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Zhou Z, Liu J, Zhang J, Yan H, Yi T, Shim WB. Characterization of Fusarium verticillioides Med1 LxxLL Motif Involved in Fumonisin Biosynthesis. Toxins (Basel) 2023; 15:652. [PMID: 37999515 PMCID: PMC10675092 DOI: 10.3390/toxins15110652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/31/2023] [Accepted: 11/10/2023] [Indexed: 11/25/2023] Open
Abstract
The Med1 transcriptional coactivator is a crucial component of the Mediator middle complex, which regulates the expression of specific genes involved in cell development, differentiation, reproduction, and homeostasis. The Med1 LxxLL motif, a five-amino-acid peptide sequence, is essential for Med1-mediated gene expression. Our previous study revealed that the disruption of the Med1 subunit leads to a significant increase in fumonisin B1 (FB1) production in the maize pathogen Fusarium verticillioides. However, our understanding of how Med1 regulates FB1 biosynthesis in F. verticillioides, particularly through the Med1 LxxLL motifs, remains limited. To characterize the role of LxxLL motifs, we generated a series of Med1 LxxLL deletion and amino acid substitution mutants. These mutants exhibited impaired mycelial growth and conidia germination while demonstrating enhanced conidia production and virulence. Similar to the Med1 deletion mutant, Med1 LxxLL motif mutants also exhibited increased FB1 biosynthesis in F. verticillioides. Proteomic profiling revealed that the Med1 LxxLL motif regulated the biosynthesis of several key substances that affected FB1 production, including starch and carotenoid. Subsequent studies demonstrated that the production of amylopectin, which is strongly linked to FB1 biosynthesis, was significantly increased in Med1 LxxLL motif mutants. In addition, the disruption of carotenoid metabolic genes decreased carotenoid content, thus stimulating FB1 biosynthesis in F. verticillioides. Taken together, our results provide valuable insights into how the Med1 LxxLL motif regulates FB1 biosynthesis in the mycotoxigenic fungus F. verticillioides.
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Affiliation(s)
- Zehua Zhou
- Hunan Provincial Key Laboratory for Biology and Control of Plant Pests, Hunan Agricultural University, Changsha 410128, China; (Z.Z.); (J.L.)
| | - Jie Liu
- Hunan Provincial Key Laboratory for Biology and Control of Plant Pests, Hunan Agricultural University, Changsha 410128, China; (Z.Z.); (J.L.)
| | - Jie Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China;
| | - Huijuan Yan
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94143, USA;
| | - Tuyong Yi
- Hunan Provincial Key Laboratory for Biology and Control of Plant Pests, Hunan Agricultural University, Changsha 410128, China; (Z.Z.); (J.L.)
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843, USA
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Sherif M, Kirsch N, Splivallo R, Pfohl K, Karlovsky P. The Role of Mycotoxins in Interactions between Fusarium graminearum and F. verticillioides Growing in Saprophytic Cultures and Co-Infecting Maize Plants. Toxins (Basel) 2023; 15:575. [PMID: 37756001 PMCID: PMC10538043 DOI: 10.3390/toxins15090575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 09/10/2023] [Accepted: 09/15/2023] [Indexed: 09/28/2023] Open
Abstract
Fusarium graminearum (FG) and Fusarium verticillioides (FV) co-occur in infected plants and plant residues. In maize ears, the growth of FV is stimulated while FG is suppressed. To elucidate the role of mycotoxins in these effects, we used FG mutants with disrupted synthesis of nivalenol (NIV) and deoxynivalenol (DON) and a FV mutant with disrupted synthesis of fumonisins to monitor fungal growth in mixed cultures in vitro and in co-infected plants by real-time PCR. In autoclaved grains as well as in maize ears, the growth of FV was stimulated by FG regardless of the production of DON or NIV by the latter, whereas the growth of FG was suppressed. In autoclaved grains, fumonisin-producing FV suppressed FG more strongly than a fumonisin-nonproducing strain, indicating that fumonisins act as interference competition agents. In co-infected maize ears, FG suppression was independent of fumonisin production by FV, likely due to heterogeneous infection and a lower level of fumonisins in planta. We conclude that (i) fumonisins are agents of interference competition of FV, and (ii) trichothecenes play no role in the interaction between FG and FV. We hypothesize the following: (i) In vitro, FG stimulates the FV growth by secreting hydrolases that mobilize nutrients. In planta, suppression of plant defense by FG may additionally play a role. (ii) The biological function of fumonisin production in planta is to protect kernels shed on the ground by accumulating protective metabolites before competitors become established. Therefore, to decipher the biological function of mycotoxins, the entire life history of mycotoxin producers must be considered.
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Affiliation(s)
- Mohammed Sherif
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
- Phytopathology Unit, Plant Protection Department, Desert Research Center, Cairo 11753, Egypt
| | - Nadine Kirsch
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for National and International Plant Health, Julius Kühn-Institut, 38104 Braunschweig, Germany
| | - Richard Splivallo
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for Molecular Biosciences, Goethe University Frankfurt, 60438 Frankfurt am Main, Germany
- Nectariss Grasse SAS, 06130 Grasse, France
| | - Katharina Pfohl
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
- Institute for National and International Plant Health, Julius Kühn-Institut, 38104 Braunschweig, Germany
| | - Petr Karlovsky
- Molecular Phytopathology and Mycotoxin Research, University of Göttingen, 37077 Göttingen, Germany
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Elsayed SSA, Sehsah MD, Oueslati MA, Ibrahim OM, Hamden S, Seddek NH, Abo-Elmagd HI, Alkhalifah DHM, Sheteiwy MS, AbdElgawad H, El-Saadony MT, El-Tahan AM. The effect of using fresh farmyard manure (animal manure) on the severity of Fusarium verticilioides in soil, root, stem, and kernels as well as lodging and borer incidence of maize plants. FRONTIERS IN PLANT SCIENCE 2023; 13:998440. [PMID: 36762184 PMCID: PMC9907084 DOI: 10.3389/fpls.2022.998440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 11/28/2022] [Indexed: 06/18/2023]
Abstract
Fusarium verticillioides, an important maize pathogen, produce fumonisins, causes stalk rot and consequentially reduce crop growth and yield. Therefore, herein we aimed to evaluate the potential use of two farmyard soil organic manures, i.e., fresh (5-6 days old) and stored (5-6 months old) organic manure, to manage F. verticillioides infections as well as borer incidence and lodging in maize plants. After 30, 60, and 90 days of sowing, samples of soil, roots, and stems were collected to isolate F. verticillioides. Moreover, we estimated ear and kernel rot induced by F. verticillioides at the final harvest. Fresh organic manure treatment increased infection rates of F. verticillioides in soil, roots, stem and kernels compared to the control treatment. In contrast, stored organic manure plots treatments decrease F. verticillioides frequency. At 90 days after sowing, stored organic manure suppressed the survival of F. verticillioides, which reduced the F. verticillioides incidence percent. These results were similar to the effect of herbicides-and insecticide-treated plots demonstrated, which show a significant decrease in F. verticillioides incidence rates. Mycological analysis on symptomless kernels revealed a higher % of pathogen infection in opened husks variety (Balady) than closed husks variety (SC10). Compared with stored organic manure, the stem borer incidence and lodging percentage were the highest in fresh organic manure plots. Finally, these results demonstrated that storing organic manure within five to six months as farmyard manure led to high-temperature centigrade within organic manure, thereby destroying spores of F. verticillioides, whereas fresh organic manure did not.
