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Bhagat N, Vakhlu J. Effects of biocontrol Bacillus sp. strain D5 on the pathogenic Fusarium oxysporum R1 at the microscopic and molecular level in Crocus sativus L. (saffron) corm. FEMS MICROBES 2024; 5:xtad025. [PMID: 38250179 PMCID: PMC10799715 DOI: 10.1093/femsmc/xtad025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 11/27/2023] [Accepted: 12/24/2023] [Indexed: 01/23/2024] Open
Abstract
Corm rot of saffron caused by Fusarium oxysporum is a major threat to saffron cultivation the world over. To minimize the ill effects of chemical fungicides, attention has been shifted to the use of biocontrol agents for disease management in a sustainable way. In saffron, various biocontrol agents against corm rot disease have been reported and characterized but no study has been done so far to understand their interaction at the molecular level. The present study was conducted to unravel the mechanism of action of an already characterized native biocontrol agent i.e. Bacillus sp. strain D5 (Bar D5) against F. oxsporum R1 (Fox R1) in the saffron corm. The growth inhibition of Fox R1 was observed in vitro and in planta (saffron corm) by real time imaging. Bacillus sp. strain D5 reduced Fox R1 load in infected corms by 50% as quantified by q-PCR and the colony-forming unit method. Comparative transcriptome analysis revealed upregulation and downregulation of various Fox R1 genes in presence of Bar D5. The genes related to carbon metabolism, cell wall and membrane synthesis, and growth of Fox R1 were significantly downregulated in Bar D5-primed and Fox R1-inoculated corms as compared to only Fox R1-inoculated corms.
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Affiliation(s)
- Nancy Bhagat
- Metagenomics Laboratory, School of Biotechnology, University of Jammu, Jammu, 180006, Jammu and Kashmir, India
| | - Jyoti Vakhlu
- Metagenomics Laboratory, School of Biotechnology, University of Jammu, Jammu, 180006, Jammu and Kashmir, India
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2
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Santos-Lima D, de Castro Spadari C, de Morais Barroso V, Carvalho JCS, de Almeida LC, Alcalde FSC, Ferreira MJP, Sannomiya M, Ishida K. Lipopeptides from an isolate of Bacillus subtilis complex have inhibitory and antibiofilm effects on Fusarium solani. Appl Microbiol Biotechnol 2023; 107:6103-6120. [PMID: 37561179 DOI: 10.1007/s00253-023-12712-z] [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: 05/30/2023] [Revised: 07/10/2023] [Accepted: 07/25/2023] [Indexed: 08/11/2023]
Abstract
Bacillus subtilis species complex is known as lipopeptide-producer with biotechnological potential for pharmaceutical developments. This study aimed to identify lipopeptides from a bacterial isolate and evaluate their antifungal effects. Here, we isolated and identified a lipopeptide-producing bacterium as a species of Bacillus subtilis complex (strain UL-1). Twenty lipopeptides (six iturins, six fengycins, and eight surfactins) were identified in the crude extract (CE) and fractions (F1, F2, F3, and F4), and the highest content of total lipopeptides was observed in CE and F2. The chemical quantification data corroborate with the hemolytic and antifungal activities that CE and F2 were the most hemolytic and inhibited the fungal growth at lower concentrations against Fusarium spp. In addition, they caused morphological changes such as shortening and/or atypical branching of hyphae and induction of chlamydospore-like structure formation, especially in Fusarium solani. CE was the most effective in inhibiting the biofilm formation and in disrupting the mature biofilm of F. solani reducing the total biomass and the metabolic activity at concentrations ≥ 2 µg/mL. Moreover, CE significantly inhibited the adherence of F. solani conidia on contact lenses and nails as well as disrupted the pre-formed biofilms on nails. CE at 100 mg/kg was nontoxic on Galleria mellonella larvae, and it reduced the fungal burden in larvae previously infected by F. solani. Taken together, the lipopeptides obtained from strain UL-1 demonstrated a potent anti-Fusarium effect inducing morphological alterations and antibiofilm activities. Our data open further studies for the biotechnological application of these lipopeptides as potential antifungal agents. KEY POINTS: • Lipopeptides inhibit Fusarium growth and induce chlamydospore-like structures. • Lipopeptides hamper the adherence of conidia and biofilms of Fusarium solani. • Iturins, fengycins, and surfactins were associated with antifungal effects.
