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Caballero P, Yap A, Bromley MJ, Haas H. The Transcription Factors AcuK and AcuM Influence Siderophore Biosynthesis of Aspergillus fumigatus. J Fungi (Basel) 2024; 10:327. [PMID: 38786682 PMCID: PMC11121910 DOI: 10.3390/jof10050327] [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: 03/18/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024] Open
Abstract
The mold Aspergillus fumigatus employs two high-affinity uptake systems, reductive iron assimilation (RIA) and siderophore-mediated iron acquisition (SIA), for the acquisition of the essential trace element iron. SIA has previously been shown to be crucial for virulence in mammalian hosts. Here, we show that a lack of AcuK or AcuM, transcription factors required for the activation of gluconeogenesis, decreases the production of both extra- and intracellular siderophores in A. fumigatus. The lack of AcuM or AcuK did not affect the expression of genes involved in RIA and SIA, suggesting that these regulators do not directly regulate iron homeostasis genes, but indirectly affect siderophore production through their influence on metabolism. Consistent with this, acetate supplementation reversed the intracellular siderophore production defect of ΔacuM and ΔacuK. Moreover, ΔacuM and ΔacuK displayed a similar growth defect under iron limitation and iron sufficiency, which suggests they have a general role in carbon metabolism apart from gluconeogenesis. In agreement with a potential role of the glyoxylate cycle in adaptation to iron starvation, transcript levels of the malate synthase-encoding acuE were found to be upregulated by iron limitation that is partially dependent on AcuK and AcuM. Together, these data demonstrate the influence of iron availability on carbon metabolism.
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Affiliation(s)
- Patricia Caballero
- Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria; (P.C.); (A.Y.)
| | - Annie Yap
- Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria; (P.C.); (A.Y.)
| | - Michael J. Bromley
- Manchester Fungal Infection Group, Division of Infection, Immunity, and Respiratory Medicine, The University of Manchester, Manchester M13 9PL, UK;
| | - Hubertus Haas
- Institute of Molecular Biology, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria; (P.C.); (A.Y.)
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French KS, Chukwuma E, Linshitz I, Namba K, Duckworth OW, Cubeta MA, Baars O. Inactivation of siderophore iron-chelating moieties by the fungal wheat root symbiont Pyrenophora biseptata. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13234. [PMID: 38240404 PMCID: PMC10866069 DOI: 10.1111/1758-2229.13234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 12/28/2023] [Indexed: 02/15/2024]
Abstract
We investigated the ability of four plant and soil-associated fungi to modify or degrade siderophore structures leading to reduced siderophore iron-affinity in iron-limited and iron-replete cultures. Pyrenophora biseptata, a melanized fungus from wheat roots, was effective in inactivating siderophore iron-chelating moieties. In the supernatant solution, the tris-hydroxamate siderophore desferrioxamine B (DFOB) underwent a stepwise reduction of the three hydroxamate groups in DFOB to amides leading to a progressive loss in iron affinity. A mechanism is suggested based on the formation of transient ferrous iron followed by reduction of the siderophore hydroxamate groups during fungal high-affinity reductive iron uptake. P. biseptata also produced its own tris-hydroxamate siderophores (neocoprogen I and II, coprogen and dimerum acid) in iron-limited media and we observed loss of hydroxamate chelating groups during incubation in a manner analogous to DFOB. A redox-based reaction was also involved with the tris-catecholate siderophore protochelin in which oxidation of the catechol groups to quinones was observed. The new siderophore inactivating activity of the wheat symbiont P. biseptata is potentially widespread among fungi with implications for the availability of iron to plants and the surrounding microbiome in siderophore-rich environments.
