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Garg V, Barmukh R, Chitikineni A, Roorkiwal M, Ojiewo C, Bohra A, Thudi M, Singh VK, Kudapa H, Saxena RK, Fountain J, Mir RR, Bharadwaj C, Chen X, Xin L, Pandey MK. Celebrating Professor Rajeev K. Varshney's transformative research odyssey from genomics to the field on his induction as Fellow of the Royal Society. PLANT BIOTECHNOLOGY JOURNAL 2024; 22:1504-1515. [PMID: 38206288 PMCID: PMC11123405 DOI: 10.1111/pbi.14282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/17/2023] [Accepted: 12/20/2023] [Indexed: 01/12/2024]
Abstract
Professor Rajeev K. Varshney's transformative impact on crop genomics, genetics, and agriculture is the result of his passion, dedication, and unyielding commitment to harnessing the potential of genomics to address the most pressing challenges faced by the global agricultural community. Starting from a small town in India and reaching the global stage, Professor Varshney's academic and professional trajectory has inspired many scientists active in research today. His ground-breaking work, especially his effort to list orphan tropical crops to genomic resource-rich entities, has been transformative. Beyond his scientific achievements, Professor Varshney is recognized by his colleagues as an exemplary mentor, fostering the growth of future researchers, building institutional capacity, and strengthening scientific capability. His focus on translational genomics and strengthening seed system in developing countries for the improvement of agriculture has made a tangible impact on farmers' lives. His skills have been best utilized in roles at leading research centres where he has applied his expertise to deliver a new vision for crop improvement. These efforts have now been recognized by the Royal Society with the award of the Fellowship (FRS). As we mark this significant milestone in his career, we not only celebrate Professor Varshney's accomplishments but also his wider contributions that continue to transform the agricultural landscape.
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Affiliation(s)
- Vanika Garg
- Centre for Crop & Food Innovation, WA State Agricultural Biotechnology Centre, Food Futures InstituteMurdoch UniversityMurdochWestern AustraliaAustralia
| | - Rutwik Barmukh
- Centre for Crop & Food Innovation, WA State Agricultural Biotechnology Centre, Food Futures InstituteMurdoch UniversityMurdochWestern AustraliaAustralia
| | - Annapurna Chitikineni
- Centre for Crop & Food Innovation, WA State Agricultural Biotechnology Centre, Food Futures InstituteMurdoch UniversityMurdochWestern AustraliaAustralia
| | - Manish Roorkiwal
- Khalifa Center for Genetic Engineering and BiotechnologyUnited Arab Emirates UniversityAl AinUAE
| | - Chris Ojiewo
- International Maize and Wheat Improvement Center (CIMMYT)NairobiKenya
| | - Abhishek Bohra
- Centre for Crop & Food Innovation, WA State Agricultural Biotechnology Centre, Food Futures InstituteMurdoch UniversityMurdochWestern AustraliaAustralia
| | | | - Vikas K. Singh
- International Rice Research Institute (IRRI)‐South‐Asia HubInternational Crops Research Institute for the Semi‐Arid TropicsHyderabadIndia
| | - Himabindu Kudapa
- Center of Excellence in Genomics & Systems BiologyInternational Crops Research Institute for the Semi‐Arid Tropics (ICRISAT)HyderabadIndia
| | | | - Jake Fountain
- Department of Plant PathologyUniversity of GeorgiaGriffinGeorgiaUSA
| | - Reyazul Rouf Mir
- Division of Genetics and Plant Breeding, Faculty of AgricultureSKUAST‐KashmirWaduraIndia
| | | | - Xiaoping Chen
- Crops Research InstituteGuangdong Academy of Agricultural Sciences (GDAAS)GuangzhouChina
| | | | - Manish K. Pandey
- Center of Excellence in Genomics & Systems BiologyInternational Crops Research Institute for the Semi‐Arid Tropics (ICRISAT)HyderabadIndia
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2
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Gangurde SS, Korani W, Bajaj P, Wang H, Fountain JC, Agarwal G, Pandey MK, Abbas HK, Chang PK, Holbrook CC, Kemerait RC, Varshney RK, Dutta B, Clevenger JP, Guo B. Aspergillus flavus pangenome (AflaPan) uncovers novel aflatoxin and secondary metabolite associated gene clusters. BMC PLANT BIOLOGY 2024; 24:354. [PMID: 38693487 PMCID: PMC11061970 DOI: 10.1186/s12870-024-04950-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 03/26/2024] [Indexed: 05/03/2024]
Abstract
BACKGROUND Aspergillus flavus is an important agricultural and food safety threat due to its production of carcinogenic aflatoxins. It has high level of genetic diversity that is adapted to various environments. Recently, we reported two reference genomes of A. flavus isolates, AF13 (MAT1-2 and highly aflatoxigenic isolate) and NRRL3357 (MAT1-1 and moderate aflatoxin producer). Where, an insertion of 310 kb in AF13 included an aflatoxin producing gene bZIP transcription factor, named atfC. Observations of significant genomic variants between these isolates of contrasting phenotypes prompted an investigation into variation among other agricultural isolates of A. flavus with the goal of discovering novel genes potentially associated with aflatoxin production regulation. Present study was designed with three main objectives: (1) collection of large number of A. flavus isolates from diverse sources including maize plants and field soils; (2) whole genome sequencing of collected isolates and development of a pangenome; and (3) pangenome-wide association study (Pan-GWAS) to identify novel secondary metabolite cluster genes. RESULTS Pangenome analysis of 346 A. flavus isolates identified a total of 17,855 unique orthologous gene clusters, with mere 41% (7,315) core genes and 59% (10,540) accessory genes indicating accumulation of high genomic diversity during domestication. 5,994 orthologous gene clusters in accessory genome not annotated in either the A. flavus AF13 or NRRL3357 reference genomes. Pan-genome wide association analysis of the genomic variations identified 391 significant associated pan-genes associated with aflatoxin production. Interestingly, most of the significantly associated pan-genes (94%; 369 associations) belonged to accessory genome indicating that genome expansion has resulted in the incorporation of new genes associated with aflatoxin and other secondary metabolites. CONCLUSION In summary, this study provides complete pangenome framework for the species of Aspergillus flavus along with associated genes for pathogen survival and aflatoxin production. The large accessory genome indicated large genome diversity in the species A. flavus, however AflaPan is a closed pangenome represents optimum diversity of species A. flavus. Most importantly, the newly identified aflatoxin producing gene clusters will be a new source for seeking aflatoxin mitigation strategies and needs new attention in research.
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Affiliation(s)
- Sunil S Gangurde
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA
| | - Walid Korani
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA
| | - Prasad Bajaj
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana, India
| | - Hui Wang
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Jake C Fountain
- Department of Plant Pathology, University of Georgia, Griffin, GA, 30223, USA
| | - Gaurav Agarwal
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Manish K Pandey
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana, India.
| | - Hamed K Abbas
- Biological Control of Pests Research Unit, USDA-ARS, Stoneville, MS, 38776, USA
| | - Perng-Kuang Chang
- Southern Regional Research Center, USDA-ARS, New Orleans, LA, 70124, USA
| | - C Corley Holbrook
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA
| | - Robert C Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Rajeev K Varshney
- WA State Biotechnology Centre, Centre for Crop and Food innovation, Food Futures Institute, Murdoch University, Murdoch, WA, 6150, Australia
| | - Bhabesh Dutta
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Josh P Clevenger
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, 35806, USA.
| | - Baozhu Guo
- Crop Protection and Management Research Unit, USDA-ARS, Tifton, GA, 31793, USA.
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3
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Ren Z, Dong X, Guan L, Yang L, Liu C, Cai X, Hu H, Lv Z, Liu H, Zheng L, Huang J, Wilson RA, Chen XL. Sirt5-mediated lysine desuccinylation regulates oxidative stress adaptation in Magnaporthe oryzae during host intracellular infection. THE NEW PHYTOLOGIST 2024; 242:1257-1274. [PMID: 38481385 DOI: 10.1111/nph.19683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/07/2024] [Indexed: 04/12/2024]
Abstract
Plant pathogenic fungi elaborate numerous detoxification strategies to suppress host reactive oxygen species (ROS), but their coordination is not well-understood. Here, we show that Sirt5-mediated protein desuccinylation in Magnaporthe oryzae is central to host ROS detoxification. SIRT5 encodes a desuccinylase important for virulence via adaptation to host oxidative stress. Quantitative proteomics analysis identified a large number of succinylated proteins targeted by Sirt5, most of which were mitochondrial proteins involved in oxidative phosphorylation, TCA cycle, and fatty acid oxidation. Deletion of SIRT5 resulted in hypersuccinylation of detoxification-related enzymes, and significant reduction in NADPH : NADP+ and GSH : GSSG ratios, disrupting redox balance and impeding invasive growth. Sirt5 desuccinylated thioredoxin Trx2 and glutathione peroxidase Hyr1 to activate their enzyme activity, likely by affecting proper folding. Altogether, this work demonstrates the importance of Sirt5-mediated desuccinylation in controlling fungal process required for detoxifying host ROS during M. oryzae infection.
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Affiliation(s)
- Zhiyong Ren
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiang Dong
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lun Guan
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lei Yang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Caiyun Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xuan Cai
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong Hu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ziwei Lv
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Liu
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lu Zheng
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Junbin Huang
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Richard A Wilson
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, NE, 68583, USA
| | - Xiao-Lin Chen
- State Key Laboratory of Agricultural Microbiology and Provincial Key Laboratory of Plant Pathology of Hubei Province, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu, 611130, China
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Castano-Duque L, Winzeler E, Blackstock JM, Liu C, Vergopolan N, Focker M, Barnett K, Owens PR, van der Fels-Klerx HJ, Vaughan MM, Rajasekaran K. Dynamic geospatial modeling of mycotoxin contamination of corn in Illinois: unveiling critical factors and predictive insights with machine learning. Front Microbiol 2023; 14:1283127. [PMID: 38029202 PMCID: PMC10646420 DOI: 10.3389/fmicb.2023.1283127] [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: 08/25/2023] [Accepted: 09/26/2023] [Indexed: 12/01/2023] Open
Abstract
Mycotoxin contamination of corn is a pervasive problem that negatively impacts human and animal health and causes economic losses to the agricultural industry worldwide. Historical aflatoxin (AFL) and fumonisin (FUM) mycotoxin contamination data of corn, daily weather data, satellite data, dynamic geospatial soil properties, and land usage parameters were modeled to identify factors significantly contributing to the outbreaks of mycotoxin contamination of corn grown in Illinois (IL), AFL >20 ppb, and FUM >5 ppm. Two methods were used: a gradient boosting machine (GBM) and a neural network (NN). Both the GBM and NN models were dynamic at a state-county geospatial level because they used GPS coordinates of the counties linked to soil properties. GBM identified temperature and precipitation prior to sowing as significant influential factors contributing to high AFL and FUM contamination. AFL-GBM showed that a higher aflatoxin risk index (ARI) in January, March, July, and November led to higher AFL contamination in the southern regions of IL. Higher values of corn-specific normalized difference vegetation index (NDVI) in July led to lower AFL contamination in Central and Southern IL, while higher wheat-specific NDVI values in February led to higher AFL. FUM-GBM showed that temperature in July and October, precipitation in February, and NDVI values in March are positively correlated with high contamination throughout IL. Furthermore, the dynamic geospatial models showed that soil characteristics were correlated with AFL and FUM contamination. Greater calcium carbonate content in soil was negatively correlated with AFL contamination, which was noticeable in Southern IL. Greater soil moisture and available water-holding capacity throughout Southern IL were positively correlated with high FUM contamination. The higher clay percentage in the northeastern areas of IL negatively correlated with FUM contamination. NN models showed high class-specific performance for 1-year predictive validation for AFL (73%) and FUM (85%), highlighting their accuracy for annual mycotoxin prediction. Our models revealed that soil, NDVI, year-specific weekly average precipitation, and temperature were the most important factors that correlated with mycotoxin contamination. These findings serve as reliable guidelines for future modeling efforts to identify novel data inputs for the prediction of AFL and FUM outbreaks and potential farm-level management practices.
