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Xu L, Wang H, Zhang C, Wang J, Chen A, Chen Y, Ma Z. System-wide characterization of subtilases reveals that subtilisin-like protease FgPrb1 of Fusarium graminearum regulates fungal development and virulence. Fungal Genet Biol 2020; 144:103449. [PMID: 32890707 DOI: 10.1016/j.fgb.2020.103449] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/30/2022]
Abstract
Subtilases represent the second largest subfamily of serine proteases, and are important for various biological processes. However, the biological function of subtilases has not been systematically characterized in plant pathogens. In present study, 32 subtilases were identified in the genome of wheat scab fungus Fusarium graminearum, a devastating cereal plant pathogen. Deletion mutants of each subtilase were obtained and functionally characterized. Among them, the deletion of FgPrb1 resulted in greatly reduced virulence of F. graminearum. The regulatory mechanisms of FgPrb1 in virulence were investigated in details. Our results showed that the loss of FgPrb1 led to defects in deoxynivalenol (DON) production, responses to environmental stimuli, and lipid metabolism. Additionally, we found that FgPrb1 was involved in autophagy regulation. Taken together, the systematic functional characterization of subtilases showed that the FgPrb1 of F. graminearum is critical for plant infection by regulating multiple different cellular processes.
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Affiliation(s)
- Luona Xu
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
| | - Hongkai Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
| | - Chengqi Zhang
- Department of Plant Pathology, College of Plant Protection, Anhui Agricultural University, Hefei 230036, China
| | - Jinli Wang
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
| | - Ahai Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China.
| | - Yun Chen
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
| | - Zhonghua Ma
- State Key Laboratory of Rice Biology, Institute of Biotechnology, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Zhejiang University, Hangzhou 310058, China
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Yang K, Liu Y, Wang S, Wu L, Xie R, Lan H, Fasoyin OE, Wang Y, Wang S. Cyclase-Associated Protein Cap with Multiple Domains Contributes to Mycotoxin Biosynthesis and Fungal Virulence in Aspergillus flavus. J Agric Food Chem 2019; 67:4200-4213. [PMID: 30916945 DOI: 10.1021/acs.jafc.8b07115] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In Aspergillus, the cyclic adenosine monophosphate (cAMP) signaling modulates asexual development and mycotoxin biosynthesis. Here, we characterize the cyclase-associated protein Cap in the pathogenic fungus Aspergillus flauvs. The cap disruption mutant exhibited dramatic reduction in hyphal growth, conidiation, and spore germination, while an enhanced production of the sclerotia was observed in this mutant. Importantly, the cap gene was found to be important for mycotoxin biosynthesis and virulence. The domain deletion study demonstrated that each domain played an important role for the Cap protein in regulating cAMP/protein kinase A (PKA) signaling, while only P1 and CARP domains were essential for the full function of Cap. The phosphorylation of Cap at S35 was identified in A. flavus, which was found to play a negligible role for the function of Cap. Overall, our results indicated that Cap with multiple domains engages in mycotoxin production and fungal pathogenicity, which could be designed as potential control targets for preventing this fungal pathogen.
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Affiliation(s)
- Kunlong Yang
- 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 , Fujian 350002 , People's Republic of China
- School of Life Science , Jiangsu Normal University , Xuzhou , Jiangsu 221116 , People's Republic of China
| | - Yinghang Liu
- 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 , Fujian 350002 , People's Republic of China
- State Key Laboratory of Microbial Technology , Shandong University , Jinan , Shandong 250100 , People's Republic of China
| | - Sen 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 , Fujian 350002 , People's Republic of China
| | - Lianghuan Wu
- 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 , Fujian 350002 , People's Republic of China
| | - Rui Xie
- 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 , Fujian 350002 , People's Republic of China
| | - Huahui Lan
- 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 , Fujian 350002 , People's Republic of China
| | - Opemipo Esther Fasoyin
- Biotechnology Research Institute , Chinese Academy of Agricultural Sciences , 12 Zhongguancun South Street , Beijing 100081 , People's Republic of China
| | - Yu 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 , Fujian 350002 , 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 , Fujian 350002 , People's Republic of China
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Ren W, Tao J, Shi D, Chen W, Chen C. Involvement of a dihydrodipicolinate synthase gene (FaDHDPS1) in fungal development, pathogenesis and stress responses in Fusarium asiaticum. BMC Microbiol 2018; 18:128. [PMID: 30290767 PMCID: PMC6173861 DOI: 10.1186/s12866-018-1268-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 09/27/2018] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Dihydrodipicolinate synthase (DHDPS) is an allosteric enzyme, which catalyzes the first unique step of lysine biosynthesis in prokaryotes, higher plants and some fungi. To date, the biological roles of DHDPS in filamentous fungi are poorly understood. RESULTS In this study, on the basis of comparative genome resequencing, a DHDPS gene was found to be specific in Fusarium asiaticum, named FaDHDPS1, which showed high amino acid identity to that of entomopathogenic fungus. Subcellular localization of the FaDHDPS1-GFP fusion protein was mainly concentrated in the cytoplasm of conidia and dispersed in the cytoplasm during conidial germination. To reveal the biological functions, both deletion and complementation mutants of FaDHDPS1 were generated. The results showed that the FaDHDPS1 deletion mutant was defective in conidiation, virulence and DON biosynthesis. In addition, deletion of FaDHDPS1 resulted in tolerance to sodium pyruvate, lysine, low temperature and Congo red. CONCLUSION Results of this study indicate that FaDHDPS1 plays an important role in the regulation of vegetative differentiation, pathogenesis and adaption to multiple stresses in F. asiaticum.
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Affiliation(s)
- Weichao Ren
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095 Jiangsu China
| | - Jiting Tao
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095 Jiangsu China
| | - Dongya Shi
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095 Jiangsu China
| | - Wenchan Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095 Jiangsu China
| | - Changjun Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095 Jiangsu China
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Luo Z, Zhang T, Liu P, Bai Y, Chen Q, Zhang Y, Keyhani NO. The Beauveria bassiana Gas3 β-Glucanosyltransferase Contributes to Fungal Adaptation to Extreme Alkaline Conditions. Appl Environ Microbiol 2018; 84:e01086-18. [PMID: 29802184 PMCID: PMC6052264 DOI: 10.1128/aem.01086-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Accepted: 05/17/2018] [Indexed: 12/20/2022] Open
Abstract
Fungal β-1,3-glucanosyltransferases are cell wall-remodeling enzymes implicated in stress response, cell wall integrity, and virulence, with most fungal genomes containing multiple members. The insect-pathogenic fungus Beauveria bassiana displays robust growth over a wide pH range (pH 4 to 10). A random insertion mutant library screening for increased sensitivity to alkaline (pH 10) growth conditions resulted in the identification and mapping of a mutant to a β-1,3-glucanosyltransferase gene (Bbgas3). Bbgas3 expression was pH dependent and regulated by the PacC transcription factor, which activates genes in response to neutral/alkaline growth conditions. Targeted gene knockout of Bbgas3 resulted in reduced growth under alkaline conditions, with only minor effects of increased sensitivity to cell wall stress (Congo red and calcofluor white) and no significant effects on fungal sensitivity to oxidative or osmotic stress. The cell walls of ΔBbgas3 aerial conidia were thinner than those of the wild-type and complemented strains in response to alkaline conditions, and β-1,3-glucan antibody and lectin staining revealed alterations in cell surface carbohydrate epitopes. The ΔBbgas3 mutant displayed alterations in cell wall chitin and carbohydrate content in response to alkaline pH. Insect bioassays revealed impaired virulence for the ΔBbgas3 mutant depending upon the pH of the media on which the conidia were grown and harvested. Unexpectedly, a decreased median lethal time to kill (LT50, i.e., increased virulence) was seen for the mutant using intrahemocoel injection assays using conidia grown at acidic pH (5.6). These data show that BbGas3 acts as a pH-responsive cell wall-remodeling enzyme involved in resistance to extreme pH (>9).IMPORTANCE Little is known about adaptations required for growth at high (>9) pH. Here, we show that a specific fungal membrane-remodeling β-1,3-glucanosyltransferase gene (Bbgas3) regulated by the pH-responsive PacC transcription factor forms a critical aspect of the ability of the insect-pathogenic fungus Beauveria bassiana to grow at extreme pH. The loss of Bbgas3 resulted in a unique decreased ability to grow at high pH, with little to no effects seen with respect to other stress conditions, i.e., cell wall integrity and osmotic and oxidative stress. However, pH-dependent alternations in cell wall properties and virulence were noted for the ΔBbgas3 mutant. These data provide a mechanistic insight into the importance of the specific cell wall structure required to stabilize the cell at high pH and link it to the PacC/Pal/Rim pH-sensing and regulatory system.
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Affiliation(s)
- Zhibing Luo
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Tongbing Zhang
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Pengfei Liu
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Yuting Bai
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Qiyan Chen
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Yongjun Zhang
- Academy of Agricultural Sciences, Southwest University, Chongqing, People's Republic of China
- Biotechnology Research Center, Southwest University, Chongqing, People's Republic of China
| | - Nemat O Keyhani
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
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Lee Y, Son H, Shin JY, Choi GJ, Lee Y. Genome-wide functional characterization of putative peroxidases in the head blight fungus Fusarium graminearum. Mol Plant Pathol 2018; 19:715-730. [PMID: 28387997 PMCID: PMC6638050 DOI: 10.1111/mpp.12557] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/28/2017] [Accepted: 04/01/2017] [Indexed: 06/01/2023]
Abstract
Reactive oxygen species (ROS) are associated with various developmental processes and host-pathogen interactions in pathogenic fungi. Peroxidases are a group of ROS-detoxifying enzymes that are involved in the oxidative stress response and in a variety of physiological processes. In this study, we performed a genome-wide functional characterization of putative peroxidase genes in Fusarium graminearum, a head blight pathogen of cereal crops. We identified 31 putative peroxidase genes and generated deletion mutants for these genes. Twenty-six of the deletion mutants showed developmental phenotypes indistinguishable from that of the wild-type, and five deletion mutants exhibited phenotypic changes in at least one phenotypic category. Four deletion mutants, fca6, fca7, fpx1 and fpx15, showed increased sensitivity to extracellular H2 O2 . Deletion mutants of FCA7 also exhibited reduced virulence and increased trichothecene production compared with those of the wild-type strain, suggesting that Fca7 may play an important role in the host-pathogen interaction in F. graminearum. To identify the transcription factors (TFs) regulating FCA6, FCA7, FPX1 and FPX15 in response to oxidative stress, we screened an F. graminearum TF mutant library for growth in the presence of H2 O2 and found that multiple TFs co-regulated the expression of FCA7 under oxidative stress conditions. These results demonstrate that a complex network of transcriptional regulators of antioxidant genes is involved in oxidative stress responses in this fungus. Moreover, our study provides insights into the roles of peroxidases in developmental processes and host-pathogen interactions in plant-pathogenic fungi.