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Affiliation(s)
- Daniélle Santos-Lima
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | | | | | | | | | | | | | - Miriam Sannomiya
- School of Arts, Sciences and Humanities, University of São Paulo, Arlindo Béttio St. 1000, São Paulo, SP, 03828-000, Brazil.
| | - Kelly Ishida
- Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, Prof. Lineu Prestes Ave. 1374, São Paulo, SP, 05508-000, Brazil.
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Zhang Y, Wang X, Ran Y, Zhang KQ, Li GH. AfLaeA, a Global Regulator of Mycelial Growth, Chlamydospore Production, Pathogenicity, Secondary Metabolism, and Energy Metabolism in the Nematode-Trapping Fungus Arthrobotrys flagrans. Microbiol Spectr 2023; 11:e0018623. [PMID: 37358432 PMCID: PMC10434191 DOI: 10.1128/spectrum.00186-23] [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: 01/18/2023] [Accepted: 05/15/2023] [Indexed: 06/27/2023] Open
Abstract
Arthrobotrys flagrans (Duddingtonia flagrans) is a typical nematode-trapping fungus which has been used for nematode biocontrol. The global regulator LaeA is widely distributed in filamentous fungi and plays a crucial role in secondary metabolism and development in addition to pathogenicity in fungal pathogens. In this study, the chromosome-level genome of A. flagrans CBS 565.50 was sequenced and homologous sequences of LaeA were identified in A. flagrans. A. flagrans LaeA (AfLaeA) knockout resulted in slower hyphal growth and a smoother hyphal surface. Importantly, deletion of AfLaeA resulted in the absence of chlamydospores and attenuated glycogen and lipid accumulation in hyphae. Similarly, disruption of the AfLaeA gene led to fewer traps and electron-dense bodies, lower protease activity, and a delay in capturing nematodes. The AfLaeA gene had a large effect on the secondary metabolism of A. flagrans, and both the deletion and overexpression of AfLaeA could yield new compounds, whereas some compounds were lost due to the absence of the AfLaeA. Protein-protein interactions between AfLaeA and another eight proteins were detected. Furthermore, transcriptome data analysis showed that 17.77% and 35.51% of the genes were influenced by the AfLaeA gene on days 3 and 7, respectively. AfLaeA gene deletion resulted in the higher expression level of the artA gene cluster, and multiple differentially expressed genes involved in glycogen and lipid synthesis and metabolism showed opposite expression patterns in wild-type and ΔAfLaeA strains. In summary, our results provide novel insights into the functions of AfLaeA in mycelial growth, chlamydospore production, pathogenicity, secondary metabolism, and energy metabolism in A. flagrans. IMPORTANCE The regulation of biological functions, such as the secondary metabolism, development, and pathogenicity of LaeA, has been reported in multiple fungi. But to date, no study on LaeA in nematode-trapping fungi has been reported. Moreover, it has not been investigated whether or not LaeA is involved in energy metabolism and chlamydospore formation has not been investigated. Especially in the formation mechanism of chlamydospores, several transcription factors and signaling pathways are involved in the production of chlamydospores, but the mechanism of chlamydospore formation from an epigenetic perspective has not been revealed. Concurrently, an understanding of protein-protein interactions will provide a broader perspective on the regulatory mechanism of AfLaeA in A. flagrans. This finding is critical for understanding the regulatory role of AfLaeA in the biocontrol fungus A. flagrans and establishes a foundation for developing high-efficiency nematode biocontrol agents.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Xin Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Yuan Ran
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
| | - Guo-Hong Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Sciences, Yunnan University, Kunming, China
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Fernandes LB, D'Souza JS, Prasad TSK, Ghag SB. Isolation and characterization of extracellular vesicles from Fusarium oxysporum f. sp. cubense, a banana wilt pathogen. Biochim Biophys Acta Gen Subj 2023; 1867:130382. [PMID: 37207907 DOI: 10.1016/j.bbagen.2023.130382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 05/08/2023] [Accepted: 05/15/2023] [Indexed: 05/21/2023]
Abstract