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Affiliation(s)
- Samar S. A. Elsayed
- Maize and Sugar Crops Disease Research Department, Plant Pathology Research Institution, Agricultural Research Center, Giza, Egypt
| | - Mohamed D. Sehsah
- Maize and Sugar Crops Disease Research Department, Plant Pathology Research Institution, Agricultural Research Center, Giza, Egypt
| | - Moufida A. Oueslati
- Deanship of Preparatory Year and Supporting Studies and The Department of Respiratory Care, College of Applied Medical Sciences in al Jubail, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Omar M. Ibrahim
- Plant Production Department, Arid Lands Cultivation Research Institute, The City of Scientific Research and Technological Applications, SRTA-City, Alexandria, Egypt
| | - Salem Hamden
- Department of Agric. Botany (Plant Pathology), Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, Egypt
| | - Nermien H. Seddek
- Department of Respiratory Care, College of Applied Medical Sciences-Jubail 4030 (CAMSJ), Imam Abdulrahman Bin Faisal University, Al Jubail, Saudi Arabia
| | - Heba I. Abo-Elmagd
- Department of Basic Sciences, Deanship of Preparatory Year and Supporting Studies, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Dalal Hussien M. Alkhalifah
- Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia
| | - Mohamed S. Sheteiwy
- Department of Agronomy, Faculty of Agriculture, Mansoura University, Mansoura, Egypt
| | - Hamada AbdElgawad
- Department of Botany and Microbiology, Faculty of Science, Beni-Suef University, Beni Suef, Egypt
| | - Mohamed T. El-Saadony
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig, Egypt
| | - Amira M. El-Tahan
- Plant Production Department, Arid Lands Cultivation Research Institute, The City of Scientific Research and Technological Applications, SRTA-City, Alexandria, Egypt
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Zhang H, Kim MS, Huang J, Yan H, Yang T, Song L, Yu W, Shim WB. Transcriptome analysis of maize pathogen Fusarium verticillioides revealed FvLcp1, a secreted protein with type-D fungal LysM and chitin-binding domains, that plays important roles in pathogenesis and mycotoxin production. Microbiol Res 2022; 265:127195. [PMID: 36126492 DOI: 10.1016/j.micres.2022.127195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/21/2022] [Accepted: 09/07/2022] [Indexed: 11/15/2022]
Abstract
Fusarium verticillioides is a key maize pathogen and produces fumonisins, a group of mycotoxins detrimental to humans and animals. Unfortunately, our understanding on how this fungus interacts with maize to trigger mycotoxin biosynthesis is limited. We performed a systematic computational network-based analysis of large-scale F. verticillioides RNA-seq datasets to identify gene subnetwork modules associated with virulence and fumonisin regulation. F. verticillioides was inoculated on two different maize lines, moderately resistant line hybrid 33K44 and highly susceptible line maize inbred line B73, to generate time-course RNA-Seq data. Among the highly discriminative subnetwork modules, we identified a putative hub gene FvLCP1, which encodes a putative a type-D fungal LysM protein with a signal peptide, three LysM domains, and two chitin binding domains. FvLcp1 is a unique protein that harbors these domains amongst five representative Fusarium species. FvLcp1 is a secreted protein important for fumonisin production with the LysM domain playing a critical role. The chitin-binding domain was essential for in vitro chitin binding. Using Magnaporthe oryzae, we learned that FvLcp1 accumulates in appressoria, suggesting that FvLcp1 is involved in host recognition and infection. Full length FvLcp1 suppressed BAX-triggered plant cell death in Nicotiana benthamiana. This unique type-D LysM secreted protein with a chitin-binding domain in F. verticillioides was shown to be potentially involved in suppressing host cell death and promoting fumonisin biosynthesis while the pathogen colonizes maize kernels.
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Affiliation(s)
- Huan Zhang
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, USA.
| | - Man S Kim
- Clinical Research Institute, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, South Korea
| | - Jun Huang
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Huijuan Yan
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, USA
| | - Tao Yang
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Linlin Song
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wenying Yu
- Fujian University Key Laboratory for Functional Genomics of Plant Fungal Pathogens, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Won Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, USA.
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Iqbal N, Czékus Z, Poór P, Ördög A. Plant defence mechanisms against mycotoxin Fumonisin B1. Chem Biol Interact 2021; 343:109494. [PMID: 33915161 DOI: 10.1016/j.cbi.2021.109494] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/30/2021] [Accepted: 04/21/2021] [Indexed: 10/21/2022]
Abstract
Fumonisin B1 (FB1) is the most harmful mycotoxin which prevails in several crops and affects the growth and yield as well. Hence, keeping the alarming consequences of FB1 under consideration, there is still a need to seek other more reliable approaches and scientific knowledge for FB1-induced cell death and a comprehensive understanding of the mechanisms of plant defence strategies. FB1-induced disturbance in sphingolipid metabolism initiates programmed cell death (PCD) through various modes such as the elevated generation of reactive oxygen species, lipid peroxidation, cytochrome c release from the mitochondria, and activation of specific proteases and nucleases causing DNA fragmentation. There is a close interaction between sphingolipids and defence phytohormones in response to FB1 exposure regulating PCD and defence. In this review, the model plant Arabidopsis and various crops have been presented with different levels of susceptibility and resistivity exposed to various concentration of FB1. In addition to this, regulation of PCD and defence mechanisms have been also demonstrated at the physiological, biochemical and molecular levels to help the understanding of the role and function of FB1-inducible molecules and genes and their expressions in plants against pathogen attacks which could provide molecular and biochemical markers for the detection of toxin exposure.
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Affiliation(s)
- Nadeem Iqbal
- Department of Plant Biology, University of Szeged, H-6726, Szeged, Közép fasor 52., Hungary; Doctoral School of Environmental Sciences, University of Szeged, Szeged, Hungary
| | - Zalán Czékus
- Department of Plant Biology, University of Szeged, H-6726, Szeged, Közép fasor 52., Hungary; Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - Péter Poór
- Department of Plant Biology, University of Szeged, H-6726, Szeged, Közép fasor 52., Hungary.
| | - Attila Ördög
- Department of Plant Biology, University of Szeged, H-6726, Szeged, Közép fasor 52., Hungary
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7
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Physical and chemical parameters, Fusarium verticillioides growth and fumonisin production in kernels of nine maize genotypes. J Cereal Sci 2020. [DOI: 10.1016/j.jcs.2020.103128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Links S, van Zyl K, Cassiem A, Flett B, Viljoen A, Rose L. The association of maize characteristics with resistance to Fusarium verticillioides and fumonisin accumulation in commercial maize cultivars. WORLD MYCOTOXIN J 2020. [DOI: 10.3920/wmj2019.2537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fusarium verticillioides is the primary fungus that causes Fusarium ear rot (FER) of maize. Infection results in reduced grain yield and quality due to moulding and the contamination of grain with toxic compounds namely fumonisins. Resistance to fungal infection and fumonisin accumulation in maize and maize grain is governed at different levels. In this study, the structural, physico-chemical and genetic basis of resistance to F. verticillioides was investigated in two, replicated field trials at Potchefstroom and Vaalharts in South Africa. Phenotypic data (silk length, husk coverage, pericarp thickness hundred-kernel mass and kernel hardness), physico-chemical data (kernel pH, moisture content, total nitrogen and carbon as well as phenolic acid content) and the expression of pathogenesis-related-5 gene (PR5) and peroxidase gene expression was evaluated in 15 commercial cultivars under artificially inoculated and natural infection conditions. The data were correlated to FER severity, fumonisin accumulation and fungal DNA (referred to as infection indicators). Disease development and fumonisin contamination in Vaalharts was significantly more than in Potchefstroom. There were no significant correlations (r=≥0.60) between phenotypic characteristics and infection indicators. Kernel pH was the most important trait associated with disease development and was negatively correlated (between r=-0.58 and r=-0.75) to all infection indicators. PR5 gene expression had significant positive correlations (r=0.69 and r=0.72) with the fungal and fumonisin levels, respectively. This study presents of the first data demonstrating the use of gene expression in identifying FER/fumonisin-resistant plant material and could aid breeders and growers in selecting resistant material more effectively.