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Affiliation(s)
- Yoonji Lee
- Department of Agricultural BiotechnologySeoul National UniversitySeoul08826South Korea
| | - Hokyoung Son
- Center for Food and BioconvergenceSeoul National UniversitySeoul08826South Korea
| | - Ji Young Shin
- Department of Agricultural BiotechnologySeoul National UniversitySeoul08826South Korea
| | - Gyung Ja Choi
- Eco‐friendly New Materials Research Group, Research Center for Biobased Chemistry, Division of Convergence ChemistryKorea Research Institute of Chemical TechnologyDaejeon34114South Korea
| | - Yin‐Won Lee
- Department of Agricultural BiotechnologySeoul National UniversitySeoul08826South Korea
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Cohrs KC, Schumacher J. The Two Cryptochrome/Photolyase Family Proteins Fulfill Distinct Roles in DNA Photorepair and Regulation of Conidiation in the Gray Mold Fungus Botrytis cinerea. Appl Environ Microbiol 2017; 83:e00812-17. [PMID: 28667107 PMCID: PMC5561282 DOI: 10.1128/aem.00812-17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 06/24/2017] [Indexed: 12/13/2022] Open
Abstract
The plant-pathogenic leotiomycete Botrytis cinerea is known for the strict regulation of its asexual differentiation programs by environmental light conditions. Sclerotia are formed in constant darkness; black/near-UV (NUV) light induces conidiation; and blue light represses both differentiation programs. Sensing of black/NUV light is attributed to proteins of the cryptochrome/photolyase family (CPF). To elucidate the molecular basis of the photoinduction of conidiation, we functionally characterized the two CPF proteins encoded in the genome of B. cinerea as putative positive-acting components. B. cinerea CRY1 (BcCRY1), a cyclobutane pyrimidine dimer (CPD) photolyase, acts as the major enzyme of light-driven DNA repair (photoreactivation) and has no obvious role in signaling. In contrast, BcCRY2, belonging to the cry-DASH proteins, is dispensable for photorepair but performs regulatory functions by repressing conidiation in white and especially black/NUV light. The transcription of bccry1 and bccry2 is induced by light in a White Collar complex (WCC)-dependent manner, but neither light nor the WCC is essential for the repression of conidiation through BcCRY2 when bccry2 is constitutively expressed. Further, BcCRY2 affects the transcript levels of both WCC-induced and WCC-repressed genes, suggesting a signaling function downstream of the WCC. Since both CPF proteins are dispensable for photoinduction by black/NUV light, the origin of this effect remains elusive and may be connected to a yet unknown UV-light-responsive system.IMPORTANCEBotrytis cinerea is an economically important plant pathogen that causes gray mold diseases in a wide variety of plant species, including high-value crops and ornamental flowers. The spread of disease in the field relies on the formation of conidia, a process that is regulated by different light qualities. While this feature has been known for a long time, we are just starting to understand the underlying molecular mechanisms. Conidiation in B. cinerea is induced by black/near-UV light, whose sensing is attributed to the action of cryptochrome/photolyase family (CPF) proteins. Here we report on the distinct functions of two CPF proteins in the photoresponse of B. cinerea While BcCRY1 acts as the major photolyase in photoprotection, BcCRY2 acts as a cryptochrome with a signaling function in regulating photomorphogenesis (repression of conidiation).
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Affiliation(s)
- Kim C Cohrs
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität (WWU), Münster, Germany
| | - Julia Schumacher
- Institut für Biologie und Biotechnologie der Pflanzen (IBBP), Westfälische Wilhelms-Universität (WWU), Münster, Germany
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Galhano R, Illana A, Ryder LS, Rodríguez-Romero J, Demuez M, Badaruddin M, Martinez-Rocha AL, Soanes DM, Studholme DJ, Talbot NJ, Sesma A. Tpc1 is an important Zn(II)2Cys6 transcriptional regulator required for polarized growth and virulence in the rice blast fungus. PLoS Pathog 2017; 13:e1006516. [PMID: 28742127 PMCID: PMC5542705 DOI: 10.1371/journal.ppat.1006516] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 08/03/2017] [Accepted: 07/06/2017] [Indexed: 01/05/2023] Open
Abstract
The establishment of polarity is a critical process in pathogenic fungi, mediating infection-related morphogenesis and host tissue invasion. Here, we report the identification of TPC1 (Transcription factor for Polarity Control 1), which regulates invasive polarized growth in the rice blast fungus Magnaporthe oryzae. TPC1 encodes a putative transcription factor of the fungal Zn(II)2Cys6 family, exclusive to filamentous fungi. Tpc1-deficient mutants show severe defects in conidiogenesis, infection-associated autophagy, glycogen and lipid metabolism, and plant tissue colonisation. By tracking actin-binding proteins, septin-5 and autophagosome components, we show that Tpc1 regulates cytoskeletal dynamics and infection-associated autophagy during appressorium-mediated plant penetration. We found that Tpc1 interacts with Mst12 and modulates its DNA-binding activity, while Tpc1 nuclear localisation also depends on the MAP kinase Pmk1, consistent with the involvement of Tpc1 in this signalling pathway, which is critical for appressorium development. Importantly, Tpc1 directly regulates NOXD expression, the p22phox subunit of the fungal NADPH oxidase complex via an interaction with Mst12. Tpc1 therefore controls spatial and temporal regulation of cortical F-actin through regulation of the NADPH oxidase complex during appressorium re-polarisation. Consequently, Tpc1 is a core developmental regulator in filamentous fungi, linking the regulated synthesis of reactive oxygen species and the Pmk1 pathway, with polarity control during host invasion. Cellular polarity is an intrinsic feature of filamentous fungal growth and pathogenesis. In this study, we identified a gene required for fungal polar growth and virulence in the rice blast fungus Magnaporthe oryzae. This gene has been named TPC1 (Transcription factor for Polarity Control 1). The Tpc1 protein belongs to the fungal Zn(II)2Cys6 binuclear cluster family. This DNA-binding motif is present exclusively in the fungal kingdom. We have characterised defects associated with lack of Tpc1 in M. oryzae. We show that Tpc1 is involved in polarised growth and virulence. The M. oryzae Δtpc1 mutant shows a delay in glycogen and lipid metabolism, and infection-associated autophagy–processes that regulate appressorium-mediated M. oryzae plant infection. The saprophytic fungus Neurospora crassa contains a Tpc1 homolog (NcTpc1) involved in vegetative growth and sustained tip elongation, suggesting that Tpc1-like proteins act as core regulators of polarised growth and development in filamentous fungi. A comparative transcriptome analysis has allowed us to identify genes regulated by Tpc1 in M. oryzae including NoxD, an important component of the fungal NADPH complex. Significantly, Tpc1 interacts with Mst12, a component of the Pmk1 signalling pathway essential for appressorium development, and modulates Mst12 binding affinity to NOXD promoter region. We conclude that Tpc1 is a key regulator of polarity in M. oryzae that regulates growth, autophagy and septin-mediated reorientation of the F-actin cytoskeleton to facilitate plant cell invasion.
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Affiliation(s)
- Rita Galhano
- Disease & Stress Biology Dept. John Innes Centre, Norwich, United Kingdom
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | - Adriana Illana
- Centre for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Madrid, Spain
- Dept. Biotecnología y Biología Vegetal, UPM, Madrid, Spain
| | - Lauren S. Ryder
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | - Julio Rodríguez-Romero
- Centre for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Madrid, Spain
- Dept. Biotecnología y Biología Vegetal, UPM, Madrid, Spain
| | - Marie Demuez
- Centre for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Madrid, Spain
- Dept. Biotecnología y Biología Vegetal, UPM, Madrid, Spain
| | - Muhammad Badaruddin
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | | | - Darren M. Soanes
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | - David J. Studholme
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | - Nicholas J. Talbot
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter, United Kingdom
| | - Ane Sesma
- Disease & Stress Biology Dept. John Innes Centre, Norwich, United Kingdom
- Centre for Plant Biotechnology and Genomics (CBGP), Universidad Politécnica de Madrid, (UPM) – Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Pozuelo de Alarcón, Madrid, Spain
- Dept. Biotecnología y Biología Vegetal, UPM, Madrid, Spain
- * E-mail:
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Cheng XX, Zhao LH, Klosterman SJ, Feng HJ, Feng ZL, Wei F, Shi YQ, Li ZF, Zhu HQ. The endochitinase VDECH from Verticillium dahliae inhibits spore germination and activates plant defense responses. Plant Sci 2017; 259:12-23. [PMID: 28483050 DOI: 10.1016/j.plantsci.2017.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/01/2017] [Accepted: 03/06/2017] [Indexed: 05/06/2023]
Abstract
Chitinases function in the digestion of chitin molecules, which are present principally in insects and fungi. In plants, chitinase genes play important roles in defense, and their expression can be triggered in response to both biotic and abiotic stresses. In this study, we cloned and characterized an endochitinase (VDECH) from Verticillium dahliae, strain Vd080. The VDECH coding region consists of 1845bp with two exons and one 54bp intron, encoding a 615 amino acid protein with the predicted molecular weight (MW) of 63.9kDa. The VDECH cDNA without signal peptide-encoding region was introduced into pCold-TF vector and the recombinant protein HIS-VDECH with a predicted MW of ∼114kDa was expressed. HIS-VDECH showed high tolerance to extreme temperature, exhibiting efficient chitinolytic activity at 50°C. In addition, VDECH triggered typical plant defense responses, including a hypersensitive response, oxidative burst, and elicited increased expression of defense-related genes in both Arabidopsis and cotton. VDECH-treatment of the conidial spores of V. dahliae and Fusarium oxysporum resulted in marked reductions in the germination of these spores in both fungi. After 36h of incubation with VDECH, the inhibition rate of germination was recorded at 99.57% for V. dahliae, and 96.89% for F. oxysporum. These results provide evidence that VDECH is recognized by the plant to elicit defense responses, and also that VDECH is an effective inhibitor of conidia germination, both of which may be exploited for disease control.
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Affiliation(s)
- Xiao-Xiao Cheng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | - Li-Hong Zhao
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | | | - Hong-Jie Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | - Zi-Li Feng
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | - Feng Wei
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | - Yong-Qiang Shi
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China
| | - Zhi-Fang Li
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China.
| | - He-Qin Zhu
- State Key Laboratory of Cotton Biology, Institute of Cotton Research of Chinese Academy of Agricultural Sciences, Anyang, Henan, 455000, China.
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Song TY, Xu ZF, Chen YH, Ding QY, Sun YR, Miao Y, Zhang KQ, Niu XM. Potent Nematicidal Activity and New Hybrid Metabolite Production by Disruption of a Cytochrome P450 Gene Involved in the Biosynthesis of Morphological Regulatory Arthrosporols in Nematode-Trapping Fungus Arthrobotrys oligospora. J Agric Food Chem 2017; 65:4111-4120. [PMID: 28475838 DOI: 10.1021/acs.jafc.7b01290] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Types of polyketide synthase-terpenoid synthase (PKS-TPS) hybrid metabolites, including arthrosporols with significant morphological regulatory activity, have been elucidated from nematode-trapping fungus Arthrobotrys oligospora. A previous study suggested that the gene cluster AOL_s00215 in A. oligospora was involved in the production of arthrosporols. Here, we report that disruption of one cytochrome P450 monooxygenase gene AOL_s00215g280 in the cluster resulted in significant phenotypic difference and much aerial hyphae. A further bioassay indicated that the mutant showed a dramatic decrease in the conidial formation but developed numerous traps and killed 85% nematodes within 6 h in contact with prey, in sharp contrast to the wild-type strain with no obvious response. Chemical investigation revealed huge accumulation of three new PKS-TPS epoxycyclohexone derivatives with different oxygenated patterns around the epoxycyclohexone moiety and the absence of arthrosporols in the cultural broth of the mutant ΔAOL_s00215g280. These findings suggested that a study on the biosynthetic pathway for morphological regulatory metabolites in nematode-trapping fungus would provide an efficient way to develop new fungal biocontrol agents.
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Affiliation(s)
- Tian-Yang Song
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Zi-Fei Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Yong-Hong Chen
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Qiu-Yan Ding
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Yu-Rong Sun
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Yang Miao
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
| | - Xue-Mei Niu
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Key Laboratory for Microbial Resources of the Ministry of Education, School of Life Science, Yunnan University , Kunming, Yunnan 650091, People's Republic of China
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Salmela A, Lappalainen V, Reponen T, Pasanen P. Retention of fungal enzyme activity in environmental liquid and filter samples. Environ Sci Process Impacts 2017; 19:134-140. [PMID: 28079907 DOI: 10.1039/c6em00554c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Fungal biomass can be determined by measuring the beta-N-acetylhexos-aminidase (NAHA) enzyme activity. NAHA, an enzyme present in fungal mycelium and spores, has been detected in inactive, dormant and non-viable cells. Very little information is available on the enzyme activity of different species or retention of the activity under various storage conditions. This study used fluorometry to evaluate the enzyme activity of liquid and filter samples containing spores of four fungal species from genera Penicillium, Cladosporium, Aspergillus, and Acremonium. When fungal spores were stored on a filter, enzyme activity was more stable than when the spores were maintained in suspension for one year. The enzyme activity in suspension samples increased with most of the differences detected between the values at the baseline and 12 months being statistically significant. The results indicate that enzyme activity varies between species. Cladosporium spores had highest NAHA content per spore, whereas Acremonium did not exhibit any detectable enzyme activity even when viability was detected. The results indicated that samples should be stored as dry filter samples.
