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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] [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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2
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Atehnkeng J, Ojiambo PS, Ortega-Beltran A, Augusto J, Cotty PJ, Bandyopadhyay R. Impact of frequency of application on the long-term efficacy of the biocontrol product Aflasafe in reducing aflatoxin contamination in maize. Front Microbiol 2022; 13:1049013. [PMID: 36504767 PMCID: PMC9732863 DOI: 10.3389/fmicb.2022.1049013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 10/31/2022] [Indexed: 11/25/2022] Open
Abstract
Aflatoxins, produced by several Aspergillus section Flavi species in various crops, are a significant public health risk and a barrier to trade and development. In sub-Saharan Africa, maize and groundnut are particularly vulnerable to aflatoxin contamination. Aflasafe, a registered aflatoxin biocontrol product, utilizes atoxigenic A. flavus genotypes native to Nigeria to displace aflatoxin producers and mitigate aflatoxin contamination. Aflasafe was evaluated in farmers' fields for 3 years, under various regimens, to quantify carry-over of the biocontrol active ingredient genotypes. Nine maize fields were each treated either continuously for 3 years, the first two successive years, in year 1 and year 3, or once during the first year. For each treated field, a nearby untreated field was monitored. Aflatoxins were quantified in grain at harvest and after simulated poor storage. Biocontrol efficacy and frequencies of the active ingredient genotypes decreased in the absence of annual treatment. Maize treated consecutively for 2 or 3 years had significantly (p < 0.05) less aflatoxin (92% less) in grain at harvest than untreated maize. Maize grain from treated fields subjected to simulated poor storage had significantly less (p < 0.05) aflatoxin than grain from untreated fields, regardless of application regimen. Active ingredients occurred at higher frequencies in soil and grain from treated fields than from untreated fields. The incidence of active ingredients recovered in soil was significantly correlated (r = 0.898; p < 0.001) with the incidence of active ingredients in grain, which in turn was also significantly correlated (r = -0.621, p = 0.02) with aflatoxin concentration. Although there were carry-over effects, caution should be taken when drawing recommendations about discontinuing biocontrol use. Cost-benefit analyses of single season and carry-over influences are needed to optimize use by communities of smallholder farmers in sub-Saharan Africa.
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Affiliation(s)
- Joseph Atehnkeng
- Pathology and Mycotoxin, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Peter S. Ojiambo
- Pathology and Mycotoxin, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria,Center for Integrated Fungal Research, Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC, United States
| | - Alejandro Ortega-Beltran
- Pathology and Mycotoxin, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Joao Augusto
- Pathology and Mycotoxin, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - Peter J. Cotty
- College of Food Science and Engineering, Ocean University of China, Qingdao, China,Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
| | - Ranajit Bandyopadhyay
- Pathology and Mycotoxin, International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria,*Correspondence: Ranajit Bandyopadhyay,
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3
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Senghor AL, Ortega-Beltran A, Atehnkeng J, Jarju P, Cotty PJ, Bandyopadhyay R. Aflasafe SN01 is the First Biocontrol Product Approved for Aflatoxin Mitigation in Two Nations, Senegal and The Gambia. PLANT DISEASE 2021; 105:1461-1473. [PMID: 33332161 DOI: 10.1094/pdis-09-20-1899-re] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Aflatoxin contamination is caused by Aspergillus flavus and closely related fungi. In The Gambia, aflatoxin contamination of groundnut and maize, two staple and economically important crops, is common. Groundnut and maize consumers are chronically exposed to aflatoxins, sometimes at alarming levels, and this has severe consequences on their health and productivity. Aflatoxin contamination also impedes commercialization in local and international premium markets. In neighboring Senegal, an aflatoxin biocontrol product containing four atoxigenic isolates of A. flavus, Aflasafe SN01, has been registered and is approved for commercial use in groundnut and maize. We detected that the four genotypes composing Aflasafe SN01 are also native to The Gambia. The biocontrol product was tested during two years in 129 maize and