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Espín-Sánchez D, Preisegger L, Mazzolenis R, Santana M, Saparrat MCN, Pedrini N, Huarte-Bonnet C. Dark Pigments in Entomopathogenic Fungal Microsclerotia: Preliminary Evidence of a 1,8-Dihydroxynaphthalene-melanin-like Compound in Metarhizium robertsii. J Fungi (Basel) 2023; 9:1162. [PMID: 38132763 PMCID: PMC10744409 DOI: 10.3390/jof9121162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 11/23/2023] [Accepted: 11/29/2023] [Indexed: 12/23/2023] Open
Abstract
Metarhizium robertsii microsclerotia are fungal aggregates composed of compacted, pigmented hyphae. As they are highly tolerant to desiccation and produce infective conidia, they are promising candidates to be formulated as bioinsecticides. Despite this potential, the nature of the pigments within these structures remains unclear. In this study, routine culture media used for the differentiation of M. robertsii microsclerotia were supplemented with four melanin inhibitors, and the resulting propagules were characterized. Inhibitors of the 1,8-dihydroxynaphthalene (DHN)-melanin biosynthetic pathway such as tricyclazole and guaiacol induced significant phenotypic and molecular modifications in the obtained M. robertsii propagules, which exhibited a more spherical shape, reduced size, and increased susceptibility to desiccation, heat, and oxidative stress than microsclerotia obtained without inhibitors. Additionally, genes encoding for a polyketide synthase (Mrpks2) and a putative 1,3,6,8-tetrahydroxynaphthalene reductase (Mrthnr), potentially involved in the DHN-melanin biosynthetic pathway, were upregulated in fungi grown in the inhibitor-added media. In conclusion, M. robertsii microsclerotia contain melanins of type DHN that might play a role in both microsclerotia differentiation and environmental stress tolerance.
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Affiliation(s)
- Daysi Espín-Sánchez
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
| | - Lautaro Preisegger
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
| | - Romina Mazzolenis
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
| | - Marianela Santana
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
| | - Mario C. N. Saparrat
- Instituto de Fisiología Vegetal (INFIVE), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina;
| | - Nicolás Pedrini
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
| | - Carla Huarte-Bonnet
- Instituto de Investigaciones Bioquímicas de La Plata “Profesor Doctor Rodolfo R. Brenner” (INIBIOLP), Universidad Nacional de La Plata (UNLP)-CCT-La Plata-CONICET, La Plata 1900, Argentina; (D.E.-S.); (L.P.); (R.M.); (M.S.)
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Luo N, Li Z, Ling J, Zhao J, Li Y, Yang Y, Mao Z, Xie B, Li H, Jiao Y. Establishment of a CRISPR/Cas9-Mediated Efficient Knockout System of Trichoderma hamatum T21 and Pigment Synthesis PKS Gene Knockout. J Fungi (Basel) 2023; 9:jof9050595. [PMID: 37233306 DOI: 10.3390/jof9050595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/10/2023] [Accepted: 05/17/2023] [Indexed: 05/27/2023] Open
Abstract
Trichoderma hamatum is a filamentous fungus that serves as a biological control agent for multiple phytopathogens and as an important resource promising for fungicides. However, the lack of adequate knockout technologies has hindered gene function and biocontrol mechanism research of this species. This study obtained a genome assembly of T. hamatum T21, with a 41.4 Mb genome sequence comprising 8170 genes. Based on genomic information, we established a CRISPR/Cas9 system with dual sgRNAs targets and dual screening markers. CRISPR/Cas9 plasmid and donor DNA recombinant plasmid were constructed for disruption of the Thpyr4 and Thpks1 genes. The result indicates the consistency between phenotypic characterization and molecular identification of the knockout strains. The knockout efficiencies of Thpyr4 and Thpks1 were 100% and 89.1%, respectively. Moreover, sequencing revealed fragment deletions between dual sgRNA target sites or GFP gene insertions presented in knockout strains. The situations were caused by different DNA repair mechanisms, nonhomologous end joining (NHEJ), and homologous recombination (HR). Overall, we have successfully constructed an efficient and convenient CRISPR/Cas9 system in T. hamatum for the first time, which has important scientific significance and application value for studies on functional genomics of Trichoderma and other filamentous fungi.
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Affiliation(s)
- Ning Luo
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, College of Plant Protection, Gansu Agricultural University, Lanzhou 730070, China
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zeyu Li
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jian Ling
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jianlong Zhao
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yan Li
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Yuhong Yang
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Zhenchuan Mao
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Bingyan Xie
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Huixia Li
- Biocontrol Engineering Laboratory of Crop Diseases and Pests of Gansu Province, College of Plant Protection, Gansu Agricultural University, Lanzhou 730070, China
| | - Yang Jiao
- State Key Laboratory of Vegetable Biobreeding, Institute of Vegetables and Flower, Chinese Academy of Agricultural Sciences, Beijing 100081, China
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Wu H, Tong Y, Wang C, Yu Y, Chen M, Wang Y, Li X, Huang B. Metarhizium robertsii MrAbaA affects conidial pigmentation via regulating MrPks1 and MrMlac1 expression. J Invertebr Pathol 2023; 197:107892. [PMID: 36720345 DOI: 10.1016/j.jip.2023.107892] [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: 10/16/2022] [Revised: 01/13/2023] [Accepted: 01/24/2023] [Indexed: 02/02/2023]
Abstract
Pigments of conidia play a crucial role in fungal defense against environmental stressors such as UV radiation. The molecular basis of conidial pigmentation has been studied in the entomopathogenic fungus Metarhizium robertsii, while limited information been reported on function mechanisms transcription factors governing conidial pigmentation. Here, we identified transcription factor MrAbaA binding to the promoter regions of both MrPks1 and MrMlac1 in M. robertsii using yeast one-hybrid technology. Chromatin immunoprecipitation quantitative PCR assays further confirmed the interaction. Furthermore, overexpression of MrAbaA in M. robertsii resulted in increased conidial pigment accumulation and enhanced tolerances to UV stress by upregulated the MrPks1 and MrMlac1 expression. Taken together, MrAbaA affects conidial pigmentation by interacting with the promoter regions of both MrPks1 and MrMlac1 in M. robertsii. This work advances the understanding of the regulation mechanism for conidial pigmentation in entomopathogenic fungi.
