1
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Tian X, Hu Y, Gao Y, Wang G, Tai B, Yang B, Xing F. Effects of Aspergillus flavus infection on multi-scale structures and physicochemical properties of maize starch during storage. Carbohydr Polym 2024; 342:122322. [PMID: 39048185 DOI: 10.1016/j.carbpol.2024.122322] [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: 02/16/2024] [Revised: 04/26/2024] [Accepted: 05/24/2024] [Indexed: 07/27/2024]
Abstract
This study systematically analyzed the effect of Aspergillus flavus infection on the maize starch multi-scale structure, physicochemical properties, processing characteristics, and synthesis regulation. A. flavus infection led to a decrease in the content of starch, an increase in the content of reactive oxygen species (ROS) and malondialdehyde (MDA), a significant decrease in the activities of peroxidase (POD) and superoxide dismutase (SOD). In addition, A. flavus infection had a significant destructive effect on the double helix structure, relative crystallinity and lamellar structure of starch, resulting in the reduction of starch viscosity, affecting the viscoelastic properties of starch, and complicating the gel formation process. However, the eugenol treatment group significantly inhibited the growth of A. flavus during maize storage, protecting the multi-scale structure and processing characteristics of maize starch from being damaged. Transcriptome analysis showed that genes involved in carbohydrate synthesis in maize were significantly downregulated and genes involved in energy synthesis were significantly upregulated, indicating that maize converted its energy storage into energy synthesis to fight the invasion of A. flavus. These results of this study enriched the mechanism of quality deterioration during maize storage, and provide theoretical and technical support for the prevention of A. flavus infection during maize storage.
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Affiliation(s)
- Xiaoyu Tian
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yafan Hu
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Yuan Gao
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Gang Wang
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Bowen Tai
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Bolei Yang
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
| | - Fuguo Xing
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
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2
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Calvo AM, Dabholkar A, Wyman EM, Lohmar JM, Cary JW. Beyond morphogenesis and secondary metabolism: function of Velvet proteins and LaeA in fungal pathogenesis. Appl Environ Microbiol 2024:e0081924. [PMID: 39230285 DOI: 10.1128/aem.00819-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024] Open
Abstract
Velvet proteins, as well as the epigenetic regulator LaeA, are conserved in numerous fungal species, where, in response to environmental cues, they control several crucial cellular processes, including sexual and asexual morphogenesis, secondary metabolism, response to oxidative stress, and virulence. During the last two decades, knowledge of their mechanism of action as well as understanding their functional roles, has greatly increased, particularly in Aspergillus species. Research efforts from multiple groups followed, leading to the characterization of other Velvet and LaeA homologs in species of other fungal genera, including important opportunistic plant and animal pathogens. This review focuses mainly on the current knowledge of the role of Velvet and LaeA function in fungal pathogenesis. Velvet proteins and LaeA are unique to fungi, and for this reason, additional knowledge of these critical regulatory proteins will be important in the development of targeted control strategies to decrease the detrimental impact of fungal pathogens capable of causing disease in plants and animals.
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Affiliation(s)
- Ana M Calvo
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Apoorva Dabholkar
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Elizabeth M Wyman
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Jessica M Lohmar
- Food and Feed Safety Research Unit, USDA/ARS, Southern Regional Research Center, New Orleans, Louisiana, USA
| | - Jeffrey W Cary
- Food and Feed Safety Research Unit, USDA/ARS, Southern Regional Research Center, New Orleans, Louisiana, USA
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3
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Nguyen TBH, Foulongne-Oriol M, Jany JL, le Floch G, Picot A. New insights into mycotoxin risk management through fungal population genetics and genomics. Crit Rev Microbiol 2024:1-22. [PMID: 39188135 DOI: 10.1080/1040841x.2024.2392179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 05/08/2024] [Accepted: 08/09/2024] [Indexed: 08/28/2024]
Abstract
Mycotoxin contamination of food and feed is a major global concern. Chronic or acute dietary exposure to contaminated food and feed can negatively affect both human and animal health. Contamination occurs through plant infection by toxigenic fungi, primarily Aspergillus and Fusarium spp., either before or after harvest. Despite the application of various management strategies, controlling these pathogens remains a major challenge primarily because of their ability to adapt to environmental changes and selection pressures. Understanding the genetic structure of plant pathogen populations is pivotal for gaining new insights into their biology and epidemiology, as well as for understanding the mechanisms behind their adaptability. Such deeper understanding is crucial for developing effective and preemptive management strategies tailored to the evolving nature of pathogenic populations. This review focuses on the population-level variations within the two most economically significant toxigenic fungal genera according to space, host, and pathogenicity. Outcomes in terms of migration patterns, gene flow within populations, mating abilities, and the potential for host jumps are examined. We also discuss effective yet often underutilized applications of population genetics and genomics to address practical challenges in the epidemiology and disease control of toxigenic fungi.
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Affiliation(s)
- Toan Bao Hung Nguyen
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Plouzané, France
| | | | - Jean-Luc Jany
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Plouzané, France
| | - Gaétan le Floch
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Plouzané, France
| | - Adeline Picot
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Plouzané, France
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4
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Yu M, Zhou X, Chen D, Jiao Y, Han G, Tao F. HacA, a key transcription factor for the unfolded protein response, is required for fungal development, aflatoxin biosynthesis and pathogenicity of Aspergillus flavus. Int J Food Microbiol 2024; 417:110693. [PMID: 38653122 DOI: 10.1016/j.ijfoodmicro.2024.110693] [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: 12/25/2023] [Revised: 03/16/2024] [Accepted: 04/02/2024] [Indexed: 04/25/2024]
Abstract
Aspergillus flavus is a fungus notorious for contaminating food and feed with aflatoxins. As a saprophytic fungus, it secretes large amounts of enzymes to access nutrients, making endoplasmic reticulum (ER) homeostasis important for protein folding and secretion. The role of HacA, a key transcription factor in the unfolded protein response pathway, remains poorly understood in A. flavus. In this study, the hacA gene in A. flavus was knockout. Results showed that the absence of hacA led to a decreased pathogenicity of the strain, as it failed to colonize intact maize kernels. This may be due to retarded vegetable growth, especially the abnormal development of swollen tips and shorter hyphal septa. Deletion of hacA also hindered conidiogenesis and sclerotial development. Notably, the mutant strain failed to produce aflatoxin B1. Moreover, compared to the wild type, the mutant strain showed increased sensitivity to ER stress inducer such as Dithiothreitol (DTT), and heat stress. It also displayed heightened sensitivity to other environmental stresses, including cell wall, osmotic, and pH stresses. Further transcriptomic analysis revealed the involvement of the hacA in numerous biological processes, including filamentous growth, asexual reproduction, mycotoxin biosynthetic process, signal transduction, budding cell apical bud growth, invasive filamentous growth, response to stimulus, and so on. Taken together, HacA plays a vital role in fungal development, pathogenicity and aflatoxins biosynthesis. This highlights the potential of targeting hacA as a novel approach for early prevention of A. flavus contamination.
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Affiliation(s)
- Min Yu
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
| | - Xiaoling Zhou
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
| | - Dongyue Chen
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
| | - Yuan Jiao
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China
| | - Guomin Han
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China; National Engineering Laboratory of Crop Stress Resistance Breeding, Anhui Agricultural University, Hefei 230036, China
| | - Fang Tao
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
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5
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Geng Q, Hu J, Xu P, Sun T, Qiu H, Wang S, Song F, Shen L, Li Y, Liu M, Peng X, Tian J, Yang K. The Autophagy-Related Protein ATG8 Orchestrates Asexual Development and AFB1 Biosynthesis in Aspergillus flavus. J Fungi (Basel) 2024; 10:349. [PMID: 38786704 PMCID: PMC11122632 DOI: 10.3390/jof10050349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/08/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
Autophagy, a conserved cellular recycling process, plays a crucial role in maintaining homeostasis under stress conditions. It also regulates the development and virulence of numerous filamentous fungi. In this study, we investigated the specific function of ATG8, a reliable autophagic marker, in the opportunistic pathogen Aspergillus flavus. To investigate the role of atg8 in A. flavus, the deletion and complemented mutants of atg8 were generated according to the homologous recombination principle. Deletion of atg8 showed a significant decrease in conidiation, spore germination, and sclerotia formation compared to the WT and atg8C strains. Additionally, aflatoxin production was found severely impaired in the ∆atg8 mutant. The stress assays demonstrated that ATG8 was important for A. flavus response to oxidative stress. The fluorescence microscopy showed increased levels of reactive oxygen species in the ∆atg8 mutant cells, and the transcriptional result also indicated that genes related to the antioxidant system were significantly reduced in the ∆atg8 mutant. We further found that ATG8 participated in regulating the pathogenicity of A. flavus on crop seeds. These results revealed the biological role of ATG8 in A. flavus, which might provide a potential target for the control of A. flavus and AFB1 biosynthesis.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Xue Peng
- JSNU-UWEC Joint Laboratory of Jiangsu Province Colleges and Universities, School of Life Science, Jiangsu Normal University, Xuzhou 221116, China; (Q.G.); (J.H.); (P.X.); (T.S.); (H.Q.); (S.W.); (F.S.); (L.S.); (Y.L.); (M.L.)
| | - Jun Tian
- JSNU-UWEC Joint Laboratory of Jiangsu Province Colleges and Universities, School of Life Science, Jiangsu Normal University, Xuzhou 221116, China; (Q.G.); (J.H.); (P.X.); (T.S.); (H.Q.); (S.W.); (F.S.); (L.S.); (Y.L.); (M.L.)
| | - Kunlong Yang
- JSNU-UWEC Joint Laboratory of Jiangsu Province Colleges and Universities, School of Life Science, Jiangsu Normal University, Xuzhou 221116, China; (Q.G.); (J.H.); (P.X.); (T.S.); (H.Q.); (S.W.); (F.S.); (L.S.); (Y.L.); (M.L.)