groundnut fields and compared with corresponding untreated fields cropped by smallholder farmers in The Gambia. Treated crops contained up to 100% less aflatoxins than untreated crops. A large portion of the crops could have been commercialized in premium markets due to the low aflatoxin content (in many cases no detectable aflatoxins), both at harvest and after storage. Substantial aflatoxin reductions were also achieved when commercially produced groundnut received treatment. Here we report for the first time the use and effectiveness of an aflatoxin biocontrol product registered for use in two nations. With the current scale-out and -up efforts of Aflasafe SN01, a large number of farmers, consumers, and traders in The Gambia and Senegal will obtain health, income, and trade benefits.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- A L Senghor
- La Direction de Protection Végétaux, BP20054 Dakar, Senegal
| | - A Ortega-Beltran
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - J Atehnkeng
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
| | - P Jarju
- National Food Security, Processing and Marketing Corporation, Denton Bridge, Banjul, The Gambia
| | - P J Cotty
- United States Department of Agriculture, Agricultural Research Service, Tucson, AZ 85719, U.S.A
- College of Food Science and Engineering, Ocean University of China, Qingdao, 266003, China
| | - R Bandyopadhyay
- International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria
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Xie H, Jallow A, Yue X, Wang X, Fu J, Mwakinyali SE, Zhang Q, Li P. Aspergillus flavus's Response to Antagonism Bacterial Stress Sheds Light on a Regulation and Metabolic Trade-Off Mechanism for Adversity Survival. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:4840-4848. [PMID: 33856211 DOI: 10.1021/acs.jafc.0c07665] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Biocontrol to combat the menace of Aspergillus flavus has gained considerable attention. However, the molecular mechanisms of A. flavus 's response to antagonism biotic stress are poorly deciphered. Here, we discovered that A. flavus switches an adaptive metabolic reprogramming to ensure its adversity survival by multiomics analyses (including four omics platform). Antifungal "weapons" lipopeptides and antibacterial metabolites of imizoquin were identified. The central metabolism fluxes were significantly depleted but the expressions of most corresponding genes were considerably increased in A. flavus. Secondary metabolism that does not contribute to stress was markedly suppressed. In contrast, A. flavus antibacterial "weapon arsenal" was activated to occupy an ecological niche. Our results revealed that interlinked mitochondrial central metabolism and secondary metabolism are central to A. flavus antagonism biotic stress response. This discovery contributes to the targeted design of biocontrol agents and smart regularization of rhizosphere microbiome homeostasis to realize long-term fungi pathogen control and mitigation mycotoxin contamination.
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Affiliation(s)
- Huali Xie
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Abdoulie Jallow
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Xiaofeng Yue
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Xiuping Wang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Quality Inspection and Test Center for Oilseeds Products, Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Jiayun Fu
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Quality Inspection and Test Center for Oilseeds Products, Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Silvano E Mwakinyali
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Qi Zhang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Quality Inspection and Test Center for Oilseeds Products, Ministry of Agriculture, Wuhan 430061, People's Republic of China
| | - Peiwu Li
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430061, People's Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Key Laboratory of Detection for Aflatoxins, Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Laboratory of Risk Assessment for Oilseeds Products (Wuhan), Ministry of Agriculture, Wuhan 430061, People's Republic of China
- Quality Inspection and Test Center for Oilseeds Products, Ministry of Agriculture, Wuhan 430061, People's Republic of China
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Labib MM, Amin MK, Alzohairy AM, Elashtokhy MMA, Samir O, Saleh I, Arif IA, Osman GH, Hassanein SE. In silico Targeting, inhibition and analysis of polyketide synthase enzyme in Aspergillus ssp. Saudi J Biol Sci 2020; 27:3187-3198. [PMID: 33304124 PMCID: PMC7715038 DOI: 10.1016/j.sjbs.2020.10.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 09/28/2020] [Accepted: 10/07/2020] [Indexed: 12/30/2022] Open