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Affiliation(s)
- Hao Wu
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China; School of Life Sciences, Anhui Medical University, Hefei 230032, China
| | - Youmin Tong
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Cuiming Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Yashuai Yu
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Mingyue Chen
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Yulong Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China
| | - Xiaojuan Li
- Key Laboratory of State Forestry Administration on Prevention and Control of Pine Wood Nematode Disease, Anhui Academy of Forestry, Hefei 230088, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei 230036, China.
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Vidhate RP, Dawkar VV, Punekar SA, Giri AP. Genomic Determinants of Entomopathogenic Fungi and Their Involvement in Pathogenesis. MICROBIAL ECOLOGY 2023; 85:49-60. [PMID: 34977966 DOI: 10.1007/s00248-021-01936-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 11/24/2021] [Indexed: 06/14/2023]
Abstract
Entomopathogenic fungi offer an effective and eco-friendly alternative to curb insect populations in biocontrol strategy. The evolutionary history of selected entomopathogenic fungi indicates their ancestral relationship with plant endophytes. During this host shifting, entomopathogenic fungi must have acquired multiple mechanisms, including a combination of various biomolecules that make them distinguishable from other fungi. In this review, we focus on understanding various biochemical and molecular mechanisms involved in entomopathogenesis. In particular, we attempt to explain the indispensable role of enlarged gene families of various virulent factors, viz. chitinases, proteases, lipases, specialized metabolites, and cytochrome P450, in entomopathogenesis. Our analysis suggests that entomopathogenic fungi recruit a different set of gene products during the progression of pathogenesis. Knowledge of these bio-molecular interactions between fungi and insect hosts will allow researchers to execute pointed efforts towards the development of improved entomopathogenic fungal strains.
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Affiliation(s)
- Ravindra P Vidhate
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India
| | - Vishal V Dawkar
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India
| | - Sachin A Punekar
- Biospheres, Eshwari, 52/403, Lakshminagar, Parvati, Pune, 411009, Maharashtra, India
| | - Ashok P Giri
- Plant Molecular Biology Unit, Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, 411008, Maharashtra, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, Uttar Pradesh, India.
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5
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Host and Environmental Sensing by Entomopathogenic Fungi to Infect Hosts. CURRENT CLINICAL MICROBIOLOGY REPORTS 2022. [DOI: 10.1007/s40588-022-00185-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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6
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OVAT Analysis and Response Surface Methodology Based on Nutrient Sources for Optimization of Pigment Production in the Marine-Derived Fungus Talaromyces albobiverticillius 30548 Submerged Fermentation. Mar Drugs 2021; 19:md19050248. [PMID: 33925595 PMCID: PMC8146719 DOI: 10.3390/md19050248] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/24/2021] [Accepted: 04/25/2021] [Indexed: 11/17/2022] Open
Abstract
Pigment production from filamentous fungi is gaining interest due to the diversity of fungal species, the variety of compounds synthesized, and the possibility of controlled massive productions. The Talaromyces species produce a large panel of metabolites, including Monascus-like azaphilone pigments, with potential use as natural colorants in industrial applications. Optimizing pigment production from fungal strains grown on different carbon and nitrogen sources, using statistical methods, is widespread nowadays. The present work is the first in an attempt to optimize pigments production in a culture of the marine-derived T. albobiverticillius 30548, under the influence of several nutrients sources. Nutrient combinations were screened through the one-variable-at-a-time (OVAT) analysis. Sucrose combined with yeast extract provided a maximum yield of orange pigments (OPY) and red pigments (RPY) (respectively, 1.39 g/L quinizarin equivalent and 2.44 g/L Red Yeast pigment equivalent), as well as higher dry biomass (DBW) (6.60 g/L). Significant medium components (yeast extract, K2HPO4 and MgSO4·7H2O) were also identified from one-variable-at-a-time (OVAT) analysis for pigment and biomass production. A five-level central composite design (CCD) and a response surface methodology (RSM) were applied to evaluate the optimal concentrations and interactive effects between selected nutrients. The experimental results were well fitted with the chosen statistical model. The predicted maximum response for OPY (1.43 g/L), RPY (2.59 g/L), and DBW (15.98 g/L) were obtained at 3 g/L yeast extract, 1 g/L K2HPO4, and 0.2 g/L MgSO4·7H2O. Such optimization is of great significance for the selection of key nutrients and their concentrations in order to increase the pigment production at a pilot or industrial scale.
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Jia SL, Chi Z, Chen L, Liu GL, Hu Z, Chi ZM. Molecular evolution and regulation of DHN melanin-related gene clusters are closely related to adaptation of different melanin-producing fungi. Genomics 2021; 113:1962-1975. [PMID: 33901575 DOI: 10.1016/j.ygeno.2021.04.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 03/31/2021] [Accepted: 04/20/2021] [Indexed: 12/31/2022]
Abstract
Many genes responsible for melanin biosynthesis in fungi were physically linked together. The PKS gene clusters in most of the melanin-producing fungi were regulated by the Cmr1. It was found that a close rearrangement of the PKS gene clusters had evolved in most of the melanin-producing fungi and various functions of melanin in them were beneficial to their adaptation to the changing environments. The melanin-producing fungi had undergone at least five large-scale differentiations, making their PKS gene clusters be quickly evolved and the fungi be adapted to different harsh environments. The recent gene losses and expansion were remarkably frequent in the PKS gene clusters, leading to their rapid evolution and adaptation of their hosts to different environments. The PKS gene and the CMR1 gene in them were subject to a strong co-evolution, but the horizontal gene transfer events might have occurred in the genome-duplicated species, Aspergillus and Penicillium.
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Affiliation(s)
- Shu-Lei Jia
- College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China
| | - Zhe Chi
- College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266003 Qingdao, China
| | - Lu Chen
- College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266003 Qingdao, China
| | - Guang-Lei Liu
- College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266003 Qingdao, China
| | - Zhong Hu
- Department of Biology, Shantou University, Shantou 515063, China
| | - Zhen-Ming Chi
- College of Marine Life Sciences, Ocean University of China, Yushan Road, No. 5, Qingdao, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, 266003 Qingdao, China.
