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Wang BB, Wang FH, Wang YJ, Jia YB, Tian SY, Zhang XC, Xue YJ, Li YL, Cai KZ. Microstructure characterization of different types of chlamydospores in Arthrobotrys flagrans. J Basic Microbiol 2024; 64:32-41. [PMID: 37699751 DOI: 10.1002/jobm.202300308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/18/2023] [Accepted: 07/23/2023] [Indexed: 09/14/2023]
Abstract
The morphological and structural differences of different types of chlamydospore of Arthrobotrys flagrans, a nematophagous fungus, were studied under light microscope and electron microscope to provide a reference for the biological control of parasitic nematodiasis. In this study, A. flagrans isolate F088 dormant chlamydospore and nondormant chlamydospore were selected as the research objects. The structural differences of these spores were observed by optical microscopy through lactol cotton blue, Trypan blue, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) staining. FunXite -1, 4',6-diamidino-2-phenylindole, and calcofluor white staining were used to observe the metabolic activity, cell wall, and nucleus differences of the two types of spores under fluorescence microscope. Ultrastructure of the two kinds of spores was observed using scanning electron microscope (SEM) and transmission electron microscope (TEM). Since lacto phenol cotton blue, trypan blue staining cannot distinguish dormant spores from dead spores, MTT assay was performed. Fluorescence microscopy observation showed that the cytoplasmic metabolic activity of nondormant spores was stronger than that of dormant spores. The nucleus of dormant spores was bright blue, and their fluorescence was stronger than that of nondormant spores. The cell wall of nondormant spores produced stronger yellow-green fluorescence than that of dormant spores. Ultrastructural observation showed that there were globular protuberances on the surface of the two types of spores but with no significant difference between them. The inner wall of dormant spore possesses a thick zona pellucida with high electron density which was significantly thicker than that of nondormant spores, and their cytoplasm is also changed. In this study, the microstructure characteristics of dormant and nondormant chlamydospores of A. flagrans fungi were preliminarily clarified, suggesting that the state of cell wall and intracellular materials were changed after spores entered to dormancy.
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Affiliation(s)
- Bo-Bo Wang
- Medical College of Yan'an University, Yan'an, China
- Yan'an Key Laboratory of Zoonotic Parasitology Laboratory, Yan'an, China
| | - Feng-Hui Wang
- Medical College of Yan'an University, Yan'an, China
- Yan'an Key Laboratory of Fungi Resources Development and Biological Control, Yan'an, China
| | - Yu-Jue Wang
- Medical College of Yan'an University, Yan'an, China
| | - Yi-Bo Jia
- Medical College of Yan'an University, Yan'an, China
| | - Shu-Yue Tian
- Medical College of Yan'an University, Yan'an, China
| | - Xi-Chen Zhang
- Key Laboratory of Zoonosis Research by Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Ya-Juan Xue
- Medical College of Yan'an University, Yan'an, China
| | - You-Lei Li
- Medical College of Yan'an University, Yan'an, China
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Pákozdi K, Emri T, Antal K, Pócsi I. Global Transcriptomic Changes Elicited by sodB Deletion and Menadione Exposure in Aspergillus nidulans. J Fungi (Basel) 2023; 9:1060. [PMID: 37998866 PMCID: PMC10671992 DOI: 10.3390/jof9111060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 10/20/2023] [Accepted: 10/25/2023] [Indexed: 11/25/2023] Open
Abstract
Manganese superoxide dismutases (MnSODs) play a pivotal role in the preservation of mitochondrial integrity and function in fungi under various endogenous and exogenous stresses. Deletion of Aspergillus nidulans mnSOD/SodB increased oxidative stress sensitivity and apoptotic cell death rates as well as affected antioxidant enzyme and sterigmatocystin productions, respiration, conidiation and the stress tolerance of conidiospores. The physiological consequences of the lack of sodB were more pronounced during carbon starvation than in the presence of glucose. Lack of SodB also affected the changes in the transcriptome, recorded by high-throughput RNA sequencing, in menadione sodium bisulfite (MSB)-exposed, submerged cultures supplemented with glucose. Surprisingly, the difference between the global transcriptional changes of the ΔsodB mutant and the control strain were relatively small, indicating that the SodB-dependent maintenance of mitochondrial integrity was not essential under these experimental conditions. Owing to the outstanding physiological flexibility of the Aspergilli, certain antioxidant enzymes and endogenous antioxidants together with the reduction in mitochondrial functions compensated well for the lack of SodB. The lack of sodB reduced the growth of surface cultures more than of the submerged culture, which should be considered in future development of fungal disinfection methods.
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Affiliation(s)
- Klaudia Pákozdi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
- Doctoral School of Nutrition and Food Sciences, University of Debrecen, H-4032 Debrecen, Hungary
| | - Tamás Emri
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
| | - Károly Antal
- Department of Zoology, Eszterházy Károly Catholic University, H-3300 Eger, Hungary;
| | - István Pócsi
- Department of Molecular Biotechnology and Microbiology, Institute of Biotechnology, Faculty of Science and Technology, University of Debrecen, H-4032 Debrecen, Hungary;
- HUN-REN–UD Fungal Stress Biology Research Group, H-4032 Debrecen, Hungary
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Transcriptional Stages of Conidia Germination and Associated Genes in Aspergillus flavus: An Essential Role for Redox Genes. Toxins (Basel) 2022; 14:toxins14080560. [PMID: 36006223 PMCID: PMC9412981 DOI: 10.3390/toxins14080560] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/04/2022] [Accepted: 08/12/2022] [Indexed: 12/03/2022] Open
Abstract
Aflatoxin is a threatening mycotoxin primarily present in the agricultural environment, especially in food and feedstuff, and poses significant global health risks. Aflatoxins are produced mainly by Aspergillus flavus. Conidia germination is the first step for A. flavus development. In this study, the transcriptome of A. flavus conidia was analyzed at three different stages of conidia germination, which were characterized by two different microscopes. Dormant conidia grew isotropically with the cell size increasing up to 5 h of after being inoculated in a liquid medium. Conidia changed towards polarized growth from 5 to 10 h of germination, during which germ tubes formed. Moreover, transcriptome analyses revealed that a larger number of genes changed in the isotropic growth stages compared to polarized growth, with 1910 differentially expressed genes (DEGs) up-regulated and 969 DEGs down-regulated in isotropic growth. GO and KEGG pathway analyses and pathway enrichment demonstrated that, in the isotropic growth stage, the top three pathways were translation, amino acid and carbohydrate metabolism. The ribosome was a key pathway in translation, as RPS28e, RPL53 and RPL36e were the top three DEGs. For polarized growth stage, lipid metabolism, amino acid metabolism and carbohydrate metabolism were the top three most active pathways. POX1 from alpha-linolenic acid metabolism was a DEG in lipid metabolism as well. Genes related to the antioxidant system were crucial for conidia germination. Furthermore, RT-PCR results showed the same trends as the transcriptome for redox genes, and essential oils have a significant inhibitory effect on germination rate and redox gene expression. Therefore, redox genes play an important role during germination, and the disruption of redox genes is involved in the mechanism of action of coumalic acid and geraniol against A. flavus spore germination.
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Novel Treatment Approach for Aspergilloses by Targeting Germination. J Fungi (Basel) 2022; 8:jof8080758. [PMID: 35893126 PMCID: PMC9331470 DOI: 10.3390/jof8080758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/03/2022] [Accepted: 07/19/2022] [Indexed: 12/24/2022] Open
Abstract
Germination of conidia is an essential process within the Aspergillus life cycle and plays a major role during the infection of hosts. Conidia are able to avoid detection by the majority of leukocytes when dormant. Germination can cause severe health problems, specifically in immunocompromised people. Aspergillosis is most often caused by Aspergillus fumigatus (A. fumigatus) and affects neutropenic patients, as well as people with cystic fibrosis (CF). These patients are often unable to effectively detect and clear the conidia or hyphae and can develop chronic non-invasive and/or invasive infections or allergic inflammatory responses. Current treatments with (tri)azoles can be very effective to combat a variety of fungal infections. However, resistance against current azoles has emerged and has been increasing since 1998. As a consequence, patients infected with resistant A. fumigatus have a reported mortality rate of 88% to 100%. Especially with the growing number of patients that harbor azole-resistant Aspergilli, novel antifungals could provide an alternative. Aspergilloses differ in defining characteristics, but germination of conidia is one of the few common denominators. By specifically targeting conidial germination with novel antifungals, early intervention might be possible. In this review, we propose several morphotypes to disrupt conidial germination, as well as potential targets. Hopefully, new antifungals against such targets could contribute to disturbing the ability of Aspergilli to germinate and grow, resulting in a decreased fungal burden on patients.
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Anta-Fernández F, Santander-Gordón D, Becerra S, Santamaría R, Díaz-Mínguez JM, Benito EP. Nitric Oxide Metabolism Affects Germination in Botrytis cinerea and Is Connected to Nitrate Assimilation. J Fungi (Basel) 2022; 8:jof8070699. [PMID: 35887455 PMCID: PMC9324006 DOI: 10.3390/jof8070699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 11/16/2022] Open
Abstract
Nitric oxide regulates numerous physiological processes in species from all taxonomic groups. Here, its role in the early developmental stages of the fungal necrotroph Botrytis cinerea was investigated. Pharmacological analysis demonstrated that NO modulated germination, germ tube elongation and nuclear division rate. Experimental evidence indicates that exogenous NO exerts an immediate but transitory negative effect, slowing down germination-associated processes, and that this effect is largely dependent on the flavohemoglobin BCFHG1. The fungus exhibited a “biphasic response” to NO, being more sensitive to low and high concentrations than to intermediate levels of the NO donor. Global gene expression analysis in the wild-type and ΔBcfhg1 strains indicated a situation of strong nitrosative and oxidative stress determined by exogenous NO, which was much more intense in the mutant strain, that the cells tried to alleviate by upregulating several defense mechanisms, including the simultaneous upregulation of the genes encoding the flavohemoglobin BCFHG1, a nitronate monooxygenase (NMO) and a cyanide hydratase. Genetic evidence suggests the coordinated expression of Bcfhg1 and the NMO coding gene, both adjacent and divergently arranged, in response to NO. Nitrate assimilation genes were upregulated upon exposure to NO, and BCFHG1 appeared to be the main enzymatic system involved in the generation of the signal triggering their induction. Comparative expression analysis also showed the influence of NO on other cellular processes, such as mitochondrial respiration or primary and secondary metabolism, whose response could have been mediated by NmrA-like domain proteins.
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Affiliation(s)
- Francisco Anta-Fernández
- Institute for Agribiotechnology Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, 37008 Salamanca, Spain; (F.A.-F.); (S.B.); (J.M.D.-M.)
| | - Daniela Santander-Gordón
- Facultad de Ingeniería y Ciencias Aplicadas (FICA), Carrera de Ingeniería en Biotecnología, Universidad de las Américas (UDLA), Quito 170513, Ecuador;
| | - Sioly Becerra
- Institute for Agribiotechnology Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, 37008 Salamanca, Spain; (F.A.-F.); (S.B.); (J.M.D.-M.)
| | - Rodrigo Santamaría
- Department of Computer Science, University of Salamanca, 37008 Salamanca, Spain;
| | - José María Díaz-Mínguez
- Institute for Agribiotechnology Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, 37008 Salamanca, Spain; (F.A.-F.); (S.B.); (J.M.D.-M.)
| | - Ernesto Pérez Benito
- Institute for Agribiotechnology Research (CIALE), Department of Microbiology and Genetics, University of Salamanca, 37008 Salamanca, Spain; (F.A.-F.); (S.B.); (J.M.D.-M.)