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Affiliation(s)
- S. Links
- Stellenbosch University, Faculty of AgriSciences, Stellenbosch, Matieland 7602, South Africa
- Grain SA, Research and Policy Centre, 457 Witherite Street, Willow Acres, Pretoria, 7600, South Africa
| | - K. van Zyl
- Stellenbosch University, Faculty of AgriSciences, Stellenbosch, Matieland 7602, South Africa
| | - A. Cassiem
- Stellenbosch University, Faculty of AgriSciences, Stellenbosch, Matieland 7602, South Africa
| | - B.C. Flett
- Agricultural Research Council, Grain Crops, Potchefstroom, 2520, South Africa
| | - A. Viljoen
- Stellenbosch University, Faculty of AgriSciences, Stellenbosch, Matieland 7602, South Africa
| | - L.J. Rose
- Stellenbosch University, Faculty of AgriSciences, Stellenbosch, Matieland 7602, South Africa
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Lumsangkul C, Chiang HI, Lo NW, Fan YK, Ju JC. Developmental Toxicity of Mycotoxin Fumonisin B₁ in Animal Embryogenesis: An Overview. Toxins (Basel) 2019; 11:E114. [PMID: 30781891 PMCID: PMC6410136 DOI: 10.3390/toxins11020114] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 02/02/2019] [Accepted: 02/11/2019] [Indexed: 11/24/2022] Open
Abstract
A teratogenic agent or teratogen can disturb the development of an embryo or a fetus. Fumonisin B₁ (FB₁), produced by Fusarium verticillioides and F. proliferatum, is among the most commonly seen mycotoxins and contaminants from stale maize and other farm products. It may cause physical or functional defects in embryos or fetuses, if the pregnant animal is exposed to mycotoxin FB₁. Due to its high similarity in chemical structure with lipid sphinganine (Sa) and sphingosine (So), the primary component of sphingolipids, FB₁ plays a role in competitively inhibiting Sa and So, which are key enzymes in de novo ceramide synthase in the sphingolipid biosynthetic pathway. Therefore, it causes growth retardation and developmental abnormalities to the embryos of hamsters, rats, mice, and chickens. Moreover, maternal FB₁ toxicity can be passed onto the embryo or fetus, leading to mortality. FB₁ also disrupts folate metabolism via the high-affinity folate transporter that can then result in folate insufficiency. The deficiencies are closely linked to incidences of neural tube defects (NTDs) in mice or humans. The purpose of this review is to understand the toxicity and mechanisms of mycotoxin FB₁ on the development of embryos or fetuses.
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Affiliation(s)
- Chompunut Lumsangkul
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Hsin-I Chiang
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Neng-Wen Lo
- Department of Animal Science and Biotechnology, Tunghai University, Taichung 40704, Taiwan.
| | - Yang-Kwang Fan
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.
| | - Jyh-Cherng Ju
- Department of Animal Science, National Chung Hsing University, Taichung 40227, Taiwan.
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402, Taiwan.
- Translational Medicine Research Center, China Medical University Hospital, Taichung 40402, Taiwan.
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan.
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Vanara F, Scarpino V, Blandino M. Fumonisin Distribution in Maize Dry-Milling Products and By-Products: Impact of Two Industrial Degermination Systems. Toxins (Basel) 2018; 10:E357. [PMID: 30181489 PMCID: PMC6162726 DOI: 10.3390/toxins10090357] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/09/2018] [Accepted: 08/18/2018] [Indexed: 11/17/2022] Open
Abstract
In temperate areas, the main limitation to the use of maize in the food chain is its contamination by B-series fumonisins (FBs) during cultivation. Since the content of this group of mycotoxins may be distributed unevenly after milling, the aim of this study was to compare the distribution of FBs in maize fractions derived from two industrial dry-milling processes, that is, a dry-degermination (DD) system and a tempering-degermination (TD) system. Grain cleaning reduces FBs by about 42%. The germ of the two degermination processes showed a similar FB content of kernel after cleaning. Conversely, an animal feed flour resulted in a FB content that was two times higher than whole grain before cleaning. A significant FB reduction was observed in the milling fractions in both processes, with a higher reduction in the TD system than in the DD one. The average decontamination respect to uncleaned kernels in the DD process was 50%, 83% and 87%, for maize flour, break meal and pearl meal, respectively, while it was 78%, 88% and 94% in the TD process for small, medium and flaking grits, respectively. Among the milling fractions, the flaking grits with the highest particle size resulted in the highest FB reduction.
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Affiliation(s)
- Francesca Vanara
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy.
| | - Valentina Scarpino
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy.
| | - Massimo Blandino
- Dipartimento di Scienze Agrarie, Forestali e Alimentari, Università degli Studi di Torino, Largo Paolo Braccini, 2, 10095 Grugliasco, Italy.
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11
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Gai X, Dong H, Wang S, Liu B, Zhang Z, Li X, Gao Z. Infection cycle of maize stalk rot and ear rot caused by Fusarium verticillioides. PLoS One 2018; 13:e0201588. [PMID: 30063754 PMCID: PMC6067754 DOI: 10.1371/journal.pone.0201588] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 07/18/2018] [Indexed: 11/19/2022] Open
Abstract
Fusarium verticillioides, an important maize pathogen produces fumonisins and causes stalk and ear rot; thus, we are aimed to clarify its infection cycle by assessing enhanced green fluorescent protein (EGFP) expression in stalk and ear rot strains. Maize seeds were inoculated with stable and strongly pathogenic transformants. To investigate the degree of infection, inoculated plants were observed under a stereo fluorescence microscope, and affected tissue strains were detected using PCR. We found that both transformants infected maize. Hyphae infected the plants from radical to the stem and extended to the ear and infected ear kernels caused a second infection. This process formed the infection cycle.
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Affiliation(s)
- Xiaotong Gai
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Huaiyu Dong
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- Institute of Plant Protection, Academy of Agricultural Sciences of Liaoning, Shenyang, China
| | - Suna Wang
- College of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, China
| | - Bo Liu
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Zhaoran Zhang
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Xiaoyang Li
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Zenggui Gao
- Ministry of Agriculture Key Laboratory of Northern Crop Immunology, College of Plant Protection, Shenyang Agricultural University, Shenyang, China
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Blacutt AA, Gold SE, Voss KA, Gao M, Glenn AE. Fusarium verticillioides: Advancements in Understanding the Toxicity, Virulence, and Niche Adaptations of a Model Mycotoxigenic Pathogen of Maize. PHYTOPATHOLOGY 2018; 108:312-326. [PMID: 28971734 DOI: 10.1094/phyto-06-17-0203-rvw] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The importance of understanding the biology of the mycotoxigenic fungus Fusarium verticillioides and its various microbial and plant host interactions is critical given its threat to maize, one of the world's most valuable food crops. Disease outbreaks and mycotoxin contamination of grain threaten economic returns and have grave implications for human and animal health and food security. Furthermore, F. verticillioides is a member of a genus of significant phytopathogens and, thus, data regarding its host association, biosynthesis of secondary metabolites, and other metabolic (degradative) capabilities are consequential to both basic and applied research efforts across multiple pathosystems. Notorious among its secondary metabolites are the fumonisin mycotoxins, which cause severe animal diseases and are implicated in human disease. Additionally, studies of these mycotoxins have led to new understandings of F. verticillioides plant pathogenicity and provide tools for research into cellular processes and host-pathogen interaction strategies. This review presents current knowledge regarding several significant lines of F. verticillioides research, including facets of toxin production, virulence, and novel fitness strategies exhibited by this fungus across rhizosphere and plant environments.
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Affiliation(s)
- Alex A Blacutt
- First and fourth authors: Department of Plant Pathology, University of Georgia, Athens 30602; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. National Poultry Research Center, Toxicology and Mycotoxin Research Unit, Athens, GA 30605-2720
| | - Scott E Gold
- First and fourth authors: Department of Plant Pathology, University of Georgia, Athens 30602; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. National Poultry Research Center, Toxicology and Mycotoxin Research Unit, Athens, GA 30605-2720
| | - Kenneth A Voss
- First and fourth authors: Department of Plant Pathology, University of Georgia, Athens 30602; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. National Poultry Research Center, Toxicology and Mycotoxin Research Unit, Athens, GA 30605-2720
| | - Minglu Gao
- First and fourth authors: Department of Plant Pathology, University of Georgia, Athens 30602; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. National Poultry Research Center, Toxicology and Mycotoxin Research Unit, Athens, GA 30605-2720
| | - Anthony E Glenn
- First and fourth authors: Department of Plant Pathology, University of Georgia, Athens 30602; and second, third, and fifth authors: United States Department of Agriculture-Agricultural Research Service, U.S. National Poultry Research Center, Toxicology and Mycotoxin Research Unit, Athens, GA 30605-2720
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13
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Niu C, Payne GA, Woloshuk CP. Involvement of FST1 from Fusarium verticillioides in virulence and transport of inositol. MOLECULAR PLANT PATHOLOGY 2017; 18:695-707. [PMID: 27195938 PMCID: PMC6638204 DOI: 10.1111/mpp.12430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 05/11/2016] [Accepted: 05/13/2016] [Indexed: 06/05/2023]
Abstract
Fumonisin B1 (FB1), a polyketide mycotoxin produced by Fusarium verticillioides during the colonization of maize kernels, is detrimental to human and animal health. FST1 encodes a putative protein with 12 transmembrane domains; however, its function remains unknown. The FST1 gene is highly expressed by the fungus in the endosperm of maize kernels compared with the levels of expression in germ tissues. Previous research has shown that FST1 affects FB1 production, virulence, hydrogen peroxide resistance, hydrophobicity and macroconidia production. Here, we examine the phylogeny of FST1, its expression in a Saccharomyces cerevisiae strain lacking a functional myo-inositol transporter (ITR1) and the effect of amino acid changes in the central loop and C-terminus regions of FST1 on functionality. The results indicate that expression of FST1 in an ITR1 mutant strain restores growth on myo-inositol medium to wild-type levels and restores the inhibitory effects of FB1, suggesting that FST1 can transport both myo-inositol and FB1 into yeast cells. Our results with engineered FST1 also indicate that amino acids in the central loop and C-terminus regions are important for FST1 functionality in both S. cerevisiae and F. verticillioides. Overall, this research has established the first characterized inositol transporter in filamentous fungi and has advanced our knowledge about the global regulatory functions of FST1.