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Affiliation(s)
- Lina Castano-Duque
- Food and Feed Safety Research Unit, Southern Regional Research Center, Agriculture Research Service, United States Department of Agriculture, New Orleans, LA, United States
| | - Edwin Winzeler
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | - Joshua M. Blackstock
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | - Cheng Liu
- Microbiology and Agrochains Wageningen Food Safety Research, Wageningen, Netherlands
| | - Noemi Vergopolan
- Atmospheric and Ocean Science Program, Princeton University, Princeton, NJ, United States
| | - Marlous Focker
- Microbiology and Agrochains Wageningen Food Safety Research, Wageningen, Netherlands
| | - Kristin Barnett
- Agricultural Products Inspection, Illinois Department of Agriculture, Springfield, IL, United States
| | - Phillip Ray Owens
- Dale Bumpers Small Farms Research Center, Agriculture Research Service, United States Department of Agriculture, Booneville, AR, United States
| | | | - Martha M. Vaughan
- Mycotoxin Prevention and Applied Microbiology Research Unit, United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Peoria, IL, United States
| | - Kanniah Rajasekaran
- Food and Feed Safety Research Unit, Southern Regional Research Center, Agriculture Research Service, United States Department of Agriculture, New Orleans, LA, United States
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Felipe MTDC, Barbosa RDN, Bezerra JDP, Souza-Motta CMD. Production of kojic acid by Aspergillus species: Trends and applications. FUNGAL BIOL REV 2023. [DOI: 10.1016/j.fbr.2023.100313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
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6
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Trentin G, Bitencourt TA, Guedes A, Pessoni AM, Brauer VS, Pereira AK, Costa JH, Fill TP, Almeida F. Mass Spectrometry Analysis Reveals Lipids Induced by Oxidative Stress in Candida albicans Extracellular Vesicles. Microorganisms 2023; 11:1669. [PMID: 37512842 PMCID: PMC10383470 DOI: 10.3390/microorganisms11071669] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/02/2023] [Accepted: 06/06/2023] [Indexed: 07/30/2023] Open
Abstract
Candida albicans is a commensal fungus in healthy humans that causes infection in immunocompromised individuals through the secretion of several virulence factors. The successful establishment of infection is owing to elaborate strategies to cope with defensive molecules secreted by the host, including responses toward oxidative stress. Extracellular vesicle (EV) release is considered an alternative to the biomolecule secretory mechanism that favors fungal interactions with the host cells. During candidiasis establishment, the host environment becomes oxidative, and it impacts EV release and cargo. To simulate the host oxidative environment, we added menadione (an oxidative stress inducer) to the culture medium, and we explored C. albicans EV metabolites by metabolomics analysis. This study characterized lipidic molecules transported to an extracellular milieu by C. albicans after menadione exposure. Through Liquid Chromatography coupled with Mass Spectrometry (LC-MS) analyses, we identified biomolecules transported by EVs and supernatant. The identified molecules are related to several biological processes, such as glycerophospholipid and sphingolipid pathways, which may act at different levels by tuning compound production in accordance with cell requirements that favor a myriad of adaptive responses. Taken together, our results provide new insights into the role of EVs in fungal biology and host-pathogen interactions.
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Affiliation(s)
- Gabriel Trentin
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Tamires A Bitencourt
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Arthur Guedes
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - André M Pessoni
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Veronica S Brauer
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
| | - Alana Kelyene Pereira
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas, Campinas 13083-970, Brazil
| | - Jonas Henrique Costa
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas, Campinas 13083-970, Brazil
| | - Taicia Pacheco Fill
- Department of Organic Chemistry, Institute of Chemistry, University of Campinas, Campinas 13083-970, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14049-900, Brazil
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7
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Katati B, Kovacs S, Njapau H, Kachapulula PW, Zwaan BJ, van Diepeningen AD, Schoustra SE. Aflatoxigenic Aspergillus Modulates Aflatoxin-B1 Levels through an Antioxidative Mechanism. J Fungi (Basel) 2023; 9:690. [PMID: 37367626 DOI: 10.3390/jof9060690] [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: 04/28/2023] [Revised: 06/10/2023] [Accepted: 06/12/2023] [Indexed: 06/28/2023] Open
Abstract
Aflatoxins (AFs) are considered to play important functions in species of Aspergillus section Flavi including an antioxidative role, as a deterrent against fungivorous insects, and in antibiosis. Atoxigenic Flavi are known to degrade AF-B1 (B1). To better understand the purpose of AF degradation, we investigated the degradation of B1 and AF-G1 (G1) in an antioxidative role in Flavi. Atoxigenic and toxigenic Flavi were treated with artificial B1 and G1 with or without the antioxidant selenium (Se), which is expected to affect levels of AF. After incubations, AF levels were measured by HPLC. To estimate which population would likely be favoured between toxigenic and atoxigenic Flavi under Se, we investigated the fitness, by spore count, of the Flavi as a result of exposure to 0, 0.40, and 0.86 µg/g Se in 3%-sucrose cornmeal agar (3gCMA). Results showed that levels B1 in medium without Se were reduced in all isolates, while G1 did not significantly change. When the medium was treated with Se, toxigenic Flavi significantly digested less B1, while levels of G1 significantly increased. Se did not affect the digestion of B1 in atoxigenic Flavi, and also did not alter levels of G1. Furthermore, atoxigenic strains were significantly fitter than toxigenic strains at Se 0.86 µg/g 3gCMA. Findings show that while atoxigenic Flavi degraded B1, toxigenic Flavi modulated its levels through an antioxidative mechanism to levels less than they produced. Furthermore, B1 was preferred in the antioxidative role compared to G1 in the toxigenic isolates. The higher fitness of atoxigenic over toxigenic counterparts at a plant non-lethal dose of 0.86 µg/g would be a useful attribute for integration in the broader biocontrol prospects of toxigenic Flavi.
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Affiliation(s)
- Bwalya Katati
- Laboratory of Genetics, Wageningen University and Research, 6708 PB Wageningen, The Netherlands
- Mycotoxicology Laboratory, National Institute for Scientific and Industrial Research, Lusaka 310158, Zambia
| | - Stan Kovacs
- Laboratory of Genetics, Wageningen University and Research, 6708 PB Wageningen, The Netherlands
| | - Henry Njapau
- Mycotoxicology Laboratory, National Institute for Scientific and Industrial Research, Lusaka 310158, Zambia
| | - Paul W Kachapulula
- School of Agricultural Sciences, University of Zambia, Lusaka 10101, Zambia
| | - Bas J Zwaan
- Laboratory of Genetics, Wageningen University and Research, 6708 PB Wageningen, The Netherlands
| | - Anne D van Diepeningen
- Biointeractions and Plant Health, Wageningen University and Research, 6708 PB Wageningen, The Netherlands
| | - Sijmen E Schoustra
- Laboratory of Genetics, Wageningen University and Research, 6708 PB Wageningen, The Netherlands
- School of Agricultural Sciences, University of Zambia, Lusaka 10101, Zambia
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8
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Vargas-Maya NI, Olmedo-Monfil V, Ramírez-Prado JH, Reyes-Cortés R, Padilla-Vaca F, Franco B. Catalases in the pathogenesis of Sporothrix schenckii research. PeerJ 2022; 10:e14478. [PMID: 36523453 PMCID: PMC9745942 DOI: 10.7717/peerj.14478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 11/07/2022] [Indexed: 12/12/2022] Open
Abstract
Pathogenic fungal infection success depends on the ability to escape the immune response. Most strategies for fungal infection control are focused on the inhibition of virulence factors and increasing the effectiveness of antifungal drugs. Nevertheless, little attention has been focused on their physiological resistance to the host immune system. Hints may be found in pathogenic fungi that also inhabit the soil. In nature, the saprophyte lifestyle of fungi is also associated with predators that can induce oxidative stress upon cell damage. The natural sources of nutrients for fungi are linked to cellulose degradation, which in turn generates reactive oxygen species (ROS). Overall, the antioxidant arsenal needed to thrive both in free-living and pathogenic lifestyles in fungi is fundamental for success. In this review, we present recent findings regarding catalases and oxidative stress in fungi and how these can be in close relationship with pathogenesis. Additionally, special focus is placed on catalases of Sporothrix schenckii as a pathogenic model with a dual lifestyle. It is assumed that catalase expression is activated upon exposure to H2O2, but there are reports where this is not always the case. Additionally, it may be relevant to consider the role of catalases in S. schenckii survival in the saprophytic lifestyle and why their study can assess their involvement in the survival and therefore, in the virulence phenotype of different species of Sporothrix and when each of the three catalases are required. Also, studying antioxidant mechanisms in other isolates of pathogenic and free-living fungi may be linked to the virulence phenotype and be potential therapeutic and diagnostic targets. Thus, the rationale for this review to place focus on fungal catalases and their role in pathogenesis in addition to counteracting the effect of immune system reactive oxygen species. Fungi that thrive in soil and have mammal hosts could shed light on the importance of these enzymes in the two types of lifestyles. We look forward to encouraging more research in a myriad of areas on catalase biology with a focus on basic and applied objectives and placing these enzymes as virulence determinants.
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Affiliation(s)
| | | | | | - Ruth Reyes-Cortés
- Biology Department, Universidad de Guanajuato, Guanajuato, Guanajuato, México
| | - Felipe Padilla-Vaca
- Biology Department, Universidad de Guanajuato, Guanajuato, Guanajuato, México
| | - Bernardo Franco
- Biology Department, Universidad de Guanajuato, Guanajuato, Guanajuato, México
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9
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Castano-Duque L, Lebar MD, Carter-Wientjes C, Ambrogio D, Rajasekaran K. Flavonoids Modulate Aspergillus flavus Proliferation and Aflatoxin Production. J Fungi (Basel) 2022; 8:1211. [PMID: 36422032 PMCID: PMC9693025 DOI: 10.3390/jof8111211] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/02/2022] [Accepted: 11/10/2022] [Indexed: 08/26/2023] Open
Abstract
Aflatoxins are carcinogenic mycotoxins produced by Aspergillus flavus. They contaminate major food crops, particularly corn, and pose a worldwide health concern. Flavonoid production has been correlated to resistance to aflatoxin accumulation in corn. The effects of flavonoids on fungal proliferation and aflatoxin production are not well understood. In this study, we performed bioassays, fluorescence and scanning electron microscopy, and total antioxidant analysis to determine the effects of three flavonoids (apigenin, luteolin, and quercetin) on proliferation and aflatoxin production in A. flavus NRRL 3357. Results showed that concentrations of apigenin and luteolin modulated fungal proliferation and aflatoxin production in a dose-dependent manner, leading to inhibition or promotion of proliferation and toxin production. Microscopy studies of fungi exposed to flavonoids showed mycelial cell wall disruption, abnormal cell wall invaginations, and tears. Fluorescent enhancement of apigenin and luteolin using Naturstoff reagent A showed that these chemicals localized in sphere-like structures on the mycelia surface. Fungi exposed to low concentrations of apigenin, luteolin, and quercetin lowered the total antioxidant capacity in the environment compared to controls. Our results indicate that flavonoids disrupt cell wall integrity and may localize in vesicle-like structures. We hypothesize that flavonoids could act as potential signaling molecules at low concentrations and change the oxidative state of the microenvironment, either or both of which may lead to reduction of fungal proliferation and aflatoxin production.
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Affiliation(s)
- Lina Castano-Duque
- United States Department of Agriculture—Agriculture Research Services, New Orleans, LA 70124, USA
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10
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Pérez-Pérez WD, Carrasco-Navarro U, García‑Estrada C, Kosalková K, Gutiérrez-Ruíz MC, Barrios-González J, Fierro F. bZIP transcription factors PcYap1 and PcRsmA link oxidative stress response to secondary metabolism and development in Penicillium chrysogenum. Microb Cell Fact 2022; 21:50. [PMID: 35366869 PMCID: PMC8977021 DOI: 10.1186/s12934-022-01765-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 02/27/2022] [Indexed: 01/23/2023] Open
Abstract
Abstract
Background
Reactive oxygen species (ROS) trigger different morphogenic processes in filamentous fungi and have been shown to play a role in the regulation of the biosynthesis of some secondary metabolites. Some bZIP transcription factors, such as Yap1, AtfA and AtfB, mediate resistance to oxidative stress and have a role in secondary metabolism regulation. In this work we aimed to get insight into the molecular basis of this regulation in the industrially important fungus Penicillium chrysogenum through the characterization of the role played by two effectors that mediate the oxidative stress response in development and secondary metabolism.
Results
In P. chrysogenum, penicillin biosynthesis and conidiation are stimulated by the addition of H2O2 to the culture medium, and this effect is mediated by the bZIP transcription factors PcYap1 and PcRsmA. Silencing of expression of both proteins by RNAi resulted in similar phenotypes, characterized by increased levels of ROS in the cell, reduced conidiation, higher sensitivity of conidia to H2O2 and a decrease in penicillin production. Both PcYap1 and PcRsmA are able to sense H2O2-generated ROS in vitro and change its conformation in response to this stimulus. PcYap1 and PcRsmA positively regulate the expression of brlA, the first gene of the conidiation central regulatory pathway. PcYap1 binds in vitro to a previously identified regulatory sequence in the promoter of the penicillin gene pcbAB: TTAGTAA, and to a TTACTAA sequence in the promoter of the brlA gene, whereas PcRsmA binds to the sequences TGAGACA and TTACGTAA (CRE motif) in the promoters of the pcbAB and penDE genes, respectively.