- Correspondence:
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Shankar J. Insight into the metabolic changes during germination of Aspergillus niger conidia using nLC-qTOF. Biologia (Bratisl) 2022. [DOI: 10.1007/s11756-022-01115-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Polozsányi Z, Kaliňák M, Babjak M, Šimkovič M, Varečka Ľ. How to enter the state of dormancy? A suggestion by Trichoderma atroviride conidia. Fungal Biol 2021; 125:934-949. [PMID: 34649680 DOI: 10.1016/j.funbio.2021.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 06/12/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
Abstract
It is generally accepted that conidia, propagules of filamentous fungi, exist in the state of dormancy. This state is defined mostly phenomenologically, e.g., by germination requirements. Its molecular characteristics are scarce and are concentrated on the water or osmolyte content, and/or respiration. However, a question of whether conidia are metabolic or ametabolic forms of life cannot be answered on the basis of available experimental data. In other words, are mature conidia open thermodynamic systems as are mycelia, or do they become closed upon the transition to the dormant state? In this article, we present observations which may help to define the transition of freshly formed conidia to the putative dormant forms using measurements of selected enzyme activities, 1H- and 13C-NMR and LC-MS-metabolomes, and 14C-bicarbonate or 45Ca2+ inward transport. We have found that Trichoderma atroviride and Aspergillus niger conidia arrest the 45Ca2+ uptake during the development stopping thereby the cyclic (i.e., bidirectional) Ca2+ flow existing in vegetative mycelia and conidia of T. atroviride across the cytoplasmic membrane. Furthermore, we have found that the activity of α-ketoglutarate dehydrogenase was rendered completely inactive after 3 weeks from the conidia formation unlike of other central carbon metabolism enzymes. This may explain the loss of conidial respiration. Finally, we found that conidia take up the H14CO3- and convert it into few stable compounds within 80 d of maturation, with minor quantitative differences in the extent of this process. The uptake of H13CO3- confirmed these observation and demonstrated the incorporation of H13CO3- even in the absence of exogenous substrates. These results suggest that T. atroviride conidia remain metabolically active during first ten weeks of maturation. Under these circumstances, their metabolism displays features similar to those of chemoautotrophic microorganisms. However, the Ca2+ homeostasis changed from the open to the closed thermodynamic state during the early period of conidial maturation. These results may be helpful for studying the conidial ageing and/or maturation, and for defining the conidial dormant state in biochemical terms.
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Affiliation(s)
- Zoltán Polozsányi
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Michal Kaliňák
- Central Laboratories, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Matej Babjak
- Department of Organic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
| | - Martin Šimkovič
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia.
| | - Ľudovít Varečka
- Institute of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 812 37, Bratislava, Slovakia
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Transcription in fungal conidia before dormancy produces phenotypically variable conidia that maximize survival in different environments. Nat Microbiol 2021; 6:1066-1081. [PMID: 34183813 DOI: 10.1038/s41564-021-00922-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 05/18/2021] [Indexed: 02/05/2023]
Abstract
Fungi produce millions of clonal asexual conidia (spores) that remain dormant until favourable conditions occur. Conidia contain abundant stable messenger RNAs but the mechanisms underlying the production of these transcripts and their composition and functions are unknown. Here, we report that the conidia of three filamentous fungal species (Aspergillus nidulans, Aspergillus fumigatus, Talaromyces marneffei) are transcriptionally active and can synthesize mRNAs. We find that transcription in fully developed conidia is modulated in response to changes in the environment until conidia leave the developmental structure. Environment-specific transcriptional responses can alter conidial content (mRNAs, proteins and secondary metabolites) and change gene expression when dormancy is broken. Conidial transcription affects the fitness and capabilities of fungal cells after germination, including stress and antifungal drug (azole) resistance, mycotoxin and secondary metabolite production and virulence. The transcriptional variation that we characterize in fungal conidia explains how genetically identical conidia mature into phenotypically variable conidia. We find that fungal conidia prepare for the future by synthesizing and storing transcripts according to environmental conditions present before dormancy.
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Baltussen TJH, Coolen JPM, Verweij PE, Dijksterhuis J, Melchers WJG. Identifying Conserved Generic Aspergillus spp. Co-Expressed Gene Modules Associated with Germination Using Cross-Platform and Cross-Species Transcriptomics. J Fungi (Basel) 2021; 7:270. [PMID: 33916245 PMCID: PMC8067318 DOI: 10.3390/jof7040270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/27/2021] [Accepted: 03/29/2021] [Indexed: 12/26/2022] Open
Abstract
Aspergillus spp. is an opportunistic human pathogen that may cause a spectrum of pulmonary diseases. In order to establish infection, inhaled conidia must germinate, whereby they break dormancy, start to swell, and initiate a highly polarized growth process. To identify critical biological processes during germination, we performed a cross-platform, cross-species comparative analysis of germinating A. fumigatus and A. niger conidia using transcriptional data from published RNA-Seq and Affymetrix studies. A consensus co-expression network analysis identified four gene modules associated with stages of germination. These modules showed numerous shared biological processes between A. niger and A. fumigatus during conidial germination. Specifically, the turquoise module was enriched with secondary metabolism, the black module was highly enriched with protein synthesis, the darkgreen module was enriched with protein fate, and the blue module was highly enriched with polarized growth. More specifically, enriched functional categories identified in the blue module were vesicle formation, vesicular transport, tubulin dependent transport, actin-dependent transport, exocytosis, and endocytosis. Genes important for these biological processes showed similar expression patterns in A. fumigatus and A. niger, therefore, they could be potential antifungal targets. Through cross-platform, cross-species comparative analysis, we were able to identify biologically meaningful modules shared by A. fumigatus and A. niger, which underscores the potential of this approach.
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Affiliation(s)
- Tim J. H. Baltussen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Jordy P. M. Coolen
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Paul E. Verweij
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
| | - Jan Dijksterhuis
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands
| | - Willem J. G. Melchers
- Department of Medical Microbiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (J.P.M.C.); (P.E.V.); (W.J.G.M.)
- Center of Expertise in Mycology Radboudumc/CWZ, 6532 SZ Nijmegen, The Netherlands
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van Leeuwe TM, Wattjes J, Niehues A, Forn-Cuní G, Geoffrion N, Mélida H, Arentshorst M, Molina A, Tsang A, Meijer AH, Moerschbacher BM, Punt PJ, Ram AF. A seven-membered cell wall related transglycosylase gene family in Aspergillus niger is relevant for cell wall integrity in cell wall mutants with reduced α-glucan or galactomannan. Cell Surf 2020; 6:100039. [PMID: 32743151 PMCID: PMC7389268 DOI: 10.1016/j.tcsw.2020.100039] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/12/2020] [Accepted: 03/17/2020] [Indexed: 11/05/2022] Open
Abstract
Chitin is an important fungal cell wall component that is cross-linked to β-glucan for structural integrity. Acquisition of chitin to glucan cross-links has previously been shown to be performed by transglycosylation enzymes in Saccharomyces cerevisiae, called Congo Red hypersensitive (Crh) enzymes. Here, we characterized the impact of deleting all seven members of the crh gene family (crhA-G) in Aspergillus niger on cell wall integrity, cell wall composition and genome-wide gene expression. In this study, we show that the seven-fold crh knockout strain shows slightly compact growth on plates, but no increased sensitivity to cell wall perturbing compounds. Additionally, we found that the cell wall composition of this knockout strain was virtually identical to that of the wild type. In congruence with these data, genome-wide expression analysis revealed very limited changes in gene expression and no signs of activation of the cell wall integrity response pathway. However, deleting the entire crh gene family in cell wall mutants that are deficient in either galactofuranose or α-glucan, mainly α-1,3-glucan, resulted in a synthetic growth defect and an increased sensitivity towards Congo Red compared to the parental strains, respectively. Altogether, these results indicate that loss of the crh gene family in A. niger does not trigger the cell wall integrity response, but does play an important role in ensuring cell wall integrity in mutant strains with reduced galactofuranose or α-glucan.
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Affiliation(s)
- Tim M. van Leeuwe
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Jasper Wattjes
- Institute for Biology and Biotechnology of Plants, University of Muenster, Schlossplatz 8, 48143 Münster, Germany
| | - Anna Niehues
- Institute for Biology and Biotechnology of Plants, University of Muenster, Schlossplatz 8, 48143 Münster, Germany
| | - Gabriel Forn-Cuní
- Leiden University, Institute of Biology Leiden, Animal Science and Health, Einsteinweg 55, 2333CC Leiden, the Netherlands
| | - Nicholas Geoffrion
- Centre for Structural and Functional Genomics, Concordia University, Quebec H4B1R6, Canada
| | - Hugo Mélida
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo-UPM, 28223 Pozuelo de Alarcón (Madrid), Spain
| | - Mark Arentshorst
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
| | - Antonio Molina
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)-Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo-UPM, 28223 Pozuelo de Alarcón (Madrid), Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040 Madrid, Spain
| | - Adrian Tsang
- Centre for Structural and Functional Genomics, Concordia University, Quebec H4B1R6, Canada
| | - Annemarie H. Meijer
- Leiden University, Institute of Biology Leiden, Animal Science and Health, Einsteinweg 55, 2333CC Leiden, the Netherlands
| | - Bruno M. Moerschbacher
- Institute for Biology and Biotechnology of Plants, University of Muenster, Schlossplatz 8, 48143 Münster, Germany
| | - Peter J. Punt
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
- Dutch DNA Biotech, Hugo R Kruytgebouw 4-Noord, Padualaan 8, 3584 CH Utrecht, the Netherlands
| | - Arthur F.J. Ram
- Leiden University, Institute of Biology Leiden, Molecular Microbiology and Biotechnology, Sylviusweg 72, 2333 BE Leiden, the Netherlands
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Kalampokis IF, Erban A, Amillis S, Diallinas G, Kopka J, Aliferis KA. Untargeted metabolomics as a hypothesis-generation tool in plant protection product discovery: Highlighting the potential of trehalose and glycerol metabolism of fungal conidiospores as novel targets. Metabolomics 2020; 16:79. [PMID: 32601735 DOI: 10.1007/s11306-020-01699-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/15/2020] [Indexed: 12/11/2022]
Abstract
INTRODUCTION The production of high quality and safe food represents a main priority for the agri-food sector in the effort to sustain the exponentially growing human population. Nonetheless, there are major challenges that require the discovery of new, alternative, and improved plant protection products (PPPs). Focusing on fungal plant pathogens, the dissection of mechanisms that are essential for their survival provides insights that could be exploited towards the achievement of the aforementioned aim. In this context, the germination of fungal spores, which are essential structures for their dispersal, survival, and pathogenesis, represents a target of high potential for PPPs. To the best of our knowledge, no PPPs that target the germination of fungal spores currently exist. OBJECTIVES Within this context, we have mined for changes in the metabolite profiles of the model fungus Aspergillus nidulans FGSC A4 conidiospores during germination, in an effort to discover key metabolites and reactions that could potentially become targets of PPPs. METHODS Untargeted GC/EI-TOF/MS metabolomics and multivariate analyses were employed to monitor time-resolved changes in the metabolomes of germinating A. nidulans conidiospores. RESULTS Analyses revealed that trehalose hydrolysis plays a pivotal role in conidiospore germination and highlighted the osmoregulating role of the sugar alcohols, glycerol, and mannitol. CONCLUSION The ineffectiveness to introduce active ingredients that exhibit new mode(s)-of-action as fungicides, dictates the urge for the discovery of PPPs, which could be exploited to combat major plant protection issues. Based on the crucial role of trehalose hydrolysis in conidiospore dormancy breakage, and the subsequent involvement of glycerol in their germination, it is plausible to suggest their biosynthesis pathways as potential novel targets for the next-generation antifungal PPPs. Our study confirmed the applicability of untargeted metabolomics as a hypothesis-generation tool in PPPs' research and discovery.
