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Wang X, Ding X, Yuan Z, Jia Z, Fu K, Zhan F, Guo W, Zhou L, Li H, Dai J, Wang Z, Xie Y, Yang X. Analysis of the virulence, infection process, and extracellular enzyme activities of Aspergillus nomius against the Asian corn borer, Ostrinia furnacalis guenée (Lepidoptera: Crambidae). Virulence 2023; 14:2265108. [PMID: 37941402 PMCID: PMC10653701 DOI: 10.1080/21505594.2023.2265108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 09/25/2023] [Indexed: 11/10/2023] Open
Abstract
The control of Ostrinia furnacalis, a major pest of maize in Xinjiang, is challenging owing to the occurrence of resistant individuals. Entomopathogenic fungi (EPF) are natural insect regulators used as substitutes for synthetic chemical insecticides. The fungus Aspergillus nomius is highly pathogenic to O. furnacalis; however, its virulence characteristics have not been identified. This study aimed to analyse the lethal efficacy, mode of infection on the cuticle, and extracellular enzyme activity of A. nomius against O. furnacalis. We found that the mortality and mycosis of O. furnacalis were dose-dependent when exposed to A. nomius and varied at different life stages. The egg-hatching and adult emergence rates decreased with an increase in conidial suspension. The highest mortality (83.33%, 7 d post-infection [DPI]) and mycosis (74.33%, 7 DPI) and the lowest mortality response (8.52 × 103 conidia mL-1) and median lethal time (4.91 d) occurred in the 3rd instar larvae of O. furnacalis. Scanning electron microscopy indicated that numerous conidia germination and infection structure formation may have contributed to the high pathogenicity of A. nomius against O. furnacalis. There were significant correlations between O. furnacalis mortality and the activities of extracellular protease, lipase, and chitinase of A. nomius. This study revealed the infection process of the highly pathogenic A. nomius against O. furnacalis, providing a theoretical basis and reference for strain improvement and field application of EPF.
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Affiliation(s)
- Xiaowu Wang
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
| | - Xinhua Ding
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Zihan Yuan
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Zunzun Jia
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Kaiyun Fu
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Faqiang Zhan
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Wenchao Guo
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Liuyan Zhou
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Haiqiang Li
- Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis, Ministry of Agriculture, Ürümqi, PR China
- Institute of Plant Protection, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Jinping Dai
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Zhifang Wang
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Yuqing Xie
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
| | - Xinping Yang
- Institute of Microbiology Applications, Xinjiang Academy of Agricultural Sciences, Ürümqi, PR China
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Li Y, Wang Y, Zhu R, Yang X, Wei M, Zhang Z, Chen C, Zhao P. Tandem Multimerization Can Enhance the Structural Homogeneity and Antifungal Activity of the Silkworm Protease Inhibitor BmSPI39. Cells 2023; 12:cells12050693. [PMID: 36899829 PMCID: PMC10000547 DOI: 10.3390/cells12050693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/05/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Previous studies have shown that BmSPI39, a serine protease inhibitor of silkworm, can inhibit virulence-related proteases and the conidial germination of insect pathogenic fungi, thereby enhancing the antifungal capacity of Bombyx mori. The recombinant BmSPI39 expressed in Escherichia coli has poor structural homogeneity and is prone to spontaneous multimerization, which greatly limits its development and application. To date, the effect of multimerization on the inhibitory activity and antifungal ability of BmSPI39 remains unknown. It is urgent to explore whether a BmSPI39 tandem multimer with better structural homogeneity, higher activity and a stronger antifungal ability can be obtained by protein engineering. In this study, the expression vectors of BmSPI39 homotype tandem multimers were constructed using the isocaudomer method, and the recombinant proteins of tandem multimers were obtained by prokaryotic expression. The effects of BmSPI39 multimerization on its inhibitory activity and antifungal ability were investigated by protease inhibition and fungal growth inhibition experiments. In-gel activity staining and protease inhibition assays showed that tandem multimerization could not only greatly improve the structural homogeneity of the BmSPI39 protein, but also significantly increase its inhibitory activity against subtilisin and proteinase K. The results of conidial germination assays showed that tandem multimerization could effectively enhance the inhibitory ability of BmSPI39 on the conidial germination of Beauveria bassiana. A fungal growth inhibition assay showed that BmSPI39 tandem multimers had certain inhibitory effects on both Saccharomyces cerevisiae and Candida albicans. The inhibitory ability of BmSPI39 against these the above two fungi could be enhanced by tandem multimerization. In conclusion, this study successfully achieved the soluble expression of tandem multimers of the silkworm protease inhibitor BmSPI39 in E. coli and confirmed that tandem multimerization can improve the structural homogeneity and antifungal ability of BmSPI39. This study will not only help to deepen our understanding of the action mechanism of BmSPI39, but also provide an important theoretical basis and new strategy for cultivating antifungal transgenic silkworms. It will also promote its exogenous production and development and application in the medical field.