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Affiliation(s)
- A Salmela
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - V Lappalainen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - T Reponen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland. and Department of Environmental Health, University of Cincinnati, P.O. Box 670056, Cincinnati, OH 45267-0056, USA
| | - P Pasanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
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Kryukov VY, Rotskaya UN, Yaroslavtseva ON, Elisaphenko EA, Duisembekov BA, Glupov VV. [Phenotypic and genetic changes of entomopathogenic ascomycete Beauveria Bassiana under passaging through various hosts]. Parazitologiia 2017; 51:3-14. [PMID: 29401571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Phenotypic and genetic estimations of entomopathogenic ascomycete B.bassiana (strain Sar-31) after 6-passaging through four hosts were shown. Increasing of virulence, changes in morpho-cultural characteristics and variations in Inter Simple Sequence Repeats (ISSR) assay between initial and reisolated cultures were registered. Six passages of entomopathogenic ascomycete Beauveria bassiana (strain Sar-31) through four hosts (Galleria mellonella, Tenebrio molitor, Leptinotarsa decemlineata, Locusta migratoria) and following estimation of phenotypic and genetic differences of the initial strain and reisolated cultures were conducted. The passaging of strain through certain host led to increasing of virulence for both this host and other test-insects. Unidirectional changes of morpho-cultural characteristics: colonies pigmentation and relief strengthening, increasing of conidia production and lipolytic activity were registered in all passaged cultures. Genetic analysis with 6 ISSR markers revealed variations between initial and reisolated cultures in 3 markers. Taken together, the results of this study help us understand potential ways of fungi strains changes during epizootic process and possibilities of ISSR assay applying for investigation of pathogen transmission.
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Qi Z, Liu M, Dong Y, Yang J, Zhang H, Zheng X, Zhang Z. Orotate phosphoribosyl transferase MoPyr5 is involved in uridine 5'-phosphate synthesis and pathogenesis of Magnaporthe oryzae. Appl Microbiol Biotechnol 2016; 100:3655-66. [PMID: 26810198 DOI: 10.1007/s00253-016-7323-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Revised: 01/08/2016] [Accepted: 01/12/2016] [Indexed: 01/28/2023]
Abstract
Orotate phosphoribosyl transferase (OPRTase) plays an important role in de novo and salvage pathways of nucleotide synthesis and is widely used as a screening marker in genetic transformation. However, the function of OPRTase in plant pathogens remains unclear. In this study, we characterized an ortholog of Saccharomyces cerevisiae Ura5, the OPRTase MoPyr5, from the rice blast fungus Magnaporthe oryzae. Targeted gene disruption revealed that MoPyr5 is required for mycelial growth, appressorial turgor pressure and penetration into plant tissues, invasive hyphal growth, and pathogenicity. Interestingly, the ∆Mopyr5 mutant is also involved in mycelial surface hydrophobicity. Exogenous uridine 5'-phosphate (UMP) restored vegetative growth and rescued the defect in pathogenicity on detached barley and rice leaf sheath. Collectively, our results show that MoPyr5 is an OPRTase for UMP biosynthesis in M. oryzae and indicate that UTP biosynthesis is closely linked with vegetative growth, cell wall integrity, and pathogenicity of fungus. Our results also suggest that UMP biosynthesis would be a good target for the development of novel fungicides against M. oryzae.
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Affiliation(s)
- Zhongqiang Qi
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Muxing Liu
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Yanhan Dong
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Jie Yang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Haifeng Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Xiaobo Zheng
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China
| | - Zhengguang Zhang
- Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, 210095, China.
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Ghassemi S, Lichius A, Bidard F, Lemoine S, Rossignol MN, Herold S, Seidl-Seiboth V, Seiboth B, Espeso EA, Margeot A, Kubicek CP. The ß-importin KAP8 (Pse1/Kap121) is required for nuclear import of the cellulase transcriptional regulator XYR1, asexual sporulation and stress resistance in Trichoderma reesei. Mol Microbiol 2015; 96:405-18. [PMID: 25626518 PMCID: PMC4390390 DOI: 10.1111/mmi.12944] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2015] [Indexed: 11/26/2022]
Abstract
The ascomycete Trichoderma reesei is an industrial producer of cellulolytic and hemicellulolytic enzymes, and serves as a prime model for their genetic regulation. Most of its (hemi-)cellulolytic enzymes are obligatorily dependent on the transcriptional activator XYR1. Here, we investigated the nucleo-cytoplasmic shuttling mechanism that transports XYR1 across the nuclear pore complex. We identified 14 karyopherins in T. reesei, of which eight were predicted to be involved in nuclear import, and produced single gene-deletion mutants of all. We found KAP8, an ortholog of Aspergillus nidulans KapI, and Saccharomyces cerevisiae Kap121/Pse1, to be essential for nuclear recruitment of GFP-XYR1 and cellulase gene expression. Transformation with the native gene rescued this effect. Transcriptomic analyses of Δkap8 revealed that under cellulase-inducing conditions 42 CAZymes, including all cellulases and hemicellulases known to be under XYR1 control, were significantly down-regulated. Δkap8 strains were capable of forming fertile fruiting bodies but exhibited strongly reduced conidiation both in light and darkness, and showed enhanced sensitivity towards abiotic stress, including high osmotic pressure, low pH and high temperature. Together, these data underscore the significance of nuclear import of XYR1 in cellulase and hemicellulase gene regulation in T. reesei, and identify KAP8 as the major karyopherin required for this process.
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Affiliation(s)
- Sara Ghassemi
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
| | - Alexander Lichius
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
| | - Fréderique Bidard
- IFP Energies nouvelles1-4 avenue de Bois-Préau, 92852, Rueil-Malmaison, France
| | - Sophie Lemoine
- Ecole Normale Supérieure, Institut de Biologie de l'ENSIBENS, Plateforme Génomique, Paris, F-75005, France
| | - Marie-Noëlle Rossignol
- Ecole Normale Supérieure, Institut de Biologie de l'ENSIBENS, Plateforme Génomique, Paris, F-75005, France
| | - Silvia Herold
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
| | - Verena Seidl-Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
| | - Bernhard Seiboth
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
- ACIB GmbH, c/o Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Antoine Margeot
- IFP Energies nouvelles1-4 avenue de Bois-Préau, 92852, Rueil-Malmaison, France
| | - Christian P Kubicek
- Research Division Biotechnology and Microbiology, Institute of Chemical EngineeringTU Wien, Vienna, 1060, Austria
- *For correspondence. E-mail ; Tel. (+ 1) 43 1 58801 166085; Fax (+ 1) 43 1 58801 17299
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Ors M, Siah A, Randoux B, Selim S, Couleaud G, Maumene C, Reignault P, Halama P. ASSOCIATION BETWEEN SPORULATION AND CELL-WALL DEGRADING ENZYMES IN THE WHEAT PATHOGEN MYCOSPHAERELLA GRAMINICOLA. Commun Agric Appl Biol Sci 2015; 80:595-598. [PMID: 27141759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mycosphaerella graminicola is a hemibiotrophic fungus that causes Septoria tritici blotch (STB), one of the most serious foliar diseases of wheat. STB can occur with a wide range of disease levels on the host, which depend not only on the pathogenicity of fungal strains, but also on the resistance of host cultivars. Here, we investigated the association between the disease level and fungal cell-wall degrading enzyme and protease activities in three wheat cultivars differing in their resistance levels against M. graminicola. The experiments were carried out in the greenhouse using artificial inoculations with the M. graminicola strain T01193. Disease symptoms scored at 21-day post-inoculation (dpi) were significantly higher on the susceptible and moderately resistant cultivars, Alixan and Premio (48% and 42% of diseased leaf area, respectively), than in the resistant one, Altigo (28% of diseased leaf area). Regarding sporulation, the rate of pycnidial density was significantly higher on Alixan (2.9) compared to Premio and Altigo (1.1 and 1.0, respectively). Further biochemical investigations revealed, by 17 dpi, significant fungal beta-1,4-endoxylanase, beta-1,4-endoglucanase and protease activities, whose amounts increased according to the pycnidial density recorded on the infected leaves. At 21 dpi, the amounts of these activities were significantly higher on Alixan compared to Premio and Altigo (0.36 U/mg, 0.63 U/mg and 2.70 mU/mg total proteins on Alixan, 0.09 U/mg, 0.19 U/mg and 0.72 mU/mg total proteins on Premio and 0.05 U/mg, 0.15 U/mg and 0.52 mU/mg total proteins on Altigo for beta-1,4-endoxylanase, beta-1,4-endoglucanase and protease activities, respectively). These results confirm the importance of CWDE and protease activities in the process of fungal sporulation during the necrotrophic phase of M. graminicola.
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Granato MQ, Massapust PDA, Rozental S, Alviano CS, dos Santos ALS, Kneipp LF. 1,10-phenanthroline inhibits the metallopeptidase secreted by Phialophora verrucosa and modulates its growth, morphology and differentiation. Mycopathologia 2014; 179:231-42. [PMID: 25502596 DOI: 10.1007/s11046-014-9832-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 11/13/2014] [Indexed: 12/31/2022]
Abstract
Phialophora verrucosa is one of the etiologic agents of chromoblastomycosis, a fungal infection that affects cutaneous and subcutaneous tissues. This disease is chronic, recurrent and difficult to treat. Several studies have shown that secreted peptidases by fungi are associated with important pathophysiological processes. Herein, we have identified and partially characterized the peptidase activity secreted by P. verrucosa conidial cells. Using human serum albumin as substrate, the best hydrolysis profile was detected at extreme acidic pH (3.0) and at 37 °C. The enzymatic activity was completely blocked by classical metallopeptidase inhibitors/chelating agents as 1,10-phenanthroline and EGTA. Zinc ions stimulated the metallo-type peptidase activity in a dose-dependent manner. Several proteinaceous substrates were cleaved, in different extension, by the P. verrucosa metallopeptidase activity, including immunoglobulin G, fibrinogen, collagen types I and IV, fibronectin, laminin and keratin; however, mucin and hemoglobin were not susceptible to proteolysis. As metallopeptidases participate in different cellular metabolic pathways in fungal cells, we also tested the influence of 1,10-phenanthroline and EGTA on P. verrucosa development. Contrarily to EGTA, 1,10-phenanthroline inhibited the fungal viability (MIC 0.8 µg/ml), showing fungistatic effect, and induced profound morphological alterations as visualized by transmission electron microscopy. In addition, 1,10-phenanthroline arrested the filamentation process in P. verrucosa. Our results corroborate the supposition that metallopeptidase inhibitors/chelating agents have potential to control crucial biological events in fungal agents of chromoblastomycosis.
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Affiliation(s)
- Marcela Queiroz Granato
- Laboratório de Taxonomia, Bioquímica e Bioprospecção de Fungos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
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Qin J, Huang C, He F, Zhu X, Zhang Y, Kang Z, Guo J. [Function of a calcium-dependent protein kinase gene Pscamk in Puccinia striiformis f. sp. tritici]. Wei Sheng Wu Xue Bao 2014; 54:1296-1303. [PMID: 25752136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To clone calcium-dependent protein kinase gene (camk) from Puccinia striiformis f. sp. tritici (Pst) and analyze its function. METHODS The cDNA full-length of Pscamk was isolated by using reverse transcriptional-PCR (RT-PCR), and gene expression profile at different morphological stages was analyzed via quantitative real-time--PCR (qRT-PCR). Pst urediospores were treated with CaMK suppressor KN-93 and germination rate was investigated. RESULTS A gene cDNA full-length with 1 620 bp was obtained and designated as Pscamk. qRT-PCR analysis showed Pscamk expression was highly induced in the early stages of Pst infection and reached the maximum at 6 h post inoculation (hpi) as 20.74-fold as that in the control (0 hpi). With increasing of the concentration of CaMK suppressor KN-93, germination rate of Pst urediospores was gradually decreased. The germination rate was reduced to 8.02%, only 12% of the control, under 1.4 μmol/L KN-93 treatment at 10 h after incubation at 9 degrees C. CONCLUSION Pscamk might play a role in germination and germ tube elongation of Pst urediospores. This study provides a basis for exploring pathogenesis of calcium signaling pathway during Pst infection.
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Timofeev SA, Sendersky IV, Pavlova OA, Dolgikh VV. [Peculiarities of the expression, structure, and localization of the subtilisin-like protease in the microsporidium Paranosema locustae]. Parazitologiia 2014; 48:337-347. [PMID: 25929105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Peculiarities of the expression, localization, and structure of the subtilisin-like protease from the microsporidium Paranosema locustae, a parasite of the migratory locust and other orthopteran species, are analyzed. Heterologous expression of the microsporidian ferment in the bacterium Escherichia coli allowed obtaining antibodies to the recombinant protein and to start its examination. In spite of the presence of the N-tail signal peptide in the ferment, potentially able to secret it into the cytoplasm of the infected cell, immunoblotting with obtained antibodies had demonstrated specific accumulation of the protease in the insoluble fraction of spore homogenate. At the same time, the ferment was absent in intracellular stages.of the parasite and also in the cytoplasm of infested host cells. Accumulation of mRNA, coding the studied protein in microsporidian spores was confirmed with the use of RT-PCR method. Heterologous expression of the protease in the methylotrophic yeast Pichiapastoris demonstrated the same result. The ferment of P. locustae was not secreted into a culture medium and was absent in the cytoplasm of yeast cells, accumulating in a dissoluble (membrane) fraction of the homogenate. On the whole, the obtained data testify to the fact that the subtilisin-like protease of P. locustae plays an important role in the physiology of spores rather than participates in host-parasite relations during intra-cellular development.
