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Zhou J, Wang S, Xia Y, Peng G. MaAzaR, a Zn 2Cys 6/Fungus-Specific Transcriptional Factor, Is Involved in Stress Tolerance and Conidiation Pattern Shift in Metarhizium acridum. J Fungi (Basel) 2024; 10:468. [PMID: 39057353 PMCID: PMC11278141 DOI: 10.3390/jof10070468] [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: 06/11/2024] [Revised: 06/28/2024] [Accepted: 06/29/2024] [Indexed: 07/28/2024] Open
Abstract
Entomopathogenic fungi are valuable sources of biological pesticides, with conidial yield and quality being pivotal factors determining their broad applications. AzaR, a fungus-specific zinc-cluster transcription factor, is known to regulate the biosynthesis of polyketone secondary metabolites in Aspergillus niger; however, its role in pathogenic fungi remains unclear. This study investigated the role of MaAzaR in the growth, development, and environmental tolerance of Metarhizium acridum. MaAzaR deletion slowed down conidial germination rate, caused reduction in conidial yield, lowered fungal tolerance to UV radiation, did not affect fungal heat-shock tolerance, and increased fungal sensitivity to the cell-wall-destructive agent calcofluor white. Furthermore, MaAzaR deletion transformed microcycle conidiation to normal conidiation on the microcycle conidiation medium. Transcription profile analysis demonstrated that MaAzaR could regulate transformation of the conidiation pattern by controlling the expression of genes related to cell division, mycelium growth and development, and cell wall integrity. Thus, this study identified a new gene related to fungal conidiation and environmental tolerance, enriching our understanding of the molecular mechanism of microcycle conidiation and providing theoretical support and genetic resources for the development of high-yielding strains.
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Affiliation(s)
- Jinyuan Zhou
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Siqin Wang
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Yuxian Xia
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
| | - Guoxiong Peng
- Genetic Engineering Research Center, School of Life Sciences, Chongqing University, Chongqing 401331, China
- Chongqing Engineering Research Center for Fungal Insecticide, Chongqing 401331, China
- Key Laboratory of Gene Function and Regulation Technologies Under Chongqing Municipal Education Commission, Chongqing 401331, China
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2
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Pan J, Yang X, Hu C, Fu T, Zhang X, Liu Z, Wang Y, Zhang F, He X, Yu JH. Functional, transcriptomic, and lipidomic studies of the choC gene encoding a phospholipid methyltransferase in Aspergillus fumigatus. Microbiol Spectr 2024; 12:e0216823. [PMID: 38009944 PMCID: PMC10783049 DOI: 10.1128/spectrum.02168-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/02/2023] [Indexed: 11/29/2023] Open
Abstract
IMPORTANCE This study explored the phospholipid metabolic pathway in A. fumigatus and its relationship with fungal growth, metabolism, and pathogenicity. ChoC, based on its critical roles in many aspects of the fungus and relatively conserved characteristics in filamentous fungi with low similarity with mammalian ones, can be a novel target of new antifungal drugs.
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Affiliation(s)
- Jiao Pan
- Institute for Cultural Heritage and History of Science and Technology, University of Science and Technology Beijing, Beijing, China
| | - Xinyu Yang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Cuiting Hu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Tongtong Fu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiuyan Zhang
- College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zijun Liu
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Yu Wang
- Institute for Cultural Heritage and History of Science and Technology, University of Science and Technology Beijing, Beijing, China
| | - Fengyu Zhang
- Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Xiaoyuan He
- Department of Hematology, Tianjin First Central Hospital, Tianjin, China
| | - Jae-Hyuk Yu
- Department of Bacteriology, Food Research Institute, University of Wisconsin, Madison, Wisconsin, USA
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3