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Affiliation(s)
- Youshan Li
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, China
- Qinba Mountain Area Collaborative Innovation Center of Bioresources Comprehensive Development, Hanzhong 723001, Shaanxi Province, China
- Correspondence:
| | - Yuan Wang
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, China
| | - Rui Zhu
- Qinba Mountain Area Collaborative Innovation Center of Bioresources Comprehensive Development, Hanzhong 723001, Shaanxi Province, China
| | - Xi Yang
- Qinba State Key Laboratory of Biological Resources and Ecological Environment (Incubation), Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, China
| | - Meng Wei
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, China
| | - Zhaofeng Zhang
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, Shaanxi Province, China
| | - Changqing Chen
- Shaanxi Province Key Laboratory of Bio-Resources, Hanzhong 723001, Shaanxi Province, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
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Gencer D. Isolation and characterization of a high-efficacy Beauveria bassiana strain from the European tent caterpillar, Malacosoma neustria Linnaeus (Lepidoptera: Lasiocampidae). Folia Microbiol (Praha) 2023:10.1007/s12223-023-01037-z. [PMID: 36701018 DOI: 10.1007/s12223-023-01037-z] [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: 09/12/2022] [Accepted: 01/19/2023] [Indexed: 01/27/2023]
Abstract
The European tent caterpillar, Malacosoma neustria Linnaeus (Lepidoptera: Lasiocampidae), is a worldwide known pest that causes significant losses by feeding on many woody and shrub-like plants during the larval period. In this study, a Beauveria bassiana strain isolated from M. neustria larvae and characterized according to its morphological and molecular properties. Its insecticidal activity was tested on M. neustria larvae. Sequence results of partial ITS (ITS1-5.8S-ITS2) gene region identified the isolate (named as Mn1) as a B. bassiana strain. Phylogenetic analysis showed that Mn1 strain displays close similarity to B. bassiana ARSEF 1848 and ARSEF 751 isolates. According to the concentration-responce tests performed using 1 × 103 - 1 × 109 conidia per mL concentrations, LC50 value of the new strain was calculated as 1 × 105 conidia per mL within 7 days against the larvae of M. neustria in the laboratory conditions. B. bassiana Mn1 strain, characterized in this study, is recorded as the first entomopathogenic fungus isolated from M. neustria, and the results showed that new strain of B. bassiana has a serious potential to be utilized as a good biocontrol agent against M. neustria.
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Affiliation(s)
- Donus Gencer
- Salpazari Vocational School, Department of Property Protection and Security, Trabzon University, 61670, Trabzon, Turkey.
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Tong C, Wei J, Pan G, Li C, Zhou Z. Study of Pathogenesis Using Fluorescent Strain of Cordyceps farinosa Revealed Infection of Thitarodes armoricanus Larvae via Digestive Tract. INSECTS 2022; 13:1039. [PMID: 36354862 PMCID: PMC9698661 DOI: 10.3390/insects13111039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/28/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Cordyceps farinosa is often utilized as a biocontrol agent because of its wide host range, strong lethality, and safety for mammals. Artificial rearing of Thitarodes armoricanus larvae is a prerequisite for the artificial cultivation of Chinese cordyceps, and C. farinosa is the most lethal pathogenic fungus during the rearing process. However, the infection process of C. farinosa is still unclear. In this study, we cloned the promoter of the C. farinosa glyceraldehyde 3-phosphate dehydrogenase gene, constructed the EGFP expression cassette, and integrated it into the C. farinosa genome via Agrobacterium transformation. We obtained a fluorescent strain for better observation of the infection process. Using two different inoculation methods of the fluorescent strain, we observed the traditional infection process through the body surface as well as through the digestive tract via feeding. Both infection modes can lead to larval death and mummification. Our findings demonstrated that during the artificial rearing of T. armoricanus, preventing C. farinosa pollution should be an important part of the disinfection of the rearing environment.