Conclusions
bZIP transcription factors PcYap1 and PcRsmA respond to the presence of H2O2-generated ROS and regulate oxidative stress response in the cell. Both proteins mediate ROS regulation of penicillin biosynthesis and conidiation by binding to specific regulatory elements in the promoters of key genes. PcYap1 is identified as the previously proposed transcription factor PTA1 (Penicillin Transcriptional Activator 1), which binds to the regulatory sequence TTAGTAA in the pcbAB gene promoter. This is the first report of a Yap1 protein directly regulating transcription of a secondary metabolism gene. A model describing the regulatory network mediated by PcYap1 and PcRsmA is proposed.
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11
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Development of sexual structures influences metabolomic and transcriptomic profiles in Aspergillus flavus. Fungal Biol 2022; 126:187-200. [DOI: 10.1016/j.funbio.2022.01.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 01/02/2023]
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12
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Mahanty S, Tudu P, Ghosh S, Chatterjee S, Das P, Bhattacharyya S, Das S, Acharya K, Chaudhuri P. Chemometric study on the biochemical marker of the manglicolous fungi to illustrate its potentiality as a bio indicator for heavy metal pollution in Indian Sundarbans. MARINE POLLUTION BULLETIN 2021; 173:113017. [PMID: 34872165 DOI: 10.1016/j.marpolbul.2021.113017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 09/24/2021] [Accepted: 09/28/2021] [Indexed: 06/13/2023]
Abstract
The study represents in vitro chemometric approach for assessing the heavy metal pollution in Indian Sundarbans. Physio-chemical and elemental characterisation of the sediment samples of Indian Sundarbans had shown high enrichments of toxic metal ions. It was characterised by elevated enrichment factors (2.16-10.12), geo-accumulation indices (0.03 -1.21), contamination factors (0.7-3.43) and pollution load indices (1.0-1.25) which showed progressive sediment quality deterioration and ecotoxicological risk due to metal ions contamination. The physio-chemical parameters of the sediments were replicated and computational chemometric modeling was utilized to assess fungal metabolic growth. All the fungi isolates had shown maximum metabolic activity in high temperature, alkaline pH, and high salinity. Further, the fungal metabolic activity was assessed in different gradient of heavy metal concentration. The significant deterioration of biochemical marker with increasing concentration of heavy metal indicates the status of the microbial health due to toxic metal pollution in the mangrove habitat.
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Affiliation(s)
- Shouvik Mahanty
- Department of Environmental Science, University of Calcutta, India
| | - Praveen Tudu
- Department of Environmental Science, University of Calcutta, India
| | - Somdeep Ghosh
- Department of Environmental Science, University of Calcutta, India
| | | | - Papita Das
- Department of Chemical Engineering, Jadavpur University, India
| | | | - Surajit Das
- Department of Life Science, NIT Rourkela, India
| | - Krishnendu Acharya
- Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, India
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13
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Zhong Z, McDonald BA, Palma-Guerrero J. Tolerance to oxidative stress is associated with both oxidative stress response and inherent growth in a fungal wheat pathogen. Genetics 2021; 217:6029569. [PMID: 33724407 DOI: 10.1093/genetics/iyaa022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/23/2020] [Indexed: 01/25/2023] Open
Abstract
Reactive oxygen species are toxic byproducts of aerobic respiration that are also important in mediating a diversity of cellular functions. Reactive oxygen species form an important component of plant defenses to inhibit microbial pathogens during pathogen-plant interactions. Tolerance to oxidative stress is likely to make a significant contribution to the viability and pathogenicity of plant pathogens, but the complex network of oxidative stress responses hinders identification of the genes contributing to this trait. Here, we employed a forward genetic approach to investigate the genetic architecture of oxidative stress tolerance in the fungal wheat pathogen Zymoseptoria tritici. We used quantitative trait locus (QTL) mapping of growth and melanization under axenic conditions in two cross-populations to identify genomic regions associated with tolerance to oxidative stress. We found that QTLs associated with growth under oxidative stress as well as inherent growth can affect oxidative stress tolerance, and we identified two uncharacterized genes in a major QTL associated with this trait. Our data suggest that melanization does not affect tolerance to oxidative stress, which differs from what was found for animal pathogens. This study provides a whole-genome perspective on the genetic basis of oxidative stress tolerance in a plant pathogen.
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Affiliation(s)
- Ziming Zhong
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Bruce A McDonald
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland
| | - Javier Palma-Guerrero
- Plant Pathology Group, Institute of Integrative Biology, ETH Zurich, 8092 Zürich, Switzerland.,Department of Biointeractions and Crop Protection, Rothamsted Research, AL5 2JQ Harpenden, UK
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14
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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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15
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Zhang H, Yue P, Tong X, Bai J, Yang J, Guo J. mRNA-seq and miRNA-seq profiling analyses reveal molecular mechanisms regulating induction of fruiting body in Ophiocordyceps sinensis. Sci Rep 2021; 11:12944. [PMID: 34155233 PMCID: PMC8217512 DOI: 10.1038/s41598-021-91718-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 05/24/2021] [Indexed: 02/05/2023] Open
Abstract
Ophiocordyceps sinensis has been a source of valuable materials in traditional Asian medicine for over two thousand years. With recent global warming and overharvest, however, the availability of these wild fungi has decreased dramatically. While fruiting body of O. sinensis has been artificially cultivated, the molecular mechanisms that govern the induction of fruiting body at the transcriptional and post-transcriptional levels are unclear. In this study, we carried out both mRNA and small RNA sequencing to identify crucial genes and miRNA-like RNAs (milRNAs) involved in the development of fruiting body. A total of 2875 differentially expressed genes (DEGs), and 71 differentially expressed milRNAs (DEMs) were identified among the mycoparasite complex, the sclerotium (ST) and the fruiting body stage. Functional enrichment and Gene Set Enrichment Analysis indicated that the ST had increased oxidative stress and energy metabolism and that mitogen-activated protein kinase signaling might induce the formation of fruiting body. Integrated analysis of DEGs and DEMs revealed that n_os_milR16, n_os_milR21, n_os_milR34, and n_os_milR90 could be candidate milRNAs that regulate the induction of fruiting body. This study provides transcriptome-wide insight into the molecular basis of fruiting body formation in O. Sinensis and identifies potential candidate genes for improving induction rate.
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Affiliation(s)
- Han Zhang
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
- State Key Laboratory of Grassland Agro-Ecosystem, Institute of Innovation Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Pan Yue
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Xinxin Tong
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jing Bai
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jingyan Yang
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China
| | - Jinlin Guo
- Key Laboratory of Standardization of Chinese Medicine, Ministry of Education; Key Laboratory of Systematic Research of Distinctive Chinese Medicine Resources in Southwest China, Resources Breeding Base of Co-Founded By Sichuan Province and MOST, Chengdu University of Traditional Chinese Medicine, Chengdu, 611137, China.
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16
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Jannatizadeh A, Aminian‐Dehkordi R, Razavi F. Effect of exogenous melatonin treatment on
Aspergillus
decay, aflatoxin B1 accumulation and nutritional quality of fresh “Akbari” pistachio fruit. J FOOD PROCESS PRES 2021. [DOI: 10.1111/jfpp.15518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Abbasali Jannatizadeh
- Department of Horticultural Science Imam Khomeini International University Qazvin Iran
| | - Roghayeh Aminian‐Dehkordi
- Department of Genetics and Plant Breeding Faculty of Agriculture and Natural Resources Imam Khomeini International University Qazvin Iran
| | - Farhang Razavi
- Department of Horticulture Faculty of Agriculture University of Zanjan Zanjan Iran
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17
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Soni P, Pandey AK, Nayak SN, Pandey MK, Tolani P, Pandey S, Sudini HK, Bajaj P, Fountain JC, Singam P, Guo B, Varshney RK. Global Transcriptome Profiling Identified Transcription Factors, Biological Process, and Associated Pathways for Pre-Harvest Aflatoxin Contamination in Groundnut. J Fungi (Basel) 2021; 7:413. [PMID: 34073230 PMCID: PMC8227191 DOI: 10.3390/jof7060413] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/20/2021] [Accepted: 05/23/2021] [Indexed: 11/24/2022] Open
Abstract
Pre-harvest aflatoxin contamination (PAC) in groundnut is a serious quality concern globally, and drought stress before harvest further exacerbate its intensity, leading to the deterioration of produce quality. Understanding the host-pathogen interaction and identifying the candidate genes responsible for resistance to PAC will provide insights into the defense mechanism of the groundnut. In this context, about 971.63 million reads have been generated from 16 RNA samples under controlled and Aspergillus flavus infected conditions, from one susceptible and seven resistant genotypes. The RNA-seq analysis identified 45,336 genome-wide transcripts under control and infected conditions. This study identified 57 transcription factor (TF) families with major contributions from 6570 genes coding for bHLH (719), MYB-related (479), NAC (437), FAR1 family protein (320), and a few other families. In the host (groundnut), defense-related genes such as senescence-associated proteins, resveratrol synthase, seed linoleate, pathogenesis-related proteins, peroxidases, glutathione-S-transferases, chalcone synthase, ABA-responsive gene, and chitinases were found to be differentially expressed among resistant genotypes as compared to susceptible genotypes. This study also indicated the vital role of ABA-responsive ABR17, which co-regulates the genes of ABA responsive elements during drought stress, while providing resistance against A. flavus infection. It belongs to the PR-10 class and is also present in several plant-pathogen interactions.
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Affiliation(s)
- Pooja Soni
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
- Department of Genetics, Osmania University, Hyderabad 500007, India;
| | - Arun K. Pandey
- College of Life Science, China Jiliang University (CJLU), Hangzhou 310018, China;
| | - Spurthi N. Nayak
- Department of Biotechnology, University of Agricultural Sciences, Dharwad 580005, India;
| | - Manish K. Pandey
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
| | - Priya Tolani
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
| | - Sarita Pandey
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
| | - Hari K. Sudini
- Theme-Integrated Crop Improvement, Research Program-Asia, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India;
| | - Prasad Bajaj
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
| | - Jake C. Fountain
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Starkville, MS 39762, USA;
| | - Prashant Singam
- Department of Genetics, Osmania University, Hyderabad 500007, India;
| | - Baozhu Guo
- Crop Genetics and Breeding Research Unit, USDA-ARS, Tifton, GA 31793, USA;
| | - Rajeev K. Varshney
- Center of Excellence in Genomics & Systems Biology (CEGSB), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad 502324, India; (P.S.); (M.K.P.); (P.T.); (S.P.); (P.B.)
- State Agricultural Biotechnology Centre, Centre for Crop and Food Innovation, Food Futures Institute, Murdoch University, Murdoch, WA 6150, Australia
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18
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Singh Y, Nair AM, Verma PK. Surviving the odds: From perception to survival of fungal phytopathogens under host-generated oxidative burst. PLANT COMMUNICATIONS 2021; 2:100142. [PMID: 34027389 PMCID: PMC8132124 DOI: 10.1016/j.xplc.2021.100142] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/04/2020] [Accepted: 01/01/2021] [Indexed: 05/04/2023]
Abstract
Fungal phytopathogens pose a serious threat to global crop production. Only a handful of strategies are available to combat these fungal infections, and the increasing incidence of fungicide resistance is making the situation worse. Hence, the molecular understanding of plant-fungus interactions remains a primary focus of plant pathology. One of the hallmarks of host-pathogen interactions is the overproduction of reactive oxygen species (ROS) as a plant defense mechanism, collectively termed the oxidative burst. In general, high accumulation of ROS restricts the growth of pathogenic organisms by causing localized cell death around the site of infection. To survive the oxidative burst and achieve successful host colonization, fungal phytopathogens employ intricate mechanisms for ROS perception, ROS neutralization, and protection from ROS-mediated damage. Together, these countermeasures maintain the physiological redox homeostasis that is essential for cell viability. In addition to intracellular antioxidant systems, phytopathogenic fungi also deploy interesting effector-mediated mechanisms for extracellular ROS modulation. This aspect of plant-pathogen interactions is significantly under-studied and provides enormous scope for future research. These adaptive responses, broadly categorized into "escape" and "exploitation" mechanisms, are poorly understood. In this review, we discuss the oxidative stress response of filamentous fungi, their perception signaling, and recent insights that provide a comprehensive understanding of the distinct survival mechanisms of fungal pathogens in response to the host-generated oxidative burst.