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6
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Rasheed U, Cotty PJ, Ain QU, Wang Y, Liu B. Efficacy of atoxigenic Aspergillus flavus from southern China as biocontrol agents against aflatoxin contamination in corn and peanuts. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 201:105887. [PMID: 38685218 DOI: 10.1016/j.pestbp.2024.105887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/23/2024] [Accepted: 03/24/2024] [Indexed: 05/02/2024]
Abstract
Aspergillus flavus is a ubiquitous facultative pathogen that routinely infects important crops leading to formation of aflatoxins during crop development and after harvest. Corn and peanuts in warm and/or drought-prone regions are highly susceptible to aflatoxin contamination. Controlling aflatoxin using atoxigenic A. flavus is a widely adopted strategy. However, no A. flavus genotypes are currently approved for use in China. The current study aimed to select atoxigenic A. flavus endemic to Guangxi Zhuang Autonomous Region with potential as active ingredients of aflatoxin biocontrol products. A total of 204 A. flavus isolates from corn, peanuts, and field soil were evaluated for ability to produce the targeted mycotoxins. Overall, 57.3% could not produce aflatoxins while 17.15% were incapable of producing both aflatoxins and CPA. Atoxigenic germplasm endemic to Guangxi was highly diverse, yielding 8 different gene deletion patterns in the aflatoxin and CPA biosynthesis gene clusters ranging from no deletion to deletion of both clusters. Inoculation of corn and peanuts with both an aflatoxin producer and selected atoxigenic genotypes showed significant reduction (74 to 99%) in aflatoxin B1 (AFB1) formation compared with inoculation with the aflatoxin producer alone. Atoxigenic genotypes also efficiently degraded AFB1 (61%). Furthermore, atoxigenic isolates were also highly efficient at reducing aflatoxin concentrations even when present at lower concentrations than aflatoxin producers. The use of multiple atoxigenics was not always as effective as the use of a single atoxigenic. Effective atoxigenic genotypes of A. flavus with known mechanisms of atoxigenicity are demonstrated to be endemic to Southern China. These A. flavus may be utilized as active ingredients of biocontrol products without concern for detrimental impacts that may result from introduction of exotic fungi. Field efficacy trials in the agroecosystems of Southern China are needed to determine the extent to which such products may allow the production of safer food and feed.
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Affiliation(s)
- Usman Rasheed
- Institute of Applied Microbiology, College of Agriculture, Guangxi University, Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning 530004, China
| | - Peter J Cotty
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China
| | - Qurat Ul Ain
- Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology, School of Chemistry and Chemical Engineering, Guangxi University, Nanning, China
| | - YiFan Wang
- Institute of Applied Microbiology, College of Agriculture, Guangxi University, Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning 530004, China
| | - Bin Liu
- Institute of Applied Microbiology, College of Agriculture, Guangxi University, Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Nanning 530004, China.
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7
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Son YE, Park HS. SscA is required for fungal development, aflatoxin production, and pathogenicity in Aspergillus flavus. Int J Food Microbiol 2024; 413:110607. [PMID: 38308877 DOI: 10.1016/j.ijfoodmicro.2024.110607] [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: 12/14/2023] [Revised: 01/16/2024] [Accepted: 01/23/2024] [Indexed: 02/05/2024]
Abstract
Fungal spores are specialized dormant cells that act as primary reproductive biological particles and exhibit strong viability under extremely harsh conditions. They contaminate a variety of crops and foods, causing severe health hazards to humans and animals. Previous studies demonstrated that a spore-specific transcription factor SscA plays pivotal roles in the conidiogenesis of the model organism Aspergillus nidulans. In this study, we investigated the biological and genetic functions of SscA in the aflatoxin-producing fungus A. flavus. Deletion of sscA showed reduced conidia formation, lost long-term viability, and exhibited more sensitivity to thermal, oxidative, and radiative stresses. The sscA-deficient strain showed increased aflatoxin B1 production in conidia as well as mycelia. Importantly, the absence of sscA affected fungal pathogenicity on crops. Further transcriptomic and phenotypic studies suggested that SscA coordinates conidial wall structures. Overall, SscA is important for conidial formation, maturation and dormancy, mycotoxin production, and pathogenicity in A. flavus.
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Affiliation(s)
- Ye-Eun Son
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Hee-Soo Park
- School of Food Science and Biotechnology, Kyungpook National University, Daegu 41566, Republic of Korea; Department of Integrative Biology, Kyungpook National University, Daegu 41566, Republic of Korea.
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8
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Nji QN, Babalola OO, Mwanza M. Soil Aspergillus Species, Pathogenicity and Control Perspectives. J Fungi (Basel) 2023; 9:766. [PMID: 37504754 PMCID: PMC10381279 DOI: 10.3390/jof9070766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/05/2023] [Accepted: 07/18/2023] [Indexed: 07/29/2023] Open
Abstract
Five Aspergillus sections have members that are established agricultural pests and producers of different metabolites, threatening global food safety. Most of these pathogenic Aspergillus species have been isolated from almost all major biomes. The soil remains the primary habitat for most of these cryptic fungi. This review explored some of the ecological attributes that have contributed immensely to the success of the pathogenicity of some members of the genus Aspergillus over time. Hence, the virulence factors of the genus Aspergillus, their ecology and others were reviewed. Furthermore, some biological control techniques were recommended. Pathogenic effects of Aspergillus species are entirely accidental; therefore, the virulence evolution prediction model in such species becomes a challenge, unlike their obligate parasite counterparts. In all, differences in virulence among organisms involved both conserved and species-specific genetic factors. If the impacts of climate change continue, new cryptic Aspergillus species will emerge and mycotoxin contamination risks will increase in all ecosystems, as these species can metabolically adjust to nutritional and biophysical challenges. As most of their gene clusters are silent, fungi continue to be a source of underexplored bioactive compounds. The World Soil Charter recognizes the relevance of soil biodiversity in supporting healthy soil functions. The question of how a balance may be struck between supporting healthy soil biodiversity and the control of toxic fungi species in the field to ensure food security is therefore pertinent. Numerous advanced strategies and biocontrol methods so far remain the most environmentally sustainable solution to the control of toxigenic fungi in the field.
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Affiliation(s)
- Queenta Ngum Nji
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Olubukola Oluranti Babalola
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
| | - Mulunda Mwanza
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
- Department of Animal Health, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2735, South Africa
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9
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Jin J, Diao Y, Xiong X, Yu C, Tian Y, Li C, Liu H. The Regulation of the Growth and Pathogenicity of Valsa mali by the Carbon Metabolism Repressor CreA. Int J Mol Sci 2023; 24:ijms24119252. [PMID: 37298203 DOI: 10.3390/ijms24119252] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 05/18/2023] [Accepted: 05/18/2023] [Indexed: 06/12/2023] Open
Abstract
Carbon catabolite repression (CCR) is a very important mechanism for efficient use of carbon sources in the environment and is necessary for the regulation of fungal growth, development, and pathogenesis. Although there have been extensive studies conducted regarding this mechanism in fungi, little is yet known about the effects of CreA genes on Valsa mali. However, based on the results obtained in this study for the identification of the VmCreA gene in V. mali, it was determined that the gene was expressed at all stages of fungal growth, with self-repression observed at the transcriptional level. Furthermore, the functional analysis results of the gene deletion mutants (ΔVmCreA) and complements (CTΔVmCreA) showed that the VmCreA gene played an important role in the growth, development, pathogenicity, and carbon source utilization of V. mali.
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Affiliation(s)
- Jiyang Jin
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Yufei Diao
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Xiong Xiong
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Chengming Yu
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Yehan Tian
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Chuanrong Li
- Mountain Tai Forest Ecosystem Research Station of State Forestry Administration, Key Laboratory of Ecological Protection and Safety Prevention of the Lower Yellow River, Forestry College, Shandong Agricultural University, Tai'an 271018, China
| | - Huixiang Liu
- Shandong Research Center for Forestry Harmful Biological Control Engineering and Technology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
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10
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Geweely NS, Soliman MM, Ali RA, Hassaneen HM, Abdelhamid IA. Novel eco-friendly [1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives efficiency against fungal deterioration of ancient Egyptian mummy cartonnage, Egypt. Arch Microbiol 2023; 205:57. [PMID: 36609727 PMCID: PMC9825552 DOI: 10.1007/s00203-022-03395-7] [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: 05/14/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/09/2023]
Abstract
Fungal deterioration is one of the major factors that significantly contribute to mummy cartonnage damage. Isolation and molecular identification of thirteen fungal species contributing to the deterioration of ancient Egyptian mummy cartonnage located in El-Lahun regions, Fayoum government, Egypt was performed. The most dominant deteriorated fungal species are Aspergillus flavus (25.70%), Aspergillus terreus (16.76%), followed by A. niger (13.97%). A newly synthesized series of tetrahydro-[1,2,4]triazolo[3,4-a]isoquinoline chalcone derivatives were synthesized and evaluated for their antifungal activities in vitro against the isolated deteriorated fungal species (Aspergillus flavus, A. niger, A. terreus, Athelia bombacina, Aureobasidium iranianum, Byssochlamys spectabilis, Cladosporium cladosporioides, C. ramotenellum, Penicillium crustosum, P. polonicum, Talaromyces atroroseus, T. minioluteus and T. purpureogenus). The most efficient chalcone derivatives are new chalcone derivative numbers 9 with minimum inhibitory concentration (MIC) ranging from 1 to 3 mg/mL followed by chalcone derivatives number 5 with MIC ranging from 1 to 4 mg/mL.
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Affiliation(s)
- Neveen S. Geweely
- grid.7776.10000 0004 0639 9286Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza, 12613 Egypt
| | - Mona M. Soliman
- grid.7776.10000 0004 0639 9286Department of Botany and Microbiology, Faculty of Science, Cairo University, Giza, 12613 Egypt
| | - Rania A. Ali
- Department of Mummies and Human Remains Conservation, Central Department of Conservation and Restoration, Project Sector, Ministry of Tourism and Antiquities, Cairo, Egypt
| | - Hamdi M. Hassaneen
- grid.7776.10000 0004 0639 9286Department of Chemistry, Faculty of Science, Cairo University, Giza, 12613 Egypt
| | - Ismail A. Abdelhamid
- grid.7776.10000 0004 0639 9286Department of Chemistry, Faculty of Science, Cairo University, Giza, 12613 Egypt
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11
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Zhuang Z, Pan X, Zhang M, Liu Y, Huang C, Li Y, Hao L, Wang S. Set2 family regulates mycotoxin metabolism and virulence via H3K36 methylation in pathogenic fungus Aspergillus flavus. Virulence 2022; 13:1358-1378. [PMID: 35943142 PMCID: PMC9364737 DOI: 10.1080/21505594.2022.2101218] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aspergillus flavus infects various crops with aflatoxins, and leads to aspergillosis opportunistically. Though H3K36 methylation plays an important role in fungal toxin metabolism and virulence, no data about the biological function of H3K36 methylation in A. flavus virulence has been reported. Our study showed that the Set2 histone methyltransferase family, AshA and SetB, involves in morphogenesis and mycotoxin anabolism by regulating related transcriptional factors, and they are important for fungal virulence to crops and animals. Western-blotting and double deletion analysis revealed that AshA mainly regulates H3K36me2, whereas SetB is mainly responsible for H3K36me3 in the nucleus. By construction of domain deletion A. flavus strain and point mutation strains by homologous recombination, the study revealed that SET domain is indispensable in mycotoxin anabolism and virulence of A. flavus, and N455 and V457 in it are the key amino acid residues. ChIP analysis inferred that the methyltransferase family controls fungal reproduction and regulates the production of AFB1 by directly regulating the production of the transcriptional factor genes, including wetA, steA, aflR and amylase, through H3K36 trimethylation in their chromatin fragments, based on which this study proposed that, by H3K36 trimethylation, this methyltransferase family controls AFB1 anabolism through transcriptional level and substrate utilization level. This study illuminates the epigenetic mechanism of the Set2 family in regulating fungal virulence and mycotoxin production, and provides new targets for controlling the virulence of the fungus A. flavus.