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Affiliation(s)
- Katie S. French
- Department of Entomology and Plant PathologyNorth Carolina State University, Center for Integrated Fungal ResearchRaleighNorth CarolinaUSA
- Present address:
Department of Soil ScienceUniversity of ArkansasFayettevilleArkansasUSA
| | - Emmanuel Chukwuma
- Department of ChemistryNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Ilan Linshitz
- Department of BiologyUniversity of MarylandCollege ParkMarylandUSA
| | - Kosuke Namba
- Department of Pharmaceutical SciencesTokushima UniversityTokushimaJapan
| | - Owen W. Duckworth
- Department of Crop and Soil SciencesNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Marc A. Cubeta
- Department of Entomology and Plant PathologyNorth Carolina State University, Center for Integrated Fungal ResearchRaleighNorth CarolinaUSA
| | - Oliver Baars
- Department of Entomology and Plant PathologyNorth Carolina State University, Center for Integrated Fungal ResearchRaleighNorth CarolinaUSA
- Department of ChemistryNorth Carolina State UniversityRaleighNorth CarolinaUSA
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3
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Happacher I, Aguiar M, Yap A, Decristoforo C, Haas H. Fungal siderophore metabolism with a focus on Aspergillus fumigatus: impact on biotic interactions and potential translational applications. Essays Biochem 2023; 67:829-842. [PMID: 37313590 PMCID: PMC10500206 DOI: 10.1042/ebc20220252] [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: 04/03/2023] [Revised: 05/22/2023] [Accepted: 05/26/2023] [Indexed: 06/15/2023]
Abstract
Iron is an essential trace element that is limiting in most habitats including hosts for fungal pathogens. Siderophores are iron-chelators synthesized by most fungal species for high-affinity uptake and intracellular handling of iron. Moreover, virtually all fungal species including those lacking siderophore biosynthesis appear to be able to utilize siderophores produced by other species. Siderophore biosynthesis has been shown to be crucial for virulence of several fungal pathogens infecting animals and plants revealing induction of this iron acquisition system during virulence, which offers translational potential of this fungal-specific system. The present article summarizes the current knowledge on the fungal siderophore system with a focus on Aspergillus fumigatus and its potential translational application including noninvasive diagnosis of fungal infections via urine samples, imaging of fungal infections via labeling of siderophores with radionuclides such as Gallium-68 for detection with positron emission tomography, conjugation of siderophores with fluorescent probes, and development of novel antifungal strategies.
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Affiliation(s)
- Isidor Happacher
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Mario Aguiar
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Annie Yap
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, Innsbruck, Austria
| | - Hubertus Haas
- Institute of Molecular Biology, Biocenter, Medical University of Innsbruck, 6020 Innsbruck, Austria
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Ye J, Wang Y, Li X, Wan Q, Zhang Y, Lu L. Synergistic Antifungal Effect of a Combination of Iron Deficiency and Calcium Supplementation. Microbiol Spectr 2022; 10:e0112122. [PMID: 35674440 PMCID: PMC9241635 DOI: 10.1128/spectrum.01121-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/19/2022] [Indexed: 01/10/2023] Open
Abstract
Fungal diseases have become a major public health issue worldwide. Increasing drug resistance and the limited number of available antifungals result in high morbidity and mortality. Metal-based drugs have been reported to be therapeutic agents against major protozoan diseases, but knowledge of their ability to function as antifungals is limited. In this study, we found that calcium supplementation combined with iron deficiency causes dramatic growth inhibition of the human fungal pathogens Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. Calcium induces the downregulation of iron uptake-related genes and, in particular, causes a decrease in the expression of the transcription factor HapX, which tends to transcriptionally activate siderophore-mediated iron acquisition under iron-deficient conditions. Iron deficiency causes calcium overload and the overproduction of intracellular reactive oxygen species (ROS), and perturbed ion homeostasis suppresses fungal growth. These phenomena are consistently identified in azole-resistant A. fumigatus isolates. The findings here imply that low iron availability lets cells mistakenly absorb calcium as a substitute, causing calcium abnormalities. Thus, there is a mutual effect between iron and calcium in fungal pathogens, and the combination of calcium with an iron chelator could serve to improve antifungal therapy. IMPORTANCE Millions of immunocompromised people are at a higher risk of developing different types of severe fungal diseases. The limited number of antifungals and the emergence of antimicrobial resistance highlight an urgent need for new strategies against invasive fungal infections. Here, we report that calcium can interfere with iron absorption of fungal pathogens, especially in iron-limited environments. Thus, a combination of calcium supplementation with an iron chelator inhibits the growth of human fungal pathogens, including Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. Moreover, we demonstrate that iron deficiency induces a nonspecific calcium uptake response, which results in toxic levels of metal. Findings in this study suggest that a microenvironment with excess calcium and limited iron is an efficient strategy to curb the growth of fungal pathogens, especially for drug-resistant isolates.