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Affiliation(s)
- Yeshveer Singh
- Plant Immunity Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Athira Mohandas Nair
- Plant Immunity Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Praveen Kumar Verma
- Plant Immunity Laboratory, National Institute of Plant Genome Research, Aruna Asaf Ali Marg, New Delhi 110067, India
- School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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19
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Zhang Y, Chen Z, Wen Q, Xiong Z, Cao X, Zheng Z, Zhang Y, Huang Z. An overview on the biosynthesis and metabolic regulation of monacolin K/lovastatin. Food Funct 2021; 11:5738-5748. [PMID: 32555902 DOI: 10.1039/d0fo00691b] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Lovastatin/monacolin K (MK) is used as a lipid lowering drug, due to its effective hypercholesterolemic properties, comparable to synthetic statins. Lovastatin's biosynthetic pathway and gene cluster composition have been studied in depth in Aspergillus terreus. Evidence shows that the MK biosynthetic pathway and gene cluster in Monascus sp. are similar to those of lovastatin in A. terreus. Currently, research efforts have been focusing on the metabolic regulation of MK/lovastatin synthesis, and the evidence shows that a combination of extracellular and intracellular factors is essential for proper MK/lovastatin metabolism. Here, we comprehensively review the research progress on MK/lovastatin biosynthetic pathways, its synthetic precursors and inducing substances and metabolic regulation, with a view to providing reference for future research on fungal metabolism regulation and metabolic engineering for MK/lovastatin production.
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Affiliation(s)
- Yaru Zhang
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. and Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zhiting Chen
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. and Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Qinyou Wen
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. and Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Zixiao Xiong
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. and Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaohua Cao
- Key Laboratory of Crop Biotechnology (Fujian Agriculture and Forestry University), Fujian Province University, Fuzhou 350002, China
| | - Zhenghuai Zheng
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yangxin Zhang
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zhiwei Huang
- College of Food Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China. and Fujian Provincial Key Laboratory of Quality Science and Processing Technology in Special Starch, Fujian Agriculture and Forestry University, Fuzhou 350002, China and China-Ireland International Cooperation Centre for Food Material Science and Structure Design, Fujian Agriculture and Forestry University, Fuzhou 350002, China
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20
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Tian F, Lee SY, Woo SY, Choi HY, Heo S, Nah G, Chun HS. Transcriptomic responses of Aspergillus flavus to temperature and oxidative stresses during aflatoxin production. Sci Rep 2021; 11:2803. [PMID: 33531617 PMCID: PMC7854668 DOI: 10.1038/s41598-021-82488-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/18/2021] [Indexed: 01/30/2023] Open
Abstract
Aflatoxin is a group of polyketide-derived carcinogenic and mutagenic secondary metabolites produced by Aspergillus flavus that negatively impact global food security and threaten the health of both humans and livestock. Aflatoxin biosynthesis is strongly affected by the fungal developmental stage, cultivation conditions, and environmental stress. In this study, a novel float culture method was used to examine the direct responses of the A. flavus transcriptome to temperature stress, oxidative stress, and their dual effects during the aflatoxin production stage. The transcriptomic response of A. flavus illustrated that the co-regulation of different secondary metabolic pathways likely contributes to maintaining cellular homeostasis and promoting cell survival under stress conditions. In particular, aflatoxin biosynthetic gene expression was downregulated, while genes encoding secondary metabolites with antioxidant properties, such as kojic acid and imizoquins, were upregulated under stress conditions. Multiple mitochondrial function-related genes, including those encoding NADH:ubiquinone oxidoreductase, ubiquinol-cytochrome C reductase, and alternative oxidase, were differentially expressed. These data can provide insights into the important mechanisms through which secondary metabolism in A. flavus is co-regulated and facilitate the deployment of various approaches for the effective control and prevention of aflatoxin contamination in food crops.
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Affiliation(s)
- Fei Tian
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Sang Yoo Lee
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - So Young Woo
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Hwa Young Choi
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Seongeun Heo
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
| | - Gyoungju Nah
- grid.31501.360000 0004 0470 5905Genome Analysis Center at National Instrumentation Center for Environmental Management, Seoul National University, Seoul, Korea
| | - Hyang Sook Chun
- grid.254224.70000 0001 0789 9563Food Toxicology Laboratory, School of Food Science and Technology, Chung-Ang University, Anseong, Korea
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21
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Fountain J, Pandey A, Nayak S, Bajaj P, Wang H, Kumar V, Chitikineni A, Abbas H, Scully B, Kemerait R, Pandey M, Guo B, Varshney R. Transcriptional responses of toxigenic and atoxigenic isolates of Aspergillus flavus to oxidative stress in aflatoxin-conducive and non-conducive media. WORLD MYCOTOXIN J 2020. [DOI: 10.3920/wmj2020.2566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Aflatoxin production by isolates of Aspergillus flavus varies, ranging from highly toxigenic to completely atoxigenic. Several mechanisms have been identified which regulate aflatoxin production including medium carbon source and oxidative stress. In recent studies, aflatoxin production has been implicated in partially ameliorating oxidative stress in A. flavus. To better understand the role of aflatoxin production in oxidative stress responses, a selection of toxigenic and atoxigenic isolates of A. flavus with moderate to high oxidative stress tolerance were exposed to increasing concentrations of H2O2 in both aflatoxin-conducive and non-conducive media. Mycelial mats were collected for global transcriptome sequencing followed by differential expression, functional prediction, and weighted co-expression analyses. Oxidative stress and medium carbon source had a significant effect on the expression of several secondary metabolite gene clusters including those for aflatoxin, aflatrem, aflavarin, cyclopiazonic acid, and kojic acid. Atoxigenic biological control isolates showed less differential expression under stress than other atoxigenic isolates suggesting expression profiles may be useful in screening. Increasing stress also resulted in regulation of SakA/Hog1 and MpkA MAP kinase signalling pathways pointing to their potential roles in regulating oxidative stress responses. Their expression was also influenced by medium carbon source. These results suggest that aflatoxin production along with that of other mycotoxins may occur as part of a concerted coping mechanism for oxidative stress and its effects in the environment. This mechanism is also regulated by availability of simple sugars and glycolytic compounds for their biosynthesis.
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Affiliation(s)
- J.C. Fountain
- USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA 31793, USA
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA
- Department of Biochemistry, Molecular Biology, Entomology, and Plant Pathology, Mississippi State University, Starkville, MS 39762, USA
| | - A.K. Pandey
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
| | - S.N. Nayak
- Department of Biotechnology, University of Agricultural Sciences, Dharwad, Karnataka 580005, India
| | - P. Bajaj
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
| | - H. Wang
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA
| | - V. Kumar
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
| | - A. Chitikineni
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
| | - H.K. Abbas
- USDA-ARS, Biological Control of Pests Research Unit, Stoneville, MS, USA
| | - B.T. Scully
- USDA-ARS, National Horticultural Research Laboratory, Fort Pierce, FL, USA
| | - R.C. Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA
| | - M.K. Pandey
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
| | - B. Guo
- USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA 31793, USA
| | - R.K. Varshney
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana 502324, India
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Vicente I, Baroncelli R, Morán-Diez ME, Bernardi R, Puntoni G, Hermosa R, Monte E, Vannacci G, Sarrocco S. Combined Comparative Genomics and Gene Expression Analyses Provide Insights into the Terpene Synthases Inventory in Trichoderma. Microorganisms 2020; 8:E1603. [PMID: 33081019 PMCID: PMC7603203 DOI: 10.3390/microorganisms8101603] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 12/11/2022] Open
Abstract
Trichoderma is a fungal genus comprising species used as biocontrol agents in crop plant protection and with high value for industry. The beneficial effects of these species are supported by the secondary metabolites they produce. Terpenoid compounds are key players in the interaction of Trichoderma spp. with the environment and with their fungal and plant hosts; however, most of the terpene synthase (TS) genes involved in their biosynthesis have yet not been characterized. Here, we combined comparative genomics of TSs of 21 strains belonging to 17 Trichoderma spp., and gene expression studies on TSs using T. gamsii T6085 as a model. An overview of the diversity within the TS-gene family and the regulation of TS genes is provided. We identified 15 groups of TSs, and the presence of clade-specific enzymes revealed a variety of terpenoid chemotypes evolved to cover different ecological demands. We propose that functional differentiation of gene family members is the driver for the high number of TS genes found in the genomes of Trichoderma. Expression studies provide a picture in which different TS genes are regulated in many ways, which is a strong indication of different biological functions.
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Affiliation(s)
- Isabel Vicente
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy; (R.B.); (G.P.); (G.V.); (S.S.)
- Department of Microbiology and Genetics, Spanish-Portuguese Institute for Agricultural Research (CIALE), University of Salamanca, Campus Villamayor, 37185 Salamanca, Spain; (R.B.); (M.E.M.-D.); (R.H.); (E.M.)
| | - Riccardo Baroncelli
- Department of Microbiology and Genetics, Spanish-Portuguese Institute for Agricultural Research (CIALE), University of Salamanca, Campus Villamayor, 37185 Salamanca, Spain; (R.B.); (M.E.M.-D.); (R.H.); (E.M.)
| | - María Eugenia Morán-Diez
- Department of Microbiology and Genetics, Spanish-Portuguese Institute for Agricultural Research (CIALE), University of Salamanca, Campus Villamayor, 37185 Salamanca, Spain; (R.B.); (M.E.M.-D.); (R.H.); (E.M.)
| | - Rodolfo Bernardi
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy; (R.B.); (G.P.); (G.V.); (S.S.)
| | - Grazia Puntoni
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy; (R.B.); (G.P.); (G.V.); (S.S.)
| | - Rosa Hermosa
- Department of Microbiology and Genetics, Spanish-Portuguese Institute for Agricultural Research (CIALE), University of Salamanca, Campus Villamayor, 37185 Salamanca, Spain; (R.B.); (M.E.M.-D.); (R.H.); (E.M.)
| | - Enrique Monte
- Department of Microbiology and Genetics, Spanish-Portuguese Institute for Agricultural Research (CIALE), University of Salamanca, Campus Villamayor, 37185 Salamanca, Spain; (R.B.); (M.E.M.-D.); (R.H.); (E.M.)
| | - Giovanni Vannacci
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy; (R.B.); (G.P.); (G.V.); (S.S.)
| | - Sabrina Sarrocco
- Department of Agriculture, Food and Environment, University of Pisa, 56124 Pisa, Italy; (R.B.); (G.P.); (G.V.); (S.S.)
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Two New Aspergillus flavus Reference Genomes Reveal a Large Insertion Potentially Contributing to Isolate Stress Tolerance and Aflatoxin Production. G3-GENES GENOMES GENETICS 2020; 10:3515-3531. [PMID: 32817124 PMCID: PMC7534430 DOI: 10.1534/g3.120.401405] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Efforts in genome sequencing in the Aspergillus genus have led to the development of quality reference genomes for several important species including A. nidulans, A. fumigatus, and A. oryzae However, less progress has been made for A. flavus As part of the effort of the USDA-ARS Annual Aflatoxin Workshop Fungal Genome Project, the isolate NRRL3357 was sequenced and resulted in a scaffold-level genome released in 2005. Our goal has been biologically driven, focusing on two areas: isolate variation in aflatoxin production and drought stress exacerbating aflatoxin production by A. flavus Therefore, we developed two reference pseudomolecule genome assemblies derived from chromosome arms for two isolates: AF13, a MAT1-2, highly stress tolerant, and highly aflatoxigenic isolate; and NRRL3357, a MAT1-1, less stress tolerant, and moderate aflatoxin producer in comparison to AF13. Here, we report these two reference-grade assemblies for these isolates through a combination of PacBio long-read sequencing and optical mapping, and coupled them with comparative, functional, and phylogenetic analyses. This analysis resulted in the identification of 153 and 45 unique genes in AF13 and NRRL3357, respectively. We also confirmed the presence of a unique 310 Kb insertion in AF13 containing 60 genes. Analysis of this insertion revealed the presence of a bZIP transcription factor, named atfC, which may contribute to isolate pathogenicity and stress tolerance. Phylogenomic analyses comparing these and other available assemblies also suggest that the species complex of A. flavus is polyphyletic.
