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Koizumi Y, Nakajima Y, Tanaka Y, Matsui K, Sakabe M, Maeda K, Sato M, Koshino H, Sato S, Kimura M, Takahashi-Ando N. A Role in 15-Deacetylcalonectrin Acetylation in the Non-Enzymatic Cyclization of an Earlier Bicyclic Intermediate in Fusarium Trichothecene Biosynthesis. Int J Mol Sci 2024; 25:4288. [PMID: 38673874 PMCID: PMC11050026 DOI: 10.3390/ijms25084288] [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: 03/22/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 04/28/2024] Open
Abstract
The trichothecene biosynthesis in Fusarium begins with the cyclization of farnesyl pyrophosphate to trichodiene, followed by subsequent oxygenation to isotrichotriol. This initial bicyclic intermediate is further cyclized to isotrichodermol (ITDmol), a tricyclic precursor with a toxic trichothecene skeleton. Although the first cyclization and subsequent oxygenation are catalyzed by enzymes encoded by Tri5 and Tri4, the second cyclization occurs non-enzymatically. Following ITDmol formation, the enzymes encoded by Tri101, Tri11, Tri3, and Tri1 catalyze 3-O-acetylation, 15-hydroxylation, 15-O-acetylation, and A-ring oxygenation, respectively. In this study, we extensively analyzed the metabolites of the corresponding pathway-blocked mutants of Fusarium graminearum. The disruption of these Tri genes, except Tri3, led to the accumulation of tricyclic trichothecenes as the main products: ITDmol due to Tri101 disruption; a mixture of isotrichodermin (ITD), 7-hydroxyisotrichodermin (7-HIT), and 8-hydroxyisotrichodermin (8-HIT) due to Tri11 disruption; and a mixture of calonectrin and 3-deacetylcalonectrin due to Tri1 disruption. However, the ΔFgtri3 mutant accumulated substantial amounts of bicyclic metabolites, isotrichotriol and trichotriol, in addition to tricyclic 15-deacetylcalonectrin (15-deCAL). The ΔFgtri5ΔFgtri3 double gene disruptant transformed ITD into 7-HIT, 8-HIT, and 15-deCAL. The deletion of FgTri3 and overexpression of Tri6 and Tri10 trichothecene regulatory genes did not result in the accumulation of 15-deCAL in the transgenic strain. Thus, the absence of Tri3p and/or the presence of a small amount of 15-deCAL adversely affected the non-enzymatic second cyclization and C-15 hydroxylation steps.
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Affiliation(s)
- Yoshiaki Koizumi
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
| | - Yuichi Nakajima
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Yuya Tanaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Kosuke Matsui
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Masato Sakabe
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
| | - Kazuyuki Maeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
| | - Masayuki Sato
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Hiroyuki Koshino
- Molecular Structure Characterization Unit, Technology Platform Division, Center for Sustainable Resource Science (CSRS) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Soichi Sato
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
| | - Makoto Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan; (Y.N.); (Y.T.); (K.M.); (K.M.)
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
| | - Naoko Takahashi-Ando
- Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan; (Y.K.); (S.S.)
- Faculty of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe 350-8585, Japan;
- Plant & Microbial Engineering Research Unit, Discovery Research Institute (DRI) RIKEN, 2-1 Hirosawa, Wako 351-0198, Japan;
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Liew MXX, Nakajima Y, Maeda K, Kitamura N, Kimura M. Regulatory mechanism of trichothecene biosynthesis in Fusarium graminearum. Front Microbiol 2023; 14:1148771. [PMID: 37138602 PMCID: PMC10149712 DOI: 10.3389/fmicb.2023.1148771] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/24/2023] [Indexed: 05/05/2023] Open
Abstract
Among the genes involved in the biosynthesis of trichothecene (Tri genes), Tri6 and Tri10 encode a transcription factor with unique Cys2His2 zinc finger domains and a regulatory protein with no consensus DNA-binding sequences, respectively. Although various chemical factors, such as nitrogen nutrients, medium pH, and certain oligosaccharides, are known to influence trichothecene biosynthesis in Fusarium graminearum, the transcriptional regulatory mechanism of Tri6 and Tri10 genes is poorly understood. Particularly, culture medium pH is a major regulator in trichothecene biosynthesis in F. graminearum, but it is susceptible to metabolic changes posed by nutritional and genetic factors. Hence, appropriate precautions should be considered to minimize the indirect influence of pH on the secondary metabolism while studying the roles of nutritional and genetic factors on trichothecene biosynthesis regulation. Additionally, it is noteworthy that the structural changes of the trichothecene gene cluster core region exert considerable influence over the normal regulation of Tri gene expression. In this perspective paper, we consider a revision of our current understanding of the regulatory mechanism of trichothecene biosynthesis in F. graminearum and share our idea toward establishing a regulatory model of Tri6 and Tri10 transcription.
