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Kim JH, Chan KL, Hart-Cooper WM, Palumbo JD, Orts WJ. High-efficiency fungal pathogen intervention for seed protection: new utility of long-chain alkyl gallates as heat-sensitizing agents. FRONTIERS IN FUNGAL BIOLOGY 2023; 4:1172893. [PMID: 37746121 PMCID: PMC10512402 DOI: 10.3389/ffunb.2023.1172893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 07/13/2023] [Indexed: 09/26/2023]
Abstract
Control of food-contaminating fungi, especially pathogens that produce mycotoxins, is problematic since effective method for intervening fungal infection on food crops is often limited. Generally Regarded As Safe (GRAS) chemicals, such as natural compounds or their structural derivatives, can be developed as antimicrobial agents for sustainable food/crop production. This study identified that long-chain alkyl gallates, i.e., octyl-, nonyl-, and decyl gallates (OG (octyl 3,4,5-trihydroxybenzoic acid), NG, DG), can function as heat-sensitizing agents that effectively prevent fungal contamination. Out of twenty-eight candidate compounds and six conventional antifungal agents examined, the heat-sensitizing capacity was unique to the long-chain alkyl gallates, where OG exhibited the highest activity, followed by DG and NG. Since OG is a GRAS compound classified by the United States Food and Drug Administration (FDA), further in vitro antifungal studies were performed using OG. When OG and mild heat (57.5°C) were co-administered for 90 seconds, the treatment achieved > 99.999% fungal death (> 5 log reduction). Application of either treatment alone was significantly less effective at reducing fungal survival. Of note, co-application of OG (3 mM) and mild heat (50°C) for 20 minutes completely prevented the survival of aflatoxigenic Aspergillus flavus contaminating crop seeds (Brassica rapa Pekinensis), while seed germination rate was unaffected. Heat-sensitization was also determined in selected bacterial strains (Escherichia coli, Agrobacterium tumefaciens). Altogether, OG is an effective heat-sensitizing agent for control of microbial pathogens. OG-mediated heat sensitization will improve the efficacy of antimicrobial practices, achieving safe, rapid, and cost-effective pathogen control in agriculture/food industry settings.
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Affiliation(s)
- Jong H. Kim
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Albany, CA, United States
| | - Kathleen L. Chan
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Albany, CA, United States
| | - William M. Hart-Cooper
- Bioproducts Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Albany, CA, United States
| | - Jeffrey D. Palumbo
- Foodborne Toxin Detection and Prevention Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Albany, CA, United States
| | - William J. Orts
- Bioproducts Research Unit, Western Regional Research Center, Agricultural Research Service, United States Department of Agriculture (USDA-ARS), Albany, CA, United States
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Mohsen E, El-Metwally MA, Ibrahim AA, Soliman MI. Impact of green antioxidants on decreasing the aflatoxins percentage in peanut oil seed ( Arachis hypogaea L.) during storage. Sci Prog 2023; 106:368504231176165. [PMID: 37226455 PMCID: PMC10450326 DOI: 10.1177/00368504231176165] [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] [Indexed: 05/26/2023]
Abstract
The present study conducted an experimental investigation to impede the degradation of peanut (Arachis hypogaea L.) seeds and enhance their quality while being stored. The efficacy of eco-friendly chemicals such as ascorbic acid, salicylic acid, acetic acid, and propionic acid in seed preservation was evaluated over a period of six months. After a period of six months of storage in a greenhouse, an examination was conducted on peanut seeds that had undergone treatment. Rhizoctonia was observed after Cephalothorax, whereas Aspergillus, Fusarium, and Penicillium were the prevailing fungi throughout the storage period. The optimal outcomes were obtained from the conversion of acetic acid to propionic acid. The study observed a decline in seed oil, protein, carbohydrates, germination percentage, energy, index, length, vigour index, dead and rotten seeds, rotted seedlings, and surviving healthy seedlings, with an increase in storage duration ranging from zero to six months. The application of 100% propionic acid to peanut seeds throughout the storage duration resulted in decreased occurrences of deceased seeds, decaying seeds, and deteriorated seedlings. Peanut seeds that underwent treatment with green chemical agents of moderate and high intensity were found to be free of aflatoxin B1. The highest levels of chlorophylls a and b, carotenoids, and total phenols were observed in seeds stored in greenhouses and treated with 100% propionic acid and acetic acid extract. The application of propionic acid 100%, acetic acid 100%, salicylic acid 4 g/l and ascorbic acid 4 g/l proved to be the most effective treatments for peanut seeds, exhibiting the lowest total aflatoxin level of 0.40. The correlation coefficient between shoot fresh weight and shoot dry weight was found to be 0.99, whereas the correlation coefficient between root dry weight and shoot length was 0.67. The seed chemical analysis, seedling characteristics, and germination characteristics were subjected to clustering analysis, resulting in the formation of two distinct groups. The first group consisted of germination percentage and energy levels across all time points (0-6 months), while the second group consisted of the remaining characteristics. The findings of this research propose the utilisation of 100% propionic acid as a viable method for preserving peanut seeds and preventing their deterioration during storage. The application of 100% acetic acid has been found to be effective in enhancing the quality of seeds and minimising losses.