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8
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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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Cheng JT, Yu JH, Sun CF, Cao F, Ying YM, Zhan ZJ, Li WJ, Chen XA, Zhao QW, Li YQ, Gan LS, Mao XM. A Cell Factory of a Fungicolous Fungus Calcarisporium arbuscula for Efficient Production of Natural Products. ACS Synth Biol 2021; 10:698-706. [PMID: 33720696 DOI: 10.1021/acssynbio.0c00371] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Fungal natural products are rich sources of clinical drugs. Particularly, the fungicolous fungi have a large number of biosynthetic gene clusters (BGCs) to produce numerous bioactive natural products, but most BGCs are silent in the laboratory. We have shown that a fungicolous fungus Calcarisporium arbuscula NRRL 3705 predominantly produces the highly reduced polyketide-type mycotoxins aurovertins. Here after evaluation of the aurovertin-null mutant ΔaurA as an efficient host, we further screened two strong promoters aurBp and A07068p based on RNA-Seq, and successfully activated an endogenous gene cluster from C. arbuscula as well as three additional exogenous BGCs from other fungi to produce polyketide-type natural products. Thus, we showed an efficient expression system from the fungicolous fungus C. arbuscula, which will be highly beneficial and complementary to the conventional Aspergillus and Penicillium fungal cell factories, and provides a useful toolkit for genome-wide mining of bioactive natural products from fungicolous fungi.
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Affiliation(s)
- Jin-Tao Cheng
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
| | - Jia-Hui Yu
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, Guangdong 529020, P. R. China
| | - Chen-Fan Sun
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
| | - Fei Cao
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
| | - You-Min Ying
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
| | - Zha-Jun Zhan
- College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou, 310014, P. R. China
| | - Wen-Ju Li
- Jinan Samuel Pharmaceutical Co., Ltd of Shandong Province, Jinan, 250100, P. R. China
| | - Xin-Ai Chen
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
| | - Qing-Wei Zhao
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Yong-Quan Li
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
| | - Li-She Gan
- School of Biotechnology and Health Sciences, Wuyi University, Jiangmen, Guangdong 529020, P. R. China
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, P. R. China
| | - Xu-Ming Mao
- Institute of Pharmaceutical Biotechnology & Research Center for Clinical Pharmacy, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, P. R. China
- Zhejiang Provincial Key Laboratory for Microbial Biochemistry and Metabolic Engineering, Hangzhou, 310058, P. R. China
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Zhang L, Fasoyin OE, Molnár I, Xu Y. Secondary metabolites from hypocrealean entomopathogenic fungi: novel bioactive compounds. Nat Prod Rep 2020; 37:1181-1206. [PMID: 32211639 PMCID: PMC7529686 DOI: 10.1039/c9np00065h] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Covering: 2014 up to the third quarter of 2019 Entomopathogens constitute a unique, specialized trophic subgroup of fungi, most of whose members belong to the order Hypocreales (class Sordariomycetes, phylum Ascomycota). These Hypocrealean Entomopathogenic Fungi (HEF) produce a large variety of secondary metabolites (SMs) and their genomes rank highly for the number of predicted, unique SM biosynthetic gene clusters. SMs from HEF have diverse roles in insect pathogenicity as virulence factors by modulating various interactions between the producer fungus and its insect host. In addition, these SMs also defend the carcass of the prey against opportunistic microbial invaders, mediate intra- and interspecies communication, and mitigate abiotic and biotic stresses. Thus, these SMs contribute to the role of HEF as commercial biopesticides in the context of integrated pest management systems, and provide lead compounds for the development of chemical pesticides for crop protection. These bioactive SMs also underpin the widespread use of certain HEF as nutraceuticals and traditional remedies, and allowed the modern pharmaceutical industry to repurpose some of these molecules as life-saving human medications. Herein, we survey the structures and biological activities of SMs described from HEF, and summarize new information on the roles of these metabolites in fungal virulence.
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Affiliation(s)
- Liwen Zhang
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P.R. China.
| | - Opemipo Esther Fasoyin
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P.R. China.
| | - István Molnár
- Southwest Center for Natural Products Research, University of Arizona, 250 E. Valencia Rd., Tucson, AZ 85706, USA.
| | - Yuquan Xu
- Biotechnology Research Institute, The Chinese Academy of Agricultural Sciences, 12 Zhongguancun South Street, Beijing 100081, P.R. China.
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Bioactive Metabolites and Potential Mycotoxins Produced by Cordyceps Fungi: A Review of Safety. Toxins (Basel) 2020; 12:toxins12060410. [PMID: 32575649 PMCID: PMC7354514 DOI: 10.3390/toxins12060410] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/19/2022] Open
Abstract
Ascomycete Cordyceps fungi such as C. militaris, C. cicadae, and C. guangdongensis have been mass produced on artificial media either as food supplements or health additives while the byproducts of culture substrates are largely used as animal feed. The safety concerns associated with the daily consumption of Cordyceps fungi or related products are still being debated. On the one hand, the known compounds from these fungi such as adenosine analogs cordycepin and pentostatin have demonstrated different beneficial or pharmaceutical activities but also dose-dependent cytotoxicities, neurological toxicities and or toxicological effects in humans and animals. On the other hand, the possibility of mycotoxin production by Cordyceps fungi has not been completely ruled out. In contrast to a few metabolites identified, an array of biosynthetic gene clusters (BGCs) are encoded in each genome of these fungi with the potential to produce a plethora of as yet unknown secondary metabolites. Conservation analysis of BGCs suggests that mycotoxin analogs of PR-toxin and trichothecenes might be produced by Cordyceps fungi. Future elucidation of the compounds produced by these functionally unknown BGCs, and in-depth assessments of metabolite bioactivity and chemical safety, will not only facilitate the safe use of Cordyceps fungi as human food or alternative medicine, but will also benefit the use of mass production byproducts as animal feed. To corroborate the long record of use as a traditional medicine, future efforts will also benefit the exploration of Cordyceps fungi for pharmaceutical purposes.