Abstract
Aflatoxins are toxic and carcinogenic components produced by some Aspergillus species such as Aspergillus flavus. Polyketide synthases enzyme (PKS) plays a central role in aflatoxin s biosynthesis of in Aspergillus flavus, especially the product template (PT) domain, which controls the aldol cyclization of the polyketide forerunner during the biosynthesis of the aflatoxin pathway process. Here, we apply the in silico approaches to validate 623 natural components obtained from the South African Natural Compound Database (SANCDB), to distinguish the PT domain s prospected inhibitors. From the 623 compounds, docking results showed that there are 330 different compounds with energy binding lower than the natural substrate (palmitic acid or PLM) of the Product Templet domain (PT). Three factors were selected to determine the best 10 inhibiting components; 1) energy binding, 2) the strengthen chemical interactions, 3) the drug-likeness. The top ten inhibiting components are kraussianone 6, kraussianone 1, neodiospyrin, clionamine D, bromotopsentin, isodiospyrin, spongotine A, kraussianone 3, 14β-Hydroxybufa-3,5,20,22-tetraenolide and kraussianone 7. The chemical interactions between 3HRQ domain and the natural substrate in the active site amino acids are highly similar to the 3HRQ with the top ten components, but the main differences are in the binding energy which is the best in the top ten ligands. Those ten components give successful inhibition with PT domain which will lead to the formula to be used for inhibition and control aflatoxin contamination of agriculture crop yields and lessen the degree of harming and sicknesses that are coming about because of acquiring measures of aflatoxin.
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Affiliation(s)
- Mai M Labib
- Agriculture Genetic Engineering Research Institute (AGERI), Egypt
| | - M K Amin
- Faculty of Agriculture, Zagazig University, Department of Genetics
| | - A M Alzohairy
- Faculty of Agriculture, Zagazig University, Department of Genetics
| | - M M A Elashtokhy
- Faculty of Agriculture, Zagazig University, Department of Genetics
| | - O Samir
- Misr University for Science and Technology (MUST), October 6, Al Jizah, Egypt
| | - I Saleh
- Botany and Microbiology Department, Faculty of Sciences, King Saud University, Saudi Arabia
| | - I A Arif
- Botany and Microbiology Department, Faculty of Sciences, King Saud University, Saudi Arabia
| | - G H Osman
- Department of Biology, Faculty of Applied Sciences, Umm Al-Qura University, Makkah, Saudi Arabia.,Research Laboratories Center, Faculty of Applied Science, Umm Al-Qura University, Mecca, Saudi Arabia.,Microbial Genetics Department, Agricultural Genetic Engineering Research Institute (AGERI), ARC, 12619, Giza, Egypt
| | - S E Hassanein
- Agriculture Genetic Engineering Research Institute (AGERI), Egypt.,Misr University for Science and Technology (MUST), October 6, Al Jizah, Egypt
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Soni P, Gangurde SS, Ortega-Beltran A, Kumar R, Parmar S, Sudini HK, Lei Y, Ni X, Huai D, Fountain JC, Njoroge S, Mahuku G, Radhakrishnan T, Zhuang W, Guo B, Liao B, Singam P, Pandey MK, Bandyopadhyay R, Varshney RK. Functional Biology and Molecular Mechanisms of Host-Pathogen Interactions for Aflatoxin Contamination in Groundnut ( Arachis hypogaea L.) and Maize ( Zea mays L.). Front Microbiol 2020; 11:227. [PMID: 32194520 PMCID: PMC7063101 DOI: 10.3389/fmicb.2020.00227] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/30/2020] [Indexed: 12/26/2022] Open
Abstract
Aflatoxins are secondary metabolites produced by soilborne saprophytic fungus Aspergillus flavus and closely related species that infect several agricultural commodities including groundnut and maize. The consumption of contaminated commodities adversely affects the health of humans and livestock. Aflatoxin contamination also causes significant economic and financial losses to producers. Research efforts and significant progress have been made in the past three decades to understand the genetic behavior, molecular mechanisms, as well as the detailed biology of host-pathogen interactions. A range of omics approaches have facilitated better understanding of the resistance mechanisms and identified pathways involved during host-pathogen interactions. Most of such studies were however undertaken in groundnut and maize. Current efforts are geared toward harnessing knowledge on host-pathogen interactions and crop resistant factors that control aflatoxin contamination. This study provides a summary of the recent progress made in enhancing the understanding of the functional biology and molecular mechanisms associated with host-pathogen interactions during aflatoxin contamination in groundnut and maize.
