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Ge S, Xie Y, Ding K, Xu S, Xu H, Chang X, Li H, Wang R, Luo Z, Shan Y, Ding S. The combination of metabolome and transcriptome clarifies the inhibition of the Alternaria toxin accumulation by methyl ferulate. Food Chem 2024; 456:140060. [PMID: 38878540 DOI: 10.1016/j.foodchem.2024.140060] [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: 03/07/2024] [Revised: 05/17/2024] [Accepted: 06/09/2024] [Indexed: 07/24/2024]
Abstract
As one of the most typical pathogens in fruit postharvest diseases, Alternaria alternata (A. alternata) can produce Alternaria toxins (ATs) aggravating fruit decay and harming human health. In this study, ATs (tenuazonic acid, alternariol monomethyl ether, and alternariol) production was inhibited effectively by 200 and 8000 mg/L MF (methyl ferulate) in vitro and in vivo. 1-Octen-3-ol and 3-octanol were the potential iconic volatile organic compounds of ATs (R2 > 0.99). MF induced oxidative stress, resulting in physiological and metabolic disorders, membrane lipid oxidation and cell damage. It decreased precursors and energy supply by disturbing amino acid metabolism, ABC transporters, citrate cycle, pentose and glucuronate interconversions to regulate ATs synthesis. MF down-regulated the genes related to ATs synthesis (PksJ, AaTAS1, and OmtI), transport (AaMFS1 and MFS), and pathogenicity to affect ATs production and virulence. This study provided a theoretical basis for the control of ATs production.
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Affiliation(s)
- Shuai Ge
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Ying Xie
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Ke Ding
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Saiqing Xu
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Haishan Xu
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Xia Chang
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Huan Li
- DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Rongrong Wang
- College of Food Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Zisheng Luo
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310000, China
| | - Yang Shan
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China
| | - Shenghua Ding
- Longping Branch, College of Biology, Hunan University, Changsha 410125, China; DongTing Laboratory, Hunan Agricultural Product Processing Institute, Hunan Academy of Agricultural Sciences, Changsha 410125, China.
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Abstract
The entomopathogenic fungus Beauveria bassiana is a typical filamentous fungus and has been used for pest biocontrol. Conidia are the main active agents of fungal pesticides; however, we know little about conidial developmental mechanisms and less about maturation mechanisms. We found that a Zn2Cys6 transcription factor of B. bassiana (named BbCmr1) was mainly expressed in late-stage conidia and was involved in conidium maturation regulation. Deletion of Bbcmr1 impaired the conidial cell wall and resulted in a lower conidial germination rate under UV (UV), heat shock, H2O2, Congo red (CR) and SDS stresses compared to the wild type. Transcription levels of the genes associated with conidial wall components and trehalose synthase were significantly reduced in the ΔBbcmr1 mutant. Further analysis found that BbCmr1 functions by upregulating BbWetA, a well-known transcription factor in the central development of BrlA-AbaA-WetA. The expression of Bbcmr1 was positively regulated by BbBrlA. These results indicated that BbCmr1 played important roles in conidium maturation by interacting with the central development pathway, which provided insight into the conidial development networks in B. bassiana. IMPORTANCE Conidium maturation is a pivotal event in conidial development and affects fungal survival ability under various biotic/abiotic stresses. Although many transcription factors have been reported to regulate conidial development, we know little about the molecular mechanism of conidium maturation. Here, we demonstrated that the transcription factor BbCmr1 of B. bassiana was involved in conidium maturation, regulating cell wall structure, the expression of cell wall-related proteins, and trehalose synthesis. BbCmr1 orchestrated conidium maturation by interplaying with the central development pathway BrlA-AbaA-WetA. BbBrlA positively regulated the expression of Bbcmr1, and the latter positively regulated BbwetA expression, which forms a regulatory network mediating conidial development. This finding was critical to understand the molecular regulatory networks of conidial development in B. bassiana and provided avenues to engineer insect fungal pathogens with high-quality conidia.
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Slt2-MAPK/RNS1 Controls Conidiation via Direct Regulation of the Central Regulatory Pathway in the Fungus Metarhizium robertsii. J Fungi (Basel) 2021; 8:jof8010026. [PMID: 35049966 PMCID: PMC8779605 DOI: 10.3390/jof8010026] [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: 12/09/2021] [Revised: 12/25/2021] [Accepted: 12/27/2021] [Indexed: 01/18/2023] Open
Abstract
Ascomycete fungi usually produce small hydrophobic asexual conidia that are easily dispersed and essential for long-term survival under a variety of environmental conditions. Several upstream signaling regulators have been documented to control conidiation via regulation of the central regulatory pathway that contains the transcription factors BrlA, AbaA and WetA. Here, we showed that the Slt2-MAPK signaling pathway and the transcription factor RNS1 constitute a novel upstream signaling cascade that activates the central regulatory pathway for conidiation in the Ascomycetes fungus M. robertsii. The BrlA gene has two overlapping transcripts BrlAα and BrlAβ; they have the same major ORF, but the 5' UTR of BrlAβ is 835 bp longer than the one of BrlAα. During conidiation, Slt2 phosphorylates the serine residue at the position 306 in RNS1, which self-induces. RNS1 binds to the BM2 motif in the promoter of the BrlA gene and induces the expression of the transcript BlrAα, which in turn activates the expression of the genes AbaA and WetA. In conclusion, the Slt2/RNS1 cascade represents a novel upstream signaling pathway that initiates conidiation via direct activation of the central regulatory pathway. This work provides significant mechanistic insights into the production of asexual conidia in an Ascomycete fungus.