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Affiliation(s)
- Chenxing Niu
- Department of Botany and Plant PathologyPurdue UniversityWest LafayetteIN47907‐2054USA
| | - Gary A. Payne
- Department of Plant PathologyNorth Carolina State UniversityRaleighNC27695‐7567USA
| | - Charles P. Woloshuk
- Department of Botany and Plant PathologyPurdue UniversityWest LafayetteIN47907‐2054USA
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14
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Bordini JG, Ono MA, Garcia GT, Fazani VHM, Vizoni É, Rodrigues KCB, Hirooka EY, Ono EYS. Impact of industrial dry-milling on fumonisin redistribution in non-transgenic corn in Brazil. Food Chem 2016; 220:438-443. [PMID: 27855923 DOI: 10.1016/j.foodchem.2016.10.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 10/05/2016] [Accepted: 10/06/2016] [Indexed: 10/20/2022]
Abstract
The aim of this study was to evaluate the fate of fumonisins B1 (FB1) and B2 (FB2) during industrial dry-milling in two lots from 2014 (n=120) and 2015 (n=120) of non-transgenic corn and their fractions (germ, pericarp, endosperm, cornmeal and grits), collected from one of the major Brazilian milling industries. Fumonisins were concentrated in the germ and pericarp at a rate of 322% and 188% (lot 1) and 311% and 263% (lot 2), respectively. In the endosperm, cornmeal and grits fumonisin levels decreased from 60 to 95%. Fumonisin levels in cornmeal and grits were below the maximum limit tolerated by the European Commission. Therefore, corn industrial dry-milling can contribute to reducing fumonisin levels in corn products intended for human consumption.
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Affiliation(s)
- Jaqueline Gozzi Bordini
- State University of Londrina, Department of Biochemistry and Biotechnology, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil
| | - Mario Augusto Ono
- State University of Londrina, Department of Pathological Sciences, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil
| | | | - Victor Hugo Meconi Fazani
- State University of Londrina, Department of Biochemistry and Biotechnology, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil
| | - Édio Vizoni
- State University of Londrina, Department of Applied Mathematics, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil
| | | | - Elisa Yoko Hirooka
- State University of Londrina, Department of Food Science and Technology, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil
| | - Elisabete Yurie Sataque Ono
- State University of Londrina, Department of Biochemistry and Biotechnology, P.O. Box 10.011, Zip Code 86057-970 Londrina, Paraná, Brazil.
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15
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Oh M, Son H, Choi GJ, Lee C, Kim JC, Kim H, Lee YW. Transcription factor ART1 mediates starch hydrolysis and mycotoxin production in Fusarium graminearum and F. verticillioides. MOLECULAR PLANT PATHOLOGY 2016; 17:755-68. [PMID: 26456718 PMCID: PMC6638531 DOI: 10.1111/mpp.12328] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Molecular mechanisms underlying the responses to environmental factors, such as nitrogen, carbon and pH, involve components that regulate the production of secondary metabolites, including mycotoxins. In this study, we identified and characterized a gene in the FGSG_02083 locus, designated as FgArt1, which was predicted to encode a Zn(II)2 Cys6 zinc finger transcription factor. An FgArt1 deletion mutant of Fusarium graminearum exhibited impaired starch hydrolysis as a result of significantly reduced α-amylase gene expression. The deletion strain was unable to produce trichothecenes and exhibited low Tri5 and Tri6 expression levels, whereas the complemented strain showed a similar ability to produce trichothecenes as the wild-type strain. In addition, FgArt1 deletion resulted in impairment of germination in starch liquid medium and reduced pathogenicity on flowering wheat heads. To investigate the roles of the FgArt1 homologue in F. verticillioides, we deleted the FVEG_02083 gene, and the resulting strain showed defects in starch hydrolysis, similar to the FgArt1 deletion strain, and produced no detectable level of fumonisin B1 . Fum1 and Fum12 expression levels were undetectable in the deletion strain. However, when the FvArt1-deleted F. verticillioides strain was complemented with FgArt1, the resulting strain was unable to recover the production of fumonisin B1 , although FgArt1 expression and starch hydrolysis were induced. Thus, our results suggest that there are different regulatory pathways governed by each ART1 transcription factor in trichothecene and fumonisin biosynthesis. Taken together, we suggest that ART1 plays an important role in both trichothecene and fumonisin biosynthesis by the regulation of genes involved in starch hydrolysis.
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Affiliation(s)
- Mira Oh
- Center for Eco-Friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, 305-600, South Korea
- Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon, 305-350, South Korea
| | - Hokyoung Son
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, 151-921, South Korea
| | - Gyung Ja Choi
- Center for Eco-Friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, 305-600, South Korea
| | - Chanhui Lee
- Department of Plant and Environmental New Resources, Kyung Hee University, Yongin, 446-701, South Korea
| | - Jin-Cheol Kim
- Division of Applied Bioscience and Biotechnology, Chonnam National University, Gwangju, 500-757, South Korea
| | - Hun Kim
- Center for Eco-Friendly New Materials, Korea Research Institute of Chemical Technology, Daejeon, 305-600, South Korea
- Department of Green Chemistry and Environmental Biotechnology, Korea University of Science and Technology, Daejeon, 305-350, South Korea
| | - Yin-Won Lee
- Department of Agricultural Biotechnology and Center for Fungal Pathogenesis, Seoul National University, Seoul, 151-921, South Korea
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16
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Ortiz CS, Richards C, Terry A, Parra J, Shim WB. Genetic Variability and Geographical Distribution of Mycotoxigenic Fusarium verticillioides Strains Isolated from Maize Fields in Texas. THE PLANT PATHOLOGY JOURNAL 2015; 31:203-11. [PMID: 26361468 PMCID: PMC4564145 DOI: 10.5423/ppj.oa.02.2015.0020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 04/22/2015] [Accepted: 04/29/2015] [Indexed: 06/01/2023]
Abstract
Maize is the dominant cereal crop produced in the US. One of the main fungal pathogens of maize is Fusarium verticillioides, the causative agent of ear and stalk rots. Significantly, the fungus produces a group of mycotoxins - fumonisins - on infested kernels, which have been linked to various illnesses in humans and animals. Nonetheless, durable resistance against F. verticillioides in maize is not currently available. In Texas, over 2.1 million acres of maize are vulnerable to fumonisin contamination, but understanding of the distribution of toxigenic F. verticillioides in maize-producing areas is currently lacking. Our goal was to investigate the genetic variability of F. verticillioides in Texas with an emphasis on fumonisin trait and geographical distribution. A total of 164 F. verticillioides cultures were isolated from 65 maize-producing counties. DNA from each isolate was extracted and analyzed by PCR for the presence of FUM1- a key fumonisin biosynthesis gene - and mating type genes. Results showed that all isolates are in fact F. verticillioides capable of producing fumonisins with a 1:1 mating-type gene ratio in the population. To further study the genetic diversity of the population, isolates were analyzed using RAPD fingerprinting. Polymorphic markers were identified and the analysis showed no clear correlation between the RAPD profile of the isolates and their corresponding geographical origin. Our data suggest the toxigenic F. verticillioides population in Texas is widely distributed wherever maize is grown. We also hypothesize that the population is fluid, with active movement and genetic recombination occurring in the field.