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Affiliation(s)
- Chaoqun Tong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Chunfeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
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Distribution and pathogenicity of Beauveria bassiana in soil with earthworm action and feeding. PLoS One 2022; 17:e0275826. [PMID: 36227877 PMCID: PMC9560151 DOI: 10.1371/journal.pone.0275826] [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: 09/19/2021] [Accepted: 09/23/2022] [Indexed: 11/05/2022] Open
Abstract
Earthworm action and feeding have an important impact on a variety of microorganisms in the soil. However, the effects of the earthworm on Beauveria bassiana, a common entomopathogenic fungus in the biological control of pests, have been little studied. In this study, the epigeic earthworm species Eisenia fetida (Savigny) was selected to evaluate its impact on B. bassiana TST05 including its distribution in soil and its pathogenicity to target insects. By testing B. bassiana TST05 distribution, biomass in soil, viable spore germination rate, and pathogenicity to insect larvae after passing through the earthworm gut, the results showed that the activity and feeding of E. fetida promoted the B. bassiana TST05 diffusing downwards in the soil, while decreasing active fungal spores. After passing through the earthworm gut and excretion, the living B. bassiana individuals still had activity and pathogenicity to insects. The germination rate of the viable fungal spores was 15.09% and the infection rate to the insect larvae of Atrijuglans hetaohei Yang reached 62.35%, 80.95% and 100% after infection at 7 d, 10 d, and 14 d, respectively. The results showed that action and feeding of earthworms promoted the distribution of B. bassiana TST05 in soil, but decreased B. bassiana viable spores. This study is important for understanding the interaction between earthworms and B. bassiana in soil and for guiding the scientific application of B. bassiana in the biological control of pests.
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Identification of a Cordyceps fumosorosea Fungus Isolate and Its Pathogenicity against Asian Citrus Psyllid, Diaphorina citri (Hemiptera: Liviidae). INSECTS 2022; 13:insects13040374. [PMID: 35447816 PMCID: PMC9031585 DOI: 10.3390/insects13040374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 12/10/2022]
Abstract
Simple Summary Some entomopathogenic fungi are highly pathogenic to Diaphorina citri, which is the mainly transmitting vector of CLas. In our study, we isolated an entomopathogenic fungus strain from an adult cadaver of D. citri. The isolate was identified as Cordyceps fumosorosea, based on morphology and ITS sequence analysis, and named C. fumosorosea SCAU-CFDC01. We further evaluated its pathogenicity against D. citri nymphs and adults under laboratory and greenhouse conditions. The laboratory results showed that C. fumosorosea SCAU-CFDC01 was most pathogenic to young nymphs, followed by old nymphs and adults. Furthermore, the results on greenhouse experiments revealed that C. fumosorosea SCAU-CFDC01 not only had high pathogenicity against nymphs, but also had serious negative effects on adults from nymphs treated, including emergence rate of adults and female longevity. Our results showed C. fumosorosea SCAU-CFDC01 was highly pathogenic to D. citri, and these findings will facilitate mycoparasite development for biological control of D. citri. Abstract Diaphorina citri is the mainly transmitting vector of the citrus huanglongbing pathogen, which causes severe losses in in the citrus industry. In this study, we isolated a new entomopathogenic fungus, identified as member of Cordyceps fumosorosea based on morphology and ITS sequence analysis. We named C. fumosorosea SCAU-CFDC01 and evaluated its pathogenicity against D. citri nymphs and adults by immersion under laboratory and greenhouse conditions. Results showed that SCAU-CFDC01 was most pathogenic to young nymphs, followed by old nymphs and adults. The LC50 values of the fungus on nymphs and adults showed a declining trend over a 2–7-day period after inoculation. The LT50 (lethal time for a certain concentration to cause 50% mortality) values also presented a decreasing trend along with increasing conidia concentrations. For the results on greenhouse experiments, when 3rd and 5th instar nymphs were inoculated with 1 × 105 conidia mL−1, the survival rate of nymphs were lower, and the emergence rate of adults and female longevity was significantly reduced compared with the control. However, there were no significant effects on sex ratio of adults and male longevity. Our results showed SCAU-CFDC01 was highly pathogenic to D. citri, and may promote mycoparasite development for biological control of D. citri.