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Affiliation(s)
- Pooja Soni
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sunil S. Gangurde
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rakesh Kumar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sejal Parmar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Hari K. Sudini
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Yong Lei
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Xinzhi Ni
- Crop Genetics and Breeding Research Unit, United States Department of Agriculture – Agriculture Research Service, Tifton, GA, United States
| | - Dongxin Huai
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Jake C. Fountain
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
| | - Samuel Njoroge
- International Crops Research Institute for the Semi-Arid Tropics, Lilongwe, Malawi
| | - George Mahuku
- International Institute of Tropical Agriculture, Dar es Salaam, Tanzania
| | | | - Weijian Zhuang
- Oil Crops Research Institute, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Baozhu Guo
- Crop Protection and Management Research Unit, United States Department of Agriculture – Agricultural Research Service, Tifton, GA, United States
| | - Boshou Liao
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Prashant Singam
- Department of Genetics, Osmania University, Hyderabad, India
| | - Manish K. Pandey
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rajeev K. Varshney
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
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Mohamed MA, Abd-Elsalam KA. Nanoparticles and gene silencing for suppression of mycotoxins. NANOMYCOTOXICOLOGY 2020:423-448. [DOI: 10.1016/b978-0-12-817998-7.00018-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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Bandyopadhyay R, Atehnkeng J, Ortega-Beltran A, Akande A, Falade TDO, Cotty PJ. "Ground-Truthing" Efficacy of Biological Control for Aflatoxin Mitigation in Farmers' Fields in Nigeria: From Field Trials to Commercial Usage, a 10-Year Study. Front Microbiol 2019; 10:2528. [PMID: 31824438 PMCID: PMC6882503 DOI: 10.3389/fmicb.2019.02528] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/21/2019] [Indexed: 01/09/2023] Open
Abstract
In sub-Saharan Africa (SSA), diverse fungi belonging to Aspergillus section Flavi frequently contaminate staple crops with aflatoxins. Aflatoxins negatively impact health, income, trade, food security, and development sectors. Aspergillus flavus is the most common causal agent of contamination. However, certain A. flavus genotypes do not produce aflatoxins (i.e., are atoxigenic). An aflatoxin biocontrol technology employing atoxigenic genotypes to limit crop contamination was developed in the United States. The technology was adapted and improved for use in maize and groundnut in SSA under the trademark Aflasafe. Nigeria was the first African nation for which an aflatoxin biocontrol product was developed. The current study includes tests to assess biocontrol performance across Nigeria over the past decade. The presented data on efficacy spans years in which a relatively small number of maize and groundnut fields (8-51 per year) were treated through use on circa 36,000 ha in commercially-produced maize in 2018. During the testing phase (2009-2012), fields treated during one year were not treated in the other years while during commercial usage (2013-2019), many fields were treated in multiple years. This is the first report of a large-scale, long-term efficacy study of any biocontrol product developed to date for a field crop. Most (>95%) of 213,406 tons of maize grains harvested from treated fields contained <20 ppb total aflatoxins, and a significant proportion (>90%) contained <4 ppb total aflatoxins. Grains from treated plots had preponderantly >80% less aflatoxin content than untreated crops. The frequency of the biocontrol active ingredient atoxigenic genotypes in grains from treated fields was significantly higher than in grains from control fields. A higher proportion of grains from treated fields met various aflatoxin standards compared to grains from untreated fields. Results indicate that efficacy of the biocontrol product in limiting aflatoxin contamination is stable regardless of environment and cropping system. In summary, the biocontrol technology allows farmers across Nigeria to produce safer crops for consumption and increases potential for access to premium markets that require aflatoxin-compliant crops.