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Affiliation(s)
- Esraa Mohsen
- Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt
| | - Mohamed A El-Metwally
- Mycological Research Department, Plant Pathology Research Institute, ARC, Giza, Egypt
| | - Amira A Ibrahim
- Botany and Microbiology Department, Faculty of Science, Al-Arish University, Al-Arish, Egypt
| | - Magda I Soliman
- Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt
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Resistance of Black Aspergilli Species from Grape Vineyards to SDHI, QoI, DMI, and Phenylpyrrole Fungicides. J Fungi (Basel) 2023; 9:jof9020221. [PMID: 36836335 PMCID: PMC9961879 DOI: 10.3390/jof9020221] [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: 01/24/2023] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
Fungicide applications constitute a management practice that reduces the size of fungal populations and by acting as a genetic drift factor, may affect pathogen evolution. In a previous study, we showed that the farming system influenced the population structure of the Aspergillus section Nigri species in Greek vineyards. The current study aimed to test the hypothesis that the differences in the population structure may be associated with the selection of fungicide-resistant strains within the black aspergilli populations. To achieve this, we determined the sensitivity of 102, 151, 19, and 22 for the A. uvarum, A. tubingensis, A. niger, and A. carbonarious isolates, respectively, originating either from conventionally-treated or organic vineyards to the fungicides fluxapyroxad-SDHIs, pyraclostrobin-QoIs, tebuconazole-DMIs, and fludioxonil-phenylpyrroles. The results showed widespread resistance to all four fungicides tested in the A. uvarum isolates originating mostly from conventional vineyards. In contrast, all the A. tubingensis isolates tested were sensitive to pyraclostrobin, while moderate frequencies of only lowly resistant isolates were identified for tebuconazole, fludioxonil, and fluxapyroxad. Sequencing analysis of the corresponding fungicide target encoding genes revealed the presence of H270Y, H65Q/S66P, and G143A mutations in the sdhB, sdhD, and cytb genes of A. uvarum resistant isolates, respectively. No mutations in the Cyp51A and Cyp51B genes were detected in either the A. uvarum or A. tubingensis isolates exhibiting high or low resistance levels to DMIs, suggesting that other resistance mechanisms are responsible for the observed phenotype. Our results support the initial hypothesis for the contribution of fungicide resistance in the black aspergilli population structure in conventional and organic vineyards, while this is the first report of A. uvarum resistance to SDHIs and the first documentation of H270Y or H65Q/S66P mutations in sdhB, sdhD, and of the G143A mutation in the cytb gene of this fungal species.
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Sun M, Wang H, Shi C, Li J, Cai L, Xiang L, Liu T, Goodwin PH, Chen X, Wang L. Effect of azoxystrobin on tobacco leaf microbial composition and diversity. FRONTIERS IN PLANT SCIENCE 2023; 13:1101039. [PMID: 36816485 PMCID: PMC9930646 DOI: 10.3389/fpls.2022.1101039] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/31/2022] [Indexed: 06/18/2023]
Abstract
Azoxystrobin, a quinone outside inhibitor fungicide, reduced tobacco target spot caused by Rhizoctonia solani by 62%, but also affected the composition and diversity of other microbes on the surface and interior of treated tobacco leaves. High-throughput sequencing showed that the dominant bacteria prior to azoxystrobin treatment were Methylobacterium on healthy leaves and Pseudomonas on diseased leaves, and the dominant fungi were Thanatephorous (teleomorph of Rhizoctonia) and Symmetrospora on healthy leaves and Thanatephorous on diseased leaves. Both bacterial and fungal diversity significantly increased 1 to 18 days post treatment (dpt) with azoxystrobin for healthy and diseased leaves. For bacteria on healthy leaves, the relative abundance of Pseudomonas, Sphingomonas, Unidentified-Rhizobiaceae and Massilia declined, while Methylobacterium and Aureimonas increased. On diseased leaves, the relative abundance of Sphingomonas and Unidentified-Rhizobiaceae declined, while Methylobacterium, Pseudomonas and Pantoea increased. For fungi on healthy leaves, the relative abundance of Thanatephorous declined, while Symmetrospora, Sampaiozyma, Plectosphaerella, Cladosporium and Cercospora increased. On diseased leaves, the relative abundance of Thanatephorous declined, while Symmetrospora, Sampaiozyma, Plectosphaerella, Cladosporium, Phoma, Pantospora and Fusarium, increased. Compared to healthy leaves, azoxystrobin treatment of diseased leaves resulted in greater reductions in Thanatephorous, Sphingomonas and Unidentified-Rhizobiaceae, a greater increase in Methylobacterium, and similar changes in Phoma, Fusarium, Plectosphaerella and Cladosporium. Azoxystrobin had a semi-selective effect altering the microbial diversity of the tobacco leaf microbiome, which could be due to factors, such as differences among bacterial and fungal species in sensitivity to quinone outside inhibitors, ability to use nutrients and niches as certain microbes are affected, and metabolic responses to azoxystrobin.