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Effect of earthworm Eisenia fetida epidermal mucus on the vitality and pathogenicity of Beauveria bassiana. Sci Rep 2021; 11:13915. [PMID: 34230511 PMCID: PMC8260715 DOI: 10.1038/s41598-021-92694-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 06/07/2021] [Indexed: 02/06/2023] Open
Abstract
Beauveria bassiana is one of the most widely studied and used entomopathogenic fungus as biopesticide. In the biological control of pests, B. bassiana will persist in the soil after application, and will inevitably contact with earthworms, especially the epigeic earthworm species. So, what are the effects of earthworm and its epidermal mucus on the activity of B. bassiana? We employed the epigeic earthworm Eisenia fetida, B. bassiana TST05 strain, and the insect Atrijuglans hetaohei mature larvae to study the impact of earthworm epidermal mucus on the vitality and pathogenicity of B. bassiana to insect. Methods included scanning electron microscope observation, detection of spore germination, fungal extracellular enzyme activity, and infection testing to A. hetaohei. The results showed that the B. bassiana spores may attach to the cuticle of E. fetida but they could be covered by the epidermal mucus and became rough and shrunken. After treatment with the epidermal mucus, the spore germination and extracellular enzymes of B. bassiana was significantly inhibited. Inoculation of A. hetaohei larvae with a mixture of B. bassiana and mucus showed that the mucus could reduce the pathogenicity of B. bassiana to the insect, resulting in a slower disease course and lower mortality. It was concluded that the epidermal mucus of the earthworm E. fetida can inhibit the activity of B. bassiana, as well as the infectivity and pathogenicity of fungus to target insects. However, after treatment with epidermal mucus the surviving B. bassiana still had certain infectivity to insects. This is of great significance for the application of B. bassiana in biological control of pests.
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Lei Y, Hussain A, Guan Z, Wang D, Jaleel W, Lyu L, He Y. Unraveling the Mode of Action of Cordyceps fumosorosea: Potential Biocontrol Agent against Plutella xylostella (Lepidoptera: Plutellidae). INSECTS 2021; 12:insects12020179. [PMID: 33670783 PMCID: PMC7922683 DOI: 10.3390/insects12020179] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/15/2021] [Accepted: 02/16/2021] [Indexed: 12/20/2022]
Abstract
The entomopathogenic fungus, Cordyceps fumosorosea is a potential eco-friendly biocontrol agent. The present study revealed the entire course of infection of P. xylostella by C. fumosorosea with particular reference to cuticular penetration. Comparative studies on the infection of Plutella xylostella larvae by two strains of C. fumosorosea with different pathogenicity were carried out using light, scanning, and transmission electron microscopy. We found that C. fumosorosea tended to adhere to the cuticle surfaces containing protrusions. Although conidia of the lower pathogenic strain IFCF-D58 germinated, they failed to penetrate and complete the development cycle. In contrast, the higher pathogenic strain IFCF01 began to germinate within 4 h and attached to the cuticle by a thin mucilaginous matrix within 8 h post-inoculation. After 24 h post-inoculation, germ tubes and penetrating hyphae reached the cuticular epidermis and began to enter the haemocoel. Within 36 h post-inoculation, the hyphal bodies colonized the body cavity. Hyphae penetrated from inside to outside of the body after 48 h and sporulated the cadavers. After 72 h post-inoculation, numerous conidia emerged and the mycelial covered the entire cuticular surface. The two strains showed similarities in terms of conidial size and germination rate. However, IFCF-D58 exhibited significantly fewer appressoria and longer penetrating hyphae compared to the more infective IFCF01 on all surface topographies. The current pathogen invasion sequence of events suggested that the aggressive growth and propagation along with rapid and massive in vivo production of blastospores facilitate the conidia of IFCF01 to quickly overcome the diamondback moth's defense mechanism.
