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Zhao Y, Zheng X, Tabima JF, Zhu S, Søndreli KL, Hundley H, Bauer D, Barry K, Zhang Y, Schmutz J, Wang Y, LeBoldus JM, Xiong Q. Secreted Effector Proteins of Poplar Leaf Spot and Stem Canker Pathogen Sphaerulina musiva Manipulate Plant Immunity and Contribute to Virulence in Diverse Ways. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:779-795. [PMID: 37551980 DOI: 10.1094/mpmi-07-23-0091-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Fungal effectors play critical roles in manipulating plant immune responses and promoting colonization. Sphaerulina musiva is a heterothallic ascomycete fungus that causes Septoria leaf spot and stem canker disease in poplar (Populus spp.) plantations. This disease can result in premature defoliation, branch and stem breakage, increased mortality, and plantation failure. However, little is known about the interaction between S. musiva and poplar. Previous work predicted 142 candidate secreted effector proteins in S. musiva (SmCSEPs), 19 of which were selected for further functional characterization in this study. SmCSEP3 induced plant cell death in Nicotiana benthamiana, while 8 out of 19 tested SmCSEPs suppressed cell death. The signal peptides of these eight SmCSEPs exhibited secretory activity in a yeast signal sequence trap assay. Confocal microscopy revealed that four of these eight SmCSEPs target both the cytoplasm and the nucleus, whereas four predominantly localize to discrete punctate structures. Pathogen challenge assays in N. benthamiana demonstrated that the transient expression of six SmCSEPs promoted Fusarium proliferatum infection. The expression of these six SmCSEP genes were induced during infection. SmCSEP2, SmCSEP13, and SmCSEP25 suppressed chitin-triggered reactive oxygen species burst and callose deposition in N. benthamiana. The candidate secreted effector proteins of S. musiva target multiple compartments in the plant cell and modulate different pattern-triggered immunity pathways. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2023.
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Affiliation(s)
- Yao Zhao
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210095, China
| | - Xinyue Zheng
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Javier F Tabima
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
- Department of Forest Engineering, Resources and Management, College of Forestry, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Sheng Zhu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Kelsey L Søndreli
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Hope Hundley
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Diane Bauer
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Kerrie Barry
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, U.S.A
| | - Yaxin Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Jeremy Schmutz
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, U.S.A
| | - Yuanchao Wang
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210095, China
| | - Jared M LeBoldus
- Department of Botany and Plant Pathology, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, U.S.A
- Department of Biology, Clark University, Worcester, MA 01610, U.S.A
| | - Qin Xiong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
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Toopaang W, Bunnak W, Srisuksam C, Wattananukit W, Tanticharoen M, Yang YL, Amnuaykanjanasin A. Microbial polyketides and their roles in insect virulence: from genomics to biological functions. Nat Prod Rep 2022; 39:2008-2029. [PMID: 35822627 DOI: 10.1039/d1np00058f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Covering: May 1966 up to January 2022Entomopathogenic microorganisms have potential for biological control of insect pests. Their main secondary metabolites include polyketides, nonribosomal peptides, and polyketide-nonribosomal peptide (PK-NRP) hybrids. Among these secondary metabolites, polyketides have mainly been studied for structural identification, pathway engineering, and for their contributions to medicine. However, little is known about the function of polyketides in insect virulence. This review focuses on the role of bacterial and fungal polyketides, as well as PK-NRP hybrids in insect infection and killing. We also discuss gene distribution and evolutional relationships among different microbial species. Further, the role of microbial polyketides and the hybrids in modulating insect-microbial symbiosis is also explored. Understanding the mechanisms of polyketides in insect pathogenesis, how compounds moderate the host-fungus interaction, and the distribution of PKS genes across different fungi and bacteria will facilitate the discovery and development of novel polyketide-derived bio-insecticides.
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Affiliation(s)
- Wachiraporn Toopaang
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120, Thailand. .,Molecular and Biological Agricultural Sciences, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taiwan.,Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan.
| | - Warapon Bunnak
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120, Thailand.
| | - Chettida Srisuksam
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120, Thailand.
| | - Wilawan Wattananukit
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120, Thailand.
| | - Morakot Tanticharoen
- School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Yu-Liang Yang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei 11529, Taiwan. .,Biotechnology Center in Southern Taiwan, Academia Sinica, Tainan 711010, Taiwan
| | - Alongkorn Amnuaykanjanasin
- National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Phahonyothin Rd., Khlong Nueng, Amphoe Khlong Luang, Pathum Thani 12120, Thailand.
