidia (asexual reproductive spore) and sclerotia (hardened fungal mycelium), as well as aflatoxin production and pathogenicity, in Aspergillus flavus. In particular, we show the AflVps26-AflVps29-AflVps35 complex is negatively correlated with aflatoxin exportation. Structural simulation, site-specific mutagenesis, and coimmunoprecipitation experiments showed that interactions among AflVps26, AflVps29, and AflVps35 played crucial roles in the retromer complex executing its core functions. We further found an intrinsic connection between AflRab7 and the retromer involved in vesicle-vacuole fusion, which in turn affected the accumulation of aflatoxin synthesis-associated enzymes, suggesting that they work together to regulate the production of toxins. Overall, these results provide mechanistic insights that contribute to our understanding of the regulatory role of the core retromer complex in aflatoxin metabolism.
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Li Q, Zhao Y, Zuo X, Guo F, Li Y, Xie Y. Paeonol inhibits Aspergillus flavus via disrupting ergosterol biosynthesis, redox metabolism, and aflatoxin biosynthesis on rice. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Lv Y, Wang J, Yang H, Li N, Farzaneh M, Wei S, Zhai H, Zhang S, Hu Y. Lysine 2-hydroxyisobutyrylation orchestrates cell development and aflatoxin biosynthesis in Aspergillus flavus. Environ Microbiol 2022; 24:4356-4368. [PMID: 35621059 DOI: 10.1111/1462-2920.16077] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 05/17/2022] [Indexed: 11/30/2022]
Abstract
Lysine 2-hydroxyisobutyrylation (Khib ) is a recently identified post-translational modifications (PTM) that regulates numerous cellular metabolic processes. In pathogenic microorganism, although glycolysis and fungal virulence are regulated by Khib , its potential roles in fungi remains to be elusive. Our preliminary results showed that levels of Khib fluctuate over time in Aspergillus flavus, which frequently contaminates crops and produces carcinogenic aflatoxins. However, the perception of Khib function in A. flavus is limited, especially in mycotoxin-producing strains. Here, we performed a comprehensive analysis of Khib in A. flavus, and 7156 Khib sites were identified in 1473 proteins. Notably, we demonstrated that Khib of AflM, a key enzyme in aflatoxin biosynthesis, affected conidia production and sclerotia formation. Furthermore, aflM deletion impaired aflatoxin biosynthesis, and more importantly, strains in which Khib was mimicked by K to T mutation at K49, K179 and K180 sites showed reduced aflatoxin production compared with wild type and ΔaflM complementation strains. These results indicate that Khib at these sites of AflM negatively regulates aflatoxin biosynthesis in A. flavus. In summary, our study revealed the potential roles of Khib in A. flavus, and particularly shed light on a new way to regulate aflatoxin production via Khib . This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Yangyong Lv
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Jing Wang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Haojie Yang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Na Li
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Mohsen Farzaneh
- Department of Agriculture, Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411, Tehran, Iran
| | - Shan Wei
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Huanchen Zhai
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Shuaibing Zhang
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
| | - Yuansen Hu
- College of Biological Engineering, Henan University of Technology, Zhengzhou, 450001, People's Republic of China.,Henan Provincial Key Laboratory of Biological Processing and Nutritional Function of Wheat, Zhengzhou, 450001, People's Republic of China
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Yaseen S, Hanano A. Quantitative PCR (qPCR) Reveals that the Aflatoxin-Free Pistachio Samples Can Be Potentially Contaminated with Fungal Materials. FOOD ANAL METHOD 2022. [DOI: 10.1007/s12161-022-02327-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Buitimea-Cantúa GV, Leija Gutiérrez HM, Buitimea-Cantúa NE, Del Refugio Rocha-Pizaña M, García-Triana A, Hernández-Morales A, Magaña-Barajas E, Molina-Torres J. The aflatoxin inhibitors capsaicin and piperine from Capsicum chinense and Piper nigrum fruits modulate the antioxidant system in Aspergillus parasiticus. J Environ Sci Health B 2022; 57:358-368. [PMID: 35392762 DOI: 10.1080/03601234.2022.2060029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Several aflatoxin inhibitors can modulate the antioxidant system in fungi. In this work, the effect of the ethanolic extract of Capsicum chinense and Piper nigrum fruits, capsaicin, and piperine on the expression of the aflE, aflG, aflH, aflI, aflK, aflL, aflO, aflP, and aflQ genes involved in the aflatoxin biosynthetic pathway in Aspergillus parasiticus were studied by qRT-PCR analysis. As well as, the effect on the expression of fungal antioxidant genes (sod1, catA, and cat2) and enzymatic activity of catalase (CAT) and superoxide dismutase (SOD). Results reveal that the highest (p < 0.05) radial growth inhibition (68 and 86%) and aflatoxins production inhibition (73 and 80%) was observed with capsaicin and piperine respectively, at 300 µg/mL, instead of the ethanolic extract at the same concentration. The qRT-PCR analysis showed that compounds and extracts at 300 µg/mL induced a down-regulation of aflatoxin genes and an up-regulation on the fungal antioxidant genes. CAT activity increased by 23.15, 36.65, 51.40, and 65.50%, in the presence of C. chinense and P. nigrum extract, capsaicin, and piperine exposure, respectively. While SOD activity was not significantly impacted (p > 0.05). In conclusion, the capsaicin and piperine, two antifungal and anti-aflatoxigenic compounds produce an up-regulation of antioxidant defense genes accompanied by an enhancement of catalase enzymatic activity in A. parasiticus.