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Affiliation(s)
- Carlos S. Ortiz
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132,
USA
| | - Casey Richards
- Bioenvironmental Sciences Program, Texas A&M University, College Station, TX 77843-2132,
USA
| | - Ashlee Terry
- Bioenvironmental Sciences Program, Texas A&M University, College Station, TX 77843-2132,
USA
| | - Joselyn Parra
- Bioenvironmental Sciences Program, Texas A&M University, College Station, TX 77843-2132,
USA
| | - Won-Bo Shim
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132,
USA
- Bioenvironmental Sciences Program, Texas A&M University, College Station, TX 77843-2132,
USA
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17
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Santiago R, Cao A, Butrón A. Genetic Factors Involved in Fumonisin Accumulation in Maize Kernels and Their Implications in Maize Agronomic Management and Breeding. Toxins (Basel) 2015; 7:3267-96. [PMID: 26308050 PMCID: PMC4549750 DOI: 10.3390/toxins7083267] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/05/2015] [Accepted: 08/11/2015] [Indexed: 11/23/2022] Open
Abstract
Contamination of maize with fumonisins depends on the environmental conditions; the maize resistance to contamination and the interaction between both factors. Although the effect of environmental factors is a determinant for establishing the risk of kernel contamination in a region, there is sufficient genetic variability among maize to develop resistance to fumonisin contamination and to breed varieties with contamination at safe levels. In addition, ascertaining which environmental factors are the most important in a region will allow the implementation of risk monitoring programs and suitable cultural practices to reduce the impact of such environmental variables. The current paper reviews all works done to address the influence of environmental variables on fumonisin accumulation, the genetics of maize resistance to fumonisin accumulation, and the search for the biochemical and/or structural mechanisms of the maize plant that could be involved in resistance to fumonisin contamination. We also explore the outcomes of breeding programs and risk monitoring of undertaken projects.
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Affiliation(s)
- Rogelio Santiago
- Facultad de Biología, Dpt Biología Vegetal y Ciencias del Suelo, Universidad de Vigo, As Lagoas Marcosende, Vigo 36310, Spain.
- Agrobiología Ambiental, Calidad de Suelos y Plantas (UVIGO), Unidad Asociada a la Misión Biológica de Galicia (CSIC), Pontevedra 36143, Spain.
| | - Ana Cao
- Misión Biológica de Galicia (CSIC), Box 28, Pontevedra 36080, Spain.
| | - Ana Butrón
- Misión Biológica de Galicia (CSIC), Box 28, Pontevedra 36080, Spain.
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18
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Ridenour JB, Smith JE, Hirsch RL, Horevaj P, Kim H, Sharma S, Bluhm BH. UBL1 of Fusarium verticillioides links the N-end rule pathway to extracellular sensing and plant pathogenesis. Environ Microbiol 2013; 16:2004-22. [PMID: 24237664 DOI: 10.1111/1462-2920.12333] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/07/2013] [Indexed: 01/06/2023]
Abstract
Fusarium verticillioides produces fumonisin mycotoxins during colonization of maize. Currently, molecular mechanisms underlying responsiveness of F.verticillioides to extracellular cues during pathogenesis are poorly understood. In this study, insertional mutants were created and screened to identify genes involved in responses to extracellular starch. In one mutant, the restriction enzyme-mediated integration cassette disrupted a gene (UBL1) encoding a UBR-Box/RING domain E3 ubiquitin ligase involved in the N-end rule pathway. Disruption of UBL1 in F.verticillioides (Δubl1) influenced conidiation, hyphal morphology, pigmentation and amylolysis. Disruption of UBL1 also impaired kernel colonization, but the ratio of fumonisin B1 per unit growth was not significantly reduced. The inability of a Δubl1 mutant to recognize an N-end rule degron confirmed involvement of UBL1 in the N-end rule pathway. Additionally, Ubl1 physically interacted with two G protein α subunits of F.verticillioides, thus implicating UBL1 in G protein-mediated sensing of the external environment. Furthermore, deletion of the UBL1 orthologue in F.graminearum reduced virulence on wheat and maize, thus indicating that UBL1 has a broader role in virulence among Fusarium species. This study provides the first linkage between the N-end rule pathway and fungal pathogenesis, and illustrates a new mechanism through which fungi respond to the external environment.
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Affiliation(s)
- John B Ridenour
- Department of Plant Pathology, Division of Agriculture, University of Arkansas, Fayetteville, AR, 72701, USA
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19
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Wu L, Wang X, Xu R, Li H. Difference between resistant and susceptible maize to systematic colonization as revealed by DsRed-labeled Fusarium verticillioides. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.cj.2013.07.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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20
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Scala V, Camera E, Ludovici M, Dall'Asta C, Cirlini M, Giorni P, Battilani P, Bello C, Fabbri A, Fanelli C, Reverberi M. Fusarium verticillioides and maize interaction in vitro: relationship between oxylipin cross-talk and fumonisin synthesis. WORLD MYCOTOXIN J 2013. [DOI: 10.3920/wmj2012.1527] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fusarium verticillioides is one of the most important fungal pathogens causing ear and stalk rot in maize. Even if frequently asymptomatic, it can produce a harmful series of compounds named fumonisins. Plant and fungal oxylipins play a crucial role in determining the outcome of the interaction between the pathogen and its host. Moreover, oxylipins are factors able to modulate the secondary metabolism in fungi. To uncover the existence of the relationship between oxylipin production and fumonisin synthesis in F. verticillioides, we analysed some molecular and physiological parameters, such as the expression of genes whose products are related to oxylipin synthesis (i.e. lipoxygenase, diol synthases and fatty acid oxidase), the oxylipin profile of both cracked maize and the pathogen by using a lipidomic approach (i.e. combining LC-TOF and LC-MS/MS approaches with a robust statistical analysis) and the synthesis of fumonisin B1. The results suggested a close relationship between the modification of the pathogen oxylipin profile with the fumonisin synthesis. Notably, a modification of the oxylipin profile of the pathogen during its growth on cracked maize can be demonstrated. The switch in oxylipin synthesis could indicate that the ‘presence’ of maize determinants (e.g. plant cell wall fragments and/or lipids) was able to promote the modification of the pathogen lifestyle, also by adapting the secondary metabolism, notably fumonisin synthesis.