AUTHOR SUMMARY
The methylation of H3K36 plays an important role in the fungal secondary metabolism and virulence, but no data about the regulatory mechanism of H3K36 methylation in the virulence of A. flavus have been reported. Our study revealed that, in the histone methyltransferase Set2 family, AshA mainly catalyzes H3K36me2, and involves in the methylation of H3K36me1, and SetB mainly catalyzes H3K36me3 and H3K36me1. Through domain deletion and point mutation analysis, this study also revealed that the SET domain was critical for the normal biological function of the Set2 family and that N455 and V457 in the domain were critical for AshA. By ChIP-seq and ChIP-qPCR analysis, H3K36 was found to be trimethylation modified in the promotors and ORF positions of wetA, steA, aflR and the amylase gene (AFLA_084340), and further qRT-PCR results showed that these methylation modifications regulate the expression levels of these genes. According to the results of ChIP-seq analysis, we proposed that, by H3K36 trimethylation, this methyltransferase family controls the metabolism of mycotoxin through transcriptional level and substrate utilization level. All the results from this study showed that Set2 family is essential for fungal secondary metabolism and virulence, which lays a theoretical groundwork in the early prevention and treatment of A. flavus pollution, and also provides an effective strategy to fight against other pathogenic fungi.
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Affiliation(s)
- Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xiaohua Pan
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China.,Fujian Key Laboratory of Propagated Sensation along Meridian, Fujian Academy of Chinese Medical Sciences, Fuzhou, China
| | - Mengjuan Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yaju Liu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Chuanzhong Huang
- Immuno-Oncology Laboratory of Fujian Cancer Hospital, Fujian Provincial Key Laboratory of Translational Cancer Medicine, Fujian Medical University Cancer Hospital, Fuzhou, China
| | - Yu Li
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Ling Hao
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, China
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12
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Wang Y, Lin W, Yan H, Neng J, Zheng Y, Yang K, Xing F, Sun P. iTRAQ proteome analysis of the antifungal mechanism of citral on mycelial growth and OTA production in Aspergillus ochraceus. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2021; 101:4969-4979. [PMID: 33543481 DOI: 10.1002/jsfa.11140] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 12/28/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND Aspergillus ochraceus causes food spoilage and produces mycotoxin ochratoxin A (OTA) during storage of agricultural commodities. In this study, citral was used to inhibit A. ochraceus growth and OTA accumulation, proteomic analysis was employed to verify the mechanism of citral. RESULTS Citral was found to significantly inhibit fungal growth and mycotoxin production in A. ochraceus. Specifically, 75, 125, 150 and 200 μL L-1 citral suppressed mycelial growth by 33%, 46%, 50% and 100%, respectively. Additionally, 75 μL L-1 citral inhibited OTA accumulation by 25%. Proteomic analysis was performed to elucidate the inhibitory mechanism of citral on mycelial growth and OTA production at subinhibitory concentrations (75 μL L-1 ). Proteomics analysis identified 2646 proteins in A. ochraceus fc-1, of which 218 were differentially expressed between control and 75 μL L-1 citral treatment samples. Differentially expressed proteins were identified by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of biological process, cellular component and molecular function terms. Potential factors affecting mycelial growth and OTA production were analysed, and OTA production was revealed to be a complex process involving many associated factors related to various processes including nutrient intake, sterol biosynthesis, ribosome biogenesis, energy metabolism, oxidative stress and amino acid metabolism. In addition, citral at 75 μL L-1 down-regulated OTA biosynthetic genes including pks and nrps, but slightly up-regulated the global regulatory factors veA, velB and laeA. CONCLUSION The findings further demonstrate the potential of citral for the preservation of grains and other agricultural products, and provide new insight into its antifungal mechanisms at subinhibitory concentrations. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Yan Wang
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
| | - Wei Lin
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
| | - Hao Yan
- Zhejiang Provincial Centre for Disease Control and Prevention, Hangzhou, China
| | - Jing Neng
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
| | - Yong Zheng
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
| | - Kai Yang
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Beijing, China
| | - Peilong Sun
- College of Food Science and Technology, Zhejiang University of Technology/Key Laboratory of Food Macromolecular Resources Processing Technology Research (Zhejiang University of Technology), China National Light Industry, Hangzhou, China
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13
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Alvarez-Zúñiga MT, Castañeda García D, Aguilar Osorio G. Effect of different carbon sources on the growth and enzyme production of a toxigenic and a non-toxigenic strain of Aspergillus flavus. Prep Biochem Biotechnol 2020; 51:769-779. [DOI: 10.1080/10826068.2020.1858426] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- María Teresa Alvarez-Zúñiga
- Department of Food Science and Biotechnology, Faculty of Chemistry, National Autonomous University of Mexico, Coyoacan, Mexico
| | - Diana Castañeda García
- Department of Food Science and Biotechnology, Faculty of Chemistry, National Autonomous University of Mexico, Coyoacan, Mexico
| | - Guillermo Aguilar Osorio
- Department of Food Science and Biotechnology, Faculty of Chemistry, National Autonomous University of Mexico, Coyoacan, Mexico
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14
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Mills B, Radhakrishnan N, Karthikeyan Rajapandian SG, Rameshkumar G, Lalitha P, Prajna NV. The role of fungi in fungal keratitis. Exp Eye Res 2020; 202:108372. [PMID: 33249061 DOI: 10.1016/j.exer.2020.108372] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/07/2020] [Accepted: 11/22/2020] [Indexed: 12/20/2022]
Abstract
Fungal keratitis (FK) accounts for approximately half of the microbial keratitis encountered in low middle income countries (LMICs) and predominantly affect the working rural-poor. FK causes significant morbidity with the majority of patients left with moderate or worse visual impairment and approximately 25% requiring expensive and often unsuccessful surgical interventions. The severity of FK and the resultant corneal damage or resolution can be attributed to i) the virulence and bioburden of the fungal pathogen, ii) the host defense mechanism and immune response and iii) sub-optimal diagnostics and anti-fungal treatment strategies. This review provides a comprehensive overview of the multifaceted components that drive FK progression and resolution, highlighting where knowledge gaps exist and areas that warrant further research.
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Affiliation(s)
- Bethany Mills
- Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, UK
| | - Naveen Radhakrishnan
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India
| | | | | | - Prajna Lalitha
- Department of Ocular Microbiology, Aravind Eye Hospital, Madurai, India
| | - N Venkatesh Prajna
- Department of Cornea and Refractive Surgery, Aravind Eye Hospital, Madurai, India.
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Soil-Biodegradable Plastic Mulches Undergo Minimal in-Soil Degradation in a Perennial Raspberry System after 18 Months. HORTICULTURAE 2020. [DOI: 10.3390/horticulturae6030047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Soil-biodegradable plastic mulches (BDMs) are made from biodegradable materials that can be bio-based, synthetic, or a blend of these two types of polymers, which are designed to degrade in soil through microbial activities. The purpose of BDMs is to reduce agricultural plastic waste by replacing polyethylene (PE) mulch, which is not biodegradable. Most studies have evaluated the breakdown of BDMs within annual production systems, but knowledge of BDM breakdown in perennial systems is limited. The objective of this study was to evaluate the deterioration and degradation of BDMs in a commercial red raspberry (Rubus ideaus L.) production system. Deterioration was low (≤11% percent soil exposure; PSE) for all mulches until October 2017 (five months after transplanting, MAT). By March 2018 (10 MAT), deterioration reached 91% for BDMs but remained low for PE mulch (4%). Mechanical strength also was lower for BDMs than PE mulch. In a soil burial test in the raspberry field, 91% of the BDM area remained after 18 months. In-soil BDM degradation was minimal, although the PSE was high. Since mulch is only applied once in a perennial crop production system, and the lifespan of the planting may be three or more years, it is worth exploring the long-term degradation of BDMs in perennial cropping systems across diverse environments.
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Critical thresholds of 1-Octen-3-ol shape inter-species Aspergillus interactions modulating the growth and secondary metabolism. Sci Rep 2020; 10:11116. [PMID: 32632328 PMCID: PMC7338521 DOI: 10.1038/s41598-020-68096-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 06/16/2020] [Indexed: 12/12/2022] Open
Abstract
In fungi, contactless interactions are mediated via the exchange of volatile organic compounds (VOCs). As these pair-wise interactions are fundamental to complex ecosystem, we examined the effects of inter-species VOCs trade-offs in Aspergillus flavus development. First, we exposed A. flavus to the A. oryzae volatilome (Treatment-1) with highest relative abundance of 1-Octen-3-ol (~ 4.53 folds) among the C-8 VOCs. Further, we examined the effects of gradient titers of 1-Octen-3-ol (Treatment-2: 100–400 ppm/day) in a range that elicits natural interactions. On 7-day, VOC-treated A. flavus displayed significantly reduced growth and sclerotial counts (p < 0.01) coupled with higher conidial density (T2100-200 ppm/day, p < 0.01) and α-amylase secretion (T2200 ppm/day, p < 0.01), compared to the untreated sets. Similar phenotypic trends except for α-amylases were evident for 9-day incubated A. flavus in T2. The corresponding metabolomics data displayed a clustered pattern of secondary metabolite profiles for VOC-treated A. flavus (PC1-18.03%; PC2-10.67%). Notably, a higher relative abundance of aflatoxin B1 with lower levels of most anthraquinones, indole-terpenoids, and oxylipins was evident in VOC-treated A. flavus. The observed correlations among the VOC-treatments, phenotypes, and altered metabolomes altogether suggest that the distant exposure to the gradient titers of 1-Octen-3-ol elicits an attenuated developmental response in A. flavus characterized by heightened virulence.