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Affiliation(s)
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture, Ibadan, Nigeria
| | | | | | | | - Peter J. Cotty
- Agricultural Research Service, United States Department of Agriculture, Tucson, AZ, United States
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9
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Han G, Zhao K, Yan X, Xiang F, Li X, Tao F. Differential regulation of mycelial growth and aflatoxin biosynthesis by Aspergillus flavus under different temperatures as revealed by strand-specific RNA-Seq. Microbiologyopen 2019; 8:e897. [PMID: 31328901 PMCID: PMC6813451 DOI: 10.1002/mbo3.897] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 06/06/2019] [Accepted: 06/10/2019] [Indexed: 11/11/2022] Open
Abstract
Although several regulatory pathways have been reported for Aspergillus flavus, the regulation of aflatoxin production and mycelial growth under different temperatures remains unclear. In this study, A. flavus differentially expressed genes (DEGs) and regulatory pathways were analyzed under three temperatures, by strand‐specific RNA‐Seq. Results show that a total of 2,428 and 1,474 DEGs were identified in fungal mycelia cultured at 20°C and 37°C, respectively, as compared with the control (28°C). Approximately ~ 79% of DEGs in the 37°C samples were up‐regulated genes, while ~ 63% of DEGs in the 20°C samples were down‐regulated genes. Most of the DEG pathways enriched by lower temperatures differed from those enriched by higher temperatures, while only a small portion of the pathways were shared by A. flavus grown under different temperatures. Aflatoxin biosynthesis, Butanoate metabolism, oxidation–reduction process, and benzene‐containing compound metabolic process were the shared down‐regulated pathways, while steroid biosynthesis, oxidoreductase activity, cellular protein modification process, DNA binding, protein complex were the shared up‐regulated pathways between lower and higher temperatures. The shared genes and pathways are the key regulatory candidates for aflatoxin biosynthesis with changes of temperature. In addition, the identification of both up‐regulated and down‐regulated genes provides a useful gene set for further investigation of the aflatoxin biosynthesis among Aspergillus.
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Affiliation(s)
- Guomin Han
- School of Life Sciences, Anhui Agricultural University, Hefei, China.,The National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei, China
| | - Kai Zhao
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Xiaodan Yan
- School of Management, Hefei University of Technology, Hefei, China
| | - Fangzhi Xiang
- School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Xuede Li
- School of Resources and Environment, Anhui Agricultural University, Hefei, China
| | - Fang Tao
- School of Life Sciences, Anhui Agricultural University, Hefei, China
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10
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Suwarno WB, Hannok P, Palacios-Rojas N, Windham G, Crossa J, Pixley KV. Provitamin A Carotenoids in Grain Reduce Aflatoxin Contamination of Maize While Combating Vitamin A Deficiency. FRONTIERS IN PLANT SCIENCE 2019; 10:30. [PMID: 30778360 PMCID: PMC6369730 DOI: 10.3389/fpls.2019.00030] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 01/09/2019] [Indexed: 05/25/2023]
Abstract
Aflatoxin contamination of maize grain and products causes serious health problems for consumers worldwide, and especially in low- and middle-income countries where monitoring and safety standards are inconsistently implemented. Vitamin A deficiency (VAD) also compromises the health of millions of maize consumers in several regions of the world including large parts of sub-Saharan Africa. We investigated whether provitamin A (proVA) enriched maize can simultaneously contribute to alleviate both of these health concerns. We studied aflatoxin accumulation in grain of 120 maize hybrids formed by crossing 3 Aspergillus flavus resistant and three susceptible lines with 20 orange maize lines with low to high carotenoids concentrations. The hybrids were grown in replicated, artificially-inoculated field trials at five environments. Grain of hybrids with larger concentrations of beta-carotene (BC), beta-cryptoxanthin (BCX) and total proVA had significantly less aflatoxin contamination than hybrids with lower carotenoids concentrations. Aflatoxin contamination had negative genetic correlation with BCX (-0.28, p < 0.01), BC (-0.18, p < 0.05), and proVA (-0.23, p < 0.05). The relative ease of breeding for increased proVA carotenoid concentrations as compared to breeding for aflatoxin resistance in maize suggests using the former as a component of strategies to combat aflatoxin contamination problems for maize. Our findings indicate that proVA enriched maize can be particularly beneficial where the health burdens of exposure to aflatoxin and prevalence of VAD converge with high rates of maize consumption.