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Kalagatur NK, Gurunathan S, Kamasani JR, Gunti L, Kadirvelu K, Mohan CD, Rangappa S, Prasad R, Almeida F, Mudili V, Siddaiah C. Inhibitory effect of C. zeylanicum, C. longa, O. basilicum, Z. officinale, and C. martini essential oils on growth and ochratoxin A content of A. ochraceous and P. verrucosum in maize grains. ACTA ACUST UNITED AC 2020; 27:e00490. [PMID: 32637345 PMCID: PMC7327888 DOI: 10.1016/j.btre.2020.e00490] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/23/2020] [Accepted: 06/15/2020] [Indexed: 12/25/2022]
Abstract
Essenetial oils (EOs) extrcated by hydrodistillation and chemical profile deduced by GC–MS. EOs shown potential antioxidant activity by DPPH and ABTS assay. EOs presented superlative antifungal activity against P. verrucosum related to A. ochraceus. C. zeylanicum and C. martini EOs presented superlative antifungal activity related to other EOs. C. zeylanicum EO inhibited the growth and OTA of fungi at 1500 μg/g in maize grains.
In the study, antifungal and ochratoxin A (OTA) production inhibitory activities of essential oils (EOs) of Cinnamomum zeylanicum, Curcuma longa, Ocimum basilicum, Zingiber officinale, and Cymbopogon martini were reported on Aspergillus ochraceus and Penicillium verrucosum. EOs were obtained by hydrodistillation and GC–MS technique was chosen to deduce their chemical profile. Major chemical compounds in EOs of C. zeylanicum, C. longa, O. basilicum, Z. officinale, and C. martini were (E)-cinnamaldehyde (35.81 %), ar-turmerone (46.13 %), eugenol (36.58 %), geranyl proprionate (18.93 %), and geranyl acetate (14.88 %), respectively. The EOs shown potent antioxidant activity by DPPH and ABTS assays. The EOs presented superlative antifungal activity against P. verrucosum related to A. ochraceus. The C. zeylanicum and C. martini EOs shown superlative antifungal activity related to other EOs. The C. zeylanicum and C. martini EOs completely inhibited the growth and OTA production of P. verrucosum and A. ochraceous at 1500 and 2500 μg/g in maize grains, respectively.
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Affiliation(s)
- Naveen Kumar Kalagatur
- DRDO-BU-Centre for Life Sciences, Bharathiar University Campus, Coimbatore, 641046, India
| | - Selvakumar Gurunathan
- Center for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore, 641003, India
| | - Jalarama Reddy Kamasani
- Freeze Drying and Animal Products Technology, Defence Food Research Laboratory, Mysuru, 570011, India
| | - Lokanadhan Gunti
- Department of Microbiology, Pondicherry University, Pondicherry, 605014, India
| | - Krishna Kadirvelu
- DRDO-BU-Centre for Life Sciences, Bharathiar University Campus, Coimbatore, 641046, India
| | | | - Shobith Rangappa
- Adichunchanagiri Institute for Molecular Medicine, Mandya, 571448, India
| | - Ram Prasad
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou, 510006, China.,Department of Botany, School of Life Sciences, Mahatma Gandhi Central University, Motihari, 845401, India
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirao Preto Medical School, University of Sao Paulo, Ribeirao Preto, SP, 14049-900, Brazil
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25
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Pang KL, Chiang MWL, Guo SY, Shih CY, Dahms HU, Hwang JS, Cha HJ. Growth study under combined effects of temperature, pH and salinity and transcriptome analysis revealed adaptations of Aspergillus terreus NTOU4989 to the extreme conditions at Kueishan Island Hydrothermal Vent Field, Taiwan. PLoS One 2020; 15:e0233621. [PMID: 32453769 PMCID: PMC7250430 DOI: 10.1371/journal.pone.0233621] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 05/08/2020] [Indexed: 12/03/2022] Open
Abstract
A high diversity of fungi was discovered on various substrates collected at the marine shallow-water Kueishan Island Hydrothermal Vent Field, Taiwan, using culture and metabarcoding methods but whether these fungi can grow and play an active role in such an extreme environment is unknown. We investigated the combined effects of different salinity, temperature and pH on growth of ten fungi (in the genera Aspergillus, Penicillium, Fodinomyces, Microascus, Trichoderma, Verticillium) isolated from the sediment and the vent crab Xenograpsus testudinatus. The growth responses of the tested fungi could be referred to three groups: (1) wide pH, salinity and temperature ranges, (2) salinity-dependent and temperature-sensitive, and (3) temperature-tolerant. Aspergillus terreus NTOU4989 was the only fungus which showed growth at 45 °C, pH 3 and 30 ‰ salinity, and might be active near the vents. We also carried out a transcriptome analysis to understand the molecular adaptations of A. terreus NTOU4989 under these extreme conditions. Data revealed that stress-related genes were differentially expressed at high temperature (45 °C); for instance, mannitol biosynthetic genes were up-regulated while glutathione S-transferase and amino acid oxidase genes down-regulated in response to high temperature. On the other hand, hydrogen ion transmembrane transport genes and phenylalanine ammonia lyase were up-regulated while pH-response transcription factor was down-regulated at pH 3, a relative acidic environment. However, genes related to salt tolerance, such as glycerol lipid metabolism and mitogen-activated protein kinase, were up-regulated in both conditions, possibly related to maintaining water homeostasis. The results of this study revealed the genetic evidence of adaptation in A. terreus NTOU4989 to changes of environmental conditions.
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Affiliation(s)
- Ka-Lai Pang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | | | - Sheng-Yu Guo
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Chi-Yu Shih
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hans U Dahms
- Department of Biomedical Science and Environment Biology, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jiang-Shiou Hwang
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
| | - Hyo-Jung Cha
- Institute of Marine Biology and Centre of Excellence for the Oceans, National Taiwan Ocean University, Keelung, Taiwan
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26
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Zhu Z, Yang M, Bai Y, Ge F, Wang S. Antioxidant-related catalase CTA1 regulates development, aflatoxin biosynthesis, and virulence in pathogenic fungus Aspergillus flavus. Environ Microbiol 2020; 22:2792-2810. [PMID: 32250030 DOI: 10.1111/1462-2920.15011] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/17/2020] [Accepted: 03/31/2020] [Indexed: 11/29/2022]
Abstract
Reactive oxygen species (ROS) induce the synthesis of a myriad of secondary metabolites, including aflatoxins. It raises significant concern as it is a potent environmental contaminant. In Aspergillus flavus., antioxidant enzymes link ROS stress response with coordinated gene regulation of aflatoxin biosynthesis. In this study, we characterized the function of a core component of the antioxidant enzyme catalase (CTA1) of A. flavus. Firstly, we verified the presence of cta1 corresponding protein (CTA1) by Western blot analysis and mass-spectrometry based analysis. Then, the functional study revealed that the growth, sporulation and sclerotia formation significantly increased, while aflatoxins production and virulence were decreased in the cta1 deletion mutant as compared with the WT and complementary strains. Furthermore, the absence of the cta1 gene resulted in a significant rise in the intracellular ROS level, which in turn added to the oxidative stress level of cells. A further quantitative proteomics investigation hinted that in vivo, CTA1 might maintain the ROS level to facilitate the aflatoxin synthesis. All in all, the pleiotropic phenotype of A. flavus CTA1 deletion mutant revealed that the antioxidant system plays a crucial role in fungal development, aflatoxins biosynthesis and virulence.
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Affiliation(s)
- Zhuo Zhu
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Mingkun Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.,State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Youhuang Bai
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Feng Ge
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
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27
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Aghdam MS, Luo Z, Aminian-Dehkordi R, Jannatizadeh A, Farmani B, Younessi-Hamzekhanlu M, Ahmadpour A, Razavi F. Exogenous β-aminobutyric acid application attenuates Aspergillus decay, minimizes aflatoxin B 1 accumulation, and maintains nutritional quality in fresh-in-hull pistachio kernels. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2020; 100:2130-2135. [PMID: 31884686 DOI: 10.1002/jsfa.10236] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/23/2019] [Accepted: 12/30/2019] [Indexed: 05/24/2023]
Abstract
BACKGROUND Pistachio fruits suffer from postharvest decay, caused by Aspergillus flavus. This results in aflatoxin B1 (AFB1 ) accumulation in kernels, which is hazardous for human health due to its carcinogenic activity. In this study, the mechanism used by exogenous β-aminobutyric acid (BABA) treatment for attenuating Aspergillus decay, minimizing aflatoxin B1 (AFB1 ) accumulation, and maintaining nutritional quality in fresh-in-hull pistachio kernels, infected by A. flavus during storage at 25 °C for 18 days, was investigated. RESULT Results of an in vivo assay showed that the spore germination and germ tube elongation of A. flavus was repressed by BABA treatment at 7.5 mM. Aspergillus decay accompanied by AFB1 accumulation was also minimized in fresh-in-hull pistachio kernels treated with BABA at 7.5 mM and infected by A. flavus. Fresh-in-hull pistachio kernels, infected by A. flavus, treated with BABA at 7.5 mM, also exhibited higher phenol and flavonoid accumulation and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity accompanied by higher phenylalanine ammonia lyase (PAL) enzyme activity. CONCLUSION Promoting phenylpropanoid pathway activity with higher PAL enzyme activity in fresh-in-hull pistachio kernels treated with BABA may not only reduce Aspergillus decay in kernels by cell wall fortification but also may be favorable for maintaining the kernels' nutritional quality through its effects on ROS scavenging capacity. As oxidative stress, represented by ROS accumulation, is responsible for A. flavus growth and AFB1 accumulation, higher phenol and flavonoid accumulation in fresh-in-hull pistachio kernels treated with BABA may be beneficial for attenuating Aspergillus decay and minimizing AFB1 accumulation. © 2019 Society of Chemical Industry.
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Affiliation(s)
| | - Zisheng Luo
- Key Laboratory for Agro-Products Postharvest Handling of Ministry of Agriculture, Zhejiang Key Laboratory for Agro-Food Processing, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, 310058, China
| | - Roghayeh Aminian-Dehkordi
- Department of Genetics and Plant Breeding, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran
| | - Abbasali Jannatizadeh
- Department of Horticultural Science, Imam Khomeini International University, Qazvin, Iran
| | - Boukaga Farmani
- Department of Food Science and Technology, Ahar Faculty of Agriculture and Natural Resources, University of Tabriz, Ahar, Iran
| | - Mehdi Younessi-Hamzekhanlu
- Department of Forestry and Medicinal Plants, Ahar Faculty of Agriculture and Natural Resources, University of Tabriz, Ahar, Iran
| | - Abdollah Ahmadpour
- Higher Education Center Shahid Bakeri Miyandoab, Urmia University, Urmia, Iran
| | - Farhang Razavi
- Department of Horticulture, Faculty of Agriculture, University of Zanjan, Zanjan, Iran
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28
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Soni P, Gangurde SS, Ortega-Beltran A, Kumar R, Parmar S, Sudini HK, Lei Y, Ni X, Huai D, Fountain JC, Njoroge S, Mahuku G, Radhakrishnan T, Zhuang W, Guo B, Liao B, Singam P, Pandey MK, Bandyopadhyay R, Varshney RK. Functional Biology and Molecular Mechanisms of Host-Pathogen Interactions for Aflatoxin Contamination in Groundnut ( Arachis hypogaea L.) and Maize ( Zea mays L.). Front Microbiol 2020; 11:227. [PMID: 32194520 PMCID: PMC7063101 DOI: 10.3389/fmicb.2020.00227] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 01/30/2020] [Indexed: 12/26/2022] Open
Abstract
Aflatoxins are secondary metabolites produced by soilborne saprophytic fungus Aspergillus flavus and closely related species that infect several agricultural commodities including groundnut and maize. The consumption of contaminated commodities adversely affects the health of humans and livestock. Aflatoxin contamination also causes significant economic and financial losses to producers. Research efforts and significant progress have been made in the past three decades to understand the genetic behavior, molecular mechanisms, as well as the detailed biology of host-pathogen interactions. A range of omics approaches have facilitated better understanding of the resistance mechanisms and identified pathways involved during host-pathogen interactions. Most of such studies were however undertaken in groundnut and maize. Current efforts are geared toward harnessing knowledge on host-pathogen interactions and crop resistant factors that control aflatoxin contamination. This study provides a summary of the recent progress made in enhancing the understanding of the functional biology and molecular mechanisms associated with host-pathogen interactions during aflatoxin contamination in groundnut and maize.