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Zhao K, Liu Z, Li M, Hu Y, Yang L, Song X, Qin Y. Drafting Penicillium oxalicum calcineurin-CrzA pathway by combining the analysis of phenotype, transcriptome, and endogenous protein-protein interactions. Fungal Genet Biol 2021; 158:103652. [PMID: 34920105 DOI: 10.1016/j.fgb.2021.103652] [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: 08/13/2021] [Revised: 11/17/2021] [Accepted: 12/08/2021] [Indexed: 11/04/2022]
Abstract
Fungi sense environmental signals and coordinate growth, development, and metabolism accordingly. Calcium-calmodulin-calcineurin signaling is a conserved cascade pathway in fungi. One of the most important downstream targets of this pathway is the transcription factor Crz1/CrzA, which plays an essential role in various cellular processes. The putative collaborators of Penicillium oxalicum CrzA (PoCrzA) were found, through tandem affinity purification followed by mass spectrometric analysis (TAP-MS). A total of 50 protein-protein interaction collaborators of PoCrzA were observed. Among them, some collaborators, such as the catalytic subunit of calcineurin (Cna1, calcineurin A), the regulatory catalytic subunit of calcineurin (Cnb1, calcineurin B), and a 14-3-3 protein Bmh1, which were previously reported in yeast, were identified. Some putative collaborators, including two karyopherins (exportin Los1 and importin Srp1), two kinases (Fus3 and Slt2p), and a general transcriptional corepressor (Cyc8), were also found. The CrzA deletion mutant ΔPocrzA exhibited slow hyphal growth, impaired conidiogenesis, and reduced extracellular cellulase synthesis. Phenotype and transcriptome analysis showed that PoCrzA regulated fungal development in a Flbs-BrlA-dependent manner and participated in cellulase synthesis by modulating cellulolytic gene expression. On the basis of the results of TAP-MS, transcriptome, and phenotypic analysis in P. oxalicum, our study was the first to draft the calcineurin-CrzA pathway in cellulolytic fungi.
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Affiliation(s)
- Kaili Zhao
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Zhongjiao Liu
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Mengxue Li
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yueyan Hu
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Ling Yang
- Vocational Education College, Dezhou University, Dezhou 253023, China.
| | - Xin Song
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
| | - Yuqi Qin
- National Glycoengineering Research Center, Shandong University, No. 72 Binhai Road, Qingdao 266237, China; State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, No. 72 Binhai Road, Qingdao 266237, China.
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Hu P, Ding H, Shen L, He GJ, Liu H, Tian X, Tao C, Bai X, Liang J, Jin C, Xu X, Yang E, Wang L. A unique cell wall synthetic response evoked by glucosamine determines pathogenicity-associated fungal cellular differentiation. PLoS Genet 2021; 17:e1009817. [PMID: 34624015 PMCID: PMC8500725 DOI: 10.1371/journal.pgen.1009817] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 09/09/2021] [Indexed: 11/24/2022] Open
Abstract
The yeast-to-hypha transition is tightly associated with pathogenicity in many human pathogenic fungi, such as the model fungal pathogen Cryptococcus neoformans, which is responsible for approximately 180,000 deaths annually. In this pathogen, the yeast-to-hypha transition can be initiated by distinct stimuli: mating stimulation or glucosamine (GlcN), the monomer of cell wall chitosan. However, it remains poorly understood how the signal specificity for Cryptococcus morphological transition by disparate stimuli is ensured. Here, by integrating temporal expression signature analysis and phenome-based clustering evaluation, we demonstrate that GlcN specifically triggers a unique cellular response, which acts as a critical determinant underlying the activation of GlcN-induced filamentation (GIF). This cellular response is defined by an unusually hyperactive cell wall synthesis that is highly ATP-consuming. A novel cell surface protein Gis1 was identified as the indicator molecule for the GlcN-induced cell wall response. The Mpk1-directed cell wall pathway critically bridges global cell wall gene induction and intracellular ATP supply, ensuring the Gis1-dependent cell wall response and the stimulus specificity of GIF. We further reveal that the ability of Mpk1 to coordinate the cell wall response and GIF activation is conserved in different Cryptococcus pathogens. Phosphoproteomics-based profiling together with genetic and phenotypic analysis revealed that the Mpk1 kinase mediates the regulatory specificity of GIF through a coordinated downstream regulatory network centered on Skn7 and Crz1. Overall, our findings discover an unprecedented and conserved cell wall biosynthesis-dependent fungal differentiation commitment mechanism, which enables the signal specificity of pathogenicity-related dimorphism induced by GlcN in Cryptococcus pathogens. Many human fungal pathogens can undergo dimorphic transition between yeast and hyphal forms in response to different external stimuli, and this morphological transition is generally and critically linked with their infections. In Cryptococcus neoformans, a model pathogenic fungus, the yeast-to-hypha transition can be elicited by mating stimulation or glucosamine (GlcN), the monomer of cell wall chitosan. Here, we show that GlcN specifically evokes a unique hyperactive cell wall synthetic response, which determines GlcN-induced filamentation (GIF) as a key commitment event. The Mpk1-directed cell wall signaling pathway as a core and conserved cascade connects the cell wall synthetic response and GIF activation in different Cryptococcus pathogens. Overall, the findings reveal a previously unrecognized function of GlcN in stimulating cell wall signaling and biosynthetic machinery, which enables a unique dimorphism commitment mechanism underlying the signal specificity of the mating-independent yeast-to-hypha transition in Cryptococcus pathogens.