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Impact of nitrogen metabolism-associated culture pH changes on regulation of Fusarium trichothecene biosynthesis: revision of roles of polyamine agmatine and transcription factor AreA. Curr Genet 2020; 66:1179-1190. [PMID: 32812074 DOI: 10.1007/s00294-020-01102-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/04/2020] [Accepted: 08/06/2020] [Indexed: 10/23/2022]
Abstract
Fusarium graminearum produces trichothecene mycotoxins in infected grains and axenic liquid culture. A proposed regulatory model of trichothecene biosynthesis was examined in relation to nitrogen utilization. First, we showed that an important factor for the stimulation of trichothecene biosynthesis was not the occurrence of agmatine as a specific inducer molecule, but rather continuous acidification of the liquid culture medium arising from agmatine catabolism. When the pH of the L-Gln synthetic medium was frequently adjusted to the pH of the agmatine culture, trichothecene productivity of the L-Gln culture was equal to that of the agmatine culture. For efficient trichothecene biosynthesis, the culture pH should be lowered at an appropriate time point during the early growth stage. Second, we re-evaluated the role of the nitrogen regulatory GATA transcription factor AreA in trichothecene biosynthesis. Since Tri6 encodes a transcription factor indispensable for trichothecene biosynthesis, all fifteen AreA-binding consensus sequences in the Tri6 promoter were mutated. The mutant could catabolize L-Phe as the sole nitrogen source; furthermore, the pH profile of the synthetic L-Phe medium (initial pH 4.2) was the same as that of the wild-type (WT) strain. Under such conditions, the promoter mutant exhibited approximately 72% of the trichothecene productivity compared to the WT strain. Thus, F. graminearum AreA (FgAreAp) is dispensable for the functioning of the Tri6 promoter, but it contributes to the increased production of mycotoxin under mildly acidic conditions to some extent. Further investigations on the culture pH revealed that extremely low pH bypasses the function of FgAreAp.
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Hay WT, McCormick SP, Hojilla-Evangelista MP, Bowman MJ, Dunn RO, Teresi JM, Berhow MA, Vaughan MM. Changes in Wheat Nutritional Content at Elevated [CO 2] Alter Fusarium graminearum Growth and Mycotoxin Production on Grain. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:6297-6307. [PMID: 32407107 DOI: 10.1021/acs.jafc.0c01308] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rising atmospheric [CO2] has been shown to impact plant primary metabolism and the severity of Fusarium head blight (FHB) in wheat. In this study, we evaluated how changes in grain nutritional content due to growth at elevated [CO2] affected Fusarium graminearum growth and mycotoxin production. Susceptible (Norm) and moderately resistant (Alsen) hard spring wheat grains that had been grown at ambient (400 ppm) or elevated [CO2] (800 ppm) were independently inoculated with two F. graminearum fungal strains, which produce the trichothecene mycotoxin, deoxynivalenol. Under higher [CO2], FHB-susceptible and moderately resistant wheat had disproportionate losses in protein and mineral contents, with Alsen being more severely impacted. Furthermore, the F. graminearum strain 9F1 had increased mycotoxin biosynthesis in response to the loss of wheat nutritional content in Alsen. Our results demonstrate that future [CO2] conditions may provide a strain-specific pathogenic advantage on hosts, with greater losses in nutritional content.