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Affiliation(s)
- V. Scala
- Dipartimento di Biologia Ambientale, Università ‘Sapienza’, Largo Cristina di Svezia 24, 00165 Rome, Italy
| | - E. Camera
- Laboratorio di Fisiopatologia Cutanea e Centro Integrato di Metabolomica, Istituto Dermatologico San Gallicano IRCCS, Via Chianesi 53, 00144 Rome, Italy
| | - M. Ludovici
- Laboratorio di Fisiopatologia Cutanea e Centro Integrato di Metabolomica, Istituto Dermatologico San Gallicano IRCCS, Via Chianesi 53, 00144 Rome, Italy
| | - C. Dall'Asta
- Dipartimento di Chimica Organica e Industriale, ‘Università degli Studi di Parma’, Parco Area delle Scienze 17/A, 43124 Parma, Italy
| | - M. Cirlini
- Dipartimento di Chimica Organica e Industriale, ‘Università degli Studi di Parma’, Parco Area delle Scienze 17/A, 43124 Parma, Italy
| | - P. Giorni
- Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, via Emilia Parmense 84, 29122 Piacenza, Italy
| | - P. Battilani
- Istituto di Entomologia e Patologia Vegetale, Università Cattolica del Sacro Cuore, via Emilia Parmense 84, 29122 Piacenza, Italy
| | - C. Bello
- Dipartimento di Biologia Ambientale, Università ‘Sapienza’, Largo Cristina di Svezia 24, 00165 Rome, Italy
| | - A.A. Fabbri
- Dipartimento di Biologia Ambientale, Università ‘Sapienza’, Largo Cristina di Svezia 24, 00165 Rome, Italy
| | - C. Fanelli
- Dipartimento di Biologia Ambientale, Università ‘Sapienza’, Largo Cristina di Svezia 24, 00165 Rome, Italy
| | - M. Reverberi
- Dipartimento di Biologia Ambientale, Università ‘Sapienza’, Largo Cristina di Svezia 24, 00165 Rome, Italy
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Shin JH, Kim JE, Malapi-Wight M, Choi YE, Shaw BD, Shim WB. Protein phosphatase 2A regulatory subunits perform distinct functional roles in the maize pathogen Fusarium verticillioides. MOLECULAR PLANT PATHOLOGY 2013; 14:518-29. [PMID: 23452277 PMCID: PMC6638791 DOI: 10.1111/mpp.12023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fusarium verticillioides is a pathogen of maize causing ear rot and stalk rot. The fungus also produces fumonisins, a group of mycotoxins linked to disorders in animals and humans. A cluster of genes, designated FUM genes, plays a key role in the synthesis of fumonisins. However, our understanding of the regulatory mechanism of fumonisin biosynthesis is still incomplete. We have demonstrated previously that Cpp1, a protein phosphatase type 2A (PP2A) catalytic subunit, negatively regulates fumonisin production and is involved in cell shape maintenance. In general, three PP2A subunits, structural A, regulatory B and catalytic C, make up a heterotrimer complex to perform regulatory functions. Significantly, we identified two PP2A regulatory subunits in the F. verticillioides genome, Ppr1 and Ppr2, which are homologous to Saccharomyces cerevisiae Cdc55 and Rts1, respectively. In this study, we hypothesized that Ppr1 and Ppr2 are involved in the regulation of fumonisin biosynthesis and/or cell development in F. verticillioides, and generated a series of mutants to determine the functional role of Ppr1 and Ppr2. The PPR1 deletion strain (Δppr1) resulted in drastic growth defects, but increased microconidia production. The PPR2 deletion mutant strain (Δppr2) showed elevated fumonisin production, similar to the Δcpp1 strain. Germinating Δppr1 conidia formed abnormally swollen cells with a central septation site, whereas Δppr2 showed early hyphal branching during conidia germination. A kernel rot assay showed that the mutants were slow to colonize kernels, but this is probably a result of growth defects rather than a virulence defect. Results from this study suggest that two PP2A regulatory subunits in F. verticillioides carry out distinct roles in the regulation of fumonisin biosynthesis and fungal development.
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Affiliation(s)
- Joon-Hee Shin
- Department of Plant Pathology and Microbiology, Texas A&M University, College Station, TX 77843-2132, USA
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22
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Woloshuk CP, Shim WB. Aflatoxins, fumonisins, and trichothecenes: a convergence of knowledge. FEMS Microbiol Rev 2012; 37:94-109. [PMID: 23078349 DOI: 10.1111/1574-6976.12009] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/27/2012] [Accepted: 10/15/2012] [Indexed: 01/03/2023] Open
Abstract
Plant pathogenic fungi Aspergillus flavus, Fusarium verticillioides, and Fusarium graminearum infect seeds of the most important food and feed crops, including maize, wheat, and barley. More importantly, these fungi produce aflatoxins, fumonisins, and trichothecenes, respectively, which threaten health and food security worldwide. In this review, we examine the molecular mechanisms and environmental factors that regulate mycotoxin biosynthesis in each fungus, and discuss the similarities and differences in the collective body of knowledge. Whole-genome sequences are available for these fungi, providing reference databases for genomic, transcriptomic, and proteomic analyses. It is well recognized that genes responsible for mycotoxin biosynthesis are organized in clusters. However, recent research has documented the intricate transcriptional and epigenetic regulation that affects these gene clusters. Significantly, molecular networks that respond to environmental factors, namely nitrogen, carbon, and pH, are connected to components regulating mycotoxin production. Furthermore, the developmental status of seeds and specific tissue types exert conditional influences during fungal colonization. A comparison of the three distinct mycotoxin groups provides insight into new areas for research collaborations that will lead to innovative strategies to control mycotoxin contamination of grain.
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Affiliation(s)
- Charles P Woloshuk
- Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.
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23
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Christensen S, Borrego E, Shim WB, Isakeit T, Kolomiets M. Quantification of fungal colonization, sporogenesis, and production of mycotoxins using kernel bioassays. J Vis Exp 2012:3727. [PMID: 22546841 PMCID: PMC3578446 DOI: 10.3791/3727] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The rotting of grains by seed-infecting fungi poses one of the greatest economic challenges to cereal production worldwide, not to mention serious risks to human and animal health. Among cereal production, maize is arguably the most affected crop, due to pathogen-induced losses in grain integrity and mycotoxin seed contamination. The two most prevalent and problematic mycotoxins for maize growers and food and feed processors are aflatoxin and fumonisin, produced by Aspergillus flavus and Fusarium verticillioides, respectively. Recent studies in molecular plant-pathogen interactions have demonstrated promise in understanding specific mechanisms associated with plant responses to fungal infection and mycotoxin contamination(1,2,3,4,5,6). Because many labs are using kernel assays to study plant-pathogen interactions, there is a need for a standardized method for quantifying different biological parameters, so results from different laboratories can be cross-interpreted. For a robust and reproducible means for quantitative analyses on seeds, we have developed in-lab kernel assays and subsequent methods to quantify fungal growth, biomass, and mycotoxin contamination. Four sterilized maize kernels are inoculated in glass vials with a fungal suspension (10(6)) and incubated for a predetermined period. Sample vials are then selected for enumeration of conidia by hemocytometer, ergosterol-based biomass analysis by high performance liquid chromatography (HPLC), aflatoxin quantification using an AflaTest fluorometer method, and fumonisin quantification by HPLC.
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24
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Brown DW, Butchko RAE, Baker SE, Proctor RH. Phylogenomic and functional domain analysis of polyketide synthases in Fusarium. Fungal Biol 2011; 116:318-31. [PMID: 22289777 DOI: 10.1016/j.funbio.2011.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2011] [Revised: 12/09/2011] [Accepted: 12/10/2011] [Indexed: 12/15/2022]
Abstract
Fusarium species are ubiquitous in nature, cause a range of plant diseases, and produce a variety of chemicals often referred to as secondary metabolites. Although some fungal secondary metabolites affect plant growth or protect plants from other fungi and bacteria, their presence in grain-based food and feed is more often associated with a variety of diseases in plants and in animals. Many of these structurally diverse metabolites are derived from a family of related enzymes called polyketide synthases (PKSs). A search of genomic sequence of Fusarium verticillioides, Fusarium graminearum, Fusarium oxysporum, and Fusarium solani identified a total of 58 PKS genes. To gain insight into how this gene family evolved and to guide future studies, we conducted phylogenomic and functional domain analyses. The resulting geneaology suggested that Fusarium PKSs represent 34 different groups responsible for synthesis of different core metabolites. The analyses indicate that variation in the Fusarium PKS gene family is due to gene duplication and loss events as well as enzyme gain-of-function due to the acquisition of new domains or of loss-of-function due to nucleotide mutations. Transcriptional analysis indicates that the 16 F. verticillioides PKS genes are expressed under a range of conditions, further evidence that they are functional genes that confer the ability to produce secondary metabolites.
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Affiliation(s)
- Daren W Brown
- Bacterial Foodborne Pathogens and Mycology Research, USDA-ARS-NCAUR, Peoria, Illinois 61604, USA.
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25
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Kim H, Smith JE, Ridenour JB, Woloshuk CP, Bluhm BH. HXK1 regulates carbon catabolism, sporulation, fumonisin B₁ production and pathogenesis in Fusarium verticillioides. MICROBIOLOGY-SGM 2011; 157:2658-2669. [PMID: 21719539 DOI: 10.1099/mic.0.052506-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In Fusarium verticillioides, a ubiquitous pathogen of maize, virulence and mycotoxigenesis are regulated in response to the types and amounts of carbohydrates present in maize kernels. In this study, we investigated the role of a putative hexokinase-encoding gene (HXK1) in growth, development and pathogenesis. A deletion mutant (Δhxk1) of HXK1 was not able to grow when supplied with fructose as the sole carbon source, and growth was impaired when glucose, sucrose or maltotriose was provided. Additionally, the Δhxk1 mutant produced unusual swollen hyphae when provided with fructose, but not glucose, as the sole carbon source. Moreover, the Δhxk1 mutant was impaired in fructose uptake, although glucose uptake was unaffected. On maize kernels, the Δhxk1 mutant was substantially less virulent than the wild-type, but virulence on maize stalks was not impaired, possibly indicating a metabolic response to tissue-specific differences in plant carbohydrate content. Finally, disruption of HXK1 had a pronounced effect on fungal metabolites produced during colonization of maize kernels; the Δhxk1 mutant produced approximately 50 % less trehalose and 80 % less fumonisin B₁ (FB₁) than the wild-type. The reduction in trehalose biosynthesis likely explains observations of increased sensitivity to osmotic stress in the Δhxk1 mutant. In summary, this study links early events in carbohydrate sensing and glycolysis to virulence and secondary metabolism in F. verticillioides, and thus provides a new foothold from which the genetic regulatory networks that underlie pathogenesis and mycotoxigenesis can be unravelled and defined.
