1
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Li GB, Liu J, He JX, Li GM, Zhao YD, Liu XL, Hu XH, Zhang X, Wu JL, Shen S, Liu XX, Zhu Y, He F, Gao H, Wang H, Zhao JH, Li Y, Huang F, Huang YY, Zhao ZX, Zhang JW, Zhou SX, Ji YP, Pu M, He M, Chen X, Wang J, Li W, Wu XJ, Ning Y, Sun W, Xu ZJ, Wang WM, Fan J. Rice false smut virulence protein subverts host chitin perception and signaling at lemma and palea for floral infection. THE PLANT CELL 2024; 36:2000-2020. [PMID: 38299379 PMCID: PMC11062437 DOI: 10.1093/plcell/koae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 02/02/2024]
Abstract
The flower-infecting fungus Ustilaginoidea virens causes rice false smut, which is a severe emerging disease threatening rice (Oryza sativa) production worldwide. False smut not only reduces yield, but more importantly produces toxins on grains, posing a great threat to food safety. U. virens invades spikelets via the gap between the 2 bracts (lemma and palea) enclosing the floret and specifically infects the stamen and pistil. Molecular mechanisms for the U. virens-rice interaction are largely unknown. Here, we demonstrate that rice flowers predominantly employ chitin-triggered immunity against U. virens in the lemma and palea, rather than in the stamen and pistil. We identify a crucial U. virens virulence factor, named UvGH18.1, which carries glycoside hydrolase activity. Mechanistically, UvGH18.1 functions by binding to and hydrolyzing immune elicitor chitin and interacting with the chitin receptor CHITIN ELICITOR BINDING PROTEIN (OsCEBiP) and co-receptor CHITIN ELICITOR RECEPTOR KINASE1 (OsCERK1) to impair their chitin-induced dimerization, suppressing host immunity exerted at the lemma and palea for gaining access to the stamen and pistil. Conversely, pretreatment on spikelets with chitin induces a defense response in the lemma and palea, promoting resistance against U. virens. Collectively, our data uncover a mechanism for a U. virens virulence factor and the critical location of the host-pathogen interaction in flowers and provide a potential strategy to control rice false smut disease.
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Affiliation(s)
- Guo-Bang Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Jie Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jia-Xue He
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Gao-Meng Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Ya-Dan Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiao-Ling Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xiao-Hong Hu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University, Mianyang 621023, China
| | - Xin Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jin-Long Wu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Shuai Shen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xin-Xian Liu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yong Zhu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Feng He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Han Gao
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - He Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing-Hao Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan Li
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Fu Huang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yan-Yan Huang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Zhi-Xue Zhao
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Ji-Wei Zhang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Shi-Xin Zhou
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Yun-Peng Ji
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Mei Pu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Min He
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Xuewei Chen
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Weitao Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Xian-Jun Wu
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Yuese Ning
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Wenxian Sun
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Zheng-Jun Xu
- Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Sichuan Agricultural University, Chengdu 611130, China
- Yazhouwan National Laboratory, Sanya 572024, China
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Herter SO, Haase H, Koch M. First Synthesis of Ergotamine- 13CD 3 and Ergotaminine- 13CD 3 from Unlabeled Ergotamine. Toxins (Basel) 2024; 16:199. [PMID: 38668624 PMCID: PMC11053779 DOI: 10.3390/toxins16040199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 04/16/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024] Open
Abstract
Ergot alkaloids (EAs) formed by Claviceps fungi are one of the most common food contaminants worldwide, affecting cereals such as rye, wheat, and barley. To accurately determine the level of contamination and to monitor EAs maximum levels set by the European Union, the six most common EAs (so-called priority EAs) and their corresponding epimers are quantified using high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). The quantification of EAs in complex food matrices without appropriate internal standards is challenging but currently carried out in the standard method EN 17425:2021 due to their commercial unavailability. To address the need for isotopically labeled EAs, we focus on two semi-synthetic approaches for the synthesis of these reference standards. Therefore, we investigate the feasibility of the N6-demethylation of native ergotamine to yield norergotamine, which can subsequently be remethylated with an isotopically labeled methylating reagent, such as iodomethane (13CD3-I), to yield isotopically labeled ergotamine and its C8-epimer ergotaminine. Testing the isotopically labeled ergotamine/-inine against native ergotamine/-inine with HPLC coupled to high-resolution HR-MS/MS proved the structure of ergotamine-13CD3 and ergotaminine-13CD3. Thus, for the first time, we can describe their synthesis from unlabeled, native ergotamine. Furthermore, this approach is promising as a universal way to synthesize other isotopically labeled EAs.