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Affiliation(s)
- Ioannis F Kalampokis
- Laboratory of Pesticide Science, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece
| | - Alexander Erban
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Sotirios Amillis
- Department of Biology, National and Kapodistrian University of Athens, 15784, Panepistimioupolis, Athens, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, 15784, Panepistimioupolis, Athens, Greece
| | - Joachim Kopka
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Wissenschaftspark Golm, Am Mühlenberg 1, 14476, Potsdam, Germany
| | - Konstantinos A Aliferis
- Laboratory of Pesticide Science, Agricultural University of Athens, Iera Odos 75, 118 55, Athens, Greece.
- Department of Plant Science, McGill University, 21111 Lakeshore Road, Montréal, H9X 3V9, Canada.
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12
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Abstract
Aspergilli produce conidia for reproduction or to survive hostile conditions, and they are highly effective in the distribution of conidia through the environment. In immunocompromised individuals, inhaled conidia can germinate inside the respiratory tract, which may result in invasive pulmonary aspergillosis. The management of invasive aspergillosis has become more complex, with new risk groups being identified and the emergence of antifungal resistance. Patient survival is threatened by these developments, stressing the need for alternative therapeutic strategies. As germination is crucial for infection, prevention of this process might be a feasible approach. A broader understanding of conidial germination is important to identify novel antigermination targets. In this review, we describe conidial resistance against various stresses, transition from dormant conidia to hyphal growth, the underlying molecular mechanisms involved in germination of the most common Aspergillus species, and promising antigermination targets. Germination of Aspergillus is characterized by three morphotypes: dormancy, isotropic growth, and polarized growth. Intra- and extracellular proteins play an important role in the protection against unfavorable environmental conditions. Isotropically expanding conidia remodel the cell wall, and biosynthetic machineries are needed for cellular growth. These biosynthetic machineries are also important during polarized growth, together with tip formation and the cell cycle machinery. Genes involved in isotropic and polarized growth could be effective antigermination targets. Transcriptomic and proteomic studies on specific Aspergillus morphotypes will improve our understanding of the germination process and allow discovery of novel antigermination targets and biomarkers for early diagnosis and therapy.
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13
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van den Brule T, Punt M, Teertstra W, Houbraken J, Wösten H, Dijksterhuis J. The most heat-resistant conidia observed to date are formed by distinct strains of Paecilomyces variotii. Environ Microbiol 2019; 22:986-999. [PMID: 31444981 PMCID: PMC7065192 DOI: 10.1111/1462-2920.14791] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/22/2019] [Accepted: 08/22/2019] [Indexed: 12/20/2022]
Abstract
Fungi colonize habitats by means of spores. These cells are stress‐resistant compared with growing fungal cells. Fungal conidia, asexual spores, formed by cosmopolitan fungal genera like Penicillium, Aspergillus and Peacilomyces are dispersed by air. They are present in places where food products are stored and as a result, they cause food spoilage. Here, we determined the heterogeneity of heat resistance of conidia between and within strains of Paecilomyces variotii, a spoiler of foods such as margarine, fruit juices, canned fruits and non‐carbonized sodas. Out of 108 strains, 31 isolates showed a conidial survival >10% after a 10‐min‐heat treatment at 59°C. Three strains with different conidial heat resistance were selected for further phenotyping. Conidia of DTO 212‐C5 and DTO 032‐I3 showed 0.3% and 2.6% survival in the screening respectively, while survival of DTO 217‐A2 conidia was >10%. The decimal reduction times of these strains at 60°C (D60 value) were 3.7 ± 0.08, 5.5 ± 0.35 and 22.9 ± 2.00 min respectively. Further in‐depth analysis revealed that the three strains showed differences in morphology, spore size distributions, compatible solute compositions and growth under salt stress. Conidia of DTO 217‐A2 are the most heat‐resistant reported so far. The ecological consequences of this heterogeneity of resistance, including food spoilage, are discussed.
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Affiliation(s)
- Tom van den Brule
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Department of Applied and Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Maarten Punt
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Utrecht University, Molecular Microbiology, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Wieke Teertstra
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Utrecht University, Molecular Microbiology, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Jos Houbraken
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Department of Applied and Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Han Wösten
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Utrecht University, Molecular Microbiology, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Jan Dijksterhuis
- TiFN, P.O. Box 557, 6700 AN, Wageningen, The Netherlands.,Department of Applied and Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
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14
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Sephton-Clark PCS, Muñoz JF, Ballou ER, Cuomo CA, Voelz K. Pathways of Pathogenicity: Transcriptional Stages of Germination in the Fatal Fungal Pathogen Rhizopus delemar. mSphere 2018; 3:e00403-18. [PMID: 30258038 PMCID: PMC6158513 DOI: 10.1128/msphere.00403-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 08/22/2018] [Indexed: 12/19/2022] Open
Abstract
Rhizopus delemar is an invasive fungal pathogen responsible for the frequently fatal disease mucormycosis. Germination, a crucial mechanism by which infectious spores of Rhizopus delemar cause disease, is a key developmental process that transforms the dormant spore state into a vegetative one. The molecular mechanisms that underpin this transformation may be key to controlling mucormycosis; however, the regulation of germination remains poorly understood. This study describes the phenotypic and transcriptional changes that take place over the course of germination. This process is characterized by four distinct stages: dormancy, isotropic swelling, germ tube emergence, and hyphal growth. Dormant spores are shown to be transcriptionally unique, expressing a subset of transcripts absent in later developmental stages. A large shift in the expression profile is prompted by the initiation of germination, with genes involved in respiration, chitin, cytoskeleton, and actin regulation appearing to be important for this transition. A period of transcriptional consistency can be seen throughout isotropic swelling, before the transcriptional landscape shifts again at the onset of hyphal growth. This study provides a greater understanding of the regulation of germination and highlights processes involved in transforming Rhizopus delemar from a single-cellular to multicellular organism.IMPORTANCE Germination is key to the growth of many organisms, including fungal spores. Mucormycete spores exist abundantly within the environment and germinate to form hyphae. These spores are capable of infecting immunocompromised individuals, causing the disease mucormycosis. Germination from spore to hyphae within patients leads to angioinvasion, tissue necrosis, and often fatal infections. This study advances our understanding of how spore germination occurs in the mucormycetes, identifying processes we may be able to inhibit to help prevent or treat mucormycosis.
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Affiliation(s)
- Poppy C S Sephton-Clark
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Jose F Muñoz
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Elizabeth R Ballou
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
| | - Christina A Cuomo
- Infectious Disease and Microbiome Program, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Kerstin Voelz
- Institute for Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
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15
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Genomic Analysis of the Insect-Killing Fungus Beauveria bassiana JEF-007 as a Biopesticide. Sci Rep 2018; 8:12388. [PMID: 30120392 PMCID: PMC6098154 DOI: 10.1038/s41598-018-30856-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/07/2018] [Indexed: 02/07/2023] Open
Abstract
Insect-killing fungi have high potential in pest management. A deeper insight into the fungal genes at the whole genome level is necessary to understand the inter-species or intra-species genetic diversity of fungal genes, and to select excellent isolates. In this work, we conducted a whole genome sequencing of Beauveria bassiana (Bb) JEF-007 and characterized pathogenesis-related features and compared with other isolates including Bb ARSEF2860. A large number of Bb JEF-007 genes showed high identity with Bb ARSEF2860, but some genes showed moderate or low identity. The two Bb isolates showed a significant difference in vegetative growth, antibiotic-susceptibility, and virulence against Tenebrio molitor larvae. When highly identical genes between the two Bb isolates were subjected to real-time PCR, their transcription levels were different, particularly in heat shock protein 30 (hsp30) gene which is related to conidial thermotolerance. In several B. bassiana isolates, chitinases and trypsin-like protease genes involved in pathogenesis were highly conserved, but other genes showed noticeable sequence variation within the same species. Given the transcriptional and genetic diversity in B. bassiana, a selection of virulent isolates with industrial advantages is a pre-requisite, and this genetic approach could support the development of excellent biopesticides with intellectual property protection.
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16
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Xie H, Ma Q, Wei DZ, Wang FQ. Transcriptomic analysis of Aspergillus niger strains reveals the mechanism underlying high citric acid productivity. BIORESOUR BIOPROCESS 2018. [DOI: 10.1186/s40643-018-0208-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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17
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Baltussen TJH, Coolen JPM, Zoll J, Verweij PE, Melchers WJG. Gene co-expression analysis identifies gene clusters associated with isotropic and polarized growth in Aspergillus fumigatus conidia. Fungal Genet Biol 2018; 116:62-72. [PMID: 29705402 DOI: 10.1016/j.fgb.2018.04.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 12/18/2022]
Abstract
Aspergillus fumigatus is a saprophytic fungus that extensively produces conidia. These microscopic asexually reproductive structures are small enough to reach the lungs. Germination of conidia followed by hyphal growth inside human lungs is a key step in the establishment of infection in immunocompromised patients. RNA-Seq was used to analyze the transcriptome of dormant and germinating A. fumigatus conidia. Construction of a gene co-expression network revealed four gene clusters (modules) correlated with a growth phase (dormant, isotropic growth, polarized growth). Transcripts levels of genes encoding for secondary metabolites were high in dormant conidia. During isotropic growth, transcript levels of genes involved in cell wall modifications increased. Two modules encoding for growth and cell cycle/DNA processing were associated with polarized growth. In addition, the co-expression network was used to identify highly connected intermodular hub genes. These genes may have a pivotal role in the respective module and could therefore be compelling therapeutic targets. Generally, cell wall remodeling is an important process during isotropic and polarized growth, characterized by an increase of transcripts coding for hyphal growth and cell cycle/DNA processing when polarized growth is initiated.