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Sun YX, Zhang BX, Zhang WT, Wang Q, Toufeeq S, Rao XJ. UV-induced mutagenesis of Beauveria bassiana (Hypocreales: Clavicipitaceae) yields two hypervirulent isolates with different transcriptomic profiles. PEST MANAGEMENT SCIENCE 2023. [PMID: 36914429 DOI: 10.1002/ps.7452] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 01/31/2023] [Accepted: 03/14/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND The fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) can infest over 300 plant species and cause huge economic losses. Beauveria bassiana (Hypocreales: Clavicipitaceae) is one of the most widely used entomopathogenic fungi (EPF). Unfortunately, the efficacy of B. bassiana against S. frugiperda is quite low. Hypervirulent EPF isolates can be obtained by ultraviolet (UV)-irradiation. Here we report on the UV-induced mutagenesis and transcriptomic analysis of B. bassiana. RESULTS The wild-type (WT) B. bassiana (ARSEF2860) was exposed to UV light to induce mutagenesis. Two mutants (named 6M and 8M) showed higher growth rates, conidial yields, and germination rates compared to the WT strain. The mutants showed higher levels of tolerance to osmotic, oxidative, and UV stresses. The mutants showed higher protease, chitinase, cellulose, and chitinase activities than WT. Both WT and mutants were compatible with the insecticides matrine, spinetoram, and chlorantraniliprole, but incompatible with emamectin benzoate. Insect bioassays showed that both mutants were more virulent against S. frugiperda and the greater wax moth Galleria mellonella. Transcriptomic profiles of the WT and mutants were determined by RNA-sequencing. The differentially expressed genes (DEGs) were identified. The gene set enrichment analysis (GSEA), protein-protein interaction (PPI) network, and hub gene analysis revealed virulence-related genes. CONCLUSION Our data demonstrate that UV-irradiation is a very efficient and economical technique to improve the virulence and stress resistance of B. bassiana. Comparative transcriptomic profiles of the mutants provide insights into virulence genes. These results provide new ideas for improving the genetic engineering and field efficacy of EPF. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Yan-Xia Sun
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China
| | - Bang-Xian Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China
- Department of Science and Technology, Chuzhou University, Chuzhou, China
| | - Wen-Ting Zhang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China
| | - Qian Wang
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China
| | - Shahzad Toufeeq
- Key Laboratory of Insect Development and Evolutionary Biology, CAS Center for Excellence in Molecular Plant Sciences, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, China
| | - Xiang-Jun Rao
- Key Laboratory of Biology and Sustainable Management of Plant Diseases and Pests of Anhui Higher Education Institutes, School of Plant Protection, Anhui Agricultural University, Hefei, China
- Anhui Province Key Laboratory of Integrated Pest Management on Crops, Hefei, China
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4
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Tong C, Wei J, Pan G, Li C, Zhou Z. Study of Pathogenesis Using Fluorescent Strain of Cordyceps farinosa Revealed Infection of Thitarodes armoricanus Larvae via Digestive Tract. INSECTS 2022; 13:1039. [PMID: 36354862 PMCID: PMC9698661 DOI: 10.3390/insects13111039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 10/28/2022] [Accepted: 11/08/2022] [Indexed: 06/16/2023]
Abstract
Cordyceps farinosa is often utilized as a biocontrol agent because of its wide host range, strong lethality, and safety for mammals. Artificial rearing of Thitarodes armoricanus larvae is a prerequisite for the artificial cultivation of Chinese cordyceps, and C. farinosa is the most lethal pathogenic fungus during the rearing process. However, the infection process of C. farinosa is still unclear. In this study, we cloned the promoter of the C. farinosa glyceraldehyde 3-phosphate dehydrogenase gene, constructed the EGFP expression cassette, and integrated it into the C. farinosa genome via Agrobacterium transformation. We obtained a fluorescent strain for better observation of the infection process. Using two different inoculation methods of the fluorescent strain, we observed the traditional infection process through the body surface as well as through the digestive tract via feeding. Both infection modes can lead to larval death and mummification. Our findings demonstrated that during the artificial rearing of T. armoricanus, preventing C. farinosa pollution should be an important part of the disinfection of the rearing environment.