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Affiliation(s)
- Pengjie Hu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Hao Ding
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lan Shen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Guang-Jun He
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Huimin Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Science and Technology of China (USTC), Hefei, China
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Changyu Tao
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xiangzheng Bai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jingnan Liang
- Public Technology Service Center, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Cheng Jin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xinping Xu
- The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Ence Yang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- * E-mail:
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Zhao X, Luo T, Huang S, Peng N, Yin Y, Luo Z, Zhang Y. A novel transcription factor negatively regulates antioxidant response, cell wall integrity and virulence in the fungal insect pathogen, Beauveria bassiana. Environ Microbiol 2021; 23:4908-4924. [PMID: 33432709 DOI: 10.1111/1462-2920.15397] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 01/01/2023]
Abstract
Genomic data have identified a class of fungal specific transcription factors (FsTFs) that are thought to regulate unique aspects of fungal gene expression, although the functions of many of these proteins remain unknown. Here, a novel FsTF (BbStf1), which features a leucine zipper dimerization domain and a fungal transcription factor regulatory middle homology region, was characterized in Beauveria bassiana, a filamentous insect fungal pathogen. Transcriptional activation and nuclear localization were experimentally confirmed for BbStf1. Disruption of Bbstf1 resulted in increased tolerance to oxidative stress and cell wall perturbation, accompanied by increased peroxidase (POD) and superoxide dismutase (SOD) activities and ratio of reduced/oxidized glutathione (GSH/GSSG), and by thickened cell wall and altered composition. Gene expression profile analysis revealed that transcription patterns of antioxidant enzyme and cell wall integrity-involved genes were altered in the ∆Bbstf1, including some BbStf1-targeted genes clarified with evidence. The ∆Bbstf1 strain displayed greater virulence to Galleria mellonella in the bioassays through both topical infection and intrahaemocoel injection due to more rapid proliferation in the haemocoel as compared to the wild-type strain. Altogether, BbStf1 acts as a negative regulator of antioxidant response, cell wall integrity and virulence in B. bassiana.
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Affiliation(s)
- Xin Zhao
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Tingying Luo
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Shuaishuai Huang
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Ning Peng
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Ying Yin
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Zhibing Luo
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
| | - Yongjun Zhang
- Academy of Agricultural Sciences, Biotechnology Research Center, Southwest University, Chongqing, 400715, People's Republic of China
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Lu Z, Deng J, Wang H, Zhao X, Luo Z, Yu C, Zhang Y. Multifunctional role of a fungal pathogen-secreted laccase 2 in evasion of insect immune defense. Environ Microbiol 2021; 23:1256-1274. [PMID: 33393158 DOI: 10.1111/1462-2920.15378] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 12/25/2020] [Accepted: 12/26/2020] [Indexed: 11/29/2022]
Abstract
Laccases are widely present in bacteria, fungi, plants and invertebrates and involved in a variety of physiological functions. Here, we report that Beauveria bassiana, an economic important entomopathogenic fungus, secretes a laccase 2 (BbLac2) during infection that detoxifies insect immune response-generated reactive oxygen species (ROS) and interferes with host immune phenoloxidase (PO) activation. BbLac2 is expressed in fungal cells during proliferation in the insect haemocoel and can be found to distribute on the surface of haemolymph-derived in vivo fungal hyphal bodies or be secreted. Targeted gene-knockout of BbLac2 increased fungal sensitivity to oxidative stress, decreased virulence to insect, and increased host PO activity. Strains overexpressing BbLac2 showed increased virulence, with reduced host PO activity and lowered ROS levels in infected insects. In vitro assays revealed that BbLac2 could eliminate ROS and oxidize PO substrates (phenols), verifying the enzymatic functioning of the protein in detoxification of cytotoxic ROS and interference with the PO cascade. Moreover, BbLac2 acted as a cell surface protein that masked pathogen associated molecular patterns (PAMPs), enabling the pathogen to evade immune recognition. Our data suggest a multifunctional role for fungal pathogen-secreted laccase 2 in evasion of insect immune defenses.
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Affiliation(s)
- Zhuoyue Lu
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Juan Deng
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Huifang Wang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Xin Zhao
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Zhibing Luo
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Chenxi Yu
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
| | - Yongjun Zhang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Southwest University, Chongqing, 400715, P. R. China
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Metarhizium Anisopliae Challenges Immunity and Demography of Plutella xylostella. INSECTS 2020; 11:insects11100694. [PMID: 33065996 PMCID: PMC7600445 DOI: 10.3390/insects11100694] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 12/18/2022]
Abstract
Simple Summary The diamondback moth, Plutella xylostella, is a destructive pest of cruciferous crops worldwide. Integrated pest management (IPM) strategies, largely involve the use chemical pesticides which are harmful for the environment and human health. In this study, the virulence of three species of entomopathogenic fungi were tested. Metarhizium anisopliae proved to be the most effective by killing more than 90% of the population. Based on which the fungus was selected to study the host-pathogen immune interactions. More precisely, after infection, superoxide dismutase (SOD) and phenoloxidase (PO), two major enzymes involved in immune response, were studied at different time points. The fungus gradually weakened the enzyme activities as the time progressed, indicating that physiological attributes of host were adversely affected. The expression of immune-related genes (Defensin, Spaetzle, Cecropin, Lysozyme, and Hemolin) varied on different time points. Moreover, the fungus negatively impacted the development of the host by reducing the life span and egg laying ability. Thus, M. anisopliae can become a potent prospect for the control of this pest. This information will also reinforce the development of policies for biocontrol-based pest management. Abstract Entomopathogenic fungi are naturally existing microbes, that can serve as a key regulator of insect pests in integrated pest management strategies. Besides having no hazardous effects on the environment, these entomopathogens are alternatives to synthetic insecticides that can control notorious insect-like Plutella xylostella, a destructive pest of cruciferous crops. Three different species of entomopathogenic fungi were evaluated before the selection (high larval mortality and least LC50) of Metarhizum anisopliae. The study was designed to investigate the mortality, development, and immune responses of P. xylostella when challenged with M. anisopliae, a naturally existing soil-borne entomopathogenic fungus. M. anisopliae resulted in high pest mortality by killing 93% of larvae. However, no statistically significant effect on hemocyte concentration was observed. The activity of enzymes (Phenoloxidase and Superoxide dismutase) and immune genes (Defensin, Spaetzle, Cecropin, Lysozyme, and Hemolin) did vary at different time points (24, 48, 72 and 96 h) after exposure to M. anisopliae. Disturbance in the biological cycles of P. xylostella was also detected, significantly shorter adult life span (8.11:6.87, M:F) and reduced fecundity (101 eggs/female) were observed along with disturbed larval and pupal duration. Results suggest that M. anisopliae can efficiently hinder the P. xylostella defense and developmental system, resulting in mortality and disturbed demography.