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Cyclophilin BcCyp2 Regulates Infection-Related Development to Facilitate Virulence of the Gray Mold Fungus Botrytis cinerea. Int J Mol Sci 2021; 22:ijms22041694. [PMID: 33567582 PMCID: PMC7914984 DOI: 10.3390/ijms22041694] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/01/2021] [Accepted: 02/04/2021] [Indexed: 11/23/2022] Open
Abstract
Cyclophilin (Cyp) and Ca2+/calcineurin proteins are cellular components related to fungal morphogenesis and virulence; however, their roles in mediating the pathogenesis of Botrytis cinerea, the causative agent of gray mold on over 1000 plant species, remain largely unexplored. Here, we show that disruption of cyclophilin gene BcCYP2 did not impair the pathogen mycelial growth, osmotic and oxidative stress adaptation as well as cell wall integrity, but delayed conidial germination and germling development, altered conidial and sclerotial morphology, reduced infection cushion (IC) formation, sclerotial production and virulence. Exogenous cyclic adenosine monophosphate (cAMP) rescued the deficiency of IC formation of the ∆Bccyp2 mutants, and exogenous cyclosporine A (CsA), an inhibitor targeting cyclophilins, altered hyphal morphology and prevented host-cell penetration in the BcCYP2 harboring strains. Moreover, calcineurin-dependent (CND) genes are differentially expressed in strains losing BcCYP2 in the presence of CsA, suggesting that BcCyp2 functions in the upstream of cAMP- and Ca2+/calcineurin-dependent signaling pathways. Interestingly, during IC formation, expression of BcCYP2 is downregulated in a mutant losing BcJAR1, a gene encoding histone 3 lysine 4 (H3K4) demethylase that regulates fungal development and pathogenesis, in B. cinerea, implying that BcCyp2 functions under the control of BcJar1. Collectively, our findings provide new insights into cyclophilins mediating the pathogenesis of B. cinerea and potential targets for drug intervention for fungal diseases.
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The Inhibitory Effect of Validamycin A on Aspergillus flavus. Int J Microbiol 2020; 2020:3972415. [PMID: 32676114 PMCID: PMC7336217 DOI: 10.1155/2020/3972415] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 05/08/2020] [Accepted: 06/03/2020] [Indexed: 12/13/2022] Open
Abstract
Aspergillus flavus is one of the most common isolates from patients with fungal infections. Aspergillus infection is usually treated with antifungal agents, but side effects of these agents are common. Trehalase is an essential enzyme involved in fungal metabolism, and the trehalase inhibitor, validamycin A, has been used to prevent fungal infections in agricultural products. In this study, we observed that validamycin A significantly increased trehalose levels in A. flavus conidia and delayed germination, including decreased fungal adherence. In addition, validamycin A and amphotericin B showed a combinatorial effect on A. flavus ATCC204304 and clinical isolates with high minimum inhibitory concentrations (MICs) of amphotericin B using checkerboard assays. We observed that validamycin A and amphotericin B had a synergistic effect on A. flavus strains resistant to amphotericin B. The MICs in the combination of validamycin A and amphotericin B were at 0.125 μg/mL and 2 μg/mL, respectively. The FICI of validamycin A and amphotericin B of these clinical isolates was about 0.25-0.28 with synergistic effects. No drug cytotoxicity was observed in human bronchial epithelial cells treated with validamycin A using LDH-cytotoxicity assays. In conclusion, this study demonstrated that validamycin A inhibited the growth of A. flavus and delayed conidial germination. Furthermore, the combined effect of validamycin A with amphotericin B increased A. flavus killing, without significant cytotoxicity to human bronchial epithelial cells. We propose that validamycin A could potentially be used in vivo as an alternative treatment for A. flavus infections.