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Affiliation(s)
- William T Hay
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Susan P McCormick
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Milagros P Hojilla-Evangelista
- Plant Polymer Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Michael J Bowman
- Bioenergy Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Robert O Dunn
- Bio-oils Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Jennifer M Teresi
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
| | - Mark A Berhow
- Functional Foods Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, Peoria, Illinois 61604, United States
| | - Martha M Vaughan
- Mycotoxin Prevention and Applied Microbiology Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, USDA, 1815 North, University Street, Peoria, Illinois 61604, United States
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Bitchagno GTM, Schüffler A, Simo IK, Krumb M, Tane P, Opatz T. Neo-clerodane diterpenoids from Conyza pyrrhopappa Sch.Bip. ex A.Rich. Nat Prod Res 2019; 35:3210-3219. [PMID: 31726857 DOI: 10.1080/14786419.2019.1690490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Two hitherto unknown neo-clerodane-type diterpenoids along with twelve known compounds have been isolated from Conyza pyrrhopappa Sch.Bip. ex A.Rich, a medicinal plant traditionally used across tropical Africa to relieve fever. The structures of isolates have been elucidated by a combination of spectroscopic techniques. The crude extract and the isolated compounds were evaluated in the Hela-S3 cell line and in a panel of microorganisms (bacteria and fungi) at concentrations up to 50 µg/mL. The new compounds were inactive while the pentamethylated flavonoids showed low to significant activity against the cancer cell line used. However, none of the samples showed any activity against the tested microorganisms at this concentration. The present manuscript is the first investigation of the cytotoxicity of phytochemicals and extract from C. pyrrhopappa.
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Affiliation(s)
- Gabin Thierry M Bitchagno
- Department of Chemistry, University of Dschang, Dschang, Cameroon.,Institute of Organic Chemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Anja Schüffler
- Institut für Biotechnologie und Wirkstoff-Forschung gGmbH (IBWF), Kaiserslautern, Germany
| | - Ingrid K Simo
- Department of Chemistry, University of Dschang, Dschang, Cameroon
| | - Matthias Krumb
- Institute of Organic Chemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Pierre Tane
- Department of Chemistry, University of Dschang, Dschang, Cameroon
| | - Till Opatz
- Institute of Organic Chemistry, Johannes Gutenberg-University of Mainz, Mainz, Germany
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Tanaka Y, Nakajima Y, Maeda K, Matsuyama M, Kanamaru K, Kobayashi T, Ohsato S, Kimura M. Inhibition of Fusarium trichothecene biosynthesis by yeast extract components extractable with ethyl acetate. Int J Food Microbiol 2019; 289:24-29. [DOI: 10.1016/j.ijfoodmicro.2018.08.026] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 08/16/2018] [Accepted: 08/24/2018] [Indexed: 11/28/2022]
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Song X, Gu K, Duan X, Xiao X, Hou Y, Duan Y, Wang J, Yu N, Zhou M. Secondary amplification of siRNA machinery limits the application of spray-induced gene silencing. MOLECULAR PLANT PATHOLOGY 2018; 19:2543-2560. [PMID: 30027625 PMCID: PMC6638038 DOI: 10.1111/mpp.12728] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Spray-induced gene silencing (SIGS) is an innovative strategy for crop protection. However, the mechanism of SIGS is not known. Here, we first demonstrate that secondary small interfering RNA (siRNA) amplification limits the application of SIGS. A myosin5 gene (Myo5) was chosen as the target of SIGS in an agronomically important pathogen-Fusarium asiaticum. Five segments corresponding to the different regions of the Myo5 gene were found to efficiently silence Myo5, resulting in cell wall defects, life cycle disruption and virulence reduction. Myo5-8 (one of the Myo5 segments) induced sequence-specific RNA interference (RNAi) activity in F. asiaticum, F. graminearum, F. tricinctum and F. oxysporum, but not in other fungi, in vitro. Remarkably, the silencing of Myo5 lasted for only 9 h unless the double-stranded RNA (dsRNA) was continuously supplied, because F. asiaticum is unable to maintain siRNA amplification. After spraying on plants, dsRNAs were more efficiently taken up via the wounded surface. The antifungal activity of dsRNAs taken up by plant cells was higher and longer lasting than that dried onto the plant surface. In contrast with dsRNAs in fungi, dsRNAs in plant cells could efficiently turn into substantial siRNAs via secondary amplification machinery. Our findings provide new implications to develop SIGS as a mainstream disease control strategy against Fusarium and other fungi.