Fusarium wilt of banana is a destructive widespread disease caused by Fusarium oxysporum f. sp. cubense (Foc) that ravaged banana plantations globally, incurring huge economic losses. Current knowledge demonstrates the involvement of several transcription factors, effector proteins, and small RNAs in the Foc-banana interaction. However, the precise mode of communication at the interface remains elusive. Cutting-edge research has emphasized the significance of extracellular vesicles (EVs) in trafficking the virulent factors modulating the host physiology and defence system. EVs are ubiquitous inter- and intra-cellular communicators across kingdoms. This study focuses on the isolation and characterization of Foc EVs from methods that make use of sodium acetate, polyethylene glycol, ethyl acetate, and high-speed centrifugation. Isolated EVs were microscopically visualized using Nile red staining. Further, the EVs were characterized using transmission electron microscopy, which revealed the presence of spherical, double-membrane, vesicular structures ranging in size from 50 to 200 nm (diameter). The size was also determined using the principle based on Dynamic Light Scattering. The Foc EVs contained proteins that were separated using SDS-PAGE and ranged between 10 and 315 kDa. Mass spectrometry analysis revealed the presence of EV-specific marker proteins, toxic peptides, and effectors. The Foc EVs were found to be cytotoxic, whose toxicity increased with EVs isolated from the co-culture preparation. Taken together, a better understanding of Foc EVs and their cargo will aid in deciphering the molecular crosstalk between banana and Foc.
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Affiliation(s)
- Lizelle B Fernandes
- School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai campus, Kalina, Santacruz (East), Mumbai 400098, India
| | - Jacinta S D'Souza
- School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai campus, Kalina, Santacruz (East), Mumbai 400098, India
| | - T S Keshava Prasad
- Center for Systems Biology and Molecular Medicine, Yenepoya Research Center, Yenepoya (Deemed to be University), University Road, Deralakatte, Mangalore 575018, India
| | - Siddhesh B Ghag
- School of Biological Sciences, UM-DAE Centre for Excellence in Basic Sciences, University of Mumbai campus, Kalina, Santacruz (East), Mumbai 400098, India.
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5
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Tahmasebi A, Asgari A, Bakhshi S, Ghaffar Shahriari A, Won Lee C. Ultrasound application for the decontamination of roselle (Hibiscus sabdariffa L.) seeds: Influence on fungal inhibition and seed quality. ULTRASONICS SONOCHEMISTRY 2023; 95:106404. [PMID: 37060710 PMCID: PMC10130695 DOI: 10.1016/j.ultsonch.2023.106404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/20/2023] [Accepted: 04/08/2023] [Indexed: 06/19/2023]
Abstract
Seed decay is a major problem caused by pathogens that adversely affect seed yield and quality in agricultural production. Herein, the effect of 28 KHz ultrasound treatment for 20, 40 and 60 min and 1.5% sodium hypochlorite solution for 20 min was assessed for the decontamination of roselle (Hibiscus sabdariffa L.) seeds. In addition, seed germination indices, seedling growth traits, total phenolic content and the activity of defense-related enzymes, viz. peroxidase, superoxide dismutase, catalase and malondialdehyde were measured in the treated seeds. An isolate of Fusarium solani was obtained from roselle seeds and identified as the causal agent of roselle seed rot based on morphological and molecular characteristics. After six days of seed storage, the microbial infection caused the highest seed rot in the control seeds on the average of 56.67%, whereas ultrasound treatment for 60 min could remarkably reduce the seed decay by 3.33%. At the end of seed storage, the fungal load showed the highest (7.72 Log CFU ml-1) and lowest (6.99 Log CFU ml-1) rates in the control and ultrasound treatment for 60 min, respectively. Total phenolic content was significantly increased in ultrasound treatment for 60 min compared to control and sodium hypochlorite treatments. Moreover, the activity of peroxidase, superoxide dismutase and catalase was noticeably improved in ultrasound treatment for 60 min. Furthermore, ultrasound treatment did not show any adverse effects on seed germination indices and seedling growth traits of the roselle plants. Overall, ultrasound treatment for 60 min could effectively decrease roselle seed decay and the fungal load without changing seed and seedling quality.