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Affiliation(s)
- Pooja Soni
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sunil S. Gangurde
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rakesh Kumar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Sejal Parmar
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Hari K. Sudini
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | - Yong Lei
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Xinzhi Ni
- Crop Genetics and Breeding Research Unit, United States Department of Agriculture – Agriculture Research Service, Tifton, GA, United States
| | - Dongxin Huai
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Jake C. Fountain
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
| | - Samuel Njoroge
- International Crops Research Institute for the Semi-Arid Tropics, Lilongwe, Malawi
| | - George Mahuku
- International Institute of Tropical Agriculture, Dar es Salaam, Tanzania
| | | | - Weijian Zhuang
- Oil Crops Research Institute, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Baozhu Guo
- Crop Protection and Management Research Unit, United States Department of Agriculture – Agricultural Research Service, Tifton, GA, United States
| | - Boshou Liao
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China
| | - Prashant Singam
- Department of Genetics, Osmania University, Hyderabad, India
| | - Manish K. Pandey
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
| | | | - Rajeev K. Varshney
- International Crops Research Institute for the Semi-Arid Tropics, Hyderabad, India
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29
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The MAP kinase AflSlt2 modulates aflatoxin biosynthesis and peanut infection in the fungus Aspergillus flavus. Int J Food Microbiol 2020; 322:108576. [PMID: 32240921 DOI: 10.1016/j.ijfoodmicro.2020.108576] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/21/2020] [Accepted: 02/29/2020] [Indexed: 12/20/2022]
Abstract
Aflatoxin contamination in food and feed products has been brought into sharp focus over the last few decades in the world. However, there is no effective strategy for solving the problem thus far. Therefore, basic research on the aflatoxin-producer Aspergillus flavus is an urgent need. The vital role of mitogen-activated protein kinases (MAPKs) in signal transduction has been documented in various pathogenic fungi, but their functions in A. flavus have rarely been investigated. Herein, we characterized the detailed function of one of these MAPKs, AflSlt2. Targeted deletion of AflSlt2 gene indicates that this kinase is required for vegetative growth, conidia generation, and sclerotium formation. The analysis of AflSlt2 deletion mutant revealed hypersensitivity to cell wall-damaging chemicals and resistance against hydrogen peroxide. Interestingly, the ability of the ΔAflSlt2 mutant to generate aflatoxins in medium was significantly increased compared to wild type. However, a pathogenicity assay indicated that the ΔAflSlt2 mutant was deficient in peanut infection. Site-directed mutation study uncovered that the function of AflSlt2 was dependent on the phosphorylated residues (Thr-186 and Tyr-188) within the activation loop and the phosphotransfer residue (Lys-52) within the subdomain II. Interestingly, an autophosphorylation mutant of AflSlt2 (AflSlt2R66S) displayed wild type-like phenotypes. Bringing these observations together, we propose that Slt2-MAPK pathway is involved in development, stress response, aflatoxin biosynthesis, and pathogenicity in A. flavus. This study may be useful to unveil the regulation mechanism of aflatoxin biosynthesis and provide strategy to control A. flavus contamination.
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Mesnage R, Oestreicher N, Poirier F, Nicolas V, Boursier C, Vélot C. Transcriptome profiling of the fungus Aspergillus nidulans exposed to a commercial glyphosate-based herbicide under conditions of apparent herbicide tolerance. ENVIRONMENTAL RESEARCH 2020; 182:109116. [PMID: 32069763 DOI: 10.1016/j.envres.2020.109116] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/18/2019] [Accepted: 01/02/2020] [Indexed: 05/20/2023]
Abstract
Glyphosate-based herbicides, such as Roundup®, are the most widely used non-selective, broad-spectrum herbicides. The release of these compounds in large amounts into the environment is susceptible to affect soil quality and health, especially because of the non-target effects on a large range of organisms including soil microorganisms. The soil filamentous fungus Aspergillus nidulans, a well-characterized experimental model organism that can be used as a bio-indicator for agricultural soil health, has been previously shown to be highly affected by Roundup GT Plus (R450: 450 g/L of glyphosate) at concentrations far below recommended agricultural application rate, including at a dose that does not cause any macroscopic effect. In this study, we determined alterations in the transcriptome of A. nidulans when exposed to R450 at a dose corresponding to the no-observed-adverse-effect level (NOAEL) for macroscopic parameters. A total of 1816 distinct genes had their expression altered. The most affected biological functions were protein synthesis, amino acids and secondary metabolisms, stress response, as well as detoxification pathways through cytochromes P450, glutathione-S-transferases, and ABC transporters. These results partly explain the molecular mechanisms underlying alterations in growth parameters detected at higher concentrations for this ascomycete fungus. In conclusion, our results highlight molecular disturbances in a soil fungus under conditions of apparent tolerance to the herbicide, and thus confirm the need to question the principle of "substantial equivalence" when applied to plants made tolerant to herbicides.
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Affiliation(s)
- Robin Mesnage
- Gene Expression and Therapy Group, King's College London, Faculty of Life Sciences & Medicine, Department of Medical and Molecular Genetics, 8th Floor, Tower Wing, Guy's Hospital, Great Maze Pond, London, SE1 9RT, United Kingdom; CRIIGEN, 42 Rue de Lisbonne, 75008, Paris, France.
| | - Nathalie Oestreicher
- Equipe VEAC, Université Paris-Sud, Faculté des Sciences, Bât. 350, Avenue Jean Perrin, 91405, Orsay, France; Pôle Risques MRSH-CNRS, EA2608, Université de Caen, Esplanade de la Paix, 14032, Caen, France.
| | - Florence Poirier
- Université Paris 13, UFR SMBH, Plateforme PPUP13, 1 Rue de Chablis, 93017, Bobigny Cedex, France.
| | - Valérie Nicolas
- UMS-IPSIT, US31 Inserm-UMS3679 CNRS, Plateformes Trans-Prot et d'Imagerie Cellulaire, Université Paris-Sud, Faculté de Pharmacie, Tour E1, 5 Rue Jean-Baptiste Clément, 92296, Châtenay-Malabry, France.
| | - Céline Boursier
- UMS-IPSIT, US31 Inserm-UMS3679 CNRS, Plateformes Trans-Prot et d'Imagerie Cellulaire, Université Paris-Sud, Faculté de Pharmacie, Tour E1, 5 Rue Jean-Baptiste Clément, 92296, Châtenay-Malabry, France.
| | - Christian Vélot
- CRIIGEN, 42 Rue de Lisbonne, 75008, Paris, France; Equipe VEAC, Université Paris-Sud, Faculté des Sciences, Bât. 350, Avenue Jean Perrin, 91405, Orsay, France; Pôle Risques MRSH-CNRS, EA2608, Université de Caen, Esplanade de la Paix, 14032, Caen, France.
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Pfliegler WP, Pócsi I, Győri Z, Pusztahelyi T. The Aspergilli and Their Mycotoxins: Metabolic Interactions With Plants and the Soil Biota. Front Microbiol 2020; 10:2921. [PMID: 32117074 PMCID: PMC7029702 DOI: 10.3389/fmicb.2019.02921] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 12/04/2019] [Indexed: 01/06/2023] Open
Abstract
Species of the highly diverse fungal genus Aspergillus are well-known agricultural pests, and, most importantly, producers of various mycotoxins threatening food safety worldwide. Mycotoxins are studied predominantly from the perspectives of human and livestock health. Meanwhile, their roles are far less known in nature. However, to understand the factors behind mycotoxin production, the roles of the toxins of Aspergilli must be understood from a complex ecological perspective, taking mold-plant, mold-microbe, and mold-animal interactions into account. The Aspergilli may switch between saprophytic and pathogenic lifestyles, and the production of secondary metabolites, such as mycotoxins, may vary according to these fungal ways of life. Recent studies highlighted the complex ecological network of soil microbiotas determining the niches that Aspergilli can fill in. Interactions with the soil microbiota and soil macro-organisms determine the role of secondary metabolite production to a great extent. While, upon infection of plants, metabolic communication including fungal secondary metabolites like aflatoxins, gliotoxin, patulin, cyclopiazonic acid, and ochratoxin, influences the fate of both the invader and the host. In this review, the role of mycotoxin producing Aspergillus species and their interactions in the ecosystem are discussed. We intend to highlight the complexity of the roles of the main toxic secondary metabolites as well as their fate in natural environments and agriculture, a field that still has important knowledge gaps.
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Affiliation(s)
- Walter P. Pfliegler
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, Debrecen, Hungary
| | - Zoltán Győri
- Institute of Nutrition, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
| | - Tünde Pusztahelyi
- Central Laboratory of Agricultural and Food Products, Faculty of Agricultural and Food Sciences and Environmental Management, University of Debrecen, Debrecen, Hungary
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Kövesi B, Cserháti M, Erdélyi M, Zándoki E, Mézes M, Balogh K. Lack of Dose- and Time-Dependent Effects of Aflatoxin B1 on Gene Expression and Enzymes Associated with Lipid Peroxidation and the Glutathione Redox System in Chicken. Toxins (Basel) 2020; 12:toxins12020084. [PMID: 31991868 PMCID: PMC7076774 DOI: 10.3390/toxins12020084] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 11/16/2022] Open
Abstract
Effects of aflatoxin B1 (AFB1) on lipid peroxidation and glutathione system were investigated in chicken liver. In a three-week feeding trial, different doses (<1.0 μg/kg (control diet), 17.0 µg (diet A1), 92.0 µg (diet A2), and 182.0 µg (diet A3) AFB1 kg/feed) were used. Markers of lipid peroxidation, conjugated dienes and trienes showed higher values in A3, while amounts of thiobarbituric acid reactive substances were increased in the A1 group at day 21. Glutathione content was lower at day 14 in Group A2. Glutathione peroxidase 4 activity was increased at days 7 and 21 in the A3 group but reduced in the A2 and A3 groups at day 14. The GPX4 gene was downregulated at day 7 in the A2 group, but overregulated at days 14 and 21, and at day 14 in the A3 group. GSS was downregulated at day 14 in the A1 group but overregulated at day 21 in A1 and A2 groups. GSR was downregulated at days 7 and 21 in all treatment groups, but on day 14, induction was observed in the A3 group. The results indicated that AFB1 did not induce dose- or time-dependent effects on the glutathione redox system and its encoding genes at the dose range used, which means that oxidative stress is not the primary effect of AFB1 toxicity.
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Affiliation(s)
- Benjámin Kövesi
- Department of Nutrition, Szent István University, H-2103 Gödöllő, Hungary; (B.K.); (M.E.); (K.B.)
| | - Mátyás Cserháti
- Department of Environmental Safety and Ecotoxicology, Szent István University, H-2103 Gödöllő, Hungary;
| | - Márta Erdélyi
- Department of Nutrition, Szent István University, H-2103 Gödöllő, Hungary; (B.K.); (M.E.); (K.B.)
| | - Erika Zándoki
- MTA-KE-SZIE Mycotoxins in the Food Chain Research Group, Kaposvár University, H-7400 Kaposvár, Hungary;
| | - Miklós Mézes
- Department of Nutrition, Szent István University, H-2103 Gödöllő, Hungary; (B.K.); (M.E.); (K.B.)
- MTA-KE-SZIE Mycotoxins in the Food Chain Research Group, Kaposvár University, H-7400 Kaposvár, Hungary;
- Correspondence:
| | - Krisztián Balogh
- Department of Nutrition, Szent István University, H-2103 Gödöllő, Hungary; (B.K.); (M.E.); (K.B.)
- MTA-KE-SZIE Mycotoxins in the Food Chain Research Group, Kaposvár University, H-7400 Kaposvár, Hungary;
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Zhu J, Wu F, Yue S, Chen C, Song S, Wang H, Zhao M. Functions of reactive oxygen species in apoptosis and ganoderic acid biosynthesis in Ganoderma lucidum. FEMS Microbiol Lett 2019; 366:5714084. [PMID: 31967638 DOI: 10.1093/femsle/fnaa015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 01/21/2020] [Indexed: 12/26/2022] Open
Abstract
Ganoderma lucidum is a medicinal fungus that is widely used in traditional medicine. Fungal PacC is recognized as an important transcription factor that functions during adaptation to environmental pH, fungal development and secondary metabolism. Previous studies have revealed that GlPacC plays important roles in mycelial growth, fruiting body development and ganoderic acid (GA) biosynthesis. In this study, using a terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay, we found that the apoptosis level was increased when PacC was silenced. The transcript and activity levels of caspase-like proteins were significantly increased in the PacC-silenced (PacCi) strains compared with the control strains. Silencing PacC also resulted in an increased reactive oxygen species (ROS) levels (∼2-fold) and decreased activity levels of enzymes involved in the antioxidant system. Further, we found that the intracellular ROS levels contributed to apoptosis and GA biosynthesis. Adding N-acetyl-cysteine and vitamin C decreased intracellular ROS and resulted in the inhibition of apoptosis in the PacCi strains. Additionally, the GA biosynthesis was different between the control strains and the PacCi strains after intracellular ROS was eliminated. Taken together, the findings showed that silencing PacC can result in an intracellular ROS burst, which increases cell apoptosis and GA biosynthesis levels. Our study provides novel insight into the functions of PacC in filamentous fungi.