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Chen D, Wang Y, Zhou X, Wang Y, Xu JR. The Sch9 kinase regulates conidium size, stress responses, and pathogenesis in Fusarium graminearum. PLoS One 2014; 9:e105811. [PMID: 25144230 PMCID: PMC4140829 DOI: 10.1371/journal.pone.0105811] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 07/24/2014] [Indexed: 11/20/2022] Open
Abstract
Fusarium head blight caused by Fusarium graminearum is an important disease of wheat and barley worldwide. In a previous study on functional characterization of the F. graminearum kinome, one protein kinase gene important for virulence is orthologous to SCH9 that is functionally related to the cAMP-PKA and TOR pathways in the budding yeast. In this study, we further characterized the functions of FgSCH9 in F. graminearum and its ortholog in Magnaporthe oryzae. The ΔFgsch9 mutant was slightly reduced in growth rate but significantly reduced in conidiation, DON production, and virulence on wheat heads and corn silks. It had increased tolerance to elevated temperatures but became hypersensitive to oxidative, hyperosmotic, cell wall, and membrane stresses. The ΔFgsch9 deletion also had conidium morphology defects and produced smaller conidia. These results suggest that FgSCH9 is important for stress responses, DON production, conidiogenesis, and pathogenesis in F. graminearum. In the rice blast fungus Magnaporthe oryzae, the ΔMosch9 mutant also was defective in conidiogenesis and pathogenesis. Interestingly, it also produced smaller conidia and appressoria. Taken together, our data indicate that the SCH9 kinase gene may have a conserved role in regulating conidium size and plant infection in phytopathogenic ascomycetes.
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Affiliation(s)
- Daipeng Chen
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Yang Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaoying Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Yulin Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
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Jacob S, Foster AJ, Yemelin A, Thines E. Histidine kinases mediate differentiation, stress response, and pathogenicity in Magnaporthe oryzae. Microbiologyopen 2014; 3:668-87. [PMID: 25103193 PMCID: PMC4234259 DOI: 10.1002/mbo3.197] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 06/11/2014] [Accepted: 06/20/2014] [Indexed: 01/11/2023] Open
Abstract
The aim of this study is a functional characterization of 10 putative histidine kinases (HIKs)-encoding genes in the phytopathogenic fungus Magnaporthe oryzae. Two HIKs were found to be required for pathogenicity in the fungus. It was found that the mutant strains ΔMohik5 and ΔMohik8 show abnormal conidial morphology and furthermore ΔMohik5 is unable to form appressoria. Both HIKs MoHik5p and MoHik8p appear to be essential for pathogenicity since the mutants fail to infect rice plants. MoSln1p and MoHik1p were previously reported to be components of the HOG pathway in M. oryzae. The ΔMosln1 mutant is more susceptible to salt stress compared to ΔMohik1, whereas ΔMohik1 appears to be stronger affected by osmotic or sugar stress. In contrast to yeast, the HOG signaling cascade in phytopathogenic fungi apparently comprises more elements. Furthermore, vegetative growth of the mutants ΔMohik5 and ΔMohik9 was found to be sensitive to hypoxia-inducing NaNO2-treatment. Additionally, it was monitored that NaNO2-treatment resulted in MoHog1p phosphorylation. As a consequence we assume a first simplified model for hypoxia signaling in M. oryzae including the HOG pathway and the HIKs MoHik5p and MoHik9p.
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Affiliation(s)
- Stefan Jacob
- Institute of Biotechnology and Drug Research (IBWF)Erwin-Schrödinger-Str. 56, D-67663, Kaiserslautern, Germany
- Correspondence Stefan Jacob or Eckhard Thines, Institute of Biotechnology and Drug Research (IBWF), Erwin-Schrödinger-Str. 56, D-67663 Kaiserslautern, Germany., Tel: 0631-3167221; 0631-3167220;, Fax: 0631-3167215;, E-mails: ;
| | - Andrew J Foster
- Institute of Biotechnology and Drug Research (IBWF)Erwin-Schrödinger-Str. 56, D-67663, Kaiserslautern, Germany
| | - Alexander Yemelin
- Institute of Biotechnology and Drug Research (IBWF)Erwin-Schrödinger-Str. 56, D-67663, Kaiserslautern, Germany
| | - Eckhard Thines
- Institute of Biotechnology and Drug Research (IBWF)Erwin-Schrödinger-Str. 56, D-67663, Kaiserslautern, Germany
- Johannes Gutenberg-University Mainz, Institute of Biotechnology and Drug ResearchDuesbergweg 10-14, D-55128, Mainz, Germany
- Correspondence Stefan Jacob or Eckhard Thines, Institute of Biotechnology and Drug Research (IBWF), Erwin-Schrödinger-Str. 56, D-67663 Kaiserslautern, Germany., Tel: 0631-3167221; 0631-3167220;, Fax: 0631-3167215;, E-mails: ;
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Shi L, Li Z, Tachikawa H, Gao XD, Nakanishi H. Use of yeast spores for microencapsulation of enzymes. Appl Environ Microbiol 2014; 80:4502-10. [PMID: 24837390 PMCID: PMC4148785 DOI: 10.1128/aem.00153-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 03/31/2014] [Indexed: 11/20/2022] Open
Abstract
Here, we report a novel method to produce microencapsulated enzymes using Saccharomyces cerevisiae spores. In sporulating cells, soluble secreted proteins are transported to the spore wall. Previous work has shown that the spore wall is capable of retaining soluble proteins because its outer layers work as a diffusion barrier. Accordingly, a red fluorescent protein (RFP) fusion of the α-galactosidase, Mel1, expressed in spores was observed in the spore wall even after spores were subjected to a high-salt wash in the presence of detergent. In vegetative cells, however, the cell wall cannot retain the RFP fusion. Although the spore wall prevents diffusion of proteins, it is likely that smaller molecules, such as sugars, pass through it. In fact, spores can contain much higher α-galactosidase activity to digest melibiose than vegetative cells. When present in the spore wall, the enzyme acquires resistance to environmental stresses including enzymatic digestion and high temperatures. The outer layers of the spore wall are required to retain enzymes but also decrease accessibility of the substrates. However, mutants with mild spore wall defects can retain and stabilize the enzyme while still permitting access to the substrate. In addition to Mel1, we also show that spores can retain the invertase. Interestingly the encapsulated invertase has significantly lower activity toward raffinose than toward sucrose.This suggests that substrate selectivity could be altered by the encapsulation.
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Affiliation(s)
- Libing Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zijie Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Hiroyuki Tachikawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Xiao-Dong Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Hideki Nakanishi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Beauvais A, Bozza S, Kniemeyer O, Formosa C, Balloy V, Henry C, Roberson RW, Dague E, Chignard M, Brakhage AA, Romani L, Latgé JP. Deletion of the α-(1,3)-glucan synthase genes induces a restructuring of the conidial cell wall responsible for the avirulence of Aspergillus fumigatus. PLoS Pathog 2013; 9:e1003716. [PMID: 24244155 PMCID: PMC3828178 DOI: 10.1371/journal.ppat.1003716] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 08/22/2013] [Indexed: 01/12/2023] Open
Abstract
α-(1,3)-Glucan is a major component of the cell wall of Aspergillus fumigatus, an opportunistic human fungal pathogen. There are three genes (AGS1, AGS2 and AGS3) controlling the biosynthesis of α-(1,3)-glucan in this fungal species. Deletion of all the three AGS genes resulted in a triple mutant that was devoid of α-(1,3)-glucan in its cell wall; however, its growth and germination was identical to that of the parental strain in vitro. In the experimental murine aspergillosis model, this mutant was less pathogenic than the parental strain. The AGS deletion resulted in an extensive structural modification of the conidial cell wall, especially conidial surface where the rodlet layer was covered by an amorphous glycoprotein matrix. This surface modification was responsible for viability reduction of conidia in vivo, which explains decrease in the virulence of triple agsΔ mutant. Aspergillus fumigatus is the predominant mold pathogen of humans, responsible for life-threatening systemic infections in patients with depressed immunity. Because of its external localization and specific composition, the fungal cell wall represents a target for recognition by and interaction with the host immune cells. In A. fumigatus, α-(1,3)-glucan is a key component of the extracellular matrix, which encloses the cell wall β-(1,3)-glucan-chitin fibrillar core. Interestingly, the deletion of the genes responsible for α-(1,3)-glucan synthesis resulted in a mutant that exhibited wild type phenotype in vitro; while the altered cell wall organization resulted in this fungus being avirulent in vivo. This study confirms that any modification in the cell wall components is associated with compensatory reactions developed by the fungus to counteract stress on the cell wall that may result in unexpected fungal response when challenged with the host immune system.
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Affiliation(s)
- Anne Beauvais
- Unité des Aspergillus, Institut Pasteur, Paris, France
- * E-mail:
| | - Silvia Bozza
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy
| | - Olaf Kniemeyer
- Molecular and Applied Microbiology, Leibniz-Institute for Natural Product Research and Infection Biology (HKI), University of Jena, Jena, Germany
- Integrated Research and Treatment Center, Center for Sepsis Control and Care Jena, University Hospital (CSCC), Jena, Germany
| | | | - Viviane Balloy
- Unité de Défence Innée et Inflammation, Institut Pasteur, Inserm U874, Paris, France
| | | | - Robert W. Roberson
- School of Life Sciences, Arizona State University, Tempe, Arizona, United States of America
| | | | - Michel Chignard
- Unité de Défence Innée et Inflammation, Institut Pasteur, Inserm U874, Paris, France
| | - Axel A. Brakhage
- Molecular and Applied Microbiology, Leibniz-Institute for Natural Product Research and Infection Biology (HKI), University of Jena, Jena, Germany
| | - Luigina Romani
- Department of Experimental Medicine and Biochemical Sciences, University of Perugia, Perugia, Italy
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Zhang C, Zhang S, Diao H, Zhao H, Zhu X, Lu F, Lu Z. Purification and characterization of a temperature- and pH-stable laccase from the spores of Bacillus vallismortis fmb-103 and its application in the degradation of malachite green. J Agric Food Chem 2013; 61:5468-73. [PMID: 23706133 DOI: 10.1021/jf4010498] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Malachite green residue can affect aquaculture food safety. Bioremediation of contaminated water by enzyme treatment is an environmentally friendly and economical way to remove contaminating substances. In the present study, a temperature- and pH-stable laccase was purified from the spores of Bacillus ballismortis fmb-103 and was used to degrade malachite green. The laccase from fmb-103 (fmb-L103) was purified 15.2-fold to homogeneity (389.9 mU/mg protein with respect to ABTS as a substrate) by precipitation with 30-80% (NH4)2SO4, DEAE-Sephadex A-50 ion exchange chromatography, and Sephadex G-100 chromatography. fmb-L103 is a nonblue laccase with a molecular weight of 55.0 kDa and Cu content of 2.5 (mol:mol). fmb-L103 retained more than 50% activity after 10 h at 70 °C and demonstrated broad pH stability in both acidic and alkaline conditions. The effects of inhibitors and metal ions on fmb-L103 activity were also examined. A kinetic study revealed that ABTS was a suitable substrate with a Km of 22.7 μmol and a Vmax of 3.32 μmol/mL/min. fmb-L103 can efficiently degrade malachite green after a 48 h treatment period in combination with a mediator, without the appearance of leucomalachite green.
