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Ou M, Hu K, Li M, Zhang X, Lu X, Zhan X, Liao X, Zhao Q, Li M, Li R. Resistance Risk Assessment of Propiconazole in Rhizoctonia solani and its Synergistic Antifungal Mechanism with Kresoxim-methyl. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2025. [PMID: 40389827 DOI: 10.1021/acs.jafc.5c02319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2025]
Abstract
The resistance risk and mechanisms of propiconazole in Rhizoctonia solani remain unclear. In this study, the sensitivity of 159 R. solani isolates to propiconazole was determined, and the EC50 value was 0.2286 μg/mL. Nineteen propiconazole-resistant mutants of R. solani were obtained through fungicide adaptation, and the compound fitness indexes of these propiconazole-resistant mutants were lower than those of their parental isolates. Cross-resistance analysis revealed that there was no cross-resistance between propiconazole and other fungicides, apart from prochloraz. Although no point mutations occurred in the RsCYP51 gene or its promoter regions, the expression levels of RsCYP51 and efflux transporter genes increased substantially in the propiconazole-resistant mutants. Furthermore, a 1:1 synergistic combination of propiconazole and kresoxim-methyl (SCpk(1:1)) could simultaneously cause more severe damage to both cell membrane integrity and mitochondrial function. Field trials demonstrated that SCpk(1:1) achieved over 86% control efficacy against rice sheath blight applied at 120 g a.i./ha.
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Affiliation(s)
- Minggui Ou
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Ke Hu
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Min Li
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Xinchun Zhang
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Xuemei Lu
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Xingyu Zhan
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Xun Liao
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
- Guizhou Key Laboratory of Agricultural Biosecurity/Provincial Key Laboratory for Agricultural Pest Management in Mountainous Region, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Quanzhi Zhao
- Institute of Rice Industrial Technology Research, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Ming Li
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
- Guizhou Key Laboratory of Agricultural Biosecurity/Provincial Key Laboratory for Agricultural Pest Management in Mountainous Region, Guizhou University, Guiyang 550025, Guizhou P. R. China
| | - Rongyu Li
- Institute of Crop Protection, Guizhou University, Guiyang 550025, Guizhou P. R. China
- Guizhou Key Laboratory of Agricultural Biosecurity/Provincial Key Laboratory for Agricultural Pest Management in Mountainous Region, Guizhou University, Guiyang 550025, Guizhou P. R. China
- Institute of Rice Industrial Technology Research, Guizhou University, Guiyang 550025, Guizhou P. R. China
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Zhao W, Chen Z, Fu W, Ye C, Fu H, Xu T, Wu B, Chen L, Shan SJ. Induction of apoptosis and hypoxic stress in malignant melanoma cells via graphene-mediated far-infrared radiation. BMC Cancer 2025; 25:620. [PMID: 40197161 PMCID: PMC11974076 DOI: 10.1186/s12885-025-14031-0] [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: 02/08/2025] [Accepted: 03/27/2025] [Indexed: 04/10/2025] Open
Abstract
BACKGROUND Malignant melanoma (MM) is a highly aggressive skin tumor with a rising incidence and poor prognosis. Although current clinical treatments, including surgery, targeted therapy, immunotherapy, and radiotherapy, have shown some efficacy, therapeutic options remain limited for elderly patients and those with metastatic disease, highlighting the urgent need for novel therapeutic strategies. In recent years, the unique far-infrared radiation (FIR) properties of graphene have demonstrated potential applications in cancer treatment. However, the mechanisms underlying FIR's effects in MM therapy remain poorly understood. METHODS This study systematically evaluated the inhibitory effects of FIR on MM through in vitro cell experiments, animal models, and molecular mechanism analysis. First, the B16F10 melanoma cell line was used as the experimental model. The effects of FIR on cell proliferation, apoptosis, and the cell cycle were assessed using CCK-8 assays and flow cytometry, while RNA sequencing was conducted to analyze the associated signaling pathways. Second, specific caspase inhibitors were employed to further validate the mechanisms of FIR-induced apoptosis. Finally, a syngeneic tumor transplantation model in C57BL/6J mice was established to comfirm the anti-tumor efficacy of FIR in vivo, thereby comprehensively elucidating its anti-cancer mechanisms. RESULTS The results demonstrated that FIR significantly inhibits MM. In vitro experiments revealed that FIR treatment markedly suppressed B16F10 cell proliferation, induced apoptosis, caused G0/G1 phase cell cycle arrest, and downregulated the expression of hypoxia-related proteins such as HIF-1α. In animal studies, FIR significantly inhibited tumor growth. RNA sequencing revealed that FIR exerts its anti-cancer effects through multiple signaling pathways. Notably, the use of caspase inhibitors Z-DEVD-FMK and Z-LEHD-FMK, which specifically inhibit caspase-3 and caspase-9, respectively, can rescue cells from apoptosis induced by FIR treatment. CONCLUSION This study systematically elucidated that FIR exerts anti-tumor effects through multiple mechanisms, including inducing MM cell apoptosis, exacerbating hypoxic stress, and causing cell cycle arrest. The findings provide new insights and approaches for MM treatment and establish a theoretical foundation for the clinical application of FIR in cancer therapy.
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Affiliation(s)
- Wumei Zhao
- Department of Dermatology, School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, 361101, China
| | - Ziwen Chen
- New Cornerstone Science Laboratory, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361101, China
| | - Wenxing Fu
- New Cornerstone Science Laboratory, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361101, China
| | - Chenyan Ye
- Department of Dermatology, School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, 361101, China
| | - Haijing Fu
- Department of Dermatology, School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, 361101, China
| | - Tianyi Xu
- Department of Dermatology, School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, 361101, China
| | - Binghui Wu
- New Cornerstone Science Laboratory, State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and National & Local Joint Engineering Research Center of Preparation Technology of Nanomaterials, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China.
- Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen, 361101, China.
| | - Lina Chen
- Department of cardiology, Shaoxing Central Hospital, Shaoxing, 312030, China.
| | - Shi-Jun Shan
- Department of Dermatology, School of Medicine, Xiang'an Hospital of Xiamen University, Xiamen University, Xiamen, 361101, China.
- Jinhua Fifth Hospital, College of Mathematical Medicine, Zhejiang Normal University, Jinhua, 321004, China.
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Chou MY, Patil AT, Huo D, Lei Q, Kao-Kniffin J, Koch P. Fungicide use intensity influences the soil microbiome and links to fungal disease suppressiveness in amenity turfgrass. Appl Environ Microbiol 2025; 91:e0177124. [PMID: 39982054 PMCID: PMC11921360 DOI: 10.1128/aem.01771-24] [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: 09/05/2024] [Accepted: 01/27/2025] [Indexed: 02/22/2025] Open
Abstract
Disease-suppressive soils have been documented in many economically important crops, but not in turfgrass, one of the most intensively managed plant systems in the United States. Dollar spot, caused by the fungus Clarireedia jacksonii, is the most economically important disease of managed turfgrass and has historically been controlled through the intensive use of fungicides. However, previous anecdotal observations of lower dollar spot severity on golf courses with less intensive fungicide histories suggest that intensive fungicide usage may suppress microbial antagonism of pathogen activity. This study explored the suppressive activity of transplanted microbiomes against dollar spot from seven locations in the Midwestern U.S. and seven locations in the Northeastern U.S. with varying fungicide use histories. Creeping bentgrass was established in pots containing homogenized sterile potting mix and field soil and inoculated with C. jacksonii upon maturity. Bacterial and fungal communities of root-associated soil and phyllosphere were profiled with short-amplicon sequencing to investigate the microbial community associated with disease suppression. The results showed that plants grown in the transplanted soil microbiome collected from sites with lower fungicide intensities exhibited reduced disease severity. Plant growth-promoting and pathogen-antagonistic microbes may be responsible for disease suppression, but further validation is required. Additional least squares regression analysis of the fungicides used at each location suggested that contact fungicides such as chlorothalonil and fluazinam had a greater influence on the microbiome disease suppressiveness than penetrant fungicides. Potential organisms antagonistic to Clarireedia were identified in the subsequent amplicon sequencing analysis, but further characterization and validation are required. IMPORTANCE Given the current reliance on fungicides for plant disease control, this research provides new insights into the potential non-target effects of repeated fungicide usage on disease-suppressive soils. It also indicates that intensive fungicide usage can decrease the activity of beneficial soil microbes and lead to a more disease conducive microbial environment in turfgrass. The results from this study can be used to identify more sustainable disease management strategies for a variety of economically important and intensively managed pathosystems. Understanding the factors that facilitate disease-suppressive soils will contribute to more sustainable plant protection practices.
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Affiliation(s)
- Ming-Yi Chou
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Plant Biology, Rutgers University, New Brunswick, New Jersey, USA
| | | | - Daowen Huo
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Qiwei Lei
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jenny Kao-Kniffin
- Horticulture Section, School of Integrative Plant Science, Cornell University, Ithaca, New York, USA
| | - Paul Koch
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Poznanski P, Shalmani A, Poznanski P, Orczyk W. The Synergy of Chitosan and Azoxystrobin Against Fusarium graminearum Is Modulated by Selected ABC Transporters. Int J Mol Sci 2024; 26:262. [PMID: 39796115 PMCID: PMC11719997 DOI: 10.3390/ijms26010262] [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: 11/29/2024] [Revised: 12/23/2024] [Accepted: 12/28/2024] [Indexed: 01/13/2025] Open
Abstract
The development of innovative and effective strategies to combat fungal pathogens is critical to sustainable crop protection. Fungicides have been used for over two centuries, with traditional copper- and sulfur-based formulations still in use due to their broad-spectrum, multisite mode of action, which minimizes the risk of pathogen resistance. In contrast, modern systemic fungicides, though potent, often target a single site of action, leading to the accelerated emergence of resistant fungal strains. This study explores synergistic interactions between chitosan (CS) and selected fungicides, focusing on their antifungal activity against Fusarium graminearum. Among the fungicides tested, azoxystrobin (Amistar) exhibited the highest 44.88 synergy score when combined with CS (30 kDa, degree of deacetylation ≥ 90), resulting in significantly improved antifungal efficacy. Furthermore, the combination of CS and Amistar with double-stranded RNA (dsRNA) targeting selected ABC transporter genes further amplified antifungal activity by silencing genes critical for fungal tolerance to treatment. This dual synergy highlights the potential of RNA interference (RNAi) as both a functional tool to investigate fungal physiology and an effective antifungal strategy. These findings reveal a promising and environmentally friendly approach to mitigate resistance while improving fungal control. Furthermore, the remarkable synergy between azoxystrobin and CS presents a novel mechanism with significant potential for sustainable agricultural applications, which warrants further investigation to elucidate its molecular basis.
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Affiliation(s)
- Pawel Poznanski
- Plant Breeding and Acclimatization Institute—National Research Institute, Radzikow, 05-870 Blonie, Poland
| | - Abdullah Shalmani
- Plant Breeding and Acclimatization Institute—National Research Institute, Radzikow, 05-870 Blonie, Poland
| | - Pascal Poznanski
- Ludwik Rydygier Collegium Medicum in Bydgoszcz, Nicolaus Copernicus University in Torun, 85-094 Bydgoszcz, Poland
| | - Waclaw Orczyk
- Plant Breeding and Acclimatization Institute—National Research Institute, Radzikow, 05-870 Blonie, Poland
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Shi X, Min S, Jung G. Field Evaluation of Fluazinam Fungicide in Dollar Spot Populations Confirmed In Vitro Insensitivity. PLANT DISEASE 2024; 108:3329-3335. [PMID: 38985511 DOI: 10.1094/pdis-12-23-2639-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2024]
Abstract
Fluazinam, a fungicide widely used in agriculture and turf management, was traditionally thought to pose a low risk of resistance. However, our in vitro sensitivity test conducted in 2021 revealed reduced sensitivity to fluazinam in dollar spot, highlighting the need for more vigilant field monitoring. In 2022 and 2023, we evaluated the field responses of four Clarireedia jacksonii isolates with varying in vitro sensitivity to fluazinam. Fluazinam was used at both a full labeled rate (0.5 oz/1,000 ft2) and a half-rate (0.25 oz/1,000 ft2) to evaluate the effectiveness in isolate-inoculated plots in the field. In 2022, both natural and sensitive isolates showed significantly better control compared to insensitive isolates under both half- and full-rate treatments. However, in 2023, half-rate fluazinam demonstrated limited control under high disease pressure, providing relative disease control of dollar spot less than 45% across all treatments. In contrast, full-rate fluazinam maintained significantly better control of natural and sensitive isolates compared with insensitive isolates. Our results, showing that in vitro insensitivity leads to field insensitivity under inoculated conditions, suggest the development of fluazinam insensitivity in the C. jacksonii population. This highlights the need for judicious use of fluazinam and the establishment of continuous resistance monitoring. Furthermore, the loss of control observed when fluazinam was applied at half-rates under high disease pressure highlights the importance of careful fungicide use.
