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Rzechonek DA, Szczepańczyk M, Mirończuk AM. Mutation in yl-HOG1 represses the filament-to-yeast transition in the dimorphic yeast Yarrowia lipolytica. Microb Cell Fact 2023; 22:155. [PMID: 37582747 PMCID: PMC10428635 DOI: 10.1186/s12934-023-02161-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/29/2023] [Indexed: 08/17/2023] Open
Abstract
BACKGROUND Yarrowia lipolytica is a dimorphic fungus, which switches from yeast to filament form in response to environmental conditions. For industrial purposes it is important to lock cells in the yeast or filamentous form depending on the fermentation process. yl-Hog1 kinase is a key component of the HOG signaling pathway, responsible for activating the osmotic stress response. Additionally, deletion of yl-Hog1 leads to increased filamentation in Yarrowia lipolytica, but causes significant sensitivity to osmotic stress induced by a high concentration of a carbon source. RESULTS In this study, we tested the effect of point mutations on the function of yl-Hog1 protein kinase. The targets of modification were the phosphorylation sites (T171A-Y173A) and the active center (K49R). Introduction of the variant HOG1-49 into the hog1∆ strain partially improved growth under osmotic stress, but did not recover the yeast-like shape of the cells. The HOG1-171/173 variant was not functional, and its introduction further weakened the growth of hog1∆ strains in hyperosmotic conditions. To verify a genetic modification in filament form, we developed a new system based on green fluorescent protein (GFP) for easier screening of proper mutants. CONCLUSIONS These results provide new insights into the functions of yl-Hog1 protein in dimorphic transition and constitute a good starting point for further genetic modification of Y. lipolytica in filament form.
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Affiliation(s)
- Dorota A Rzechonek
- Laboratory for Biosustainability, Institute of Environmental Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Mateusz Szczepańczyk
- Laboratory for Biosustainability, Institute of Environmental Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Aleksandra M Mirończuk
- Laboratory for Biosustainability, Institute of Environmental Biology, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.
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Lesage J, Timoumi A, Cenard S, Lombard E, Lee HLT, Guillouet SE, Gorret N. Accelerostat study in conventional and microfluidic bioreactors to assess the key role of residual glucose in the dimorphic transition of Yarrowia lipolytica in response to environmental stimuli. N Biotechnol 2021; 64:37-45. [PMID: 34058397 DOI: 10.1016/j.nbt.2021.05.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 05/12/2021] [Accepted: 05/16/2021] [Indexed: 11/19/2022]
Abstract
Yarrowia lipolytica, with a diverse array of biotechnological applications, is able to grow as ovoid yeasts or filamentous hyphae depending on environmental conditions. This study has explored the relationship between residual glucose levels and dimorphism in Y. lipolytica. Under pH stress conditions, the morphological and physiological characteristics of the yeast were examined during well-controlled accelerostat cultures using both a 1 L-laboratory scale and a 1 mL-microfluidic bioreactor. The accelerostat mode, via a smooth increase of dilution rate (D), enabled the cell growth rate to increase gradually up to the cell wash-out (D ≥μmax of the strain), which was accompanied by a progressive increase in residual glucose concentration. The results showed that Y. lipolytica maintained an ovoid morphology when residual glucose concentration was below a threshold value of around 0.35-0.37 mg L-1. Transitions towards more elongated forms were triggered at this threshold and progressively intensified with the increase in residual glucose levels. The effect of cAMP on the dimorphic transition was assessed by the exogenous addition of cAMP and the quantification of its intracellular levels during the accelerostat. cAMP has been reported to be an important mediator of environmental stimuli that inhibit filamentous growth in Y. lipolytica by activating the cAMP-PKA regulatory pathway. It was confirmed that the exogenous addition of cAMP inhibited the mycelial morphology of Y. lipolytica, even with glucose concentrations exceeding the threshold level. The results suggest that dimorphic responses in Y. lipolytica are regulated by sugar signaling pathways, most likely via the cAMP-PKA dependent pathway.
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Affiliation(s)
- Julie Lesage
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France
| | - Asma Timoumi
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France
| | - Stéphanie Cenard
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France
| | - Eric Lombard
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France
| | - Harry L T Lee
- Erbi Bio, Inc, 325 New Boston Stress, Unit 6, Woburn, MA, 01801, USA
| | - Stéphane E Guillouet
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France
| | - Nathalie Gorret
- Toulouse Biotechnology Institute (TBI), Université de Toulouse, CNRS, INRA, INSA, 135 Avenue de Rangueil. 35077, Toulouse Cedex, France.