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12
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Chen L, Chi Z, Liu GL, Xue SJ, Wang ZP, Hu Z, Chi ZM. Improved pullulan production by a mutant of Aureobasidium melanogenum TN3-1 from a natural honey and capsule shell preparation. Int J Biol Macromol 2019; 141:268-277. [DOI: 10.1016/j.ijbiomac.2019.08.264] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 08/25/2019] [Accepted: 08/31/2019] [Indexed: 02/08/2023]
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13
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Wang J, Ma Y, Liu Y, Tong S, Zhu S, Jin D, Pei Y, Fan Y. A polyketide synthase, BbpksP, contributes to conidial cell wall structure and UV tolerance in Beauveria bassiana. J Invertebr Pathol 2019; 169:107280. [PMID: 31751556 DOI: 10.1016/j.jip.2019.107280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 10/25/2022]
Abstract
Conidial pigments of filamentous fungi play vital roles in fungal biotic/abiotic stress tolerance and are usually synthesized by polyketide synthases or other pigment synthesis proteins. Beauveria bassiana, an important insect pathogenic fungus used worldwide for pest biocontrol, produces white conidia on artificial media, while no conidial pigment has been observed or reported in it. However, real-time PCR and promoter-report analyses reveal a polyketide gene of B. bassiana (named BbpksP), homologous to melanin synthesis genes, is specifically expressed in aerial conidia. We show that deletion of BbpksP does not result in changes in conidial yield, germination rate or colony radial growth; however, the defect impairs conidial cell wall structure. A dense electron layer appears in the outer edge of the cell envelope in wild-type conidia, as observed by TEM, but this dense layer is absent in the ΔBbpksP mutant. The lack of BbpksP gene also reduces the UV-B tolerance of B. bassiana conidia. Bioassay reveals that deletion of BbpksP decreased virulence of B. bassiana against Galleria mellonella larvae via topical infection. These data indicate that the product(s) of BbpksP contributes to the integrity of the B. bassiana conidial cell wall and further affects the tolerance of UV-B stress and insecticidal activity.
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Affiliation(s)
- Junyao Wang
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Yuge Ma
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Yu Liu
- College of Biotechnology, Southwest University, Beibei, Chongqing, PR China
| | - Sheng Tong
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Shengan Zhu
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Dan Jin
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Yan Pei
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China
| | - Yanhua Fan
- Biotechnology Research Center, Southwest University, Beibei, Chongqing, PR China.
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14
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The phosphatase gene MaCdc14 negatively regulates UV-B tolerance by mediating the transcription of melanin synthesis-related genes and contributes to conidiation in Metarhizium acridum. Curr Genet 2019; 66:141-153. [PMID: 31256233 DOI: 10.1007/s00294-019-01008-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 06/19/2019] [Accepted: 06/22/2019] [Indexed: 10/26/2022]
Abstract
Reversible phosphorylation of proteins regulated by protein kinases and phosphatases mediate multiple biological events in eukaryotes. In this study, a dual-specificity cell division cycle 14 phosphatase, MaCdc14, was functionally characterized in Metarhizium acridum. Deletion of MaCdc14 decreased branch numbers, affected septum formation and resulted in multiple nuclei in each hyphal compartment, indicating nuclear division and cytokinesis defects. The spore production capacity was severely impaired with decreased conidial yield and delayed conidiation in MaCdc14-deletion mutant (ΔMaCdc14). The transcription levels of conidiation-related genes were significantly changed after MaCdc14 inactivation. The morphology of conidia was uneven in size and the germination rate of conidia was increased in ΔMaCdc14. In addition, ΔMaCdc14 displayed significantly enhanced conidial tolerance to ultraviolet (UV) irradiation but had no significant effect on the thermotolerance, the sensitivities to cell wall damage reagents, osmotic and oxidative stresses, and virulence compared to the wild-type strain and complementary transformant. Furthermore, the pigmentation of ΔMaCdc14 was increased by the upregulated expression of melanin synthesis-related genes, which may result in the enhanced UV-B tolerance of ΔMaCdc14. In summary, MaCdc14 negatively regulated UV-B tolerance by mediating the transcription of melanin synthesis-related genes, contributed to conidiation by regulating the expression levels of conidiation-related genes and also played important roles in cytokinesis and morphogenesis in Metarhizium acridum.
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15
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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: 49] [Impact Index Per Article: 8.2] [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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16
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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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17
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Yang W, Wu H, Wang Z, Sun Q, Qiao L, Huang B. The APSES Gene MrStuA Regulates Sporulation in Metarhizium robertsii. Front Microbiol 2018; 9:1208. [PMID: 29922271 PMCID: PMC5996154 DOI: 10.3389/fmicb.2018.01208] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/17/2018] [Indexed: 11/30/2022] Open
Abstract
The APSES family is a unique family of transcription factors with a basic helix-loop-helix structure (APSES: Asm1p, Phd1p, Sok2p, Efg1p, and StuAp), which are key regulators of cell development and sporulation-related processes. However, the functions of the APSES family of genes in the entomopathogenic fungus Metarhizium robertsii have not been reported. Here, we report the identification and characterization of the MrStuA gene, a member of the APSES family, in M. robertsii. The selected gene was identified as StuA in M. robertsii (MrStuA) because the gene product contains two conserved sequences, an APSES-type DNA-binding domain and a KilA DNA-binding domain, and has the highest homology with the StuA in the C-II clade of the APSES family. We found that the number of conidia produced by the ΔMrStuA strain was 94.45% lower than that in the wild type. Additionally, in the mutant, the conidia displayed an elongated shape, the sporulation was sparse and the phialide were slender. In addition, transcription levels of two central regulators of asexual development, AbaA and WetA, were significantly reduced in the mutant; furthermore, the transcription levels of other sporulation related genes, such as Mpk, Phi, Med, Aco, Flu, and FlbD, also decreased significantly. We also show that the median lethal time (LT50) of the mutant increased by 19%. This increase corresponded with a slower growth rate and an earlier conidia germination time compared to that of the wild strain. However, the resistance of the mutant to chemicals or physical stressors, such as ultraviolet radiation or heat, was not significantly altered. Our results indicate that in M. robertsii, MrStuA may play a crucial role in regulating sporulation as well as virulence, germination, and vegetative growth. This study improves our understanding of the impact of the transcription factor StuA on sporulation processes in filamentous fungi and provides a basis for further studies aimed at improving sporulation efficiency of these fungi for use as a biocontrol agent.