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Affiliation(s)
- Xiu‐Shi Song
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Kai‐Xin Gu
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Xiao‐Xin Duan
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Xue‐Mei Xiao
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Yi‐Ping Hou
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Ya‐Bing Duan
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Jian‐Xin Wang
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Na Yu
- Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
| | - Ming‐Guo Zhou
- Key Laboratory of Pesticide, College of Plant ProtectionNanjing Agricultural UniversityNanjingJiangsu Province210095China
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Shiobara T, Nakajima Y, Maeda K, Akasaka M, Kitou Y, Kanamaru K, Ohsato S, Kobayashi T, Nishiuchi T, Kimura M. Identification of amino acids negatively affecting Fusarium trichothecene biosynthesis. Antonie Van Leeuwenhoek 2018; 112:471-478. [PMID: 30267234 DOI: 10.1007/s10482-018-1172-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 09/23/2018] [Indexed: 10/28/2022]
Abstract
Nitrogen sources in media have a significant impact on the onset of secondary metabolism in fungi. For transcriptional activation of many nitrogen catabolic genes, an AreA transcription factor is indispensable. This also holds true for Fusarium graminearum that produces trichothecenes, an important group of mycotoxin, in axenic culture. Despite the presence of numerous consensus AreA-binding sites in the promoters of Tri genes in the trichothecene cluster core region, the effect of medium amino acids on trichothecene biosynthesis is poorly understood. In this study, we examined the effect of certain amino acids, which were predicted to activate AreA function and increase Tri gene transcription, on trichothecene production in liquid culture. By frequent monitoring and adjustments in the pH of the culture medium, including replacement of the spent medium with fresh medium, we demonstrate the suppressive effects of the amino acids, used as the sole nitrogen source, on trichothecene biosynthesis. When the medium pH was maintained at 4.0, Gly, L-Ser, and L-Thr suppressed trichothecene production by F. graminearum. Enhanced trichothecene-inducing effects were observed when the medium pH was 3.5, with only L-Thr suppressing trichothecene synthesis.
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Affiliation(s)
- Takuya Shiobara
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Yuichi Nakajima
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Kazuyuki Maeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Kawasaki, Kanagawa, 214-8571, Japan
| | - Manami Akasaka
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Yoshiyuki Kitou
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Kyoko Kanamaru
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Shuichi Ohsato
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Kawasaki, Kanagawa, 214-8571, Japan
| | - Tetsuo Kobayashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan
| | - Takumi Nishiuchi
- Advanced Science Research Centre, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa, 920-0934, Japan
| | - Makoto Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601, Japan.
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Maeda K, Ichikawa H, Nakajima Y, Motoyama T, Ohsato S, Kanamaru K, Kobayashi T, Nishiuchi T, Osada H, Kimura M. Identification and Characterization of Small Molecule Compounds That Modulate Trichothecene Production by Fusarium graminearum. ACS Chem Biol 2018; 13:1260-1269. [PMID: 29565558 DOI: 10.1021/acschembio.8b00044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
From the RIKEN Natural Products Depository (NPDepo) chemical library, we identified small molecules that alter trichothecene 15-acetyldeoxynivalenol (15-ADON) production by Fusarium graminearum. Among trichothecene production activators, a furanocoumarin NPD12671 showed the strongest stimulatory activity on 15-ADON production by the fungus cultured in a 24-well plate. NPD12671 significantly increased the transcription of Tri6, a transcription factor gene necessary for trichothecene biosynthesis, in both trichothecene-inducing and noninducing culture conditions. Dihydroartemisinin (DHA) was identified as the most effective inhibitor of trichothecene production in 24-well plate culture; DHA inhibited trichothecene production (>50% inhibition at 1 μM) without affecting fungal mass by suppressing Tri6 expression. To determine the effect of DHA on trichothecene pathway Tri gene expression, we generated a constitutively Tri6-overexpressing strain that produced 15-ADON in YG_60 medium in Erlenmeyer flasks, conditions under which no trichothecenes are produced by the wild-type. While 5 μM DHA failed to inhibit trichothecene biosynthesis by the overexpressor in trichothecene-inducing YS_60 culture, trichothecene production was suppressed in the YG_60 culture. Regardless of a high Tri6 transcript level in the constitutive overexpressor, the YG_60 culture showed reduced accumulation of Tri5 and Tri4 mRNA upon treatment with 5 μM DHA. Deletion mutants of FgOs2 were also generated and examined; both NPD12671 and DHA modulated trichothecene production as they did in the wild-type strain. These results are discussed in light of the mode of actions of these chemicals on trichothecene biosynthesis.