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Affiliation(s)
- Génesis V Buitimea-Cantúa
- Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Centro de Biotecnología-FEMSA, Monterrey, NL, México
- CINVESTAV, Departamento de Biotecnología y Bioquímica, Irapuato, Guanajuato, México
| | - Héctor Manuel Leija Gutiérrez
- Universidad Autónoma de Nuevo León, Centro de Investigación Facultad de Ciencias Físico Matemáticas, San Nicolás de los Garza, Nuevo León, México
| | - Nydia E Buitimea-Cantúa
- Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Centro de Biotecnología-FEMSA, Monterrey, NL, México
| | | | | | - Alejandro Hernández-Morales
- Facultad de Estudios Profesionales Zona Huasteca, Universidad Autónoma de San Luis Potosí, Ciudad Valles, San Luis Potosí, México
| | - Elisa Magaña-Barajas
- Programa de Ingeniería en Tecnologías de Alimentos, Universidad Estatal de Sonora, Perimetral y Ley, Hermosillo, SO, México
| | - Jorge Molina-Torres
- CINVESTAV, Departamento de Biotecnología y Bioquímica, Irapuato, Guanajuato, México
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Zhao Q, Pei H, Zhou X, Zhao K, Yu M, Han G, Fan J, Tao F. Systematic Characterization of bZIP Transcription Factors Required for Development and Aflatoxin Generation by High-Throughput Gene Knockout in Aspergillus flavus. J Fungi (Basel) 2022; 8:356. [PMID: 35448587 PMCID: PMC9031554 DOI: 10.3390/jof8040356] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022] Open
Abstract
The basic leucine zipper (bZIP) is an important transcription factor required for fungal development, nutrient utilization, biosynthesis of secondary metabolites, and defense against various stresses. Aspergillus flavus is a major producer of aflatoxin and an opportunistic fungus on a wide range of hosts. However, little is known about the role of most bZIP genes in A. flavus. In this study, we developed a high-throughput gene knockout method based on an Agrobacterium-mediated transformation system. Gene knockout construction by yeast recombinational cloning and screening of the null mutants by double fluorescence provides an efficient way to construct gene-deleted mutants for this multinucleate fungus. We deleted 15 bZIP genes in A. flavus. Twelve of these genes were identified and characterized in this strain for the first time. The phenotypic analysis of these mutants showed that the 15 bZIP genes play a diverse role in mycelial growth (eight genes), conidiation (13 genes), aflatoxin biosynthesis (10 genes), oxidative stress response (11 genes), cell wall stress (five genes), osmotic stress (three genes), acid and alkali stress (four genes), and virulence to kernels (nine genes). Impressively, all 15 genes were involved in the development of sclerotia, and the respective deletion mutants of five of them did not produce sclerotia. Moreover, MetR was involved in this biological process. In addition, HapX and MetR play important roles in the adaptation to excessive iron and sulfur metabolism, respectively. These studies provide comprehensive insights into the role of bZIP transcription factors in this aflatoxigenic fungus of global significance.
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Razzaghi-Abyaneh M, Chen ZY, Shams-Ghahfarokhi M, Rai M. Editorial: Research Efforts, Challenges, and Opportunities in Mitigating Aflatoxins in Food and Agricultural Crops and Its Global Health Impacts. Front Microbiol 2022; 13:881858. [PMID: 35391739 PMCID: PMC8981455 DOI: 10.3389/fmicb.2022.881858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Mehdi Razzaghi-Abyaneh
- Department of Mycology, Pasteur Institute of Iran, Tehran, Iran
- *Correspondence: Mehdi Razzaghi-Abyaneh
| | - Zhi-Yuan Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, Baton Rouge, LA, United States
| | | | - Mahendra Rai
- Department of Biotechnology, Sant Gadge Baba Amravati University, Amravati, India
- Department of Microbiology, Nicolaus Copernicus University, Torun, Poland
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Ajmal M, Alshannaq AF, Moon H, Choi D, Akram A, Nayyar BG, Gibbons JG, Yu JH. Characterization of 260 Isolates of Aspergillus Section Flavi Obtained from Sesame Seeds in Punjab, Pakistan. Toxins (Basel) 2022; 14:toxins14020117. [PMID: 35202144 PMCID: PMC8876583 DOI: 10.3390/toxins14020117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/31/2022] [Accepted: 02/02/2022] [Indexed: 11/16/2022] Open
Abstract
Sesame Sesamum indicum L. is a major oil-based seed crop that has been widely cultivated and consumed in Pakistan. Unfortunately, sesame is highly prone to Aspergillus fungal growth in the field, and under inappropriate storage conditions can become contaminated with aflatoxins, the most potent carcinogen found in nature. Here, we have isolated a high number of Aspergillus isolates from sesame seeds in fresh and stored conditions obtained from rainfed and irrigated zones of Punjab, Pakistan, and characterized them for aflatoxigenic potentials. Using morphological identification techniques, 260 isolates were grouped as potential Aspergillus section Flavi, with 126 and 134 originating from the rainfed and irrigated zones, respectively. Out of 260 in total, 188 isolates were confirmed to produce aflatoxins. There were no significant differences in potential aflatoxigenic isolates with respect to the rainfed and irrigated zones. However, the number of potential aflatoxigenic isolates was significantly higher (p < 0.05) in stored samples than that of those from fresh sesame seeds in the rainfed and irrigated zone. Whole genome sequencing and comparative analyses of 12 select isolates have revealed that one of the A. flavus isolates, which produced very low aflatoxins (AFP10), has an elevated missense variant rate, numerous high impact mutations, and a 600 base pair deletion in the norB gene. In summary, our study provides insights into aflatoxigenic potential and the associated genetic diversity of indigenous Aspergillus section Flavi isolates and potential management strategies for reducing aflatoxin contamination levels in a major crop consumed in Punjab, Pakistan.