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Ge Q, Zhang Y, Xu Y, Bai M, Luo W, Wang B, Niu Y, Zhao Y, Li S, Weng Y, Wang Z, Qian Q, Chong K. Cyclophilin OsCYP20-2 with a novel variant integrates defense and cell elongation for chilling response in rice. THE NEW PHYTOLOGIST 2020; 225:2453-2467. [PMID: 31736073 PMCID: PMC7064896 DOI: 10.1111/nph.16324] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 10/31/2019] [Indexed: 05/20/2023]
Abstract
Coordinating stress defense and plant growth is a survival strategy for adaptation to different environments that contains a series of processes, such as, cell growth, division and differentiation. However, little is known about the coordination mechanism for protein conformation change. A cyclophilin OsCYP20-2 with a variant interacts with SLENDER RICE1 (SLR1) and OsFSD2 in the nucleus and chloroplasts, respectively, to integrate chilling tolerance and cell elongation in rice (Oryza sativa) (FSD2, Fe-superoxide dismutase 2). Mass spectrum assay showed that OsNuCYP20-2 localized at the nucleus (nuclear located OsCYP20-2) was a new variant of OsCYP20-2 that truncated 71 amino-acid residues in N-terminal. The loss-of function OsCYP20-2 mutant showed sensitivity to chilling stress with accumulation of extra reactive oxygen species (ROS). In chloroplasts, the full-length OsCYP20-2 promotes OsFSD2 forming homodimers which enhance its activity, eliminating the accumulation of ROS under chilling stress. However, the mutant had shorter epidermal cells in comparison with wild-type Hwayoung (HY). In the nucleus, OsCYP20-2 caused conformation change of SLR1 to promote its degradation for cell elongation. Our data reveal a cyclophilin with a variant with dual-localization in chloroplasts and the nucleus, which mediate chilling tolerance and cell elongation.
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Affiliation(s)
- Qiang Ge
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
- University of Chinese Academy of SciencesBeijing100049China
| | - Yuanyuan Zhang
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
| | - Yunyuan Xu
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
- Innovation Academy for Seed DesignChinese Academy of SciencesBeijing100101China
| | - Mingyi Bai
- The Key Laboratory of Plant Cell Engineering and Germplasm InnovationMinistry of EducationSchool of Life SciencesShandong UniversityJinan250100China
| | - Wei Luo
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
| | - Bo Wang
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
- University of Chinese Academy of SciencesBeijing100049China
| | - Yuda Niu
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
| | - Yuan Zhao
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
- University of Chinese Academy of SciencesBeijing100049China
| | - Shanshan Li
- Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
| | - Yuxiang Weng
- Laboratory of Soft Matter PhysicsInstitute of PhysicsChinese Academy of SciencesBeijing100190China
| | - Zhiyong Wang
- Department of Plant BiologyCarnegie Institution for ScienceStanfordCA94305USA
| | - Qian Qian
- State Key Laboratory of Rice BiologyChina National Rice Research InstituteChinese Academy of Agricultural SciencesHangzhou310006China
| | - Kang Chong
- Key Laboratory of Plant Molecular PhysiologyInstitute of BotanyChinese Academy of SciencesBeijing100093China
- University of Chinese Academy of SciencesBeijing100049China
- Innovation Academy for Seed DesignChinese Academy of SciencesBeijing100101China
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Li Y, Ren H, Zhao Y, Sun J, Fan Y, Jin D, Pei Y. Characterization of three FK506-binding proteins in the entomopathogenic fungus Beauveria bassiana. J Invertebr Pathol 2020; 171:107334. [PMID: 32006551 DOI: 10.1016/j.jip.2020.107334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/26/2020] [Accepted: 01/28/2020] [Indexed: 10/25/2022]
Abstract
FK506 binding proteins (FKBPs) participate in regulation of diverse biological processes. However, the role of these proteins in insect-pathogenic fungi is far from well understood. To investigate the functions of FKBPs in Beauveria bassiana, a widely used entomopathogenic fungus for control of insect pests, we identify three putative FKBP genes, Bbfkbp12, Bbfkbp15, and Bbfkbp50, in the fungus. Gene-disruption experiments show that loss of Bbfkbp12 results in a significant increase of resistance of B. bassiana against the immunosuppressive compounds FK506 and rapamycin, while loss of Bbfkbp50 leads to the resistance to the ergosterol synthesis inhibitor lovastatin. Transcription assays of calcineurin (CaN)- and mTOR (mammalian target of rapamycin)-downstream target genes confirm that BbFKBP12 is the target of both FK506 and rapamycin, associated with CaN- and mTOR-signal pathways in B. bassiana. GFP-tagging of the proteins shows that BbFKBP12 and BbFKBP15 localize in cytoplasm while BbFKBP50 in nucleus. Our results provide useful information for the study of functions of CaN- and mTOR-mediated signaling, and ergosterol synthesis in the entomopathogenic fungi.