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Affiliation(s)
- Willy B. Suwarno
- International Maize and Wheat Improvement Center, Texcoco, Mexico
- Department of Agronomy and Horticulture, Faculty of Agriculture, Bogor Agricultural University, Bogor, Indonesia
| | - Pattama Hannok
- International Maize and Wheat Improvement Center, Texcoco, Mexico
- Department of Agronomy, University of Wisconsin-Madison, Madison, WI, United States
| | | | - Gary Windham
- Corn Host Plant Resistance Research Unit, United States Department of Agriculture-Agricultural Research Service, Starkville, MS, United States
| | - José Crossa
- International Maize and Wheat Improvement Center, Texcoco, Mexico
| | - Kevin V. Pixley
- International Maize and Wheat Improvement Center, Texcoco, Mexico
- Department of Agronomy, University of Wisconsin-Madison, Madison, WI, United States
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11
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Cambaza E, Koseki S, Kawamura S. A Glance at Aflatoxin Research in Mozambique. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E1673. [PMID: 30087243 PMCID: PMC6121502 DOI: 10.3390/ijerph15081673] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 07/16/2018] [Accepted: 08/03/2018] [Indexed: 12/27/2022]
Abstract
In Mozambique, aflatoxin research started in the 1960's and has been carried through apparently unrelated efforts according to opportunities. However, they can be grouped in two sets: early epidemiological studies and recent agricultural research. Early investigators found a strong correlation between aflatoxin contamination and primary liver cancer. Since then, there have been efforts to examine the extent of contamination, especially in groundnuts and maize. More recent investigations and interventions aimed mostly to reduce the level of contamination, enough to allow such commodities to gain acceptance in the international market. The current status of knowledge is still marginal but the increasing involvement of local authorities, academia, and international organizations seems promising.
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Affiliation(s)
- Edgar Cambaza
- Laboratory of Agricultural and Food Process Engineering, Graduate School of Agriculture, Hokkaido University, Sapporo 060-0808, Japan.
- Department of Biological Sciences, Faculty of Sciences, Eduardo Mondlane University, Av. Julius Nyerere, nr. 3453 Maputo, Moçambique.
| | - Shigenobu Koseki
- Laboratory of Agricultural and Food Process Engineering, Graduate School of Agriculture, Hokkaido University, Sapporo 060-0808, Japan.
| | - Shuso Kawamura
- Laboratory of Agricultural and Food Process Engineering, Graduate School of Agriculture, Hokkaido University, Sapporo 060-0808, Japan.
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12
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Gilbert MK, Majumdar R, Rajasekaran K, Chen ZY, Wei Q, Sickler CM, Lebar MD, Cary JW, Frame BR, Wang K. RNA interference-based silencing of the alpha-amylase (amy1) gene in Aspergillus flavus decreases fungal growth and aflatoxin production in maize kernels. PLANTA 2018; 247:1465-1473. [PMID: 29541880 DOI: 10.1007/s00425-018-2875-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/01/2018] [Indexed: 05/22/2023]
Abstract
Expressing an RNAi construct in maize kernels that targets the gene for alpha-amylase in Aspergillus flavus resulted in suppression of alpha-amylase (amy1) gene expression and decreased fungal growth during in situ infection resulting in decreased aflatoxin production. Aspergillus flavus is a saprophytic fungus and pathogen to several important food and feed crops, including maize. Once the fungus colonizes lipid-rich seed tissues, it has the potential to produce toxic secondary metabolites, the most dangerous of which is aflatoxin. The pre-harvest control of A. flavus contamination and aflatoxin production is an area of intense research, which includes breeding strategies, biological control, and the use of genetically-modified crops. Host-induced gene silencing, whereby the host crop produces siRNA molecules targeting crucial genes in the invading fungus and targeting the gene for degradation, has shown to be promising in its ability to inhibit fungal growth and decrease aflatoxin contamination. Here, we demonstrate that maize inbred B104 expressing an RNAi construct targeting the A. flavus alpha-amylase gene amy1 effectively reduces amy1 gene expression resulting in decreased fungal colonization and aflatoxin accumulation in kernels. This work contributes to the development of a promising technology for reducing the negative economic and health impacts of A. flavus growth and aflatoxin contamination in food and feed crops.