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Affiliation(s)
- Sven-Oliver Herter
- Division 1.7, Organic Trace and Food Analysis, Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Str. 11, 12489 Berlin, Germany;
| | - Hajo Haase
- Department of Food Chemistry and Toxicology, Technische Universität Berlin, Gustav-Meyer-Allee 25, 13355 Berlin, Germany;
| | - Matthias Koch
- Division 1.7, Organic Trace and Food Analysis, Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Str. 11, 12489 Berlin, Germany;
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3
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Tetz V, Kardava K, Krasnov K, Vecherkovskaya M, Tetz G. Antifungal activity of a novel synthetic polymer M451 against phytopathogens. Front Microbiol 2023; 14:1176428. [PMID: 37275130 PMCID: PMC10235499 DOI: 10.3389/fmicb.2023.1176428] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/09/2023] [Indexed: 06/07/2023] Open
Abstract
Phytopathogenic fungi are the predominant causal agents of plant diseases. Available fungicides have substantial disadvantages, such as being insufficiently effective owing to intrinsic tolerance and the spread of antifungal resistance accumulating in plant tissues, posing a global threat to public health. Therefore, finding a new broad-spectrum fungicide is a challenge to protect plants. We studied the potency of a novel antimicrobial agent, M451, a 1,6-diaminohexane derivative, against different phytopathogenic fungi of the Ascomycota, Oomycota, and Basidiomycota phyla. M451 exhibited significant antifungal activity with EC50 values from 34-145 μg/mL. The minimal fungicidal concentration against Fusarium oxysporum ranged from 4 to 512 μg/mL depending on the exposure times of 5 min to 24 h. M451 has the highest activity and significantly lower exposure times compared to different polyene, azole, and phenylpyrrole antifungals. The conidial germination assay revealed that M451 induced 99 and 97.8% inhibition against F. oxysporum within 5 min of exposure to 5,000 and 500 μg/mL, respectively. Germ tube elongation, spore production, and spore germination were also significantly inhibited by M451 at concentrations of ≥50 μg/mL. Based on the broad spectrum of antifungal effects across different plant pathogens, M451 could be a new chemical fungicide for plant disease management.
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Effective Pollen-Fertility Restoration Is the Basis of Hybrid Rye Production and Ergot Mitigation. PLANTS 2022; 11:plants11091115. [PMID: 35567115 PMCID: PMC9104404 DOI: 10.3390/plants11091115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/16/2022] [Accepted: 04/17/2022] [Indexed: 11/16/2022]
Abstract
Hybrid rye breeding leads to considerably higher grain yield and a higher revenue to the farmer. The basis of hybrid seed production is the CMS-inducing Pampa (P) cytoplasm derived from an Argentinean landrace and restorer-to-fertility (Rf) genes. European sources show an oligogenic inheritance, with major and minor Rf genes, and mostly result in low-to-moderate pollen-fertility levels. This results in higher susceptibility to ergot (Claviceps purpurea) because rye pollen and ergot spores are in strong competition for the unfertilized stigma. Rf genes from non-adapted Iranian primitive rye and old Argentinean cultivars proved to be most effective. The major Rf gene in these sources was localized on chromosome 4RL, which is also a hotspot of restoration in other Triticeae. Marker-based introgression into elite rye materials led to a yield penalty and taller progenies. The Rfp1 gene of IRAN IX was fine-mapped, and two linked genes of equal effects were detected. Commercial hybrids with this gene showed a similar low ergot infection when compared with population cultivars. The task of the future is to co-adapt these exotic Rfp genes to European elite gene pools by genomic-assisted breeding.
