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Lin Y, Wang J, Yang K, Fan L, Wang Z, Yin Y. Regulation of conidiation, polarity growth, and pathogenicity by MrSte12 transcription factor in entomopathogenic fungus, Metarhizium rileyi. Fungal Genet Biol 2021; 155:103612. [PMID: 34303798 DOI: 10.1016/j.fgb.2021.103612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/14/2021] [Accepted: 07/14/2021] [Indexed: 11/17/2022]
Abstract
Metarhizium rileyi, a well-known filamentous biocontrol fungus, is the main pathogen of numerous field pests, especially noctuid pests. To explore the potential factors involved in the fungal pathogenicity, MrSte12, an important and conserved functional transcription factor in mitogen-activated protein kinase pathway was carried out by functional analysis. Homologous recombination was used to disrupt the MrSte12 gene in M. rileyi. The deletant fungal strain exhibited malformed hyphae and impaired conidiogenesis, and conidia could not be collected from △MrSte12 in vitro towards SMAY medium. Although conidia could be collected again supplemented with KCl within SMAY medium, the conidial germination, growth and stress tolerance were much weaker compared with that in WT. Additionally, △MrSte12 showed a dramatic reduction in virulence in intra-hemolymph injections and no pathogenicity in topical inoculations against noctuid pests, which is due to the failure of appressorium formation. Moreover, the content of chitin and β-1, 3-glucan in cell wall significantly reduced in mutant conidia. These results indicate that the MrSte12 gene markedly contributes to invasive growth and conidiation, as well as the major pathogenicity in M. rileyi.
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Affiliation(s)
- Yunlong Lin
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing 400030, People's Republic of China
| | - Jing Wang
- Instituty of Tobacco Scientific and Technology of Chongqing, Chongqing, China
| | - Kai Yang
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing 400030, People's Republic of China
| | - Liqin Fan
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing 400030, People's Republic of China
| | - Zhongkang Wang
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing 400030, People's Republic of China.
| | - Youping Yin
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing 400030, People's Republic of China.
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Wu J, Yu X, Wang X, Tang L, Ali S. Matrine Enhances the Pathogenicity of Beauveria brongniartii Against Spodoptera litura (Lepidoptera: Noctuidae). Front Microbiol 2019; 10:1812. [PMID: 31456766 PMCID: PMC6700297 DOI: 10.3389/fmicb.2019.01812] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 07/23/2019] [Indexed: 02/02/2023] Open
Abstract
The repetitive application of pesticides at high doses against Spodoptera litura Fabricius has resulted in development of pesticide resistance and harmful effects to the natural environmental. Hence, finding alternate pest control strategies, such as entomopathogenic fungi or their application in combination with other natural chemicals, is of great importance to solve the abovementioned problems. This study presents the toxic effects of Beauveria brongniartii and matrine (individual or in combination with each other) against tobacco cutworm (S. litura). Different matrine treatments caused a dose dependent increase in S. litura mortality at different time intervals. The biological parameters of B. brongniartii (germination rate and average daily mycelia growth) were not inhibited by different matrine treatments. Different conidial concentrations of B. brongniartii caused significantly different mortalities of 2nd instar S. litura larvae at different time intervals. Different combined treatments of B. brongniartii and matrine showed a significant synergistic effect against S. litura under laboratory and semi-field conditions. The current findings showed a strong synergistic action for combined application of B. brongniartii and matrine against S. litura. Our results will provide baseline information on combined application of entomopathogenic fungi and natural chemicals in integrated pest management programs against S. litura.