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17
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Oliveira RC, Carvajal-Moreno M, Correa B, Rojo-Callejas F. Cellular, physiological and molecular approaches to investigate the antifungal and anti-aflatoxigenic effects of thyme essential oil on Aspergillus flavus. Food Chem 2020; 315:126096. [DOI: 10.1016/j.foodchem.2019.126096] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 11/08/2019] [Accepted: 12/21/2019] [Indexed: 10/25/2022]
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18
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Jediyi H, Naamani K, Ait Elkoch A, Dihazi A, Lemjiber N. A comparative study of phenols composition, antioxidant, and antifungal potency of leaves extract from five Moroccan
Vitis vinifera
L. varieties. J Food Saf 2020. [DOI: 10.1111/jfs.12756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hicham Jediyi
- Laboratory of Protection and Valorization of Vegetable Resources, Faculty of Sciences Semlalia MarrakechCadi Ayyad University Marrakesh Morocco
| | - Khalid Naamani
- Laboratory of Protection and Valorization of Vegetable Resources, Faculty of Sciences Semlalia MarrakechCadi Ayyad University Marrakesh Morocco
| | - Abderrahim Ait Elkoch
- Laboratory of Protection and Valorization of Vegetable Resources, Faculty of Sciences Semlalia MarrakechCadi Ayyad University Marrakesh Morocco
| | - Abdelhey Dihazi
- Laboratory of Protection and Valorization of Vegetable Resources, Faculty of Sciences Semlalia MarrakechCadi Ayyad University Marrakesh Morocco
| | - Naima Lemjiber
- Laboratory of Protection and Valorization of Vegetable Resources, Faculty of Sciences Semlalia MarrakechCadi Ayyad University Marrakesh Morocco
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Oliveira RC, Carvajal-Moreno M, Mercado-Ruaro P, Rojo-Callejas F, Correa B. Essential oils trigger an antifungal and anti-aflatoxigenic effect on Aspergillus flavus via the induction of apoptosis-like cell death and gene regulation. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.107038] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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20
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Torres-Barajas LR, Alvarez-Zúñiga MT, Mendoza-Hernández G, Aguilar-Osorio G. Analysis of polysaccharide hydrolases secreted by Aspergillus flavipes FP-500 on corn cobs and wheat bran as complex carbon sources. Prep Biochem Biotechnol 2019; 50:390-400. [DOI: 10.1080/10826068.2019.1700518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Lizzete Ruth Torres-Barajas
- Department of Food Science and Biotechnology, Faculty of Chemistry, National Autonomous University of Mexico, Coyoacan, Mexico
| | - María Teresa Alvarez-Zúñiga
- Department of Food Science and Biotechnology, Faculty of Chemistry, National Autonomous University of Mexico, Coyoacan, Mexico
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21
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Wang P, Chang PK, Kong Q, Shan S, Wei Q. Comparison of aflatoxin production of Aspergillus flavus at different temperatures and media: Proteome analysis based on TMT. Int J Food Microbiol 2019; 310:108313. [DOI: 10.1016/j.ijfoodmicro.2019.108313] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/13/2019] [Accepted: 08/23/2019] [Indexed: 01/10/2023]
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22
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Naz F, Anis H, Hasan Z, Islam A, Khan LA. Exploration of Fungal Lipase as Direct Target of Eugenol through Spectroscopic Techniques. Protein Pept Lett 2019; 26:919-929. [PMID: 31057096 DOI: 10.2174/0929866526666190506113455] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 03/13/2019] [Accepted: 04/19/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Fungal lipase dependent processes are important for their pathogenicity. Lipases can therefore be explored as direct target of promising herbal antifungals. OBJECTIVE We explored Aspergillus niger lipase as a direct target of eugenol through spectroscopic techniques and compare results with Bovine Serum Albumin and lysozyme to comment on selectivity of eugenol towards lipase. METHODS In vitro activity assays of lipase are used to determine concentration ranges. UV-Visible, Fluorescence and Circular dichroism spectroscopy were employed to determine binding constant, stoichiometric binding sites and structural changes in Lipase, BSA and lysozyme following incubation with varying concentrations of eugenol. RESULTS In activity assays 50% inhibition of lipase was obtained at 0.913 mmoles/litre eugenol. UV-vis spectroscopy shows formation of lipase-eugenol, Bovine Serum Albumin-eugenol and lysozyme-eugenol complex well below this concentration of eugenol. Eugenol binding caused blue shift with Bovine Serum Albumin and lysozyme suggestive of compaction, and red shift with lipase. Negative ellipticity decreased with lipase but increased with Bovine Serum Albumineugenol and lysozyme-eugenol complexes suggesting loss of helical structure for lipase and compaction for Bovine Serum Albumin and lysozyme. Binding of eugenol to lipase was strong (Ka= 4.7 x 106 M-1) as compared to Bovine Serum Albumin and lysozyme. The number of stoichiometric eugenol binding sites on lipase was found to be 2 as compared to 1.37 (Bovine Serum Albumin) and 0.32 (lysozyme). Docking results also suggest strong binding of eugenol with lipase followed by Bovine Serum Albumin and lysozyme. CONCLUSION Eugenol is found to be effective inhibitor and disruptor of secondary and tertiary structure of lipase, whereas its binding to Bovine Serum Albumin and lysozyme is found to be weak and less disruptive of structures suggesting selectivity of eugenol towards lipase.
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Affiliation(s)
- Farheen Naz
- Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Haider Anis
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Ziaul Hasan
- Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Luqman A Khan
- Department of Biosciences, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi 110025, India
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The Aspergillus flavus rtfA Gene Regulates Plant and Animal Pathogenesis and Secondary Metabolism. Appl Environ Microbiol 2019; 85:AEM.02446-18. [PMID: 30635379 DOI: 10.1128/aem.02446-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 12/31/2018] [Indexed: 02/04/2023] Open
Abstract
Aspergillus flavus is an opportunistic fungal plant and human pathogen and a producer of mycotoxins, including aflatoxin B1 (AFB1). As part of our ongoing studies to elucidate the biological functions of the A. flavus rtfA gene, we examined its role in the pathogenicity of both plant and animal model systems. rtfA encodes a putative RNA polymerase II (Pol II) transcription elongation factor previously characterized in Saccharomyces cerevisiae, Aspergillus nidulans, and Aspergillus fumigatus, where it was shown to regulate several important cellular processes, including morphogenesis and secondary metabolism. In addition, an initial study in A. flavus indicated that rtfA also influences development and production of AFB1; however, its effect on virulence is unknown. The current study reveals that the rtfA gene is indispensable for normal pathogenicity in plants when using peanut seed as an infection model, as well as in animals, as shown in the Galleria mellonella infection model. Interestingly, rtfA positively regulates several processes known to be necessary for successful fungal invasion and colonization of host tissue, such as adhesion to surfaces, protease and lipase activity, cell wall composition and integrity, and tolerance to oxidative stress. In addition, metabolomic analysis revealed that A. flavus rtfA affects the production of several secondary metabolites, including AFB1, aflatrem, leporins, aspirochlorine, ditryptophenaline, and aflavinines, supporting a role of rtfA as a global regulator of secondary metabolism. Heterologous complementation of an A. flavus rtfA deletion strain with rtfA homologs from A. nidulans or S. cerevisiae fully rescued the wild-type phenotype, indicating that these rtfA homologs are functionally conserved among these three species.IMPORTANCE In this study, the epigenetic global regulator rtfA, which encodes a putative RNA-Pol II transcription elongation factor-like protein, was characterized in the mycotoxigenic and opportunistic pathogen A. flavus Specifically, its involvement in A. flavus pathogenesis in plant and animal models was studied. Here, we show that rtfA positively regulates A. flavus virulence in both models. Furthermore, rtfA-dependent effects on factors necessary for successful invasion and colonization of host tissue by A. flavus were also assessed. Our study indicates that rtfA plays a role in A. flavus adherence to surfaces, hydrolytic activity, normal cell wall formation, and response to oxidative stress. This study also revealed a profound effect of rtfA on the metabolome of A. flavus, including the production of potent mycotoxins.
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Yang M, Lu L, Li S, Zhang J, Li Z, Wu S, Guo Q, Liu H, Wang C. Transcriptomic Insights into Benzenamine Effects on the Development, Aflatoxin Biosynthesis, and Virulence of Aspergillus flavus. Toxins (Basel) 2019; 11:E70. [PMID: 30691218 PMCID: PMC6410012 DOI: 10.3390/toxins11020070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/24/2019] [Accepted: 01/25/2019] [Indexed: 01/02/2023] Open
Abstract
Aspergillus flavus is a soilborne pathogenic fungus that poses a serious public health threat due to it contamination of food with carcinogenic aflatoxins. Our previous studies have demonstrated that benzenamine displayed strong inhibitory effects on the mycelial growth of A. flavus. In this study, we systematically investigated the inhibitory effects of benzenamine on the development, aflatoxin biosynthesis, and virulence in A. flavus, as well as the underlying mechanism. The results indicated that benzenamine exhibited great capacity to combat A. flavus at a concentration of 100 µL/L, leading to significantly decreased aflatoxin accumulation and colonization capacity in maize. The transcriptional profile revealed that 3589 genes show altered mRNA levels in the A. flavus after treatment with benzenamine, including 1890 down-regulated and 1699 up-regulated genes. Most of the differentially expressed genes participated in the biosynthesis and metabolism of amino acid, purine metabolism, and protein processing in endoplasmic reticulum. Additionally, the results brought us to a suggestion that benzenamine affects the development, aflatoxin biosynthesis, and pathogenicity of A. flavus via down-regulating related genes by depressing the expression of the global regulatory factor leaA. Overall, this study indicates that benzenamine have tremendous potential to act as a fumigant against pathogenic A. flavus. Furthermore, this work offers valuable information regarding the underlying antifungal mechanism of benzenamine against A. flavus at the level of transcription, and these potential targets may be conducive in developing new strategies for preventing aflatoxin contamination.
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Affiliation(s)
- Mingguan Yang
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Laifeng Lu
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Shuhua Li
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Jing Zhang
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Zhenjing Li
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Shufen Wu
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Qingbin Guo
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Huanhuan Liu
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
| | - Changlu Wang
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Food Nutrition and Safety, Ministry of Education, College of Food Engineering and Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, China.
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Chaves-Lopez C, Nguyen HN, Oliveira RC, Nadres ET, Paparella A, Rodrigues DF. A morphological, enzymatic and metabolic approach to elucidate apoptotic-like cell death in fungi exposed to h- and α-molybdenum trioxide nanoparticles. NANOSCALE 2018; 10:20702-20716. [PMID: 30398279 DOI: 10.1039/c8nr06470a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The present study compares for the first time the effects of h-MoO3 and α-MoO3 against two fungal strains: Aspergillus niger and Aspergillus flavus. The h-MoO3 nanoparticles were more toxic to both fungi than α-MoO3. The toxic effects of h-MoO3 were more pronounced toward A. flavus, which presented a growth inhibition of 67.4% at 200 mg L-1. The presence of the nanoparticles affected drastically the hyphae morphology by triggering nuclear condensation and compromising the hyphae membrane. Further analysis of the volatile organic compounds (VOCs) produced by both fungi in the presence of the nanomaterials indicated important metabolic changes related to programmed cell death. These nanomaterials induced the production of specific antifungal VOCs, such as β-Elemene and t-Cadinol, by the fungi. The production of essential enzymes involved in fungal metabolism, such as acid phosphatase, naphthol-As-BI-phosphohydrolase, β-galactosidase, β-glucosidase and N-acetyl-β-glucosaminidase, reduced significantly in the presence of the nanomaterials. The changes in enzymatic production and VOCs corroborate the fact that these nanoparticles, especially h-MoO3, exert changes in the fungal metabolism, triggering apoptotic-like cell death responses in these fungi.