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Affiliation(s)
- Xiaojing Shi
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - Soonhong Min
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
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Huo D, Westrick NM, Nelson A, Kabbage M, Koch P. The Role of Oxalic Acid in Clarireedia jacksonii Virulence and Development on Creeping Bentgrass. PHYTOPATHOLOGY 2024; 114:2394-2400. [PMID: 39145740 DOI: 10.1094/phyto-03-24-0094-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2024]
Abstract
Dollar spot is a destructive foliar disease of amenity turfgrass caused by Clarireedia spp. fungi, mainly C. jacksonii, on the Northern United States region's cool-season grass. Oxalic acid (OA) is an important pathogenicity factor in related fungal plant pathogens such as Sclerotinia sclerotiorum; however, the role of OA in the pathogenic development of C. jacksonii remains unclear due to its recalcitrance to genetic manipulation. To overcome these challenges, a CRISPR/Cas9-mediated homologous recombination approach was developed. Using this novel approach, the oxaloacetate acetylhydrolase (oah) gene that is required for the biosynthesis of OA was deleted from a C. jacksonii wild-type (WT) strain. Two independent knockout mutants, ΔCjoah-1 and ΔCjoah-2, were generated and inoculated on potted creeping bentgrass along with a WT isolate and a genome sequenced isolate LWC-10. After 12 days, bentgrass inoculated with the mutants ΔCjoah-1 and ΔCjoah-2 exhibited 59.41% lower dollar spot severity compared with the WT and LWC-10 isolates. OA production and environmental acidification were significantly reduced in both mutants when compared with the WT and LWC-10. Surprisingly, stromal formation was also severely undermined in the mutants in vitro, suggesting a critical developmental role of OA independent of plant infection. These results demonstrate that OA plays a significant role in C. jacksonii virulence and provide novel directions for future management of dollar spot. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Daowen Huo
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, U.S.A
| | - Nathaniel M Westrick
- Valley Laboratory, Connecticut Agricultural Experiment Station, Windsor, CT, U.S.A
| | - Ashley Nelson
- Department of Plant Pathology, North Dakota State University, Fargo, ND, U.S.A
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, U.S.A
| | - Paul Koch
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, U.S.A
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Zhang H, Jin P, Kong Y, Jia C, Qiao P, Dong Y, Zhou Y, Hu J, Yang Z, Jung G. Mutations across Diverse Domains of CjXDR1 Lead to Multidrug Resistance in Clarireedia jacksonii. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 39352294 DOI: 10.1021/acs.jafc.4c05106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2024]
Abstract
Recently, Clarireedia jacksonii has emerged as a significant pathogen threatening turfgrass, and its escalating resistance to multiple drugs often undermines field interventions. This study highlighted the critical role of the fungus-specific transcription factor CjXDR1 (formerly ShXDR1) in regulating multidrug resistance (MDR) in C. jacksonii. This was demonstrated through experiments involving CjXDR1-knockout and CjXDR1-complemented strains. Our sequence analysis revealed five mutations in CjXDR1: G445D, K453E, S607F, D676H, and V690A. All five gain-of-function (GOF) mutations were confirmed to directly contribute to MDR against three different classes of fungicides (propiconazole: demethylation inhibitor, boscalid: succinate dehydrogenase inhibitor, and iprodione: dicarboximide) using the genetic transformation system and in vitro fungicide-sensitivity assay. Comparative transcriptome analysis revealed that CjXDR1 and its GOF mutations led to the overexpression of downstream genes encoding a Phase I metabolizing enzyme (CYP68) and two Phase III transporters (CjPDR1 and CjAtrD) previously reported. Knockout mutants of CYP68, CjPDR1, CjAtrD, and double-knockout mutants of CjPDR1 and CjAtrD exhibited increased sensitivity to all three fungicides tested. Among these, the CYP68-knockout mutants displayed the highest sensitivity to propiconazole, while the CjPDR1 knockout mutant exhibited significantly increased sensitivity to all three fungicides. Double-knockout mutants of CjPDR1 and CjAtrD displayed greater sensitivity than the single knockouts. In conclusion, multiple GOF mutants in CjXDR1 contribute to MDR by upregulating the expression of CjPDR1, CjAtrD, and CYP68. This study enhances our understanding of the molecular mechanisms underlying MDR in plant pathogenic fungi, providing valuable insights into GOF mutation structures and advancing the development of antifungal drugs.
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Affiliation(s)
- Huangwei Zhang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States
| | - Peiyuan Jin
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Yixuan Kong
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Chenchen Jia
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Panpan Qiao
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Yinglu Dong
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuxin Zhou
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing 210095, China
| | - Jian Hu
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Zhimin Yang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, China
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts 01003, United States
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Hu J, Zhang H, Kong Y, Lamour K, Jung G, Yang Z. Varied sensitivity to boscalid among different Clarireedia species causing dollar spot in turfgrass. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 204:106029. [PMID: 39277357 DOI: 10.1016/j.pestbp.2024.106029] [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: 05/22/2024] [Revised: 07/11/2024] [Accepted: 07/13/2024] [Indexed: 09/17/2024]
Abstract
Dollar spot, a highly destructive turfgrasses disease worldwide, is caused by multiple species within the genus Clarireedia. Previous research indicated varying sensitivity to boscalid among Clarireedia populations not historically exposed to succinate dehydrogenase inhibitors (SDHIs). This study confirms that the differential sensitivity pattern is inherent among different Clarireedia spp., utilizing a combination of phylogenetic analyses, in vitro cross-resistance assays, and genetic transformation of target genes with different mutations. Furthermore, greenhouse inoculation experiments revealed that the differential boscalid sensitivity did not lead to pathogenicity issues or fitness penalties, thereby not resulting in control failure by boscalid. This research underscores the importance of continuous monitoring of fungicide sensitivity trends and highlights the complexity of chemical control of dollar spot due to the inherent variability in fungicide sensitivity among different Clarireedia spp.
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Affiliation(s)
- Jian Hu
- College of Agro-grassland Science, Nanjing Agircultural University, Nanjing, Jiangsu 210095, PR China
| | - Huangwei Zhang
- College of Agro-grassland Science, Nanjing Agircultural University, Nanjing, Jiangsu 210095, PR China
| | - Yixuan Kong
- College of Agro-grassland Science, Nanjing Agircultural University, Nanjing, Jiangsu 210095, PR China
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, United States
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, United States
| | - Zhimin Yang
- College of Agro-grassland Science, Nanjing Agircultural University, Nanjing, Jiangsu 210095, PR China.
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Liu J, Wu J, Jin P, Hu J, Lamour K, Yang Z. Activity of the Succinate Dehydrogenase Inhibitor Fungicide Benzovindiflupyr Against Clarireedia spp. PLANT DISEASE 2023; 107:3924-3932. [PMID: 37340553 DOI: 10.1094/pdis-02-23-0201-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
Dollar spot (DS), caused by Clarireedia spp. (formerly Sclerotinia homoeocarpa), is one of the most important diseases of turfgrasses worldwide. Benzovindiflupyr, a pyrazole carboxamide fungicide belonging to succinate dehydrogenase inhibitors, was recently registered for DS control. In this study, baseline sensitivity, toxicity, and control efficacy of benzovindiflupyr against Clarireedia spp. were evaluated. The frequency of sensitivities had a unimodal distribution (Kolmogorov-Smirnov, P > 0.10). The mean EC50 value was 1.109 ± 0.555 μg/ml, with individual values ranging from 0.160 to 2.548 μg/ml. Benzovindiflupyr increased the number of hyphal offshoots and cell membrane permeability and inhibited oxalic acid production. Positive cross-resistance was observed between benzovindiflupyr and boscalid, but not between benzovindiflupyr and thiophanate-methyl, propiconazole, or iprodione. Benzovindiflupyr showed high protective and curative control efficacies in vivo and in field applications. Both protective and curative control efficacies of benzovindiflupyr were significantly better than propiconazole, and equivalent to boscalid, over 2 years of field research. The results have important implications for managing DS and fungicide resistance problems in Clarireedia spp.
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Affiliation(s)
- Jun Liu
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Jiaxuan Wu
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Peiyuan Jin
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Jian Hu
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, P.R. China
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, U.S.A
| | - Zhimin Yang
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing 210095, P.R. China
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Dorigan AF, Moreira SI, da Silva Costa Guimarães S, Cruz-Magalhães V, Alves E. Target and non-target site mechanisms of fungicide resistance and their implications for the management of crop pathogens. PEST MANAGEMENT SCIENCE 2023; 79:4731-4753. [PMID: 37592727 DOI: 10.1002/ps.7726] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/14/2023] [Accepted: 08/18/2023] [Indexed: 08/19/2023]
Abstract
Fungicides are indispensable for high-quality crops, but the rapid emergence and evolution of fungicide resistance have become the most important issues in modern agriculture. Hence, the sustainability and profitability of agricultural production have been challenged due to the limited number of fungicide chemical classes. Resistance to site-specific fungicides has principally been linked to target and non-target site mechanisms. These mechanisms change the structure or expression level, affecting fungicide efficacy and resulting in different and varying resistance levels. This review provides background information about fungicide resistance mechanisms and their implications for developing anti-resistance strategies in plant pathogens. Here, our purpose was to review changes at the target and non-target sites of quinone outside inhibitor (QoI) fungicides, methyl-benzimidazole carbamate (MBC) fungicides, demethylation inhibitor (DMI) fungicides, and succinate dehydrogenase inhibitor (SDHI) fungicides and to evaluate if they may also be associated with a fitness cost on crop pathogen populations. The current knowledge suggests that understanding fungicide resistance mechanisms can facilitate resistance monitoring and assist in developing anti-resistance strategies and new fungicide molecules to help solve this issue. © 2023 Society of Chemical Industry.
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Affiliation(s)
| | | | | | | | - Eduardo Alves
- Department of Plant Pathology, Federal University of Lavras, Lavras, Brazil
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Huangwei Z, Peiyuan J, Yixuan K, Zhimin Y, Yuxin Z, Geunhwa J, Jian H. Genome-wide transcriptional analyses of Clarireedia jacksonii isolates associated with multi-drug resistance. Front Microbiol 2023; 14:1266045. [PMID: 37840738 PMCID: PMC10570728 DOI: 10.3389/fmicb.2023.1266045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 08/30/2023] [Indexed: 10/17/2023] Open
Abstract
Emerging multidrug resistance (MDR) in Clarireedia spp. is a huge challenge to the management of dollar spot (DS) disease on turfgrass. Insight into the molecular basis of resistance mechanisms may help identify key molecular targets for developing novel effective chemicals. Previously, a MDR isolate (LT586) of C. jacksonii with significantly reduced sensitivities to propiconazole, boscalid, and iprodione, and a fungicide-sensitive isolate (LT15) of the same species were isolated from creeping bentgrass (Agrostis stolonifera L.). The present study aimed to further explore the molecular mechanisms of resistance by using genome-wide transcriptional analyses of the two isolates. A total of 619 and 475 differentially expressed genes (DEGs) were significantly down and upregulated in the MDR isolate LT586, compared with the sensitive isolate LT15 without fungicide treatment. Three hundreds and six and 153 DEGs showed significantly lower and higher expression in the MDR isolate LT586 than those in the sensitive isolate LT15, which were commonly induced by the three fungicides. Most of the 153 upregulated DEGs were xenobiotic detoxification-related genes and genes with transcriptional functions. Fifty and 17 upregulated DEGs were also commonly observed in HRI11 (a MDR isolate of the C. jacksonii) compared with the HRS10 (a fungicide-sensitive isolate of same species) from a previous study without and with the treatment of propiconazole, respectively. The reliability of RNA-seq data was further verified by qRT-PCR method using a few select potentially MDR-related genes. Results of this study indicated that there were multiple uncharacterized genes, possibly responsible for MDR phenotypes in Clarireedia spp., which may have important implications in understanding the molecular mechanisms underlying MDR resistance.