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Wang Y, Tang LJ, Peng X, Zhang ZB, Yang HL, Yan RM, Zhu D. Transcriptome analysis of the dimorphic transition induced by pH change and lipid biosynthesis in Trichosporon cutaneum. J Ind Microbiol Biotechnol 2019; 47:49-61. [PMID: 31834585 DOI: 10.1007/s10295-019-02244-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 10/26/2019] [Indexed: 11/27/2022]
Abstract
Trichosporon cutaneum, a dimorphic oleaginous yeast, has immense biotechnological potential, which can use lignocellulose hydrolysates to accumulate lipids. Our preliminary studies on its dimorphic transition suggested that pH can significantly induce its morphogenesis. However, researches on dimorphic transition correlating with lipid biosynthesis in oleaginous yeasts are still limited. In this study, the unicellular yeast cells induced under pH 6.0-7.0 shake flask cultures resulted in 54.32% lipid content and 21.75 g/L dry cell weight (DCW), so lipid production was over threefold than that in hypha cells induced by acidic condition (pH 3.0-4.0). Furthermore, in bioreactor batch cultivation, the DCW and lipid content in unicellular yeast cells can reach 21.94 g/L and 58.72%, respectively, both of which were also more than twofold than that in hypha cells. Moreover, the activities of isocitrate dehydrogenase (IDH), malic enzyme (MAE), isocitrate lyase (ICL) and ATP citrate lyase (ACL) in unicellular cells were all higher than in the hyphal cells. In the meanwhile, the transcriptome data showed that the genes related to fatty acid biosynthesis, carbon metabolism and encoded Rim101 and cAMP-PKA signaling transduction pathways were significantly up-regulated in unicellular cells, which may play an important role in enhancing the lipid accumulation. In conclusion, our results provided insightful information focused on the molecular mechanism of dimorphic transition and process optimization for enhancing lipid accumulation in T. cutaneum.
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Affiliation(s)
- Ya Wang
- College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai, 200240, China
| | - Li Juan Tang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Xuan Peng
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Zhi Bin Zhang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Hui Lin Yang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Ri Ming Yan
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China
| | - Du Zhu
- College of Life Sciences, Jiangxi Science and Technology Normal University, Nanchang, 330013, China.
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, Jiangxi Normal University, Nanchang, 330022, China.
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Zhang Y, Wu M, Ge Q, Yang M, Xia W, Cui H, Yu X, Zhang S, Ye Z. Cloning and disruption of the UeArginase in Ustilago esculenta: evidence for a role of arginine in its dimorphic transition. BMC Microbiol 2019; 19:208. [PMID: 31488050 PMCID: PMC6727352 DOI: 10.1186/s12866-019-1588-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 08/29/2019] [Indexed: 11/21/2022] Open
Abstract
Background Ustilago esculenta, a typical dimorphic fungus could infect Zizania latifolia and induce host stem swollen to form an edible vegetable called Jiaobai in China. The strains differentiation especially in the mating ability and pathogenicity is closely related to different phenotypes of Jiaobai formed in the fields. Dimorphic switching, a tightly regulated processes, is essential for the pathogenetic development of dimorphic fungi. In responses to environment cues, dimorphic switching can be activated through two conserved cell signaling pathways-PKA and MAPK pathways. Previous study indicated that exogenous arginine could induce hyphal formation in several dimorphic fungi through hydrolysis by arginase, but inhibit the dimorphic transition of U. esculenta. We conducted this study to reveal the function of arginine on dimorphic transition of U. esculenta. Results In this study, we found that arginine, but not its anabolites, could slow down the dimorphic transition of U. esculenta proportionally to the concentration of arginine. Besides, UeArginase, predicated coding arginase in U. esculenta was cloned and characterized. UeArginase mutants could actually increase the content of endogenous arginine, and slow down the dimorphic transition on either nutritious rich or poor medium. Either adding exogenous arginine or UeArginase deletion lead to down regulated expressions of UePkaC, UePrf1, mfa1.2, mfa2.1, pra1 and pra2, along with an increased content of arginine during mating process. Conclusion Results of this study indicated a direct role of arginine itself on the inhibition of dimorphic transition of U. esculenta, independent of its hydrolysis by UeArginase. Electronic supplementary material The online version of this article (10.1186/s12866-019-1588-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yafen Zhang
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Min Wu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Qianwen Ge
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Mengfei Yang
- Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, China
| | - Wenqiang Xia
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Haifeng Cui
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Xiaoping Yu
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Shangfa Zhang
- Jinhua Academy of Agricultural Sciences, Jinhua, Zhejiang, China
| | - Zihong Ye
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou, 310018, Zhejiang, China.