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Affiliation(s)
- Chong Zhang
- Laboratory of Enzyme Engineering, College of Food Science and Technology, Nanjing Agriculture University, Nanjing 210095, PR China
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23
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Morita Y, Hyon GS, Hosogi N, Miyata N, Nakayashiki H, Muranaka Y, Inada N, Park P, Ikeda K. Appressorium-localized NADPH oxidase B is essential for aggressiveness and pathogenicity in the host-specific, toxin-producing fungus Alternaria alternata Japanese pear pathotype. Mol Plant Pathol 2013; 14:365-378. [PMID: 23279187 PMCID: PMC6638787 DOI: 10.1111/mpp.12013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Black spot disease, Alternaria alternata Japanese pear pathotype, produces the host-specific toxin AK-toxin, an important pathogenicity factor. Previously, we have found that hydrogen peroxide is produced in the hyphal cell wall at the plant-pathogen interaction site, suggesting that the fungal reactive oxygen species (ROS) generation machinery is important for pathogenicity. In this study, we identified two NADPH oxidase (NoxA and NoxB) genes and produced nox disruption mutants. ΔnoxA and ΔnoxB disruption mutants showed increased hyphal branching and spore production per unit area. Surprisingly, only the ΔnoxB disruption mutant compromised disease symptoms. A fluorescent protein reporter assay revealed that only NoxB localized at the appressoria during pear leaf infection. In contrast, both NoxA and NoxB were highly expressed on the cellulose membrane, and these Nox proteins were also localized at the appressoria. In the ΔnoxB disruption mutant, we could not detect any necrotic lesions caused by AK-toxin. Moreover, the ΔnoxB disruption mutant did not induce papilla formation on pear leaves. Ultrastructural analysis revealed that the ΔnoxB disruption mutant also did not penetrate the cuticle layer. Moreover, ROS generation was not essential for penetration, suggesting that NoxB may have an unknown function in penetration. Taken together, our results suggest that NoxB is essential for aggressiveness and basal pathogenicity in A. alternata.
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Affiliation(s)
- Yuichi Morita
- Graduate School of Agricultural Science, Kobe University, Kobe, Japan
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24
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Cosentino-Gomes D, Rocco-Machado N, Santi L, Broetto L, Vainstein MH, Meyer-Fernandes JR, Schrank A, Beys-da-Silva WO. Inhibition of ecto-phosphatase activity in conidia reduces adhesion and virulence of Metarhizium anisopliae on the host insect Dysdercus peruvianus. Curr Microbiol 2013; 66:467-74. [PMID: 23306352 DOI: 10.1007/s00284-012-0296-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 12/03/2012] [Indexed: 01/17/2023]
Abstract
Metarhizium anisopliae is an entomopathogenic fungus with the ability to infect a broad range of arthropods, and have evolved distinct strategies for their attachment to hosts. Here, we describe the characterisation of ecto-phosphatase activity on the conidia surface of M. anisopliae and its relevance in the host interaction process. Ecto-phosphatase activity was linear for 60 min and during this time, was linear with the increase of cell density. The optimum pH was in the acidic range and some divalent metals, such as Cu(2+), Cd(2+) and Zn(2+), inhibited ecto-phosphatase activity. The activity was also reduced by phosphatase inhibitors. Importantly, the inhibition of phosphatase activity in conidia reduced the adhesion to Dysdercus peruvianus (Hemiptera: Pyrrhocoridae) integument and, consequently and indirectly, M. anisopliae infection. The results herein presented show, for the first time, the importance of ecto-phosphatase activity in M. anisopliae conidia and provide the first evidence of its direct involvement in adhesion and host infection.
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Affiliation(s)
- Daniela Cosentino-Gomes
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Bloco H, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ 21941-902, Brazil
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25
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Bowman BJ, Abreu S, Johl JK, Bowman EJ. The pmr gene, encoding a Ca2+-ATPase, is required for calcium and manganese homeostasis and normal development of hyphae and conidia in Neurospora crassa. Eukaryot Cell 2012; 11:1362-70. [PMID: 22983986 PMCID: PMC3486030 DOI: 10.1128/ec.00105-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 09/06/2012] [Indexed: 12/17/2022]
Abstract
The pmr gene is predicted to encode a Ca(2+)-ATPase in the secretory pathway. We examined two strains of Neurospora crassa that lacked PMR: the Δpmr strain, in which pmr was completely deleted, and pmr(RIP), in which the gene was extensively mutated. Both strains had identical, complex phenotypes. Compared to the wild type, these strains required high concentrations of calcium or manganese for optimal growth and had highly branched, slow-growing hyphae. They conidiated poorly, and the shape and size of the conidia were abnormal. Calcium accumulated in the Δpmr strains to only 20% of the wild-type level. High concentrations of MnCl(2) (1 to 5 mM) in growth medium partially suppressed the morphological defects but did not alter the defect in calcium accumulation. The Δpmr Δnca-2 double mutant (nca-2 encodes a Ca(2+)-ATPase in the plasma membrane) accumulated 8-fold more calcium than the wild type, and the morphology of the hyphae was more similar to that of wild-type hyphae. Previous experiments failed to show a function for nca-1, which encodes a SERCA-type Ca(2+)-ATPase in the endoplasmic reticulum (B. J. Bowman, S. Abreu, E. Margolles-Clark, M. Draskovic, and E. J. Bowman, Eukaryot. Cell 10:654-661, 2011). The pmr(RIP) Δnca-1 double mutant accumulated small amounts of calcium, like the Δpmr strain, but exhibited even more extreme morphological defects. Thus, PMR can apparently replace NCA-1 in the endoplasmic reticulum, but NCA-1 cannot replace PMR. The morphological defects in the Δpmr strain are likely caused, in part, by insufficient concentrations of calcium and manganese in the Golgi compartment; however, PMR is also needed to accumulate normal levels of calcium in the whole cell.
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Affiliation(s)
- Barry J Bowman
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA, USA.
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26
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Tsai HC, Yang SL, Chung KR. Cyclic AMP-dependent protein kinase A negatively regulates conidia formation by the tangerine pathotype of Alternaria alternata. World J Microbiol Biotechnol 2012; 29:289-300. [PMID: 23054702 DOI: 10.1007/s11274-012-1182-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 09/24/2012] [Indexed: 01/24/2023]
Abstract
The necrotrophic fungal pathogen Alternaria alternata causes brown spot diseases in many citrus cultivars. The FUS3 and SLT2 mitogen-activated protein kinases (MAPK)-mediated signaling pathways have been shown to be required for conidiation. Exogenous application of cAMP to this fungal pathogen decreased conidia formation considerably. This study determined whether a cAMP-activated protein kinase A (PKA) is required for conidiation. Using loss-of-function mutations in PKA catalytic and regulatory subunit-coding genes, we demonstrated that PKA negatively regulates conidiation. Fungal mutants lacking PKA catalytic subunit gene (PKA ( cat )) reduced growth, lacked detectable PKA activity, and produced higher amounts of conidia compared to wild-type. Introduction of a functional copy of PKA ( cat ) into a null mutant partially restored PKA activity and produced wild-type level of conidia. In contrast, fungi lacking PKA regulatory subunit gene (PKA ( reg )) produced detectable PKA activity, exhibited severe growth reduction, formed swelling hyphal segments, and produced no mature conidia. Introduction of the PKA ( reg ) gene to a regulatory subunit mutant restored all phenotypes to wild type. PKA ( reg )-null mutants induced fewer necrotic lesions on citrus compared to wild-type, whereas PKA ( cat ) mutant displayed wild-type virulence. Overall, our studies indicate that PKA and FUS3-mediated signaling pathways apparently have very different roles in the regulation of conidia production and A. alternata pathogenesis in citrus.
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Affiliation(s)
- Hsieh-Chin Tsai
- Citrus Research and Education Center, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 700 Experiment Station Road, Lake Alfred, FL 33850, USA
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Etxebeste O, Herrero-García E, Cortese MS, Garzia A, Oiartzabal-Arano E, de los Ríos V, Ugalde U, Espeso EA. GmcA is a putative glucose-methanol-choline oxidoreductase required for the induction of asexual development in Aspergillus nidulans. PLoS One 2012; 7:e40292. [PMID: 22792266 PMCID: PMC3390393 DOI: 10.1371/journal.pone.0040292] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 06/05/2012] [Indexed: 11/18/2022] Open
Abstract
Aspergillus nidulans asexual differentiation is induced by Upstream Developmental Activators (UDAs) that include the bZIP-type Transcription Factor (TF) FlbB. A 2D-PAGE/MS-MS-coupled screen for proteins differentially expressed in the presence and absence of FlbB identified 18 candidates. Most candidates belong to GO term classes involved in osmotic and/or oxidative stress response. Among these, we focused on GmcA, a putative glucose-methanol-choline oxidoreductase which is upregulated in a ΔflbB background. GmcA is not required for growth since no differences were detected in the radial extension upon deletion of gmcA. However, its activity is required to induce conidiation under specific culture conditions. A ΔgmcA strain conidiates profusely under acid conditions but displays a characteristic fluffy aconidial phenotype in alkaline medium. The absence of asexual development in a ΔgmcA strain can be suppressed, on one hand, using high concentrations of non-fermentable carbon sources like glycerol, and on the other hand, when the cMyb-type UDA TF flbD is overexpressed. Overall, the results obtained in this work support a role for GmcA at early stages of conidiophore initiation.
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Affiliation(s)
- Oier Etxebeste
- Department of Applied Chemistry, Faculty of Chemistry, University of The Basque Country, Manuel de Lardizabal, San Sebastian, Spain.
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Luo YY, Yang JK, Zhu ML, Liu CJ, Li HY, Lu ZB, Pan WZ, Zhang ZH, Bi W, Zhang KQ. The group III two-component histidine kinase AlHK1 is involved in fungicides resistance, osmosensitivity, spore production and impacts negatively pathogenicity in Alternaria longipes. Curr Microbiol 2012; 64:449-56. [PMID: 22349956 DOI: 10.1007/s00284-012-0093-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2011] [Accepted: 01/29/2012] [Indexed: 10/28/2022]
Abstract
Members of group III histidine kinases from different filamentous fungi were previously shown to mediate osmoregulation and resistance to dicarboximide, phenylpyrrole and, aromatic hydrocarbon fungicides. In this study, we report the disruption of the gene encoding group III histidine kinase, AlHK1, in the economically important plant pathogen Alternaria longipes. The AlHK1 gene disruption had pleiotropic effects on this fungus. Besides the expected osmosensitivity and fungicides resistance, AlHK1 participated in the spore production process. In addition, the ΔAlHK1 strains had stronger aggressive ability to infect their host plant than that of their parental strain, the wild-type strain C-00, suggested that AlHK1 was involved in the pathogenicity of A. longipes and performed in this function by a negative manner. This is the first report to our knowledge.
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Affiliation(s)
- Yi Yong Luo
- Laboratory of Applied Microbiology, Biotechnology Research Center, Kunming University of Science and Technology, Chenggong Higher Education Mega Center, Kunming 650500, People's Republic of China.
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29
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Xie XQ, Li F, Ying SH, Feng MG. Additive contributions of two manganese-cored superoxide dismutases (MnSODs) to antioxidation, UV tolerance and virulence of Beauveria bassiana. PLoS One 2012; 7:e30298. [PMID: 22279579 PMCID: PMC3261187 DOI: 10.1371/journal.pone.0030298] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 12/13/2011] [Indexed: 11/19/2022] Open
Abstract
The biocontrol potential of entomopathogenic fungi against arthropod pests depends on not only their virulence to target pests but tolerance to outdoor high temperature and solar UV irradiation. Two Beauveria bassiana superoxide dismutases (SODs), BbSod2 and BbSod3, were characterized as cytosolic and mitochondrial manganese-cored isoenzymes (MnSODs) dominating the total SOD activity of the fungal entomopathogen under normal growth conditions. To probe their effects on the biocontrol potential of B. bassiana, ΔBbSod2, ΔBbSod3, and three hairpin RNA-interfered (RNAi) mutants with the transcripts of both BbSod2 and BbSod3 being suppressed by 91-97% were constructed and assayed for various phenotypic parameters in conjunction with ΔBbSod2/BbSod2, ΔBbSod3/BbSod3 and wild-type (control strains). In normal cultures, the knockout and RNAi mutants showed significant phenotypic alterations, including delayed sporulation, reduced conidial yields, and impaired conidial quality, but little change in colony morphology. Their mycelia or conidia became much more sensitive to menadione or H(2)O(2)-induced oxidative stress but had little change in sensitivity to the hyperosmolarity of NaCl and the high temperature of 45°C. Accompanied with the decreased antioxidative capability, conidial tolerances to UV-A and UV-B irradiations were reduced by 16.8% and 45.4% for ΔBbSod2, 18.7% and 44.7% for ΔBbSod3, and ∼33.7% and ∼63.8% for the RNAi mutants, respectively. Their median lethal times (LT(50)s) against Myzus persicae apterae, which were topically inoculated under a standardized spray, were delayed by 18.8%, 14.5% and 37.1%, respectively. Remarkably, the effects of cytosolic BbSod2 and mitochondrial BbSod3 on the phenotypic parameters important for the fungal bioncontrol potential were additive, well in accordance with the decreased SOD activities and the increased superoxide levels in the knockout and RNAi mutants. Our findings highlight for the first time that the two MnSODs co-contribute to the biocontrol potential of B. bassiana by mediating cellular antioxidative response.