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Affiliation(s)
- Jianhui Wu
- Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, China
| | - Xintong Yu
- Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, China
| | - Xiaoshuang Wang
- Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, China
| | - Liangde Tang
- Key Laboratory of Integrated Pest Management on Tropical Crops, Ministry of Agriculture, Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Shaukat Ali
- Key Laboratory of Bio-Pesticide Innovation and Application, Engineering Research Centre of Biological Control, South China Agricultural University, Guangzhou, China
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Freimoser FM, Grundschober A, Aebi M, Tuor U. In vitro cultivation of the entomopathogenic fungusEntomophthora thripidum: isolation, growth requirements, and sporulation. Mycologia 2019. [DOI: 10.1080/00275514.2000.12061146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Florian M. Freimoser
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Anne Grundschober
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Markus Aebi
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
| | - Urs Tuor
- Eidgenössische Technische Hochschule ETH, Mikrobiologisches Institut, Schmelzbergstr. 7, CH-8092 Zürich, Switzerland
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Molecular Genetics of Beauveria bassiana Infection of Insects. ADVANCES IN GENETICS 2016; 94:165-249. [DOI: 10.1016/bs.adgen.2015.11.003] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Liu H, Zhao X, Guo M, Liu H, Zheng Z. Growth and metabolism of Beauveria bassiana spores and mycelia. BMC Microbiol 2015; 15:267. [PMID: 26581712 PMCID: PMC4652391 DOI: 10.1186/s12866-015-0592-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 10/28/2015] [Indexed: 11/19/2022] Open
Abstract
Background Fungi are ubiquitous in nature and have evolved over time to colonize a wide range of ecosystems including pest control. To date, most research has focused on the hypocrealean genera Beauveria bassiana, which is a typical filamentous fungus with a high potential for insect control. The morphology and components of fungi are important during the spores germination and outgrow to mycelia. However, to the best of our knowledge, there is no report on the morphology and components of B. bassiana spores and mycelia. In the work, the growth and metabolism of Beauveria bassiana spores and mycelia were studied. High performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to study the metabolism of B. bassiana spores and mycelia. Principal component analysis (PCA) based on HPLC-MS was conducted to study the different components of the spores and mycelia of the fungus. Metabolic network was established based on HPLC-MS and KEGG database. Results Through Gompertz model based on macroscopic and microscopic techniques, spore elongation length was found to increase exponentially until approximately 23.1 h after cultivation, and then growth became linear. In the metabolic network, the decrease of glyoxylate, pyruvate, fumarate, alanine, succinate, oxaloacetate, dihydrothymine, ribulose, acetylcarnitine, fructose-1, 6-bisphosphate, mycosporin glutamicol, and the increase of betaine, carnitine, ergothioneine, sphingosine, dimethyl guanosine, glycerophospholipids, and in spores indicated that the change of the metabolin can keep spores in inactive conditions, protect spores against harmful effects and survive longer. Conclusions Analysis of the metabolic pathway in which these components participate can reveal the metabolic difference between spores and mycelia, which provide the tools for understand and control the process of of spores germination and outgrow to mycelia.
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Affiliation(s)
- Hongxia Liu
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Xusheng Zhao
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Mingxin Guo
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Hui Liu
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui, 230031, P. R. China.
| | - Zhiming Zheng
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui, 230031, P. R. China.
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Liu H, Zhao X, Guo M, Liu H, Zheng Z. Growth and metabolism of Beauveria bassiana spores and mycelia. BMC Microbiol 2015. [PMID: 26581712 DOI: 10.1186/s12866-015-0592-594?] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND Fungi are ubiquitous in nature and have evolved over time to colonize a wide range of ecosystems including pest control. To date, most research has focused on the hypocrealean genera Beauveria bassiana, which is a typical filamentous fungus with a high potential for insect control. The morphology and components of fungi are important during the spores germination and outgrow to mycelia. However, to the best of our knowledge, there is no report on the morphology and components of B. bassiana spores and mycelia. In the work, the growth and metabolism of Beauveria bassiana spores and mycelia were studied. High performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to study the metabolism of B. bassiana spores and mycelia. Principal component analysis (PCA) based on HPLC-MS was conducted to study the different components of the spores and mycelia of the fungus. Metabolic network was established based on HPLC-MS and KEGG database. RESULTS Through Gompertz model based on macroscopic and microscopic techniques, spore elongation length was found to increase exponentially until approximately 23.1 h after cultivation, and then growth became linear. In the metabolic network, the decrease of glyoxylate, pyruvate, fumarate, alanine, succinate, oxaloacetate, dihydrothymine, ribulose, acetylcarnitine, fructose-1, 6-bisphosphate, mycosporin glutamicol, and the increase of betaine, carnitine, ergothioneine, sphingosine, dimethyl guanosine, glycerophospholipids, and in spores indicated that the change of the metabolin can keep spores in inactive conditions, protect spores against harmful effects and survive longer. CONCLUSIONS Analysis of the metabolic pathway in which these components participate can reveal the metabolic difference between spores and mycelia, which provide the tools for understand and control the process of of spores germination and outgrow to mycelia.
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Affiliation(s)
- Hongxia Liu
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Xusheng Zhao
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Mingxin Guo
- Jujube Scientific Research and Applied Center, Life Science College, Luoyang Normal University, 471000, Luoyang, P. R. China.
| | - Hui Liu
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui, 230031, P. R. China.
| | - Zhiming Zheng
- Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Sciences and Anhui Province, Hefei, Anhui, 230031, P. R. China.