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Affiliation(s)
- Zhang Huangwei
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Jin Peiyuan
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Kong Yixuan
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Yang Zhimin
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
| | - Zhou Yuxin
- Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China
| | - Jung Geunhwa
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA, United States
| | - Hu Jian
- College of Agro-Grassland Science, Nanjing Agricultural University, Nanjing, China
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12
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Cheng X, Zhang J, Liang Z, Wu Z, Liu P, Hao J, Liu X. Multidrug resistance of Rhizoctonia solani determined by enhanced efflux for fungicides. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 195:105525. [PMID: 37666584 DOI: 10.1016/j.pestbp.2023.105525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/26/2023] [Accepted: 07/10/2023] [Indexed: 09/06/2023]
Abstract
Plant pathogens can develop multidrug resistance (MDR) through metabolomic and efflux activities. Although MDR has been observed in the field, its mechanisms are yet to be further studied. MDR in Rhizoctonia solani induced by the uncoupler SYP-14288, which involved efflux transporters including ATP binding cassette (ABC) and major facilitator superfamily (MFS) have been reported in our previous study. To confirm this, corresponding genes of the wild-type R. solani X19 and its derived MDR mutant X19-7 were compared through transcriptomics, RNA-Seq data validation, and heterologous expression. Genes encoding six ABC transporters and seven MFS transporters were identified to be associated with MDR and mostly showed a constitutively higher expression in X19-7 than in X19 regardless of SYP-14288 treatment. Eight ABC transporter-encoding genes and eight MFS transporter-encoding genes were further characterized by transferring into Saccharomyces cerevisiae. The sensitivity of transformants containing either ABC transporter-encoding gene AG1IA_06082 and MFS transporter-encoding gene AG1IA_08645 was significantly decreased in responses to fungicides having various modes of action including SYP-14288, fluazinam, chlorothalonil, and difenoconazole, indicating that these two genes were related to MDR. The roles of two genes were further confirmed by successfully detecting their protein products and high accumulation of SYP-14288 in yeast transformants. Thus, ABC and MFS transporters contributed to the development of MDR in R. solani. The result helps to understand the cause and mechanisms that influence the efficient use of fungicide.
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Affiliation(s)
- Xingkai Cheng
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Junting Zhang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Zhengya Liang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Zhaochen Wu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Pengfei Liu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China.
| | - Jianjun Hao
- School of Food and Agriculture, University of Maine, Orono, ME 04469, USA
| | - Xili Liu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
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Ghimire B, Aktaruzzaman M, Chowdhury SR, Spratling WT, Vermeer CB, Buck JW, Martinez-Espinoza AD, Bahri BA. Sensitivity of Clarireedia spp. to benzimidazoles and dimethyl inhibitors fungicides and efficacy of biofungicides on dollar spot of warm season turfgrass. FRONTIERS IN PLANT SCIENCE 2023; 14:1155670. [PMID: 37360709 PMCID: PMC10288879 DOI: 10.3389/fpls.2023.1155670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/24/2023] [Indexed: 06/28/2023]
Abstract
Dollar spot caused by Clarireedia spp. (formerly Sclerotinia homoeocarpa) is an economically destructive fungal disease of turfgrass that can significantly compromise turf quality, playability, and aesthetic value. Fungicides are frequently used to manage the disease but are costly and potentially unfavorable to the environment. Repeated use of some active ingredients has resulted in reduced efficacy on C. jacksonii causing dollar spot in cool-season turfgrasses in the US. Experiments were conducted to study fungicide sensitivity of Clarireedia spp. as well as to develop alternatives to fungicides against dollar spot on warm-season turfgrass in Georgia. First, 79 isolates of Clarireedia spp. collected across the state were tested on fungicide-amended agar plates for their sensitivity to thiophanate-methyl (benzimidazole) and propiconazole (dimethyl inhibitor). Seventy-seven isolates (97.5%) were sensitive (0.001 to 0.654 μg/mL) and two isolates (2.5%) were found resistant (>1000 μg/mL) to thiophanate-methyl. However, in the case of propiconazole, 27 isolates (34.2%) were sensitive (0.005 to 0.098 μg/mL) while 52 isolates (65.8%) were resistant (0.101 to 3.820 μg/mL). Next, the efficacy of three bio- and six synthetic fungicides and ten different combinations were tested in vitro against C. monteithiana. Seven bio- and synthetic fungicide spray programs comprising Bacillus subtilis QST713 and propiconazole were further tested, either alone or in a tank mix in a reduced rate, on dollar spot infected bermudagrass 'TifTuf' in growth chamber and field environments. These fungicides were selected as they were found to significantly reduce pathogen growth up to 100% on in vitro assays. The most effective spray program in growth chamber assays was 100% B. subtilis QST713 in rotation with 75% B. subtilis QST713 + 25% propiconazole tank mix applied every 14 days. However, the stand-alone application of the biofungicide B. subtilis QST713 every seven days was an effective alternative and equally efficacious as propiconazole, suppressing dollar spot severity and AUDPC up to 75%, while resulting in acceptable turf quality (>7.0) in field experiments. Our study suggests that increased resistance of Clarireedia spp. to benzimidazoles and dimethyl inhibitors warrants continuous surveillance and that biofungicides hold promise to complement synthetic fungicides in an efficacious and environmentally friendly disease management program.
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Affiliation(s)
- Bikash Ghimire
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States
| | - Md. Aktaruzzaman
- Department of Plant Pathology, University of Georgia, Tifton, GA, United States
| | - Shukti R. Chowdhury
- Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Willis T. Spratling
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
| | - C. Brian Vermeer
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
| | - James W. Buck
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
| | | | - Bochra A. Bahri
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States
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Zhang H, Dong Y, Jin P, Hu J, Lamour K, Yang Z. Genome Resources for Four Clarireedia Species Causing Dollar Spot on Diverse Turfgrasses. PLANT DISEASE 2023; 107:929-934. [PMID: 36265142 DOI: 10.1094/pdis-08-22-1921-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Dollar spot (DS) is a destructive fungal disease impacting almost all warm- and cool-season turfgrasses worldwide. Multiple fungal species in the genus Clarireedia are causal agents of DS. Here, we present whole-genome assemblies of nine fungal isolates in the genus Clarireedia, including four species (C. paspali, C. hainanense, C. jacksonii, and C. monteithiana) causing DS on seashore paspalum (Paspalum vaginatum Sw.), creeping bentgrass (Agrostis stolonifera L.), and Kentucky bluegrass (Poa pratensis L.) in China. This work provides valuable baseline genomic data to support further research and management of DS pathogens on turfgrasses.
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Affiliation(s)
- Huangwei Zhang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Yinglu Dong
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Peiyuan Jin
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Jian Hu
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095, P.R. China
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville, TN 37996, U.S.A
| | - Zhimin Yang
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing, 210095, P.R. 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: 7] [Impact Index Per Article: 2.3] [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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16
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Wang ZQ, Meng FZ, Yin LF, Yin WX, Lv L, Yang XL, Chang XQ, Zhang S, Luo CX. Transcriptomic Analysis of Resistant and Wild-Type Isolates Revealed Fludioxonil as a Candidate for Controlling the Emerging Isoprothiolane Resistant Populations of Magnaporthe oryzae. Front Microbiol 2022; 13:874497. [PMID: 35464942 PMCID: PMC9024399 DOI: 10.3389/fmicb.2022.874497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/23/2022] [Indexed: 11/22/2022] Open
Abstract
The point mutation R343W in MoIRR, a putative Zn2Cys6 transcription factor, introduces isoprothiolane (IPT) resistance in Magnaporthe oryzae. However, the function of MoIRR has not been characterized. In this study, the function of MoIRR was investigated by subcellular localization observation, transcriptional autoactivation test, and transcriptomic analysis. As expected, GFP-tagged MoIRR was translocated in the nucleus, and its C-terminal could autonomously activate the expression of reporter genes HIS3 and α-galactosidase in absence of any prey proteins in Y2HGold, suggesting that MoIRR was a typical transcription factor. Transcriptomic analysis was then performed for resistant mutant 1a_mut (R343W), knockout transformant ΔMoIRR-1, and their parental wild-type isolate H08-1a. Upregulated genes in both 1a_mut and ΔMoIRR-1 were involved in fungicide resistance-related KEGG pathways, including the glycerophospholipid metabolism and Hog1 MAPK pathways. All MoIRR deficiency-related IPT-resistant strains exhibited increased susceptibility to fludioxonil (FLU) that was due to the upregulation of Hog1 MAPK pathway genes. The results indicated a correlation between FLU susceptibility and MoIRR deficiency-related IPT resistance in M. oryzae. Thus, using a mixture of IPT and FLU could be a strategy to manage the IPT-resistant populations of M. oryzae in rice fields.
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Affiliation(s)
- Zuo-Qian Wang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of Agriculture, Wuhan, China
| | - Fan-Zhu Meng
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Liang-Fen Yin
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Wei-Xiao Yin
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Liang Lv
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of Agriculture, Wuhan, China
| | - Xiao-Lin Yang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of Agriculture, Wuhan, China
| | - Xiang-Qian Chang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of Agriculture, Wuhan, China
| | - Shu Zhang
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural Sciences, Wuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of Agriculture, Wuhan, China
- *Correspondence: Shu Zhang,
| | - Chao-Xi Luo
- Department of Plant Pathology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
- The Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, China
- Chao-Xi Luo,
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17
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Zhao C, Li Y, Liang Z, Gao L, Han C, Wu X. Molecular Mechanisms Associated with the Resistance of Rhizoctonia solani AG-4 Isolates to the Succinate Dehydrogenase Inhibitor Thifluzamide. PHYTOPATHOLOGY 2022; 112:567-578. [PMID: 34615378 DOI: 10.1094/phyto-06-21-0266-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Thifluzamide, a succinate dehydrogenase (SDH) inhibitor, possesses high activity against Rhizoctonia. In this study, 144 Rhizoctonia solani AG-4 (4HGI, 4HGII, and 4HGIII) isolates, the predominate pathogen associated with sugar beet seedling damping-off, were demonstrated to be sensitive to thifluzamide with a calculated mean median effective concentration of 0.0682 ± 0.0025 μg/ml. Thifluzamide-resistant isolates were generated using fungicide-amended media, resulting in four AG-4HGI isolates and eight AG-4HGII isolates with stable resistance and almost no loss in fitness. Evaluation of cross-resistance of the 12 thifluzamide-resistant isolates and their corresponding parental-sensitive isolates revealed a moderately positive correlation between thifluzamide resistance and the level of resistance to eight other fungicides from three groups, the exception being fludioxonil. An active efflux of fungicide through ATP-binding cassette and major facilitator superfamily transporters was found to be correlated to the resistance of R. solani AG-4HGII isolates to thifluzamide based on RNA-sequencing and quantitative reverse transcription-PCR analyses. Sequence analysis of sdhA, sdhB, sdhC, and sdhD revealed replacement of isoleucine by phenylalanine at position 61 in SDHC in 9 of the 12 generated thifluzamide-resistant isolates. No other mutations were found in any of the other genes. Collectively, the data indicate that the active efflux of fungicide and a point mutation in sdhC may contribute to the resistance of R. solani AG-4HGI and AG-4HGII isolates to thifluzamide in vitro. This is the first characterization of the potential molecular mechanism associated with the resistance of R. solani AG-4 isolates to thifluzamide and provides practical guidance for the use of this fungicide.