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Affiliation(s)
- Chaoqun Tong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Junhong Wei
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Guoqing Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Chunfeng Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
| | - Zeyang Zhou
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Microsporidia Infection and Prevention, Southwest University, Chongqing 400715, China
- College of Life Sciences, Chongqing Normal University, Chongqing 401331, China
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5
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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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6
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Li M, Huang H, Liu J, Zhang X, Li Q, Li D, Luo M, Wang X, Zeng W, Sun J, Liu H, Xi L. Deletion C-terminal thioesterase abolishes melanin biosynthesis, affects metabolism and reduces the pathogenesis of Fonsecaea monophora. PLoS Negl Trop Dis 2022; 16:e0010485. [PMID: 35696422 PMCID: PMC9255740 DOI: 10.1371/journal.pntd.0010485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/05/2022] [Accepted: 05/09/2022] [Indexed: 12/05/2022] Open
Abstract
Dematiaceous Fonsecaea monophora is one of the major pathogens of chromoblastomycosis. It has been well established that melanization is catalyzed by the type I polyketide synthase (PKS) in F. monophora. Multidomain protein Type I PKS is encoded by six genes, in which the last enzyme thioesterase (TE) catalyzes the cyclization and releases polyketide. Two PKS genes AYO21_03016 (pks1) and AYO21_10638 have been found in F. monophora and both PKS loci have the same gene arrangement but the TE domain in AYO21_10638 is truncated at 3’- end. TE may be the key enzyme to maintain the function of pks1. To test this hypothesis, we constructed a 3’-end 500 bp deletion mutant of AYO21_03016 (Δpks1-TE-C500) and its complemented strain. We profiled metabolome of this mutant and analyzed the consequences of impaired metabolism in this mutant by fungal growth in vitro and by pathogenesis in vivo. Compared with wild-type strain, we found that the mutant repressed pks1 expression and other 5 genes expression levels were reduced by more than 50%, perhaps leading to a corresponding melanin loss. The mutant also reduced sporulation and delayed germination, became vulnerable to various environmental stresses and was less resistance to macrophage or neutrophil killings in vitro, and less virulence in mice footpad model. Metabolomic analysis indicated that many metabolites were remarkably affected in Δpks1-TE-C500, in particular, an increased nicotinamide and antioxidant glutathione. In conclusion, we confirmed the crucial role of C-terminal TE in maintaining fully function of pks1 in F. monophora. Deletion of TE negatively impacts on the synthesis of melanin and metabolites that eventually affect growth and virulence of F. monophora. Any potential inhibitor of TE then could be a novel antifungal target for drug development. F. monophora is a fungal pathogen that causes chromoblastomycosis. Melanin of F. monophora was synthesized through PKS in which TE is the last enzyme to catalyze the cyclization and release polyketide. Few studies have investigated the effect of TE on the metabolism and pathogenesis of F. monophora. In this study, TE deletion leads to albino phenotype, decreases the expression of other domains of the pks1, and reduces biosynthesis of metabolites. The Δpks1-TE-C500 strain exhibits a changed morphogenesis and becomes less resistant to various environmental stresses. In vitro study, the Δpks1-TE-C500 strain is avirulent and less resistant to macrophages and neutrophils. In conclusion, we demonstrate that the 500 bp C-terminal of TE is essential for the function of pks1, perhaps through its effects on melanin and metabolites to regulate the growth and virulence of F. monophora. Data from this study could inspire an exploration in development of clinical therapy for CBM.
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Affiliation(s)
- Minying Li
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Huan Huang
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Jun Liu
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Xiaohui Zhang
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Qian Li
- Guangdong Clinical College of Dermatology, Anhui Medical University, Guangzhou, China
| | - Dongmei Li
- Department of Microbiology-Immunology, Georgetown University Medical Center, Washington, District of Columbia, United States of America
| | - Mingfen Luo
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Xiaoyue Wang
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Weiying Zeng
- Dermatology Hospital, Southern Medical University, Guangzhou, China
| | - Jiufeng Sun
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangdong, Guangzhou, China
| | - Hongfang Liu
- Dermatology Hospital, Southern Medical University, Guangzhou, China
- * E-mail: (HL); (LX)
| | - Liyan Xi
- Dermatology Hospital, Southern Medical University, Guangzhou, China
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
- * E-mail: (HL); (LX)
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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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8
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Palmer JM, Wiemann P, Greco C, Chiang YM, Wang CCC, Lindner DL, Keller NP. The sexual spore pigment asperthecin is required for normal ascospore production and protection from UV light in Aspergillus nidulans. J Ind Microbiol Biotechnol 2021; 48:6355442. [PMID: 34415047 PMCID: PMC8762651 DOI: 10.1093/jimb/kuab055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/03/2021] [Indexed: 11/12/2022]
Abstract
Many fungi develop both asexual and sexual spores that serve as propagules for dissemination and/or recombination of genetic traits. Asexual spores are often heavily pigmented and this pigmentation provides protection from UV light. However, little is known about any purpose pigmentation may serve for sexual spores. The model Ascomycete Aspergillus nidulans produces both green pigmented asexual spores (conidia) and red pigmented sexual spores (ascospores). Here we find that the previously characterized red pigment, asperthecin, is the A. nidulans ascospore pigment. The asperthecin biosynthetic gene cluster is composed of three genes, aptA, aptB, and aptC where deletion of either aptA (encoding a polyketide synthase) or aptB (encoding a thioesterase) yields small, mishappen hyaline ascospores while deletion of aptC (encoding a monooxygenase) yields morphologically normal but purple ascospores. ∆aptA and ∆aptB but not ∆aptC or WT ascospores are extremely sensitive to UV light. We find that two historical ascospore color mutants, clA6 and clB1, possess mutations in aptA and aptB sequences respectively.