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Affiliation(s)
- Clemencia Chaves-Lopez
- Facoltà di Bioscenze e Tecnologie Agroalimentari ed ambientali, Università degli Studi di Teramo, Via R. Balzarini 1, 64100 Teramo, Italy
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Barbosa CS, Fonseca RRD, Batista TM, Barreto MA, Argolo CS, Carvalho MRD, Amaral DOJD, Silva EMDA, Arévalo-Gardini E, Hidalgo KS, Franco GR, Pirovani CP, Micheli F, Gramacho KP. Genome sequence and effectorome of Moniliophthora perniciosa and Moniliophthora roreri subpopulations. BMC Genomics 2018; 19:509. [PMID: 29969982 PMCID: PMC6029071 DOI: 10.1186/s12864-018-4875-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/18/2018] [Indexed: 12/03/2022] Open
Abstract
Background The hemibiotrophic pathogens Moniliophthora perniciosa (witches’ broom disease) and Moniliophthora roreri (frosty pod rot disease) are among the most important pathogens of cacao. Moniliophthora perniciosa has a broad host range and infects a variety of meristematic tissues in cacao plants, whereas M. roreri infects only pods of Theobroma and Herrania genera. Comparative pathogenomics of these fungi is essential to understand Moniliophthora infection strategies, therefore the detection and in silico functional characterization of effector candidates are important steps to gain insight on their pathogenicity. Results Candidate secreted effector proteins repertoire were predicted using the genomes of five representative isolates of M. perniciosa subpopulations (three from cacao and two from solanaceous hosts), and one representative isolate of M. roreri from Peru. Many putative effectors candidates were identified in M. perniciosa: 157 and 134 in cacao isolates from Bahia, Brazil; 109 in cacao isolate from Ecuador, 92 and 80 in wild solanaceous isolates from Minas Gerais (Lobeira) and Bahia (Caiçara), Brazil; respectively. Moniliophthora roreri showed the highest number of effector candidates, a total of 243. A set of eight core effectors were shared among all Moniliophthora isolates, while others were shared either between the wild solanaceous isolates or among cacao isolates. Mostly, candidate effectors of M. perniciosa were shared among the isolates, whereas in M. roreri nearly 50% were exclusive to the specie. In addition, a large number of cell wall-degrading enzymes characteristic of hemibiotrophic fungi were found. From these, we highlighted the proteins involved in cell wall modification, an enzymatic arsenal that allows the plant pathogens to inhabit environments with oxidative stress, which promotes degradation of plant compounds and facilitates infection. Conclusions The present work reports six genomes and provides a database of the putative effectorome of Moniliophthora, a first step towards the understanding of the functional basis of fungal pathogenicity. Electronic supplementary material The online version of this article (10.1186/s12864-018-4875-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Ceslaine Santos Barbosa
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil.,Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC), Centro de Pesquisas do Cacau (CEPEC), Seção de Fitossanidade (SEFIT), Laboratório de Fitopatologia Molecular (FITOMOL), km 22 Rod. Ilhéus Itabuna, Ilhéus, 45600-970, Bahia, Brazil
| | - Rute R da Fonseca
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto, Portugal
| | - Thiago Mafra Batista
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais/Belo Horizonte, Minas Gerais, Brazil
| | - Mariana Araújo Barreto
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil.,Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC), Centro de Pesquisas do Cacau (CEPEC), Seção de Fitossanidade (SEFIT), Laboratório de Fitopatologia Molecular (FITOMOL), km 22 Rod. Ilhéus Itabuna, Ilhéus, 45600-970, Bahia, Brazil
| | - Caio Suzart Argolo
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil
| | - Mariana Rocha de Carvalho
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil.,Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC), Centro de Pesquisas do Cacau (CEPEC), Seção de Fitossanidade (SEFIT), Laboratório de Fitopatologia Molecular (FITOMOL), km 22 Rod. Ilhéus Itabuna, Ilhéus, 45600-970, Bahia, Brazil
| | - Daniel Oliveira Jordão do Amaral
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil
| | - Edson Mário de Andrade Silva
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil
| | | | - Karina Solis Hidalgo
- Instituto Nacional de Investigaciones Agropecuarias - INIAP, Departamento de Protección Vegetal, Quito, Ecuador
| | - Glória Regina Franco
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais/Belo Horizonte, Minas Gerais, Brazil
| | - Carlos Priminho Pirovani
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil
| | - Fabienne Micheli
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil.,CIRAD, UMR AGAP, F-34398, Montpellier, France
| | - Karina Peres Gramacho
- Departamento de Ciências Biológicas (DCB), Centro de Biotecnologia e Genética (CBG), Universidade Estadual de Santa Cruz (UESC), Rodovia Ilhéus-Itabuna, km 16, Ilhéus, 45662-900, Bahia, Brazil. .,Comissão Executiva do Plano da Lavoura Cacaueira (CEPLAC), Centro de Pesquisas do Cacau (CEPEC), Seção de Fitossanidade (SEFIT), Laboratório de Fitopatologia Molecular (FITOMOL), km 22 Rod. Ilhéus Itabuna, Ilhéus, 45600-970, Bahia, Brazil.
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27
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Camiletti BX, Moral J, Asensio CM, Torrico AK, Lucini EI, Giménez-Pecci MDLP, Michailides TJ. Characterization of Argentinian Endemic Aspergillus flavus Isolates and Their Potential Use as Biocontrol Agents for Mycotoxins in Maize. PHYTOPATHOLOGY 2018; 108:818-828. [PMID: 29384448 DOI: 10.1094/phyto-07-17-0255-r] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Maize (Zea mays L.) is a highly valuable crop in Argentina, frequently contaminated with the mycotoxins produced by Aspergillus flavus. Biocontrol products formulated with atoxigenic (nontoxic) strains of this fungal species are well known as an effective method to reduce this contamination. In the present study, 83 A. flavus isolates from two maize regions of Argentina were characterized and evaluated for their ability to produce or lack of producing mycotoxins in order to select atoxigenic strains to be used as potential biocontrol agents (BCA). All of the isolates were tested for aflatoxin and cyclopiazonic acid (CPA) production in maize kernels and a liquid culture medium. Genetic diversity of the nonaflatoxigenic isolates was evaluated by analysis of vegetative compatibility groups (VCG) and confirmation of deletions in the aflatoxin biosynthesis cluster. Eight atoxigenic isolates were compared for their ability to reduce aflatoxin and CPA contamination in maize kernels in coinoculation tests. The A. flavus population was composed of 32% aflatoxin and CPA producers and 52% CPA producers, and 16% was determined as atoxigenic. All of the aflatoxin producer isolates also produced CPA. Aflatoxin and CPA production was significantly higher in maize kernels than in liquid medium. The 57 nonaflatoxigenic strains formed six VCG, with AM1 and AM5 being the dominant groups, with a frequency of 58 and 35%, respectively. In coinoculation experiments, all of the atoxigenic strains reduced aflatoxin from 54 to 83% and CPA from 60 to 97%. Members of group AM1 showed a greater aflatoxin reduction than members of AM5 (72 versus 66%) but no differences were detected in CPA production. Here, we described for the first time atoxigenic isolates of A. flavus that show promise to be used as BCA in maize crops in Argentina. This innovating biological control approach should be considered, developed further, and used by the maize industry to preserve the quality properties and food safety of maize kernels in Argentina.
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Affiliation(s)
- Boris X Camiletti
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Juan Moral
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Claudia M Asensio
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Ada Karina Torrico
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Enrique I Lucini
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - María de la Paz Giménez-Pecci
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
| | - Themis J Michailides
- First author: Microbiología Agrícola, Facultad de Ciencias Agropecuarias, Universidad Nacional de Córdoba (FCA-UNC), CONICET, 5009 Córdoba, Argentina and Instituto de Patología Vegetal, Centro de Investigaciones Agropecuarias, Instituto Nacional de Tecnología Agropecuaria (IPAVE-INTA), 5020 Córdoba, Argentina; second author: Departamento de Agronomía, University of Córdoba, Campus de Rabanales, Edif. C4, 14071 Cordoba, Spain and Kearney Agricultural Research and Extension Center, University of California, Davis (UC-Davis) 93648; third author: Química Biológica, FCA-UNC, CONICET; fourth and sixth authors: IPAVE-INTA; fifth author: Microbiología Agrícola, FCA-UNC; and seventh author: Kearney Agricultural Research and Extension Center, UC-Davis
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28
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Fasoyin OE, Wang B, Qiu M, Han X, Chung KR, Wang S. Carbon catabolite repression gene creA regulates morphology, aflatoxin biosynthesis and virulence in Aspergillus flavus. Fungal Genet Biol 2018; 115:41-51. [DOI: 10.1016/j.fgb.2018.04.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 04/08/2018] [Accepted: 04/11/2018] [Indexed: 11/24/2022]
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29
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Jariwal R, Heidari A, Sandhu A, Patel J, Shoaepour K, Natarajan P, Cobos E. Granulomatous Invasive Aspergillus flavus Infection Involving the Nasal Sinuses and Brain. J Investig Med High Impact Case Rep 2018; 6:2324709618770473. [PMID: 29761110 PMCID: PMC5946347 DOI: 10.1177/2324709618770473] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/09/2018] [Accepted: 03/18/2018] [Indexed: 12/13/2022] Open
Abstract
Invasive fungal infections are commonly associated with some form of immunosuppression. On the nasal epithelial surface, Aspergillus flavus, under favorable conditions, can aggressively breach multiple cell lines invading the local tissues. We present the case of a 35-year-old woman with granulomatous invasive Aspergillus flavus infection involving the nasal sinuses and the brain. Antifungal agents administered in the previous episodes contained the infection; however, the infected site evolved over time surrounded with calcified tissues in the left maxillary sinus. The current infection involved the other side of the maxillary sinus and extended to the orbital cavity eroding the parts of the skull and retro-orbital structures and was treated with a long course of isavuconazole therapy.