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Affiliation(s)
- Aminallah Tahmasebi
- Department of Agriculture, Minab Higher Education Center, University of Hormozgan, Bandar Abbas, Iran; Plant Protection Research Group, University of Hormozgan, Bandar Abbas, Iran.
| | - Ashkan Asgari
- Department of Agriculture, Minab Higher Education Center, University of Hormozgan, Bandar Abbas, Iran; Research Group of Agroecology in Dryland Areas, University of Hormozgan, Bandar Abbas, Iran
| | - Somayeh Bakhshi
- Department of Plant Protection, College of Agriculture, Shiraz University, Shiraz, Iran
| | - Amir Ghaffar Shahriari
- Department of Agriculture and Natural Resources, Higher Education Center of Eghlid, Eghlid, Iran
| | - Chul Won Lee
- Department of Chemistry, Chonnam National University, Gwangju, Republic of Korea.
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6
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Pazarlar S, Madriz-Ordeñana K, Thordal-Christensen H. Bacillus cereus EC9 protects tomato against Fusarium wilt through JA/ET-activated immunity. FRONTIERS IN PLANT SCIENCE 2022; 13:1090947. [PMID: 36589090 PMCID: PMC9798288 DOI: 10.3389/fpls.2022.1090947] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
The mechanisms of action and the limitations of effectiveness of natural biocontrol agents should be determined in order to convert them into end products that can be used in practice. Rhizosphere Bacillus spp. protect plants from various pathogens by displaying several modes of action. However, the ability of Bacillus spp. to control plant diseases depends on the interaction between the bacteria, host, and pathogen, and the environmental conditions. We found that soil drenching of tomato plants with the non-antifungal Bacillus cereus strain EC9 (EC9) enhances plant defense against Fusarium oxysporum f. sp. lycopersici (Fol). To study the involvement of plant defense-related phytohormones in the regulation of EC9-activated protection against Fol, we conducted plant bioassays in tomato genotypes impaired in salicylic acid (SA) accumulation, jasmonic acid (JA) biosynthesis, and ethylene (ET) production, and analyzed the transcript levels of pathways-related marker genes. Our results indicate that JA/ET-dependent signaling is required for EC9-mediated protection against Fol in tomato. We provide evidence that EC9 primes tomato plants for enhanced expression of proteinase inhibitor I (PI-I) and ethylene receptor4 (ETR4). Moreover, we demonstrated that EC9 induces callose deposition in tomato roots. Understanding the involvement of defense-related phytohormones in EC9-mediated defense against Fusarium wilt has increased our knowledge of interactions between non-antifungal plant defense-inducing rhizobacteria and plants.
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Affiliation(s)
- Sercan Pazarlar
- Department of Plant Protection, Faculty of Agriculture, Ege University, Izmir, Turkey
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
| | - Kenneth Madriz-Ordeñana
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
| | - Hans Thordal-Christensen
- Department of Plant and Environmental Sciences, Section for Plant and Soil Science, University of Copenhagen, Copenhagen, Denmark
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7
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Sasaki K, Ito Y, Hamada Y, Dowaki A, Jogaiah S, Ito SI. FoMC69 Gene in Fusarium oxysporum f. sp. radicis-lycopersici Is Essential for Pathogenicity by Involving Normal Function of Chlamydospores. Pathogens 2022; 11:pathogens11121433. [PMID: 36558767 PMCID: PMC9784146 DOI: 10.3390/pathogens11121433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/22/2022] [Accepted: 11/26/2022] [Indexed: 11/30/2022] Open
Abstract
Fusarium oxysporum f. sp. radicis-lycopersici (Forl) causes crown and root rot disease in tomato, effecting severe economic losses. However, research on the pathogenicity genes and infection strategy of Forl is limited compared to that on F. oxysporum f. sp. lycopersici (Fol). In this study, we characterized FoMC69 gene in Forl as a homolog of MC69 required for pathogenicity in rice blast pathogen-Magnaporthe oryzae. Gene expression analysis revealed that FoMC69 expressionin Forl is higher than that in Folin planta. FoMC69-knockout mutant of Forl had significantly reduced root rot symptoms compared to the wild-type strain, and full pathogenicity was restored by complementation. By contrast, ΔFoMC69 mutant of Fol presented the same symptoms as the wild type, suggesting that FoMC69 of Forl, but not of Fol, was essential for full virulence in tomato plants. Morphological differences between the Forl and ΔFoMC69 in the roots were observed by fluorescent labeling using WGA-FITC. Chlamydospores of the ΔFoMC69 mutant of Forlcontinuously increased during infection and were three times higher than that of the wild type at 21 days post-inoculation. These observations suggest that FoMC69 of Forl is required for virulence to tomato plants by involving the normal development and germination of chlamydospores.