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Affiliation(s)
- Jing Ye
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yamei Wang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xinyu Li
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qinyi Wan
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Yuanwei Zhang
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ling Lu
- Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Centre for Microbiology, College of Life Sciences, Nanjing Normal University, Nanjing, China
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Ganesh Kumar A, Manisha D, Sujitha K, Magesh Peter D, Kirubagaran R, Dharani G. Genome sequence analysis of deep sea Aspergillus sydowii BOBA1 and effect of high pressure on biodegradation of spent engine oil. Sci Rep 2021; 11:9347. [PMID: 33931710 PMCID: PMC8087790 DOI: 10.1038/s41598-021-88525-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 03/30/2021] [Indexed: 02/02/2023] Open
Abstract
A deep-sea fungus Aspergillus sydowii BOBA1 isolated from marine sediment at a depth of 3000 m was capable of degrading spent engine (SE) oil. The response of immobilized fungi towards degradation at elevated pressure was studied in customized high pressure reactors without any deviation in simulating in situ deep-sea conditions. The growth rate of A. sydowii BOBA1 in 0.1 MPa was significantly different from the growth at 10 MPa pressure. The degradation percentage reached 71.2 and 82.5% at atmospheric and high pressure conditions, respectively, within a retention period of 21 days. The complete genome sequence of BOBA1 consists of 38,795,664 bp in size, comprises 2582 scaffolds with predicted total coding genes of 18,932. A total of 16,247 genes were assigned with known functions and many families found to have a potential role in PAHs and xenobiotic compound metabolism. Functional genes controlling the pathways of hydrocarbon and xenobiotics compound degrading enzymes such as dioxygenase, decarboxylase, hydrolase, reductase and peroxidase were identified. The spectroscopic and genomic analysis revealed the presence of combined catechol, gentisate and phthalic acid degradation pathway. These results of degradation and genomic studies evidenced that this deep-sea fungus could be employed to develop an eco-friendly mycoremediation technology to combat the oil polluted marine environment. This study expands our knowledge on piezophilic fungi and offer insight into possibilities about the fate of SE oil in deep-sea.
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Affiliation(s)
- A. Ganesh Kumar
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
| | - D. Manisha
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
| | - K. Sujitha
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
| | - D. Magesh Peter
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
| | - R. Kirubagaran
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
| | - G. Dharani
- grid.454780.a0000 0001 0683 2228Marine Biotechnology Division, National Institute of Ocean Technology, Ministry of Earth Sciences (MoES), Government of India, Chennai, 600100 Tamil Nadu India
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Oh J, Kang D, Hong S, Kim SH, Choi JH, Seo J. Formation of a tris(catecholato) iron(III) complex with a nature-inspired cyclic peptoid ligand. Dalton Trans 2021; 50:3459-3463. [PMID: 33599663 DOI: 10.1039/d1dt00091h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Siderophore-mimicking macrocyclic peptoids were synthesized. Peptoid 3 with intramolecular hydrogen bonds showed an optimally arranged primary coordination sphere leading to a stable catecholate-iron complex. The tris(catecholato) structure of 3-Fe(iii) was determined with UV-vis, fluorescence, and EPR spectroscopies and DFT calculations. The iron binding affinity was comparable to that of deferoxamine, with enhanced stability upon air exposure.
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Affiliation(s)
- Jinyoung Oh
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
| | - Dahyun Kang
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
| | - Sugyeong Hong
- Western Seoul Center, Korea Basic Science Institute, University-Industry Cooperation Building, 150 Bukahyun-ro, Seodaemun-gu, Seoul, 120-140, Republic of Korea
| | - Sun H Kim
- Western Seoul Center, Korea Basic Science Institute, University-Industry Cooperation Building, 150 Bukahyun-ro, Seodaemun-gu, Seoul, 120-140, Republic of Korea
| | - Jun-Ho Choi
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
| | - Jiwon Seo
- Department of Chemistry, School of Physics and Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju, 61005, Republic of Korea.