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5
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Tente E, Carrera E, Gordon A, Boyd LA. The Role of the Wheat Reduced height ( Rht)-DELLA Mutants and Associated Hormones in Infection by Claviceps purpurea, the Causal Agent of Ergot. PHYTOPATHOLOGY 2022; 112:842-851. [PMID: 34698539 DOI: 10.1094/phyto-05-21-0189-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Partial resistance to the biotrophic fungal pathogen Claviceps purpurea, causal agent of ergot, has been found that colocates with mutant alleles of the wheat Reduced height (Rht) loci on chromosomes 4B and 4D. These Rht loci represent the wheat orthologs of the Arabidopsis Della genes. To investigate the role of the Rht mutant DELLA proteins in ergot resistance, we assessed C. purpurea infection in wheat near-isogenic lines (NILs) carrying the gibberellic acid (GA)-insensitive semidwarf alleles Rht-B1b and Rht-D1b and the severe dwarf alleles Rht-B1c and Rht-D1c. NILs of the GA-sensitive alleles Rht8 (chromosome 2D) and Rht12 (chromosome 5A) were also included. A general trend toward increased resistance to C. purpurea, with smaller and lighter sclerotia, was observed on the NILs Rht-B1b, Rht-D1b, Rht-B1c, and Rht-D1c, and also on Rht8. Levels of the bioactive GA4 and the auxin indole-3-acetic acid increased after inoculation with C. purpurea, following similar patterns and implicating a potential auxin-mediated induction of GA biosynthesis. In contrast, jasmonic acid (JA) levels fell in the parental lines 'Mercia' and 'Maris Huntsman' after inoculation with C. purpurea, but increased in all the Rht-mutant NILs. Inoculation with C. purpurea did not show any informative changes in the levels of salicylic acid. Our results suggest that GA-mediated degradation of the DELLA proteins and down-regulation of JA-signaling pathways supports infection of wheat by C. purpurea. As these responses are generally associated with necrotrophic fungal pathogens, we propose that the biotroph C. purpurea may have a necrotrophic growth stage.
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Affiliation(s)
- Eleni Tente
- National Institute of Agricultural Botany, Cambridge CB3 0LE, United Kingdom
| | - Esther Carrera
- Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas, Universidad Politécnica de Valencia, Valencia 46022, Spain
| | - Anna Gordon
- National Institute of Agricultural Botany, Cambridge CB3 0LE, United Kingdom
| | - Lesley A Boyd
- National Institute of Agricultural Botany, Cambridge CB3 0LE, United Kingdom
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6
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Connolly JA, Harcombe WR, Smanski MJ, Kinkel LL, Takano E, Breitling R. Harnessing intercellular signals to engineer the soil microbiome. Nat Prod Rep 2021; 39:311-324. [PMID: 34850800 DOI: 10.1039/d1np00034a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Covering: Focus on 2015 to 2020Plant and soil microbiomes consist of diverse communities of organisms from across kingdoms and can profoundly affect plant growth and health. Natural product-based intercellular signals govern important interactions between microbiome members that ultimately regulate their beneficial or harmful impacts on the plant. Exploiting these evolved signalling circuits to engineer microbiomes towards beneficial interactions with crops is an attractive goal. There are few reports thus far of engineering the intercellular signalling of microbiomes, but this article argues that it represents a tremendous opportunity for advancing the field of microbiome engineering. This could be achieved through the selection of synergistic consortia in combination with genetic engineering of signal pathways to realise an optimised microbiome.