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Affiliation(s)
- Wenjing Yang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Hao Wu
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Zhangxun Wang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China.,School of Plant Protection, Anhui Agricultural University, Hefei, China
| | - Qian Sun
- School of Transportation Engineering, Anhui Sanlian University, Hefei, China
| | - Lintao Qiao
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
| | - Bo Huang
- Anhui Provincial Key Laboratory of Microbial Pest Control, Anhui Agricultural University, Hefei, China
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18
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Antioxidant enzymes and their contributions to biological control potential of fungal insect pathogens. Appl Microbiol Biotechnol 2018; 102:4995-5004. [DOI: 10.1007/s00253-018-9033-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/15/2018] [Accepted: 04/16/2018] [Indexed: 12/15/2022]
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19
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Pereira-Junior RA, Huarte-Bonnet C, Paixão FRS, Roberts DW, Luz C, Pedrini N, Fernandes ÉKK. Riboflavin induces Metarhizium spp. to produce conidia with elevated tolerance to UV-B, and upregulates photolyases, laccases and polyketide synthases genes. J Appl Microbiol 2018; 125:159-171. [PMID: 29473986 DOI: 10.1111/jam.13743] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Revised: 02/07/2018] [Accepted: 02/18/2018] [Indexed: 11/30/2022]
Abstract
AIMS The effect of nutritional supplementation of two Metarhizium species with riboflavin (Rb) during production of conidia was evaluated on (i) conidial tolerance (based on germination) to UV-B radiation and on (ii) conidial expression following UV-B irradiation, of enzymes known to be active in photoreactivation, viz., photolyase (Phr), laccase (Lac) and polyketide synthase (Pks). METHODS AND RESULTS Metarhizium acridum (ARSEF 324) and Metarhizium robertsii (ARSEF 2575) were grown either on (i) potato dextrose agar medium (PDA), (ii) PDA supplemented with 1% yeast extract (PDAY), (iii) PDA supplemented with Rb (PDA+Rb), or (iv) PDAY supplemented with Rb (PDAY+Rb). Resulting conidia were exposed to 866·7 mW m-2 of UV-B Quaite-weighted irradiance to total doses of 3·9 or 6·24 kJ m-2 . Some conidia also were exposed to 16 klux of white light (WL) after being irradiated, or not, with UV-B to investigate the role of possible photoreactivation. Relative germination of conidia produced on PDA+Rb (regardless Rb concentration) or on PDAY and exposed to UV-B was higher compared to conidia cultivated on PDA without Rb supplement, or to conidia suspended in Rb solution immediately prior to UV-B exposure. The expression of MaLac3 and MaPks2 for M. acridum, as well as MrPhr2, MrLac1, MrLac2 and MrLac3 for M. robertsii was higher when the isolates were cultivated on PDA+Rb and exposed to UV-B followed by exposure to WL, or exposed to WL only. CONCLUSIONS Rb in culture medium increases the UV-B tolerance of M. robertsii and M. acridum conidia, and which may be related to increased expression of Phr, Lac and Pks genes in these conidia. SIGNIFICANCE AND IMPACT OF THE STUDY The enhanced UV-B tolerance of Metarhizium spp. conidia produced on Rb-enriched media may improve the effectiveness of these fungi in biological control programs.
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Affiliation(s)
- R A Pereira-Junior
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.,Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata - CONICET, La Plata, Buenos Aires, Argentina
| | - C Huarte-Bonnet
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.,Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata - CONICET, La Plata, Buenos Aires, Argentina
| | - F R S Paixão
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil.,Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata - CONICET, La Plata, Buenos Aires, Argentina
| | - D W Roberts
- Department of Biology, Utah State University, Logan, UT, USA
| | - C Luz
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil
| | - N Pedrini
- Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), Universidad Nacional de La Plata - CONICET, La Plata, Buenos Aires, Argentina
| | - É K K Fernandes
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brazil
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20
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Zhang P, Wang X, Fan A, Zheng Y, Liu X, Wang S, Zou H, Oakley BR, Keller NP, Yin WB. A cryptic pigment biosynthetic pathway uncovered by heterologous expression is essential for conidial development inPestalotiopsis fici. Mol Microbiol 2017; 105:469-483. [DOI: 10.1111/mmi.13711] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2017] [Indexed: 01/15/2023]
Affiliation(s)
- Peng Zhang
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- College of Life Science, University of Chinese Academy of Sciences; Beijing People's Republic of China
| | - Xiuna Wang
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou People's Republic of China
| | - Aili Fan
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
| | - Yanjing Zheng
- Zhejiang Provincial (Wenzhou) Key Lab for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science; Wenzhou University; Wenzhou People's Republic of China
| | - Xingzhong Liu
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of Education Ministry, and School of Life Sciences; Fujian Agriculture and Forestry University; Fuzhou People's Republic of China
| | - Huixi Zou
- Zhejiang Provincial (Wenzhou) Key Lab for Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science; Wenzhou University; Wenzhou People's Republic of China
| | - Berl R. Oakley
- Department of Molecular Biosciences; University of Kansas; Lawrence KS USA
| | - Nancy P. Keller
- Department of Medical Microbiology and Immunology; University of Wisconsin-Madison; Madison Wisconsin, WI USA
| | - Wen-Bing Yin
- State Key Laboratory of Mycology; Institute of Microbiology, Chinese Academy of Sciences; Beijing People's Republic of China
- College of Life Science, University of Chinese Academy of Sciences; Beijing People's Republic of China
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21
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Zeng G, Chen X, Zhang X, Zhang Q, Xu C, Mi W, Guo N, Zhao H, You Y, Dryburgh FJ, Bidochka MJ, St. Leger RJ, Zhang L, Fang W. Genome-wide identification of pathogenicity, conidiation and colony sectorization genes in Metarhizium robertsii. Environ Microbiol 2017; 19:3896-3908. [DOI: 10.1111/1462-2920.13777] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 04/17/2017] [Accepted: 04/17/2017] [Indexed: 12/14/2022]
Affiliation(s)
- Guohong Zeng
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Xiaoxuan Chen
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Xing Zhang
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | | | - Chuan Xu
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Wubin Mi
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Na Guo
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Hong Zhao
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Yue You
- Institute of Microbiology; Zhejiang University; Hangzhou China
| | - Farah-Jade Dryburgh
- Department of Biological Sciences; Brock University; St. Catharines ON Canada
| | - Michael J. Bidochka
- Department of Biological Sciences; Brock University; St. Catharines ON Canada
| | | | - Lei Zhang
- School of Biological and Chemical Engineering; Zhejiang University of Science & Technology; Hangzhou China
| | - Weiguo Fang
- Institute of Microbiology; Zhejiang University; Hangzhou China
- Institute of Insect Sciences; Zhejiang University; Hangzhou China
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22
