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Fan Y, He X, Dai J, Yang N, Jiang Q, Xu Z, Tang X, Yu Y, Xiao M. Induced Resistance Mechanism of Bacillus velezensis S3-1 Against Pepper Wilt. Curr Microbiol 2023; 80:367. [PMID: 37819393 DOI: 10.1007/s00284-023-03470-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 09/02/2023] [Indexed: 10/13/2023]
Abstract
In recent years, pepper wilt has emerged as a pivotal constraint on pepper yield augmentation. Bacillus velezensis S3-1, with a wide array of hosts, can be used as both a biocontrol agent and biofertilizer. Nonetheless, the precise mechanisms underpinning its employment in combating pepper wilt remain cloaked in ambiguity. In our study, we found that B. velezensis S3-1 could significantly inhibit Fusarium sp. F1T that caused pepper wilt. S3-1 could effectively inhibit both the growth and germination of F1T conidia, leading to a reduction in the spore germination percentage from 83.2 to 37.1% in vitro experiments. Additionally, leaf detachment experiments revealed that the volatile compounds produced by S3-1 could inhibit the spread of pepper leaf spot area. Moreover, we observed a significant decrease in the content of malondialdehyde (MDA) in pepper treated with S3-1, along with a significant increase in the content of soluble protein, polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonia-lyase (PAL) in pepper. Furthermore, RT-PCR analysis showed that the expression of the defense genes CaPR 1 and CaPIN II in pepper after treatment with S3-1 was significantly upregulated, suggesting that S3-1 had the potential to induce systemic resistance in pepper, thereby enhancing its disease resistance. Hence, our findings suggest that S3-1 can be a promising biocontrol agent for managing pepper wilt in modern agriculture.
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Affiliation(s)
- Yongjie Fan
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Xingjie He
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Jiawei Dai
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Ning Yang
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Qiuyan Jiang
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Zhaofeng Xu
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Xiaorong Tang
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Yating Yu
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China
| | - Ming Xiao
- College of Life Sciences, Shanghai Normal University, Shanghai, 200234, People's Republic of China.
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Tsunoda T, Asamizu S, Mahmud T. Biochemical Characterization of GacI, a Bifunctional Glycosyltransferase-Phosphatase Enzyme Involved in Acarbose Biosynthesis in Streptomyces glaucescens GLA.O. Biochemistry 2022; 61:2628-2635. [PMID: 36288494 PMCID: PMC9669214 DOI: 10.1021/acs.biochem.2c00473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Acarbose, a pseudotetrasaccharide produced by several strains of Actinoplanes and Streptomyces, is an α-glucosidase inhibitor clinically used to control type II diabetes. Bioinformatic analysis of the biosynthetic gene clusters of acarbose in Actinoplanes sp. SE50/110 (the acb cluster) and Streptomyces glaucescens GLA.O (the gac cluster) revealed their distinct genetic organizations and presumably biosynthetic pathways. However, to date, only the acarbose pathway in the SE50/110 strain has been extensively studied. Here, we report that GacI, one of the proteins that appear to be different between the two pathways, is a bifunctional glycosyltransferase family 5 (GT5)-phosphatase (PP) enzyme that functions at two different steps in acarbose biosynthesis in S. glaucescens GLA.O. In the acb pathway, the GT and the PP reactions are performed by two different enzymes. Truncated GacI proteins having only the GT or the PP domain showed comparable catalytic activity with the full-length GacI, indicating that domain separation does not significantly affect their respective catalytic activity. GacI, which is widely distributed in many Streptomyces, represents the first example of naturally occurring GT5-PP bifunctional enzymes biochemically characterized.
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Affiliation(s)
- Takeshi Tsunoda
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Shumpei Asamizu
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
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Grisnik M, Grinath JB, Munafo JP, Walker DM. Functional Redundancy in Bat Microbial Assemblage in the Presence of the White Nose Pathogen. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02098-2. [PMID: 35953677 DOI: 10.1007/s00248-022-02098-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Understanding how host-associated microbial assemblages respond to pathogen invasion has implications for host health. Until recently, most investigations have focused on understanding the taxonomic composition of these assemblages. However, recent studies have suggested that microbial assemblage taxonomic composition is decoupled from its function, with assemblages being taxonomically varied but functionally constrained. The objective of this investigation was to understand how the Tri-colored bat, Perimyotis subflavus cutaneous microbial assemblage responds to fungal pathogen invasion within a functional context. We hypothesized that at a broad scale (e.g., KEGG pathways), there will be no difference in the functional assemblages between the white nose pathogen, Pseudogymnoascus destructans, positive and negative bats; and this pattern will be driven by the functional redundancy of bacterial taxa. At finer scales (e.g., gene models), we postulate differences in function attributed to interactions between bacteria and P. destructans, resulting in the production of antifungal metabolites. To test this, we used a combination of shotgun metagenomic and amplicon sequencing to characterize the bat cutaneous microbial assemblage in the presence/absence of P. destructans. Results showed that while there was a shift in taxonomic assemblage composition between P. destructans positive and negative bats, there was little overall difference in microbial function. Functional redundancy across bacterial taxa was clear at a broad-scale; however, both redundancy and variation in bacterial capability related to defense against pathogens was evident at finer scales. While functionality of the microbial assemblage was largely conserved in relation to P. destructans, the roles of particular functional pathways in resistance to fungal pathogens require further attention.