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Affiliation(s)
- Yujie Li
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Hui Ren
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Yutao Zhao
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Jiyuan Sun
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Yanhua Fan
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Dan Jin
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China
| | - Yan Pei
- Biotechnology Research Center, Southwest University, Beibei, Chongqing 400716, China.
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Guo H, Wang H, Keyhani NO, Xia Y, Peng G. Disruption of an adenylate-forming reductase required for conidiation, increases virulence of the insect pathogenic fungus Metarhizium acridum by enhancing cuticle invasion. PEST MANAGEMENT SCIENCE 2020; 76:758-768. [PMID: 31392798 DOI: 10.1002/ps.5576] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 07/27/2019] [Accepted: 08/05/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Metarhizium acridum, is a specific acridid pathogen developed for use against the migratory locust (Locusta migratoria manilensis). Adenylate-forming reductases (AFRs) include enzymes that are involved in natural product biosynthesis. Here, we genetically characterize the functions of a class IV AFR in M. acridum (MaAfrIV ) on fungal development and virulence. RESULTS Gene expression analyses indicated MaAfrIV was induced on locust wings early during the infection process. Surprisingly, loss of MaAfrIV increased virulence (25.20% decrease in the median lethal time) against the locust in topical bioassays but was no different than the wild type when the cuticle was bypassed by direct infection of conidia into the insect hemocoel. Virulence markers including protease (Pr1) expression and appressorial turgor pressure were higher in the mutant than the parent strain. No difference was seen in the expression of host immune genes (Toll pathway) or in polyphenol oxidase (PPO) activity in locusts infected by the ΔMaAfrIV or wild type strains. However, the ΔMaAfrIV strain was unable to successfully sporulate on dead cadavers. CONCLUSION Disruption of MaAfrIV increased fungal virulence by promoting insect cuticle invasion without altering host immune response or fungal immune evasion. Although loss of MaAfrIV conferred an apparent benefit to the fungus in terms of enhanced virulence, a significant trade-off was seen in the inability of the fungus to sporulate on the cadaver. As conidiation on the cadaver is essential for subsequent propagation in the environment, loss of MaAfrIV can reduce the engineering strains survivability in the field and improve the safety. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Haoyu Guo
- Chongqing Engineering Research Center for Fungal Insecticides and Key Lab of Functional Gene and Regulation Technology under Chongqing Municipal Education Commission, School of Life Sciences, Chongqing University, Chongqing, China
| | - Hongjuan Wang
- Chongqing Engineering Research Center for Fungal Insecticides and Key Lab of Functional Gene and Regulation Technology under Chongqing Municipal Education Commission, School of Life Sciences, Chongqing University, Chongqing, China
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, USA
| | - Yuxian Xia
- Chongqing Engineering Research Center for Fungal Insecticides and Key Lab of Functional Gene and Regulation Technology under Chongqing Municipal Education Commission, School of Life Sciences, Chongqing University, Chongqing, China
| | - Guoxiong Peng
- Chongqing Engineering Research Center for Fungal Insecticides and Key Lab of Functional Gene and Regulation Technology under Chongqing Municipal Education Commission, School of Life Sciences, Chongqing University, Chongqing, China
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Yang X, Feng P, Yin Y, Bushley K, Spatafora JW, Wang C. Cyclosporine Biosynthesis in Tolypocladium inflatum Benefits Fungal Adaptation to the Environment. mBio 2018; 9:e01211-18. [PMID: 30279281 PMCID: PMC6168864 DOI: 10.1128/mbio.01211-18] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 08/22/2018] [Indexed: 12/19/2022] Open
Abstract