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Affiliation(s)
- Can Zhao
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
- College of Horticulture, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
| | - Yuting Li
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
| | - Zhijian Liang
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
| | - Lihong Gao
- College of Horticulture, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
| | - Chenggui Han
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
| | - Xuehong Wu
- College of Plant Protection, China Agricultural University, Haidian District, Beijing 100193, People's Republic of China
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18
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Zhao Y, Zhang L, Ju C, Zhang X, Huang J. Quantitative multiplexed proteomics analysis reveals reshaping of the lysine 2-hydroxyisobutyrylome in Fusarium graminearum by tebuconazole. BMC Genomics 2022; 23:145. [PMID: 35180840 PMCID: PMC8855566 DOI: 10.1186/s12864-022-08372-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 02/04/2022] [Indexed: 11/30/2022] Open
Abstract
Backgrounds Lysine 2-hydroxyisobutyrylation (Khib) is a newly discovered posttranslational modification (PTM) and has been identified in several prokaryotic and eukaryotic organisms. Fusarium graminearum, a major pathogen of Fusarium head blight (FHB) in cereal crops, can cause considerable yield loss and produce various mycotoxins that threaten human health. The application of chemical fungicides such as tebuconazole (TEC) remains the major method to control this pathogen. However, the distribution of Khib in F. graminearum and whether Khib is remodified in response to fungicide stress remain unknown. Results Here, we carried out a proteome-wide analysis of Khib in F. graminearum, identifying the reshaping of the lysine 2-hydroxyisobutyrylome by tebuconazole, using the most recently developed high-resolution LC–MS/MS technique in combination with high-specific affinity enrichment. Specifically, 3501 Khib sites on 1049 proteins were identified, and 1083 Khib sites on 556 modified proteins normalized to the total protein content were changed significantly after TEC treatment. Bioinformatics analysis showed that Khib proteins are involved in a wide range of biological processes and may be involved in virulence and deoxynivalenol (DON) production, as well as sterol biosynthesis, in F. graminearum. Conclusions Here, we provided a wealth of resources for further study of the roles of Khib in the fungicide resistance of F. graminearum. The results enhanced our understanding of this PTM in filamentous ascomycete fungi and provided insight into the remodification of Khib sites during azole fungicide challenge in F. graminearum. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08372-4.
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Affiliation(s)
- Yanxiang Zhao
- College of Plant Health and Medicine and Key Lab of Integrated Crop Disease and Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, China
| | - Limin Zhang
- College of Plant Health and Medicine and Key Lab of Integrated Crop Disease and Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, China
| | - Chao Ju
- College of Plant Health and Medicine and Key Lab of Integrated Crop Disease and Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, China
| | - Xiaoyan Zhang
- College of Agriculture, Ludong University, Yantai, 264025, Shandong Province, China
| | - Jinguang Huang
- College of Plant Health and Medicine and Key Lab of Integrated Crop Disease and Pest Management of Shandong Province, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, China.
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19
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Kailasam S, Sundaramanickam A, Tamilvanan R, Kanth SV. Macrophytic waste optimization by synthesis of silver nanoparticles and exploring their agro-fungicidal activity. INORG NANO-MET CHEM 2022. [DOI: 10.1080/24701556.2022.2034013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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20
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Sang H, Chang HX, Choi S, Son D, Lee G, Chilvers MI. Genome-wide transcriptional response of the causal soybean sudden death syndrome pathogen Fusarium virguliforme to a succinate dehydrogenase inhibitor fluopyram. PEST MANAGEMENT SCIENCE 2022; 78:530-540. [PMID: 34561937 DOI: 10.1002/ps.6657] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Succinate dehydrogenase inhibitors (SDHIs) have been widely used to manage plant diseases caused by phytopathogenic fungi. Although attention to and use of SDHI fungicides has recently increased, molecular responses of fungal pathogens to SDHIs have often not been investigated. A SDHI fungicide, fluopyram, has been used as a soybean seed treatment and has displayed effective control of Fusarium virguliforme, one of the causal agents of soybean sudden death syndrome. To examine genome-wide gene expression of F. virguliforme to fluopyram, RNA-seq analysis was conducted on two field strains of F. virguliforme with differing SDHI fungicide sensitivity in the absence and presence of fluopyram. RESULTS The analysis indicated that several xenobiotic detoxification-related genes, such as those of deoxygenase, transferases and transporters, were highly induced by fluopyram. Among the genes, four ATP-binding cassette (ABC) transporters were characterized by the yeast expression system. The results revealed that expression of three ABCG transporters was associated with reduced sensitivity to multiple fungicides including fluopyram. In addition, heterologous expression of a major facilitator superfamily (MFS) transporter that was highly expressed in the fluopyram-insensitive F. virguliforme strain in the yeast system conferred decreased sensitivity to fluopyram. CONCLUSION This study demonstrated that xenobiotic detoxification-related genes were highly upregulated in response to fluopyram, and expression of ABC or MFS transporter genes was associated with reduced sensitivity to the SDHI fungicide. This is the first transcriptomic analysis of the fungal species response to fluopyram and the finding will help elucidate the molecular mechanisms of SDHI resistance. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Hyunkyu Sang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
- Kumho Life Science Laboratory, Chonnam National University, Gwangju, South Korea
| | - Hao-Xun Chang
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Sungyu Choi
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Doeun Son
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Gahee Lee
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, South Korea
| | - Martin I Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, Michigan, USA
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21
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Resistance to the SDHI Fungicides Boscalid and Fluopyram in Podosphaera xanthii Populations from Commercial Cucurbit Fields in Spain. J Fungi (Basel) 2021; 7:jof7090733. [PMID: 34575771 PMCID: PMC8464660 DOI: 10.3390/jof7090733] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 08/27/2021] [Accepted: 09/06/2021] [Indexed: 01/23/2023] Open
Abstract
Powdery mildew is caused by Podosphaera xanthii, and is one of the most important diseases that attacks Spanish cucurbit crops. Fungicide application is the primary control tool; however, its effectiveness is hampered by the rapid development of resistance to these compounds. In this study, the EC50 values of 26 isolates were determined in response to the succinate dehydrogenase inhibitor (SDHI) fungicides boscalid and fluopyram. From these data, the discriminatory doses were deduced and used for SDHI resistance monitoring during the 2018 and 2019 growing seasons. Of the 298 isolates analysed, 37.9% showed resistance to boscalid and 44% to fluopyram. Although different phenotypes were observed in leaf disc assays, the resistant isolates showed the same phenotype in plant assays. Compared to sensitive isolates, two amino acid changes were found in the SdhC subunit, A86V and G151R, which are associated mostly with resistance patterns to fluopyram and boscalid, respectively. Furthermore, no significant differences were observed in terms of fitness cost between the selected sensitive and resistant isolates analysed here. Lastly, a loop-mediated isothermal amplification (LAMP) assay was developed to detect A86V and G151R mutations using conidia obtained directly from infected material. Our results show that growers could continue to use boscalid and fluopyram, but resistance management practices must be implemented.
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Fouché G, Michel T, Lalève A, Wang NX, Young DH, Meunier B, Debieu D, Fillinger S, Walker AS. Directed evolution predicts cytochrome b G37V target site modification as probable adaptive mechanism towards the QiI fungicide fenpicoxamid in Zymoseptoria tritici. Environ Microbiol 2021; 24:1117-1132. [PMID: 34490974 DOI: 10.1111/1462-2920.15760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/03/2021] [Accepted: 09/04/2021] [Indexed: 02/06/2023]
Abstract
Acquired resistance is a threat to antifungal efficacy in medicine and agriculture. The diversity of possible resistance mechanisms and highly adaptive traits of pathogens make it difficult to predict evolutionary outcomes of treatments. We used directed evolution as an approach to assess the resistance risk to the new fungicide fenpicoxamid in the wheat pathogenic fungus Zymoseptoria tritici. Fenpicoxamid inhibits complex III of the respiratory chain at the ubiquinone reduction site (Qi site) of the mitochondrially encoded cytochrome b, a different site than the widely used strobilurins which inhibit the same complex at the ubiquinol oxidation site (Qo site). We identified the G37V change within the cytochrome b Qi site as the most likely resistance mechanism to be selected in Z. tritici. This change triggered high fenpicoxamid resistance and halved the enzymatic activity of cytochrome b, despite no significant penalty for in vitro growth. We identified negative cross-resistance between isolates harbouring G37V or G143A, a Qo site change previously selected by strobilurins. Double mutants were less resistant to both QiIs and quinone outside inhibitors compared to single mutants. This work is a proof of concept that experimental evolution can be used to predict adaptation to fungicides and provides new perspectives for the management of QiIs.
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Affiliation(s)
- Guillaume Fouché
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, 78850, France.,Corteva Agriscience, 9330 Zionsville Road, Indianapolis, IN, 46268, USA
| | - Thomas Michel
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, 91198, France
| | - Anaïs Lalève
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, 78850, France
| | - Nick X Wang
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, IN, 46268, USA
| | - David H Young
- Corteva Agriscience, 9330 Zionsville Road, Indianapolis, IN, 46268, USA
| | - Brigitte Meunier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, 91198, France
| | - Danièle Debieu
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, 78850, France
| | - Sabine Fillinger
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, 78850, France
| | - Anne-Sophie Walker
- Université Paris-Saclay, INRAE, AgroParisTech, UMR BIOGER, Thiverval-Grignon, 78850, France
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Lee J, Elliott MR, Yamada T, Jung G. Field Assessment of Six Point-Mutations in SDH Subunit Genes Conferring Varying Resistance Levels to SDHIs in Clarireedia spp. PLANT DISEASE 2021; 105:1685-1691. [PMID: 33944573 DOI: 10.1094/pdis-06-20-1344-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Dollar spot, caused by Clarireedia spp. (formerly Sclerotinia homoeocarpa F.T. Bennett), is the most economically important turfgrass disease causing considerable damage on golf courses. While cultural practices are available for reducing dollar spot infection, chemical fungicide use is often necessary for maintaining optimal turf quality. Since the release of boscalid in 2003, the succinate dehydrogenase inhibitor (SDHI) class has become an invaluable tool for managing dollar spot. However, resistance to this class has recently been reported in Clarireedia spp. and many other plant pathogenic fungi. After SDHI field failure on four golf courses and one university research plot, a total of six unique SDH mutations conferring differential in vitro sensitivities to SDHIs have been identified in Clarireedia spp. In 2018 and 2019, turf research plots were inoculated with sensitive, non-mutated isolates of Clarireedia spp., as well as resistant isolates harboring each unique identified mutation. Fungicide efficacy trials were conducted on inoculated plots to assess differential sensitivity to five SDHI active ingredients (boscalid, fluxapyroxad, isofetamid, fluopyram, and pydiflumetofen) across mutations under field conditions. Results indicate unique mutations are associated with distinct SDHI field efficacy profiles as shown in in-vitro sensitivity assays. Isolate populations with B subunit mutations (H267Y/R) were more sensitive to fluopyram, whereas isolate populations with C subunit mutations (C-G91R, C-G150R) showed resistance to all SDHIs tested. Mutation-associated differential sensitivity observed under field conditions indicates a need for a nation-wide survey and frequent monitoring of SDHI sensitivity of dollar spot populations on golf courses in the USA. Further, the information gained from this study will be useful in providing sustainable management recommendations for controlling site-specific resistant populations of Clarireedia spp.
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Affiliation(s)
- Jaemin Lee
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Michaela R Elliott
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Toshihiko Yamada
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 0606-0808, Japan
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
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Chou MY, Shrestha S, Rioux R, Koch P. Hyperlocal Variation in Soil Iron and the Rhizosphere Bacterial Community Determines Dollar Spot Development in Amenity Turfgrass. Appl Environ Microbiol 2021; 87:e00149-21. [PMID: 33741622 PMCID: PMC8117751 DOI: 10.1128/aem.00149-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/04/2021] [Indexed: 02/03/2023] Open
Abstract
Dollar spot, caused by the fungal pathogen Clarireedia spp., is an economically important foliar disease of amenity turfgrass in temperate climates worldwide. This disease often occurs in a highly variable manner, even on a local scale with relatively uniform environmental conditions. The objective of this study was to investigate mechanisms behind this local variation, focusing on contributions of the soil and rhizosphere microbiome. Turfgrass, rhizosphere, and bulk soil samples were collected from within a 256-m2 area of healthy turfgrass, transported to a controlled environment chamber, and inoculated with Clarireedia jacksonii Bacterial communities were profiled by targeting the 16S rRNA gene, and 16 different soil chemical properties were assessed. Despite their initial uniform appearance, the samples differentiated into highly susceptible and moderately susceptible groups following inoculation in the controlled environment chamber. The highly susceptible samples harbored a unique rhizosphere microbiome with suggestively lower relative abundance of putative antibiotic-producing bacterial taxa and higher predicted abundance of genes associated with xenobiotic biodegradation pathways. In addition, stepwise regression revealed that bulk soil iron content was the only significant soil characteristic that positively regressed with decreased dollar spot susceptibility during the peak disease development stage. These findings suggest that localized variation in soil iron induces the plant to select for a particular rhizosphere microbiome that alters the disease outcome. More broadly, further research in this area may indicate how plot-scale variability in soil properties can drive variable plant disease development through alterations in the rhizosphere microbiome.IMPORTANCE Dollar spot is the most economically important disease of amenity turfgrass, and more fungicides are applied targeting dollar spot than any other turfgrass disease. Dollar spot symptoms are small (3 to 5 cm), circular patches that develop in a highly variable manner within plot scale even under seemingly uniform conditions. The mechanism behind this variable development is unknown. This study observed that differences in dollar spot development over a 256-m2 area were associated with differences in bulk soil iron concentration and correlated with a particular rhizosphere microbiome. These findings provide interesting avenues for future research to further characterize the mechanisms behind the highly variable development of dollar spot, which may inform innovative control strategies. Additionally, these results suggest that small changes in soil properties can alter plant activity and hence the plant-associated microbial community, which has important implications for a broad array of agricultural and horticultural plant pathosystems.