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Affiliation(s)
- Yanyuan Lei
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.L.); (W.J.); (L.L.)
| | - Abid Hussain
- Institute of Research and Consultancy, King Faisal University, Hofuf 31982, Saudi Arabia;
- Ministry of Environment, Water and Agriculture, Riyadh 11442, Saudi Arabia
| | - Zhaoying Guan
- School of Applied Biology, Shenzhen Institute of Technology, Shenzhen 518116, China;
| | - Desen Wang
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China;
- Key Laboratory of Bio-Pesticide Innovation and Application, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
| | - Waqar Jaleel
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.L.); (W.J.); (L.L.)
| | - Lihua Lyu
- Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China; (Y.L.); (W.J.); (L.L.)
| | - Yurong He
- Department of Entomology, South China Agricultural University, Guangzhou 510642, China;
- Key Laboratory of Bio-Pesticide Innovation and Application, Guangzhou 510642, China
- Engineering Research Center of Biological Control, Ministry of Education, Guangzhou 510642, China
- Correspondence: ; Tel.: +86-20-85283985
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Vertyporokh L, Hułas‐Stasiak M, Wojda I. Host-pathogen interaction after infection of Galleria mellonella with the filamentous fungus Beauveria bassiana. INSECT SCIENCE 2020; 27:1079-1089. [PMID: 31245909 PMCID: PMC7497211 DOI: 10.1111/1744-7917.12706] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/15/2019] [Accepted: 06/17/2019] [Indexed: 06/01/2023]
Abstract
The filamentous fungus Beauveria bassiana is a natural pathogen of the greater wax moth Galleria mellonella. Infection with this fungus triggered systemic immune response in G. mellonella; nevertheless, the infection was lethal if spores entered the insect hemocel. We observed melanin deposition in the insect cuticle and walls of air bags, while the invading fungus interrupted tissue continuity. We have shown colonization of muscles, air bags, and finally colonization and complete destruction of the fat body-the main organ responsible for the synthesis of defense molecules in response to infection. This destruction was probably not caused by simple fungal growth, because the fat body was not destroyed during colonization with a human opportunistic pathogen Candida albicans. This may mean that the infecting fungus is able to destroy actively the insect's fat body as part of its virulence mechanism. Finally, we were unable to reduce the extremely high virulence of B. bassiana against G. mellonella by priming of larvae with thermally inactivated fungal spores.
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Affiliation(s)
- Lidiia Vertyporokh
- Faculty of Biology and Biotechnology, Department of Immunobiology, Institute of Biology and BiochemistryMaria Curie‐Sklodowska UniversityAkademicka 19LublinPoland
| | - Monika Hułas‐Stasiak
- Faculty of Biology and Biotechnology, Department of Comparative Anatomy and Anthropology, Institute of Biology and BiochemistryMaria Curie‐Sklodowska UniversityAkademicka 19LublinPoland
| | - Iwona Wojda
- Faculty of Biology and Biotechnology, Department of Immunobiology, Institute of Biology and BiochemistryMaria Curie‐Sklodowska UniversityAkademicka 19LublinPoland
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Ou D, Zhang LH, Guo CF, Chen XS, Ali S, Qiu BL. Identification of a new Cordyceps javanica fungus isolate and its toxicity evaluation against Asian citrus psyllid. Microbiologyopen 2018; 8:e00760. [PMID: 30421866 PMCID: PMC6562118 DOI: 10.1002/mbo3.760] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/02/2018] [Accepted: 10/02/2018] [Indexed: 11/09/2022] Open
Abstract
The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most serious pest of citrus worldwide. It acts as a vector for a group of phloem‐limited bacteria (Candidatus Liberibacter spp.) that causes Huanglongbing (HLB) disease. Thus, D. citri management is an important strategy against HLB, and biological control is currently considered as the most effective method because of the unsustainable and negative side effects of chemical control. Here, we isolated a new strain of entomopathogenic fungus, Cordyceps javanica (GZQ‐1), from one cadaver of D. citri adult based on its morphological and phylogenetic data. Five conidial concentrations of the C. javanica pathogen (1 × 103, 1 × 104, 1 × 105, 1 × 106, and 1 × 107 conidia/ml) were assessed against six life stages of D. citri (1st‐5th instar nymphs and adults). Results showed that C. javanica GZQ‐1 was highly pathogenic to D. citri nymphs (69.49%–90.87% mortality) and adults (69.98% mortality). The LC50 and LT50 values of C. javanica against 1st‐2nd instar (younger), 3rd‐4th instar (middle aged), 5th instar (older), and adults were 1.20 × 105, 1.10 × 106, 4.47 × 106, 8.12 × 106 conidia/ml and 4.25, 4.51, 5.17, 5.49 days, respectively. Moreover, glasshouse experiments indicated that this C. javanica GZQ‐1 caused higher infection rates of D. citri adults compared to two other fungal strains we previously isolated in the laboratory, Cordyceps fumosorosea (IF010) and Metarhizium anisopliae (CNGD7).