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Affiliation(s)
- Jonathan M Palmer
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA.,Center for Forest Mycology Research, Northern Research Station, US Forest Service, Madison, WI 53726, USA
| | - Philipp Wiemann
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Claudio Greco
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yi Ming Chiang
- Departments of Chemistry and Pharmacology & Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Clay C C Wang
- Departments of Chemistry and Pharmacology & Pharmaceutical Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Daniel L Lindner
- Center for Forest Mycology Research, Northern Research Station, US Forest Service, Madison, WI 53726, USA
| | - Nancy P Keller
- Department of Medical Microbiology & Immunology, University of Wisconsin-Madison, Madison, WI 53706, USA.,Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
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9
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Meng X, Liao Z, Liu T, Hussain K, Chen J, Fang Q, Wang J. Vital roles of Pks11, a highly reducing polyketide synthase, in fungal conidiation, antioxidant activity, conidial cell wall integrity, and UV tolerance of Beauveria bassiana. J Invertebr Pathol 2021; 181:107588. [PMID: 33862054 DOI: 10.1016/j.jip.2021.107588] [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: 12/09/2020] [Revised: 03/23/2021] [Accepted: 04/06/2021] [Indexed: 01/24/2023]
Abstract
Fungal polyketide synthases play important and differential roles in synthesizing secondary metabolites and regulating several cell events, including asexual development, environmental adaptation, and pathogenicity. This study shows the important functions of a highly reducing polyketide synthase, Pks11, in Beauveria bassiana, a filamentous fungal insect pathogen used worldwide for pest biocontrol. The deletion of pks11 led to severe defects in conidial yields on different media and a decrease of 36.27% in the mean thickness of conidial cell wall under normal conditions. Compared with the wild-type, Δpks11 showed higher tolerance to oxidation and increased sensitivity to high temperature during colony growth. Moreover, the lack of pks11 caused a decrease in conidial germination after exposure to UV radiation but did not affect the virulence of B. bassiana against Galleria mellonella larvae via typical cuticle infection. These findings concurred with the alteration in the transcript levels of some phenotype-related genes. These data suggested that pks11 played vital roles in the asexual development, cell wall integrity, and fungal responses to oxidation, high temperature, and UV irradiation of B. bassiana.
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Affiliation(s)
- Xiaolin Meng
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Zhenlin Liao
- College of Food Science, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China
| | - Tong Liu
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Kashif Hussain
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Jianwen Chen
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Qian'an Fang
- College of Food Science, South China Agricultural University, Guangzhou 510642, China
| | - Jie Wang
- College of Food Science, South China Agricultural University, Guangzhou 510642, China; Lingnan Guangdong Laboratory of Modern Agriculture, Guangzhou 510642, China.
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10
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The polyketide synthase PKS15 has a crucial role in cell wall formation in Beauveria bassiana. Sci Rep 2020; 10:12630. [PMID: 32724143 PMCID: PMC7387532 DOI: 10.1038/s41598-020-69417-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 06/30/2020] [Indexed: 12/13/2022] Open
Abstract
Entomopathogenic fungi utilize specific secondary metabolites to defend against insect immunity, thereby enabling colonization of their specific hosts. We are particularly interested in the polyketide synthesis gene pks15, which is involved in metabolite production, and its role in fungal virulence. Targeted disruption of pks15 followed by genetic complementation with a functional copy of the gene would allow for functional characterization of this secondary metabolite biosynthesis gene. Using a Beauveria bassiana ∆pks15 mutant previously disrupted by a bialophos-resistance (bar) cassette, we report here an in-cis complementation at bar cassette using CRISPR/Cas9 gene editing. A bar-specific short guide RNA was used to target and cause a double-strand break in bar, and a donor DNA carrying a wild-type copy of pks15 was co-transformed with the guide RNA. Isolate G6 of ∆pks15 complemented with pks15 was obtained and verified by PCR, Southern analyses and DNA sequencing. Compared to ∆pks15 which showed a marked reduction in sporulation and insect virulence, the complementation in G6 restored with insect virulence, sporulation and conidial germination to wild-type levels. Atomic force and scanning electron microscopy revealed that G6 and wild-type conidial wall surfaces possessed the characteristic rodlet bundles and rough surface while ∆pks15 walls lacked the bundles and were relatively smoother. Conidia of ∆pks15 were larger and more elongated than that of G6 and the wild type, indicating changes in their cell wall organization. Our data indicate that PKS15 and its metabolite are likely not only important for fungal virulence and asexual reproduction, but also cell wall formation.
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