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Chen JF, Liu Y, Tang GR, Jin D, Chen X, Pei Y, Fan YH. The secondary metabolite regulator, BbSmr1, is a central regulator of conidiation via the BrlA-AbaA-WetA pathway in Beauveria bassiana. Environ Microbiol 2020; 23:810-825. [PMID: 32691932 DOI: 10.1111/1462-2920.15155] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/27/2020] [Accepted: 07/04/2020] [Indexed: 01/21/2023]
Abstract
The filamentous fungus Beauveria bassiana, an insect fungal pathogen, is widely used for pest biocontrol. Aerial conidia are infectious propagules, and their yield and viability greatly affect the field application of this fungus; however, little is known about the molecular regulatory mechanism of the triggered conidiation. In the present study, we find that the secondary metabolite regulator BbSmr1 is involved in the regulation of asexual conidiation development and stress response in B. bassiana. A deficiency in Bbsmr1 results in a prominent fluffy-like phenotype on solid medium, decreased conidial yield, accelerated conidial germination, as well as increased tolerance to H2 O2 stress and cell wall inhibitors. The deletion of Bbsmr1 also leads to thickened conidial cell walls and changed cell epitopes. Overexpressing either BbbrlA or BbabaA in the ∆Bbsmr1 strain can rescue the phenotypes of conidial development and stress response. BbSmr1 activates BbbrlA transcription by directly binding to the A4GA3 sequence of the BbbrlA promoter. BbBrlA in turn binds to the promoter of Bbsmr1 and negatively regulates the expression of Bbsmr1. These results indicate that BbSmr1 positively regulates conidial development in B. bassiana by activating the central development pathway BrlA-AbaA-WetA and provides insights into the developmental regulatory mechanism of entomopathogenic fungi.
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Affiliation(s)
- Jin-Feng Chen
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China.,College of Biological and Chemical Engineering, Chongqing University of Education, Chongqing, 400067, China
| | - Yu Liu
- College of Biotechnology, Southwest University, Beibei, Chongqing, 400716, China
| | - Gui-Rong Tang
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Dan Jin
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Xi Chen
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Yan Pei
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
| | - Yan-Hua Fan
- State Key Laboratory of Silkworm Genome Biology, Biotechnology Research Center, Southwest University, Chongqing, 400716, China
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Phenotypic and molecular insights into heat tolerance of formulated cells as active ingredients of fungal insecticides. Appl Microbiol Biotechnol 2020; 104:5711-5724. [PMID: 32405755 DOI: 10.1007/s00253-020-10659-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/23/2020] [Accepted: 04/29/2020] [Indexed: 12/25/2022]
Abstract
Formulated conidia of insect-pathogenic fungi, such as Beauveria and Metarhizium, serve as the active ingredients of fungal insecticides but are highly sensitive to persistent high temperatures (32-35 °C) that can be beyond their upper thermal limits especially in tropical areas and during summer months. Fungal heat tolerance and inter- or intra-specific variability are critical factors and limitations to field applications of fungal pesticides during seasons favoring outbreaks of pest populations. The past decades have witnessed tremendous advances in improving fungal pesticides through selection of heat-tolerant strains from natural isolates, improvements and innovations in terms of solid-state fermentation technologies for the production of more heat-tolerant conidia, and the use of genetic engineering of candidate strains for enhancing heat tolerance. More recently, with the entry into a post-genomic era, a large number of signaling and effector genes have been characterized as important sustainers of heat tolerance in both Beauveria and Metarhizium, which represent the main species used as fungal pesticides worldwide. This review focuses on recent advances and provides an overview into the broad molecular basis of fungal heat tolerance and its multiple regulatory pathways. Emphases are placed on approaches for screening of heat-tolerant strains, methods for optimizing conidial quality linked to virulence and heat tolerance particularly involving cell wall architecture and optimized trehalose/mannitol contents, and how molecular determinants can be exploited for genetic improvement of heat tolerance and pest-control potential. Examples of fungal pesticides with different host spectra and their appropriateness for use in apiculture are given. KEY POINTS: • Heat tolerance is critical for field stability and efficacy of fungal insecticides. • Inter- and intra-specific variability exists in insect-pathogenic fungi. • Optimized production technology and biotechnology can improve heat tolerance. • Fungal heat tolerance is orchestrated by multiple molecular pathways.