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Affiliation(s)
- Da Ou
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou, China
| | - Li-He Zhang
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou, China
| | - Chang-Fei Guo
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou, China
| | - Xiao-Sheng Chen
- College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou, China
| | - Shaukat Ali
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou, China.,Engineering Research Center of Biological Control, Ministry of Education, Guangzhou, China
| | - Bao-Li Qiu
- Key Laboratory of Bio-Pesticide Innovation and Application, South China Agricultural University, Guangzhou, China.,Engineering Research Center of Biological Control, Ministry of Education, Guangzhou, China
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Sun T, Wang XQ, Zhao ZL, Yu SH, Yang P, Chen XM. A Lethal Fungus Infects the Chinese White Wax Scale Insect and Causes Dramatic Changes in the Host Microbiota. Sci Rep 2018; 8:5324. [PMID: 29593315 PMCID: PMC5871785 DOI: 10.1038/s41598-018-23671-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 03/13/2018] [Indexed: 11/09/2022] Open
Abstract
The Chinese white wax scale insect (Ericerus pela) is an economically valuable species with an important role in wax production. Recently, in a greenhouse in Kunming, we identified a genus of fungus that infects and kills E. pela females. This study sought to perform the molecular detection of entomopathogens and analyze the changes in the host microbiota after entomopathogen infection. We used library construction, high-throughput sequencing and real-time quantitative polymerase chain reaction (RT-qPCR) to identify the fungi infecting adult E. pela, to understand the changes in the host organism, and to determine the distribution of the entomopathogens. Cladosporium langeronii and C. sphaerospermum were the main pathogenic species that infected the E. pela females, and they were most prevalent in the dorsal cuticle. In vivo, after infection, the proportion of Cladosporium clearly increased. The infection had little influence on the fungal community but had a strong influence on the bacterial community. After infection, Arsenophonus was dominant, and numerous bacterial genera disappeared. However, Rickettsia, instead of Arsenophonus, became dominant in the Cladosporium-infected individuals that had also been infected with Rickettsia. We identified the species that infected E. pela females and determined the influence of infection on the host microorganisms.
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Affiliation(s)
- Tao Sun
- Research Institute of Resources Insects, Chinese Academy of Forestry, Key laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming, 650224, China
| | - Xue-Qing Wang
- Research Institute of Resources Insects, Chinese Academy of Forestry, Key laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming, 650224, China
| | - Zun-Ling Zhao
- Research Institute of Resources Insects, Chinese Academy of Forestry, Key laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming, 650224, China
| | - Shu-Hui Yu
- College of Agronomy, Kunming University, Kunming, 650214, China
| | - Pu Yang
- Research Institute of Resources Insects, Chinese Academy of Forestry, Key laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming, 650224, China.
| | - Xiao-Ming Chen
- Research Institute of Resources Insects, Chinese Academy of Forestry, Key laboratory of Cultivating and Utilization of Resources Insects of State Forestry Administration, Kunming, 650224, China.
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12
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Proboscis infection route of Beauveria bassiana triggers early death of Anopheles mosquito. Sci Rep 2017; 7:3476. [PMID: 28615623 PMCID: PMC5471193 DOI: 10.1038/s41598-017-03720-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 05/03/2017] [Indexed: 11/08/2022] Open
Abstract
Entomopathogenic fungi are known to control vector mosquito populations. Thus, understanding the infection dynamics of entomopathogenic fungi is crucial for the effective control of insect pests such as mosquitoes. We investigated the dynamics of Beauveria bassiana s.l. 60-2 infection of Anopheles stephensi by exposing the mosquito to fungus-impregnated filter paper through two infection routes and then comparing the mortality and extent of infection. Fungal development was observed after using this inoculation method with both the tarsus route and the proboscis route, but early mosquito death occurred only after infection through the proboscis route. Fungal hyphae invaded almost all the tissues and organs before or after the death of the host, and fungal invasion of the brain was highly correlated with mortality. Moreover, although all mosquitoes that were alive at various time points after inoculation showed no fungal infection in the brain, fungal infection was detected in the brain in all dead mosquitoes. Our results suggest that fungal invasion of the brain represents one of the factors affecting mortality, and that the proboscis route of infection is critical for the early death of vector mosquitoes.