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Affiliation(s)
- Tim J H Baltussen
- (a)Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; (b)Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands.
| | - Jordy P M Coolen
- (a)Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; (b)Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Jan Zoll
- (a)Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; (b)Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Paul E Verweij
- (a)Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; (b)Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Willem J G Melchers
- (a)Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands; (b)Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
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18
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Oda K, Bignell E, Kang SE, Momany M. Transcript levels of the Aspergillus fumigatus Cdc42 module, polarisome, and septin genes show little change from dormancy to polarity establishment. Med Mycol 2018; 55:445-452. [PMID: 27664992 DOI: 10.1093/mmy/myw085] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/31/2016] [Indexed: 12/19/2022] Open
Abstract
Aspergillus fumigatus is the most common airborne pathogen causing fatal mycoses in immunocompromised patients. During the first 8 hours of development A. fumigatus conidia break dormancy, expand isotopically, establish an axis of polarity, and begin to extend germ tubes in a polar manner. The transition from isotropic to polar growth is critical for tissue invasion and pathogenesis. In the current work, we used two-color microarrays to examine the A. fumigatus transcriptome during early development, focusing on the isotropic to polar switch. The most highly regulated transcripts in the isotropic to polar switch did not include known polarity genes. Transcripts encoding the Cdc42 module, polarisome components, and septins, known to be critical players in polarity, showed relatively steady levels during the isotropic to polar switch. Indeed, these transcripts were present in dormant conidia, and their levels changed little from dormancy through germ tube emergence. Not only did the isotropic to polar switch show little change in the expression of key polarity genes of the Cdc42 module, polarisome, and septins, it also showed the lowest overall levels of both up- and downregulation in early development.
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Affiliation(s)
- Ken Oda
- Fungal Biology Group and Department of Plant Biology, University of Georgia, Athens, Georgia, USA 30602.,Current address: National Research Institute of Brewing (NRIB), Hiroshima, Japan 739-0046
| | - Elaine Bignell
- Fungal Biology Group and Department of Plant Biology, University of Georgia, Athens, Georgia, USA 30602
| | - S Earl Kang
- Fungal Biology Group and Department of Plant Biology, University of Georgia, Athens, Georgia, USA 30602
| | - Michelle Momany
- Fungal Biology Group and Department of Plant Biology, University of Georgia, Athens, Georgia, USA 30602
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19
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Peng Y, Zhang H, Xu M, Tan MW. A Tet-Off gene expression system for validation of antifungal drug targets in a murine invasive pulmonary aspergillosis model. Sci Rep 2018; 8:443. [PMID: 29323188 PMCID: PMC5765126 DOI: 10.1038/s41598-017-18868-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/18/2017] [Indexed: 12/20/2022] Open
Abstract
Aspergillus fumigatus is one of the major causes of invasive pulmonary aspergillosis in immunocompromised patients. Novel antifungal therapy is in urgent need due to emerging resistance and adverse toxicity of current antifungal drugs. Gene products that are essential for Aspergillus viability during infection are attractive drug targets. To characterize these genes in vivo we developed a Tet-Off gene expression system in A. fumigatus, whereby the administration of doxycycline resulted in down regulation of the gene whose expression is under the control of the Tet-Off promoter. We tested the system on two potential drug targets, inosine 5′-monophosphate dehydrogenase (IMPDH) and L-ornithine N5-oxygenase (sidA) in a murine invasive pulmonary aspergillosis model. We show that depletion of IMPDH attenuated but did not completely abolish virulence in vivo whereas turning off the expression of sidA, which is required for iron acquisition, resulted in avirulence. We also investigated whether sidA expression could be controlled in a time-dependent manner in mice. Our results demonstrated that timing of doxycycline administration dramatically affects survival rate, suggesting that this genetic system can be used for testing whether an antifungal drug target is critical for fungal growth post-infection.
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Affiliation(s)
- Yutian Peng
- Infectious Diseases Department, Genentech Inc., South San Francisco, California, 94080, USA.
| | - Hua Zhang
- Translational Immunology Department, Genentech Inc., South San Francisco, California, 94080, USA
| | - Min Xu
- Translational Immunology Department, Genentech Inc., South San Francisco, California, 94080, USA
| | - Man-Wah Tan
- Infectious Diseases Department, Genentech Inc., South San Francisco, California, 94080, USA.
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20
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Jirakkakul J, Roytrakul S, Srisuksam C, Swangmaneecharern P, Kittisenachai S, Jaresitthikunchai J, Punya J, Prommeenate P, Senachak J, So L, Tachaleat A, Tanticharoen M, Cheevadhanarak S, Wattanachaisaereekul S, Amnuaykanjanasin A. Culture degeneration in conidia of Beauveria bassiana and virulence determinants by proteomics. Fungal Biol 2017; 122:156-171. [PMID: 29458719 DOI: 10.1016/j.funbio.2017.12.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 12/04/2017] [Accepted: 12/15/2017] [Indexed: 01/18/2023]
Abstract
The quality of Beauveria bassiana conidia directly affects the virulence against insects. In this study, continuous subculturing of B. bassiana on both rice grains and potato dextrose agar (PDA) resulted in 55 and 49 % conidial yield reduction after 12 passages and 68 and 60 % virulence reduction after 20 and 12 passages at four d post-inoculation, respectively. The passage through Tenebrio molitor and Spodoptera exigua restored the virulence of rice and PDA subcultures, respectively. To explore the molecular mechanisms underlying the conidial quality and the decline of virulence after multiple subculturing, we investigated the conidial proteomic changes. Successive subculturing markedly increased the protein levels in oxidative stress response, autophagy, amino acid homeostasis, and apoptosis, but decreased the protein levels in DNA repair, ribosome biogenesis, energy metabolism, and virulence. The nitro blue tetrazolium assay verified that the late subculture's colony and conidia had a higher oxidative stress level than the early subculture. A 2A-type protein phosphatase and a Pleckstrin homology domain protein Slm1, effector proteins of the target of rapamycin (TOR) complex 1 and 2, respectively, were dramatically increased in the late subculture. These results suggest that TOR signalling might be associated with ageing in B. bassiana late subculture, in turn affecting its physiological characteristics and virulence.
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Affiliation(s)
- Jiraporn Jirakkakul
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand
| | - Sittiruk Roytrakul
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Chettida Srisuksam
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Pratchya Swangmaneecharern
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Suthathip Kittisenachai
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Janthima Jaresitthikunchai
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Juntira Punya
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Peerada Prommeenate
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Jittisak Senachak
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand
| | - Laihong So
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Kowloon, Hong Kong
| | - Anuwat Tachaleat
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand
| | - Morakot Tanticharoen
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand
| | - Supapon Cheevadhanarak
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand
| | - Songsak Wattanachaisaereekul
- Pilot Plant Development and Training Institute, King Mongkut's University of Technology Thonburi (KMUTT), Bangkhuntien, Bangkok 10150, Thailand.
| | - Alongkorn Amnuaykanjanasin
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), 113 Paholyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
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21
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Sephton-Clark PCS, Voelz K. Spore Germination of Pathogenic Filamentous Fungi. ADVANCES IN APPLIED MICROBIOLOGY 2017; 102:117-157. [PMID: 29680124 DOI: 10.1016/bs.aambs.2017.10.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Fungi, algae, plants, protozoa, and bacteria are all known to form spores, especially hardy and ubiquitous propagation structures that are also often the infectious agents of diseases. Spores can survive for thousands of years, frozen in the permafrost (Kochkina et al., 2012), with the oldest viable spores extracted after 250 million years from salt crystals (Vreeland, Rosenzweig, & Powers, 2000). Their resistance to high levels of UV, desiccation, pressure, heat, and cold enables the survival of spores in the harshest conditions (Setlow, 2016). For example, Bacillus subtilis spores can survive and remain viable after experiencing conditions similar to those on Mars (Horneck et al., 2012). Spores are disseminated through environmental factors. Wind, water, or animal carriage allow spores to be spread ubiquitously throughout the environment. Spores will break dormancy and begin to germinate once exposed to favorable conditions. Germination is the mechanism that converts the spore from a dormant biological organism to one that grows vegetatively and is capable of either sexual or asexual reproduction. The process of germination has been well studied in plants, moss, bacteria, and many fungi (Hohe & Reski, 2005; Huang & Hull, 2017; Vesty et al., 2016). Unfortunately, information on the complex signaling involved in the regulation of germination, particularly in fungi remains lacking. This chapter will discuss germination of fungal spores covering our current understanding of the regulation, signaling, outcomes, and implications of germination of pathogenic fungal spores. Owing to the morphological similarities between the spore-hyphal and yeast-hyphal transition and their relevance for disease progression, relevant aspects of fungal dimorphism will be discussed alongside spore germination in this chapter.
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Affiliation(s)
- Poppy C S Sephton-Clark
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Kerstin Voelz
- School of Biosciences, Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom.
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22
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Sui YF, Ouyang LM, Chu J, Cao WQ, liang LF, Zhuang YP, Cheng S, Norrman H, Zhang SL, zhang GY. Global transcriptional response of Aspergillus niger in the process of glucoamylase fermentation. BIORESOUR BIOPROCESS 2017. [DOI: 10.1186/s40643-017-0160-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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23
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Sporulation: how to survive on planet Earth (and beyond). Curr Genet 2017; 63:831-838. [PMID: 28421279 DOI: 10.1007/s00294-017-0694-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 04/06/2017] [Accepted: 04/08/2017] [Indexed: 02/07/2023]
Abstract
Sporulation is a strategy widely utilized by a wide variety of organisms to adapt to changes in their individual environmental niches and survive in time and/or space until they encounter conditions acceptable for vegetative growth. The spores produced by bacteria have been the subjects of extensive studies, and several systems such as Bacillus subtilis have provided ample opportunities to understand the molecular basis of spore biogenesis and germination. In contrast, the spores of other microbes, such as fungi, are relatively poorly understood. Studies of sporulation in model systems such as Saccharomyces cerevisiae and Aspergillus nidulans have established a basis for investigating eukaryotic spores, but very little is known at the molecular level about how spores function. This is especially true among the spores of human fungal pathogens such as the most common cause of fatal fungal disease, Cryptococcus neoformans. Recent proteomic studies are helping to determine the molecular mechanisms by which pathogenic fungal spores are formed, persist and germinate into actively growing agents of human disease.
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24
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Chakdar H, Singha A, Satya P. New Generation Markers for Fingerprinting and Structural Analysis of Fungal Community. Fungal Biol 2017. [DOI: 10.1007/978-3-319-34106-4_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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25
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Maturation of conidia on conidiophores of Aspergillus niger. Fungal Genet Biol 2017; 98:61-70. [DOI: 10.1016/j.fgb.2016.12.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 12/12/2016] [Accepted: 12/19/2016] [Indexed: 11/23/2022]
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26
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Wu Y, Li YH, Yu SB, Li WG, Liu XS, Zhao L, Lu JX. A Genome-Wide Transcriptional Analysis of Yeast-Hyphal Transition in Candida tropicalis by RNA-Seq. PLoS One 2016; 11:e0166645. [PMID: 27851809 PMCID: PMC5112795 DOI: 10.1371/journal.pone.0166645] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 11/01/2016] [Indexed: 12/28/2022] Open
Abstract
Candida tropicalis is considered as the leading pathogen in nosocomial fungemia and hepatosplenic fungal infections in patients with cancer, particularly in leukemia. The yeast-filament transition is required for virulent infection by Candida. Several studies have explored the genome-wide transcription profile of Candida, however, no report on the transcriptional profile of C. tropicalis under yeast-filament transition has been published. In this study, the transcriptomes of three C. tropicalis isolates with different adhesion and biofilm formation abilities, identified in our previous studies, were analyzed in both the yeast and filament states using RNA-Seq. Differentially expressed genes were found for each isolate during the transition. A total of 115 genes were up- or down- regulated in the two hyphal-producing isolates (ZRCT 4 and ZRCT 45). Among these differentially expressed genes, only two were down-regulated during the yeast-filament transition. Furthermore, six filament-associated genes were up-regulated in the hyphae-producing isolates. According to Candida Hypha Growth Database established in this study, 331 hyphae- related genes were discovered in C. tropicalis. ALS1 and ALS3 were down-regulated and up-regulated, respectively, during filamentous growth of C. tropicalis. These findings proved a better understanding of gene expression dynamics during the yeast-filament transition in C. tropicalis.