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Affiliation(s)
- Jing Zhu
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Fengli Wu
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Sining Yue
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Chen Chen
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Shuqi Song
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Hui Wang
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
| | - Mingwen Zhao
- Key Laboratory of Edible Mushroom Processing, Ministry of Agriculture; Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, Jiangsu, P.R. China
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Fountain JC, Yang L, Pandey MK, Bajaj P, Alexander D, Chen S, Kemerait RC, Varshney RK, Guo B. Carbohydrate, glutathione, and polyamine metabolism are central to Aspergillus flavus oxidative stress responses over time. BMC Microbiol 2019; 19:209. [PMID: 31488075 PMCID: PMC6727485 DOI: 10.1186/s12866-019-1580-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/25/2019] [Indexed: 01/08/2023] Open
Abstract
Background The primary and secondary metabolites of fungi are critical for adaptation to environmental stresses, host pathogenicity, competition with other microbes, and reproductive fitness. Drought-derived reactive oxygen species (ROS) have been shown to stimulate aflatoxin production and regulate in Aspergillus flavus, and may function in signaling with host plants. Here, we have performed global, untargeted metabolomics to better understand the role of aflatoxin production in oxidative stress responses, and also explore isolate-specific oxidative stress responses over time. Results Two field isolates of A. flavus, AF13 and NRRL3357, possessing high and moderate aflatoxin production, respectively, were cultured in medium with and without supplementation with 15 mM H2O2, and mycelia were collected following 4 and 7 days in culture for global metabolomics. Overall, 389 compounds were described in the analysis which encompassed 9 biological super-pathways and 47 sub-pathways. These metabolites were examined for differential accumulation. Significant differences were observed in both isolates in response to oxidative stress and when comparing sampling time points. Conclusions The moderately high aflatoxin-producing isolate, NRRL3357, showed extensive stimulation of antioxidant mechanisms and pathways including polyamines metabolism, glutathione metabolism, TCA cycle, and lipid metabolism while the highly aflatoxigenic isolate, AF13, showed a less vigorous response to stress. Carbohydrate pathway levels also imply that carbohydrate repression and starvation may influence metabolite accumulation at the later timepoint. Higher conidial oxidative stress tolerance and antioxidant capacity in AF13 compared to NRRL3357, inferred from their metabolomic profiles and growth curves over time, may be connected to aflatoxin production capability and aflatoxin-related antioxidant accumulation. The coincidence of several of the detected metabolites in H2O2-stressed A. flavus and drought-stressed hosts also suggests their potential role in the interaction between these organisms and their use as markers/targets to enhance host resistance through biomarker selection or genetic engineering. Electronic supplementary material The online version of this article (10.1186/s12866-019-1580-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jake C Fountain
- USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA, 31793, USA.,Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Liming Yang
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA.,College of Biology and Environmental Science, Nanjing Forestry University, Nanjing, 210037, China
| | - Manish K Pandey
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, 502324, India
| | - Prasad Bajaj
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, 502324, India
| | | | - Sixue Chen
- Department of Biology, Genetics Institute, and Plant Molecular & Cellular Biology Program, University of Florida, Gainesville, FL, 32611, USA
| | - Robert C Kemerait
- Department of Plant Pathology, University of Georgia, Tifton, GA, 31793, USA
| | - Rajeev K Varshney
- International Crop Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, Telangana, 502324, India
| | - Baozhu Guo
- USDA-ARS, Crop Protection and Management Research Unit, Tifton, GA, 31793, USA.
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Zhi QQ, He L, Li JY, Li J, Wang ZL, He GY, He ZM. The Kinetochore Protein Spc105, a Novel Interaction Partner of LaeA, Regulates Development and Secondary Metabolism in Aspergillus flavus. Front Microbiol 2019; 10:1881. [PMID: 31456789 PMCID: PMC6700525 DOI: 10.3389/fmicb.2019.01881] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/30/2019] [Indexed: 01/04/2023] Open
Abstract
Nuclear protein LaeA is known as the global regulator of secondary metabolism in Aspergillus. LaeA connects with VeA and VelB to form a heterotrimeric complex, which coordinates fungal development and secondary metabolism. Here, we describe a new interaction partner of LaeA, the kinetochore protein Spc105, from the aflatoxin-producing fungus Aspergillus flavus. We showed that in addition to involvement in nuclear division, Spc105 is required for normal conidiophore development and sclerotia production of A. flavus. Moreover, Spc105 positively regulates the production of secondary metabolites such as aflatoxin and kojic acid, and negatively regulates the production of cyclopiazonic acid. Transcriptome analysis of the Δspc105 strain revealed that 23 backbone genes were differentially expressed, corresponding to 19 of the predicted 56 secondary metabolite gene clusters, suggesting a broad regulatory role of Spc105 in secondary metabolism. Notably, the reduced expression of laeA in our transcriptome data led to the discovery of the correlation between Spc105 and LaeA, and double mutant analysis indicated a functional interdependence between Spc105 and LaeA. Further, in vitro and in vivo protein interaction assays revealed that Spc105 interacts directly with the S-adenosylmethionine (SAM)-binding domain of LaeA, and that the leucine zipper motif in Spc105 is required for this interaction. The Spc105-LaeA interaction identified in our study indicates a cooperative interplay of distinct regulators in A. flavus, providing new insights into fungal secondary metabolism regulation networks.
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Affiliation(s)
- Qing-Qing Zhi
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Lei He
- Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, China
| | - Jie-Ying Li
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jing Li
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhen-Long Wang
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Guang-Yao He
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhu-Mei He
- The Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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Shen L, Porée FH, Gaslonde T, Lalucque H, Chapeland-Leclerc F, Ruprich-Robert G. Functional characterization of the sterigmatocystin secondary metabolite gene cluster in the filamentous fungus Podospora anserina: involvement in oxidative stress response, sexual development, pigmentation and interspecific competitions. Environ Microbiol 2019; 21:3011-3026. [PMID: 31136075 DOI: 10.1111/1462-2920.14698] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 12/13/2022]
Abstract
Filamentous fungi are known as prolific untapped reservoirs of diverse secondary metabolites, where genes required for their synthesis are organized in clusters. The bioactive properties of these compounds are closely related to their functions in fungal biology, which are not well understood. In this study, we focused on the Podospora anserina gene cluster responsible for the biosynthesis of sterigmatocystin (ST). Deletion of the PaStcA gene encoding the polyketide synthase and overexpression (OE) of the PaAflR gene encoding the ST-specific transcription factor in P. anserina were performed. We showed that growth of PaStcAΔ was inhibited in the presence of methylglyoxal, while OE-PaAflR showed a little inhibition, indicating that ST production may enhance oxidative stress tolerance in P. anserina. We also showed that the OE-PaAflR strain displayed an overpigmented thallus mediated by the melanin pathway. Overexpression of PaAflR also led to sterility. Interspecific confrontation assays showed that ST-overexpressed strains produced a high level of peroxides and possessed a higher competitiveness against other fungi. Comparative metabolite profiling demonstrated that PaStcAΔ strain was unable to produce ST, while OE-PaAflR displayed a ST overproduction. This study contributes to a better understanding of ST in P. anserina, especially with regard to its involvement in fungal physiology.
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Affiliation(s)
- Ling Shen
- Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université de Paris, Université Paris Diderot, UMR 8236, 75205, Paris, France
| | - François-Hugues Porée
- Laboratoire de Pharmacognosie, Faculté de Pharmacie de Paris, Université de Paris, Université Paris Descartes, UMR CNRS CITCOM 8038, 75006, Paris, France
| | - Thomas Gaslonde
- Laboratoire de Pharmacognosie, Faculté de Pharmacie de Paris, Université de Paris, Université Paris Descartes, UMR CNRS CITCOM 8038, 75006, Paris, France
| | - Hervé Lalucque
- Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université de Paris, Université Paris Diderot, UMR 8236, 75205, Paris, France
| | - Florence Chapeland-Leclerc
- Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université de Paris, Université Paris Descartes, UMR 8236, 75205, Paris, France
| | - Gwenaël Ruprich-Robert
- Laboratoire Interdisciplinaire des Energies de Demain (LIED), Université de Paris, Université Paris Descartes, UMR 8236, 75205, Paris, France
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Adegbeye MJ, Elghandour MMMY, Barbabosa-Pliego A, Monroy JC, Mellado M, Ravi Kanth Reddy P, Salem AZM. Nanoparticles in Equine Nutrition: Mechanism of Action and Application as Feed Additives. J Equine Vet Sci 2019; 78:29-37. [PMID: 31203981 DOI: 10.1016/j.jevs.2019.04.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 03/31/2019] [Accepted: 04/01/2019] [Indexed: 12/29/2022]
Abstract
Several concerns exist regarding horse rearing such as environmental pollution, antibiotics resistance, digestive disorders, mycotoxins contamination of animal feed, gut health management, and improvement of feed efficiency. Nanoparticles have the potential to address these issues and thus could be used as feed additive. Citrate reduces and stabilizes gold nanoparticles, alongside biosynthesized silver nanoparticles have the potential to prolong and improve digestive enzyme activity, which would enhance starch digestibility in the stomach. Zinc oxide and selenium nanoparticles could be used to improve feed digestibility and volatile fatty acids production. Magnesium oxide, silver, and copper nanoparticles exhibit strong antimicrobial activity against gram-positive and gram-negative microbes and weaken the biofilm formation of the microbial community. Calcium, zinc, and silver nanoparticles could be used to prevent periodontal disease in horses. In addition, silver nanoparticles may be applied as antifasciolitics and potentially against other gastrointestinal parasites. Environmental concern of equines could be addressed by using cerium oxide, silver, and cobalt nanoparticles to reduce methane emission and zinc oxide could help to reduce fecal mineral output. Fullerol C60[OH]24, a honey-derived silver nanoparticle and zinc oxide nanoparticles exhibit attractive antibacterial properties because of increased specific surface area as the reduced particle enhance unit surface reactivity. Gut health management of equines could be solved with nanoparticles because of the ability of ferrous oxide and copper nanoparticles to improve microbial growth, whereas zinc oxide improves villus height, crypt depth, and villous surface area. It is required to explore in depth the beneficial effects of these nanoparticles as a novel area in the equine industry's both in vitro and in vivo before recommendation to equine owners.
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Affiliation(s)
- Moyosore J Adegbeye
- Department of Animal Science, College of Agriculture, Joseph Ayo Babalola University, Ilesha, Nigeria
| | - Mona M M Y Elghandour
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, México
| | | | - José Cedillo Monroy
- Centro Universitario UAEM-Temascaltepec, Universidad Autónoma del Estado de México, México
| | - Miguel Mellado
- Departamento de Nutrición Animal, Universidad Autónoma de Antonio Narro, Saltillo, México
| | | | - Abdelfattah Z M Salem
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, México.
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Zhen Z, Xiong X, Liu Y, Zhang J, Wang S, Li L, Gao M. NaCl Inhibits Citrinin and Stimulates Monascus Pigments and Monacolin K Production. Toxins (Basel) 2019; 11:toxins11020118. [PMID: 30769930 PMCID: PMC6409629 DOI: 10.3390/toxins11020118] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 02/08/2019] [Accepted: 02/13/2019] [Indexed: 12/23/2022] Open
Abstract
Applications of beneficial secondary metabolites produced by Monascus purpureus (M. purpureus) could be greatly limited for citrinin, a kidney toxin. The link of NaCl with cell growth and secondary metabolites in M. purpureus was analyzed with supplementations of different concentrations of NaCl in medium. The content of citrinin was reduced by 48.0% but the yellow, orange, red pigments and monacolin K productions were enhanced by 1.7, 1.4, 1.4 and 1.4 times, respectively, compared with those in the control using NaCl at 0.02 M at the 10th day of cultivation. NaCl didn’t affect the cell growth of M. purpureus. This was verified through the transcriptional up-regulation of citrinin synthesis genes (pksCT and ctnA) and the down-regulation of the Monascus pigments (MPs) synthesis genes (pksPT and pigR). Moreover, the reactive oxygen species (ROS) levels were promoted by NaCl at the 2nd day of cultivation, and then inhibited remarkably with the extension of fermentation time. Meanwhile, the activities of superoxide dismutase (SOD) and catalase (CAT), and the contents of total glutathione (T-GSH) were significantly enhanced in the middle and late stages of cultivation. The inhibition effect on colony size and the growth of aerial mycelia was more obvious with an increased NaCl concentration. Acid and alkaline phosphatase (ACP and AKP) activities dramatically increased in NaCl treatments. NaCl could participate in secondary metabolites synthesis and cell growth in M. purpureus.