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Affiliation(s)
- Xue-Qin Xie
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Fang Li
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
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Velasco-Lozano S, Volke-Sepulveda T, Favela-Torres E. Lipases production by solid-state fermentation: the case of Rhizopus homothallicus in perlite. Methods Mol Biol 2012; 861:227-237. [PMID: 22426722 DOI: 10.1007/978-1-61779-600-5_14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Lipases are widely used in the industry for different purposes. Although these enzymes are mainly produced by submerged fermentation, lipase production by solid-state fermentation (SSF) has been gaining interest due to the advantages of this type of culture. Major advantages are higher production titers and productivity, less catabolite repression, and use of the dried fermented material as biocatalyst. This chapter describes a traditional methodology to produce fungal (Rhizopus homothallicus) lipases by SSF using perlite as inert support. The use of different devices (glass columns or Erlenmeyer flasks) and type of inoculum (spores or growing mycelium) is considered so that lipase production by SSF could be easily performed in any laboratory.
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Affiliation(s)
- Susana Velasco-Lozano
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, D.F. Mexico, Mexico
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Wu P, Zhao R, Ye Y, Wu JQ. Roles of the DYRK kinase Pom2 in cytokinesis, mitochondrial morphology, and sporulation in fission yeast. PLoS One 2011; 6:e28000. [PMID: 22174761 PMCID: PMC3236194 DOI: 10.1371/journal.pone.0028000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/29/2011] [Indexed: 01/04/2023] Open
Abstract
Pom2 is predicted to be a dual-specificity tyrosine-phosphorylation regulated kinase (DYRK) related to Pom1 in Schizosaccharomyces pombe. DYRKs share a kinase domain capable of catalyzing autophosphorylation on tyrosine and exogenous phosphorylation on serine/threonine residues. Here we show that Pom2 is functionally different from the well-characterized Pom1, although they share 55% identity in the kinase domain and the Pom2 kinase domain functionally complements that of Pom1. Pom2 localizes to mitochondria throughout the cell cycle and to the contractile ring during late stages of cytokinesis. Overexpression but not deletion of pom2 results in severe defects in cytokinesis, indicating that Pom2 might share an overlapping function with other proteins in regulating cytokinesis. Gain and loss of function analyses reveal that Pom2 is required for maintaining mitochondrial morphology independently of microtubules. Intriguingly, most meiotic pom2Δ cells form aberrant asci with meiotic and/or forespore membrane formation defects. Taken together, Pom2 is a novel DYRK kinase involved in regulating cytokinesis, mitochondrial morphology, meiosis, and sporulation in fission yeast.
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Affiliation(s)
- Pengcheng Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America.
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Islam MT, von Tiedemann A, Laatsch H. Protein kinase C is likely to be involved in zoosporogenesis and maintenance of flagellar motility in the peronosporomycete zoospores. Mol Plant Microbe Interact 2011; 24:938-947. [PMID: 21486142 DOI: 10.1094/mpmi-12-10-0280] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The motility of zoospores is critical in the disease cycles of Peronosporomycetes that cause devastating diseases in plants, fishes, vertebrates, and microbes. In the course of screening for secondary metabolites, we found that ethyl acetate extracts of a marine Streptomyces sp. strain B5136 rapidly impaired the motility of zoospores of the grapevine downy mildew pathogen Plasmopara viticola at 0.1 μg/ml. The active principle in the extracts was identified as staurosporine, a known broad-spectrum inhibitor of protein kinases, including protein kinase C (PKC). In the presence of staurosporine (2 nM), zoospores moved very slowly in their axis or spun in tight circles, instead of displaying straight swimming in a helical fashion. Compounds such as K-252a, K-252b, and K-252c structurally related to staurosporine also impaired the motility of zoospores in a similar manner but at varying doses. Among the 22 known kinase inhibitors tested, the PKC inhibitor chelerythrine was the most potent to arrest the motility of zoospores at concentrations starting from 5 nM. Inhibitors that targeted kinase pathways other than PKC pathways did not practically show any activity in impairing zoospore motility. Interestingly, both staurosporine (5 nM) and chelerythrine (10 nM) also inhibited the release of zoospores from the P. viticola sporangia in a dose-dependent manner. In addition, staurosporine completely suppressed downy mildew disease in grapevine leaves at 2 μM, suggesting the potential of small-molecule PKC inhibitors for the control of peronosporomycete phytopathogens. Taken together, these results suggest that PKC is likely to be a key signaling mediator associated with zoosporogenesis and the maintenance of flagellar motility in peronosporomycete zoospores.
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Affiliation(s)
- Md Tofazzal Islam
- Department of Crop Science, Georg-August-Universität Göttingen, Germany.
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Vinetskiĭ IP, Rozhkova AM, Sereda AS, Tsurikova NV, Nurtaeva AK, Semenova MV, Zorov IN, Sinitsyn AP. [Increase in glucoamylase productivity of Aspergillus awamori strain by combination of radiating mutagenesis and plasmid transformation methods]. Prikl Biokhim Mikrobiol 2010; 46:685-692. [PMID: 21261079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Increase in the level of amylolytic genes activator protein encoded by amyR gene was shown to result in enhancement of glucoamylase productivity of A. awamori strain by 30%. However, the same effect equal to 30% increase can be achieved by introduction of extra copies of gla gene encoding glucoamylase. These two effects were not additive, which gave the possibility to suggest an additional limitation in the egulation mechanism of glucoamylase gene expression in Aspergillus family strains while introducing an additional copies of amyR and gla genes.
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Ramanujam R, Naqvi NI. PdeH, a high-affinity cAMP phosphodiesterase, is a key regulator of asexual and pathogenic differentiation in Magnaporthe oryzae. PLoS Pathog 2010; 6:e1000897. [PMID: 20463817 PMCID: PMC2865543 DOI: 10.1371/journal.ppat.1000897] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2009] [Accepted: 04/05/2010] [Indexed: 02/07/2023] Open
Abstract
Cyclic AMP-dependent pathways mediate the communication between external stimuli and the intracellular signaling machinery, thereby influencing important aspects of cellular growth, morphogenesis and differentiation. Crucial to proper function and robustness of these signaling cascades is the strict regulation and maintenance of intracellular levels of cAMP through a fine balance between biosynthesis (by adenylate cyclases) and hydrolysis (by cAMP phosphodiesterases). We functionally characterized gene-deletion mutants of a high-affinity (PdeH) and a low-affinity (PdeL) cAMP phosphodiesterase in order to gain insights into the spatial and temporal regulation of cAMP signaling in the rice-blast fungus Magnaporthe oryzae. In contrast to the expendable PdeL function, the PdeH activity was found to be a key regulator of asexual and pathogenic development in M. oryzae. Loss of PdeH led to increased accumulation of intracellular cAMP during vegetative and infectious growth. Furthermore, the pdeHDelta showed enhanced conidiation (2-3 fold), precocious appressorial development, loss of surface dependency during pathogenesis, and highly reduced in planta growth and host colonization. A pdeHDelta pdeLDelta mutant showed reduced conidiation, exhibited dramatically increased (approximately 10 fold) cAMP levels relative to the wild type, and was completely defective in virulence. Exogenous addition of 8-Br-cAMP to the wild type simulated the pdeHDelta defects in conidiation as well as in planta growth and development. While a fully functional GFP-PdeH was cytosolic but associated dynamically with the plasma membrane and vesicular compartments, the GFP-PdeL localized predominantly to the nucleus. Based on data from cAMP measurements and Real-Time RTPCR, we uncover a PdeH-dependent biphasic regulation of cAMP levels during early and late stages of appressorial development in M. oryzae. We propose that PdeH-mediated sustenance and dynamic regulation of cAMP signaling during M. oryzae development is crucial for successful establishment and spread of the blast disease in rice.
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Affiliation(s)
- Ravikrishna Ramanujam
- Fungal Patho-Biology Group, Temasek Life Sciences Laboratory, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Naweed I. Naqvi
- Fungal Patho-Biology Group, Temasek Life Sciences Laboratory, Singapore
- School of Biological Sciences, Nanyang Technological University, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore
- * E-mail:
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Pei-Bao Z, Ren AZ, Xu HJ, Li DC. The gene fpk1, encoding a cAMP-dependent protein kinase catalytic subunit homolog, is required for hyphal growth, spore germination, and plant infection in Fusarium verticillioides. J Microbiol Biotechnol 2010; 20:208-216. [PMID: 20134254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Fusarium verticillioides is an important pathogen of maize responsible for ear rots, stalk rots and seeding blight worldwide. During the past decade F. verticillioides has caused several severe epidemics of maize seeding blight in many areas of china, which lead to significant losses. In order to understand molecular mechanisms regulating fungal development and pathogenicity in the pathogen, we isolated and characterized the gene fpk1 (GenBank accession NO. EF405959) encoding catalytic subunit of cAMP-dependent protein kinase, which include 1854 bp DNA sequence from ATG to TAA, with 1680 bp coding region, three intron (their length: 66bp, 54bp and 54bp), and the predicated protein had 559 aa. The mutantdeltafpk1, which was disrupted of fpk1 gene, showed reduced vegetative growth, fewer and shorter aerial mycelia, strongly impaired conidiation and reduced spore germination rate. After germinating, the fresh hypha was stubby and lack of branch. When inoculated in susceptible maize varieties, the infection of the mutantdeltafpk1 was delayed and the infection efficiency was reduced than that of the wild-type. All this indicated that the gene fpk1 participated in hyphal growth, conidiophore producing, spore germination and virulence in F. verticillioides.
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Affiliation(s)
- Zhao Pei-Bao
- College of Plant Protection, Shandong Agricultural University, Taian, Shandong, 271018, China
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Lev S, Tal H, Rose MS, Horwitz BA. Signaling by the pathogenicity-related MAP kinase of Cochliobolus heterostrophus correlates with its local accumulation rather than phosphorylation. Mol Plant Microbe Interact 2009; 22:1093-1103. [PMID: 19656044 DOI: 10.1094/mpmi-22-9-1093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phosphorylated mitogen-activated protein kinases (MAPK) transmit signals by activation of their targets. The extent of signal transduction could depend on MAPK phosphorylation level, concentration, and subcellular localization. The pathogenicity MAPK Chk1 of the fungal corn pathogen Cochliobolus heterostrophus is required for central developmental functions, including appressoria formation, conidiation, melanization, virulence, and female fertility. We followed CHK1 transcript level, protein localization, quantity, phosphorylation, and expression of downstream genes during conidial germination on a surface inductive for appressoria formation and in suspension. The Chk1-GFP protein representing a translational fusion of Chk1 and GFP (green fluorescent protein) was very abundant in ungerminated conidia, accumulated in maturating appressoria and appressorial nuclei, but was uniformly distributed in suspension-grown hyphae. Expression of Chk1-dependent genes was upregulated in appressoria-forming hyphae but not in suspension. Despite Chk1 activation, there was no change in its phosphorylation and total protein quantity. Of all conditions tested, a temperature shift caused a decrease whereas hyperosmotic stress caused an increase in Chk1 phosphorylation. Activation of Chk1 during appressoria formation is apparently manifested by its local accumulation but not by significant changes in phosphorylation.
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Affiliation(s)
- Sophie Lev
- Department of Biology, Technion-Israel Institute of Technology, Haifa Israel
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Rho HS, Jeon J, Lee YH. Phospholipase C-mediated calcium signalling is required for fungal development and pathogenicity in Magnaporthe oryzae. Mol Plant Pathol 2009; 10:337-46. [PMID: 19400837 PMCID: PMC6640429 DOI: 10.1111/j.1364-3703.2009.00536.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Calcium signalling has profound implications in the fungal infection of plants and animals, during which a series of physiological and morphological transitions are required. In this article, using a model fungal pathogen, Magnaporthe oryzae, we demonstrate that the regulation of the intracellular calcium concentration ([Ca(2+)](int)) is essential for fungal development and pathogenesis. Imaging of [Ca(2+)](int) showed that infection-specific morphogenesis is highly correlated with the spatiotemporal regulation of calcium flux. Deletion of the fungal phospholipase C gene (M. oryzae phospholipase C 1, MoPLC1) suppressed calcium flux, resulting in a fungus defective in developmental steps, including appressorium formation and pathogenicity. Surprisingly, the PLC-delta1 gene of mouse was able to functionally substitute for MoPLC1 by restoring the calcium flux, suggesting the evolutionary conservation of the phospholipase C-mediated regulation of calcium flux. Our results reveal that MoPLC1 is a conserved modulator of calcium flux that is essential for the regulation of key steps in fungal development and pathogenesis.