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Affiliation(s)
- Hun Kim
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA.,Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Jonathon E Smith
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - John B Ridenour
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
| | - Charles P Woloshuk
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
| | - Burton H Bluhm
- Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
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Kim H, Woloshuk CP. Functional characterization of fst1 in Fusarium verticillioides during colonization of maize kernels. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2011; 24:18-24. [PMID: 20854112 DOI: 10.1094/mpmi-03-10-0074] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The putative hexose transporter gene fst1 in Fusarium verticillioides was identified previously by microarray analysis as a gene that was more highly expressed during colonization of autoclaved maize endosperm than germ. In contrast to a previous study, in which disruption of fst1 did not affect growth of the pathogen on autoclaved maize kernels, in the current study, we demonstrated that disruption of fst1 delayed growth and symptom development on wounded maize ears. Characterization of the fst1 promoter revealed that regulation of fst1 expression was similar to that of fumonisin biosynthetic (fum) genes; expression was highest during growth on endosperm tissue and repressed by elevated concentrations of ammonium in the growth medium. With a fluorescent tag attached to FST1, the protein localized transiently to the periphery of the cells near the plasma membrane and in vacuole-like structures, suggesting that membrane-localized FST1 was internalized and degraded in vacuoles. Expression of fst1 in a yeast strain lacking hexose transporter genes did not complement the yeast mutation, suggesting that FST1 does not transport glucose, fructose, or mannose. The results indicate a functional role for FST1 in pathogenesis during the colonization of living kernels.
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Affiliation(s)
- Hun Kim
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA
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Altinok HH. In vitro production of fumonisin B1 and B2 byFusarium moniliforme and the biocontrol activity ofTrichoderma harzianum. ANN MICROBIOL 2009. [DOI: 10.1007/bf03175139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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28
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Gao X, Kolomiets MV. Host-derived lipids and oxylipins are crucial signals in modulating mycotoxin production by fungi. TOXIN REV 2009. [DOI: 10.1080/15569540802420584] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kim H, Woloshuk CP. Role of AREA, a regulator of nitrogen metabolism, during colonization of maize kernels and fumonisin biosynthesis in Fusarium verticillioides. Fungal Genet Biol 2008; 45:947-53. [PMID: 18440841 DOI: 10.1016/j.fgb.2008.03.007] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 03/16/2008] [Accepted: 03/18/2008] [Indexed: 11/19/2022]
Abstract
Fumonisin B1 (FB(1)) biosynthesis is repressed in cultures containing ammonium as the nitrogen source and when grown on blister kernels, the earliest stages of kernel development. In this study AREA, a regulator of nitrogen metabolism, was disrupted in Fusarium verticilliodes. The mutant (DeltaareA) grew poorly on mature maize kernels, but grew similar to wild type (WT) with the addition of ammonium phosphate. FB(1) was not produced by DeltaareA under any condition or by the WT with added ammonium phosphate. Constitutive expression of AREA (strain AREA-CE) rescued the growth and FB(1) defects in DeltaareA. Growth of WT, DeltaareA, and AREA-CE on blister-stage kernels was similar. After 7 days of growth, none of the strains produced FB(1) and the pH of the kernel tissues was 8.0. Addition of amylopectin to the blister kernels resulted in a pH near 6.6 and FB(1) production by WT and AREA-CE. The results support the hypothesis that FB(1) biosynthesis is regulated by AREA. Also the failure to produce FB(1) in blister kernels is due to high pH conditions generated because of an unfavorable carbon/nitrogen environment.
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Affiliation(s)
- Hun Kim
- Department of Botany and Plant Pathology, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
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Bluhm BH, Kim H, Butchko RAE, Woloshuk CP. Involvement of ZFR1 of Fusarium verticillioides in kernel colonization and the regulation of FST1, a putative sugar transporter gene required for fumonisin biosynthesis on maize kernels. MOLECULAR PLANT PATHOLOGY 2008; 9:203-11. [PMID: 18705852 PMCID: PMC6640386 DOI: 10.1111/j.1364-3703.2007.00458.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Fumonisins comprise a class of carcinogenic mycotoxins produced by Fusarium verticillioides during colonization of maize kernels. In previous work, we identified ZFR1, which is predicted to encode a Zn(II)2Cys6 zinc finger transcription factor required for fumonisin B(1) (FB(1)) production during growth on kernels. In this study, we characterized the role of ZFR1 in colonizing maize kernels and inducing FB(1) biosynthesis. The ZFR1 deletion strain (Deltazfr1) grew approximately 2.5-fold less than the wild-type on endosperm tissue and a variety of other carbon sources, including glucose and amylopectin. However, the Deltazfr1 strain displayed higher alpha-amylase activity and expression of genes involved in starch saccharification than the wild-type, thus indicating that the reduced growth of the Deltazfr1 strain was not due to inhibition of amylolytic enzymes. In the wild-type strain, expression of six genes encoding putative sugar transporters was significantly greater on endosperm tissue than on germ tissue, and expression of at least three of the six genes was negatively affected by disruption of ZFR1. Intriguingly, disruption of FST1 had no effect on growth, kernel colonization or kernel pH but decreased FB(1) production by approximately 82% on maize kernels. Based on these findings, we hypothesize that ZFR1 controls FB(1) biosynthesis by regulating genes involved in the perception or uptake of carbohydrates.
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Affiliation(s)
- B H Bluhm
- Crop Production & Pest Control Research Unit, USDA-ARS, West Lafayette, IN 47907, USA
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Sagaram US, Shim WB. Fusarium verticillioides GBB1, a gene encoding heterotrimeric G protein beta subunit, is associated with fumonisin B biosynthesis and hyphal development but not with fungal virulence. MOLECULAR PLANT PATHOLOGY 2007; 8:375-384. [PMID: 20507507 DOI: 10.1111/j.1364-3703.2007.00398.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Fusarium verticillioides (Sacc.) Nirenberg (teleomorph Gibberella moniliformis Wineland) is a maize pathogen that causes ear rots and stalk rots. The fungus also produces a group of mycotoxins, fumonisins, on infected ears, which cause considerable health and economic concerns for humans and animals worldwide. To date, our understanding of the molecular mechanisms associated with fungal virulence and fumonisin biosynthesis in F. verticillioides is limited. In this study, GBB1, a gene encoding a putative beta subunit of a heterotrimeric G protein, was disrupted and the effects on fumonisin biosynthesis and virulence were evaluated. A GBB1 deletion mutant (Deltagbb1) showed no significant differences in radial growth and mycelial mass but produced significantly less fumonisin B(1 )(FB(1)) than its wild-type progenitor. HPLC analysis showed that Deltagbb1 produced less than 10 p.p.m. FB(1) while the wild-type produced over 140 p.p.m. when strains were grown on cracked corn kernels. Reduced expression of the key FB(1 )biosynthetic genes, FUM1 and FUM8, in Deltagbb1 provides further evidence that GBB1 is involved in FB(1) regulation. Stalk rot virulence, as measured by mean lesion length and by area, was not significantly different in Deltagbb1 compared with the wild-type, suggesting that GBB1 does not regulate virulence in F. verticillioides. Developmentally, hyphae of Deltagbb1 do not deviate from the original axis of polarity established upon germ tube emergence in contrast to wild-type hyphae that meander on and off axis as they grow. Complementation of Deltagbb1 with GBB1 restored FB(1) production and hyphal growth to wild-type. The results of this study demonstrate that heterotrimeric G protein beta subunit plays an important role in regulation of FB(1) biosynthesis and hyphal growth, but not virulence in F. verticillioides.