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Dong LQ, Yang JK, Zhang KQ. Cloning and phylogenetic analysis of the chitinase gene from the facultative pathogen Paecilomyces lilacinus. J Appl Microbiol 2008; 103:2476-88. [PMID: 18045433 DOI: 10.1111/j.1365-2672.2007.03514.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS To PCR-amplify the full-length genomic-encoding sequence for one chitinase from the facultative fungal pathogen Paecilomyces lilacinus, analyse the DNA and deduced amino acid sequences and compare the amino acid sequence with chitinases reported from mycopathogens, entomopathogens and nematopathogens. METHODS AND RESULTS The encoding gene (designated as PLC) was isolated using the degenerate PCR primers and the DNA-Walking method. The gene is 1458 bp in length and contains three putative introns. A number of sequence motifs that might play a role in its regulation and function had also been found. Alignment of the translation product (designated as Plc, molecular mass of 45.783 kDa and pI of 5.65) with homologous sequences from other species showed that Plc belongs to Class V chitinase within the glycosyl hydrolase family 18. The phylogenetic and molecular evolutionary analysis using mega (Molecular Evolutionary Genetics Analysis) indicated that these chitinases from mycopathogens, entomopathogens and nematopathogens, the majority of which belong to glycosyl hydrolase family 18, were clustered into two well-supported subgroups corresponding to ascomycetes fungal and nonfungal chitinases (bacteria, baculoviruses). CONCLUSIONS Our study showed that chitinases from mycoparasitic, entomopathogenic and nematophagous fungi are closely related to each other and reaffirmed the hypothesis that baculovirus chitinase is most likely to be of a bacterial origin - acquired by gene transfer. Bacterial and baculoviral chitinases in our study are potential pathogenicity factors; however, we still cannot ascribe any specific function to those chitinases from the fungi. SIGNIFICANCE AND IMPACT OF THE STUDY To our knowledge, this is the first report describing the chitinase gene and its translation product from Paecilomyces lilacinus, which constitutes the largest number of formulated biological nematicides reported so far, this is also the first study to analyse and resolve the phylogenetic and molecular evolutionary relationships among the chitinases produced by mycopathogens, entomopathogens and nematopathogens.
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Affiliation(s)
- L Q Dong
- Laboratory for Conservation and Utilization of Bio-resources, Yunnan University, Kunming, Yunnan Province, China
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Holder DJ, Kirkland BH, Lewis MW, Keyhani NO. Surface characteristics of the entomopathogenic fungus Beauveria (Cordyceps) bassiana. MICROBIOLOGY-SGM 2007; 153:3448-3457. [PMID: 17906143 DOI: 10.1099/mic.0.2007/008524-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Marked differences in surface characteristics were observed among three types of single-cell propagules produced by the entomopathogenic fungus Beauveria bassiana. Atomic force microscopy (AFM) revealed the presence of bundles or fascicles in aerial conidia absent from in vitro blastospores and submerged conidia. Contact angle measurements using polar and apolar test liquids placed on cell layers were used to calculate surface tension values and the free energies of interaction of the cell types with surfaces. These analyses indicated that the cell surfaces of aerial conidia were hydrophobic, whereas those of blastospores and submerged conidia were hydrophilic. Zeta potential determinations of the electrostatic charge distribution across the surface of the cells varied from +22 to -30 mV for 16-day aerial conidia at pH values ranging from 3 to 9, while the net surface charge ranged from +10 to -13 mV for submerged conidia, with much less variation observed for blastospores, +4 to -4 mV, over the same pH range. Measurements of hydrophobicity using microbial adhesion to hydrocarbons (MATH) indicated that the surfaces of aerial conidia were hydrophobic, and those of blastospores hydrophilic, whereas submerged conidia displayed cell surface characteristics on the borderline between hydrophobic and hydrophilic. Insect pathology assays using tobacco budworm (Heliothis virescens) larvae revealed some variation in virulence among aerial conidia, in vitro blastospores and submerged conidia, using both topical application and haemocoel injection of the fungal cells.