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Affiliation(s)
- Hee-Sool Rho
- Department of Agricultural Biotechnology, Center for Fungal Pathogenesis, and Center for Fungal Genetic Resources, Seoul National University, Seoul, Korea
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Gao X, Brodhagen M, Isakeit T, Brown SH, Göbel C, Betran J, Feussner I, Keller NP, Kolomiets MV. Inactivation of the lipoxygenase ZmLOX3 increases susceptibility of maize to Aspergillus spp. Mol Plant Microbe Interact 2009; 22:222-31. [PMID: 19132874 PMCID: PMC4545248 DOI: 10.1094/mpmi-22-2-0222] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Plant and fungal lipoxygenases (LOX) catalyze the oxidation of polyunsaturated fatty acids, creating fatty-acid hydroperoxides (oxylipins). Fungal oxylipins are required for normal fungal development and secondary metabolism, and plant host-derived oxylipins interfere with these processes in fungi, presumably by signal mimicry. The maize LOX gene ZmLOX3 has been implicated previously in seed-Aspergillus interactions, so we tested the interactions of a mutant maize line (lox3-4, in which ZmLOX3 is disrupted) with the mycotoxigenic seed-infecting fungi Aspergillus flavus and Aspergillus nidulans. The lox3-4 mutant was more susceptible than wild-type maize to both Aspergillus species. All strains of A. flavus and A. nidulans produced more conidia and aflatoxin (or the precursor sterigmatocystin) on lox3-4 kernels than on wild-type kernels, in vitro and under field conditions. Although oxylipins did not differ detectably between A. flavus-infected kernels of the lox3-4 and wild-type (WT) maize, oxylipin precursors (free fatty acids) and a downstream metabolite (jasmonic acid) accumulated to greater levels in lox3-4 than in WT kernels. The increased resistance of the lox3-4 mutant to other fungal pathogens (Fusarium, Colletotrichum, Cochliobolus, and Exserohilum spp.) is in sharp contrast to results described herein for Aspergillus spp., suggesting that outcomes of LOX-governed host-pathogen interactions are pathogen-specific.
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Affiliation(s)
- Xiquan Gao
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77843-2132, USA
| | - Marion Brodhagen
- Departments of Plant Pathology and Medical Microbiology and Immunology, University of Wisconsin - Madison, 1550 Linden Dr., Madison, WI 53706-1598
| | - Tom Isakeit
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77843-2132, USA
| | - Sigal Horowitz Brown
- Departments of Plant Pathology and Medical Microbiology and Immunology, University of Wisconsin - Madison, 1550 Linden Dr., Madison, WI 53706-1598
| | - Cornelia Göbel
- Department of Plant Biochemistry, Georg-August-University, Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| | - Javier Betran
- Department of Soil and Crop Sciences, Corn Breeding and Genetics, Texas A&M University, College Station, TX 77843-2474
| | - Ivo Feussner
- Department of Plant Biochemistry, Georg-August-University, Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| | - Nancy P. Keller
- Departments of Plant Pathology and Medical Microbiology and Immunology, University of Wisconsin - Madison, 1550 Linden Dr., Madison, WI 53706-1598
| | - Michael V. Kolomiets
- Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX, 77843-2132, USA
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Tan KC, Heazlewood JL, Millar AH, Thomson G, Oliver RP, Solomon PS. A signaling-regulated, short-chain dehydrogenase of Stagonospora nodorum regulates asexual development. Eukaryot Cell 2008; 7:1916-29. [PMID: 18776038 PMCID: PMC2583533 DOI: 10.1128/ec.00237-08] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 08/22/2008] [Indexed: 11/20/2022]
Abstract
The fungus Stagonospora nodorum is a causal agent of leaf and glume blotch disease of wheat. It has been previously shown that inactivation of heterotrimeric G protein signaling in Stagonospora nodorum caused development defects and reduced pathogenicity [P. S. Solomon et al., Mol. Plant-Microbe Interact. 17:456-466, 2004]. In this study, we sought to identify targets of the signaling pathway that may have contributed to phenotypic defects of the signaling mutants. A comparative analysis of Stagonospora nodorum wild-type and Galpha-defective mutant (gna1) intracellular proteomes was performed via two-dimensional polyacrylamide gel electrophoresis. Several proteins showed significantly altered abundances when comparing the two strains. One such protein, the short-chain dehydrogenase Sch1, was 18-fold less abundant in the gna1 strain, implying that it is positively regulated by Galpha signaling. Gene expression and transcriptional enhanced green fluorescent protein fusion analyses of Sch1 indicates strong expression during asexual development. Mutant strains of Stagonospora nodorum lacking Sch1 demonstrated poor growth on minimal media and exhibited a significant reduction in asexual sporulation on all growth media examined. Detailed histological experiments on sch1 pycnidia revealed that the gene is required for the differentiation of the subparietal layers of asexual pycnidia resulting in a significant reduction in both pycnidiospore size and numbers.
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Affiliation(s)
- Kar-Chun Tan
- Australian Centre for Necrotrophic Fungal Pathogens, Murdoch University, South Street, Murdoch 6150, Australia
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40
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Iida Y, Kurata T, Harimoto Y, Tsuge T. Nitrite reductase gene upregulated during conidiation is involved in macroconidium formation in Fusarium oxysporum. Phytopathology 2008; 98:1099-1106. [PMID: 18943456 DOI: 10.1094/phyto-98-10-1099] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Fusarium oxysporum produces three kinds of asexual spores, microconidia, macroconidia, and chlamydospores. We previously found that the transcript level of the nitrite reductase gene of F. oxysporum, named FoNIIA, was markedly upregulated during conidiation compared with during vegetative growth. FoNIIA was also found to be positively regulated by Ren1 that is a transcription regulator controlling development of microconidia and macroconidia. In this study, we analyzed the function of FoNIIA in conidiation of F. oxysporum. Conidiation cultures showed markedly higher level of accumulation of FoNiiA protein as well as FoNIIA mRNA than vegetative growth cultures. FoNIIA protein was significantly decreased in cultures of the REN1 disruption mutant compared with that of the wild type. These results confirmed that FoNIIA expression is upregulated during conidiation and is positively regulated by REN1. The FoNIIA disruption mutants produced microconidia, macroconidia, and chlamydospores, which were morphologically indistinguishable from those of the wild type. The mutants, however, produced significantly fewer macroconidia than the wild type, although the wild type and mutant strains produced similar numbers of microconidia and chlamydospores. These results demonstrate that nitrite reductase is involved in quantitative control of macroconidium formation as well as nitrate utilization in F. oxysporum.
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Affiliation(s)
- Y Iida
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Kammoun R, Naili B, Bejar S. Application of a statistical design to the optimization of parameters and culture medium for alpha-amylase production by Aspergillus oryzae CBS 819.72 grown on gruel (wheat grinding by-product). Bioresour Technol 2008; 99:5602-5609. [PMID: 18180155 DOI: 10.1016/j.biortech.2007.10.045] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2006] [Revised: 10/22/2007] [Accepted: 10/24/2007] [Indexed: 05/25/2023]
Abstract
The production optimization of alpha-amylase (E.C.3.2.1.1) from Aspergillus oryzae CBS 819.72 fungus, using a by-product of wheat grinding (gruel) as sole carbon source, was performed with statistical methodology based on three experimental designs. The optimisation of temperature, agitation and inoculum size was attempted using a Box-Behnken design under the response surface methodology. The screening of nineteen nutrients for their influence on alpha-amylase production was achieved using a Plackett-Burman design. KH(2)PO(4), urea, glycerol, (NH(4))(2)SO(4), CoCl(2), casein hydrolysate, soybean meal hydrolysate, MgSO(4) were selected based on their positive influence on enzyme formation. The optimized nutrients concentration was obtained using a Taguchi experimental design and the analysis of the data predicts a theoretical increase in the alpha-amylase expression of 73.2% (from 40.1 to 151.1 U/ml). These conditions were validated experimentally and revealed an enhanced alpha-amylase yield of 72.7%.
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Affiliation(s)
- Radhouane Kammoun
- Centre de Biotechnologie de Sfax, Laboratoire d'Enzymes et Métabolites des Procaryotes, Route de sidi Mansour km 4, BP"K" 3038 Sfax, Tunisia.
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Yike I, Rand T, Dearborn DG. The role of fungal proteinases in pathophysiology of Stachybotrys chartarum. Mycopathologia 2007; 164:171-81. [PMID: 17610048 DOI: 10.1007/s11046-007-9037-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2007] [Accepted: 06/06/2007] [Indexed: 11/25/2022]
Abstract
The adverse health effects of Stachybotrys chartarum have often been linked to exposure to the trichothecene mycotoxins. Recent studies have shown that in addition to mycotoxins this fungus is capable of producing and secreting in vivo proteins such as hemolysins and proteinases. Spore extracts obtained from a high trichothecene producing isolate JS 58-17 exhibited a significantly lower proteolytic activity compared to the low trichothecene producer, JS 58-06. Growing isolates on rice or potato dextrose agar results in higher proteolytic activity of the spores compared to those grown on drywall. Proteinases in the spore extracts can hydrolyze gelatin and collagen I and IV. Analysis of zymograms shows the presence of several proteins with proteolytic activity in the spores of S. chartarum. Human tracheal epithelial cells exposed to spore extracts produced significantly higher levels of IL-6, IL-8, and TNF-alpha than control cells. This stimulation of cytokine production was completely abolished by Pefabloc, a serine protease inhibitor. Neutrophil numbers and proinflammatory cytokine (IL1-beta and TNF-alpha) concentrations were highly elevated in the lungs of 7 day old rat pups exposed intratracheally to 4 x 10(4) spores/gm body weight compared to control. No significant differences in those inflammatory indices in vivo were noted between the treatments with the high trichothecene producer, isolate JS 58-17 and JS 58-06, which does not produce macrocyclic trichothecenes. Immunohistochemistry revealed reduced collagen IV labeling in spore-induced lung granulomas in rat pups exposed to both isolates. These results suggest that proteinases from S. chartarum spores significantly contribute to lung inflammation and injury.
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Affiliation(s)
- Iwona Yike
- Mary Ann Swetland Center for Environmental Health, Case Western Reserve University, Cleveland, OH 44106, USA.
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Ye Y, Fujii M, Hirata A, Kawamukai M, Shimoda C, Nakamura T. Geranylgeranyl diphosphate synthase in fission yeast is a heteromer of farnesyl diphosphate synthase (FPS), Fps1, and an FPS-like protein, Spo9, essential for sporulation. Mol Biol Cell 2007; 18:3568-81. [PMID: 17596513 PMCID: PMC1951748 DOI: 10.1091/mbc.e07-02-0112] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Both farnesyl diphosphate synthase (FPS) and geranylgeranyl diphosphate synthase (GGPS) are key enzymes in the synthesis of various isoprenoid-containing compounds and proteins. Here, we describe two novel Schizosaccharomyces pombe genes, fps1(+) and spo9(+), whose products are similar to FPS in primary structure, but whose functions differ from one another. Fps1 is essential for vegetative growth, whereas, a spo9 null mutant exhibits temperature-sensitive growth. Expression of fps1(+), but not spo9(+), suppresses the lethality of a Saccharomyces cerevisiae FPS-deficient mutant and also restores ubiquinone synthesis in an Escherichia coli ispA mutant, which lacks FPS activity, indicating that S. pombe Fps1 in fact functions as an FPS. In contrast to a typical FPS gene, no apparent GGPS homologues have been found in the S. pombe genome. Interestingly, although neither fps1(+) nor spo9(+) expression alone in E. coli confers clear GGPS activity, coexpression of both genes induces such activity. Moreover, the GGPS activity is significantly reduced in the spo9 mutant. In addition, the spo9 mutation perturbs the membrane association of a geranylgeranylated protein, but not that of a farnesylated protein. Yeast two-hybrid and coimmunoprecipitation analyses indicate that Fps1 and Spo9 physically interact. Thus, neither Fps1 nor Spo9 alone functions as a GGPS, but the two proteins together form a complex with GGPS activity. Because spo9 was originally identified as a sporulation-deficient mutant, we show here that expansion of the forespore membrane is severely inhibited in spo9Delta cells. Electron microscopy revealed significant accumulation membrane vesicles in spo9Delta cells. We suggest that lack of GGPS activity in a spo9 mutant results in impaired protein prenylation in certain proteins responsible for secretory function, thereby inhibiting forespore membrane formation.