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Wang Y, Yan R, Tang L, Zhu L, Zhu D, Bai F. Dimorphism of Trichosporon cutaneum and impact on its lipid production. Biotechnol Biofuels 2019; 12:203. [PMID: 31485269 PMCID: PMC6714079 DOI: 10.1186/s13068-019-1543-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 08/10/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Compared to the oleaginous yeast Yarrowia lipolytica, Trichosporon cutaneum can metabolize pentose sugars more efficiently, and in the meantime is more tolerant to inhibitors, which is suitable for lipid production from lignocellulosic biomass. However, this species experiences dimorphic transition between yeast-form cells and hyphae during submerged fermentation, which consequently affects the rheology and mass transfer performance of the fermentation broth and its lipid production. RESULTS The strain T. cutaneum B3 was cultured with medium composed of yeast extract, glucose and basic minerals. The experimental results indicated that yeast-form morphology was developed when yeast extract was supplemented at 1 g/L, but hyphae were observed when yeast extract supplementation was increased to 3 g/L and 5 g/L, respectively. We speculated that difference in nitrogen supply to the medium might be a major reason for the dimorphic transition, which was confirmed by the culture with media supplemented with yeast extract at 1 g/L and urea at 0.5 g/L and 1.0 g/L to maintain total nitrogen at same levels as that detected in the media with yeast extract supplemented at 3 g/L and 5 g/L. The morphological change of T. cutaneum B3 affected not only the content of intracellular lipids but also their composition, due to its impact on the rheology and oxygen mass transfer performance of the fermentation broth, and more lipids with less polyunsaturated fatty acids such as linoleic acid (C18:2) were produced by the yeast-form cells. When T. cutaneum B3 was cultured at an aeration rate of 1.5 vvm for 72 h with the medium composed of 60 g/L glucose, 3 g/L yeast extract and basic minerals, 27.1 g (dry cell weight)/L biomass was accumulated with the lipid content of 46.2%, and lipid productivity and yield were calculated to be 0.174 g/L/h and 0.21 g/g, respectively. Comparative transcriptomics analysis identified differently expressed genes for sugar metabolism and lipid synthesis as well as signal transduction for the dimorphic transition of T. cutaneum B3. CONCLUSIONS Assimilable nitrogen was validated as one of the major reasons for the dimorphic transition between yeast-form morphology and hyphae with T. cutaneum, and the yeast-form morphology was more suitable for lipid production at high content with less polyunsaturated fatty acids as feedstock for biodiesel production.
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Affiliation(s)
- Ya Wang
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai, 200240 China
| | - Riming Yan
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, School of Life Science, Jiangxi Normal University, 99 Ziyang Rd., Nanchang, 330022 China
| | - Lijuan Tang
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, School of Life Science, Jiangxi Normal University, 99 Ziyang Rd., Nanchang, 330022 China
| | - Libin Zhu
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, School of Life Science, Jiangxi Normal University, 99 Ziyang Rd., Nanchang, 330022 China
| | - Du Zhu
- School of Life Science, Jiangxi Science and Technology Normal University, 605 Fenglin Rd., Nanchang, 330013 China
- Key Laboratory of Protection and Utilization of Subtropic Plant Resources of Jiangxi Province, School of Life Science, Jiangxi Normal University, 99 Ziyang Rd., Nanchang, 330022 China
| | - Fengwu Bai
- State Key Laboratory of Microbial Metabolism & School of Life Science and Biotechnology, Shanghai Jiao Tong University, 800 Dongchuan Rd., Shanghai, 200240 China
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Wang Z, Yang J, Xin C, Xing X, Yin Y, Chen L, Song Z. Regulation of conidiation, dimorphic transition, and microsclerotia formation by MrSwi6 transcription factor in dimorphic fungus Metarhizium rileyi. World J Microbiol Biotechnol 2019; 35:46. [PMID: 30825005 DOI: 10.1007/s11274-019-2619-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 02/23/2019] [Indexed: 11/25/2022]
Abstract
Microsclerotia (MS) produced in the liquid culture of the dimorphic insect pathogen Metarhizium rileyi can be used as a mycoinsecticide. Bioinformatics analysis demonstrated that the cell cycle signaling pathway was involved in regulating MS formation. To investigate the mechanisms by which the signaling pathway is regulated, a cell cycle box binding transcription factor MrSwi6 of M. rileyi was characterized. MrSwi6 was highly expressed during periods of yeast-hypha transition and conidia and MS formation. When compared with wild-type and complemented strains, disruption of MrSwi6 significantly reduced conidia (15-36%) and MS formation (96.2%), and exhibited decreased virulence levels. Digital expression profiling revealed that genes involved in antioxidation, pigment biosynthesis, and ion transport and storage were regulated by MrSwi6 during conidia and MS development. These results confirmed the significance of MrSwi6 in dimorphic transition, conidia and MS formation, and virulence in M. rileyi.