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Affiliation(s)
- Matthew K Gilbert
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA.
| | - Rajtilak Majumdar
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Kanniah Rajasekaran
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Zhi-Yuan Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University Agricultural Center, 302 Life Science Building, Baton Rouge, LA, 70803, USA
| | - Qijian Wei
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Christine M Sickler
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Matthew D Lebar
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Jeffrey W Cary
- Food and Feed Safety Unit, Agricultural Research Service, USDA, 100 Robert E Lee Blvd., New Orleans, LA, 70124, USA
| | - Bronwyn R Frame
- Plant Transformation Facility, Iowa State University, G405 Agronomy Hall, Ames, IA, 50011, USA
| | - Kan Wang
- Plant Transformation Facility, Iowa State University, G405 Agronomy Hall, Ames, IA, 50011, USA
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13
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Rajasekaran K, Sayler RJ, Sickler CM, Majumdar R, Jaynes JM, Cary JW. Control of Aspergillus flavus growth and aflatoxin production in transgenic maize kernels expressing a tachyplesin-derived synthetic peptide, AGM182. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 270:150-156. [PMID: 29576068 DOI: 10.1016/j.plantsci.2018.02.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/28/2018] [Accepted: 02/07/2018] [Indexed: 06/08/2023]
Abstract
Aspergillus flavus is an opportunistic, saprophytic fungus that infects maize and other fatty acid-rich food and feed crops and produces toxic and carcinogenic secondary metabolites known as aflatoxins. Contamination of maize with aflatoxin poses a serious threat to human health in addition to reducing the crop value leading to a substantial economic loss. Here we report designing a tachyplesin1-derived synthetic peptide AGM182 and testing its antifungal activity both in vitro and in planta. In vitro studies showed a five-fold increase in antifungal activity of AGM182 (vs. tachyplesin1) against A. flavus. Transgenic maize plants expressing AGM182 under maize Ubiquitin-1 promoter were produced through Agrobacterium-mediated transformation. PCR products confirmed integration of the AGM182 gene, while RT-PCR of maize RNA confirmed the presence of AGM182 transcripts. Maize kernel screening assay using a highly aflatoxigenic A. flavus strain (AF70) showed up to 72% reduction in fungal growth in the transgenic AGM182 seeds compared to isogenic negative control seeds. Reduced fungal growth in the AGM182 transgenic seeds resulted in a significant reduction in aflatoxin levels (76-98%). The results presented here show the power of computational and synthetic biology to rationally design and synthesize an antimicrobial peptide against A. flavus that is effective in reducing fungal growth and aflatoxin contamination in an economically important food and feed crop such as maize.
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Affiliation(s)
- Kanniah Rajasekaran
- Food and Feed Safety Research Unit, USDA-ARS, Southern Regional Research Center, New Orleans, LA 70124, United States.