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Affiliation(s)
- Yuan Wu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China
| | - Yin-hu Li
- Microbial Research Department, BGI-Shenzhen, Main building, Beishan Industry Zone, Yantian District, Shenzhen, China
| | - Shuan-bao Yu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China
| | - Wen-ge Li
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China
| | - Xiao-shu Liu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China
| | - Lei Zhao
- Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, United States of America
| | - Jin-xing Lu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Chang bai Road 155, Chang ping District, Beijing, China
- * E-mail:
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A Transcriptome Meta-Analysis Proposes Novel Biological Roles for the Antifungal Protein AnAFP in Aspergillus niger. PLoS One 2016; 11:e0165755. [PMID: 27835655 PMCID: PMC5106034 DOI: 10.1371/journal.pone.0165755] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 10/17/2016] [Indexed: 02/06/2023] Open
Abstract
Understanding the genetic, molecular and evolutionary basis of cysteine-stabilized antifungal proteins (AFPs) from fungi is important for understanding whether their function is mainly defensive or associated with fungal growth and development. In the current study, a transcriptome meta-analysis of the Aspergillus niger γ-core protein AnAFP was performed to explore co-expressed genes and pathways, based on independent expression profiling microarrays covering 155 distinct cultivation conditions. This analysis uncovered that anafp displays a highly coordinated temporal and spatial transcriptional profile which is concomitant with key nutritional and developmental processes. Its expression profile coincides with early starvation response and parallels with genes involved in nutrient mobilization and autophagy. Using fluorescence- and luciferase reporter strains we demonstrated that the anafp promoter is active in highly vacuolated compartments and foraging hyphal cells during carbon starvation with CreA and FlbA, but not BrlA, as most likely regulators of anafp. A co-expression network analysis supported by luciferase-based reporter assays uncovered that anafp expression is embedded in several cellular processes including allorecognition, osmotic and oxidative stress survival, development, secondary metabolism and autophagy, and predicted StuA and VelC as additional regulators. The transcriptomic resources available for A. niger provide unparalleled resources to investigate the function of proteins. Our work illustrates how transcriptomic meta-analyses can lead to hypotheses regarding protein function and predict a role for AnAFP during slow growth, allorecognition, asexual development and nutrient recycling of A. niger and propose that it interacts with the autophagic machinery to enable these processes.
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28
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Nguyen Van Long N, Vasseur V, Coroller L, Dantigny P, Le Panse S, Weill A, Mounier J, Rigalma K. Temperature, water activity and pH during conidia production affect the physiological state and germination time of Penicillium species. Int J Food Microbiol 2016; 241:151-160. [PMID: 27780083 DOI: 10.1016/j.ijfoodmicro.2016.10.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 09/28/2016] [Accepted: 10/17/2016] [Indexed: 11/25/2022]
Abstract
Conidial germination and mycelial growth are generally studied with conidia produced under optimal conditions to increase conidial yield. Nonetheless, the physiological state of such conidia most likely differs from those involved in spoilage of naturally contaminated food. The present study aimed at investigating the impact of temperature, pH and water activity (aw) during production of conidia on the germination parameters and compatible solutes of conidia of Penicillium roqueforti and Penicillium expansum. Low temperature (5°C) and reduced aw (0.900 aw) during sporulation significantly reduced conidial germination times whereas the pH of the sporulation medium only had a slight effect at the tested values (2.5, 8.0). Conidia of P. roqueforti produced at 5°C germinated up to 45h earlier than those produced at 20°C. Conidia of P. roqueforti and P. expansum produced at 0.900 aw germinated respectively up to 8h and 3h earlier than conidia produced at 0.980 aw. Furthermore, trehalose and mannitol assessments suggested that earlier germination might be related to delayed conidial maturation even though no ultra-structural modifications were observed by transmission electron microscopy. Taken together, these results highlight the importance of considering environmental conditions during sporulation in mycological studies. The physiological state of fungal conidia should be taken into account to design challenge tests or predictive mycology studies. This knowledge may also be of interest to improve the germination capacity of fungal cultures commonly used in fermented foods.
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Affiliation(s)
- Nicolas Nguyen Van Long
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Valérie Vasseur
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Louis Coroller
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, UMT Spore Risk, IUT Quimper, 6 rue de l'Université, 29334 Quimper, France
| | - Philippe Dantigny
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Sophie Le Panse
- Plateforme Merimage, Station Biologique de Roscoff, CNRS-UPMC, Place Georges Teissier, CS90074, 29688 Roscoff, Cedex, France
| | - Amélie Weill
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Jérôme Mounier
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Karim Rigalma
- Université de Brest, EA 3882, Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Technopôle Brest-Iroise, 29280 Plouzané, France.
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Novodvorska M, Stratford M, Blythe MJ, Wilson R, Beniston RG, Archer DB. Metabolic activity in dormant conidia of Aspergillus niger and developmental changes during conidial outgrowth. Fungal Genet Biol 2016; 94:23-31. [PMID: 27378203 PMCID: PMC4981222 DOI: 10.1016/j.fgb.2016.07.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/21/2016] [Accepted: 07/01/2016] [Indexed: 01/15/2023]
Abstract
Resting conidia are demonstrated to be metabolically active. After triggering of conidial outgrowth fermentation occurs, followed by respiration. Sorbic acid inhibits O2 uptake and delays the onset of respiration.
The early stages of development of Aspergillus niger conidia during outgrowth were explored by combining genome-wide gene expression analysis (RNAseq), proteomics, Warburg manometry and uptake studies. Resting conidia suspended in water were demonstrated for the first time to be metabolically active as low levels of oxygen uptake and the generation of carbon dioxide were detected, suggesting that low-level respiratory metabolism occurs in conidia for maintenance. Upon triggering of spore germination, generation of CO2 increased dramatically. For a short period, which coincided with mobilisation of the intracellular polyol, trehalose, there was no increase in uptake of O2 indicating that trehalose was metabolised by fermentation. Data from genome-wide mRNA profiling showed the presence of transcripts associated with fermentative and respiratory metabolism in resting conidia. Following triggering of conidial outgrowth, there was a clear switch to respiration after 25 min, confirmed by cyanide inhibition. No effect of SHAM, salicylhydroxamic acid, on respiration suggests electron flow via cytochrome c oxidase. Glucose entry into spores was not detectable before 1 h after triggering germination. The impact of sorbic acid on germination was examined and we showed that it inhibits glucose uptake. O2 uptake was also inhibited, delaying the onset of respiration and extending the period of fermentation. In conclusion, we show that conidia suspended in water are not completely dormant and that conidial outgrowth involves fermentative metabolism that precedes respiration.
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Affiliation(s)
| | - Malcolm Stratford
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK; Mologic Ltd, Bedford Technology Park, Thurleigh, Bedfordshire MK44 2YA, UK.
| | - Martin J Blythe
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Raymond Wilson
- Deep Seq, Faculty of Medicine and Health Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Richard G Beniston
- Biological Mass Spectrometry Facility biOMICS, University of Sheffield, Brook Hill Road, Sheffield S3 7HF, UK.
| | - David B Archer
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
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Hagiwara D, Takahashi H, Kusuya Y, Kawamoto S, Kamei K, Gonoi T. Comparative transcriptome analysis revealing dormant conidia and germination associated genes in Aspergillus species: an essential role for AtfA in conidial dormancy. BMC Genomics 2016; 17:358. [PMID: 27185182 PMCID: PMC4869263 DOI: 10.1186/s12864-016-2689-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 05/04/2016] [Indexed: 01/22/2023] Open
Abstract
Background Fungal conidia are usually dormant unless the extracellular conditions are right for germination. Despite the importance of dormancy, little is known about the molecular mechanism underlying entry to, maintenance of, and exit from dormancy. To gain comprehensive and inter-species insights, transcriptome analyses were conducted across Aspergillus fumigatus, Aspergillus niger, and Aspergillus oryzae. Results We found transcripts of 687, 694, and 812 genes were enriched in the resting conidia compared with hyphae in A. fumigatus, A. niger, and A. oryzae, respectively (conidia-associated genes). Similarly, transcripts of 766, 1,241, and 749 genes were increased in the 1 h-cultured conidia compared with the resting conidia (germination-associated genes). Among the three Aspergillus species, we identified orthologous 6,172 genes, 91 and 391 of which are common conidia- and germination-associated genes, respectively. A variety of stress-related genes, including the catalase genes, were found in the common conidia-associated gene set, and ribosome-related genes were significantly enriched among the germination-associated genes. Among the germination-associated genes, we found that calA-family genes encoding a thaumatin-like protein were extraordinary expressed in early germination stage in all Aspergillus species tested here. In A. fumigatus 63 % of the common conidia-associated genes were expressed in a bZIP-type transcriptional regulator AtfA-dependent manner, indicating that AtfA plays a pivotal role in the maintenance of resting conidial physiology. Unexpectedly, the precocious expression of the germination-associated calA and an abnormal metabolic activity were detected in the resting conidia of the atfA mutant, suggesting that AtfA was involved in the retention of conidial dormancy. Conclusions A comparison among transcriptomes of hyphae, resting conidia, and 1 h-grown conidia in the three Aspergillus species revealed likely common factors involved in conidial dormancy. AtfA positively regulates conidial stress-related genes and negatively mediates the gene expressions related to germination, suggesting a major role for AtfA in Aspergillus conidial dormancy. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-2689-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Daisuke Hagiwara
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan.
| | - Hiroki Takahashi
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan.,Molecular Chirality Research Center, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan
| | - Yoko Kusuya
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Susumu Kawamoto
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Katsuhiko Kamei
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
| | - Tohru Gonoi
- Medical Mycology Research Center (MMRC), Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8673, Japan
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31
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Xu Q, Liu Y, Li S, Jiang L, Huang H, Wen J. Transcriptome analysis of Rhizopus oryzae in response to xylose during fumaric acid production. Bioprocess Biosyst Eng 2016; 39:1267-80. [DOI: 10.1007/s00449-016-1605-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Accepted: 04/04/2016] [Indexed: 12/20/2022]
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32
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Gerin D, De Miccolis Angelini RM, Pollastro S, Faretra F. RNA-Seq Reveals OTA-Related Gene Transcriptional Changes in Aspergillus carbonarius. PLoS One 2016; 11:e0147089. [PMID: 26765536 PMCID: PMC4713082 DOI: 10.1371/journal.pone.0147089] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 12/26/2015] [Indexed: 12/18/2022] Open
Abstract
Ochratoxin A (OTA) is a mycotoxin harmful for animals and humans. Aspergillus carbonarius is the main responsible for OTA contamination of grapes and derived products. Gene transcriptional profiling of 4 A. carbonarius strains was carried out by RNA-Seq analysis to study transcriptome changes associated with OTA production. By comparing OTA inducing (OTAI) vs. non-inducing (OTAN) cultural conditions, a total of 3,705 differentially expressed genes (DEGs) (fold change > |2| and FDR ≤ 0.05) were identified. Several genes involved in primary metabolic processes, with particular regard to carbohydrate and amino acid metabolisms, secondary metabolic processes, transport, response to stress and sporulation were up-regulated by OTAI conditions at all the analysed sampling times (4, 6 and 8 DAI) or starting from 6 DAI. Highly up-regulated DEGs encoding enzymes involved in biosynthesis of secondary metabolites, oxidoreductases, transporters and transcription factors were examined for their potential involvement in OTA biosynthesis and related metabolic pathways. Differential expression of genes encoding polyketide synthases (pks), non-ribosomal peptide synthetases (nrps) and chloroperoxidase (cpo) was validated by RT-qPCR. Among clusters of co-regulated genes involved in SM biosynthesis, one putative OTA-gene cluster, including both pks and nrps genes, was detected in the A. carbonarius genome.