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Affiliation(s)
- Kazunori Sasaki
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
- Research Center for Thermotolerant Microbial Resources (RCTMR), Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Yumi Ito
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Yuki Hamada
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Ayano Dowaki
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
| | - Sudisha Jogaiah
- Laboratory of Plant Healthcare and Diagnostics, PG Department of Biotechnology and Microbiology, Karnataka University, Dharwad 580003, India
- Department of Environmental Science, Central University of Kerala, Tejaswini Hills, Kasaragod 671316, India
| | - Shin-ichi Ito
- Department of Biological and Environmental Sciences, Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi 753-8515, Japan
- Research Center for Thermotolerant Microbial Resources (RCTMR), Yamaguchi University, Yamaguchi 753-8515, Japan
- Correspondence:
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Yu M, Yu J, Cao H, Pan X, Song T, Qi Z, Du Y, Huang S, Liu Y. The Velvet Protein UvVEA Regulates Conidiation and Chlamydospore Formation in Ustilaginoidea virens. J Fungi (Basel) 2022; 8:jof8050479. [PMID: 35628735 PMCID: PMC9148152 DOI: 10.3390/jof8050479] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/30/2022] [Accepted: 05/02/2022] [Indexed: 02/01/2023] Open
Abstract
Rice false smut, caused by Ustilaginoidea virens, is a serious disease of rice worldwide, severely reducing the quantity and quality of rice production. The conserved fungal velvet proteins are global regulators of diverse cellular processes. We identified and functionally characterized two velvet genes, UvVEA and UvVELB, in U. virens. The deletion of these genes affected the conidiation of U. virens but had no effect on the virulence of this pathogen. Interestingly, the ΔUvVEA mutants appeared in the form of smaller false smut balls with a reduced number of chlamydospores compared with the wide-type strains. In addition, the deletion of UvVEA affected the expression of some transmembrane transport genes during chlamydospore formation and rice false smut balls development. Furthermore, the ΔUvVEA mutants were shown to be defective in the utilization of glucose. These findings proved the regulatory mechanism underlying the formation of rice false smut balls and chlamydospores and provided a basis for the further exploration of the mechanism of these processes.
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Affiliation(s)
- Mina Yu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 311400, China; (M.Y.); (S.H.)
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Junjie Yu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Huijuan Cao
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Xiayan Pan
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Tianqiao Song
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Zhongqiang Qi
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Yan Du
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
| | - Shiwen Huang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 311400, China; (M.Y.); (S.H.)
| | - Yongfeng Liu
- Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; (J.Y.); (H.C.); (X.P.); (T.S.); (Z.Q.); (Y.D.)
- Correspondence: ; Tel.: +86-25-8439-1002
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9
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Kurian SM, Lichius A, Read ND. Ca2+ Signalling Differentially Regulates Germ-Tube Formation and Cell Fusion in Fusarium oxysporum. J Fungi (Basel) 2022; 8:jof8010090. [PMID: 35050029 PMCID: PMC8780837 DOI: 10.3390/jof8010090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 11/16/2022] Open
Abstract
Fusarium oxysporum is an important plant pathogen and an emerging opportunistic human pathogen. Germination of conidial spores and their fusion via conidial anastomosis tubes (CATs) are significant events during colony establishment in culture and on host plants and, hence, very likely on human epithelia. CAT fusion exhibited by conidial germlings of Fusarium species has been postulated to facilitate mitotic recombination, leading to heterokaryon formation and strains with varied genotypes and potentially increased virulence. Ca2+ signalling is key to many of the important physiological processes in filamentous fungi. Here, we tested pharmacological agents with defined modes of action in modulation of the mammalian Ca2+ signalling machinery for their effect on germination and CAT-mediated cell fusion in F. oxysporum. We found various drug-specific and dose-dependent effects. Inhibition of calcineurin by FK506 or cyclosporin A, as well as chelation of extracellular Ca2+ by BAPTA, exclusively inhibit CAT induction but not germ-tube formation. On the other hand, inhibition of Ca2+ channels by verapamil, calmodulin inhibition by calmidazolium, and inhibition of mitochondrial calcium uniporters by RU360 inhibited both CAT induction and germ-tube formation. Thapsigargin, an inhibitor of mammalian sarco/endoplasmic reticulum Ca2+ ATPase (SERCA), partially inhibited CAT induction but had no effect on germ-tube formation. These results provide initial evidence for morphologically defining roles of Ca2+-signalling components in the early developmental stages of F. oxysporum colony establishment—most notably, the indication that calcium ions act as self-signalling molecules in this process. Our findings contribute an important first step towards the identification of Ca2+ inhibitors with fungas-specific effects that could be exploited for the treatment of infected plants and humans.