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Affiliation(s)
- Meili Sun
- College of Agriculture, Yangtze University, Jingzhou, Hubei, China
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Hancheng Wang
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Caihua Shi
- College of Agriculture, Yangtze University, Jingzhou, Hubei, China
| | - Jianjun Li
- College of Tropical Crops, Hainan University, Haikou, Hainan, China
| | - Liuti Cai
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Ligang Xiang
- College of Agriculture, Yangtze University, Jingzhou, Hubei, China
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Tingting Liu
- College of Agriculture, Yangtze University, Jingzhou, Hubei, China
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Paul H. Goodwin
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Xingjiang Chen
- Guizhou Provincial Academician Workstation of Microbiology and Health, Guizhou Academy of Tobacco Science, Guiyang, China
| | - Ling Wang
- Guizhou Bijie Tobacco Company, Bijie, Guizhou, China
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Food Toxicology and Food Safety: Report of the 3rd International Electronic Conference on Foods: Food, Microbiome, and Health-A Celebration of the 10th Anniversary of Foods' Impact on Our Wellbeing. Foods 2022; 11:foods11244099. [PMID: 36553841 PMCID: PMC9777875 DOI: 10.3390/foods11244099] [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: 12/01/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022] Open
Abstract
The purpose of the conference session summarized in this article was to bring together international experts on food toxicology and food safety and share the current scientific knowledge on these topics. The presentations covered a wide range of interdisciplinary issues, including (i) the impact of diet on body weight and health outcomes including results from animal models of carcinogenesis, (ii) methods for microbial oil extraction, (iii) food processing and its impact on food safety and health, (iv) novel compounds to avoid mycotoxin contamination of agricultural products, and (v) the safety of cannabidiol in food supplements based on Cannabis sativa extracts. Some of the conclusions of the presentations included that correct food choices may impact on the risk of non-communicable diseases such as cancer, that food processing may have an influence on health, by either reducing or increasing risks, and that research regarding novel compounds is important, which may have preventive but also detrimental effects on health.
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Characterization of the Aspergillus flavus Population from Highly Aflatoxin-Contaminated Corn in the United States. Toxins (Basel) 2022; 14:toxins14110755. [PMID: 36356005 PMCID: PMC9698142 DOI: 10.3390/toxins14110755] [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: 09/30/2022] [Revised: 10/23/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
Aflatoxin contamination of corn is a major threat to the safe food and feed. The United States Federal Grain Inspection Service (FGIS) monitors commercial grain shipments for the presence of aflatoxin. A total of 146 Aspergillus flavus were isolated from 29 highly contaminated grain samples to characterize the visual phenotypes, aflatoxin-producing potential, and genotypes to explore the etiological cause of high aflatoxin contamination of US corn. Five of the isolates had reduced sensitivity (43-49% resistant) to the fungicide azoxystrobin, with the remainder all being over 50% resistant to azoxystrobin at the discriminating dose of 2.5 µg/mL. Only six isolates of the highly aflatoxigenic S morphotype were found, and 48 isolates were non-aflatoxigenic. Analysis of the mating type locus revealed 45% MAT 1-1 and 55% MAT 1-2. The A. flavus population originating from the highly aflatoxin contaminated grain samples was compared to a randomly selected subset of isolates originating from commercial corn samples with typical levels of aflatoxin contamination (average < 50 ppb). Use of simple sequence repeat (SSR) genotyping followed by principal component analysis (PCoA) revealed a similar pattern of genotypic distribution in the two populations, but greater diversity in the FGIS-derived population. The noticeable difference between the two populations was that genotypes identical to strain NRRL 21882, the active component of the aflatoxin biocontrol product Afla-Guard™, were ten times more common in the commercial corn population of A. flavus compared to the population from the high-aflatoxin corn samples. The other similarities between the two populations suggest that high aflatoxin concentrations in corn grain are generally the result of infection with common A. flavus genotypes.