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Both a PKS and a PPTase are involved in melanin biosynthesis and regulation of Aureobasidium melanogenum XJ5-1 isolated from the Taklimakan desert. Gene 2017; 602:8-15. [DOI: 10.1016/j.gene.2016.11.020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 11/07/2016] [Accepted: 11/10/2016] [Indexed: 11/19/2022]
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23
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Wang C, Wang S. Insect Pathogenic Fungi: Genomics, Molecular Interactions, and Genetic Improvements. ANNUAL REVIEW OF ENTOMOLOGY 2017; 62:73-90. [PMID: 27860524 DOI: 10.1146/annurev-ento-031616-035509] [Citation(s) in RCA: 245] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Entomopathogenic fungi play a pivotal role in the regulation of insect populations in nature, and representative species have been developed as promising environmentally friendly mycoinsecticides. Recent advances in the genome biology of insect pathogenic fungi have revealed genomic features associated with fungal adaptation to insect hosts and different host ranges, as well as the evolutionary relationships between insect and noninsect pathogens. By using species in the Beauveria and Metarhizium genera as models, molecular biology studies have revealed the genes that function in fungus-insect interactions and thereby contribute to fungal virulence. Taken together with efforts toward genetic improvement of fungal virulence and stress resistance, knowledge of entomopathogenic fungi will potentiate cost-effective applications of mycoinsecticides for pest control in the field. Relative to our advanced insights into the mechanisms of fungal pathogenesis in plants and humans, future studies will be necessary to unravel the gene-for-gene relationships in fungus-insect interactive models.
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Affiliation(s)
- Chengshu Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; ,
| | - Sibao Wang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China; ,
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24
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Xu YJ, Luo F, Li B, Shang Y, Wang C. Metabolic Conservation and Diversification of Metarhizium Species Correlate with Fungal Host-Specificity. Front Microbiol 2016; 7:2020. [PMID: 28018335 PMCID: PMC5159617 DOI: 10.3389/fmicb.2016.02020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 12/02/2016] [Indexed: 01/14/2023] Open
Abstract
The ascomycete genus Metarhizium contains several species of insect pathogenic fungi ranging from specialists with narrow host ranges to generalists that can infect diverse invertebrates. Genetic and metabolic conservations and diversifications of Metarhizium species are not well understood. In this study, using the genome information of seven Metarhizium species, we performed a comparative analysis of gene clusters involved in secondary metabolisms (SMs) in these species. The results revealed that the generalist species contain more SM gene clusters than the specialists, and that both conserved and divergent evolutions may have occurred in SM genes during fungal speciation. In particular, the loss/gain events, as well as gene mutagenesis, are evident for the gene cluster responsible for the biosynthesis of non-ribosomal cyclopeptide destruxins. The presence of conserved SM gene clusters in Metarhizium and other divergently evolved insect pathogenic fungi implies their link to fungal entomopathogenicity. Mass spectrometry based metabolomic analyses were also conducted to investigate the chemical diversities of seven Metarhizium species. Consistent with the evolutionary relationships of SM genes among the seven species, significant differences are observed in fungal metabolic profiles, whether the same or different metabolites are produced in different species. Clustering analysis based on the metabolome data revealed that Metarhizium species could be grouped based on their association to fungal host specificity. Our metabolomics-based methods also facilitate the identification of bioactive metabolites that have not been reported previously in Metarhizium. The results of this study will benefit future investigations of the chemical biology of insect-fungal interactions.
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Affiliation(s)
- Yong-Jiang Xu
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Feifei Luo
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Bing Li
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Yanfang Shang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
| | - Chengshu Wang
- CAS Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences Shanghai, China
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Disruptions of the genes involved in lysine biosynthesis, iron acquisition, and secondary metabolisms affect virulence and fitness in Metarhizium robertsii. Fungal Genet Biol 2016; 98:23-34. [PMID: 27876630 DOI: 10.1016/j.fgb.2016.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 11/14/2016] [Accepted: 11/18/2016] [Indexed: 01/07/2023]
Abstract
Based on genomic analysis, polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) pathways account for biosynthesis of the majority of the secondary metabolites produced by the entomopathogenic fungus Metarhizium robertsii. To evaluate the contribution of these pathways to M. robertsii fitness and/or virulence, mutants deleted for mrpptA, the Sfp-type 4' phosphopantetheinyl transferase gene required for their activation were generated. ΔmrpptA strains were deficient in PKS and NRPS activity resulting in colonies that lacked the typical green pigment and failed to produce the nonribosomal peptides (destruxins, serinocylins, and the siderophores ferricrocin and metachelins) as well as the hybrid polyketide-peptides (NG-39x) that are all produced by the wild type (WT) M. robertsii. The ΔmrpptA colonies were also auxotrophic for lysine. Two other mutant strains were generated: ΔmraarA, in which the α-aminoadipate reductase gene critical for lysine biosynthesis was disrupted, and ΔmrsidA, in which the L-ornithine N5-oxygenase gene that is critical for hydroxamate siderophore biosynthesis was disrupted. The phenotypes of these mutants were compared to those of ΔmrpptA to separate effects of the loss of lysine or siderophore production from the overall effect of losing all polyketide and non-ribosomal peptide production. Loss of lysine biosynthesis marginally increased resistance to H2O2 while it had little effect on the sensitivity to the cell wall disruptor sodium dodecyl sulfate (SDS) and no effect on sensitivity to iron deprivation. In contrast, combined loss of metachelin and ferricrocin through the inactivation of mrsidA resulted in mutants that were as hypersensitive or slightly more sensitive to H2O2, iron deprivation, and SDS, and were either identical or marginally higher in ΔmrpptA strains. In contrast to ΔmrpptA, loss of mrsidA did not completely abolish siderophore activity, which suggests the production of one or more non-hydroxamate iron-chelating compounds. Deletion of mrpptA, mrsidA, and mraarA reduced conidium production and conidia of a GFP-tagged ΔmrpptA strain displayed a longer germination delay than WT on insect cuticles, a deficiency that was rescued by lysine supplementation. Compared with WT, ΔmrpptA strains displayed ∼19-fold reduction in virulence against Drosophila suzukii. In contrast, lysine auxotrophy and loss of siderophores accounted for ∼2 and ∼6-fold decreases in virulence, respectively. Deletion of mrpptA had no significant effect on growth inhibition of Bacillus cereus. Our results suggest that PKS and NRPS metabolism plays a significant role in M. robertsii virulence, depresses conidium production, and contributes marginally to resistance to oxidative stress and iron homeostasis, but has no significant antibacterial effect.
