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Zhang C, Zhao C, Zheng H, Li L, Zheng Y, Wu Z. Design, Synthesis, and Study of the Dual Action Mode of Novel N-Thienyl-1,5-disubstituted-4-pyrazole Carboxamides against Nigrospora oryzae. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7210-7220. [PMID: 37141153 DOI: 10.1021/acs.jafc.3c00269] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Due to the single target but extensive application of commercialized succinate dehydrogenase inhibitors (SDHIs), resistance problems have gradually become apparent in recent years. To solve this problem, a series of novel N-thienyl-1,5-disubstituted-1H-4-pyrazole carboxamide derivatives were designed and synthesized in this work based on the active skeleton 5-trifluoromethyl-4-pyrazole carboxamide. The bioassay results indicated that some target compounds exhibited excellent in vitro antifungal activities against the eight phytopathogenic fungi tested. Among them, the EC50 values of T4, T6, and T9 against Nigrospora oryzae were 5.8, 1.9, and 5.5 mg/L, respectively. The in vivo protective and curative activities of 40 mg/L T6 against rice infected with N. oryzae were 81.5% and 43.0%, respectively. Further studies revealed that T6 not only significantly inhibited the growth of N. oryzae mycelia but also effectively hindered spore germination and germ tube elongation. Morphological studies using scanning electron microscopy (SEM), fluorescence microscopy (FM), and transmission electron microscopy (TEM) found that T6 could affect the mycelium membrane integrity by increasing cell membrane permeability and causing peroxidation of cellular lipids, and these results were further verified by measuring the malondialdehyde (MDA) content. The IC50 value of T6 against succinate dehydrogenase (SDH) was 7.2 mg/L, lower than that of the commercialized SDHI penthiopyrad (3.4 mg/L). Further, ATP content detection and the results after docking T6 and penthiopyrad suggested that T6 was a potential SDHI. These studies demonstrated that active compound T6 could both inhibit the activity of SDH and affect the integrity of the cell membrane at the same time via a dual action mode, which is different from the mode of action of penthiopyrad. Thus, this study provides a new idea for a strategy to delay resistance and diversify the structures of SDHIs.
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Affiliation(s)
- Chengzhi Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
| | - Cailong Zhao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
| | - Huanlin Zheng
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
| | - Longju Li
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
| | - Ya Zheng
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
| | - Zhibing Wu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, 550025, China
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Wu L, Wu Z, Zhao F, Hahn M, Zhou M, Hou Y. Activity and cell toxicology of fluazinam on Fusarium graminearum. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2022; 188:105253. [PMID: 36464359 DOI: 10.1016/j.pestbp.2022.105253] [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: 06/13/2022] [Revised: 09/17/2022] [Accepted: 09/20/2022] [Indexed: 06/17/2023]
Abstract
Fusarium graminearum is an important plant pathogen and the causal agent of Fusarium head blight (FHB). At present, the principal method of controlling FHB is through fungicides. Fluazinam is an agent with strong broad-spectrum antifungal activity and has been used to control many diseases. However, there are no reported uses of fluazinam for controlling FHB. This study reports the activity and cell toxicology mechanisms of fluazinam on the filamentous fungus F. graminearum and its effect on fungal growth and development. The activity of fluazinam was tested for 95 wild-type field strains of F. graminearum. The EC50 values (the 50% effective concentration) of fluazinam for inhibition of mycelial growth and spore germination ranged from 0.037 μg/ml to 0.179 μg/ml and from 0.039 μg/ml to 0.506 μg/ml, respectively. The fluazinam sensitivity of these strains varied in 4.9 and 13.0 folds, implying that the target of the fungicide remained unchanged. After treatment with 0.3 μg/ml (≈EC90) fluazinam, the production of conidia was reduced, and the cell wall and cell membrane had shrunked; the cell nucleus and septum morphology, cell membrane permeability, and sexual development were not affected. When treated with 0.1 μg/ml (≈EC50) or 0.3 μg/ml fluazinam, the mycelial respiration and deoxynivalenol (DON) synthesis of F. graminearum were decreased. Confocal images showed that the formation of toxisomes was disturbed after fluazinam treatment, suggesting that fluazinam reduces DON synthesis by inhibiting toxisome formation. Infection of wheat coleoptiles revealed that fluazinam had a strong protective activity against F. graminearum. At 250 μg/ml fluazinam the control efficacy of protective treatments reached 100% and controlled strains resistant to carbendazim. These results contribute to the understanding of the mode of action of fluazinam and its application.
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Affiliation(s)
- Luoyu Wu
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Pesticide, Nanjing, Jiangsu Province 210095, China
| | - Zhiwen Wu
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Pesticide, Nanjing, Jiangsu Province 210095, China
| | - Feifei Zhao
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Pesticide, Nanjing, Jiangsu Province 210095, China
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, Germany
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Pesticide, Nanjing, Jiangsu Province 210095, China.
| | - Yiping Hou
- College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Pesticide, Nanjing, Jiangsu Province 210095, China.
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Cheng X, Dai T, Hu Z, Cui T, Wang W, Han P, Hu M, Hao J, Liu P, Liu X. Cytochrome P450 and Glutathione S-Transferase Confer Metabolic Resistance to SYP-14288 and Multi-Drug Resistance in Rhizoctonia solani. Front Microbiol 2022; 13:806339. [PMID: 35387083 PMCID: PMC8977892 DOI: 10.3389/fmicb.2022.806339] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/26/2022] [Indexed: 11/17/2022] Open
Abstract
SYP-14288 is a fungicide as an uncoupler of oxidative phosphorylation, which is effective in controlling fungal pathogens like Rhizoctonia solani. To determine whether R. solani can develop SYP-14288 resistance and possibly multi-drug resistance (MDR), an SYP-14288-resistant mutant of R. solani X19-7 was generated from wild-type strain X19, and the mechanism of resistance was studied through metabolic and genetic assays. From metabolites of R. solani treated with SYP-14288, three compounds including M1, M2, and M3 were identified according to UPLC-MS/MS analysis, and M1 accumulated faster than M2 and M3 in X19-7. When X19-7 was treated by glutathione-S-transferase (GST) inhibitor diethyl maleate (DEM) and SYP-14288 together, or by DEM plus one of tested fungicides that have different modes of action, a synergistic activity of resistance occurred, implying that GSTs promoted metabolic resistance against SYP-14288 and therefore led to MDR. By comparing RNA sequences between X19-7 and X19, six cytochrome P450s (P450s) and two GST genes were selected as a target, which showed a higher expression in X19-7 than X19 both before and after the exposure to SYP-14288. Furthermore, heterologous expression of P450 and GST genes in yeast was conducted to confirm genes involved in metabolic resistance. In results, the P450 gene AG1IA_05136 and GST gene AG1IA_07383 were related to fungal resistance to multiple fungicides including SYP-14288, fluazinam, chlorothalonil, and difenoconazole. It was the first report that metabolic resistance of R. solani to uncouplers was associated with P450 and GST genes.
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Affiliation(s)
- Xingkai Cheng
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Tan Dai
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Zhihong Hu
- Institute of Quality Standard and Testing Technology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Tongshan Cui
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Weizhen Wang
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Ping Han
- Institute of Quality Standard and Testing Technology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, China
| | - Maolin Hu
- Shenzhen Agricultural Technology Promotion Center, Shenzhen, China
| | - Jianjun Hao
- School of Food and Agriculture, University of Maine, Orono, ME, United States
| | - Pengfei Liu
- Department of Plant Pathology, China Agricultural University, Beijing, China
| | - Xili Liu
- Department of Plant Pathology, China Agricultural University, Beijing, China
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