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The MAP kinase AflSlt2 modulates aflatoxin biosynthesis and peanut infection in the fungus Aspergillus flavus. Int J Food Microbiol 2020; 322:108576. [PMID: 32240921 DOI: 10.1016/j.ijfoodmicro.2020.108576] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 02/21/2020] [Accepted: 02/29/2020] [Indexed: 12/20/2022]
Abstract
Aflatoxin contamination in food and feed products has been brought into sharp focus over the last few decades in the world. However, there is no effective strategy for solving the problem thus far. Therefore, basic research on the aflatoxin-producer Aspergillus flavus is an urgent need. The vital role of mitogen-activated protein kinases (MAPKs) in signal transduction has been documented in various pathogenic fungi, but their functions in A. flavus have rarely been investigated. Herein, we characterized the detailed function of one of these MAPKs, AflSlt2. Targeted deletion of AflSlt2 gene indicates that this kinase is required for vegetative growth, conidia generation, and sclerotium formation. The analysis of AflSlt2 deletion mutant revealed hypersensitivity to cell wall-damaging chemicals and resistance against hydrogen peroxide. Interestingly, the ability of the ΔAflSlt2 mutant to generate aflatoxins in medium was significantly increased compared to wild type. However, a pathogenicity assay indicated that the ΔAflSlt2 mutant was deficient in peanut infection. Site-directed mutation study uncovered that the function of AflSlt2 was dependent on the phosphorylated residues (Thr-186 and Tyr-188) within the activation loop and the phosphotransfer residue (Lys-52) within the subdomain II. Interestingly, an autophosphorylation mutant of AflSlt2 (AflSlt2R66S) displayed wild type-like phenotypes. Bringing these observations together, we propose that Slt2-MAPK pathway is involved in development, stress response, aflatoxin biosynthesis, and pathogenicity in A. flavus. This study may be useful to unveil the regulation mechanism of aflatoxin biosynthesis and provide strategy to control A. flavus contamination.
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Zheng YQ, Pan KS, Latgé JP, Andrianopoulos A, Luo H, Yan RF, Wei JY, Huang CY, Cao CW. Calcineurin A Is Essential in the Regulation of Asexual Development, Stress Responses and Pathogenesis in Talaromyces marneffei. Front Microbiol 2020; 10:3094. [PMID: 32038542 PMCID: PMC6985273 DOI: 10.3389/fmicb.2019.03094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 12/20/2019] [Indexed: 11/27/2022] Open
Abstract
Talaromyces marneffei is a common cause of infection in immunocompromised patients in Southeast Asia and Southern China. The pathogenicity of T. marneffei depends on the ability of the fungus to survive the cytotoxic processes of the host immune system and grow inside host macrophages. These mechanisms that allow T. marneffei to survive macrophage-induced death are poorly understood. In this study, we examined the role of a calcineurin homolog (cnaA) from T. marneffei during growth, morphogenesis and infection. Deletion of the cnaA gene in T. marneffei resulted in a strain with significant defects in conidiation, germination, morphogenesis, cell wall integrity, and resistance to various stressors. The ΔcnaA mutant showed a lower minimal inhibitory concentration (MIC) against caspofungin (16 μg/ml to 2 μg/ml) and micafungin (from 32 μg/ml to 4 μg/ml) compared with the wild-type. These results suggest that targeting calcineurin in combination with echinocandin treatment may be effective for life-threatening systemic T. marneffei infection. Importantly, the cnaA mutant was incapable of adapting to the macrophage environment in vitro and displayed virulence defects in a mouse model of invasive talaromycosis. For the first time, a role has been shown for cnaA in the morphology and pathogenicity of a dimorphic pathogenic filamentous fungus.
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Affiliation(s)
- Yan-Qing Zheng
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Kai-Su Pan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | | | - Alex Andrianopoulos
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hong Luo
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ru-Fan Yan
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Jin-Ying Wei
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Chun-Yang Huang
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Cun-Wei Cao
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
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Park HS, Lee SC, Cardenas ME, Heitman J. Calcium-Calmodulin-Calcineurin Signaling: A Globally Conserved Virulence Cascade in Eukaryotic Microbial Pathogens. Cell Host Microbe 2020; 26:453-462. [PMID: 31600499 DOI: 10.1016/j.chom.2019.08.004] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/29/2019] [Accepted: 08/02/2019] [Indexed: 12/19/2022]
Abstract
Calcium is an abundant intracellular ion, and calcium homeostasis plays crucial roles in several cellular processes. The calcineurin signaling cascade is one of the major pathways governed by intracellular calcium. Calcineurin, a conserved protein from yeast to humans, is a calcium-calmodulin-dependent serine-threonine-specific phosphatase that orchestrates cellular stress responses. In eukaryotic microbial pathogens, calcineurin controls essential virulence pathways, such as the ability to grow at host temperature, morphogenesis to enable invasive hyphal growth, drug tolerance and resistance, cell wall integrity, and sexual development. Therefore, the calcineurin cascade is an attractive target in drug development against eukaryotic pathogens. In the present review, we summarize and discuss the current knowledge on the roles of calcineurin in eukaryotic microbial pathogens, focusing on fungi and parasitic protists.
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Affiliation(s)
- Hee-Soo Park
- School of Food Science and Biotechnology, Institute of Agricultural Science and Technology, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Soo Chan Lee
- South Texas Center for Emerging Infectious Diseases (STCEID), Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Maria E Cardenas
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC 27710, USA.