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Affiliation(s)
- Kazuyuki Maeda
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Kawasaki, Kanagawa 214-8571, Japan
| | - Hinayo Ichikawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Yuichi Nakajima
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Takayuki Motoyama
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Shuichi Ohsato
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Kawasaki, Kanagawa 214-8571, Japan
| | - Kyoko Kanamaru
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Tetsuo Kobayashi
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Takumi Nishiuchi
- Advanced Science Research Centre, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-0934, Japan
| | - Hiroyuki Osada
- Chemical Biology Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Makoto Kimura
- Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
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Maeda K, Nakajima Y, Motoyama T, Kondoh Y, Kawamura T, Kanamaru K, Ohsato S, Nishiuchi T, Yoshida M, Osada H, Kobayashi T, Kimura M. Identification of a trichothecene production inhibitor by chemical array and library screening using trichodiene synthase as a target protein. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2017; 138:1-7. [PMID: 28456298 DOI: 10.1016/j.pestbp.2017.03.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/20/2017] [Accepted: 03/21/2017] [Indexed: 06/07/2023]
Abstract
Trichothecene mycotoxins often accumulate in apparently normal grains of cereal crops. In an effort to develop an agricultural chemical to reduce trichothecene contamination, we screened trichothecene production inhibitors from the compounds on the chemical arrays. By using the trichodiene (TDN) synthase tagged with hexahistidine (rTRI5) as a target protein, 32 hit compounds were obtained from chemical library of the RIKEN Natural Product Depository (NPDepo) by chemical array screening. At 10μgmL-1, none of the 32 chemicals inhibited trichothecene production by Fusarium graminearum in liquid culture. Against the purified rTRI5 enzyme, however, NPD10133 [progesterone 3-(O-carboxymethyl)oxime amide-bonded to phenylalanine] showed weak inhibitory activity at 10μgmL-1 (18.7μM). For the screening of chemicals inhibiting trichothecene accumulation in liquid culture, 20 analogs of NPD10133 selected from the NPDepo chemical library were assayed. At 10μM, only NPD352 [testosterone 3-(O-carboxymethyl)oxime amide-bonded to phenylalanine methyl ester] inhibited rTRI5 activity and trichothecene production. Kinetic analysis suggested that the enzyme inhibition was of a mixed-type. The identification of NPD352 as a TDN synthase inhibitor lays the foundation for the development of a more potent inhibitor via systematic introduction of wide structural diversity on the gonane skeleton and amino acid residues.
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Affiliation(s)
- Kazuyuki Maeda
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan; Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
| | - Yuichi Nakajima
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan; Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takayuki Motoyama
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yasumitsu Kondoh
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tatsuro Kawamura
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Kyoko Kanamaru
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Shuichi Ohsato
- Graduate School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa 214-8571, Japan
| | - Takumi Nishiuchi
- Division of Functional Genomics, Advanced Science Research Centre, Kanazawa University, 13-1 Takaramachi, Kanazawa, Ishikawa 920-0934, Japan
| | - Minoru Yoshida
- Chemical Genetics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroyuki Osada
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Tetsuo Kobayashi
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan
| | - Makoto Kimura
- Department of Biological Mechanisms and Functions, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8601, Japan.
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L-Threonine and its analogue added to autoclaved solid medium suppress trichothecene production by Fusarium graminearum. Arch Microbiol 2017; 199:945-952. [PMID: 28357472 DOI: 10.1007/s00203-017-1364-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/18/2016] [Accepted: 03/15/2017] [Indexed: 12/30/2022]
Abstract
Fusarium graminearum produces trichothecene mycotoxins under certain nutritional conditions. When L-Thr and its analogue L-allo-threonine were added to brown rice flour solid medium before inoculation, trichothecene production after 4 days of incubation was suppressed. A time-course analysis of gene expression demonstrated that L-Thr suppressed transcription of Tri6, a trichothecene master regulator gene, and a terpene cyclase Tri5 gene. Regulation of trichothecene biosynthesis by altering major primary metabolic processes may open up the possibility to develop safe chemicals for the reduction of mycotoxin contamination might be developed.
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