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Affiliation(s)
- Uma Shankar Sagaram
- Department of Plant Pathology and Microbiology, Program for the Biology of Filamentous Fungi, Texas A&M University, College Station, TX 77843-2132, USA
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Mansfield MA, Archibald DD, Jones AD, Kuldau GA. Relationship of sphinganine analog mycotoxin contamination in maize silage to seasonal weather conditions and to agronomic and ensiling practices. PHYTOPATHOLOGY 2007; 97:504-511. [PMID: 18943291 DOI: 10.1094/phyto-97-4-0504] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Sphinganine analog mycotoxins (SAMs) are reported in maize and maize based feeds. Our objectives were to detect and quantify fumonisins B(1) and B(2) and Alternaria toxins (AAL toxins) AAL-TA and AAL-TB and determine how agronomic practices, weather conditions, and ensiling affected the occurrence and levels in maize silage. Silage was collected at harvest and after ensiling in 2001 and 2002 from 30 to 40 dairies, representing four regions in Pennsylvania. SAMs were quantified using high pressure liquid chromatography (HPLC) with fluorescence detection and high pressure liquid chromatography-mass spectrometry HPLC-MS. The average concentrations and ranges were as follows: fumonisin B(1) 2.02 mug/g (0.20 to 10.10), fumonisin B(2) 0.98 mug/g (0.20 to 20.30), AAL-TA 0.17 mug/g (0.20 to 2.01), and AAL-TB 0.05 mug/g (0.03 to 0.90). Fumonisin B(1) was the most frequently detected toxin (92%) in all samples, followed by fumonisin B(2) (55%), AAL-TA (23%), and -TB (13%). Temperature during maize development was positively correlated with fumonisin occurrence and levels and negatively with AAL-TA, while moisture events were negatively correlated with fumonisins and positively with AAL-TA. Fumonisin levels were higher in silage harvested at later developmental stages (dough through physiological maturity). Ensiling did not affect toxin concentration nor did agronomic practices (tillage system, inoculant use, or silo type) or silage characteristics (dry matter, pH, or organic acid concentration). This is the first report of AAL-TB in silage and on factors that affect SAM frequency and levels in maize silage.
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Sagaram US, Butchko RAE, Shim WB. The putative monomeric G-protein GBP1 is negatively associated with fumonisin B production in Fusarium verticillioides. MOLECULAR PLANT PATHOLOGY 2006; 7:381-389. [PMID: 20507454 DOI: 10.1111/j.1364-3703.2006.00347.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Fumonisin B(1) (FB(1)) is a mycotoxin produced by Fusarium verticillioides that contaminates maize. FB(1) has been linked to a number of human and animal mycotoxicoses worldwide. Despite its significance, our understanding of the FB(1) biosynthesis regulatory mechanisms is limited. Here, we describe F. verticillioides GBP1, encoding a monomeric G-protein, and its role in FB(1) biosynthesis. GBP1 was discovered as an expressed sequence tag (EST) up-regulated in the F. verticillioides fcc1 mutant that showed reduced conidiation and no FB(1) biosynthesis when grown on maize kernels. Sequence analysis showed that GBP1 encodes a putative 368-amino-acid protein with similarity to DRG and Obg subclasses of G-proteins that are involved in development and stress responses. A GBP1 knockout mutant (Deltagbp1) exhibited normal growth, but increased FB(1) production (> 58%) compared with the wild-type when grown on corn kernels. Complementation of Deltagbp1 with the wild-type GBP1 gene restored FB(1) production levels to that of the wild-type. Our data indicate that GBP1 is negatively associated with FB(1) biosynthesis but not with conidiation in F. verticillioides. The deletion of GBP1 led to up-regulation of key FB(1) biosynthetic genes, FUM1 and FUM8, suggesting that the increased FB(1) production in Deltagbp1 is due to over-expression of FUM genes.
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Affiliation(s)
- Uma Shankar Sagaram
- Department of Plant Pathology and Microbiology, Program for the Biology of Filamentous Fungi, Texas A&M University, College Station, TX 77843-2132, USA
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Brodhagen M, Keller NP. Signalling pathways connecting mycotoxin production and sporulation. MOLECULAR PLANT PATHOLOGY 2006; 7:285-301. [PMID: 20507448 DOI: 10.1111/j.1364-3703.2006.00338.x] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
SUMMARY Mycotoxin contamination of food and feed presents a serious food safety issue on a global scale, causing tremendous yield and economic losses. These toxins, produced largely by members of the genera Aspergillus and Fusarium, represent a subset of the impressive array of secondary metabolites produced by filamentous fungi. Some secondary metabolites are associated temporally and functionally with sporulation. In Aspergillus and Fusarium, sporulation and mycotoxin production are both regulated by G protein signalling pathways. G protein signalling pathways commonly regulate fungal development, stress response and expression of virulence traits. In addition, fungal development is influenced by external factors. Among these are lipids, and in particular, oxylipin signals, which may be derived from either the fungus or infected seeds. Regardless of origin, oxylipins have the potential to elicit profound changes in both sporulation and mycotoxin production in the fungus. Signal transduction via G protein signalling pathways represents one mechanism by which oxylipin signals might elicit these changes. Therefore, in this review we integrate discussion of oxylipin signals and of G protein signalling cascades as regulators of fungal development.
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Affiliation(s)
- Marion Brodhagen
- Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Dr, Madison, WI 53706-1598, USA
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Bluhm BH, Woloshuk CP. Amylopectin induces fumonisin B1 production by Fusarium verticillioides during colonization of maize kernels. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2005; 18:1333-9. [PMID: 16478053 DOI: 10.1094/mpmi-18-1333] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Fusarium verticillioides, a fungal pathogen of maize, produces fumonisin mycotoxins that adversely affect human and animal health. Basic questions remain unanswered regarding the interactions between the host plant and the fungus that lead to the accumulation of fumonisins in maize kernels. In this study, we evaluated the role of kernel endosperm composition in regulating fumonisin B1 (FB1) biosynthesis. We found that kernels lacking starch due to physiological immaturity did not accumulate FB1. Quantitative polymerase chain reaction analysis indicated that kernel development also affected the expression of fungal genes involved in FB1 biosynthesis, starch metabolism, and nitrogen regulation. A mutant strain of F. verticillioides with a disrupted a-amylase gene was impaired in its ability to produce FB1 on starchy kernels, and both the wild-type and mutant strains produced significantly less FB1 on a high-amylose kernel mutant of maize. When grown on a defined medium with amylose as the sole carbon source, the wild-type strain produced only trace amounts of FB1, but it produced large amounts of FB1 when grown on amylopectin or dextrin, a product of amylopectin hydrolysis. We conclude that amylopectin induces FB1 production in F. verticillioides. This study provides new insight regarding the interaction between the fungus and maize kernel during pathogenesis and highlights important areas that need further study.
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Affiliation(s)
- B H Bluhm
- Department of Botany and Plant Pathology, Purdue University, 915 W. State Street, West Lafayette, IN 47907, USA
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Flaherty JE, Woloshuk CP. Regulation of fumonisin biosynthesis in Fusarium verticillioides by a zinc binuclear cluster-type gene, ZFR1. Appl Environ Microbiol 2004; 70:2653-9. [PMID: 15128515 PMCID: PMC404460 DOI: 10.1128/aem.70.5.2653-2659.2004] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Fusarium verticillioides, a pathogen of maize, produces a class of mycotoxins called fumonisins in infected kernels. In this study, a candidate regulatory gene, ZFR1, was identified in an expressed sequence tag library enriched for transcripts expressed by F. verticillioides during fumonisin B(1) (FB(1)) biosynthesis. ZFR1 deletion mutants exhibited normal growth and development on maize kernels, but fumonisin production was reduced to less than 10% of that of the wild-type strain. ZFR1 encodes a putative protein of 705 amino acids with sequence similarity to the Zn(II)2Cys6 binuclear cluster family that are regulators of both primary and secondary metabolism in fungi. Expression of ZFR1 in colonized germ and degermed kernel tissues correlated with FB(1) levels. Overexpression of ZFR1 in zfr1 mutants restored FB(1) production to wild-type levels; however, FB(1) was not restored in an fcc1 (Fusarium C-type cyclin) mutant by overexpression of ZFR1. The results of this study indicate that ZFR1 is a positive regulator of FB(1) biosynthesis in F. verticillioides and suggest that FCC1 is required for ZFR1 function.
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Affiliation(s)
- Joseph E Flaherty
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana 47907-2054, USA
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