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Affiliation(s)
- Donato Gerin
- Department of Soil, Plant and Food Sciences, Section of Plant Pathology, University of Bari Aldo Moro, Bari, Italy
| | - Rita M. De Miccolis Angelini
- Department of Soil, Plant and Food Sciences, Section of Plant Pathology, University of Bari Aldo Moro, Bari, Italy
| | - Stefania Pollastro
- Department of Soil, Plant and Food Sciences, Section of Plant Pathology, University of Bari Aldo Moro, Bari, Italy
| | - Francesco Faretra
- Department of Soil, Plant and Food Sciences, Section of Plant Pathology, University of Bari Aldo Moro, Bari, Italy
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33
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Mueller RC, Gallegos-Graves L, Zak DR, Kuske CR. Assembly of Active Bacterial and Fungal Communities Along a Natural Environmental Gradient. MICROBIAL ECOLOGY 2016; 71:57-67. [PMID: 26280745 DOI: 10.1007/s00248-015-0655-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 07/21/2015] [Indexed: 06/04/2023]
Abstract
Dormancy is thought to promote biodiversity within microbial communities, but how assembly of the active community responds to changes in environmental conditions is unclear. To measure the active and dormant communities of bacteria and fungi colonizing decomposing litter in maple forests, we targeted ribosomal genes and transcripts across a natural environmental gradient. Within bacterial and fungal communities, the active and dormant communities were phylogenetically distinct, but patterns of phylogenetic clustering varied. For bacteria, active communities were significantly more clustered than dormant communities, while the reverse was found for fungi. The proportion of operational taxonomic units (OTUs) classified as active and the degree of phylogenetic clustering of the active bacterial communities declined with increasing pH and decreasing C/N. No significant correlations were found for the fungal community. The opposing pattern of phylogenetic clustering in dormant and active communities and the differential response of active communities to environmental gradients suggest that dormancy differentially structures bacterial and fungal communities.
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Affiliation(s)
- Rebecca C Mueller
- Bioscience Division, M888, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
| | | | - Donald R Zak
- School of Natural Resources and Environment, Ann Arbor, MI, 48109, USA
| | - Cheryl R Kuske
- Bioscience Division, M888, Los Alamos National Laboratory, Los Alamos, NM, 87545, USA
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Han S, Liu Y, Xie L, Zhu B, Hu Y. Comparative expression profiling of genes involved in primary metabolism in high-yield and wild-type strains of Acremonium chrysogenum. Antonie van Leeuwenhoek 2015; 109:357-69. [PMID: 26708072 DOI: 10.1007/s10482-015-0638-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 12/17/2015] [Indexed: 11/26/2022]
Abstract
Cephalosporin C (CPC) productivity of Acremonium chrysogenum has been improved significantly through classical strain improvement programs. Here, we used transcription and metabolite profiling to address mechanisms underlying CPC production in a high yield (HY) strain. Transcription and metabolite profiling indicated that enzymes involved in amino acid production are higher in abundance in the HY strain. Moreover, results indicate a higher flow of precursors from the glycolysis and gluconeogenesis pathways to serine synthesis at the late stage of fermentation in the HY strain. In addition, less pyruvate would enter the TCA cycle thus favoring valine synthesis. Amino acid production would also benefit from a more active pentose phosphate pathway and γ-amino butyric acid shunt both generating NADPH. Moreover the glyoxylate pathway seems to be more active in the HY strain. These results may provide new leads for CPC strain improvement in industry.
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Affiliation(s)
- Shu Han
- Shanghai Institute of Pharmaceutical Industry, 1320 Beijing Road (W), Shanghai, 200040, China
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Yan Liu
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Liping Xie
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China
| | - Baoquan Zhu
- Shanghai Institute of Pharmaceutical Industry, 1320 Beijing Road (W), Shanghai, 200040, China
| | - Youjia Hu
- China State Institute of Pharmaceutical Industry, Zhangjiang Institute, 285 Gebaini Road, Shanghai, 201203, China.
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35
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Tsujii M, Okuda S, Ishi K, Madokoro K, Takeuchi M, Yamagata Y. A long natural-antisense RNA is accumulated in the conidia of Aspergillus oryzae. Biosci Biotechnol Biochem 2015; 80:386-98. [PMID: 26539735 DOI: 10.1080/09168451.2015.1101333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Analysis of expressed sequence tag libraries from various culture conditions revealed the existence of conidia-specific transcripts assembled to putative conidiation-specific reductase gene (csrA) in Aspergillus oryzae. However, the all transcripts were transcribed with opposite direction to the gene csrA. The sequence analysis of the transcript revealed that the RNA overlapped mRNA of csrA with 3'-end, and did not code protein longer than 60 amino acid residues. We designated the transcript Conidia Specific Long Natural-antisense RNA (CSLNR). The real-time PCR analysis demonstrated that the CSLNR is conidia-specific transcript, which cannot be transcribed in the absence of brlA, and the amount of CSLNR was much more than that of the transcript from csrA in conidia. Furthermore, the csrA deletion, also lacking coding region of CSLNR in A. oryzae reduced the number of conidia. Overexpression of CsrA demonstrated the inhibition of growth and conidiation, while CSLNR did not affect conidiation.
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Affiliation(s)
- Masaru Tsujii
- a Department of Applied Life Science , United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology , Fuchu , Japan
| | - Satoshi Okuda
- b Faculty of Agriculture, Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan
| | - Kazutomo Ishi
- c Department of Applied Biological Chemistry , Graduate School of Agriculture, Tokyo University of Agriculture and Technology , Fuchu , Japan
| | - Kana Madokoro
- c Department of Applied Biological Chemistry , Graduate School of Agriculture, Tokyo University of Agriculture and Technology , Fuchu , Japan
| | - Michio Takeuchi
- a Department of Applied Life Science , United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology , Fuchu , Japan.,b Faculty of Agriculture, Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.,c Department of Applied Biological Chemistry , Graduate School of Agriculture, Tokyo University of Agriculture and Technology , Fuchu , Japan
| | - Youhei Yamagata
- a Department of Applied Life Science , United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology , Fuchu , Japan.,b Faculty of Agriculture, Department of Applied Biological Science , Tokyo University of Agriculture and Technology , Fuchu , Japan.,c Department of Applied Biological Chemistry , Graduate School of Agriculture, Tokyo University of Agriculture and Technology , Fuchu , Japan
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Blasi B, Tafer H, Tesei D, Sterflinger K. From Glacier to Sauna: RNA-Seq of the Human Pathogen Black Fungus Exophiala dermatitidis under Varying Temperature Conditions Exhibits Common and Novel Fungal Response. PLoS One 2015; 10:e0127103. [PMID: 26061625 PMCID: PMC4463862 DOI: 10.1371/journal.pone.0127103] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 04/10/2015] [Indexed: 01/28/2023] Open
Abstract
Exophiala dermatitidis (Wangiella dermatitidis) belongs to the group of the so-called black yeasts. Thanks in part to its thick and strongly melanized cell walls, E. dermatitidis is extremely tolerant to various kinds of stress, including extreme pH, temperature and desiccation. E. dermatitidis is also the agent responsible for various severe illnesses in humans, such as pneumonia and keratitis, and might lead to fatal brain infections. Due to its association with the human environment, its poly-extremophilic lifestyle and its pathogenicity in humans, E. dermatitidis has become an important model organism. In this study we present the functional analysis of the transcriptional response of the fungus at 1°C and 45°C, in comparison with that at 37°C, for two different exposition times, i.e. 1 hour and 1 week. At 1°C, E. dermatitidis uses a large repertoire of tools to acclimatize, such as lipid membrane fluidization, trehalose production or cytoskeleton rearrangement, which allows the fungus to remain metabolically active. At 45°C, the fungus drifts into a replicative state and increases the activity of the Golgi apparatus. As a novel finding, our study provides evidence that, apart from the protein coding genes, non-coding RNAs, circular RNAs as well as fusion-transcripts are differentially regulated and that the function of the fusion-transcripts can be related to the corresponding temperature condition. This work establishes that E. dermatitidis adapts to its environment by modulating coding and non-coding gene transcription levels and through the regulation of chimeric and circular RNAs.
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Affiliation(s)
- Barbara Blasi
- VIBT-Extremophile Center, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Hakim Tafer
- VIBT-Extremophile Center, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Donatella Tesei
- VIBT-Extremophile Center, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Katja Sterflinger
- VIBT-Extremophile Center, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
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37
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Šimkovič M, Olejníková P, Mat'at'a M, Žemla P, Vilimová V, Farkašová L, Varečka L. Nutrient transport into germinating Trichoderma atroviride conidia and development of its driving force. MICROBIOLOGY-SGM 2015; 161:1240-50. [PMID: 25777081 DOI: 10.1099/mic.0.000079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The exit from dormancy and the start of growth should be preceded or at least accompanied by the uptake of nutrients. In this work we studied changes in the transport of several nutrients into Trichoderma atroviride conidia. Germination started with a short period of isodiametric growth (conidial swelling), followed by polarized growth (germ tube formation) after about 8 h at 26 °C. The onset of isodiametric growth required the presence of external both phosphate and nitrate. At the same time, an increased uptake of precursors of macromolecules and phospholipids ((14)C- or (3)H-labelled valine, uracil, N-acetylglucosamine and choline) occurred. A low uptake of these precursors was observed also in non-germinating conidia. Concomitantly, this uptake developed an increased sensitivity to the uncoupler 3,3',4',5-tetrachlorosalicylanilide. Expression and activity of H(+)-ATPase started after completing isodiametric growth, suggesting that the proton-motive force (PMF) generated by H(+)-ATPase may be an accelerator of nutrient uptake and metabolism. (14)C-valine uptake was also measured into a mutant with disrupted pma1 gene. This mutant did not form conidia. The mutant also exhibited uncoupler sensitivity of (14)C-valine uptake. These observations showed that a PMF must have been generated by a mechanism(s) other than the H(+)-ATPase activity in the WT before H(+)-ATPase expression and in mycelia with disrupted H(+)-ATPase.