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30
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Fountain JC, Koh J, Yang L, Pandey MK, Nayak SN, Bajaj P, Zhuang WJ, Chen ZY, Kemerait RC, Lee RD, Chen S, Varshney RK, Guo B. Proteome analysis of Aspergillus flavus isolate-specific responses to oxidative stress in relationship to aflatoxin production capability. Sci Rep 2018; 8:3430. [PMID: 29467403 PMCID: PMC5821837 DOI: 10.1038/s41598-018-21653-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/03/2018] [Indexed: 12/24/2022] Open
Abstract
Aspergillus flavus is an opportunistic pathogen of plants such as maize and peanut under conducive conditions such as drought stress resulting in significant aflatoxin production. Drought-associated oxidative stress also exacerbates aflatoxin production by A. flavus. The objectives of this study were to use proteomics to provide insights into the pathogen responses to H2O2-derived oxidative stress, and to identify potential biomarkers and targets for host resistance breeding. Three isolates, AF13, NRRL3357, and K54A with high, moderate, and no aflatoxin production, were cultured in medium supplemented with varying levels of H2O2, and examined using an iTRAQ (Isobaric Tags for Relative and Absolute Quantification) approach. Overall, 1,173 proteins were identified and 220 were differentially expressed (DEPs). Observed DEPs encompassed metabolic pathways including antioxidants, carbohydrates, pathogenicity, and secondary metabolism. Increased lytic enzyme, secondary metabolite, and developmental pathway expression in AF13 was correlated with oxidative stress tolerance, likely assisting in plant infection and microbial competition. Elevated expression of energy and cellular component production in NRRL3357 and K54A implies a focus on oxidative damage remediation. These trends explain isolate-to-isolate variation in oxidative stress tolerance and provide insights into mechanisms relevant to host plant interactions under drought stress allowing for more targeted efforts in host resistance research.
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Affiliation(s)
- Jake C Fountain
- Department of Plant Pathology, University of Georgia, Tifton, GA, USA.,USDA-ARS Crop Protection and Management Research Unit, Tifton, GA, USA.,Center of Excellence in Genomics & Systems Biology, International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India
| | - Jin Koh
- Department of Biology, Genetics Institute, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, USA
| | - Liming Yang
- Department of Plant Pathology, University of Georgia, Tifton, GA, USA.,USDA-ARS Crop Protection and Management Research Unit, Tifton, GA, USA.,College of Biology and Environmental Science, Nanjing Forestry University, Nanjing, China
| | - Manish K Pandey
- Center of Excellence in Genomics & Systems Biology, International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India
| | - Spurthi N Nayak
- Center of Excellence in Genomics & Systems Biology, International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India
| | - Prasad Bajaj
- Center of Excellence in Genomics & Systems Biology, International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India
| | - Wei-Jian Zhuang
- College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China
| | - Zhi-Yuan Chen
- Department of Plant Pathology and Crop Physiology, Louisiana State University, Baton Rouge, LA, USA
| | - Robert C Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, GA, USA
| | - R Dewey Lee
- Department of Crop and Soil Sciences, University of Georgia, Tifton, GA, USA
| | - Sixue Chen
- Department of Biology, Genetics Institute, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, FL, USA
| | - Rajeev K Varshney
- Center of Excellence in Genomics & Systems Biology, International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana, India
| | - Baozhu Guo
- USDA-ARS Crop Protection and Management Research Unit, Tifton, GA, USA.
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31
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Olonisakin OO, Jeff-Agboola YA, Ogidi CO, Akinyele BJ. Isolation of Antifungal Lactic Acid Bacteria (LAB) from "Kunu" against Toxigenic Aspergillus flavus. Prev Nutr Food Sci 2017; 22:138-143. [PMID: 28702431 PMCID: PMC5503423 DOI: 10.3746/pnf.2017.22.2.138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/17/2017] [Indexed: 11/30/2022] Open
Abstract
The antifungal activity of isolated lactic acid bacteria (LAB) from a locally fermented cereal, “Kunu”, was tested against toxigenic Aspergillus flavus. The liquid refreshment, “Kunu”, was prepared under hygienic condition using millet, sorghum, and the combination of the two grains. The antifungal potential of isolated LAB against toxigenic A. flavus was carried out using both in vitro and in vivo antifungal assays. The LAB count from prepared “Kunu” ranged from 2.80 ×104 CFU/mL to 4.10×104 CFU/mL and Lactobacillus plantarum, Lactobacillus delbrueckii, Lactobacillus fermentum, Pediococcus acidilactici, and Leuconostoc mesenteroides were the isolated bacteria. Inhibitory zones exhibited by LAB against toxigenic A. flavus ranged from 5.0 mm to 20.0 mm. The albino mice infected with toxigenic A. flavus showed sluggishness, decrease in body weight, distortion of hair, and presence of blood in their stool, while those treated with LAB after infection were recovered and active like those in control groups. Except for the white blood cell that was increased in the infected mice as 6.73 mm3, the packed cell volume, hemoglobin, and red blood cell in infected animals were significantly reduced (P<0.05) to 29.28%, 10.06%, and 4.28%, respectively, when compared to the treated mice with LAB and control groups. The antifungal activity of LAB against toxigenic A. flavus can be attributed to the antimicrobial metabolites. These metabolites can be extracted and used as biopreservatives in food products to substitute the use of chemical preservatives that is not appealing to consumers due to several side effects.
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Affiliation(s)
| | | | - Clement Olusola Ogidi
- Department of Microbiology, The Federal University of Technology, Akure, Ondo State 340001, Nigeria
| | - Bamidele Juliet Akinyele
- Department of Microbiology, The Federal University of Technology, Akure, Ondo State 340001, Nigeria
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32
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Paulussen C, Hallsworth JE, Álvarez‐Pérez S, Nierman WC, Hamill PG, Blain D, Rediers H, Lievens B. Ecology of aspergillosis: insights into the pathogenic potency of Aspergillus fumigatus and some other Aspergillus species. Microb Biotechnol 2017; 10:296-322. [PMID: 27273822 PMCID: PMC5328810 DOI: 10.1111/1751-7915.12367] [Citation(s) in RCA: 179] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 04/08/2016] [Accepted: 04/18/2016] [Indexed: 01/26/2023] Open
Abstract
Fungi of the genus Aspergillus are widespread in the environment. Some Aspergillus species, most commonly Aspergillus fumigatus, may lead to a variety of allergic reactions and life-threatening systemic infections in humans. Invasive aspergillosis occurs primarily in patients with severe immunodeficiency, and has dramatically increased in recent years. There are several factors at play that contribute to aspergillosis, including both fungus and host-related factors such as strain virulence and host pulmonary structure/immune status, respectively. The environmental tenacity of Aspergilllus, its dominance in diverse microbial communities/habitats, and its ability to navigate the ecophysiological and biophysical challenges of host infection are attributable, in large part, to a robust stress-tolerance biology and exceptional capacity to generate cell-available energy. Aspects of its stress metabolism, ecology, interactions with diverse animal hosts, clinical presentations and treatment regimens have been well-studied over the past years. Here, we synthesize these findings in relation to the way in which some Aspergillus species have become successful opportunistic pathogens of human- and other animal hosts. We focus on the biophysical capabilities of Aspergillus pathogens, key aspects of their ecophysiology and the flexibility to undergo a sexual cycle or form cryptic species. Additionally, recent advances in diagnosis of the disease are discussed as well as implications in relation to questions that have yet to be resolved.
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Affiliation(s)
- Caroline Paulussen
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Sergio Álvarez‐Pérez
- Faculty of Veterinary MedicineDepartment of Animal HealthUniversidad Complutense de MadridMadridE‐28040Spain
| | | | - Philip G. Hamill
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - David Blain
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen's University BelfastBelfastBT9 7BLUK
| | - Hans Rediers
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
| | - Bart Lievens
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM)Department of Microbial and Molecular Systems (M2S)KU LeuvenCampus De NayerSint‐Katelijne‐WaverB‐2860Belgium
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33
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Xu L, Eisa Ahmed MF, Sangare L, Zhao Y, Selvaraj JN, Xing F, Wang Y, Yang H, Liu Y. Novel Aflatoxin-Degrading Enzyme from Bacillus shackletonii L7. Toxins (Basel) 2017; 9:E36. [PMID: 28098812 PMCID: PMC5308268 DOI: 10.3390/toxins9010036] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 11/25/2022] Open
Abstract
Food and feed contamination by aflatoxin (AF)B₁ has adverse economic and health consequences. AFB₁ degradation by microorganisms or microbial enzymes provides a promising preventive measure. To this end, the present study tested 43 bacterial isolates collected from maize, rice, and soil samples for AFB₁-reducing activity. The higher activity was detected in isolate L7, which was identified as Bacillus shackletonii. L7 reduced AFB₁, AFB₂, and AFM₁ levels by 92.1%, 84.1%, and 90.4%, respectively, after 72 h at 37 °C. The L7 culture supernatant degraded more AFB₁ than viable cells and cell extracts; and the degradation activity was reduced from 77.9% to 15.3% in the presence of proteinase K and sodium dodecyl sulphate. A thermostable enzyme purified from the boiled supernatant was designated as Bacillus aflatoxin-degrading enzyme (BADE). An overall 9.55-fold purification of BADE with a recovery of 39.92% and an activity of 3.85 × 10³ U·mg-1 was obtained using chromatography on DEAE-Sepharose. BADE had an estimated molecular mass of 22 kDa and exhibited the highest activity at 70 °C and pH 8.0, which was enhanced by Cu2+ and inhibited by Zn2+, Mn2+, Mg2+, and Li⁺. BADE is the major protein involved in AFB₁ detoxification. This is the first report of a BADE isolated from B. shackletonii, which has potential applications in the detoxification of aflatoxins during food and feed processing.
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Affiliation(s)
- Liang Xu
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Mohamed Farah Eisa Ahmed
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Lancine Sangare
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Yueju Zhao
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Jonathan Nimal Selvaraj
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Yan Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
| | - Hongping Yang
- Shenyang Institute of Engineering, No.18 Puchang Road, Shenbei New District, Shenyang 110136, China.
| | - Yang Liu
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, 1 Nongda South Road, Xibeiwang Town, Haidian District, Beijing 100193, China.
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Baquião AC, Rodriges AG, Lopes EL, Tralamazza SM, Zorzete P, Correa B. Expression of Genes by Aflatoxigenic and Nonaflatoxigenic Strains of Aspergillus flavus Isolated from Brazil Nuts. Foodborne Pathog Dis 2016; 13:434-40. [PMID: 27224419 DOI: 10.1089/fpd.2015.2111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The aims of the present study were to monitor the production of aflatoxin B1 (AFB1) and mycelial growth, and to evaluate the expression of genes directly and indirectly involved in the biosynthesis of aflatoxins by Aspergillus flavus isolated from Brazil nuts. Six previously identified A. flavus strains were grown on coconut agar at 25°C for up to 10 days. Mycotoxins were separated by high-performance liquid chromatography and fungal growth was measured daily using the diametric mycelial growth rate. Transcriptional analysis was performed by real-time polymerase chain reaction (PCR) after 2 and 7 d of incubation using specific primers (aflR, aflD, aflP, lipase, metalloprotease, and LaeA). Three (50%) of the six A. flavus isolates produced AFB1 (ICB-1, ICB-12, and ICB-54) and three (50%) were not aflatoxigenic (ICB-141, ICB-161, and ICB-198). Aflatoxin production was observed from d 2 of incubation (1.5 ng/g for ICB-54) and increased gradually with time of incubation until d 10 (15,803.6 ng/g for ICB-54). Almost all A. flavus isolates exhibited a similar gene expression pattern after 2 d of incubation (p > 0.10). After 7 d of incubation, the LaeA (p < 0.05) and metalloprotease (p < 0.05) genes were the most expressed by nonaflatoxigenic strains, whereas aflatoxigenic isolates exhibited higher expression of the aflR (p < 0.05) and aflD genes (p < 0.05). Our results suggest that the expression of aflR and aflD is correlated with aflatoxin production in A. flavus and that overexpression of aflR could affect the transcriptional and aflatoxigenic pattern (ICB-54). Elucidation of the molecular mechanisms that regulate the secondary metabolism of toxigenic fungi may permit the rational silencing of the genes involved and consequently the programmed inhibition of aflatoxin production. Knowledge of the conditions, under which aflatoxin genes are expressed, should contribute to the development of innovative and more cost-effective strategies to reduce and prevent aflatoxin contamination in Brazil nuts.