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Affiliation(s)
- Smija M. Kurian
- Manchester Fungal Infection Group, University of Manchester, Manchester M13 9NT, UK;
- College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
- Correspondence:
| | - Alexander Lichius
- Department of Microbiology, University of Innsbruck, 6020 Innsbruck, Austria;
| | - Nick D. Read
- Manchester Fungal Infection Group, University of Manchester, Manchester M13 9NT, UK;
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10
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Wang CW, Yu YH, Wu CY, Feng RY, Tandon K, Chen YL, Tang SL. Detection of Pathogenic and Beneficial Microbes for Roselle Wilt Disease. Front Microbiol 2021; 12:756100. [PMID: 34790182 PMCID: PMC8591290 DOI: 10.3389/fmicb.2021.756100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 10/11/2021] [Indexed: 11/18/2022] Open
Abstract
Wilt disease of roselle (Hibiscus sabdariffa L.) is common in Taiwan; however, the causative agent remains unknown. The stems of wilted roselle are browned, slightly constricted, and covered by white aerial hyphae, suggesting that potential pathogens may originate from soil. To identify the potential pathogens, we conducted a rhizosphere microbiota survey in phenotypically healthy and diseased plants through fungal internal transcribed spacer (ITS) and bacterial 16S rRNA amplicon sequencing for uncovering the microbial compositions in the roselle rhizosphere. The fungal family Nectriaceae exhibited significantly higher abundance in diseased rhizospheres than in healthy rhizospheres, and this bacterial community was more specific to geography (i.e., plot-dependent) than to rhizosphere disease status. However, a few bacterial groups such as Bacilli were associated with the healthy rhizosphere. Fusarium species were the most dominant species of Nectriaceae in the survey and became the main target for potential pathogen isolation. We successfully isolated 119 strains from diseased plants in roselle fields. Koch’s postulates were used to evaluate the pathogenicity of these strains; our results indicated that Fusarium solani K1 (FsK1) can cause wilting and a rotted pith in roselles, which was consistent with observations in the fields. This is the first demonstration that F. solani can cause roselle wilt in Taiwan. Furthermore, these newly isolated strains are the most dominant operational taxonomic units detected in ITS amplicon sequencing in diseased rhizospheres, which serves as further evidence that F. solani is the main pathogen causing the roselle wilt disease. Administration of Bacillus velezensis SOI-3374, a strain isolated from a healthy roselle rhizosphere, caused considerable anti-FsK1 activity, and it can serve as a potential biocontrol agent against roselle wilt disease.
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Affiliation(s)
- Chih-Wei Wang
- Taitung District Agricultural Research and Extension Station, Council of Agriculture, Executive Yuan, Taitung, Taiwan.,Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.,Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.,Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Yu-Hsiang Yu
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan
| | - Chun-Yao Wu
- Taitung District Agricultural Research and Extension Station, Council of Agriculture, Executive Yuan, Taitung, Taiwan
| | - Ru-Ying Feng
- Master Program for Plant Medicine, National Taiwan University, Taipei, Taiwan
| | - Kshitij Tandon
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Ying-Lien Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, Taiwan.,Master Program for Plant Medicine, National Taiwan University, Taipei, Taiwan
| | - Sen-Lin Tang
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan.,Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.,Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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