The cycloundecapeptide cyclosporin A (CsA) was first isolated from the insect-pathogenic fungus Tolypocladium inflatum for its antifungal activity and later developed as an immunosuppressant drug. However, the full biosynthetic mechanism of CsA remains unknown and has puzzled researchers for decades. In this study, the biosynthetic gene cluster is suggested to include 12 genes encoding enzymes, including the nonribosomal peptide synthetase (NRPS) (SimA) responsible for assembling the 11 amino acid substrates of cyclosporine and a polyketide synthase (PKS) (SimG) to mediate the production of the unusual amino acid (4R)-4-[(E)-2-butenyl]-4-methyl-l-threonine (Bmt). Individual deletion of 10 genes, isolation of intermediates, and substrate feeding experiments show that Bmt is biosynthesized by three enzymes, including SimG, SimI, and SimJ. The substrate d-alanine is catalyzed from l-alanine by alanine racemase SimB. Gene cluster transcription is regulated by a putative basic leucine zipper (bZIP)-type protein encoded by the cluster gene SimL We also found that the cluster cyclophilin (SimC) and transporter (SimD) genes contribute to the tolerance of CsA in the CsA-producing fungus. We also found that cyclosporine production could enable the fungus to outcompete other fungi during cocultivation tests. Deletion of the CsA biosynthetic genes also impaired fungal virulence against insect hosts. Taking all the data together, in addition to proposing a biosynthetic pathway of cyclosporines, the results of this study suggest that CsA produced by this fungus might play important ecological roles in fungal environment interactions.IMPORTANCE The cyclopeptide cyclosporin A was first isolated from the filamentous fungus Tolypocladium inflatum showing antifungal activity and was later developed as an immunosuppressant drug. We report the biosynthetic mechanism of cyclosporines that are mediated by a cluster of genes encoding NRPS and PKS controlled by a bZIP-type transcriptional regulator. The two unusual amino acids Bmt and d-Ala are produced by the PKS pathway and alanine racemase, respectively. The cyclophilin and transporter genes jointly contribute to fungal self-protection against cyclosporines. Cyclosporine confers on T. inflatum the abilities to outcompete other fungi in competitive interactions and to facilitate fungal infection of insect hosts, which therefore benefits fungal adaptations to different environments.
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Affiliation(s)
- Xiuqing Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Peng Feng
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Ying Yin
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Kathryn Bushley
- Department of Plant Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Joseph W Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA
| | - Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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Zeng G, Zhang P, Zhang Q, Zhao H, Li Z, Zhang X, Wang C, Yin WB, Fang W. Duplication of a Pks gene cluster and subsequent functional diversification facilitate environmental adaptation in Metarhizium species. PLoS Genet 2018; 14:e1007472. [PMID: 29958281 PMCID: PMC6042797 DOI: 10.1371/journal.pgen.1007472] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 07/12/2018] [Accepted: 06/06/2018] [Indexed: 12/15/2022] Open
Abstract
The ecological importance of the duplication and diversification of gene clusters that synthesize secondary metabolites in fungi remains poorly understood. Here, we demonstrated that the duplication and subsequent diversification of a gene cluster produced two polyketide synthase gene clusters in the cosmopolitan fungal genus Metarhizium. Diversification occurred in the promoter regions and the exon-intron structures of the two Pks paralogs (Pks1 and Pks2). These two Pks genes have distinct expression patterns, with Pks1 highly expressed during conidiation and Pks2 highly expressed during infection. Different upstream signaling pathways were found to regulate the two Pks genes. Pks1 is positively regulated by Hog1-MAPK, Slt2-MAPK and Mr-OPY2, while Pks2 is positively regulated by Fus3-MAPK and negatively regulated by Mr-OPY2. Pks1 and Pks2 have been subjected to positive selection and synthesize different secondary metabolites. PKS1 is involved in synthesis of an anthraquinone derivative, and contributes to conidial pigmentation, which plays an important role in fungal tolerance to UV radiation and extreme temperatures. Disruption of the Pks2 gene delayed formation of infectious structures and increased the time taken to kill insects, indicating that Pks2 contributes to pathogenesis. Thus, the duplication of a Pks gene cluster and its subsequent functional diversification has increased the adaptive flexibility of Metarhizium species.