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Affiliation(s)
- Arianne Costa Baquião
- 1 Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil
| | - Aline Guedes Rodriges
- 1 Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil
| | - Evandro Luiz Lopes
- 2 Escola Paulista de Política, Economia e Negócios, Universidade Federal de São Paulo , São Paulo, Brazil
| | - Sabina Moser Tralamazza
- 1 Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil
| | - Patricia Zorzete
- 1 Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil
| | - Benedito Correa
- 1 Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo , São Paulo, Brazil
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Zhuang Z, Lohmar JM, Satterlee T, Cary JW, Calvo AM. The Master Transcription Factor mtfA Governs Aflatoxin Production, Morphological Development and Pathogenicity in the Fungus Aspergillus flavus. Toxins (Basel) 2016; 8:toxins8010029. [PMID: 26805883 PMCID: PMC4728551 DOI: 10.3390/toxins8010029] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 12/23/2015] [Accepted: 01/06/2016] [Indexed: 11/30/2022] Open
Abstract
Aspergillus flavus produces a variety of toxic secondary metabolites; among them, the aflatoxins (AFs) are the most well known. These compounds are highly mutagenic and carcinogenic, particularly AFB1. A. flavus is capable of colonizing a number of economically-important crops, such as corn, cotton, peanut and tree nuts, and contaminating them with AFs. Molecular genetic studies in A. flavus could identify novel gene targets for use in strategies to reduce AF contamination and its adverse impact on food and feed supplies worldwide. In the current study, we investigated the role of the master transcription factor gene mtfA in A. flavus. Our results revealed that forced overexpression of mtfA results in a drastic decrease or elimination of several secondary metabolites, among them AFB1. The reduction in AFB1 was accompanied by a decrease in aflR expression. Furthermore, mtfA also regulates development; conidiation was influenced differently by this gene depending on the type of colonized substrate. In addition to its effect on conidiation, mtfA is necessary for the normal maturation of sclerotia. Importantly, mtfA positively affects the pathogenicity of A. flavus when colonizing peanut seeds. AF production in colonized seeds was decreased in the deletion mtfA strain and particularly in the overexpression strain, where only trace amounts were detected. Interestingly, a more rapid colonization of the seed tissue occurred when mtfA was overexpressed, coinciding with an increase in lipase activity and faster maceration of the oily part of the seed.
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Affiliation(s)
- Zhenhong Zhuang
- Department of Biological Sciences, Northern Illinois University, 155 Castle Dr., Dekalb, IL 60115, USA.
| | - Jessica M Lohmar
- Department of Biological Sciences, Northern Illinois University, 155 Castle Dr., Dekalb, IL 60115, USA.
| | - Timothy Satterlee
- Department of Biological Sciences, Northern Illinois University, 155 Castle Dr., Dekalb, IL 60115, USA.
| | - Jeffrey W Cary
- Food and Feed Safety Research Unit, USDA/ARS, Southern Regional Research Center, New Orleans, LA 70124, USA.
| | - Ana M Calvo
- Department of Biological Sciences, Northern Illinois University, 155 Castle Dr., Dekalb, IL 60115, USA.
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Zorzete P, Oliveira RC, Corrêa B. Effects of Conventional and High-Oleic Peanut Medium on Extracellular Enzyme Production and Mycelial Growth of Aspergillus Flavus. J Food Saf 2016. [DOI: 10.1111/jfs.12262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Patricia Zorzete
- Departamento de Microbiologia; Instituto Ciências Biomédicas, Universidade de São Paulo; Av. Prof. Lineu Prestes, 1374 CEP 05508-000 São Paulo SP Brazil
| | - Rodrigo Cardoso Oliveira
- Departamento de Microbiologia; Instituto Ciências Biomédicas, Universidade de São Paulo; Av. Prof. Lineu Prestes, 1374 CEP 05508-000 São Paulo SP Brazil
| | - Benedito Corrêa
- Departamento de Microbiologia; Instituto Ciências Biomédicas, Universidade de São Paulo; Av. Prof. Lineu Prestes, 1374 CEP 05508-000 São Paulo SP Brazil
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Abbas HK, Zablotowicz RM, Shier WT, Johnson BJ, Phillips NA, Weaver MA, Abel CA, Bruns HA. Aflatoxin and Fumonisin in Corn (Zea mays) Infected by Common Smut Ustilago maydis. PLANT DISEASE 2015; 99:1236-1240. [PMID: 30695921 DOI: 10.1094/pdis-03-14-0234-re] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Corn infected with Ustilago maydis (common smut) produces galls that are valued as a delicacy in some cultures. During a 4-year period, aflatoxin levels in asymptomatic kernels of smutted ears were, on average, 45-fold higher than in kernels harvested from smut-free control ears and 99-fold higher than in smut galls. Aflatoxin levels in smut galls were lower than in kernels of smut-free control corn in all years combined. Fumonisin levels in asymptomatic kernels harvested from smutted ears were 5.2-fold higher than in kernels from smut-free control ears and 4.0-fold higher than in smut galls. Fumonisin levels in smut galls were not significantly different than in kernels of smut-free control corn. These studies indicate that, although corn smut was relatively free of the mycotoxins studied, the asymptomatic kernels of those ears contained mycotoxins at levels much higher than usually considered safe for direct human consumption.
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Affiliation(s)
| | - Robert M Zablotowicz
- Crop Production Systems Research Unit, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), Stoneville, MS 38776
| | - W Thomas Shier
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis 55455
| | | | | | | | - Craig A Abel
- Corn Insect and Crop Genetics Research Unit, USDA-ARS, Iowa State University, Ames 50010
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Extracellular Xylanolytic and Pectinolytic Hydrolase Production by Aspergillus flavus Isolates Contributes to Crop Invasion. Toxins (Basel) 2015; 7:3257-66. [PMID: 26295409 PMCID: PMC4549749 DOI: 10.3390/toxins7083257] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 07/30/2015] [Accepted: 08/03/2015] [Indexed: 11/19/2022] Open
Abstract
Several atoxigenic Aspergillus flavus isolates, including some being used as biocontrol agents, and one toxigenic isolate were surveyed for the ability to produce extracellular xylanolytic and pectinolytic hydrolases. All of the tested isolates displayed good production of endoxylanases when grown on a medium utilizing larch xylan as a sole carbon substrate. Four of the tested isolates produced reasonably high levels of esterase activity, while the atoxigenic biocontrol agent NRRL 21882 isolate esterase level was significantly lower than the others. Atoxigenic A. flavus isolates 19, 22, K49, AF36 (the latter two are biocontrol agents) and toxigenic AF13 produced copious levels of pectinolytic activity when grown on a pectin medium. The pectinolytic activity levels of the atoxigenic A. flavus 17 and NRRL 21882 isolates were significantly lower than the other tested isolates. In addition, A. flavus isolates that displayed high levels of pectinolytic activity in the plate assay produced high levels of endopolygalacturonase (pectinase) P2c, as ascertained by isoelectric focusing electrophoresis. Isolate NRRL 21882 displayed low levels of both pectinase P2c and pectin methyl esterase. A. flavus appears capable of producing these hydrolytic enzymes irrespective of aflatoxin production. This ability of atoxigenic isolates to produce xylanolytic and pectinolytic hydrolases mimics that of toxigenic isolates and, therefore, contributes to the ability of atoxigenic isolates to occupy the same niche as A. flavus toxigenic isolates.
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39
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Molecular and functional diversity of yeast and fungal lipases: Their role in biotechnology and cellular physiology. Prog Lipid Res 2015; 57:40-54. [DOI: 10.1016/j.plipres.2014.12.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/30/2014] [Accepted: 12/18/2014] [Indexed: 01/12/2023]
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40
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Zhang F, Zhong H, Han X, Guo Z, Yang W, Liu Y, Yang K, Zhuang Z, Wang S. Proteomic profile of Aspergillus flavus in response to water activity. Fungal Biol 2014; 119:114-24. [PMID: 25749363 DOI: 10.1016/j.funbio.2014.11.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 11/21/2014] [Accepted: 11/24/2014] [Indexed: 12/12/2022]
Abstract
Aspergillus flavus, a common contaminant of crops and stored grains, can produce aflatoxins that are harmful to humans and other animals. Water activity (aw) is one of the key factors influencing both fungal growth and mycotoxin production. In this study, we used the isobaric tagging for relative and absolute quantitation (iTRAQ) technique to investigate the effect of aw on the proteomic profile of A. flavus. A total of 3566 proteins were identified, of which 837 were differentially expressed in response to variations in aw. Among these 837 proteins, 403 were over-expressed at 0.99 aw, whereas 434 proteins were over-expressed at 0.93 aw. According to Gene Ontology (GO) analysis, the secretion of extracellular hydrolases increased as aw was raised, suggesting that extracellular hydrolases may play a critical role in induction of aflatoxin biosynthesis. On the basis of Clusters of Orthologous Groups (COG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) categorizations, we identified an exportin protein, KapK, that may down-regulate aflatoxin biosynthesis by changing the location of NirA. Finally, we considered the role of two osmotic stress-related proteins (Sln1 and Glo1) in the Hog1 pathway and investigated the expression patterns of proteins related to aflatoxin biosynthesis. The data uncovered in this study are critical for understanding the effect of water stress on toxin production and for the development of strategies to control toxin contamination of agricultural products.