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Affiliation(s)
- Diane J Holder
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Brett H Kirkland
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Michael W Lewis
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Cho EM, Kirkland BH, Holder DJ, Keyhani NO. Phage display cDNA cloning and expression analysis of hydrophobins from the entomopathogenic fungus Beauveria (Cordyceps) bassiana. Microbiology (Reading) 2007; 153:3438-3447. [PMID: 17906142 DOI: 10.1099/mic.0.2007/008532-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hydrophobins are small amphipathic proteins that function in a broad range of growth and developmental processes in fungi. They are involved in the formation of aerial structures, the attachment of fungal cells to surfaces, and act in signalling in response to surface cues and pathogenesis. Beauveria bassiana is an important entomopathogenic fungus used as an arthropod biological control agent. To examine the feasibility of using phage display technology to clone cDNAs encoding hydrophobins, biopanning experiments were performed using a variety of affinity resins, including N,N'-diacetylchitobiose-, fucose-, lactose-, maltose- and melibiose-coupled agarose beads. After five rounds of iterative biopanning, cDNAs corresponding to two B. bassiana (class I) hydrophobins were selectively enriched using melibiose- or lactose-coupled agarose beads. Expression analysis revealed that the hyd1 gene was expressed in all samples tested, including aerial conidia, in vitro blastospores, submerged conidia, and cells sporulating on chitin and insect cuticle, with hyd1 expression peaking in growing mycelia. In contrast, the hyd2 gene was not appreciably expressed in any of the single-cell types (aerial conidia, blastospores and submerged conidia), but was constitutively expressed in growing mycelia and when cells were sporulating on chitin and insect cuticle. MS fingerprinting of an approximately 10 kDa protein found in boiling SDS-insoluble, trifluoroacetic acid-soluble extracts from aerial conidia identified the major component of the B. bassiana rodlet layer to be the hyd2 gene product. These results reveal the differential regulation of the isolated hydrophobins and indicate that phage display represents a novel approach to cDNA cloning of hydrophobins.
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MESH Headings
- Beauveria/chemistry
- Beauveria/genetics
- Beauveria/physiology
- Cloning, Molecular
- DNA, Complementary/genetics
- DNA, Complementary/isolation & purification
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- Fungal Proteins/biosynthesis
- Fungal Proteins/genetics
- Gene Expression Regulation, Fungal/physiology
- Mass Spectrometry
- Molecular Sequence Data
- Mycelium/genetics
- Peptide Library
- RNA, Fungal/biosynthesis
- RNA, Messenger/biosynthesis
- Reverse Transcriptase Polymerase Chain Reaction
- Sequence Analysis, DNA
- Spores, Fungal/genetics
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Affiliation(s)
- Eun-Min Cho
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Brett H Kirkland
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Diane J Holder
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Cho EM, Boucias D, Keyhani NO. EST analysis of cDNA libraries from the entomopathogenic fungus Beauveria (Cordyceps) bassiana. II. Fungal cells sporulating on chitin and producing oosporein. MICROBIOLOGY-SGM 2006; 152:2855-2864. [PMID: 16946279 DOI: 10.1099/mic.0.28845-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In the accompanying paper [Cho, E.-M., Liu, L., Farmerie, W. & Keyhani, N. O. (2006). Microbiology 152, 2843-2854], the analysis of expressed sequence tag (EST) libraries derived from homogeneous single-cell populations of aerial conidia, in vitro blastospores and submerged conidia of the entomopathogenic fungus Beauveria (Cordyceps) bassiana has been reported. Here an extended EST analysis is presented of complex cell mixtures derived from fungal cells sporulating on chitin or grown under culture conditions inducing the production of the B. bassiana secondary metabolite, oosporein. Fungal material used for the construction of the libraries included germinating conidia and blastospores, mycelia, as well as cells in various developmental stages. Approximately 2,500 5' end sequences were determined from random sequencing of clones from each library, and were clustered into 277 contigs with 1,069 singlets, and 306 contigs with 1,064 singlets, for the chitin and oosporein libraries, respectively. Almost half (45-50 %) of the sequences in each library displayed either no significant similarity (e value >10(-4)) or similarity to hypothetical proteins found in the NCBI database. Approximately 20-25 % of the sequences in each library could be annotated by gene ontology terms. A comparative analysis between the two libraries, as well as the libraries in the accompanying paper, is presented. A set of 4,360 clustered and unique sequences was characterized. The data are indicative of a highly plastic gene expression repertoire being available to B. bassiana for growth during different environmental and developmental conditions, and provides a dataset for gene discovery and genome annotation.