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Comparative Proteomic Analysis of Light-Induced Mycelial Brown Film Formation in Lentinula edodes. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5837293. [PMID: 27868065 PMCID: PMC5102706 DOI: 10.1155/2016/5837293] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 09/21/2016] [Indexed: 11/18/2022]
Abstract
Light-induced brown film (BF) formation by the vegetative mycelium of Lentinula edodes is important for ensuring the quantity and quality of this edible mushroom. Nevertheless, the molecular mechanism underlying this phenotype is still unclear. In this study, a comparative proteomic analysis of mycelial BF formation in L. edodes was performed. Seventy-three protein spots with at least a twofold difference in abundance on two-dimensional electrophoresis (2DE) maps were observed, and 52 of them were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF/MS). These proteins were classified into the following functional categories: small molecule metabolic processes (39%), response to oxidative stress (5%), and organic substance catabolic processes (5%), followed by oxidation-reduction processes (3%), single-organism catabolic processes (3%), positive regulation of protein complex assembly (3%), and protein metabolic processes (3%). Interestingly, four of the proteins that were upregulated in response to light exposure were nucleoside diphosphate kinases. To our knowledge, this is the first proteomic analysis of the mechanism of BF formation in L. edodes. Our data will provide a foundation for future detailed investigations of the proteins linked to BF formation.
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Sbaraini N, Guedes RLM, Andreis FC, Junges Â, de Morais GL, Vainstein MH, de Vasconcelos ATR, Schrank A. Secondary metabolite gene clusters in the entomopathogen fungus Metarhizium anisopliae: genome identification and patterns of expression in a cuticle infection model. BMC Genomics 2016; 17:736. [PMID: 27801295 PMCID: PMC5088523 DOI: 10.1186/s12864-016-3067-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background The described species from the Metarhizium genus are cosmopolitan fungi that infect arthropod hosts. Interestingly, while some species infect a wide range of hosts (host-generalists), other species infect only a few arthropods (host-specialists). This singular evolutionary trait permits unique comparisons to determine how pathogens and virulence determinants emerge. Among the several virulence determinants that have been described, secondary metabolites (SMs) are suggested to play essential roles during fungal infection. Despite progress in the study of pathogen-host relationships, the majority of genes related to SM production in Metarhizium spp. are uncharacterized, and little is known about their genomic organization, expression and regulation. To better understand how infection conditions may affect SM production in Metarhizium anisopliae, we have performed a deep survey and description of SM biosynthetic gene clusters (BGCs) in M. anisopliae, analyzed RNA-seq data from fungi grown on cattle-tick cuticles, evaluated the differential expression of BGCs, and assessed conservation among the Metarhizium genus. Furthermore, our analysis extended to the construction of a phylogeny for the following three BGCs: a tropolone/citrinin-related compound (MaPKS1), a pseurotin-related compound (MaNRPS-PKS2), and a putative helvolic acid (MaTERP1). Results Among 73 BGCs identified in M. anisopliae, 20 % were up-regulated during initial tick cuticle infection and presumably possess virulence-related roles. These up-regulated BGCs include known clusters, such as destruxin, NG39x and ferricrocin, together with putative helvolic acid and, pseurotin and tropolone/citrinin-related compound clusters as well as uncharacterized clusters. Furthermore, several previously characterized and putative BGCs were silent or down-regulated in initial infection conditions, indicating minor participation over the course of infection. Interestingly, several up-regulated BGCs were not conserved in host-specialist species from the Metarhizium genus, indicating differences in the metabolic strategies employed by generalist and specialist species to overcome and kill their host. These differences in metabolic potential may have been partially shaped by horizontal gene transfer (HGT) events, as our phylogenetic analysis provided evidence that the putative helvolic acid cluster in Metarhizium spp. originated from an HGT event. Conclusions Several unknown BGCs are described, and aspects of their organization, regulation and origin are discussed, providing further support for the impact of SM on the Metarhizium genus lifestyle and infection process. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3067-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nicolau Sbaraini
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rafael Lucas Muniz Guedes
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Laboratório Nacional de Computação Científica, LNCC, Petrópolis, RJ, Brazil
| | - Fábio Carrer Andreis
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ângela Junges
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Guilherme Loss de Morais
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.,Laboratório Nacional de Computação Científica, LNCC, Petrópolis, RJ, Brazil
| | - Marilene Henning Vainstein
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Ana Tereza Ribeiro de Vasconcelos
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil.,Laboratório Nacional de Computação Científica, LNCC, Petrópolis, RJ, Brazil
| | - Augusto Schrank
- Rede Avançada em Biologia Computacional, RABICÓ, Petrópolis, RJ, Brazil. .,Centro de Biotecnologia, Programa de Pós-graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Wang JB, St Leger RJ, Wang C. Advances in Genomics of Entomopathogenic Fungi. ADVANCES IN GENETICS 2016; 94:67-105. [PMID: 27131323 DOI: 10.1016/bs.adgen.2016.01.002] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Fungi are the commonest pathogens of insects and crucial regulators of insect populations. The rapid advance of genome technologies has revolutionized our understanding of entomopathogenic fungi with multiple Metarhizium spp. sequenced, as well as Beauveria bassiana, Cordyceps militaris, and Ophiocordyceps sinensis among others. Phylogenomic analysis suggests that the ancestors of many of these fungi were plant endophytes or pathogens, with entomopathogenicity being an acquired characteristic. These fungi now occupy a wide range of habitats and hosts, and their genomes have provided a wealth of information on the evolution of virulence-related characteristics, as well as the protein families and genomic structure associated with ecological and econutritional heterogeneity, genome evolution, and host range diversification. In particular, their evolutionary transition from plant pathogens or endophytes to insect pathogens provides a novel perspective on how new functional mechanisms important for host switching and virulence are acquired. Importantly, genomic resources have helped make entomopathogenic fungi ideal model systems for answering basic questions in parasitology, entomology, and speciation. At the same time, identifying the selective forces that act upon entomopathogen fitness traits could underpin both the development of new mycoinsecticides and further our understanding of the natural roles of these fungi in nature. These roles frequently include mutualistic relationships with plants. Genomics has also facilitated the rapid identification of genes encoding biologically useful molecules, with implications for the development of pharmaceuticals and the use of these fungi as bioreactors.