| | - Ronald J Sayler
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, United States
| | - Christine M Sickler
- Food and Feed Safety Research Unit, USDA-ARS, Southern Regional Research Center, New Orleans, LA 70124, United States
| | - Rajtilak Majumdar
- Food and Feed Safety Research Unit, USDA-ARS, Southern Regional Research Center, New Orleans, LA 70124, United States
| | - Jesse M Jaynes
- College of Agriculture, Environment and Nutrition Sciences, Tuskegee University, Tuskegee, AL 36088, United States
| | - Jeffrey W Cary
- Food and Feed Safety Research Unit, USDA-ARS, Southern Regional Research Center, New Orleans, LA 70124, United States
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14
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Machado AK, Brown NA, Urban M, Kanyuka K, Hammond‐Kosack KE. RNAi as an emerging approach to control Fusarium head blight disease and mycotoxin contamination in cereals. PEST MANAGEMENT SCIENCE 2018; 74:790-799. [PMID: 28967180 PMCID: PMC5873435 DOI: 10.1002/ps.4748] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/11/2017] [Accepted: 09/22/2017] [Indexed: 05/21/2023]
Abstract
Fusarium graminearum is a major fungal pathogen of cereals worldwide, causing seedling, stem base and floral diseases, including Fusarium head blight (FHB). In addition to yield and quality losses, FHB contaminates cereal grain with mycotoxins, including deoxynivalenol, which are harmful to human, animal and ecosystem health. Currently, FHB control is only partially effective due to several intractable problems. RNA interference (RNAi) is a natural mechanism that regulates gene expression. RNAi has been exploited in the development of new genomic tools that allow the targeted silencing of genes of interest in many eukaryotes. Host-induced gene silencing (HIGS) is a transgenic technology used to silence fungal genes in planta during attempted infection and thereby reduces disease levels. HIGS relies on the host plant's ability to produce mobile small interfering RNA molecules, generated from long double-stranded RNA, which are complementary to targeted fungal genes. These molecules are transferred from the plant to invading fungi via an uncharacterised mechanism, to cause gene silencing. Here, we describe recent advances in RNAi-mediated control of plant pathogenic fungi, highlighting the key advantages and disadvantages. We then discuss the developments and implications of combining HIGS with other methods of disease control. © 2017 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Ana Karla Machado
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Neil A Brown
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- Department of Biology & BiochemistryUniversity of Bath, Claverton DownBathUK
| | - Martin Urban
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Kostya Kanyuka
- Department of Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
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15
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Bhatnagar D, Rajasekaran K, Gilbert M, Cary J, Magan N. Advances in molecular and genomic research to safeguard food and feed supply from aflatoxin contamination. WORLD MYCOTOXIN J 2018. [DOI: 10.3920/wmj2017.2283] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Worldwide recognition that aflatoxin contamination of agricultural commodities by the fungus Aspergillus flavus is a global problem has significantly benefitted from global collaboration for understanding the contaminating fungus, as well as for developing and implementing solutions against the contamination. The effort to address this serious food and feed safety issue has led to a detailed understanding of the taxonomy, ecology, physiology, genomics and evolution of A. flavus, as well as strategies to reduce or control pre-harvest aflatoxin contamination, including (1) biological control, using atoxigenic aspergilli, (2) proteomic and genomic analyses for identifying resistance factors in maize as potential breeding markers to enable development of resistant maize lines, and (3) enhancing host-resistance by bioengineering of susceptible crops, such as cotton, maize, peanut and tree nuts. A post-harvest measure to prevent the occurrence of aflatoxin contamination in storage is also an important component for reducing exposure of populations worldwide to aflatoxins in food and feed supplies. The effect of environmental changes on aflatoxin contamination levels has recently become an important aspect for study to anticipate future contamination levels. The ability of A. flavus to produce dozens of secondary metabolites, in addition to aflatoxins, has created a new avenue of research for understanding the role these metabolites play in the survival and biodiversity of this fungus. The understanding of A. flavus, the aflatoxin contamination problem, and control measures to prevent the contamination has become a unique example for an integrated approach to safeguard global food and feed safety.
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Affiliation(s)
- D. Bhatnagar
- US Department of Agriculture, Agricultural Research Service, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA
| | - K. Rajasekaran
- US Department of Agriculture, Agricultural Research Service, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA
| | - M. Gilbert
- US Department of Agriculture, Agricultural Research Service, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA
| | - J.W. Cary
- US Department of Agriculture, Agricultural Research Service, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA
| | - N. Magan
- Applied Mycology Group, Cranfield University, MK45 4DT, Cranfield, United Kingdom
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