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Affiliation(s)
- Yanfang Ye
- *Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Makoto Fujii
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan
| | - Aiko Hirata
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba 277-8562, Japan; and
| | - Makoto Kawamukai
- Department of Applied Bioscience and Biotechnology, Faculty of Life and Environmental Science, Shimane University, Matsue 690-8504, Japan
| | - Chikashi Shimoda
- *Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
| | - Taro Nakamura
- *Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585, Japan
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Vicente-Soler J, Soto T, Madrid M, Núñez A, Cansado J, Gacto M. Solubilization and characterization of a cell wall-bound trehalase from ascospores of the fission yeast Schizosaccharomyces pombe. Microbiol Res 2007; 164:304-11. [PMID: 17428646 DOI: 10.1016/j.micres.2006.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 10/03/2006] [Accepted: 12/08/2006] [Indexed: 10/23/2022]
Abstract
The genome of the fission yeast Schizosaccharomyces pombe lacks sequence homologs to ath1 genes coding for acid trehalases in other yeasts or filamentous fungi. However, acid trehalase activity is present at the spore stage in the life cycle of the fission yeast. The enzyme responsible for this activity behaves as a surface enzyme covalently linked to the spore cell walls in both wild-type and ntp1 mutant strains devoid of neutral trehalase. Lytic treatment of particulated cell wall fractions allowed the solubilization of the enzyme into an active form. We have characterized this soluble enzyme and found that its kinetic parameters, optimum pH and temperature, thermal denaturation and salt responses are closely similar to other conventional acid trehalases. Hence, this rather unusual enzyme can be recognized as acid trehalase by its biochemical properties although it does not share genetic homology with other known acid trehalases. The potential role of such acid trehalase in the mobilization of trehalose is discussed.
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Affiliation(s)
- J Vicente-Soler
- Department of Genetics and Microbiology, Facultad de Biología, University of Murcia, Murcia, Spain
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45
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Spasova D, Aleksieva P, Nacheva L, Radoevska S. Ultracytochemical localization of acid phosphatase in Humicola lutea conidia and mycelia. Z NATURFORSCH C 2007; 62:65-9. [PMID: 17425108 DOI: 10.1515/znc-2007-1-212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Electron microscopic cytochemical procedures were used to determine the cellular location of acid phosphatase in the fungus Humicola lutea grown in casein-containing medium lacking in mineral orthophosphates. In our investigations acid phosphatase in nongerminating conidia was localized on the outer side of the cell wall, in the cell wall, and on the exterior surface of the plasma membrane. The reaction product of acid phosphatase in germinating conidia was seen in the outer wall layer while in young mycelium on the cell surface and in the exocellular space. The relationship between phosphatase activities localized in the cell wall and their role in the enzymatic degradation of the phosphoprotein casein providing available phosphates for cell growth is discussed.
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Affiliation(s)
- Dimitrina Spasova
- Bulgarian Academy of Sciences, Institute of Microbiology, Acad. Georgy Bonchev Str., bl. 26, 1113 Sofia, Bulgaria
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Hoque E, Pflugmacher S, Fritscher J, Wolf M. Induction of glutathione S-transferase in biofilms and germinating spores of Mucor hiemalis strain EH5 from cold sulfidic spring waters. Appl Environ Microbiol 2007; 73:2697-707. [PMID: 17293503 PMCID: PMC1855610 DOI: 10.1128/aem.02786-06] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 01/30/2007] [Indexed: 11/20/2022] Open
Abstract
The occurrence and activation of glutathione S-transferase (GST) and the GST activities in biofilms in cold sulfidic spring waters were compared to the occurrence and activation of GST and the GST activities of the aquatic fungal strains EH5 and EH7 of Mucor hiemalis isolated for the first time from such waters. Using fluorescently labeled polyclonal anti-GST antibodies and GST activity measurements, we demonstrated that a high level of GST occurred in situ in natural biofilms and pure cultures of strain EH5. Measurement of microsomal and cytosolic soluble GST activities using different xenobiotic substrates, including 1-chloro-2,4-dinitrobenzene (CDNB), 1,2-dichloro-4-nitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy)propane, 1-iodo-2,4-dinitrobenzene, and fluorodifen, showed that the overall biotransforming abilities of biofilms were at least sixfold greater than that of strain EH5 alone. Increasing the level of sodium thiosulfate (STS) in the medium stimulated the microsomal and cytosolic GST activities with CDNB of strain EH5 about 44- and 94-fold, respectively, compared to the activities in the control. The induction of microsomal GST activity with fluorodifen by STS was strongly linear, but the initial strong linear increase in cytosolic GST activity with fluorodifen showed saturation-like effects at STS concentrations higher than approximately 1 mM. Using laser scanning confocal and conventional fluorescence microscopy, abundant fluorescently labeled GST proteins were identified in germinating sporangiospores of strain EH5 after activation by STS. High-performance size exclusion chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed the presence of at least two main GSTs ( approximately 27.8- and approximately 25.6-kDa subunits) in the cytosol of EH5, whereas the major 27.8-kDa subunit was the only GST in microsomes. We suggest that differential cellular GST expression takes place in strain EH5 depending on spore and hyphal development. Our results may contribute to our understanding of induction of GST by sulfurous compounds, as well as to the immunofluorescence visualization of GST in aquatic fungus and fungus-bacterium biofilms.
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Affiliation(s)
- Enamul Hoque
- GSF-National Research Center for Environment and Health, Institute of Groundwater Ecology, Ingolstädter Landstr 1, Neuherberg, Germany.
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Ustok FI, Tari C, Gogus N. Solid-state production of polygalacturonase by Aspergillus sojae ATCC 20235. J Biotechnol 2007; 127:322-34. [PMID: 16945442 DOI: 10.1016/j.jbiotec.2006.07.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Revised: 06/16/2006] [Accepted: 07/07/2006] [Indexed: 11/16/2022]
Abstract
The effect of solid substrates, inoculum and incubation time were studied using response surface methodology (RSM) for the production of polygalacturonase enzyme and spores in solid-state fermentation using Aspergillus sojae ATCC 20235. Two-stage optimization procedure was applied using D-optimal and face-centered central composite design (CCD). Crushed maize was chosen as the solid substrate, for maximum polygalacturonase enzyme activity based on D-optimal design. Inoculum and incubation time were determined to have significant effect on enzyme activity and total spore (p<0.01) based on the results of CCD. A second order polynomial regression model was fitted and was found adequate for individual responses. All two models provided an adequate R(2) of 0.9963 (polygalacturonase) and 0.9806 (spores) (p<0.001). The individual optimum values of inoculum and incubation time for maximum production of the two responses were 2 x 10(7) total spores and 5-6 days. The predicted enzyme activity (30.55 U/g solid) and spore count (2.23 x 10(7)spore/ml) were very close to the actual values obtained experimentally (29.093 U/g solid and 2.31 x 10(7)spore/ml, respectively). The overall optimum region considering the two responses together, overlayed with the individual optima. Solid-state fermentation provided 48% more polygalacturonase activity compared to submerged fermentation under individually optimized conditions.
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Affiliation(s)
- Fatma Isik Ustok
- Biotechnology and Bioengineering Programme, Izmir Institute of Technology, Urla, Izmir 35430, Turkey
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48
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Qazi SS, Khachatourians GG. Hydrated conidia of Metarhizium anisopliae release a family of metalloproteases. J Invertebr Pathol 2006; 95:48-59. [PMID: 17292390 DOI: 10.1016/j.jip.2006.12.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2006] [Revised: 12/11/2006] [Accepted: 12/21/2006] [Indexed: 11/15/2022]
Abstract
Metarhizium anisopliae spores release isoforms of metalloprotease during hydration over a 4-day incubation period. The isoforms were identified and characterized by using one-dimensional native PAGE (1-DE nPAGE) and one-dimensional SDS non-dissociating (1-DE nSDS-PAGE) zymography. The ability of these isozymes to degrade gelatin varied as revealed by 2-D spot densitometry. 1-DE nPAGE zymography revealed five isoforms of gelatinase from Tween wash of conidia. Where as, one to three activities with different intensities appeared on gel from washing of conidia to incubation in water till day 4. The relative migrations of these activities on 1-DE nPAGE zymograms appeared as fast, medium and slow on gel. The 2-D spot densitometry of zymograms indicated isoforms have different proteolytic activity as quantified by pixel intensities. SDS-PAGE zymography indicated the release of two isozymes of Mr 103 and 12 kDa during Tween treatment of conidia. However, during the first washing step with water and incubation of spores at day 2 and 3, respectively, only 12 kDa protein was evident. Majority of these proteases were inhibited by EDTA, but stimulated by CaCl(2), and MgCl(2). The presence of isozymes in conidia and their release during hydration must have functional significance for fungi and in this case it should provide advantages to M. anisopliae in its saprobic or pathogenic modalities. To our knowledge this is the first report describing release of metalloprotease isozymes from conidia.
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Affiliation(s)
- Sohail S Qazi
- Microbial Biotechnology/Molecular Microbiology Laboratories, Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Canada.
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Wang N, Yoshida Y, Hasunuma K. Loss of Catalase-1 (Cat-1) results in decreased conidial viability enhanced by exposure to light in Neurospora crassa. Mol Genet Genomics 2006; 277:13-22. [PMID: 17077971 DOI: 10.1007/s00438-006-0170-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Accepted: 09/14/2006] [Indexed: 12/01/2022]
Abstract
Light is one of the most important factors inducing morphogenesis in Neurospora crassa. The reception of light triggers the generation of reactive oxygen species (ROS) including hydrogen peroxide (H(2)O(2)). Catalase-1 (Cat-1) is one of three catalases known to detoxify H(2)O(2) into water and oxygen. We reported that the photomorphogenetic characteristics of mutants in nucleoside diphosphate kinase-1 (NDK-1), a light signal transducer, are severely affected, and NDK-1 interacted with Cat-1 in a yeast two-hybrid assay. To disclose the function of Cat-1, we created a Cat-1 loss-of-function mutant (cat-1 ( RIP )) by the repeat induced point-mutation (RIPing) method. No Cat-1 activity was detected in the mutant strain. Forty guanines were replaced with adenines in the cat-1 gene of cat-1 ( RIP ), which caused 30 amino acid substitutions. The mutant strain grew normally, but its conidia and mycelia were more sensitive to H(2)O(2) than those of the wild type. The lack of Cat-1 activity also caused a significant reduction in the conidial germination rate. Furthermore, light enhanced this reduction in cat-1 ( RIP ) more than that in the wild type. Introduction of cat-1 into the mutant reversed all of these defective phenotypes. These results indicate that Cat-1 plays an important role in supporting the survival of conidia under oxidative and light-induced stress.
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Affiliation(s)
- Niyan Wang
- Kihara Institute for Biological Research, Yokohama City University, 641-12 Maioka-cho, Totsuka-ku, Yokohama, 244-0813, Japan
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Upadhyay S, Shaw BD. A phosphoglucose isomerase mutant in Aspergillus nidulans is defective in hyphal polarity and conidiation. Fungal Genet Biol 2006; 43:739-51. [PMID: 16798030 DOI: 10.1016/j.fgb.2006.05.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 05/09/2006] [Accepted: 05/15/2006] [Indexed: 10/24/2022]
Abstract
Upon germination Aspergillus nidulans swoM1 exhibits abnormal development by extending a primary germ tube that quickly reverts to isotropic growth and results in an enlarged, swollen apex with pronounced wall thickenings. Apical lysis occurs in 38% of the germlings. A point mutation in the AN6037.3 gene encoding the only phosphoglucose isomerase in A. nidulans is responsible for the defect. Loss of polarity is bypassed when glucose is replaced with alternate carbon sources but in all cases the mutant is unable to conidiate due to a block in conidiophore development at vesicle formation. In conidiophores SwoM::GFP localizes to multiple punctate, foci within each actively growing cell type, and to multiple foci in mature dormant conidia. In hyphae SwoM::GFP localized to two rings spanning the center of mature septa. In hyphae localization is concentrated at actively growing hyphal tips.
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Affiliation(s)
- Srijana Upadhyay
- Program for Biology of Filamentous Fungi, Department of Plant Pathology and Microbiology, Texas A&M University, 2132 TAMU, College Station, TX 77843, USA
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