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Affiliation(s)
- Jack A Connolly
- Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, Faculty of Science and Engineering, School of Natural Sciences, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK.
| | - William R Harcombe
- BioTechnology Institute, University of Minnesota, Twin-Cities, Saint Paul, MN55108, USA.,Department of Evolution, and Behaviour, University of Minnesota, Twin-Cities Saint Paul, MN55108, USA
| | - Michael J Smanski
- BioTechnology Institute, University of Minnesota, Twin-Cities, Saint Paul, MN55108, USA.,Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Twin-Cities, Saint Paul, MN55108, USA
| | - Linda L Kinkel
- BioTechnology Institute, University of Minnesota, Twin-Cities, Saint Paul, MN55108, USA.,Department of Plant Pathology, University of Minnesota, Twin-Cities, Saint Paul, MN 55108, USA
| | - Eriko Takano
- Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, Faculty of Science and Engineering, School of Natural Sciences, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK.
| | - Rainer Breitling
- Manchester Institute of Biotechnology, Manchester Synthetic Biology Research Centre SYNBIOCHEM, Faculty of Science and Engineering, School of Natural Sciences, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, UK.
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7
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Oberti H, Spangenberg G, Cogan N, Reyno R, Feijoo M, Murchio S, Dalla-Rizza M. Genome-wide analysis of Claviceps paspali: insights into the secretome of the main species causing ergot disease in Paspalum spp. BMC Genomics 2021; 22:766. [PMID: 34702162 PMCID: PMC8549174 DOI: 10.1186/s12864-021-08077-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/11/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The phytopatogen Claviceps paspali is the causal agent of Ergot disease in Paspalum spp., which includes highly productive forage grasses such as P. dilatatum. This disease impacts dairy and beef production by affecting seed quality and producing mycotoxins that can affect performance in feeding animals. The molecular basis of pathogenicity of C. paspali remains unknown, which makes it more difficult to find solutions for this problem. Secreted proteins are related to fungi virulence and can manipulate plant immunity acting on different subcellular localizations. Therefore, identifying and characterizing secreted proteins in phytopathogenic fungi will provide a better understanding of how they overcome host defense and cause disease. The aim of this work is to analyze the whole genome sequences of three C. paspali isolates to obtain a comparative genome characterization based on possible secreted proteins and pathogenicity factors present in their genome. In planta RNA-seq analysis at an early stage of the interaction of C. paspali with P. dilatatum stigmas was also conducted in order to determine possible secreted proteins expressed in the infection process. RESULTS C. paspali isolates had compact genomes and secretome which accounted for 4.6-4.9% of the predicted proteomes. More than 50% of the predicted secretome had no homology to known proteins. RNA-Seq revealed that three protein-coding genes predicted as secreted have mayor expression changes during 1 dpi vs 4 dpi. Also, three of the first 10 highly expressed genes in both time points were predicted as effector-like. CAZyme-like proteins were found in the predicted secretome and the most abundant family could be associated to pectine degradation. Based on this, pectine could be a main component affected by the cell wall degrading enzymes of C. paspali. CONCLUSIONS Based on predictions from DNA sequence and RNA-seq, unique probable secreted proteins and probable pathogenicity factors were identified in C. paspali isolates. This information opens new avenues in the study of the biology of this fungus and how it modulates the interaction with its host. Knowledge of the diversity of the secretome and putative pathogenicity genes should facilitate future research in disease management of Claviceps spp.