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Affiliation(s)
- Ming-Yi Chou
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Smita Shrestha
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Renee Rioux
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Paul Koch
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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25
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Lee J, Elliott MR, Kim M, Yamada T, Jung G. A Rapid Molecular Detection System for SdhB and SdhC Point Mutations Conferring Differential Succinate Dehydrogenase Inhibitor Resistance in Clarireedia Populations. PLANT DISEASE 2021; 105:660-666. [PMID: 32757732 DOI: 10.1094/pdis-04-20-0724-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dollar spot, caused by the ascomycete fungus Clarireedia (formerly Sclerotinia), is one of the most resource-demanding diseases on amenity turfgrasses in North America. Differential resistance to the succinate dehydrogenase inhibitor (SDHI) fungicide class, conferred by singular point mutations on the SdhB, SdhC, and SdhD subunits of the succinate dehydrogenase enzyme (SDH), has been reported in dollar spot as well as many other plant-pathogenic fungal diseases. Four unique mutations were previously reported from Clarireedia field isolates collected from two different cool-season golf courses in Japan and Rhode Island: an amino acid substitution H267Y and a silent mutation (CTT to CTC) at codon 181 on the SdhB subunit gene, and amino acid substitutions G91R and G150R on the SdhC subunit gene. To properly diagnose and monitor SDHI resistance in the field, a rapid detection system for known mutations is crucial. As part of this study, additional SDHI-resistant Clarireedia isolates were collected from Rutgers University research plots and in vitro sensitivity to four SDHI active ingredients was assessed. SdhB, SdhC, and SdhD subunits of these isolates were sequenced to reveal an additional mutation on the SdhB subunit gene, H267R, not previously observed in Clarireedia. Cleaved amplified polymorphic sequence (CAPS) and derived CAPS molecular markers were developed to detect five mutations conferring SDHI resistance in Clarireedia isolates and validated using samples from two additional golf courses in Connecticut and Wisconsin experiencing SDHI field failure. This PCR-based molecular detection system will be useful for continued monitoring, assessment, and delay of SDHI resistance in the field.
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Affiliation(s)
- Jaemin Lee
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Michaela R Elliott
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Minsoo Kim
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Toshihiko Yamada
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 0606-0808, Japan
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, U.S.A
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26
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Hu M, Chen S. Non-Target Site Mechanisms of Fungicide Resistance in Crop Pathogens: A Review. Microorganisms 2021; 9:microorganisms9030502. [PMID: 33673517 PMCID: PMC7997439 DOI: 10.3390/microorganisms9030502] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 01/15/2023] Open
Abstract
The rapid emergence of resistance in plant pathogens to the limited number of chemical classes of fungicides challenges sustainability and profitability of crop production worldwide. Understanding mechanisms underlying fungicide resistance facilitates monitoring of resistant populations at large-scale, and can guide and accelerate the development of novel fungicides. A majority of modern fungicides act to disrupt a biochemical function via binding a specific target protein in the pathway. While target-site based mechanisms such as alternation and overexpression of target genes have been commonly found to confer resistance across many fungal species, it is not uncommon to encounter resistant phenotypes without altered or overexpressed target sites. However, such non-target site mechanisms are relatively understudied, due in part to the complexity of the fungal genome network. This type of resistance can oftentimes be transient and noninheritable, further hindering research efforts. In this review, we focused on crop pathogens and summarized reported mechanisms of resistance that are otherwise related to target-sites, including increased activity of efflux pumps, metabolic circumvention, detoxification, standing genetic variations, regulation of stress response pathways, and single nucleotide polymorphisms (SNPs) or mutations. In addition, novel mechanisms of drug resistance recently characterized in human pathogens are reviewed in the context of nontarget-directed resistance.
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Affiliation(s)
- Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742, USA
- Correspondence: (M.H.); (S.C.)
| | - Shuning Chen
- Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
- Correspondence: (M.H.); (S.C.)
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27
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Townsend R, Millican MD, Smith D, Nangle E, Hockemeyer K, Soldat D, Koch PL. Dollar Spot Suppression on Creeping Bentgrass in Response to Repeated Foliar Nitrogen Applications. PLANT DISEASE 2021; 105:276-284. [PMID: 32787654 DOI: 10.1094/pdis-05-20-1031-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Dollar spot is caused by the fungus Clarireedia spp. and is the most economically important disease of golf course turfgrass in temperate regions of the United States. Previous research has demonstrated that nitrogen (N) fertilization may reduce dollar spot severity, but the results have been inconsistent, and the impact of N as part of repeated foliar fertilization applications to golf course putting greens remains unclear. Two independent trials were replicated in Madison, Wisconsin and Glenview, Illinois in the 2015, 2016, and 2017 growing seasons. The objective of the first trial was to evaluate the effect of four different N rates applied as urea (4.9, 9.8, 19.4, and 29.3 kg N/ha applied every 2 weeks) on dollar spot severity, and the objective of the second trial was to evaluate the effect of three N sources (calcium nitrate, ammonium sulfate, and ammonium nitrate applied every 2 weeks) on dollar spot severity. Results from the N rate trial at both locations indicated that only the highest (29.3 kg N/ha) rate consistently reduced dollar spot severity relative to the nontreated control. Nitrogen source had minimal and inconsistent impacts on dollar spot severity based on location and year. Although these results show that meaningful reductions in dollar spot severity can be achieved by manipulating N fertilizer application rates, the rate of N needed for disease suppression may be impractical for most superintendents to apply and result in undesirable nontarget impacts.
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Affiliation(s)
- Ronald Townsend
- University of Wisconsin-Madison, Department of Plant Pathology, Madison, WI 53706
| | - Michael D Millican
- University of Minnesota, Department of Plant Pathology, St. Paul, MN 55108
| | - Damon Smith
- University of Wisconsin-Madison, Department of Plant Pathology, Madison, WI 53706
| | - Ed Nangle
- The Ohio State University, Wooster Campus, Wooster, OH 44691
| | - Kurt Hockemeyer
- University of Wisconsin-Madison, Department of Plant Pathology, Madison, WI 53706
| | - Doug Soldat
- University of Wisconsin-Madison, Department of Soil Science, Madison, WI 53706
| | - Paul L Koch
- University of Wisconsin-Madison, Department of Plant Pathology, Madison, WI 53706
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Cheng X, Man X, Wang Z, Liang L, Zhang F, Wang Z, Liu P, Lei B, Hao J, Liu X. Fungicide SYP-14288 Inducing Multidrug Resistance in Rhizoctonia solani. PLANT DISEASE 2020; 104:2563-2570. [PMID: 32762501 DOI: 10.1094/pdis-01-20-0048-re] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rhizoctonia solani is a widely distributed soilborne plant pathogen, and can cause significant economic losses to crop production. In chemical controls, SYP-14288 is highly effective against plant pathogens, including R. solani. To examine the sensitivity to SYP-14288, 112 R. solani isolates were collected from infected rice plants. An established baseline sensitivity showed that values of effective concentration for 50% growth inhibition (EC50) ranged from 0.0003 to 0.0138 μg/ml, with an average of 0.0055 ± 0.0030 μg/ml. The frequency distribution of the EC50 was unimodal and the range of variation factor (the ratio of maximal over minimal EC50) was 46.03, indicating that all wild-type strains were sensitive to SYP-14288. To examine the risk of fungicide resistance, 20 SYP-14288-resistant mutants were generated on agar plates amended with SYP-14288. Eighteen mutants remained resistant after 10 transfers, and their fitness was significantly different from the parental strain. All of the mutants grew more slowly but showed high virulence to rice plants, though lower than the parental strain. A cross-resistance assay demonstrated that there was a positive correlation between SYP-14288 and fungicides having or not having the same mode of action with SYP-14288, including fluazinam, fentin chloride, fludioxonil, difenoconazole, cyazofamid, chlorothalonil, and 2,4-dinitrophen. This result showed a multidrug resistance induced by SYP-14288, which could be a concern in increasing the spectrum of resistance in R. solani to commonly used fungicides.
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Affiliation(s)
- Xingkai Cheng
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Xuejing Man
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Zitong Wang
- College of Plant Protection, Northwest A&F University, Yangling 712100, China
| | - Li Liang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Fan Zhang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Zhiwen Wang
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Pengfei Liu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, China
| | - Bin Lei
- Institute of Nuclear and Biological Technologies, Xinjiang Academy of Agricultural Sciences, 403 Nanchang Road, Urumqi 830091, China
| | - Jianjun Hao
- School of Food and Agriculture, University of Maine, Orono, ME 04469, U.S.A
| | - Xili Liu
- College of Plant Protection, Northwest A&F University, Yangling 712100, China
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29
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Zhang L, Song L, Xu X, Zou X, Duan K, Gao Q. Characterization and Fungicide Sensitivity of Colletotrichum Species Causing Strawberry Anthracnose in Eastern China. PLANT DISEASE 2020; 104:1960-1968. [PMID: 32401619 DOI: 10.1094/pdis-10-19-2241-re] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Strawberry anthracnose caused by Colletotrichum spp. is one of the most serious diseases in the strawberry fields of China. In total, 196 isolates of Colletotrichum were obtained from leaves, stolons, and crowns of strawberry plants with anthracnose symptoms in eastern China and were characterized based on morphology, internal transcribed spacer (ITS), and β-tubulin (TUB2) gene sequences. All 196 isolates were identified as the Colletotrichum gloeosporioides species complex. In total, 62 strains were further identified at the species level by phylogenetic analyses of multilocus sequences of ITS, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), Apn2-Mat1-2 intergenic spacer and partial mating type (ApMat), calmodulin (CAL), and TUB2. Three species from the C. gloeosporioides species complex were identified: Colletotrichum siamense, C. fructicola, and C. aenigma. Isolates of C. siamense were tolerant to high temperatures, with a significantly larger colony diameter than the other two species when grown above 36°C. The inoculation of strawberry plants confirmed the pathogenicity of all three species. C. siamense isolates resulted in the highest disease severity. The in vitro sensitivities of C. siamense and C. fructicola isolates to azoxystrobin and three demethylation-inhibitor (DMI) fungicides (difenoconazole, tebuconazole, and prochloraz) were determined. Both species were sensitive to DMI fungicides but not to azoxystrobin. C. siamense isolates were more sensitive to prochloraz, while C. fructicola isolates were more sensitive to difenoconazole and tebuconazole. The present study provides valuable information for the effective management of strawberry anthracnose.