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13
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Guo X, Dong Z, Zhang Y, Li Y, Liu H, Xia Q, Zhao P. Proteins in the Cocoon of Silkworm Inhibit the Growth of Beauveria bassiana. PLoS One 2016; 11:e0151764. [PMID: 27032085 PMCID: PMC4816445 DOI: 10.1371/journal.pone.0151764] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/03/2016] [Indexed: 12/31/2022] Open
Abstract
Silk cocoons are composed of fiber proteins (fibroins) and adhesive glue proteins (sericins), which provide a physical barrier to protect the inside pupa. Moreover, other proteins were identified in the cocoon silk, many of which are immune related proteins. In this study, we extracted proteins from the silkworm cocoon by Tris-HCl buffer (pH7.5), and found that they had a strong inhibitory activity against fungal proteases and they had higher abundance in the outer cocoon layers than in the inner cocoon layers. Moreover, we found that extracted cocoon proteins can inhibit the germination of Beauveria bassiana spores. Consistent with the distribution of protease inhibitors, we found that proteins from the outer cocoon layers showed better inhibitory effects against B. bassiana spores than proteins from the inner layers. Liquid chromatography-tandem mass spectrometry was used to reveal the extracted components in the scaffold silk, the outermost cocoon layer. A total of 129 proteins were identified, 30 of which were annotated as protease inhibitors. Protease inhibitors accounted for 89.1% in abundance among extracted proteins. These protease inhibitors have many intramolecular disulfide bonds to maintain their stable structure, and remained active after being boiled. This study added a new understanding to the antimicrobial function of the cocoon.
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Affiliation(s)
- Xiaomeng Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Zhaoming Dong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yan Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Youshan Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Huawei Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- * E-mail:
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Li Y, Zhao P, Liu H, Guo X, He H, Zhu R, Xiang Z, Xia Q. TIL-type protease inhibitors may be used as targeted resistance factors to enhance silkworm defenses against invasive fungi. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2015; 57:11-19. [PMID: 25453359 DOI: 10.1016/j.ibmb.2014.11.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 10/30/2014] [Accepted: 11/21/2014] [Indexed: 06/04/2023]
Abstract
Entomopathogenic fungi penetrate the insect cuticle using their abundant hydrolases. These hydrolases, which include cuticle-degrading proteases and chitinases, are important virulence factors. Our recent findings suggest that many serine protease inhibitors, especially TIL-type protease inhibitors, are involved in insect resistance to pathogenic microorganisms. To clarify the molecular mechanism underlying this resistance to entomopathogenic fungi and identify novel genes to improve the silkworm antifungal capacity, we conducted an in-depth study of serine protease inhibitors. Here, we cloned and expressed a novel silkworm TIL-type protease inhibitor, BmSPI39. In activity assays, BmSPI39 potently inhibited the virulence protease CDEP-1 of Beauveria bassiana, suggesting that it might suppress the fungal penetration of the silkworm integument by inhibiting the cuticle-degrading proteases secreted by the fungus. Phenol oxidase activation studies showed that melanization is involved in the insect immune response to fungal invasion, and that fungus-induced excessive melanization is suppressed by BmSPI39 by inhibiting the fungal cuticle-degrading proteases. To better understand the mechanism involved in the inhibition of fungal virulence by protease inhibitors, their effects on the germination of B. bassiana conidia was examined. BmSPI38 and BmSPI39 significantly inhibited the germination of B. bassiana conidia. Survival assays showed that BmSPI38 and BmSPI39 markedly improved the survival rates of silkworms, and can therefore be used as targeted resistance proteins in the silkworm. These results provided new insight into the molecular mechanisms whereby insect protease inhibitors confer resistance against entomopathogenic fungi, suggesting their potential application in medicinal or agricultural fields.
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Affiliation(s)
- Youshan Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China; Vitamin D Research Institute, Shannxi University of Technology, Hanzhong 723001, Shannxi Province, China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Huawei Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Xiaomeng Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Huawei He
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Rui Zhu
- School of Management, Shannxi University of Technology, Hanzhong 723001, Shannxi Province, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
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