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Affiliation(s)
- Eun-Min Cho
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Drion Boucias
- Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Westwood GS, Huang SW, Keyhani NO. Molecular and immunological characterization of allergens from the entomopathogenic fungus Beauveria bassiana. Clin Mol Allergy 2006; 4:12. [PMID: 16995945 PMCID: PMC1594567 DOI: 10.1186/1476-7961-4-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Accepted: 09/22/2006] [Indexed: 11/15/2022] Open
Abstract
Background Entomopathogenic fungi such as Beauveria bassiana are considered promising biological control agents for a variety of arthropod pests. Beauveria species, however, have the potential to elicit allergenic reactions in humans, although no specific allergens have been characterized to date. Methods Four putative allergens were identified within B. bassiana expressed sequence tag (EST) datasets. IgE-reactivity studies were performed using sera from patients displaying mold allergies against recombinant B. bassiana proteins expressed in E. coli. Results Full length cDNA and genomic nucleotide sequences of four potential B. bassiana allergens were isolated. BLASTX search results led to their putative designation as follows; Bb-Eno1, with similarity to fungal enolases; Bb-f2, similar to the Aspergillus fumigatus major allergen, Asp f2 and to a fibrinogen binding mannoprotein; Bb-Ald, similar to aldehyde dehydrogenases; and Bb-Hex, similar to N-acetyl-hexosaminadases. All four genes were cloned into E. coli expression systems and recombinant proteins were produced. Immunoblots of E. coli extracts probed with pooled as well as individual human sera from patients displaying mould allergies demonstrated IgE reactivity versus recombinant Bb-Eno1 and Bb-Ald. Conclusion Four putative Beauveria bassiana allergens were identified. Recombinant proteins corresponding to two of the four, Bb-Eno1 and Bb-Ald were bound by sera IgEs derived from patients with fungal allergies. These data confirm the potential allergenicity of B. bassiana by identification of specific human IgE reactive epitopes.
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Affiliation(s)
- Greg S Westwood
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Shih-Wen Huang
- Department of Pediatrics, University of Florida, College of Medicine, 32610, USA
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Holder DJ, Keyhani NO. Adhesion of the entomopathogenic fungus Beauveria (Cordyceps) bassiana to substrata. Appl Environ Microbiol 2005; 71:5260-6. [PMID: 16151112 PMCID: PMC1214598 DOI: 10.1128/aem.71.9.5260-5266.2005] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The entomopathogenic fungus Beauveria bassiana produces at least three distinct single-cell propagules, aerial conidia, vegetative cells termed blastospores, and submerged conidia, which can be isolated from agar plates, from rich broth liquid cultures, and under nutrient limitation conditions in submerged cultures, respectively. Fluorescently labeled fungal cells were used to quantify the kinetics of adhesion of these cell types to surfaces having various hydrophobic or hydrophilic properties. Aerial conidia adhered poorly to weakly polar surfaces and rapidly to both hydrophobic and hydrophilic surfaces but could be readily washed off the latter surfaces. In contrast, blastospores bound poorly to hydrophobic surfaces, forming small aggregates, bound rapidly to hydrophilic surfaces, and required a longer incubation time to bind to weakly polar surfaces than to hydrophilic surfaces. Submerged conidia displayed the broadest binding specificity, adhering to hydrophobic, weakly polar, and hydrophilic surfaces. The adhesion of the B. bassiana cell types also differed in sensitivity to glycosidase and protease treatments, pH, and addition of various carbohydrate competitors and detergents. The outer cell wall layer of aerial conidia contained sodium dodecyl sulfate-insoluble, trifluoroacetic acid-soluble proteins (presumably hydrophobins) that were not present on either blastospores or submerged conidia. The variations in the cell surface properties leading to the different adhesion qualities of B. bassiana aerial conidia, blastospores, and submerged conidia could lead to rational design decisions for improving the efficacy and possibly the specificity of entomopathogenic fungi for host targets.