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Affiliation(s)
- Liqing Zhang
- Shanghai Key Laboratory of Protected Horticultural Technology, Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
- Shanghai Agricultural Seed & Seedling Co., Ltd
| | - Lili Song
- College of Food Science, Shanghai Ocean University, Shanghai 201306, China
| | - Xiangming Xu
- NIAB EMR, New Road, East Malling, Kent ME19 6BJ, U.K
| | - Xiaohua Zou
- Shanghai Key Laboratory of Protected Horticultural Technology, Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
| | - Ke Duan
- Shanghai Key Laboratory of Protected Horticultural Technology, Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
- College of Food Science, Shanghai Ocean University, Shanghai 201306, China
| | - Qinghua Gao
- Shanghai Key Laboratory of Protected Horticultural Technology, Forestry and Fruit Tree Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai 201403, China
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30
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MFS transporter from Botrytis cinerea provides tolerance to glucosinolate-breakdown products and is required for pathogenicity. Nat Commun 2019; 10:2886. [PMID: 31253809 PMCID: PMC6599007 DOI: 10.1038/s41467-019-10860-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 06/04/2019] [Indexed: 01/03/2023] Open
Abstract
Glucosinolates accumulate mainly in cruciferous plants and their hydrolysis-derived products play important roles in plant resistance against pathogens. The pathogen Botrytis cinerea has variable sensitivity to glucosinolates, but the mechanisms by which it responds to them are mostly unknown. Exposure of B. cinerea to glucosinolate-breakdown products induces expression of the Major Facilitator Superfamily transporter, mfsG, which functions in fungitoxic compound efflux. Inoculation of B. cinerea on wild-type Arabidopsis thaliana plants induces mfsG expression to higher levels than on glucosinolate-deficient A. thaliana mutants. A B. cinerea strain lacking functional mfsG transporter is deficient in efflux ability. It accumulates more isothiocyanates (ITCs) and is therefore more sensitive to this compound in vitro; it is also less virulent to glucosinolates-containing plants. Moreover, mfsG mediates ITC efflux in Saccharomyces cerevisiae cells, thereby conferring tolerance to ITCs in the yeast. These findings suggest that mfsG transporter is a virulence factor that increases tolerance to glucosinolates. Plant glucosinolates are important in defense against fungal pathogens. Here, the authors identify a major facilitator superfamily transporter protein of the pathogen Botrytis cinerea, mfsG, that plays a role in efflux and detoxification of glucosinolate-breakdown products during plant–pathogen interactions.
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Hu J, Zhou Y, Gao T, Geng J, Dai Y, Ren H, Lamour K, Liu X. Resistance risk assessment for fludioxonil in Sclerotinia homoeocarpa in China. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2019; 156:123-128. [PMID: 31027571 DOI: 10.1016/j.pestbp.2019.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 01/23/2019] [Accepted: 02/11/2019] [Indexed: 06/09/2023]
Abstract
Sclerotinia homoeocarpa causes dollar spot disease on turfgrass and is a serious problem on many species worldwide. Fludioxonil, a phenylpyrrole fungicide, is not currently registered for dollar spot control in China. In this study, the baseline sensitivity to fludioxonil was established using an in vitro assay for 105 isolates of S. homoeocarpa collected from 10 locations in different regions of China. Results indicate that the frequency distribution of effective concentration for 50% inhibition of mycelial growth (EC50) values of the S. homoeocarpa isolates was unimodal (W = 0.9847, P = .2730). The mean EC50 value was 0.0020 ± 0.0006 μg/ml with a range from 0.0003 to 0.0035 μg/ml. A total of 7 fludioxonil-resistant mutants were obtained in laboratory, the mutants were stable in fludioxonil sensitivity after the 10th transfer, with resistance factor (RF) ranging from 4.320 to >13,901.4. The mutants showed a positive cross-resistance between fludioxonil and the dicarboximide fungicide iprodione, but not propiconazole, fluazinam, and thiophanate-methyl. When mycelial growth rate, pathogenicity and osmotic sensitivity were assessed, the mutants decreased in the fitness compared with their parental isolates. Sequence alignment of the histidine kinase gene Shos1 revealed a 13-bp fragment deletion only in one mutant, no mutations were observed on Shos1 in the rest resistant mutants.
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Affiliation(s)
- Jian Hu
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Yuxin Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Tao Gao
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Jiamei Geng
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yuan Dai
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Haiyan Ren
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville 37996, USA
| | - Xili Liu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, PR China
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32
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Sang H, Popko JT, Jung G. Evaluation of a Sclerotinia homoeocarpa Population with Multiple Fungicide Resistance Phenotypes Under Differing Selection Pressures. PLANT DISEASE 2019; 103:685-690. [PMID: 30702386 DOI: 10.1094/pdis-06-18-1080-re] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dollar spot, caused by Sclerotinia homoeocarpa, is one of the most significant diseases of cool-season turfgrass on golf courses. Resistance to the benzimidazole, dicarboximide, and succinate dehydrogenase inhibitor (SDHI) classes and reduced sensitivity to the sterol-demethylation inhibitor (DMI) in S. homoeocarpa populations have been widely reported in the United States. Moreover, the occurrence of S. homoeocarpa populations with multiple fungicide resistance (MFR) is a growing problem on golf courses. The present study was undertaken to evaluate the efficacy of DMI, dicarboximide, and SDHI against a S. homoeocarpa population with MFR on a Connecticut golf course fairway from 2014 to 2016. Also, because the S. homoeocarpa population consisted of four different phenotypes with differing resistance profiles to benzimidazole, dicarboximide, and DMI, in vitro sensitivity assays were used to understand the dynamics of the MFR population in the presence and absence of fungicide selection pressures. Results indicated that boscalid fungicide (SDHI) was able to provide an acceptable control of the MFR dollar spot population. Propiconazole or iprodione application selected isolates with both DMI and dicarboximide resistance (DMI-R/Dicar-R). In the absence of fungicide selection pressures, the percent frequency of DMI-R/Dicar-R or DMI and benzimidazole resistance (DMI-R/Ben-R) isolates declined in the population. Out of the four phenotypes, the percent frequency of isolates with DMI, dicarboximide, and benzimidazole resistance (DMI-R/Dicar-R/Ben-R) was the lowest in the population regardless of fungicide selection pressures. Our first report of MFR population dynamics will help develop effective strategies for managing MFR and potentially delay the emergence of future resistant populations in S. homoeocarpa.
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Affiliation(s)
- Hyunkyu Sang
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - James T Popko
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
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Stephens CM, Kaminski J. In Vitro Fungicide-Insensitive Profiles of Sclerotinia homoeocarpa Populations from Pennsylvania and the Surrounding Region. PLANT DISEASE 2019; 103:214-222. [PMID: 30501462 DOI: 10.1094/pdis-07-18-1149-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Repeated fungicide applications are typically required to provide adequate control of dollar spot on golf courses and may shift Sclerotinia homoeocarpa populations from sensitive to insensitive or resistant to an active ingredient. The objective of this study was to characterize the geographic distribution of fungicide-insensitive, fungicide-resistant, and multiple fungicide insensitive (MFI) S. homoeocarpa populations on golf courses in Pennsylvania and the surrounding region. S. homoeocarpa isolates (n = 681) were collected from 45 different golf courses or research facilities. Each isolate was evaluated in vitro against propiconazole, iprodione, boscalid, and thiophanate-methyl using discriminatory concentrations of 0.1, 1.0, 1,000, and 1,000 µg of active ingredient per milliliter of PDA, respectively. Relative mycelial growth (RMG) values were used to determine sensitivity or insensitivity based on comparison with a baseline population. Of the 681 isolates evaluated, 81, 80, and 85% exhibited reduced sensitivity to boscalid, iprodione, and propiconazole, respectively. A total of 41% of the isolates were resistant to thiophanate-methyl. Based on mean RMG of all isolates from each golf course, 16, 35, and 37 of the 45 golf courses exhibited reduced sensitivity to boscalid, iprodione, and propiconazole, respectively. A total of 585 isolates (86%) exhibited an MFI profile in which they were insensitive or resistant to at least two fungicides evaluated. Isolates with reduced sensitivity to boscalid, iprodione, and propiconazole, but sensitive to thiophanate-methyl, were the most common phenotype within the three-MFI profile. Fungicide insensitivity and resistance to commonly used fungicides, as well as MFI profiles, were prevalent in Pennsylvania and the surrounding areas and may cause management challenges.
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Affiliation(s)
- Cameron M Stephens
- Department of Plant Science, The Pennsylvania State University, University Park 16802
| | - John Kaminski
- Department of Plant Science, The Pennsylvania State University, University Park 16802
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Popko JT, Sang H, Lee J, Yamada T, Hoshino Y, Jung G. Resistance of Sclerotinia homoeocarpa Field Isolates to Succinate Dehydrogenase Inhibitor Fungicides. PLANT DISEASE 2018; 102:2625-2631. [PMID: 30307834 DOI: 10.1094/pdis-12-17-2025-re] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Sclerotinia homoeocarpa isolates were collected from golf courses in Japan and the United States (2016-2017). Japan isolates were collected during a monitoring study and the U.S. isolates were collected due to field failure. Five succinate dehydrogenase inhibitor (SDHI) active ingredients (boscalid, fluopyram, fluxapyroxad, isofetamid, and penthiopyrad) were examined using in vitro sensitivity assays to determine cross-resistance. Sequence analysis revealed a point mutation leading to an amino acid substitution (H267Y) and a silent mutation (CTT to CTC) at codon 181 in the SdhB subunit gene. Isolates with the B-H267Y (n = 10) mutation were resistant to boscalid and penthiopyrad and had increased sensitivity to fluopyram. SdhB silent mutation 181C>T isolates (n = 2) were resistant to boscalid, isofetamid, and penthiopyrad. Sequence analysis revealed 3 mutations leading to an amino acid substitution (G91R, n = 5; G150R, n = 1; G159W, n = 1) in the SdhC subunit gene. Isolates harboring the SdhC (G91R or G150R) mutations were resistant to boscalid, fluxapyroxad, isofetamid, and penthiopyrad. A genetic transformation system was used to generate mutants from a SDHI sensitive isolate to confirm the B-H267Y and C-G91R mutations were direct determinants of SDHI resistance and associated with in vitro sensitivity assay results.
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Affiliation(s)
- James T Popko
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - Hyunkyu Sang
- Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI 48824
| | - Jaemin Lee
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003
| | - Toshihiko Yamada
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 0606-0808, Japan
| | - Yoichiro Hoshino
- Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 0606-0808, Japan
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003; and Field Science Center for Northern Biosphere, Hokkaido University, Sapporo, Hokkaido 0606-0808, Japan
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Hu J, Deng S, Gao T, Lamour K, Liu X, Ren H. Thiophanate-methyl resistance in Sclerotinia homoeocarpa from golf courses in China. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2018; 152:84-89. [PMID: 30497716 DOI: 10.1016/j.pestbp.2018.09.004] [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: 06/02/2018] [Revised: 08/15/2018] [Accepted: 09/13/2018] [Indexed: 06/09/2023]
Abstract
Sclerotinia homoeocarpa causes dollar spot disease on many turfgrass species and is a significant problem worldwide. Thiophanate-methyl (TM), a methyl benzimidazole carbamate (MBC) fungicide, has been used for over forty years to manage dollar spot. Here we describe genetic mutations linked to three distinct TM fungicide resistance phenotypes: sensitive (S), moderately resistant (MR) and highly resistant (HR). These were established using multiple doses of TM, compared to previous studies using single discriminatory doses. In total, 19 S, 3 MR and 22 HR isolates were detected. Analysis of the β-tubulin gene revealed the MR isolates had a point mutation from T to A at codon 200 changing phenylalanine (TTC) to tyrosine (TAC). Twenty HR isolates had a mutation at codon 198 changing glutamic acid (GAG) to alanine (GCG) and two HR isolates had a mutation at codon 198 changing glutamic acid (GAG) to lysine (AAG). Allele-specific PCR assays were developed for rapid detection of these mutations in isolates of S. homoeocarpa. In addition, our results suggest a two-dose system for in vitro screening provides useful information for monitoring the development of resistance.
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Affiliation(s)
- Jian Hu
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Shaojun Deng
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Tao Gao
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Kurt Lamour
- Department of Entomology and Plant Pathology, University of Tennessee, Knoxville 37996, USA
| | - Xili Liu
- Department of Plant Pathology, China Agricultural University, Beijing 100193, PR China
| | - Haiyan Ren
- College of Agro-grassland Science, Nanjing Agricultural University, Nanjing 210095, PR China.