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Affiliation(s)
- Matthew Grisnik
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
| | - Joshua B Grinath
- Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209, USA
| | - John P Munafo
- Department of Food Science, University of Tennessee Knoxville, Knoxville, TN, 37996, USA
| | - Donald M Walker
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA
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Ren L, Hou YP, Zhu YY, Zhao FF, Duan YB, Wu LY, Duan XX, Zhang J, Zhou MG. Validamycin A Enhances the Interaction Between Neutral Trehalase and 14-3-3 Protein Bmh1 in Fusarium graminearum. PHYTOPATHOLOGY 2022; 112:290-298. [PMID: 34156266 DOI: 10.1094/phyto-05-21-0214-r] [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] [Indexed: 06/13/2023]
Abstract
In agriculture, Trehalase is considered the main target of the biological fungicide validamycin A, and the toxicology mechanism of validamycin A is unknown. 14-3-3 proteins, highly conserved proteins, participate in diverse cellular processes, including enzyme activation, protein localization, and acting as a molecular chaperone. In Saccharomyces cerevisiae, the 14-3-3 protein Bmh1could interact with Nth1 to respond to specific external stimuli. Here, we characterized FgNth, FgBmh1, and FgBmh2 in Fusarium graminearum. ΔFgNth, ΔFgBmh1, and ΔFgBmh2 displayed great growth defects and their peripheral tips hyphae generated more branches when compared with wild-type (WT) PH-1. When exposed to validamycin A as well as high osmotic and high temperature stresses, ΔFgNth, ΔFgBmh1, and ΔFgBmh2 showed more tolerance than WT. Both ΔFgNth and ΔFgBmh1 displayed reduced deoxynivalenol production but opposite for ΔFgBmh2, and all three deletion mutants showed reduced virulence on wheat coleoptiles. In addition, coimmunoprecipitation (Co-IP) experiments suggested that FgBmh1 and FgBmh2 both interact with FgNth, but no interaction was detected between FgBmh1 and FgBmh2 in our experiments. Further, validamycin A enhances the interaction between FgBmh1 and FgNth in a positive correlation under concentrations of 1 to 100 μg/ml. In addition, both high osmotic and high temperature stresses promote the interaction between FgBmh1 and FgNth. Co-IP assay also showed that neither FgBmh1 nor FgBmh2 could interact with FgPbs2, a MAPKK kinase in the high-osmolarity glycerol pathway. However, FgBmh2 but not FgBmh1 binds to the heat shock protein FgHsp70 in F. graminearum. Taken together, our results demonstrate that FgNth and FgBmh proteins are involved in growth and responses to external stresses and virulence; and validamycin enhanced the interaction between FgNth and FgBmh1in F. graminearum.
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Affiliation(s)
- Li Ren
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Yi-Ping Hou
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Yuan-Ye Zhu
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Fei-Fei Zhao
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Ya-Bing Duan
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Luo-Yu Wu
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Xiao-Xin Duan
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Jie Zhang
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
| | - Ming-Guo Zhou
- College of Plant Protection and The Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095 China
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Kalampokis IF, Erban A, Amillis S, Diallinas G, Kopka J, Aliferis KA. Untargeted metabolomics as a hypothesis-generation tool in plant protection product discovery: Highlighting the potential of trehalose and glycerol metabolism of fungal conidiospores as novel targets. Metabolomics 2020; 16:79. [PMID: 32601735 DOI: 10.1007/s11306-020-01699-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/15/2020] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The production of high quality and safe food represents a main priority for the agri-food sector in the effort to sustain the exponentially growing human population. Nonetheless, there are major challenges that require the discovery of new, alternative, and improved plant protection products (PPPs). Focusing on fungal plant pathogens, the dissection of mechanisms that are essential for their survival provides insights that could be exploited towards the achievement of the aforementioned aim. In this context, the germination of fungal spores, which are essential structures for their dispersal, survival, and pathogenesis, represents a target of high potential for PPPs. To the best of our knowledge, no PPPs that target the germination of fungal spores currently exist. OBJECTIVES Within this context, we have mined for changes in the metabolite profiles of the model fungus Aspergillus nidulans FGSC A4 conidiospores during germination, in an effort to discover key metabolites and reactions that could potentially become targets of PPPs. METHODS Untargeted GC/EI-TOF/MS metabolomics and multivariate analyses were employed to monitor time-resolved changes in the metabolomes of germinating A. nidulans conidiospores. RESULTS Analyses revealed that trehalose hydrolysis plays a pivotal role in conidiospore germination and highlighted the osmoregulating role of the sugar alcohols, glycerol, and mannitol. CONCLUSION The ineffectiveness to introduce active ingredients that exhibit new mode(s)-of-action as fungicides, dictates the urge for the discovery of PPPs, which could be exploited to combat major plant protection issues. Based on the crucial role of trehalose hydrolysis in conidiospore dormancy breakage, and the subsequent involvement of glycerol in their germination, it is plausible to suggest their biosynthesis pathways as potential novel targets for the next-generation antifungal PPPs. Our study confirmed the applicability of untargeted metabolomics as a hypothesis-generation tool in PPPs' research and discovery.
