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Sherif M, Kirsch N, Splivallo R, Pfohl K, Karlovsky P. The Role of Mycotoxins in Interactions between Fusarium graminearum and F. verticillioides Growing in Saprophytic Cultures and Co-Infecting Maize Plants. Toxins (Basel) 2023; 15:575. [PMID: 37756001 PMCID: PMC10538043 DOI: 10.3390/toxins15090575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/10/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
Fusarium graminearum (FG) and Fusarium verticillioides (FV) co-occur in infected plants and plant residues. In maize ears, the growth of FV is stimulated while FG is suppressed. To elucidate the role of mycotoxins in these effects, we used FG mutants with disrupted synthesis of nivalenol (NIV) and deoxynivalenol (DON) and a FV mutant with disrupted synthesis of fumonisins to monitor fungal growth in mixed cultures in vitro and in co-infected plants by real-time PCR. In autoclaved grains as well as in maize ears, the growth of FV was stimulated by FG regardless of the production of DON or NIV by the latter, whereas the growth of FG was suppressed. In autoclaved grains, fumonisin-producing FV suppressed FG more strongly than a fumonisin-nonproducing strain, indicating that fumonisins act as interference competition agents. In co-infected maize ears, FG suppression was independent of fumonisin production by FV, likely due to heterogeneous infection and a lower level of fumonisins in planta. We conclude that (i) fumonisins are agents of interference competition of FV, and (ii) trichothecenes play no role in the interaction between FG and FV. We hypothesize the following: (i) In vitro, FG stimulates the FV growth by secreting hydrolases that mobilize nutrients. In planta, suppression of plant defense by FG may additionally play a role. (ii) The biological function of fumonisin production in planta is to protect kernels shed on the ground by accumulating protective metabolites before competitors become established. Therefore, to decipher the biological function of mycotoxins, the entire life history of mycotoxin producers must be considered.
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Affiliation(s)
- Mohammed Sherif
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
- Phytopathology Unit, Plant Protection Department, Desert Research Center, Cairo 11753, Egypt
| | - Nadine Kirsch
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for National and International Plant Health, Julius Kühn-Institut, 38104 Braunschweig, Germany
| | - Richard Splivallo
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
- Nectariss Grasse SAS, 06130 Grasse, France
| | - Katharina Pfohl
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for National and International Plant Health, Julius Kühn-Institut, 38104 Braunschweig, Germany
| | - Petr Karlovsky
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
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Chen X, Abdallah MF, Landschoot S, Audenaert K, De Saeger S, Chen X, Rajkovic A. Aspergillus flavus and Fusarium verticillioides and Their Main Mycotoxins: Global Distribution and Scenarios of Interactions in Maize. Toxins (Basel) 2023; 15:577. [PMID: 37756003 PMCID: PMC10534665 DOI: 10.3390/toxins15090577] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/25/2023] [Accepted: 09/04/2023] [Indexed: 09/28/2023] Open
Abstract
Maize is frequently contaminated with multiple mycotoxins, especially those produced by Aspergillus flavus and Fusarium verticillioides. As mycotoxin contamination is a critical factor that destabilizes global food safety, the current review provides an updated overview of the (co-)occurrence of A. flavus and F. verticillioides and (co-)contamination of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) in maize. Furthermore, it summarizes their interactions in maize. The gathered data predict the (co-)occurrence and virulence of A. flavus and F. verticillioides would increase worldwide, especially in European cold climate countries. Studies on the interaction of both fungi regarding their growth mainly showed antagonistic interactions in vitro or in planta conditions. However, the (co-)contamination of AFB1 and FB1 has risen worldwide in the last decade. Primarily, this co-contamination increased by 32% in Europe (2010-2020 vs. 1992-2009). This implies that fungi and mycotoxins would severely threaten European-grown maize.
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Affiliation(s)
- Xiangrong Chen
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (M.F.A.); (A.R.)
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (S.L.); (K.A.)
| | - Mohamed F. Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (M.F.A.); (A.R.)
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Assiut 71515, Egypt
| | - Sofie Landschoot
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (S.L.); (K.A.)
| | - Kris Audenaert
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (S.L.); (K.A.)
| | - Sarah De Saeger
- Centre of Excellence in Mycotoxicology and Public Health, Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, 9000 Ghent, Belgium;
- Department of Biotechnology and Food Technology, Faculty of Science, University of Johannesburg, Doornfontein Campus, P.O. Box 17011, Gauteng 2028, South Africa
| | - Xiangfeng Chen
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Science), Jinan 250014, China;
| | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (M.F.A.); (A.R.)
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Chen X, Abdallah MF, Grootaert C, Van Nieuwerburgh F, Rajkovic A. New insights into the combined toxicity of aflatoxin B1 and fumonisin B1 in HepG2 cells using Seahorse respirometry analysis and RNA transcriptome sequencing. ENVIRONMENT INTERNATIONAL 2023; 175:107945. [PMID: 37126917 DOI: 10.1016/j.envint.2023.107945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 04/08/2023] [Accepted: 04/19/2023] [Indexed: 05/03/2023]
Abstract
Aflatoxin B1 (AFB1) and fumonisin B1 (FB1) are widely (co-)detected in food and known for their hepatotoxicity in humans. Still, their combined toxicity needs to be investigated, especially the impact on mitochondria. In our previous work, we examined the effect of short-term exposure to different doses of AFB1, FB1, and their binary mixture (MIX) on the bioenergetic status of HepG2 cells, a well-recognized in vitro model system for studying liver cell function. In the current work, we further investigated the (combined) effect of AFB1 and FB1 on the mitochondrial and glycolytic activity of HepG2 cells using Seahorse respirometry analysis and RNA transcriptome sequencing. The results showed that the co-exposure, especially at high doses, is more toxic due to a more inhibition of all parameters of mitochondrial respiration. However, FB1 contributes more to the MIX effects than AFB1. RNA transcriptome sequencing showed that the p53 signaling pathway, a major orchestrator of mitochondrial apoptosis, was differentially expressed. Moreover, the co-exposure significantly downregulated the genes encoding for Complexes I, II, III, and IV, representing the onset of the suppressed mitochondrial respiration in HepG2 cells.