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Affiliation(s)
- J B Wang
- University of Maryland, College Park, MD, United States
| | - R J St Leger
- University of Maryland, College Park, MD, United States
| | - C Wang
- Chinese Academy of Sciences, Shanghai, China
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Donzelli B, Krasnoff S. Molecular Genetics of Secondary Chemistry in Metarhizium Fungi. GENETICS AND MOLECULAR BIOLOGY OF ENTOMOPATHOGENIC FUNGI 2016; 94:365-436. [DOI: 10.1016/bs.adgen.2016.01.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Braga GUL, Rangel DEN, Fernandes ÉKK, Flint SD, Roberts DW. Molecular and physiological effects of environmental UV radiation on fungal conidia. Curr Genet 2015; 61:405-25. [PMID: 25824285 DOI: 10.1007/s00294-015-0483-0] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 03/05/2015] [Accepted: 03/13/2015] [Indexed: 02/07/2023]
Abstract
Conidia are specialized structures produced at the end of the asexual life cycle of most filamentous fungi. They are responsible for fungal dispersal and environmental persistence. In pathogenic species, they are also involved in host recognition and infection. Conidial production, survival, dispersal, germination, pathogenicity and virulence can be strongly influenced by exposure to solar radiation, although its effects are diverse and often species dependent. UV radiation is the most harmful and mutagenic waveband of the solar spectrum. Direct exposure to solar radiation for a few hours can kill conidia of most fungal species. Conidia are killed both by solar UV-A and UV-B radiation. In addition to killing conidia, which limits the size of the fungal population and its dispersion, exposures to sublethal doses of UV radiation can reduce conidial germination speed and virulence. The focus of this review is to provide an overview of the effects of solar radiation on conidia and on the major systems involved in protection from and repair of damage induced by solar UV radiation. The efforts that have been made to obtain strains of fungi of interest such as entomopathogens more tolerant to solar radiation will also be reviewed.
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Affiliation(s)
- Gilberto U L Braga
- Departamento de Análises Clínicas, Toxicológicas E Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil,
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MrSkn7 controls sporulation, cell wall integrity, autolysis, and virulence in Metarhizium robertsii. EUKARYOTIC CELL 2015; 14:396-405. [PMID: 25710964 DOI: 10.1128/ec.00266-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 02/16/2015] [Indexed: 01/06/2023]
Abstract
Two-component signaling pathways generally include sensor histidine kinases and response regulators. We identified an ortholog of the response regulator protein Skn7 in the insect-pathogenic fungus Metarhizium robertsii, which we named MrSkn7. Gene deletion assays and functional characterizations indicated that MrSkn7 functions as a transcription factor. The MrSkn7 null mutant of M. robertsii lost the ability to sporulate and had defects in cell wall biosynthesis but was not sensitive to oxidative and osmotic stresses compared to the wild type. However, the mutant was able to produce spores under salt stress. Insect bioassays using these spores showed that the virulence of the mutant was significantly impaired compared to that of the wild type due to the failures to form the infection structure appressorium and evade host immunity. In particular, deletion of MrSkn7 triggered cell autolysis with typical features such as cell vacuolization, downregulation of repressor genes, and upregulation of autolysis-related genes such as extracellular chitinases and proteases. Promoter binding assays confirmed that MrSkn7 could directly or indirectly control different putative target genes. Taken together, the results of this study help us understand the functional divergence of Skn7 orthologs as well as the mechanisms underlying the development and control of virulence in insect-pathogenic fungi.
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Huang W, Shang Y, Chen P, Cen K, Wang C. Basic leucine zipper (bZIP) domain transcription factor MBZ1 regulates cell wall integrity, spore adherence, and virulence in Metarhizium robertsii. J Biol Chem 2015; 290:8218-31. [PMID: 25673695 DOI: 10.1074/jbc.m114.630939] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transcription factors (TFs) containing the basic leucine zipper (bZIP) domain are widely distributed in eukaryotes and display an array of distinct functions. In this study, a bZIP-type TF gene (MBZ1) was deleted and functionally characterized in the insect pathogenic fungus Metarhizium robertsii. The deletion mutant (ΔMBZ1) showed defects in cell wall integrity, adhesion to hydrophobic surfaces, and topical infection of insects. Relative to the WT, ΔMBZ1 was also impaired in growth and conidiogenesis. Examination of putative target gene expression indicated that the genes involved in chitin biosynthesis were differentially transcribed in ΔMBZ1 compared with the WT, which led to the accumulation of a higher level of chitin in mutant cell walls. MBZ1 exhibited negative regulation of subtilisin proteases, but positive control of an adhesin gene, which is consistent with the observation of effects on cell autolysis and a reduction in spore adherence to hydrophobic surfaces in ΔMBZ1. Promoter binding assays indicated that MBZ1 can bind to different target genes and suggested the possibility of heterodimer formation to increase the diversity of the MBZ1 regulatory network. The results of this study advance our understanding of the divergence of bZIP-type TFs at both intra- and interspecific levels.
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Affiliation(s)
- Wei Huang
- From the Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Yanfang Shang
- From the Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Peilin Chen
- From the Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Kai Cen
- From the Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Chengshu Wang
- From the Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
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