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Participation of a MADS-box transcription factor, Mb1, in regulation of the biocontrol potential in an insect fungal pathogen. J Invertebr Pathol 2020; 170:107335. [DOI: 10.1016/j.jip.2020.107335] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 11/24/2022]
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Zhao X, Yang X, Lu Z, Wang H, He Z, Zhou G, Luo Z, Zhang Y. MADS-box transcription factor Mcm1 controls cell cycle, fungal development, cell integrity and virulence in the filamentous insect pathogenic fungus Beauveria bassiana. Environ Microbiol 2019; 21:3392-3416. [PMID: 30972885 DOI: 10.1111/1462-2920.14629] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 04/09/2019] [Indexed: 12/15/2022]
Abstract
MADS-box transcription factor Mcm1 plays crucial roles in regulating mating processes and pathogenesis in some fungi. However, its roles are varied in fungal species, and its function remains unclear in entomopathogenic fungi. Here, Mcm1 orthologue, Bbmcm1, was characterized in a filamentous entomopathogenic fungus, Beauveria bassiana. Disruption of Bbmcm1 resulted in a distinct reduction in growth with abnormal conidiogenesis, and a significant decrease in conidial viability with abnormal germination. ΔBbmcm1 displayed impaired cell integrity, with distorted cell wall structure and altered cell wall component. Abnormal cell cycle was detected in ΔBbmcm1 with longer G2 /M phase but shorter G1 /G0 and S phases in unicellular blastospores, and sparser septa in multicellular hyphae, which might be responsible for defects in development and differentiation due to the regulation of cell cycle-involved genes, as well as the corresponding cellular events-associated genes. Dramatically decreased virulence was examined in ΔBbmcm1, with impaired ability to escape haemocyte encapsulation, which was consistent with markedly reduced cuticle-degrading enzyme production by repressing their coding genes, and downregulated fungal effector protein-coding genes, suggesting a novel role of Mcm1 in interaction with host insect. These data indicate that Mcm1 is a crucial regulator of development, cell integrity, cell cycle and virulence in insect fungal pathogens.
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Affiliation(s)
- Xin Zhao
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Xingju Yang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Zhuoyue Lu
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Huifang Wang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Zhangjiang He
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Guangyan Zhou
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Zhibing Luo
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
| | - Yongjun Zhang
- Biotechnology Research Center, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Academy of Agricultural Sciences, Southwest University, Chongqing, 400715, People's Republic of China
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Huang S, Keyhani NO, Zhao X, Zhang Y. The Thm1 Zn(II)2Cys6transcription factor contributes to heat, membrane integrity and virulence in the insect pathogenic fungusBeauveria bassiana. Environ Microbiol 2019; 21:3153-3171. [DOI: 10.1111/1462-2920.14718] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 01/08/2023]
Affiliation(s)
- Shuaishuai Huang
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
- Department of Microbiology and Cell ScienceUniversity of Florida Gainesville Florida 32611 USA
| | - Nemat O. Keyhani
- Department of Microbiology and Cell ScienceUniversity of Florida Gainesville Florida 32611 USA
| | - Xin Zhao
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
| | - Yongjun Zhang
- Biotechnology Research Center, Academy of Agricultural Sciences, State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest UniversitySouthwest University Chongqing 400715 P. R. China
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Zhou Q, Shao Y, Chen A, Li W, Wang J, Wang Y. In vivo transcriptomic analysis of Beauveria bassiana reveals differences in infection strategies in Galleria mellonella and Plutella xylostella. PEST MANAGEMENT SCIENCE 2019; 75:1443-1452. [PMID: 30443979 DOI: 10.1002/ps.5266] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 11/01/2018] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Insect pests have evolved various defense mechanisms to combat fungal infection, and fungi have developed multiple strategies to overcome the immune defense responses of insects. However, transcriptomic analysis of fungal strategies for infecting different pests has not been reported. RESULTS Transcriptomic profiling of Beauveria bassiana was performed at 12, 24 and 48 h after infecting Galleria mellonella and Plutella xylostella, and 540, 847 and 932 differentially expressed genes were detected, respectively. Functional categorization showed that most of these genes are involved in the ribosome, nitrogen metabolism and oxidative phosphorylation pathways. Thirty-one differentially expressed virulence genes (including genes involved in adhesion, degradation, host colonization and killing, and secondary metabolism) were found, suggesting that different molecular mechanisms were used by the fungus during the infection of different pests, which was further confirmed by disrupting creA and fkh2. Virulence assay results showed that ΔcreA and Δfkh2 strains of B. bassiana had distinct fold changes in their 50% lethal time (LT50 ) values (compared with the control stains) during infection of G. mellonella (ΔcreA: 1.38-fold > Δfkh2: 1.18-fold) and P. xylostella (ΔcreA: 1.44-fold < Δfkh2: 2.25-fold). creA was expressed at higher levels during the infection of G. mellonella compared with P. xylostella, whereas fkh2 showed the opposite expression pattern, demonstrating that creA and Fkh2 have different roles in B. bassiana during the infection of G. mellonella and P. xylostella. CONCLUSION These findings demonstrate that B. bassiana regulates different genes to infect different insects, advancing knowledge of the molecular mechanisms of Beauveria-pest interactions. © 2018 Society of Chemical Industry.