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Affiliation(s)
- H Oberti
- Instituto Nacional de Investigación Agropecuaria (INIA). Unidad de Biotecnología. Estación Experimental INIA Las Brujas, Ruta 48 km, 10, Canelones, Uruguay
| | - G Spangenberg
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Bundoora, VIC, 3083, Australia
- School of Applied Systems Biology, La Trobe University, 5 Ring Road, Bundoora, VIC, 3083, Australia
| | - N Cogan
- Agriculture Victoria, AgriBio, Centre for AgriBioscience, 5 Ring Road, Bundoora, VIC, 3083, Australia
- School of Applied Systems Biology, La Trobe University, 5 Ring Road, Bundoora, VIC, 3083, Australia
| | - R Reyno
- Instituto Nacional de Investigación Agropecuaria (INIA). Programa Pasturas y Forrajes. Estación Experimental INIA Tacuarembó, Ruta 5 km, 386, Tacuarembó, Uruguay
| | - M Feijoo
- Centro Universitario Regional del Este (CURE), Polo de Desarrollo Universitario: Patogenicidad, toxicidad y genética en los ecosistemas pastoriles de la región Este de Uruguay, Ruta 8 km, 281, Treinta y Tres, Uruguay
| | - S Murchio
- Instituto Nacional de Investigación Agropecuaria (INIA). Unidad de Biotecnología. Estación Experimental INIA Las Brujas, Ruta 48 km, 10, Canelones, Uruguay
| | - M Dalla-Rizza
- Instituto Nacional de Investigación Agropecuaria (INIA). Unidad de Biotecnología. Estación Experimental INIA Las Brujas, Ruta 48 km, 10, Canelones, Uruguay.
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Boysen JM, Saeed N, Hillmann F. Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus. Beilstein J Org Chem 2021; 17:1814-1827. [PMID: 34394757 PMCID: PMC8336654 DOI: 10.3762/bjoc.17.124] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 07/14/2021] [Indexed: 11/30/2022] Open
Abstract
The kingdom of fungi comprises a large and highly diverse group of organisms that thrive in diverse natural environments. One factor to successfully confront challenges in their natural habitats is the capability to synthesize defensive secondary metabolites. The genetic potential for the production of secondary metabolites in fungi is high and numerous potential secondary metabolite gene clusters have been identified in sequenced fungal genomes. Their production may well be regulated by specific ecological conditions, such as the presence of microbial competitors, symbionts or predators. Here we exemplarily summarize our current knowledge on identified secondary metabolites of the pathogenic fungus Aspergillus fumigatus and their defensive function against (microbial) predators.
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Affiliation(s)
- Jana M Boysen
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Nauman Saeed
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany
| | - Falk Hillmann
- Junior Research Group Evolution of Microbial Interactions, Leibniz-Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), Beutenbergstr. 11a, 07745 Jena, Germany
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9
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Tente E, Ereful N, Rodriguez AC, Grant P, O'Sullivan DM, Boyd LA, Gordon A. Reprogramming of the wheat transcriptome in response to infection with Claviceps purpurea, the causal agent of ergot. BMC PLANT BIOLOGY 2021; 21:316. [PMID: 34215204 PMCID: PMC8252325 DOI: 10.1186/s12870-021-03086-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/07/2021] [Indexed: 06/02/2023]
Abstract
BACKGROUND Ergot, caused by the fungal pathogen Claviceps purpurea, infects the female flowers of a range of cereal crops, including wheat. To understand the interaction between C. purpurea and hexaploid wheat we undertook an extensive examination of the reprogramming of the wheat transcriptome in response to C. purpurea infection through floral tissues (i.e. the stigma, transmitting and base ovule tissues of the ovary) and over time. RESULTS C. purpurea hyphae were observed to have grown into and down the stigma at 24 h (H) after inoculation. By 48H hyphae had grown through the transmitting tissue into the base, while by 72H hyphae had surrounded the ovule. By 5 days (D) the ovule had been replaced by fungal tissue. Differential gene expression was first observed at 1H in the stigma tissue. Many of the wheat genes differentially transcribed in response to C. purpurea infection were associated with plant hormones and included the ethylene (ET), auxin, cytokinin, gibberellic acid (GA), salicylic acid and jasmonic acid (JA) biosynthetic and signaling pathways. Hormone-associated genes were first detected in the stigma and base tissues at 24H, but not in the transmitting tissue. Genes associated with GA and JA pathways were seen in the stigma at 24H, while JA and ET-associated genes were identified in the base at 24H. In addition, several defence-related genes were differential expressed in response to C. purpurea infection, including antifungal proteins, endocytosis/exocytosis-related proteins, NBS-LRR class proteins, genes involved in programmed cell death, receptor protein kinases and transcription factors. Of particular interest was the identification of differential expression of wheat genes in the base tissue well before the appearance of fungal hyphae, suggesting that a mobile signal, either pathogen or plant-derived, is delivered to the base prior to colonisation. CONCLUSIONS Multiple host hormone biosynthesis and signalling pathways were significantly perturbed from an early stage in the wheat - C. purpurea interaction. Differential gene expression at the base of the ovary, ahead of arrival of the pathogen, indicated the potential presence of a long-distance signal modifying host gene expression.