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Affiliation(s)
- Maryam Ajmal
- Department of Botany, Faculty of Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46300, Pakistan; (M.A.); (A.A.)
| | - Ahmad F. Alshannaq
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA; (A.F.A.); (H.M.); (D.C.)
| | - Heungyun Moon
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA; (A.F.A.); (H.M.); (D.C.)
| | - Dasol Choi
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA; (A.F.A.); (H.M.); (D.C.)
| | - Abida Akram
- Department of Botany, Faculty of Sciences, Pir Mehr Ali Shah Arid Agriculture University, Rawalpindi 46300, Pakistan; (M.A.); (A.A.)
| | - Brian Gagosh Nayyar
- Department of Botany, Faculty of Sciences, University of Sialkot, Sialkot 51310, Pakistan;
| | - John G. Gibbons
- Department of Food Science, College of Natural Sciences, University of Massachusetts, Amherst, MA 01003, USA;
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin-Madison, 1550 Linden Drive, Madison, WI 53706, USA; (A.F.A.); (H.M.); (D.C.)
- Department of Systems Biotechnology, Konkuk Institute of Science and Technology, Konkuk University, Seoul 05029, Korea
- Correspondence:
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Reis T, Tralamazza S, Coelho E, Zorzete P, Corrêa B. Early expression of the aflatoxin gene cluster in Aspergillus nomiae isolated from Brazil nut. Toxicon 2022; 209:36-42. [DOI: 10.1016/j.toxicon.2022.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 12/30/2021] [Accepted: 01/21/2022] [Indexed: 10/19/2022]
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Dai L, Zheng J, Ye J, Chen H. Phylogeny of Leptographium qinlingensis cytochrome P450 genes and transcription levels of six CYPs in response to different nutrition media or terpenoids. Arch Microbiol 2022; 204. [DOI: 10.1007/s00203-021-02616-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 11/29/2021] [Accepted: 11/30/2021] [Indexed: 12/16/2022]
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Chakraborty P. Gene cluster from plant to microbes: Their role in genome architecture, organism's development, specialized metabolism and drug discovery. Biochimie 2021; 193:1-15. [PMID: 34890733 DOI: 10.1016/j.biochi.2021.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 12/01/2021] [Accepted: 12/04/2021] [Indexed: 02/07/2023]
Abstract
Plants and microbes fulfil our daily requirements through different high-value chemicals, e.g., nutraceuticals, pharmaceuticals, cosmetics, and through varieties of fruits, crops, vegetables, and many more. Utmost care would therefore be taken for growth, development and sustainability of these important crops and medicinal plants and microbes. Homeobox genes and HOX clusters and their recently characterized expanded family members, including newly discovered homeobox, WOX gene from medicinal herb, Panax ginseng, significantly contributes in the growth and development of these organisms. On the other hand, secondary metabolites produced through secondary metabolism of plants and microbes are used as organisms defense as well as drugs/drug-like molecules for humans. Both the developmental HOX cluster and the biosynthetic gene-cluster (BGC) for secondary metabolites are organised in organisms genome. Genome mining and genomewide analysis of these clusters will definitely identify and characterize many more important molecules from unexplored plants and microbes and underexplored human microbiota and the evolution studies of these clusters will indicate their source of origin. Although genomics revolution now continues at a pace, till date only few hundred plant genome sequences are available. However, next-generation sequencing (NGS) technology now in market and may be applied even for plants with recalcitrant genomes, eventually may discover genomic potential towards production of secondary metabolites of diverse plants and micro-organisms present in the environment and microbiota. Additionally, the development of tools for genome mining e.g., antiSMASH, plantiSMASH, and more and more computational approaches that predicts hundreds of secondary metabolite BGCs will be discussed.
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Affiliation(s)
- Prasanta Chakraborty
- Kalpana Chawla Center for Space and Nanoscience, Kolkata, Indian Institute of Chemical Biology (retd.), Kolkata, 700032, India.
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