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Affiliation(s)
- Qiumei Zhou
- Experimental Center of Clinical Research, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Ying Shao
- Jiangsu Key Construction Laboratory of Food Resource Development and Quality Safe, Xuzhou University of Technology, Xuzhou, China
| | - Anhui Chen
- Jiangsu Key Construction Laboratory of Food Resource Development and Quality Safe, Xuzhou University of Technology, Xuzhou, China
| | - Wanzhen Li
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Engineering Technology Research Center of Microbial Fermentation Anhui Province, Anhui Polytechnic University, Wuhu, China
| | - Jiuxiang Wang
- Experimental Center of Clinical Research, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Yulong Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
- Key Laboratory of Crop Quality Improvement of Anhui Province/Crop Research Institute, Anhui Academy of Agricultural Sciences, Hefei, China
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Zhen Z, Xing X, Xie M, Yang L, Yang X, Zheng Y, Chen Y, Ma N, Li Q, Zhang KQ, Yang J. MAP kinase Slt2 orthologs play similar roles in conidiation, trap formation, and pathogenicity in two nematode-trapping fungi. Fungal Genet Biol 2018; 116:42-50. [PMID: 29702229 DOI: 10.1016/j.fgb.2018.04.011] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 11/29/2022]
Abstract
Mitogen-activated protein (MAP) kinase Slt2 is a key player in the cell-wall integrity pathway of budding yeast. In this study, we functionally characterized Slt2 orthologs AoSlt2 and MhSlt2 from the nematode-trapping fungi Arthrobotrys oligospora and Monacrosporium haptotylum, respectively. We found that disruption of AoSlt2 and MhSlt2 led to reduced mycelial growth, increased sensitivity to environmental stresses such as sodium dodecyl sulfate, Congo red, and H2O2, and an inability to produce conidia and nematode-trapping structures. Real-time polymerase chain reaction-based analyses showed that the transcription of sporulation-related (AbaA, Sep2, and MedA) and cell wall synthesis-related (Chs, Glu, and Gfpa) genes was down-regulated in the mutants compared with the wild-type strains. Moreover, the mutant strains showed reduced extracellular proteolytic activity and decreased transcription of three homologous serine protease-encoding genes. These results show for the first time that MAP kinase Slt2 orthologs play similar roles in regulating mycelial growth, conidiation, trap formation, stress resistance, and pathogenicity in the divergent nematode-trapping fungal species A. oligospora and M. haptotylum.
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Affiliation(s)
- Zhengyi Zhen
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Xinjing Xing
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Meihua Xie
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Le Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Xuewei Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Yaqing Zheng
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Yuanli Chen
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Ni Ma
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Qing Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China; School of Life Sciences, Yunnan University, Kunming 650091, PR China
| | - Jinkui Yang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Yunnan University, Kunming 650091, PR China; Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan University, Kunming 650091, PR China; School of Life Sciences, Yunnan University, Kunming 650091, PR China.
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Wang Z, Zhou Q, Li Y, Qiao L, Pang Q, Huang B. iTRAQ-based quantitative proteomic analysis of conidia and mycelium in the filamentous fungus Metarhizium robertsii. Fungal Biol 2018; 122:651-658. [PMID: 29880200 DOI: 10.1016/j.funbio.2018.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 01/10/2023]
Abstract
Metarhizium robertsii is widely applied in biological control via conidia application. To clarify the proteomic differences between conidia and mycelia and explore the underlying mechanisms of conidia as a unit responsible for dispersal and environmental stress, we carried out an iTRAQ (isobaric tags for relative and absolute quantitation)-based quantitative proteomic analysis for two developmental stages from M. robertsii. A total of 2052 proteins were detected, and 90 showed differential protein abundance between the conidia and mycelia. These 90 proteins were primarily associated with stress resistance, amino acid and protein metabolism, and energy metabolism. Further bioinformatics analysis showed that these proteins could be mapped to 52 pathways, five of which were significantly enriched after mapping to KEGG pathways. Interestingly, many proteins involved in the significantly enriched pathway of peroxisome, biosynthesis of secondary metabolites and glyoxylate and dicarboxylate metabolism, including catalase, peroxisomal membrane anchor protein, formate dehydrogenase and isocitrate lyase, were identified with higher abundance in conidia. The results deepened our understanding of the conidia proteome in M. robertsii and provide a basis for further exploration for improving the efficiency of the fungi as biocontrol agents.
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Affiliation(s)
- Zhangxun Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Quan Zhou
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Yuandong Li
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China; School of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Lintao Qiao
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Qi Pang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China.
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Moonjely S, Keyhani NO, Bidochka MJ. Hydrophobins contribute to root colonization and stress responses in the rhizosphere-competent insect pathogenic fungus Beauveria bassiana. MICROBIOLOGY-SGM 2018. [PMID: 29517481 DOI: 10.1099/mic.0.000644] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The hyd1/hyd2 hydrophobins are important constituents of the conidial cell wall of the insect pathogenic fungus Beauveria bassiana. This fungus can also form intimate associations with several plant species. Here, we show that inactivation of two Class I hydrophobin genes, hyd1 or hyd2, significantly decreases the interaction of B. bassiana with bean roots. Curiously, the ∆hyd1/∆hyd2 double mutant was less impaired in root association than Δhyd1 or Δhyd2. Loss of hyd genes affected growth rate, conidiation ability and oosporein production. Expression patterns for genes involved in conidiation, cell wall integrity, insect virulence, signal transduction, adhesion, hydrophobicity and oosporein production were screened in the deletion mutants grown in different conditions. Repression of the major MAP-Kinase signal transduction pathways (Slt2 MAPK pathway) was observed that was more pronounced in the single versus double hyd mutants under certain conditions. The ∆hyd1/∆hyd2 double mutant showed up-regulation of the Hog1 MAPK and the Msn2 transcription factor under certain conditions when compared to the wild-type or single hyd mutants. The expression of the bad2 adhesin and the oosporein polyketide synthase 9 gene was severely reduced in all of the mutants. On the other hand, fewer changes were observed in the expression of key conidiation and cell wall integrity genes in hyd mutants compared to wild-type. Taken together, the data from this study indicated pleiotropic consequences of deletion of hyd1 and hyd2 on signalling and stress pathways as well as the ability of the fungus to form stable associations with plant roots.