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Affiliation(s)
- Martin Šimkovič
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - Petra Olejníková
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - Matej Mat'at'a
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - Peter Žemla
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - Viera Vilimová
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - Lenka Farkašová
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
| | - L'udovít Varečka
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, 81237-Bratislava, Slovakia
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Multiple Phosphatases Regulate Carbon Source-Dependent Germination and Primary Metabolism in Aspergillus nidulans. G3-GENES GENOMES GENETICS 2015; 5:857-72. [PMID: 25762568 PMCID: PMC4426372 DOI: 10.1534/g3.115.016667] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Aspergillus nidulans is an important mold and a model system for the study of fungal cell biology. In addition, invasive A. nidulans pulmonary infections are common in humans with chronic granulomatous disease. The morphological and biochemical transition from dormant conidia into active, growing, filamentous hyphae requires the coordination of numerous biosynthetic, developmental, and metabolic processes. The present study exhibited the diversity of roles performed by seven phosphatases in regulating cell cycle, development, and metabolism in response to glucose and alternative carbon sources. The identified phosphatases highlighted the importance of several signaling pathways regulating filamentous growth, the action of the pyruvate dehydrogenase complex as a metabolic switch controlling carbon usage, and the identification of the key function performed by the α-ketoglutarate dehydrogenase during germination. These novel insights into the fundamental roles of numerous phosphatases in germination and carbon sensing have provided new avenues of research into the identification of inhibitors of fungal germination, with implications for the food, feed, and pharmaceutical industries.
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Llanos A, François JM, Parrou JL. Tracking the best reference genes for RT-qPCR data normalization in filamentous fungi. BMC Genomics 2015; 16:71. [PMID: 25757610 PMCID: PMC4342825 DOI: 10.1186/s12864-015-1224-y] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 01/07/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND A critical step in the RT-qPCR workflow for studying gene expression is data normalization, one of the strategies being the use of reference genes. This study aimed to identify and validate a selection of reference genes for relative quantification in Talaromyces versatilis, a relevant industrial filamentous fungus. Beyond T. versatilis, this study also aimed to propose reference genes that are applicable more widely for RT-qPCR data normalization in filamentous fungi. RESULTS A selection of stable, potential reference genes was carried out in silico from RNA-seq based transcriptomic data obtained from T. versatilis. A dozen functionally unrelated candidate genes were analysed by RT-qPCR assays over more than 30 relevant culture conditions. By using geNorm, we showed that most of these candidate genes had stable transcript levels in most of the conditions, from growth environments to conidial germination. The overall robustness of these genes was explored further by showing that any combination of 3 of them led to minimal normalization bias. To extend the relevance of the study beyond T. versatilis, we challenged their stability together with sixteen other classically used genes such as β-tubulin or actin, in a representative sample of about 100 RNA-seq datasets. These datasets were obtained from 18 phylogenetically distant filamentous fungi exposed to prevalent experimental conditions. Although this wide analysis demonstrated that each of the chosen genes exhibited sporadic up- or down-regulation, their hierarchical clustering allowed the identification of a promising group of 6 genes, which presented weak expression changes and no tendency to up- or down-regulation over the whole set of conditions. This group included ubcB, sac7, fis1 and sarA genes, as well as TFC1 and UBC6 that were previously validated for their use in S. cerevisiae. CONCLUSIONS We propose a set of 6 genes that can be used as reference genes in RT-qPCR data normalization in any field of fungal biology. However, we recommend that the uniform transcription of these genes is tested by systematic experimental validation and to use the geometric averaging of at least 3 of the best ones. This will minimize the bias in normalization and will support trustworthy biological conclusions.
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Affiliation(s)
- Agustina Llanos
- Université de Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077, Toulouse, France. .,INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400, Toulouse, France. .,CNRS, UMR5504, F-31400, Toulouse, France. .,Cinabio-Adisseo France S.A.S., 135 Avenue de Rangueil, 31077, Toulouse, France.
| | - Jean Marie François
- Université de Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077, Toulouse, France. .,INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400, Toulouse, France. .,CNRS, UMR5504, F-31400, Toulouse, France.
| | - Jean-Luc Parrou
- Université de Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077, Toulouse, France. .,INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400, Toulouse, France. .,CNRS, UMR5504, F-31400, Toulouse, France.
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Linde J, Duggan S, Weber M, Horn F, Sieber P, Hellwig D, Riege K, Marz M, Martin R, Guthke R, Kurzai O. Defining the transcriptomic landscape of Candida glabrata by RNA-Seq. Nucleic Acids Res 2015; 43:1392-406. [PMID: 25586221 PMCID: PMC4330350 DOI: 10.1093/nar/gku1357] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Candida glabrata is the second most common pathogenic Candida species and has emerged as a leading cause of nosocomial fungal infections. Its reduced susceptibility to antifungal drugs and its close relationship to Saccharomyces cerevisiae make it an interesting research focus. Although its genome sequence was published in 2004, little is known about its transcriptional dynamics. Here, we provide a detailed RNA-Seq-based analysis of the transcriptomic landscape of C. glabrata in nutrient-rich media, as well as under nitrosative stress and during pH shift. Using RNA-Seq data together with state-of-the-art gene prediction tools, we refined the annotation of the C. glabrata genome and predicted 49 novel protein-coding genes. Of these novel genes, 14 have homologs in S. cerevisiae and six are shared with other Candida species. We experimentally validated four novel protein-coding genes of which two are differentially regulated during pH shift and interaction with human neutrophils, indicating a potential role in host–pathogen interaction. Furthermore, we identified 58 novel non-protein-coding genes, 38 new introns and condition-specific alternative splicing. Finally, our data suggest different patterns of adaptation to pH shift and nitrosative stress in C. glabrata, Candida albicans and S. cerevisiae and thus further underline a distinct evolution of virulence in yeast.
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Affiliation(s)
- Jörg Linde
- Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Seána Duggan
- Septomics Research Center, Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Michael Weber
- Septomics Research Center, Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Fabian Horn
- Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Patricia Sieber
- Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany Department of Bioinformatics, Faculty of Biology and Pharmacy, Friedrich Schiller University, Jena, Germany
| | - Daniela Hellwig
- Septomics Research Center, Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Konstantin Riege
- Research Group Bioinformatics and High Throughput Analysis, Faculty of Mathematics and Computer Sciences, Friedrich Schiller University, Jena, Germany
| | - Manja Marz
- Research Group Bioinformatics and High Throughput Analysis, Faculty of Mathematics and Computer Sciences, Friedrich Schiller University, Jena, Germany
| | - Ronny Martin
- Septomics Research Center, Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Reinhard Guthke
- Research Group Systems Biology and Bioinformatics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
| | - Oliver Kurzai
- Septomics Research Center, Fungal Septomics, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany National Reference Center for Invasive Mycoses, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knoell Institute, Jena, Germany
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Meyer V, Fiedler M, Nitsche B, King R. The Cell Factory Aspergillus Enters the Big Data Era: Opportunities and Challenges for Optimising Product Formation. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 149:91-132. [PMID: 25616499 DOI: 10.1007/10_2014_297] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Living with limits. Getting more from less. Producing commodities and high-value products from renewable resources including waste. What is the driving force and quintessence of bioeconomy outlines the lifestyle and product portfolio of Aspergillus, a saprophytic genus, to which some of the top-performing microbial cell factories belong: Aspergillus niger, Aspergillus oryzae and Aspergillus terreus. What makes them so interesting for exploitation in biotechnology and how can they help us to address key challenges of the twenty-first century? How can these strains become trimmed for better growth on second-generation feedstocks and how can we enlarge their product portfolio by genetic and metabolic engineering to get more from less? On the other hand, what makes it so challenging to deduce biological meaning from the wealth of Aspergillus -omics data? And which hurdles hinder us to model and engineer industrial strains for higher productivity and better rheological performance under industrial cultivation conditions? In this review, we will address these issues by highlighting most recent findings from the Aspergillus research with a focus on fungal growth, physiology, morphology and product formation. Indeed, the last years brought us many surprising insights into model and industrial strains. They clearly told us that similar is not the same: there are different ways to make a hypha, there are more protein secretion routes than anticipated and there are different molecular and physical mechanisms which control polar growth and the development of hyphal networks. We will discuss new conceptual frameworks derived from these insights and the future scientific advances necessary to create value from Aspergillus Big Data.
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Affiliation(s)
- Vera Meyer
- Department Applied and Molecular Microbiology, Institute of Biotechnology, Berlin University of Technology, Gustav-Meyer-Allee 25, 13355, Berlin, Germany,
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Zhang F, Guo Z, Zhong H, Wang S, Yang W, Liu Y, Wang S. RNA-Seq-based transcriptome analysis of aflatoxigenic Aspergillus flavus in response to water activity. Toxins (Basel) 2014; 6:3187-207. [PMID: 25421810 PMCID: PMC4247253 DOI: 10.3390/toxins6113187] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 10/27/2014] [Accepted: 11/13/2014] [Indexed: 01/06/2023] Open
Abstract
Aspergillus flavus is one of the most important producers of carcinogenic aflatoxins in crops, and the effect of water activity (aw) on growth and aflatoxin production of A. flavus has been previously studied. Here we found the strains under 0.93 aw exhibited decreased conidiation and aflatoxin biosynthesis compared to that under 0.99 aw. When RNA-Seq was used to delineate gene expression profile under different water activities, 23,320 non-redundant unigenes, with an average length of 1297 bp, were yielded. By database comparisons, 19,838 unigenes were matched well (e-value < 10−5) with known gene sequences, and another 6767 novel unigenes were obtained by comparison to the current genome annotation of A. flavus. Based on the RPKM equation, 5362 differentially expressed unigenes (with |log2Ratio| ≥ 1) were identified between 0.99 aw and 0.93 aw treatments, including 3156 up-regulated and 2206 down-regulated unigenes, suggesting that A. flavus underwent an extensive transcriptome response during water activity variation. Furthermore, we found that the expression of 16 aflatoxin producing-related genes decreased obviously when water activity decreased, and the expression of 11 development-related genes increased after 0.99 aw treatment. Our data corroborate a model where water activity affects aflatoxin biosynthesis through increasing the expression of aflatoxin producing-related genes and regulating development-related genes.