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Affiliation(s)
- Guohong Zeng
- Institute of Microbiology, Zhejiang University, Hangzhou, China
| | - Peng Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | | | - Hong Zhao
- Institute of Microbiology, Zhejiang University, Hangzhou, China
| | - Zixin Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Xing Zhang
- Institute of Microbiology, Zhejiang University, Hangzhou, China
| | - Chengshu Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People’s Republic of China
| | - Weiguo Fang
- Institute of Microbiology, Zhejiang University, Hangzhou, China
- * E-mail:
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Abstract
Heat tolerance is well known to be key to fungal survival in many habitats, but our mechanistic understanding of how organisms adapt to heat stress is still incomplete. Using Metarhizium robertsii, an emerging model organism for assessing evolutionary processes, we report that pyruvate is in the vanguard of molecules that scavenge heat-induced reactive oxygen species (ROS). We show that, as well as inducing a rapid burst of ROS production, heat stress also downregulates genes for pyruvate consumption. The accumulating pyruvate is the fastest acting of several M. robertsii ROS scavengers, efficiently reducing protein carbonylation, stabilizing mitochondrial membrane potential, and promoting fungal growth. The acetate produced from pyruvate-ROS reactions itself causes acid stress, tolerance to which is regulated by Hog1 mitogen-activated protein kinase. Heat stress also induces pyruvate accumulation in several other fungi, suggesting that scavenging of heat-induced ROS by pyruvate is widespread. Heat is a dangerous challenge for most organisms, as it denatures proteins and induces the production of ROS that inactivate proteins, lipid membranes, and DNA. How organisms respond to this stress is not fully understood. Using the experimentally tractable insect pathogen Metarhizium robertsii as a model organism, we show for the first time that heat stress induces pyruvate production and that this functions as the first line of defense against heat-induced ROS. Heat stress also induces rapid pyruvate accumulation in other fungi, suggesting that pyruvate is a common but unappreciated defense against stress.
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Microbial cyclophilins: specialized functions in virulence and beyond. World J Microbiol Biotechnol 2017; 33:164. [PMID: 28791545 DOI: 10.1007/s11274-017-2330-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/05/2017] [Indexed: 01/18/2023]
Abstract
Cyclophilins belong to the superfamily of peptidyl-prolyl cis/trans isomerases (PPIases, EC: 5.2.1.8), the enzymes that catalyze the cis/trans isomerization of peptidyl-prolyl peptide bonds in unfolded and partially folded polypeptide chains and native state proteins. Cyclophilins have been extensively studied, since they are involved in multiple cellular processes related to human pathologies, such as neurodegenerative disorders, infectious diseases, and cancer. However, the presence of cyclophilins in all domains of life indicates a broader biological importance. In this mini-review, we summarize current advances in the study of microbial cyclophilins. Apart from their anticipated role in protein folding and chaperoning, cyclophilins are involved in several other biological processes, such as cellular signal transduction, adaptation to stress, control of pathogens virulence, and modulation of host immune response. Since many existing family members do not have well-defined functions and novel ones are being characterized, the requirement for further studies on their biological role and molecular mechanism of action is apparent.
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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] [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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Kanakala S, Ghanim M. Implication of the Whitefly Bemisia tabaci Cyclophilin B Protein in the Transmission of Tomato yellow leaf curl virus. FRONTIERS IN PLANT SCIENCE 2016; 7:1702. [PMID: 27895657 PMCID: PMC5109225 DOI: 10.3389/fpls.2016.01702] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/28/2016] [Indexed: 05/05/2023]
Abstract
Tomato yellow leaf curl virus (TYLCV) is a single-stranded (ssDNA) begomoviruses that causes severe damage to tomato and several other crops worldwide. TYLCV is exclusively transmitted by the sweetpotato whitefly, Bemisia tabaci in a persistent circulative and propagative manner. Previous studies have shown that the transmission, retention, and circulation of TYLCV in its vector involves interaction with insect and endosymbiont proteins, which aid in the transmission of the virus, or have a protective role in response to the presence of the virus in the insect body. However, only a low number of such proteins have been identified. Here, the role of B. tabaci Cyclophilin B (CypB) in the transmission of TYLCV protein was investigated. Cyclophilins are a large family of cellular prolyl isomerases that have many molecular roles including facilitating protein-protein interactions in the cell. One cyclophilin protein has been implicated in aphid-luteovirus interactions. We demonstrate that the expression of CypB from B. tabaci is altered upon TYLCV acquisition and retention. Further experiments used immunocapture-PCR and co-immunolocalization and demonstrated a specific interaction and colocalization between CypB and TYLCV in the the midgut, eggs, and salivary glands. Membrane feeding of anti-CypB antibodies and TYLCV-infected plants showed a decrease in TYLCV transmission, suggesting a critical role that CypB plays in TYLCV transmission. Further experiments, which used membrane feeding with the CypB inhibitor Cyclosporin A showed decrease in CypB-TYLCV colocalization in the midgut and virus transmission. Altogether, our results indicate that CypB plays an important role in TYLCV transmission by B. tabaci.
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