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Cosseboom SD, Hu M. Off-target selection of resistance to azoxystrobin in Aspergillus species associated with grape late season rots. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 188:105227. [PMID: 36464347 DOI: 10.1016/j.pestbp.2022.105227] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 09/02/2022] [Accepted: 09/06/2022] [Indexed: 06/17/2023]
Abstract
Due to recent evidence of Aspergillus uvarum pathogenicity on wine grapes and variable fungicide sensitivity to quinone outside inhibitor (QoI) fungicides, the identity and QoI sensitivity of Aspergillus isolates from the Mid-Atlantic United States was investigated. Phylogenic analysis of 31 isolates revealed 26 as A. uvarum and 5 as A. japonicus, both of which have been previously isolated from grape. The A. uvarum isolates had variable sensitivities to the QoI azoxystrobin, and the genomic region that codes for the target of QoIs, cytochrome b, was sequenced. Translation of the cytochrome b coding sequence revealed that the most resistant isolates (termed cytb3) contained three mutations, S108A, F129L, and A194V, and the moderately sensitive isolates (termed cytb2) contained two mutations S108A and A194V. This is the first report of an amino acid variation in cytochrome b at position 108. Cytb3 isolates were significantly less inhibited than the cytb2 and wild-type isolates (cytbWT) in vitro, and were significantly less inhibited than the cytbWT isolates on detached fruit. Molecular docking analysis revealed similar differences, with azoxystrobin binding most securely in the cytbWT variant of cytochrome b than cytb2 and cytb3. As Aspergillus rot has not been a target disease of fungicide sprays in the U.S., the selection of resistant phenotypes is likely resultant from sprays for other diseases. Resistance is of concern due to the pathogenicity of A. uvarum and A. japonicus on wine grapes, and the ability of these species to be mycotoxigenic or pathogenic for humans.
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Affiliation(s)
- Scott D Cosseboom
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, United States of America
| | - Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, United States of America.
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Sun D, Mao J, Wei H, Zhang Q, Cheng L, Yang X, Li P. Efficient Prevention of Aspergillus flavus Spores Spread in Air Using Plasmonic Ag-AgCl/α-Fe 2O 3 under Visible Light Irradiation. ACS APPLIED MATERIALS & INTERFACES 2022; 14:28021-28032. [PMID: 35675545 DOI: 10.1021/acsami.2c06963] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Aspergillus flavus is a kind of widespread fungi that can produce carcinogenic, teratogenic, and mutagenic secondary metabolites known as aflatoxins. Aspergillus flavus mainly spread through the means of fungal spores in air, thus preventing the spores spread is an effective strategy to control aflatoxins contamination from source. Herein, a rapid and efficient control way to prevent the spread of Aspergillus flavus spores in air was demonstrated. Ag-AgCl nanoparticles were combined with tetrahedral α-Fe2O3 to form plasmonic composites that presented 93.65 ± 1.53% prevention rate of Aspergillus flavus spores under 50 min visible light irradiation. The efficient activity was attributed to the synergy effect of Ag including intrinsic disinfection, electron sink, and localized surface plasmon resonance effect, which were proven by photoelectric characterization, density functional theory, and finite difference time domain methods. The calculated work functions of α-Fe2O3, Ag, and AgCl were 3.71, 4.52, and 5.38 eV, respectively, which could accelerate photoinduced carrier transfer through Ag during photoreaction. Moreover, it was found that the intrinsic disinfection of Ag and hydroxyl radical from photocatalytic reaction were the main factors to the prevention of Aspergillus flavus spores, which resulted in the destruction of spore structure and the leakage of intracellular protein with 62.15 ± 2.63 μg mL-1. Most important, it was proven that the composites also showed high activity (90.52 ± 1.26%) to prevent Aspergillus flavus spore spread in the storage process of peanuts. These findings not only provided useful information for an efficient and potential strategy to prevent Aspergillus flavus contamination but also could be as a reference in toxic fungi control.
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Affiliation(s)
- Di Sun
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Jin Mao
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Hailian Wei
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Qi Zhang
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Ling Cheng
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Xianglong Yang
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Peiwu Li
- National Reference Laboratory for Agricultural Testing, Key Laboratory of Detection for Mycotoxins, Laboratory of Quality & Safety Risk Assessment for Oilseed Products (Wuhan), Quality Inspection & Test Center for Oilseed Products, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China
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