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Affiliation(s)
- Feng Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Hong Zhong
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiaoyun Han
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenni Guo
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Weiqiang Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yongfeng Liu
- Shenzhen Key Laboratory of Bioenergy, BGI-Shenzhen, Shenzhen 518083, China
| | - Kunlong Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Zhenhong Zhuang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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41
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Brodhagen M, Peyron M, Miles C, Inglis DA. Biodegradable plastic agricultural mulches and key features of microbial degradation. Appl Microbiol Biotechnol 2014; 99:1039-56. [DOI: 10.1007/s00253-014-6267-5] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/27/2014] [Indexed: 10/24/2022]
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42
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Jain N, Bhargava A, Sabat D, Panwar J. Unveiling the potential of metal-tolerant fungi for efficient enzyme production. Process Biochem 2014. [DOI: 10.1016/j.procbio.2014.07.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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43
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Baidya S, Duran RM, Lohmar JM, Harris-Coward PY, Cary JW, Hong SY, Roze LV, Linz JE, Calvo AM. VeA is associated with the response to oxidative stress in the aflatoxin producer Aspergillus flavus. EUKARYOTIC CELL 2014; 13:1095-103. [PMID: 24951443 PMCID: PMC4135802 DOI: 10.1128/ec.00099-14] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/14/2014] [Indexed: 12/20/2022]
Abstract
Survival of fungal species depends on the ability of these organisms to respond to environmental stresses. Osmotic stress or high levels of reactive oxygen species (ROS) can cause stress in fungi resulting in growth inhibition. Both eukaryotic and prokaryotic cells have developed numerous mechanisms to counteract and survive the stress in the presence of ROS. In many fungi, the HOG signaling pathway is crucial for the oxidative stress response as well as for osmotic stress response. This study revealed that while the osmotic stress response is only slightly affected by the master regulator veA, this gene, also known to control morphological development and secondary metabolism in numerous fungal species, has a profound effect on the oxidative stress response in the aflatoxin-producing fungus Aspergillus flavus. We found that the expression of A. flavus homolog genes involved in the HOG signaling pathway is regulated by veA. Deletion of veA resulted in a reduction in transcription levels of oxidative stress response genes after exposure to hydrogen peroxide. Furthermore, analyses of the effect of VeA on the promoters of cat1 and trxB indicate that the presence of VeA alters DNA-protein complex formation. This is particularly notable in the cat1 promoter, where the absence of VeA results in abnormally stronger complex formation with reduced cat1 expression and more sensitivity to ROS in a veA deletion mutant, suggesting that VeA might prevent binding of negative transcription regulators to the cat1 promoter. Our study also revealed that veA positively influences the expression of the transcription factor gene atfB and that normal formation of DNA-protein complexes in the cat1 promoter is dependent on AtfB.
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Affiliation(s)
- Sachin Baidya
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - Rocio M Duran
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - Jessica M Lohmar
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
| | - Pamela Y Harris-Coward
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana, USA
| | - Jeffrey W Cary
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, Louisiana, USA
| | - Sung-Yong Hong
- Department of Food Science and Human Nutrition, Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Ludmila V Roze
- Department of Food Science and Human Nutrition, Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - John E Linz
- Department of Food Science and Human Nutrition, Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Ana M Calvo
- Department of Biological Sciences, Northern Illinois University, Dekalb, Illinois, USA
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44
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Native soil fungi associated with compostable plastics in three contrasting agricultural settings. Appl Microbiol Biotechnol 2014; 98:6467-85. [DOI: 10.1007/s00253-014-5711-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/18/2014] [Accepted: 03/19/2014] [Indexed: 12/27/2022]
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45
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Duran RM, Gregersen S, Smith TD, Bhetariya PJ, Cary JW, Harris-Coward PY, Mattison CP, Grimm C, Calvo AM. The role of Aspergillus flavus veA in the production of extracellular proteins during growth on starch substrates. Appl Microbiol Biotechnol 2014; 98:5081-94. [DOI: 10.1007/s00253-014-5598-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 02/03/2014] [Accepted: 02/04/2014] [Indexed: 01/21/2023]
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46
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Dolezal AL, Obrian GR, Nielsen DM, Woloshuk CP, Boston RS, Payne GA. Localization, morphology and transcriptional profile of Aspergillus flavus during seed colonization. MOLECULAR PLANT PATHOLOGY 2013; 14:898-909. [PMID: 23834374 PMCID: PMC6638638 DOI: 10.1111/mpp.12056] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Aspergillus flavus is an opportunistic fungal pathogen that infects maize kernels pre-harvest, creating major human health concerns and causing substantial agricultural losses. Improved control strategies are needed, yet progress is hampered by the limited understanding of the mechanisms of infection. A series of studies were designed to investigate the localization, morphology and transcriptional profile of A. flavus during internal seed colonization. Results from these studies indicate that A. flavus is capable of infecting all tissues of the immature kernel by 96 h after infection. Mycelia were observed in and around the point of inoculation in the endosperm and were found growing down to the germ. At the endosperm-germ interface, hyphae appeared to differentiate and form a biofilm-like structure that surrounded the germ. The exact nature of this structure remains unclear, but is discussed. A custom-designed A. flavus Affymetrix GeneChip® microarray was used to monitor genome-wide transcription during pathogenicity. A total of 5061 genes were designated as being differentially expressed. Genes encoding secreted enzymes, transcription factors and secondary metabolite gene clusters were up-regulated and considered to be potential effector molecules responsible for disease in the kernel. Information gained from this study will aid in the development of strategies aimed at preventing or slowing down A. flavus colonization of the maize kernel.
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Affiliation(s)
- Andrea L Dolezal
- Department of Plant Pathology, Center for Integrated Fungal Research, North Carolina State University, Raleigh, NC, 27695, USA
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47
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Gauthier GM, Keller NP. Crossover fungal pathogens: the biology and pathogenesis of fungi capable of crossing kingdoms to infect plants and humans. Fungal Genet Biol 2013; 61:146-57. [PMID: 24021881 DOI: 10.1016/j.fgb.2013.08.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 08/28/2013] [Accepted: 08/29/2013] [Indexed: 12/13/2022]
Abstract
The outbreak of fungal meningitis associated with contaminated methylprednisolone acetate has thrust the importance of fungal infections into the public consciousness. The predominant pathogen isolated from clinical specimens, Exserohilum rostratum (teleomorph: Setosphaeria rostrata), is a dematiaceous fungus that infects grasses and rarely humans. This outbreak highlights the potential for fungal pathogens to infect both plants and humans. Most crossover or trans-kingdom pathogens are soil saprophytes and include fungi in Ascomycota and Mucormycotina phyla. To establish infection, crossover fungi must overcome disparate, host-specific barriers, including protective surfaces (e.g. cuticle, skin), elevated temperature, and immune defenses. This review illuminates the underlying mechanisms used by crossover fungi to cause infection in plants and mammals, and highlights critical events that lead to human infection by these pathogens. Several genes including veA, laeA, and hapX are important in regulating biological processes in fungi important for both invasive plant and animal infections.
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48
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Nishanth Kumar S, Mohandas C, Nambisan B. Purification of an antifungal compound, cyclo(l-Pro-d-Leu) for cereals produced by Bacillus cereus subsp. thuringiensis associated with entomopathogenic nematode. Microbiol Res 2013; 168:278-88. [PMID: 23305769 DOI: 10.1016/j.micres.2012.12.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 12/15/2012] [Indexed: 11/15/2022]
Abstract
Mold spoilage is the main cause of substantial economic loss in cereals and might also cause public health problems due to the production of mycotoxins. The aim of this study was to separate and purify and to identify antifungal compounds of bacterium associated with novel entomopathogenic nematode and check the antifungal property of identified compound in particular food model systems. The antifungal compound was purified using silica gel column chromatography, TLC and HPLC and its structure was elucidated using NMR (¹H NMR, ¹³C NMR, ¹H-¹H COSY, ¹H-¹³C HMBC), HRMS and Marfey's method. Based on the spectral data, the active compounds were identified as diketopiperazine [cyclo(l-Pro-d-Leu)]. The antifungal activity of cyclo(l-Pro-d-Leu) was studied by MIC and paper disk assay against Aspergillus flavus MTCC 277 and Aspergillus niger MTCC 282 and best MIC value of 8μg/ml was recorded against A. flavus. Cyclo(l-Pro-d-Leu) strongly inhibit mycelia growth of fungus and thereby affecting aflatoxin production. To investigate the potential application of the cyclo(l-Pro-d-Leu) and to eliminate fungal spoilage in food and feed, soybean and peanut were used as models. White mycelia and dark/pale green spores of A. flavus were observed in the control soybeans after 2-day incubation. However the fungal growth was not observed in soybeans treated with cyclo(l-Pro-d-Leu). Almost the same result was observed for peanuts treated with cyclo(l-Pro-d-Leu) for A. niger. The cyclo(l-Pro-d-Leu) was nontoxic to two normal human cell lines (FS normal fibroblast and L231 lung epithelial) up to 200μg/ml. Thus the diketopiperazine derivative identified in the study may be a promising alternative to chemical preservatives as a potential biopreservative which prevent fungal growth and mycotoxin formation in food and feed.
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Affiliation(s)
- S Nishanth Kumar
- Division of Crop Protection/Division of Crop Utilization, Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram 695017, India.
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Mehl HL, Cotty PJ. Nutrient environments influence competition among Aspergillus flavus genotypes. Appl Environ Microbiol 2013; 79:1473-80. [PMID: 23263958 PMCID: PMC3591962 DOI: 10.1128/aem.02970-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/13/2012] [Indexed: 12/25/2022] Open
Abstract
The population dynamics of Aspergillus flavus, shaped in part by intraspecific competition, influence the likelihood and severity of crop aflatoxin contamination. Competition for nutrients may be one factor modulating intraspecific interactions, but the influences of specific types and concentrations of nutrients on competition between genotypes of A. flavus have not been investigated. Competition between paired A. flavus isolates on agar media was affected by varying concentrations of carbon (sucrose or asparagine) and nitrogen (nitrate or asparagine). Cocultivated isolate percentages from conidia and agar-embedded mycelia were quantified by measurements of isolate-specific single-nucleotide polymorphisms with quantitative pyrosequencing. Compositions and concentrations of nutrients influenced conidiation resulting from cocultivation, but the percentages of total conidia from each competing isolate were not predicted by sporulation of isolates grown individually. Success during sporulation did not reflect the outcomes of competition during mycelial growth, and the extents to which isolate percentages from conidia and mycelia differed varied among both isolate pairs and media. Whether varying concentrations of sucrose, nitrate, or asparagine increased, decreased, or had no influence on competitive ability was isolate dependent. Different responses of A. flavus isolates to nutrient variability suggest genotypes are adapted to different nutrient environments that have the potential to influence A. flavus population structure and the epidemiology of aflatoxin contamination.
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Affiliation(s)
- Hillary L. Mehl
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
| | - Peter J. Cotty
- School of Plant Sciences, University of Arizona, Tucson, Arizona, USA
- Agricultural Research Service, U.S. Department of Agriculture, Tucson, Arizona, USA
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Mehl HL, Jaime R, Callicott KA, Probst C, Garber NP, Ortega-Beltran A, Grubisha LC, Cotty PJ. Aspergillus flavusdiversity on crops and in the environment can be exploited to reduce aflatoxin exposure and improve health. Ann N Y Acad Sci 2012; 1273:7-17. [DOI: 10.1111/j.1749-6632.2012.06800.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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