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Contrasting Role of Fungal Siderophore in Metal Ion Complex Formation. Fungal Biol 2021. [DOI: 10.1007/978-3-030-53077-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Misslinger M, Hortschansky P, Brakhage AA, Haas H. Fungal iron homeostasis with a focus on Aspergillus fumigatus. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118885. [PMID: 33045305 DOI: 10.1016/j.bbamcr.2020.118885] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/15/2020] [Accepted: 10/01/2020] [Indexed: 02/08/2023]
Abstract
To maintain iron homeostasis, fungi have to balance iron acquisition, storage, and utilization to ensure sufficient supply and to avoid toxic excess of this essential trace element. As pathogens usually encounter iron limitation in the host niche, this metal plays a particular role during virulence. Siderophores are iron-chelators synthesized by most, but not all fungal species to sequester iron extra- and intracellularly. In recent years, the facultative human pathogen Aspergillus fumigatus has become a model for fungal iron homeostasis of siderophore-producing fungal species. This article summarizes the knowledge on fungal iron homeostasis and its links to virulence with a focus on A. fumigatus. It covers mechanisms for iron acquisition, storage, and detoxification, as well as the modes of transcriptional iron regulation and iron sensing in A. fumigatus in comparison to other fungal species. Moreover, potential translational applications of the peculiarities of fungal iron metabolism for treatment and diagnosis of fungal infections is addressed.
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Affiliation(s)
- Matthias Misslinger
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter Hortschansky
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Axel A Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany; Department Microbiology and Molecular Biology, Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Hubertus Haas
- Institute of Molecular Biology - Biocenter, Medical University of Innsbruck, Innsbruck, Austria.
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Petrik M, Pfister J, Misslinger M, Decristoforo C, Haas H. Siderophore-Based Molecular Imaging of Fungal and Bacterial Infections-Current Status and Future Perspectives. J Fungi (Basel) 2020; 6:E73. [PMID: 32485852 PMCID: PMC7345832 DOI: 10.3390/jof6020073] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 12/15/2022] Open
Abstract
Invasive fungal infections such as aspergillosis are life-threatening diseases mainly affecting immuno-compromised patients. The diagnosis of fungal infections is difficult, lacking specificity and sensitivity. This review covers findings on the preclinical use of siderophores for the molecular imaging of infections. Siderophores are low molecular mass chelators produced by bacteria and fungi to scavenge the essential metal iron. Replacing iron in siderophores by radionuclides such as gallium-68 allowed the targeted imaging of infection by positron emission tomography (PET). The proof of principle was the imaging of pulmonary Aspergillus fumigatus infection using [68Ga]Ga-triacetylfusarinine C. Recently, this approach was expanded to imaging of bacterial infections, i.e., with Pseudomonas aeruginosa. Moreover, the conjugation of siderophores and fluorescent dyes enabled the generation of hybrid imaging compounds, allowing the combination of PET and optical imaging. Nevertheless, the high potential of these imaging probes still awaits translation into clinics.
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Affiliation(s)
- Milos Petrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 77900 Olomouc, Czech Republic;
| | - Joachim Pfister
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Matthias Misslinger
- Institute of Molecular Biology, Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Clemens Decristoforo
- Department of Nuclear Medicine, Medical University Innsbruck, 6020 Innsbruck, Austria;
| | - Hubertus Haas
- Institute of Molecular Biology, Medical University Innsbruck, 6020 Innsbruck, Austria;
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Alternaria alternata uses two siderophore systems for iron acquisition. Sci Rep 2020; 10:3587. [PMID: 32107432 PMCID: PMC7046739 DOI: 10.1038/s41598-020-60468-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 02/10/2020] [Indexed: 01/21/2023] Open
Abstract
Iron is one of the most abundant elements on earth and essential for life. However, Fe3+ ions are rather insoluble and microorganisms such as fungi may use siderophores as strong chelators for uptake. In addition, free cytoplasmic iron is rather toxic and intracellular siderophores are used to control the toxicity. Siderophores are also important for iron storage. We studied two siderophore systems in the plant necrotrophic fungus Alternaria alternata and show that the non-ribosomal peptide synthase, Nps2, is required for the biosynthesis of intracellular ferricrocin, whereas Nps6 is needed for the formation of extracellular coprogen and coprogen B. Whereas nps2 was dispensable for growth on iron-depleted medium, nps6 was essential under those conditions. nps2 deletion caused an increase in spore formation and reduced pathogenicity on tomato. Our results suggest that A. alternata employs an external and an internal siderophore system to adapt to low iron conditions.
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