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Affiliation(s)
- Soumya Moonjely
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Michael J Bidochka
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
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He Z, Zhao X, Lu Z, Wang H, Liu P, Zeng F, Zhang Y. Comparative transcriptome and gene co-expression network analysis reveal genes and signaling pathways adaptively responsive to varied adverse stresses in the insect fungal pathogen, Beauveria bassiana. J Invertebr Pathol 2018; 151:169-181. [DOI: 10.1016/j.jip.2017.12.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 12/07/2017] [Accepted: 12/15/2017] [Indexed: 11/27/2022]
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Wang JJ, Bai WW, Zhou W, Liu J, Chen J, Liu XY, Xiang TT, Liu RH, Wang WH, Zhang BL, Wan YJ. Transcriptomic analysis of two Beauveria bassiana strains grown on cuticle extracts of the silkworm uncovers their different metabolic response at early infection stage. J Invertebr Pathol 2017; 145:45-54. [DOI: 10.1016/j.jip.2017.03.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/17/2017] [Accepted: 03/25/2017] [Indexed: 10/19/2022]
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Gao T, Wang Z, Huang Y, Keyhani NO, Huang Z. Lack of resistance development in Bemisia tabaci to Isaria fumosorosea after multiple generations of selection. Sci Rep 2017; 7:42727. [PMID: 28230074 PMCID: PMC5322360 DOI: 10.1038/srep42727] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/12/2017] [Indexed: 01/21/2023] Open
Abstract
The emergence of insecticide resistant insect pests is of significant concern worldwide. The whitefly, Bemisia tabaci, is an important agricultural pest and has shown incredible resilience developing resistance to a number of chemical pesticides. Entomopathogenic fungi such as Isaria fumosorosea offer an attractive alternative to chemical pesticides for insect control, and this fungus has been shown to be an effective pathogen of B. tabaci. Little is known concerning the potential for the development of resistance to I. fumosorosea by B. tabaci. Five generations of successive survivors of B. tabaci infected by I. fumosorosea were assayed with I. fumosorosea. No significant differences in susceptibility to I. fumosorosea, number of ovarioles, or ovipostioning were seen between any of the generations tested. Effects of I. fumosorosea and cell-free ethyl acetate fractions derived from the fungus on the B. tabaci fat body, ovary, and vitellogenin were also investigated. These data revealed significant deformation and degradation of ovary tissues and associated vitellogenin by the fungal mycelium as well as by cell-free ethyl acetate fungal extracts. These data indicate the lack of the emergence of resistance to I. fumosorosea under the conditions tested and demonstrate invasion of the insect reproductive tissues during fungal infection.
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Affiliation(s)
- Tianni Gao
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Zhaolei Wang
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Yü Huang
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Bldg. 981, Museum Rd., Gainesville, FL32611, USA
| | - Zhen Huang
- Department of Entomology, College of Agriculture, South China Agricultural University, Guangzhou, 510642, China.,Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Bldg. 981, Museum Rd., Gainesville, FL32611, USA
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Zeng FS, Menardo F, Xue MF, Zhang XJ, Gong SJ, Yang LJ, Shi WQ, Yu DZ. Transcriptome Analyses Shed New Insights into Primary Metabolism and Regulation of Blumeria graminis f. sp. tritici during Conidiation. FRONTIERS IN PLANT SCIENCE 2017; 8:1146. [PMID: 28713408 PMCID: PMC5492466 DOI: 10.3389/fpls.2017.01146] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 06/15/2017] [Indexed: 05/04/2023]
Abstract
Conidia of the obligate biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt) play a vital role in its survival and rapid dispersal. However, little is known about the genetic basis for its asexual reproduction. To uncover the primary metabolic and regulatory events during conidiation, we sequenced the transcriptome of Bgt epiphytic structures at 3 (vegetative hyphae growth), 4 (foot cells initiation), and 5 (conidiophore erection) days post-inoculation (dpi). RNA-seq analyses identified 556 and 404 (combined 685) differentially expressed genes (DEGs) at 4 and 5 dpi compared with their expression levels at 3 dpi, respectively. We found that several genes involved in the conversion from a variety of sugars to glucose, glycolysis, the tricarboxylic acid cycle (TAC), the electron transport chain (ETC), and unsaturated fatty acid oxidation were activated during conidiation, suggesting that more energy supply is required during this process. Moreover, we found that glucose was converted into glycogen, which was accumulated in developing conidiophores, indicating that it could be the primary energy storage molecule in Bgt conidia. Clustering for the expression profiles of 91 regulatory genes showed that calcium (Ca2+), H2O2, and phosphoinositide (PIP) signaling were involved in Bgt conidiation. Furthermore, a strong accumulation of H2O2 in developing conidiophores was detected. Application of EGTA, a Ca2+ chelator, and trifluoperazine dihydrochloride (TFP), a calmodulin (CaM) antagonist, markedly suppressed the generation of H2O2, affected foot cell and conidiophore development and reduced conidia production significantly. These results suggest that Ca2+ and H2O2 signaling play important roles in conidiogenesis and a crosslink between them is present. In addition to some conidiation-related orthologs known in other fungi, such as the velvet complex components, we identified several other novel B. graminis-specific genes that have not been previously found to be implicated in fungal conidiation, reflecting a unique molecular mechanism underlying asexual development of cereal powdery mildews.
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Affiliation(s)
- Fan-Song Zeng
- College of Life Science, Wuhan UniversityWuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Fabrizio Menardo
- Institute of Plant and Microbial Biology, University of ZürichZürich, Switzerland
| | - Min-Feng Xue
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Xue-Jiang Zhang
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Shuang-Jun Gong
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Li-Jun Yang
- College of Life Science, Wuhan UniversityWuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Wen-Qi Shi
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
| | - Da-Zhao Yu
- College of Life Science, Wuhan UniversityWuhan, China
- Key Laboratory of Integrated Pest Management on Crops in Central China, Ministry of AgricultureWuhan, China
- Institute of Plant Protection and Soil Science, Hubei Academy of Agricultural SciencesWuhan, China
- *Correspondence: Da-Zhao Yu,
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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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