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Affiliation(s)
- Feng Zhang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zhenni Guo
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Hong Zhong
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Sen Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Weiqiang Yang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Yongfeng Liu
- Shenzhen Key Laboratory of Bioenergy, BGI-Shenzhen, Shenzhen 518083, China.
| | - Shihua Wang
- Key Laboratory of Pathogenic Fungi and Mycotoxins of Fujian Province, Key Laboratory of Biopesticide and Chemical Biology of the Education Ministry, and School of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Liaud N, Giniés C, Navarro D, Fabre N, Crapart S, Gimbert IH, Levasseur A, Raouche S, Sigoillot JC. RNA-sequencing reveals the complexities of the transcriptional response to lignocellulosic biofuel substrates in Aspergillus niger. Fungal Biol Biotechnol 2014; 1:1-14. [PMID: 26457194 PMCID: PMC4599204 DOI: 10.1186/s40694-014-0003-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/23/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Saprobic fungi are the predominant industrial sources of Carbohydrate Active enZymes (CAZymes) used for the saccharification of lignocellulose during the production of second generation biofuels. The production of more effective enzyme cocktails is a key objective for efficient biofuel production. To achieve this objective, it is crucial to understand the response of fungi to lignocellulose substrates. Our previous study used RNA-seq to identify the genes induced in Aspergillus niger in response to wheat straw, a biofuel feedstock, and showed that the range of genes induced was greater than previously seen with simple inducers. RESULTS In this work we used RNA-seq to identify the genes induced in A. niger in response to short rotation coppice willow and compared this with the response to wheat straw from our previous study, at the same time-point. The response to willow showed a large increase in expression of genes encoding CAZymes. Genes encoding the major activities required to saccharify lignocellulose were induced on willow such as endoglucanases, cellobiohydrolases and xylanases. The transcriptome response to willow had many similarities with the response to straw with some significant differences in the expression levels of individual genes which are discussed in relation to differences in substrate composition or other factors. Differences in transcript levels include higher levels on wheat straw from genes encoding enzymes classified as members of GH62 (an arabinofuranosidase) and CE1 (a feruloyl esterase) CAZy families whereas two genes encoding endoglucanases classified as members of the GH5 family had higher transcript levels when exposed to willow. There were changes in the cocktail of enzymes secreted by A. niger when cultured with willow or straw. Assays for particular enzymes as well as saccharification assays were used to compare the enzyme activities of the cocktails. Wheat straw induced an enzyme cocktail that saccharified wheat straw to a greater extent than willow. Genes not encoding CAZymes were also induced on willow such as hydrophobins as well as genes of unknown function. Several genes were identified as promising targets for future study. CONCLUSIONS By comparing this first study of the global transcriptional response of a fungus to willow with the response to straw, we have shown that the inducing lignocellulosic substrate has a marked effect upon the range of transcripts and enzymes expressed by A. niger. The use by industry of complex substrates such as wheat straw or willow could benefit efficient biofuel production.
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Affiliation(s)
- Nadège Liaud
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Christian Giniés
- INRA, UMR 1260, « Nutrition, Obésité et Risque Thrombotique », Marseille, F-13385 France
- INSERM, UMR 1062, « Nutrition, Obésité et Risque Thrombotique », Marseille, F-13385 France
- Université d’Aix-Marseille, UMR 1260, « Nutrition, Obésité et Risque Thrombotique », Faculté de Médecine, Marseille, F-13385 France
| | - David Navarro
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- INRA, International Center for Microbial Resources collection-Filamentous fungi CIRM-CF, Marseille, F-13288 France
| | - Nicolas Fabre
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Sylvaine Crapart
- ARD, Agro-Industry Research and Development, Pômacle, F-51100 France
| | - Isabelle Herpoël- Gimbert
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
| | - Anthony Levasseur
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
| | - Sana Raouche
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Polytech’ Marseille (ex ESIL), UMR 1163 BCF - INRA / AMU, 163 Avenue de Luminy CP 925, Marseille, F-13288 France
| | - Jean-Claude Sigoillot
- INRA, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
- Aix Marseille Université, UMR1163 Biotechnology of Filamentous Fungi, Marseille, F-13288 France
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Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids. Appl Environ Microbiol 2014; 80:6046-53. [PMID: 25063657 DOI: 10.1128/aem.01078-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore.
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Kaliňák M, Simkovič M, Zemla P, Matata M, Molnár T, Liptaj T, Varečka L, Hudecová D. Changes in metabolome and in enzyme activities during germination of Trichoderma atroviride conidia. FEMS Microbiol Lett 2014; 357:201-7. [PMID: 24964818 DOI: 10.1111/1574-6968.12516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 05/27/2014] [Accepted: 06/17/2014] [Indexed: 11/29/2022] Open
Abstract
The aim of this work was to study the metabolic changes during germination of Trichoderma atroviride conidia along with selected marker enzyme activities. The increase in proteinogenic amino acid concentrations together with the increase in glutamate dehydrogenase activity suggests a requirement for nitrogen metabolism. Even though the activities of tricarboxylic acid cycle enzymes also increased, detected organic acid pools did not change, which predisposes this pathway to energy production and supply of intermediates for further metabolism. The concentrations of many metabolites, including the main osmolytes mannitol and betaine, also increased during the formation of germ tubes. The activities of H(+)-ATPase and GDPase, the only marker enzymes that did not have detectable activity in non-germinated conidia, were shown with germ tubes.
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Affiliation(s)
- Michal Kaliňák
- Department of Biochemistry and Microbiology, Faculty of Chemical and Food Technology, Slovak University of Technology, Bratislava, Slovakia
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Svanström Å, van Leeuwen MR, Dijksterhuis J, Melin P. Trehalose synthesis in Aspergillus niger: characterization of six homologous genes, all with conserved orthologs in related species. BMC Microbiol 2014; 14:90. [PMID: 24725382 PMCID: PMC3991884 DOI: 10.1186/1471-2180-14-90] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/08/2014] [Indexed: 11/12/2022] Open
Abstract
Background The disaccharide trehalose is a major component of fungal spores and is released upon germination. Moreover, the sugar is well known for is protective functions, e.g. against thermal stress and dehydration. The properties and synthesis of trehalose have been well investigated in the bakers’ yeast Saccharomyces cerevisiae. In filamentous fungi, such knowledge is limited, although several gene products have been identified. Results Using Aspergillus niger as a model fungus, the aim of this study was to provide an overview of all genes involved in trehalose synthesis. This fungus has three potential trehalose-6-phosphate synthase encoding genes, tpsA-C, and three putative trehalose phosphate phosphatase encoding genes, tppA-C, of which two have not previously been identified. Expression of all six genes was confirmed using real-time PCR, and conserved orthologs could be identified in related Aspergilli. Using a two-hybrid approach, there is a strong indication that four of the proteins physically interact, as has previously been shown in S. cerevisiae. When creating null mutants of all the six genes, three of them, ΔtpsA, ΔtppA and ΔtppB, had lower internal trehalose contents. The only mutant with a pronounced morphological difference was ΔtppA, in which sporulation was severely reduced with abnormal conidiophores. This was also the only mutant with accumulated levels of trehalose-6-phosphate, indicating that the encoded protein is the main phosphatase under normal conditions. Besides ΔtppA, the most studied deletion mutant in this work was ΔtppB. This gene encodes a protein conserved in filamentous Ascomycota. The ΔtppB mutant displayed a low, but not depleted, internal trehalose content, and conidia were more susceptible to thermal stress. Conclusion A. niger contains at least 6 genes putatively involved in trehalose synthesis. Gene expressions related to germination have been quantified and deletion mutants characterized: Mutants lacking tpsA, tppA or tppB have reduced internal trehalose contents. Furthermore, tppA, under normal conditions, encodes the functional trehalose-6-phosphate-phosphatase.
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Affiliation(s)
| | | | | | - Petter Melin
- Uppsala BioCenter, Department of Microbiology, Swedish University of Agricultural Sciences, P,O, Box 7025, SE-750 07 Uppsala, Sweden.
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Sibthorp C, Wu H, Cowley G, Wong PWH, Palaima P, Morozov IY, Weedall GD, Caddick MX. Transcriptome analysis of the filamentous fungus Aspergillus nidulans directed to the global identification of promoters. BMC Genomics 2013; 14:847. [PMID: 24299161 PMCID: PMC4046813 DOI: 10.1186/1471-2164-14-847] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 11/15/2013] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The filamentous fungus Aspergillus nidulans has been a tractable model organism for cell biology and genetics for over 60 years. It is among a large number of Aspergilli whose genomes have been sequenced since 2005, including medically and industrially important species. In order to advance our knowledge of its biology and increase its utility as a genetic model by improving gene annotation we sequenced the transcriptome of A. nidulans with a focus on 5' end analysis. RESULTS Strand-specific whole transcriptome sequencing showed that 80-95% of annotated genes appear to be expressed across the conditions tested. We estimate that the total gene number should be increased by approximately 1000, to 11,800. With respect to splicing 8.3% of genes had multiple alternative transcripts, but alternative splicing by exon-skipping was very rare. 75% of annotated genes showed some level of antisense transcription and for one gene, meaB, we demonstrated the antisense transcript has a regulatory role. Specific sequencing of the 5' ends of transcripts was used for genome wide mapping of transcription start sites, allowing us to interrogate over 7000 promoters and 5' untranslated regions. CONCLUSIONS Our data has revealed the complexity of the A. nidulans transcriptome and contributed to improved genome annotation. The data can be viewed on the AspGD genome browser.
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Affiliation(s)
- Christopher Sibthorp
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Huihai Wu
- />Department of Computer Science, University of Liverpool, Ashton Building, Ashton Street, Liverpool, L69 3BX UK
| | - Gwendolyn Cowley
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Prudence W H Wong
- />Department of Computer Science, University of Liverpool, Ashton Building, Ashton Street, Liverpool, L69 3BX UK
| | - Paulius Palaima
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Igor Y Morozov
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
- />Department of Biomolecular and Sports Sciences, Faculty of Health and Life Sciences, Coventry University, James Starley Building, Coventry, CV1 5FB UK
| | - Gareth D Weedall
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
| | - Mark X Caddick
- />Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB UK
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Structural features of sugars that trigger or support conidial germination in the filamentous fungus Aspergillus niger. Appl Environ Microbiol 2013; 79:6924-31. [PMID: 23995938 DOI: 10.1128/aem.02061-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The asexual spores (conidia) of Aspergillus niger germinate to produce hyphae under appropriate conditions. Germination is initiated by conidial swelling and mobilization of internal carbon and energy stores, followed by polarization and emergence of a hyphal germ tube. The effects of different pyranose sugars, all analogues of d-glucose, on the germination of A. niger conidia were explored, and we define germination as the transition from a dormant conidium into a germling. Within germination, we distinguish two distinct stages, the initial swelling of the conidium and subsequent polarized growth. The stage of conidial swelling requires a germination trigger, which we define as a compound that is sensed by the conidium and which leads to catabolism of d-trehalose and isotropic growth. Sugars that triggered germination and outgrowth included d-glucose, d-mannose, and d-xylose. Sugars that triggered germination but did not support subsequent outgrowth included d-tagatose, d-lyxose, and 2-deoxy-d-glucose. Nontriggering sugars included d-galactose, l-glucose, and d-arabinose. Certain nontriggering sugars, including d-galactose, supported outgrowth if added in the presence of a complementary triggering sugar. This division of functions indicates that sugars are involved in two separate events in germination, triggering and subsequent outgrowth, and the structural features of sugars that support each, both, or none of these events are discussed. We also present data on the uptake of sugars during the germination process and discuss possible mechanisms of triggering in the absence of apparent sugar uptake during the initial swelling of conidia.
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