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Sang H, Witte A, Jacobs JL, Chang HX, Wang J, Roth MG, Chilvers MI. Fluopyram Sensitivity and Functional Characterization of SdhB in the Fusarium solani Species Complex Causing Soybean Sudden Death Syndrome. Front Microbiol 2018; 9:2335. [PMID: 30327645 PMCID: PMC6174223 DOI: 10.3389/fmicb.2018.02335] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 09/12/2018] [Indexed: 11/25/2022] Open
Abstract
The succinate dehydrogenase inhibitor (SDHI) fungicide, fluopyram, is used as a soybean seed treatment to manage Fusarium virguliforme, the casual agent of sudden death syndrome (SDS). More recently, other species within clade 2 of the Fusarium solani species, F. tucumaniae in South America and F. brasiliense in America and Africa, have been recognized as additional agents capable of causing SDS. To determine if fluopyram could be used for management of SDS caused by these species, in vitro sensitivity tests of the three Fusarium species to fluopyram were conducted. The mean EC50 values of F. brasiliense and F. virguliforme strains to fluopyram were 1.96 and 2.21 μg ml-1, respectively, but interestingly F. tucumaniae strains were highly sensitive (mean EC50 = 0.25 μg ml-1) to fluopyram compared to strains of the other two species. A sequence analysis of Sdh genes of Fusarium strains revealed that the F. tucumaniae strains contain an arginine at codon 277 in the SdhB gene instead of a glycine as in other Fusarium species. Replacement of glycine to arginine in SdhB-277 in a F. virguliforme wild-type strain Mont-1 through genetic transformation resulted in increased sensitivity to two SDHI fungicides, fluopyram and boscalid. Similar to a F. tucumaniae strain, the Mont-1 (SdhBG277R) mutant caused less SDS and root rot disease than Mont-1 on soybean seedlings with the fluopyram seed treatment. Our study suggests the amino acid difference in the SdhB in F. tucumaniae results in fluopyram being efficacious if used as a seed treatment for management of F. tucumaniae, which is the most abundant SDS causing species in South America. The establishment of baseline sensitivity of Fusarium species to fluopyram will contribute to effective strategies for managing Fusarium diseases in soybean and other pathosystems such as dry bean.
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Affiliation(s)
- Hyunkyu Sang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Alexander Witte
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Janette L. Jacobs
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Hao-Xun Chang
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
| | - Jie Wang
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States
| | - Mitchell G. Roth
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
- Genetics Graduate Program, Michigan State University, East Lansing, MI, United States
| | - Martin I. Chilvers
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, United States
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Sang H, Hulvey JP, Green R, Xu H, Im J, Chang T, Jung G. A Xenobiotic Detoxification Pathway through Transcriptional Regulation in Filamentous Fungi. mBio 2018; 9:e00457-18. [PMID: 30018104 PMCID: PMC6050962 DOI: 10.1128/mbio.00457-18] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 06/22/2018] [Indexed: 12/12/2022] Open
Abstract
Fungi are known to utilize transcriptional regulation of genes that encode efflux transporters to detoxify xenobiotics; however, to date it is unknown how fungi transcriptionally regulate and coordinate different phases of detoxification system (phase I, modification; phase II, conjugation; and phase III, secretion). Here we present evidence of an evolutionary convergence between the fungal and mammalian lineages, whereby xenobiotic detoxification genes (phase I coding for cytochrome P450 monooxygenases [CYP450s] and phase III coding for ATP-binding cassette [ABC] efflux transporters) are transcriptionally regulated by structurally unrelated proteins. Following next-generation RNA sequencing (RNA-seq) analyses of a filamentous fungus, Sclerotinia homoeocarpa, the causal agent of dollar spot on turfgrasses, a multidrug resistant (MDR) field strain was found to overexpress phase I and III genes, coding for CYP450s and ABC transporters for xenobiotic detoxification. Furthermore, there was confirmation of a gain-of-function mutation of the fungus-specific transcription factor S. homoeocarpa XDR1 (ShXDR1), which is responsible for constitutive and induced overexpression of the phase I and III genes, resulting in resistance to multiple classes of fungicidal chemicals. This fungal pathogen detoxifies xenobiotics through coordinated transcriptional control of CYP450s, biotransforming xenobiotics with different substrate specificities and ABC transporters, excreting a broad spectrum of xenobiotics or biotransformed metabolites. A Botrytis cinerea strain harboring the mutated ShXDR1 showed increased expression of phase I (BcCYP65) and III (BcatrD) genes, resulting in resistance to fungicides. This indicates the regulatory system is conserved in filamentous fungi. This molecular genetic mechanism for xenobiotic detoxification in fungi holds potential for facilitating discovery of new antifungal drugs and further studies of convergent and divergent evolution of xenobiotic detoxification in eukaryote lineages.IMPORTANCE Emerging multidrug resistance (MDR) in pathogenic filamentous fungi is a significant threat to human health and agricultural production. Understanding mechanisms of MDR is essential to combating fungal pathogens; however, there is still limited information on MDR mechanisms conferred by xenobiotic detoxification. Here, we report for the first time that overexpression of phase I drug-metabolizing monooxygenases (cytochrome P450s) and phase III ATP-binding cassette efflux transporters is regulated by a gain-of-function mutation in the fungus-specific transcription factor in the MDR strains of the filamentous plant-pathogenic fungus Sclerotinia homoeocarpa This study establishes a novel molecular mechanism of MDR through the xenobiotic detoxification pathway in filamentous fungi, which may facilitate the discovery of new antifungal drugs to control pathogenic fungi.
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Affiliation(s)
- Hyunkyu Sang
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jonathan P Hulvey
- Department of Biology, Eastern Connecticut State University, Willimantic, Connecticut, USA
| | - Robert Green
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Hao Xu
- School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jeongdae Im
- Department of Civil Engineering, Kansas State University, Manhattan, Kansas, USA
| | - Taehyun Chang
- School of Ecology and Environmental System, Kyungpook National University, Sangju, South Korea
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
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Hellin P, King R, Urban M, Hammond-Kosack KE, Legrève A. The adaptation of Fusarium culmorum to DMI Fungicides Is Mediated by Major Transcriptome Modifications in Response to Azole Fungicide, Including the Overexpression of a PDR Transporter (FcABC1). Front Microbiol 2018; 9:1385. [PMID: 29997598 PMCID: PMC6028722 DOI: 10.3389/fmicb.2018.01385] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/06/2018] [Indexed: 11/13/2022] Open
Abstract
Fusarium culmorum is a fungal pathogen causing economically important diseases on a variety of crops. Fungicides can be applied to control this species with triazoles being the most efficient molecules. F. culmorum strains resistant to these molecules have been reported, but the underlying resistance mechanisms remain unknown. In this study, a tebuconazole-adapted F. culmorum strain was developed with a level of fitness similar to its parental strain. The adapted strain showed cross-resistance to all demethylation inhibitors (DMIs), but not to other classes of fungicides tested. RNA-Seq analysis revealed high transcriptomic differences between the resistant strain and its parental strain after tebuconazole treatment. Among these changes, FcABC1 (FCUL_06717), a pleiotropic drug resistance transporter, had a 30-fold higher expression level upon tebuconazole treatment in the adapted strains as compared to the wild-type strain. The implication of this transporter in triazole resistance was subsequently confirmed in field strains harboring distinct levels of sensitivity to triazoles. FcABC1 is present in other species/genera, including F. graminearum in which it is known to be necessary for azole resistance. No difference in FcABC1 sequences, including the surrounding regions, were found when comparing the resistant strain to the wild-type strain. Fusarium culmorum is therefore capable to adapt to triazole pressure by overexpressing a drug resistance transporter when submitted to triazoles and the same mechanism is anticipated to occur in other species.
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Affiliation(s)
- Pierre Hellin
- Earth and Life Institute, Applied Microbiology, Phytopathology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
| | - Robert King
- Department of Computational and Systems Biology, Rothamsted Research, Harpenden, United Kingdom
| | - Martin Urban
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Kim E. Hammond-Kosack
- Department of Biointeractions and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Anne Legrève
- Earth and Life Institute, Applied Microbiology, Phytopathology, Université Catholique de Louvain, Louvain-la-Neuve, Belgium
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Nucleic adaptability of heterokaryons to fungicides in a multinucleate fungus, Sclerotinia homoeocarpa. Fungal Genet Biol 2018; 115:64-77. [DOI: 10.1016/j.fgb.2018.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 12/01/2017] [Accepted: 01/10/2018] [Indexed: 10/18/2022]
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Plasticity of the MFS1 Promoter Leads to Multidrug Resistance in the Wheat Pathogen Zymoseptoria tritici. mSphere 2017; 2:mSphere00393-17. [PMID: 29085913 PMCID: PMC5656749 DOI: 10.1128/msphere.00393-17] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 09/21/2017] [Indexed: 11/20/2022] Open
Abstract
The ascomycete Zymoseptoria tritici is the causal agent of Septoria leaf blotch on wheat. Disease control relies mainly on resistant wheat cultivars and on fungicide applications. The fungus displays a high potential to circumvent both methods. Resistance against all unisite fungicides has been observed over decades. A different type of resistance has emerged among wild populations with multidrug-resistant (MDR) strains. Active fungicide efflux through overexpression of the major facilitator gene MFS1 explains this emerging resistance mechanism. Applying a bulk-progeny sequencing approach, we identified in this study a 519-bp long terminal repeat (LTR) insert in the MFS1 promoter, a relic of a retrotransposon cosegregating with the MDR phenotype. Through gene replacement, we show the insert as a mutation responsible for MFS1 overexpression and the MDR phenotype. Besides this type I insert, we found two different types of promoter inserts in more recent MDR strains. Type I and type II inserts harbor potential transcription factor binding sites, but not the type III insert. Interestingly, all three inserts correspond to repeated elements present at different genomic locations in either IPO323 or other Z. tritici strains. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici and which contribute to its adaptive potential. IMPORTANCE Disease control through fungicides remains an important means to protect crops from fungal diseases and to secure the harvest. Plant-pathogenic fungi, especially Zymoseptoria tritici, have developed resistance against most currently used active ingredients, reducing or abolishing their efficacy. While target site modification is the most common resistance mechanism against single modes of action, active efflux of multiple drugs is an emerging phenomenon in fungal populations reducing additionally fungicides' efficacy in multidrug-resistant strains. We have investigated the mutations responsible for increased drug efflux in Z. tritici field strains. Our study reveals that three different insertions of repeated elements in the same promoter lead to multidrug resistance in Z. tritici. The target gene encodes the membrane transporter MFS1 responsible for drug efflux, with the promoter inserts inducing its overexpression. These results underline the plasticity of repeated elements leading to fungicide resistance in Z. tritici.
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Cao X, Xu X, Che H, West JS, Luo D. Distribution and Fungicide Sensitivity of Colletotrichum Species Complexes from Rubber Tree in Hainan, China. PLANT DISEASE 2017; 101:1774-1780. [PMID: 30676918 DOI: 10.1094/pdis-03-17-0352-re] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Colletotrichum gloeosporioides and C. acutatum species complexes are causal agents of Colletotrichum leaf disease (CLD) of rubber trees worldwide. To determine the geographic distribution of Colletotrichum species complexes associated with CLD of rubber trees in Hainan, China, and their sensitivity to fungicides used in the region, a total of 275 Colletotrichum isolates were collected from 52 rubber tree plantations in 11 counties. These isolates were identified based jointly on morphological characteristics and PCR-based methodology. Of these isolates, 78 and 22% belonged to the C. gloeosporioides species complex (CGSC) and the C. acutatum complex (CASC), respectively. The incidence of CGSC isolates was greater than the CASC in all counties sampled. The incidence of CASC isolates appeared to be lower in the western and central south of Hainan than in other regions. There was no association in their presence at a given plantation between the two species complexes. The in vitro sensitivity of these two species complexes to carbendazim, chlorothalonil, and four demethylation inhibitor (DMI) fungicides (difenoconazole, propiconazole, myclobutanil, and prochloraz) was determined. Carbendazim was effective against CGSC but not against CASC with mean ED50 values of 0.176 and 2.182 µg/ml, respectively. CASC isolates were more sensitive to difenoconazole, propiconazole, and myclobutanil (mean ED50 values of 0.177, 0.129, and 1.424 µg/ml, respectively) than CGSC isolates (mean ED50 values of 0.710, 0.348, and 3.496 µg/ml, respectively). Mean ED50 values of CGSC against chlorothalonil and prochloraz were 173.341 and 0.035 µg/ml, respectively; corresponding values for CASC were 151.441 and 0.040 µg/ml. These results suggest that prochloraz, propiconazole, and difenoconazole are effective against both species complexes.