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Affiliation(s)
- Eleni Tente
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
| | - Nelzo Ereful
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
- Philippine Genome Center, Plant Physiology Laboratory, Institute of Plant Breeding, University of the Philippines, Los Baños, Laguna, The Philippines
| | | | - Paul Grant
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA, UK
- Present Address: Microsoft Research, 21 Station Road, Cambridge, CB1 2FB, UK
| | - Donal M O'Sullivan
- School of Agriculture, Policy and Development, University of Reading, Whiteknights, Reading, RG6 6AR, UK
| | - Lesley A Boyd
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK.
| | - Anna Gordon
- NIAB, 93 Lawrence Weaver Road, Cambridge, CB3 0LE, UK
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10
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Wyka SA, Mondo SJ, Liu M, Dettman J, Nalam V, Broders KD. Whole-Genome Comparisons of Ergot Fungi Reveals the Divergence and Evolution of Species within the Genus Claviceps Are the Result of Varying Mechanisms Driving Genome Evolution and Host Range Expansion. Genome Biol Evol 2021; 13:evaa267. [PMID: 33512490 PMCID: PMC7883665 DOI: 10.1093/gbe/evaa267] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/16/2020] [Indexed: 12/26/2022] Open
Abstract
The genus Claviceps has been known for centuries as an economically important fungal genus for pharmacology and agricultural research. Only recently have researchers begun to unravel the evolutionary history of the genus, with origins in South America and classification of four distinct sections through ecological, morphological, and metabolic features (Claviceps sects. Citrinae, Paspalorum, Pusillae, and Claviceps). The first three sections are additionally characterized by narrow host range, whereas section Claviceps is considered evolutionarily more successful and adaptable as it has the largest host range and biogeographical distribution. However, the reasons for this success and adaptability remain unclear. Our study elucidates factors influencing adaptability by sequencing and annotating 50 Claviceps genomes, representing 21 species, for a comprehensive comparison of genome architecture and plasticity in relation to host range potential. Our results show the trajectory from specialized genomes (sects. Citrinae and Paspalorum) toward adaptive genomes (sects. Pusillae and Claviceps) through colocalization of transposable elements around predicted effectors and a putative loss of repeat-induced point mutation resulting in unconstrained tandem gene duplication coinciding with increased host range potential and speciation. Alterations of genomic architecture and plasticity can substantially influence and shape the evolutionary trajectory of fungal pathogens and their adaptability. Furthermore, our study provides a large increase in available genomic resources to propel future studies of Claviceps in pharmacology and agricultural research, as well as, research into deeper understanding of the evolution of adaptable plant pathogens.