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Affiliation(s)
- Xiangrong Chen
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
| | - Mohamed F Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium; Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Charlotte Grootaert
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Filip Van Nieuwerburgh
- Laboratory of Pharmaceutical Biotechnology, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium
| | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
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Chen X, Abdallah MF, Grootaert C, Rajkovic A. Bioenergetic Status of the Intestinal and Hepatic Cells after Short Term Exposure to Fumonisin B1 and Aflatoxin B1. Int J Mol Sci 2022; 23:ijms23136945. [PMID: 35805950 PMCID: PMC9267062 DOI: 10.3390/ijms23136945] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/20/2022] [Accepted: 06/21/2022] [Indexed: 12/12/2022] Open
Abstract
Fumonisin B1 (FB1) and aflatoxin B1 (AFB1) are frequent contaminants of staple foods such as maize. Oral exposure to these toxins poses health hazards by disrupting cellular signaling. However, little is known regarding the multifaced mitochondrial dysfunction-linked toxicity of FB1 and AFB1. Here, we show that after exposure to FB1 and AFB1, mitochondrial respiration significantly decreased by measuring the oxygen consumption rate (OCR), mitochondrial membrane potential (MMP) and reactive oxygen species (ROS). The current work shows that the integrity of mitochondria (MMP and ROS), that is the central component of cell apoptosis, is disrupted by FB1 and AFB1 in undifferentiated Caco-2 and HepG2 cells as in vitro models for human intestine and liver, respectively. It hypothesizes that FB1 and AFB1 could disrupt the mitochondrial electron transport chain (ETC) to induce mitochondrial dysfunction and break the balance of transferring H+ between the mitochondrial inner membrane and mitochondrial matrix, however, the proton leak is not increasing and, as a result, ATP synthesis is blocked. At the sub-toxic exposure of 1.0 µg/mL for 24 h, i.e., a viability of 95% in Caco-2 and HepG2 cells, the mitochondrial respiration was, however, stimulated. This suggests that the treated cells could reserve energy for mitochondrial respiration with the exposure of FB1 and AFB1, which could be a survival advantage.
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Affiliation(s)
- Xiangrong Chen
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (X.C.); (M.F.A.); (C.G.)
| | - Mohamed F. Abdallah
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (X.C.); (M.F.A.); (C.G.)
- Department of Forensic Medicine and Toxicology, Faculty of Veterinary Medicine, Assiut University, Assiut 71515, Egypt
| | - Charlotte Grootaert
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (X.C.); (M.F.A.); (C.G.)
| | - Andreja Rajkovic
- Department of Food Technology, Safety and Health, Faculty of Bioscience Engineering, Ghent University, 9000 Ghent, Belgium; (X.C.); (M.F.A.); (C.G.)
- Correspondence: ; Tel.: +32-09-264-99-04
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Fusarium verticillioides and Aspergillus flavus Co-Occurrence Influences Plant and Fungal Transcriptional Profiles in Maize Kernels and In Vitro. Toxins (Basel) 2021; 13:toxins13100680. [PMID: 34678972 PMCID: PMC8537323 DOI: 10.3390/toxins13100680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/09/2021] [Accepted: 09/17/2021] [Indexed: 12/26/2022] Open
Abstract
Climate change will increase the co-occurrence of Fusarium verticillioides and Aspergillus flavus, along with their mycotoxins, in European maize. In this study, the expression profiles of two pathogenesis-related (PR) genes and four mycotoxin biosynthetic genes, FUM1 and FUM13, fumonisin pathway, and aflR and aflD, aflatoxin pathway, as well as mycotoxin production, were examined in kernels and in artificial medium after a single inoculation with F. verticillioides or A. flavus or with the two fungi in combination. Different temperature regimes (20, 25 and 30 °C) over a time-course of 21 days were also considered. In maize kernels, PR genes showed the strongest induction at 25 °C in the earlier days post inoculation (dpi)with both fungi inoculated singularly. A similar behaviour was maintained with fungi co-occurrence, but with enhanced defence response at 9 dpi under 20 °C. Regarding FUM genes, in the kernels inoculated with F. verticillioides the maximal transcript levels occurred at 6 dpi at 25 °C. At this temperature regime, expression values decreased with the co-occurrence of A. flavus, where the highest gene induction was detected at 20 °C. Similar results were observed in fungi grown in vitro, whilst A. flavus presence determined lower levels of expression along the entire time-course. As concerns afl genes, considering both A. flavus alone and in combination, the most elevated transcript accumulation occurred at 30 °C during all time-course both in infected kernels and in fungi grown in vitro. Regarding mycotoxin production, no significant differences were found among temperatures for kernel contamination, whereas in vitro the highest production was registered at 25 °C for aflatoxin B1 and at 20 °C for fumonisins in the case of single inoculation. In fungal co-occurrence, both mycotoxins resulted reduced at all the temperatures considered compared to the amount produced with single inoculation.
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