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Affiliation(s)
- Zhongkang Wang
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Jie Yang
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Caiyan Xin
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Xiaorui Xing
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Youping Yin
- Chongqing Engineering Research Center for Fungal Insecticide, School of Life Science, Chongqing University, Chongqing, 400030, People's Republic of China
| | - Li Chen
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China
| | - Zhangyong Song
- School of Basic Medical Sciences, Southwest Medical University, Luzhou, 646000, People's Republic of China.
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Boral H, Metin B, Döğen A, Seyedmousavi S, Ilkit M. Overview of selected virulence attributes in Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, Trichophyton rubrum, and Exophiala dermatitidis. Fungal Genet Biol 2017; 111:92-107. [PMID: 29102684 DOI: 10.1016/j.fgb.2017.10.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/24/2017] [Accepted: 10/27/2017] [Indexed: 12/13/2022]
Abstract
The incidence of fungal diseases has been increasing since 1980, and is associated with excessive morbidity and mortality, particularly among immunosuppressed patients. Of the known 625 pathogenic fungal species, infections caused by the genera Aspergillus, Candida, Cryptococcus, and Trichophyton are responsible for more than 300 million estimated episodes of acute or chronic infections worldwide. In addition, a rather neglected group of opportunistic fungi known as black yeasts and their filamentous relatives cause a wide variety of recalcitrant infections in both immunocompetent and immunosuppressed hosts. This article provides an overview of selected virulence factors that are known to suppress host immunity and enhance the infectivity of these fungi.
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Affiliation(s)
- Hazal Boral
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey
| | - Banu Metin
- Department of Food Engineering, Faculty of Engineering and Natural Sciences, Istanbul Sabahattin Zaim University, Istanbul, Turkey
| | - Aylin Döğen
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Mersin, Mersin, Turkey
| | - Seyedmojtaba Seyedmousavi
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands; Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Center of Excellence for Infection Biology and Antimicrobial Pharmacology, Tehran, Iran
| | - Macit Ilkit
- Division of Mycology, Department of Microbiology, Faculty of Medicine, University of Çukurova, Adana, Turkey.
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Chu ZJ, Sun HH, Ying SH, Feng MG. Vital role for cyclophilin B (CypB) in asexual development, dimorphic transition and virulence of Beauveria bassiana. Fungal Genet Biol 2017; 105:8-15. [PMID: 28552321 DOI: 10.1016/j.fgb.2017.05.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/19/2017] [Accepted: 05/23/2017] [Indexed: 11/21/2022]
Abstract
Cyclophilin B (CypB) was previously revealed as one of many putative secretory proteins in the transcriptome of Beauveria bassiana infection to a lepidopteran pest. Here we show a main localization of CypB in hyphal cell walls and septa and its essential role in the in vitro and in vivo asexual cycles of the fungal insect pathogen. Deletion of cypB reduced colony growth by 16-42% on two rich media and 30 scant media with different carbon or nitrogen sources. The deletion mutant suffered a delayed conidiation on a standard medium and a final 47% reduction in conidial yield, accompanied with drastic transcript depression of several key genes required for conidiation and conidial maturation. The mutant conidia required 10h longer to germinate 50% at optimal 25°C than wild-type conidia. Intriguingly, cultivation of the mutant conidia in a trehalose-peptone broth mimic to insect hemolymph resulted in 83% reduction in blastospore yield but only slight decrease in biomass level, indicating severe defects in transition of hyphae to blastospores. LT50 for the deletion mutant against Galleria mellonella larvae through normal cuticle infection was prolonged to 7.4d from a wild-type estimate of 4.7d. During colony growth, additionally, the deletion mutant displayed hypersensitivity to Congo red, menadione, H2O2 and heat shock but increased tolerance to cyclosporine A and rapamycin. All of changes were restored by targeted gene complementation. Altogether, CypB takes part in sustaining normal growth, aerial conidiation, conidial germination, dimorphic transition, stress tolerance and pathogenicity in B. bassiana.
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