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Affiliation(s)
- Stephen A Wyka
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Stephen J Mondo
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
- U.S. Department of Energy Joint Genome Institute, Berkeley, California, USA
| | - Miao Liu
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada
| | - Jeremy Dettman
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, Canada
| | - Vamsi Nalam
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
| | - Kirk D Broders
- Department of Agricultural Biology, Colorado State University, Fort Collins, Colorado, USA
- Smithsonian Tropical Research Institute, Panamá, República de Panamá
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11
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Inserra A, De Gregorio D, Gobbi G. Psychedelics in Psychiatry: Neuroplastic, Immunomodulatory, and Neurotransmitter Mechanisms. Pharmacol Rev 2020; 73:202-277. [PMID: 33328244 DOI: 10.1124/pharmrev.120.000056] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mounting evidence suggests safety and efficacy of psychedelic compounds as potential novel therapeutics in psychiatry. Ketamine has been approved by the Food and Drug Administration in a new class of antidepressants, and 3,4-methylenedioxymethamphetamine (MDMA) is undergoing phase III clinical trials for post-traumatic stress disorder. Psilocybin and lysergic acid diethylamide (LSD) are being investigated in several phase II and phase I clinical trials. Hence, the concept of psychedelics as therapeutics may be incorporated into modern society. Here, we discuss the main known neurobiological therapeutic mechanisms of psychedelics, which are thought to be mediated by the effects of these compounds on the serotonergic (via 5-HT2A and 5-HT1A receptors) and glutamatergic [via N-methyl-d-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors] systems. We focus on 1) neuroplasticity mediated by the modulation of mammalian target of rapamycin-, brain-derived neurotrophic factor-, and early growth response-related pathways; 2) immunomodulation via effects on the hypothalamic-pituitary-adrenal axis, nuclear factor ĸB, and cytokines such as tumor necrosis factor-α and interleukin 1, 6, and 10 production and release; and 3) modulation of serotonergic, dopaminergic, glutamatergic, GABAergic, and norepinephrinergic receptors, transporters, and turnover systems. We discuss arising concerns and ways to assess potential neurobiological changes, dependence, and immunosuppression. Although larger cohorts are required to corroborate preliminary findings, the results obtained so far are promising and represent a critical opportunity for improvement of pharmacotherapies in psychiatry, an area that has seen limited therapeutic advancement in the last 20 years. Studies are underway that are trying to decouple the psychedelic effects from the therapeutic effects of these compounds. SIGNIFICANCE STATEMENT: Psychedelic compounds are emerging as potential novel therapeutics in psychiatry. However, understanding of molecular mechanisms mediating improvement remains limited. This paper reviews the available evidence concerning the effects of psychedelic compounds on pathways that modulate neuroplasticity, immunity, and neurotransmitter systems. This work aims to be a reference for psychiatrists who may soon be faced with the possibility of prescribing psychedelic compounds as medications, helping them assess which compound(s) and regimen could be most useful for decreasing specific psychiatric symptoms.
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Affiliation(s)
- Antonio Inserra
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Danilo De Gregorio
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, Department of Psychiatry, McGill University, Montreal, Quebec, Canada
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Sun W, Fan J, Fang A, Li Y, Tariqjaveed M, Li D, Hu D, Wang WM. Ustilaginoidea virens: Insights into an Emerging Rice Pathogen. ANNUAL REVIEW OF PHYTOPATHOLOGY 2020; 58:363-385. [PMID: 32364825 DOI: 10.1146/annurev-phyto-010820-012908] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
False smut of rice, caused by Ustilaginoidea virens, has become one of the most important diseases in rice-growing regions worldwide. The disease causes a significant yield loss and imposes health threats to humans and animals by producing mycotoxins. In this review, we update our understanding of the pathogen, including the disease cycle and infection strategies, the decoding of the U. virens genome, comparative/functional genomics, and effector biology. Whereas the decoding of the U. virens genome unveils specific adaptations of the pathogen in successfully occupying rice flowers, progresses in comparative/functional genomics and effector biology have begun to uncover the molecular mechanisms underlying U. virens virulence and pathogenicity. We highlight the identification and characterization of the produced mycotoxins and their biosynthetic pathways in U. virens.The management strategies for this disease are also discussed. The flower-specific infection strategy makes the pathogen a unique tool to unveil novel mechanisms for the interactions between nonobligate biotrophic pathogens and their hosts.