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Affiliation(s)
- Zhixin Zhen
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Xiaoqian Xiong
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Yingbao Liu
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Jialan Zhang
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Shaojin Wang
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Li Li
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
| | - Mengxiang Gao
- College of Life Science, Yangtze University, Jingzhou 434025, Hubei, China.
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40
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Fullerol C 60(OH) 24 nanoparticles modulate aflatoxin B 1 biosynthesis in Aspergillus flavus. Sci Rep 2018; 8:12855. [PMID: 30150708 PMCID: PMC6110770 DOI: 10.1038/s41598-018-31305-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/14/2018] [Indexed: 12/25/2022] Open
Abstract
The water soluble fullerene C60 daughter product - fullerols C60(OH)24 (FNP) possesses a great potential of modifying secondary metabolites biosynthesis. In order to clarify the extent of interaction, the impact of FNP (10, 100 and 1000 ng mL-1) on aflatoxin production and the available precursors of biosynthesis pathway from Aspergillus flavus NRRL 3251 was determined, in both the mycelia and yeast extract sucrose (YES) medium, during a 168-hour growth period at 29 °C in the dark. The FNP of 8 nm in diameter, and with a zeta potential of -33 mV affected mycelial growth at 1000 ng mL-1 while conidia production was slightly affected at 10 ng mL-1. The FNP effect on aflatoxin and it biosynthetic precursors was concentration dependent and alteration of the sterigmatocystin (ST) export from the cell was observed. Most of the monitored aflatoxin precursors, except norsolorinic acid, were detected in both mycelia and YES medium. However, observed precursor concentrations were much higher in mycelia, with exception of ST. The study shows the loss of FNP antioxidative effect after 120 hours of growth, and strong concentration dependent aflatoxigenic effect after that time. Thus, this data is relevant to guide future considerations on FNP-fungal interactions in the environments and on risk assessment.
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Analysis of the Relationship between Alternative Respiration and Sterigmatocystin Formation in Aspergillus nidulans. Toxins (Basel) 2018; 10:toxins10040168. [PMID: 29677138 PMCID: PMC5923334 DOI: 10.3390/toxins10040168] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 04/16/2018] [Accepted: 04/17/2018] [Indexed: 01/14/2023] Open
Abstract
Aspergillus nidulans has one gene for alternative oxidase (EC 1.10.3.11). To investigate the relationship between this mitochondrial terminal oxidase and the formation of the mycotoxin sterigmatocystin, the encoding aodA gene was both deleted and overexpressed. Relative to the wild-type, the cyanide-resistant fraction of respiration in the late stationary stage—when sterigmatocystin production occurs—doubled in the overexpressing mutant carrying three aodA gene copies, but decreased to 10% in the deletant. Essentially identical results were obtained regardless whether the cultures were illuminated or protected from light. In contrast, sterigmatocystin yield in the aodA deletant was about half of that in the control when grown in the dark, while aodA overexpression resulted in up to 70% more sterigmatocystin formed, the yield increasing with alternative oxidase activity. Results were quite different when cultures were illuminated: under those conditions, sterigmatocystin volumetric yields were considerably lower, and statistically unvarying, regardless of the presence, absence, or the copy number of aodA. We conclude that the copy number of aodA, and hence, the balance between alternative- and cytochrome C-mediated respiration, appears to correlate with sterigmatocystin production in A. nidulans, albeit only in the absence of light.
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Aspergillus flavus Secondary Metabolites: More than Just Aflatoxins. Food Saf (Tokyo) 2018; 6:7-32. [PMID: 32231944 DOI: 10.14252/foodsafetyfscj.2017024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 03/09/2018] [Indexed: 11/21/2022] Open
Abstract
Aspergillus flavus is best known for producing the family of potent carcinogenic secondary metabolites known as aflatoxins. However, this opportunistic plant and animal pathogen also produces numerous other secondary metabolites, many of which have also been shown to be toxic. While about forty of these secondary metabolites have been identified from A. flavus cultures, analysis of the genome has predicted the existence of at least 56 secondary metabolite gene clusters. Many of these gene clusters are not expressed during growth of the fungus on standard laboratory media. This presents researchers with a major challenge of devising novel strategies to manipulate the fungus and its genome so as to activate secondary metabolite gene expression and allow identification of associated cluster metabolites. In this review, we discuss the genetic, biochemical and bioinformatic methods that are being used to identify previously uncharacterized secondary metabolite gene clusters and their associated metabolites. It is important to identify as many of these compounds as possible to determine their bioactivity with respect to fungal development, survival, virulence and especially with respect to any potential synergistic toxic effects with aflatoxin.
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Insight into Genes Regulating Postharvest Aflatoxin Contamination of Tetraploid Peanut from Transcriptional Profiling. Genetics 2018; 209:143-156. [PMID: 29545468 DOI: 10.1534/genetics.118.300478] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Accepted: 03/07/2018] [Indexed: 11/18/2022] Open
Abstract
Postharvest aflatoxin contamination is a challenging issue that affects peanut quality. Aflatoxin is produced by fungi belonging to the Aspergilli group, and is known as an acutely toxic, carcinogenic, and immune-suppressing class of mycotoxins. Evidence for several host genetic factors that may impact aflatoxin contamination has been reported, e.g., genes for lipoxygenase (PnLOX1 and PnLOX2/PnLOX3 that showed either positive or negative regulation with Aspergillus infection), reactive oxygen species, and WRKY (highly associated with or differentially expressed upon infection of maize with Aspergillus flavus); however, their roles remain unclear. Therefore, we conducted an RNA-sequencing experiment to differentiate gene response to the infection by A. flavus between resistant (ICG 1471) and susceptible (Florida-07) cultivated peanut genotypes. The gene expression profiling analysis was designed to reveal differentially expressed genes in response to the infection (infected vs. mock-treated seeds). In addition, the differential expression of the fungal genes was profiled. The study revealed the complexity of the interaction between the fungus and peanut seeds as the expression of a large number of genes was altered, including some in the process of plant defense to aflatoxin accumulation. Analysis of the experimental data with "keggseq," a novel designed tool for Kyoto Encyclopedia of Genes and Genomes enrichment analysis, showed the importance of α-linolenic acid metabolism, protein processing in the endoplasmic reticulum, spliceosome, and carbon fixation and metabolism pathways in conditioning resistance to aflatoxin accumulation. In addition, coexpression network analysis was carried out to reveal the correlation of gene expression among peanut and fungal genes. The results showed the importance of WRKY, toll/Interleukin1 receptor-nucleotide binding site leucine-rich repeat (TIR-NBS-LRR), ethylene, and heat shock proteins in the resistance mechanism.
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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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Yang L, Fountain JC, Ji P, Ni X, Chen S, Lee RD, Kemerait RC, Guo B. Deciphering drought-induced metabolic responses and regulation in developing maize kernels. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:1616-1628. [PMID: 29431900 PMCID: PMC6097124 DOI: 10.1111/pbi.12899] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/31/2018] [Accepted: 02/03/2018] [Indexed: 05/07/2023]
Abstract
Drought stress conditions decrease maize growth and yield, and aggravate preharvest aflatoxin contamination. While several studies have been performed on mature kernels responding to drought stress, the metabolic profiles of developing kernels are not as well characterized, particularly in germplasm with contrasting resistance to both drought and mycotoxin contamination. Here, following screening for drought tolerance, a drought-sensitive line, B73, and a drought-tolerant line, Lo964, were selected and stressed beginning at 14 days after pollination. Developing kernels were sampled 7 and 14 days after drought induction (DAI) from both stressed and irrigated plants. Comparative biochemical and metabolomic analyses profiled 409 differentially accumulated metabolites. Multivariate statistics and pathway analyses showed that drought stress induced an accumulation of simple sugars and polyunsaturated fatty acids and a decrease in amines, polyamines and dipeptides in B73. Conversely, sphingolipid, sterol, phenylpropanoid and dipeptide metabolites accumulated in Lo964 under drought stress. Drought stress also resulted in the greater accumulation of reactive oxygen species (ROS) and aflatoxin in kernels of B73 in comparison with Lo964 implying a correlation in their production. Overall, field drought treatments disordered a cascade of normal metabolic programming during development of maize kernels and subsequently caused oxidative stress. The glutathione and urea cycles along with the metabolism of carbohydrates and lipids for osmoprotection, membrane maintenance and antioxidant protection were central among the drought stress responses observed in developing kernels. These results also provide novel targets to enhance host drought tolerance and disease resistance through the use of biotechnologies such as transgenics and genome editing.
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Affiliation(s)
- Liming Yang
- USDA‐ARS, Crop Protection and Management Research UnitTiftonGAUSA
- Department of Plant PathologyUniversity of GeorgiaTiftonGAUSA
- College of Biology and the EnvironmentNanjing Forestry UniversityNanjingJiangsuChina
| | - Jake C. Fountain
- USDA‐ARS, Crop Protection and Management Research UnitTiftonGAUSA
- Department of Plant PathologyUniversity of GeorgiaTiftonGAUSA
| | - Pingsheng Ji
- Department of Plant PathologyUniversity of GeorgiaTiftonGAUSA
| | - Xinzhi Ni
- USDA‐ARS, Crop Genetics and Breeding Research UnitTiftonGAUSA
| | - Sixue Chen
- Department of Biology, Genetics Institute, and Plant Molecular & Cellular Biology ProgramUniversity of FloridaGainesvilleFLUSA
| | - Robert D. Lee
- Department of Crop and Soil SciencesUniversity of GeorgiaTiftonGAUSA
| | | | - Baozhu Guo
- USDA‐ARS, Crop Protection and Management Research UnitTiftonGAUSA
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Chen C, Li Q, Wang Q, Lu D, Zhang H, Wang J, Fu R. Transcriptional profiling provides new insights into the role of nitric oxide in enhancing Ganoderma oregonense resistance to heat stress. Sci Rep 2017; 7:15694. [PMID: 29146915 PMCID: PMC5691203 DOI: 10.1038/s41598-017-15340-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 10/26/2017] [Indexed: 12/18/2022] Open
Abstract
Ganoderma is well known for its use in traditional Chinese medicine and is widely cultivated in China, Korea, and Japan. Increased temperatures associated with global warming are negatively influencing the growth and development of Ganoderma. Nitric oxide is reported to play an important role in alleviating fungal heat stress (HS). However, the transcriptional profiling of Ganoderma oregonense in response to HS, as well as the transcriptional response regulated by NO to cope with HS has not been reported. We used RNA-Seq technology to generate large-scale transcriptome data from G. oregonense mycelia subjected to HS (32 °C) and exposed to concentrations of exogenous NO. The results showed that heat shock proteins (HSPs), "probable stress-induced proteins", and unigenes involved in "D-amino-acid oxidase activity" and "oxidoreductase activity" were significantly up-regulated in G. oregonense subjected to HS (P < 0.05). The significantly up-regulated HSPs, "monooxygenases", "alcohol dehydrogenase", and "FAD/NAD(P)-binding domain-containing proteins" (P < 0.05) regulated by exogenous NO may play important roles in the enhanced HS tolerance of G. oregonense. These results provide insights into the transcriptional response of G. oregonense to HS and the mechanism by which NO enhances the HS tolerance of fungi at the gene expression level.
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Affiliation(s)
- Cheng Chen
- Institute of plant protection, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, P.R. China
| | - Qiang Li
- Biotechnology and Nuclear Technology Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610061, Sichuan, P.R. China.,Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, Sichuan, P.R. China
| | - Qiangfeng Wang
- Biotechnology and Nuclear Technology Research Institute, Sichuan Academy of Agricultural Sciences, Chengdu, 610061, Sichuan, P.R. China
| | - Daihua Lu
- Institute of plant protection, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, P.R. China
| | - Hong Zhang
- Institute of plant protection, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, P.R. China. .,Sichuan Academy of Agricultural Sciences, 20 # Jingjusi Rd, Chengdu, 610066, Sichuan, China.
| | - Jian Wang
- Institute of plant protection, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, P.R. China
| | - Rongtao Fu
- Institute of plant protection, Sichuan Academy of Agricultural Sciences, Chengdu, 610066, P.R. China
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