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Affiliation(s)
- Ioannis F Kalampokis
- Laboratory of Pesticide Science, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Alexander Erban
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Sotirios Amillis
- Department of Biology, National and Kapodistrian University of Athens, 15784, Panepistimioupolis, Athens, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, 15784, Panepistimioupolis, Athens, Greece
| | - Joachim Kopka
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Konstantinos A Aliferis
- Laboratory of Pesticide Science, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
- Department of Plant Science, McGill University, 21111 Lakeshore Road, Montréal, H9X 3V9, Canada.
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The Inhibitory Effect of Validamycin A on Aspergillus flavus. Int J Microbiol 2020; 2020:3972415. [PMID: 32676114 PMCID: PMC7336217 DOI: 10.1155/2020/3972415] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/08/2020] [Accepted: 06/03/2020] [Indexed: 12/13/2022] Open
Abstract
Aspergillus flavus is one of the most common isolates from patients with fungal infections. Aspergillus infection is usually treated with antifungal agents, but side effects of these agents are common. Trehalase is an essential enzyme involved in fungal metabolism, and the trehalase inhibitor, validamycin A, has been used to prevent fungal infections in agricultural products. In this study, we observed that validamycin A significantly increased trehalose levels in A. flavus conidia and delayed germination, including decreased fungal adherence. In addition, validamycin A and amphotericin B showed a combinatorial effect on A. flavus ATCC204304 and clinical isolates with high minimum inhibitory concentrations (MICs) of amphotericin B using checkerboard assays. We observed that validamycin A and amphotericin B had a synergistic effect on A. flavus strains resistant to amphotericin B. The MICs in the combination of validamycin A and amphotericin B were at 0.125 μg/mL and 2 μg/mL, respectively. The FICI of validamycin A and amphotericin B of these clinical isolates was about 0.25-0.28 with synergistic effects. No drug cytotoxicity was observed in human bronchial epithelial cells treated with validamycin A using LDH-cytotoxicity assays. In conclusion, this study demonstrated that validamycin A inhibited the growth of A. flavus and delayed conidial germination. Furthermore, the combined effect of validamycin A with amphotericin B increased A. flavus killing, without significant cytotoxicity to human bronchial epithelial cells. We propose that validamycin A could potentially be used in vivo as an alternative treatment for A. flavus infections.
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Toxicity and Characteristics of Antifungal Substances Produced by Bacillus amyloliquefaciens IUB158-03. ACTA ACUST UNITED AC 2009. [DOI: 10.5352/jls.2009.19.11.1672] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Minagawa K, Zhang Y, Ito T, Bai L, Deng Z, Mahmud T. ValC, a new type of C7-Cyclitol kinase involved in the biosynthesis of the antifungal agent validamycin A. Chembiochem 2007; 8:632-41. [PMID: 17335096 PMCID: PMC3136165 DOI: 10.1002/cbic.200600528] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The gene valC, which encodes an enzyme homologous to the 2-epi-5-epi-valiolone kinase (AcbM) of the acarbose biosynthetic pathway, was identified in the validamycin A biosynthetic gene cluster. Inactivation of valC resulted in mutants that lack the ability to produce validamycin A. Complementation experiments with a replicating plasmid harboring full-length valC restored the production of validamycin A, thus suggesting a critical function of valC in validamycin biosynthesis. In vitro characterization of ValC revealed a new type of C7-cyclitol kinase, which phosphorylates valienone and validone--but not 2-epi-5-epi-valiolone, 5-epi-valiolone, or glucose--to afford their 7-phosphate derivatives. The results provide new insights into the activity of this enzyme and also confirm the existence of two different pathways leading to the same end-product: the valienamine moiety common to acarbose and validamycin A.
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Affiliation(s)
- Kazuyuki Minagawa
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Yirong Zhang
- Laboratory of Microbial Metabolism and School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai 200030, China
| | - Takuya Ito
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
| | - Linquan Bai
- Laboratory of Microbial Metabolism and School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai 200030, China
- Fax: 86-21-62932418,
| | - Zixin Deng
- Laboratory of Microbial Metabolism and School of Life Science & Biotechnology, Shanghai Jiaotong University, Shanghai 200030, China
| | - Taifo Mahmud
- Department of Pharmaceutical Sciences, Oregon State University, Corvallis, OR 97331-3507 (USA)
- Fax: 1-541-737-3999,
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