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Affiliation(s)
- Xueren Cao
- Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | - Xiangming Xu
- NIAB East Malling Research, New Road, East Malling, Kent ME19 6BJ, U.K
| | - Haiyan Che
- Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
| | | | - Daquan Luo
- Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou 571101, China
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Kumar Tripathy M, Weeraratne G, Clark G, Roux SJ. Apyrase inhibitors enhance the ability of diverse fungicides to inhibit the growth of different plant-pathogenic fungi. MOLECULAR PLANT PATHOLOGY 2017; 18:1012-1023. [PMID: 27392542 PMCID: PMC6638264 DOI: 10.1111/mpp.12458] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/24/2016] [Accepted: 07/06/2016] [Indexed: 06/06/2023]
Abstract
A previous study has demonstrated that the treatment of Arabidopsis plants with chemical inhibitors of apyrase enzymes increases their sensitivity to herbicides. In this study, we found that the addition of the same or related apyrase inhibitors could potentiate the ability of different fungicides to inhibit the growth of five different pathogenic fungi in plate growth assays. The growth of all five fungi was partially inhibited by three commonly used fungicides: copper octanoate, myclobutanil and propiconazole. However, when these fungicides were individually tested in combination with any one of four different apyrase inhibitors (AI.1, AI.10, AI.13 or AI.15), their potency to inhibit the growth of five fungal pathogens was increased significantly relative to their application alone. The apyrase inhibitors were most effective in potentiating the ability of copper octanoate to inhibit fungal growth, and least effective in combination with propiconazole. Among the five pathogens assayed, that most sensitive to the fungicide-potentiating effects of the inhibitors was Sclerotinia sclerotiorum. Overall, among the 60 treatment combinations tested (five pathogens, four apyrase inhibitors, three fungicides), the addition of apyrase inhibitors increased significantly the sensitivity of fungi to the fungicide treatments in 53 of the combinations. Consistent with their predicted mode of action, inhibitors AI.1, AI.10 and AI.13 each increased the level of propiconazole retained in one of the fungi, suggesting that they could partially block the ability of efflux transporters to remove propiconazole from these fungi.
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Affiliation(s)
- Manas Kumar Tripathy
- Department of Molecular BiosciencesUniversity of Texas at AustinAustinTX78712USA
| | - Gayani Weeraratne
- Department of Molecular BiosciencesUniversity of Texas at AustinAustinTX78712USA
| | - Greg Clark
- Department of Molecular BiosciencesUniversity of Texas at AustinAustinTX78712USA
| | - Stanley J. Roux
- Department of Molecular BiosciencesUniversity of Texas at AustinAustinTX78712USA
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Ruan R, Wang M, Liu X, Sun X, Chung KR, Li H. Functional analysis of two sterol regulatory element binding proteins in Penicillium digitatum. PLoS One 2017; 12:e0176485. [PMID: 28467453 PMCID: PMC5415137 DOI: 10.1371/journal.pone.0176485] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/11/2017] [Indexed: 12/05/2022] Open
Abstract
The sterol regulatory element binding proteins (SREBPs) are key regulators for sterol homeostasis in most fungi. In the citrus postharvest pathogen Penicillium digitatum, the SREBP homolog is required for fungicide resistance and regulation of CYP51 expression. In this study, we identified another SREBP transcription factor PdSreB in P. digitatum, and the biological functions of both SREBPs were characterized and compared. Inactivation of PdsreA, PdsreB or both genes in P. digitatum reduced ergosterol contents and increased sensitivities to sterol 14-α-demethylation inhibitors (DMIs) and cobalt chloride. Fungal strains impaired at PdsreA but not PdsreB increased sensitivity to tridemorph and an iron chelator 2,2'-dipyridyl. Virulence assays on citrus fruit revealed that fungal strains impaired at PdsreA, PdsreB or both induce maceration lesions similar to those induced by wild-type. However, ΔPdsreA, ΔPdsreB or the double mutant strain rarely produce aerial mycelia on infected citrus fruit peels. RNA-Seq analysis showed the broad regulatory functions of both SREBPs in biosynthesis, transmembrane transportation and stress responses. Our results provide new insights into the conserved and differentiated regulatory functions of SREBP homologs in plant pathogenic fungi.
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Affiliation(s)
- Ruoxin Ruan
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Mingshuang Wang
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xin Liu
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Xuepeng Sun
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
| | - Kuang-Ren Chung
- Department of Plant Pathology, National Chung-Hsing University, Taichung, Taiwan
| | - Hongye Li
- Institute of Biotechnology, Zhejiang University, Hangzhou, China
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Li J, Sang H, Guo H, Popko JT, He L, White JC, Parkash Dhankher O, Jung G, Xing B. Antifungal mechanisms of ZnO and Ag nanoparticles to Sclerotinia homoeocarpa. NANOTECHNOLOGY 2017; 28:155101. [PMID: 28294107 DOI: 10.1088/1361-6528/aa61f3] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Fungicides have extensively been used to effectively combat fungal diseases on a range of plant species, but resistance to multiple active ingredients has developed in pathogens such as Sclerotinia homoeocarpa, the causal agent of dollar spot on cool-season turfgrasses. Recently, ZnO and Ag nanoparticles (NPs) have received increased attention due to their antimicrobial activities. In this study, the NPs' toxicity and mechanisms of action were investigated as alternative antifungal agents against S. homoeocarpa isolates that varied in their resistance to demethylation inhibitor (DMI) fungicides. S. homoeocarpa isolates were treated with ZnO NPs and ZnCl2 (25-400 μg ml-1) and Ag NPs and AgNO3 (5-100 μg ml-1) to test antifungal activity of the NPs and ions. The mycelial growth of S. homoeocarpa isolates regardless of their DMI sensitivity was significantly inhibited on ZnO NPs (≥200 μg ml-1), Ag NPs (≥25 μg ml-1), Zn2+ ions (≥200 μg ml-1), and Ag+ ions (≥10 μg ml-1) amended media. Expression of stress response genes, glutathione S-transferase (Shgst1) and superoxide dismutase 2 (ShSOD2), was significantly induced in the isolates by exposure to the NPs and ions. In addition, a significant increase in the nucleic acid contents of fungal hyphae, which may be due to stress response, was observed upon treatment with Ag NPs using Raman spectroscopy. We further observed that a zinc transporter (Shzrt1) might play an important role in accumulating ZnO and Ag NPs into the cells of S. homoeocarpa due to overexpression of Shzrt1 significantly induced by ZnO or Ag NPs within 3 h of exposure. Yeast mutants complemented with Shzrt1 became more sensitive to ZnO and Ag NPs as well as Zn2+ and Ag+ ions than the control strain and resulted in increased Zn or Ag content after exposure. This is the first report of involvement of the zinc transporter in the accumulation of Zn and Ag from NP exposure in filamentous plant pathogenic fungi. Understanding the molecular mechanisms of NPs' antifungal activities will be useful in developing effective management strategies to control important pathogenic fungal diseases.
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Affiliation(s)
- Junli Li
- Stockbridge School of Agriculture, University of Massachusetts, 161 Holdsworth Way, Amherst, MA 01003, United States of America. School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, People's Republic of China
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Sang H, Popko JT, Chang T, Jung G. Molecular Mechanisms Involved in Qualitative and Quantitative Resistance to the Dicarboximide Fungicide Iprodione in Sclerotinia homoeocarpa Field Isolates. PHYTOPATHOLOGY 2017; 107:198-207. [PMID: 27642797 DOI: 10.1094/phyto-05-16-0211-r] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The dicarboximide fungicide class is commonly used to control Sclerotinia homoeocarpa, the causal agent of dollar spot on turfgrass. Despite frequent occurrences of S. homoeocarpa field resistance to iprodione (dicarboximide active ingredient), the genetic mechanisms of iprodione resistance have not been elucidated. In this study, 15 field isolates (seven suspected dicarboximide resistant, three multidrug resistance (MDR)-like, and five dicarboximide sensitive) were used for sequence comparison of a histidine kinase gene, Shos1, of S. homoeocarpa. The suspected dicarboximide-resistant isolates displayed nonsynonymous polymorphisms in codon 366 (isoleucine to asparagine) in Shos1, while the MDR-like and sensitive isolates did not. Further elucidation of the Shos1 function, using polyethylene glycol-mediated protoplast transformation indicated that S. homoeocarpa mutants (Shos1I366N) from a sensitive isolate gained resistance to dicarboximides but not phenylpyrrole and polyols. The deletion of Shos1 resulted in higher resistance to dicarboximide and phenylpyrrole and higher sensitivity to polyols than Shos1I366N. Levels of dicarboximide sensitivity in the sensitive isolate, Shos1I366N, and Shos1 deletion mutants were negatively correlated to values of iprodione-induced expression of ShHog1, the last kinase in the high-osmolarity glycerol pathway. Increased constitutive and induced expression of the ATP-binding cassette multidrug efflux transporter ShPDR1 was observed in six of seven dicarboximide-resistant isolates. In conclusion, S. homoeocarpa field isolates gained dicarboximide resistance through the polymorphism in Shos1 and the overexpression of ShPDR1.
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Affiliation(s)
- Hyunkyu Sang
- First, second, and fourth authors: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003; and third author: School of Ecology and Environmental System, College of Ecology and Environmental Science, Kyungpook National University, Sangju, 742-711, Korea
| | - James T Popko
- First, second, and fourth authors: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003; and third author: School of Ecology and Environmental System, College of Ecology and Environmental Science, Kyungpook National University, Sangju, 742-711, Korea
| | - Taehyun Chang
- First, second, and fourth authors: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003; and third author: School of Ecology and Environmental System, College of Ecology and Environmental Science, Kyungpook National University, Sangju, 742-711, Korea
| | - Geunhwa Jung
- First, second, and fourth authors: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003; and third author: School of Ecology and Environmental System, College of Ecology and Environmental Science, Kyungpook National University, Sangju, 742-711, Korea
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46
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Green R, Sang H, Chang T, Allan-Perkins E, Petit E, Jung G. Draft Genome Sequences of the Turfgrass Pathogen Sclerotinia homoeocarpa. GENOME ANNOUNCEMENTS 2016; 4:e01715-15. [PMID: 26868400 PMCID: PMC4751324 DOI: 10.1128/genomea.01715-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 12/21/2015] [Indexed: 11/20/2022]
Abstract
Sclerotinia homoeocarpa (F. T. Bennett) is one of the most economically important pathogens on high-amenity cool-season turfgrasses, where it causes dollar spot. To understand the genetic mechanisms of fungicide resistance, which has become highly prevalent, the whole genomes of two isolates with varied resistance levels to fungicides were sequenced.
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Affiliation(s)
- Robert Green
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Hyunkyu Sang
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Taehyun Chang
- School of Ecology & Environmental System, Kyungpook National University, Sangju, Gyeongbuk, South Korea
| | - Elisha Allan-Perkins
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Elsa Petit
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
| | - Geunhwa Jung
- Stockbridge School of Agriculture, University of Massachusetts, Amherst, Massachusetts, USA
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Panapruksachat S, Iwatani S, Oura T, Vanittanakom N, Chindamporn A, Niimi K, Niimi M, Lamping E, Cannon RD, Kajiwara S. Identification and functional characterization of Penicillium marneffei pleiotropic drug resistance transporters ABC1 and ABC2. Med Mycol 2016; 54:478-91. [PMID: 26782644 DOI: 10.1093/mmy/myv117] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2015] [Accepted: 12/18/2015] [Indexed: 11/14/2022] Open
Abstract
Penicilliosis caused by the dimorphic fungus Penicillium marneffei is an endemic, AIDS-defining illness and, after tuberculosis and cryptococcosis, the third most common opportunistic infection of AIDS patients in tropical Southeast Asia. Untreated, patients have poor prognosis; however, primary amphotericin B treatment followed by prolonged itraconazole prophylaxis is effective. To identify ATP-binding cassette (ABC) transporters that may play a role in potential multidrug resistance of P. marneffei, we identified and classified all 46 P. marneffei ABC transporters from the genome sequence. PmABC1 and PmABC2 were most similar to the archetype Candida albicans multidrug efflux pump gene CDR1. P. marneffei Abc1p (PmAbc1p) was functionally expressed in Saccharomyces cerevisiae, although at rather low levels, and correctly localized to the plasma membrane, causing cells to be fourfold to eightfold more resistant to azoles and many other xenobiotics than untransformed cells. P. marneffei Abc2p (PmAbc2p) was expressed at similarly low levels, but it had no efflux activity and did not properly localize to the plasma membrane. Interestingly, PmAbc1p mislocalized and lost its transport activity when cells were shifted to 37 °C. We conclude that expression of PmAbc1p in S. cerevisiae confers resistance to several xenobiotics indicating that PmAbc1p may be a multidrug efflux pump.
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Affiliation(s)
| | - Shun Iwatani
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan
| | - Takahiro Oura
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan
| | | | | | - Kyoko Niimi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Masakazu Niimi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Erwin Lamping
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Richard D Cannon
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, New Zealand
| | - Susumu Kajiwara
- Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Japan
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