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Affiliation(s)
- Diane J Holder
- University of Florida, Microbiology and Cell Science, Bldg. 981, Museum Road, Gainesville, FL 32611, USA
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Kirkland BH, Westwood GS, Keyhani NO. Pathogenicity of entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae to Ixodidae tick species Dermacentor variabilis, Rhipicephalus sanguineus, and Ixodes scapularis. JOURNAL OF MEDICAL ENTOMOLOGY 2004; 41:705-711. [PMID: 15311464 DOI: 10.1603/0022-2585-41.4.705] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Nymphal and adult ticks from three different tick species, Dermacentor variabilis Say, Ixodes scapularis Say, and Rhipicephalus sanguineus Latrielle, were treated with conidia and blastospores of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuill. and Metarhizium anisopliae Metschnikoff. Dose-response experiments indicated that a critical concentration of fungal spores is required for infection and mortality. Over a 28-d time course, fungal suspensions of either B. bassiana or M. anisopliae at 10(8) conidia/ml resulted in 50-70% mortality in adult I. scapularis and R. sanguineus, but <20% mortality in D. variabilis ticks. R. sanguineus nymphs were highly susceptible to both entomopathogenic fungi, displaying >60% mortality within 14 d postinfection and >90% mortality within 21-28 d postinfection. D. variabilis nymphs also were more susceptible than their corresponding adults, displaying mortalities ranging from 20 to 40% 28 d postinfection. I. scapularis nymphs, however, seemed to be slightly less susceptible than adults (45% mortality, 28 d postinfection). The addition of nutrients to fungal cell suspensions did not have any noticeable effects on mortality toward any of the tick species tested. Significant mortality against D. variabilis adults (approximately 65%) was noted only when B. bassiana fungal cells with growth media carryover were used as the inoculum against the ticks. Entomopathogenic fungi such as B. bassiana and M. anisopliae may have the potential for controlling populations of I. scapularis and R. sanguineus, and under certain conditions D. variabilis. Our results indicate that inoculum conditions can greatly affect successful virulence and subsequent mortality.
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Affiliation(s)
- Brett H Kirkland
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
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Padmavathi J, UmaDevi K, Rao CUM, Reddy NNR. Telomere fingerprinting for assessing chromosome number, isolate typing and recombination in the entomopathogen Beauveria bassiana. MYCOLOGICAL RESEARCH 2003; 107:572-80. [PMID: 12884954 DOI: 10.1017/s0953756203007573] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Beauveria bassiana is a popular biocontrol agent used as 'green' pesticide in crop insect pest management. Chromosome number has been variously reported as five, six, seven and eight in this species. The range of chromosome number and the minimum chromosome number in this economically important fungus were assessed through telomere fingerprint analysis of a sample of 17 isolates from different and similar hosts and distant and same geographic origin. Genomic DNA digested with EcoRI, which has no cutting site in the telomere repeat sequence arrays was probed with a radioisotope-labelled (5'-TTAGGG-3')s oligonucleotide. The probe-hybridised regions appeared as discrete bands--each representing a telomere. The number of bands in each lane was counted and halved to arrive at the chromosome number of that isolate. The chromosome number varied from 5 to 10 in the different isolates. The telomere probe hybridised bands were also scored for presence or absence in a 0-1 matrix and a dendrogram based on similarities between the isolates was constructed using the NTSYS-pc ver. 2.02i software. The isolates showed very little similarity; the overall similarity was 14%. Only two isolates which were of diverse host and geographic origin showed 100% similarity. Isolates from the same epizootic that showed 43% similarity in their telomere fingerprints had 96 % similarity in their RAPD (Random amplified polymorphic DNA) fingerprints with 10 primers. The genetic distances computed from any one DNA fingerprinting method thus do not reflect the true genetic similarities of the isolates. The frequency distribution pattern of the pair-wise similarities computed from telomere fingerprints hinted at the occurrence of recombination in this fungus. Telomere fingerprinting proved very useful in typing isolates since each of them was found to have a unique fingerprint. Isolates with the same chromosome number neither showed a distinct morphology or virulence character nor a close similarity in telomere or RAPD fingerprints to merit their subgrouping into a taxonomically relevant or practically useful unit.
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Affiliation(s)
- J Padmavathi
- Department of Botany, Andhra University, Visakhapatnam, 530 003, AP, India
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Abstract
Agricultural use of chemical pesticides has polluted the environment and resulted in resistance among the target organisms. The chemical strategies of pest control are dangerous to both the nontarget organisms in natural habitats and human health. Biological control is an attractive less dangerous possibility for controlling plant pathogens.Some methods of biological control are becoming now commercially available against plant parasitic fungi, nematods and insects. Among filamentous fungi many candidates with biocontrol potential can be found. Fungal biocontrol agents are less effective and reliable than the synthetic pesticides therefore their use in the agricultural practice requires genetic improvement.
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Affiliation(s)
- L Manczinger
- Department of Microbiology, Attila József University, Szeged, Hungary
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Padin SB, Bello GM, Vasicek AL. Pathogenicity ofBeauveria bassiana for adults ofTribolium castaneum (Col.: Tenebrionidae) in stored grains. ACTA ACUST UNITED AC 1997. [DOI: 10.1007/bf02769816] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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