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Affiliation(s)
- Wenxian Sun
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Jing Fan
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
| | - Anfei Fang
- College of Plant Protection, Southwest University, Chongqing 400715, China
| | - Yuejiao Li
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Muhammad Tariqjaveed
- College of Plant Protection and the Ministry of Agriculture Key Laboratory of Pest Monitoring and Green Management, China Agricultural University, Beijing 100193, China
| | - Dayong Li
- College of Plant Protection, Jilin Agricultural University, Changchun 130118, China;
| | - Dongwei Hu
- State Key Laboratory of Rice Biology, Biotechnology Institute, Zhejiang University, Hangzhou 310058, China
| | - Wen-Ming Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, Rice Research Institute, Sichuan Agricultural University, Chengdu 611130, China;
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Mahmood K, Orabi J, Kristensen PS, Sarup P, Jørgensen LN, Jahoor A. De novo transcriptome assembly, functional annotation, and expression profiling of rye (Secale cereale L.) hybrids inoculated with ergot (Claviceps purpurea). Sci Rep 2020; 10:13475. [PMID: 32778722 PMCID: PMC7417550 DOI: 10.1038/s41598-020-70406-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 07/24/2020] [Indexed: 12/22/2022] Open
Abstract
Rye is used as food, feed, and for bioenergy production and remain an essential grain crop for cool temperate zones in marginal soils. Ergot is known to cause severe problems in cross-pollinated rye by contamination of harvested grains. The molecular response of the underlying mechanisms of this disease is still poorly understood due to the complex infection pattern. RNA sequencing can provide astonishing details about the transcriptional landscape, hence we employed a transcriptomic approach to identify genes in the underlying mechanism of ergot infection in rye. In this study, we generated de novo assemblies from twelve biological samples of two rye hybrids with identified contrasting phenotypic responses to ergot infection. The final transcriptome of ergot susceptible (DH372) and moderately ergot resistant (Helltop) hybrids contain 208,690 and 192,116 contigs, respectively. By applying the BUSCO pipeline, we confirmed that these transcriptome assemblies contain more than 90% of gene representation of the available orthologue groups at Virdiplantae odb10. We employed a de novo assembled and the draft reference genome of rye to count the differentially expressed genes (DEGs) between the two hybrids with and without inoculation. The gene expression comparisons revealed that 228 genes were linked to ergot infection in both hybrids. The genome ontology enrichment analysis of DEGs associated them with metabolic processes, hydrolase activity, pectinesterase activity, cell wall modification, pollen development and pollen wall assembly. In addition, gene set enrichment analysis of DEGs linked them to cell wall modification and pectinesterase activity. These results suggest that a combination of different pathways, particularly cell wall modification and pectinesterase activity contribute to the underlying mechanism that might lead to resistance against ergot in rye. Our results may pave the way to select genetic material to improve resistance against ergot through better understanding of the mechanism of ergot infection at molecular level. Furthermore, the sequence data and de novo assemblies are valuable as scientific resources for future studies in rye.
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Affiliation(s)
- Khalid Mahmood
- Nordic Seed A/S, Grindsnabevej 25, 8300, Odder, Denmark. .,Department of Agroecology, Faculty of Science and Technology, Aarhus University, Forsøgsvej 1, Flakkebjerg, 4200, Slagelse, Denmark.
| | - Jihad Orabi
- Nordic Seed A/S, Grindsnabevej 25, 8300, Odder, Denmark
| | | | | | - Lise Nistrup Jørgensen
- Department of Agroecology, Faculty of Science and Technology, Aarhus University, Forsøgsvej 1, Flakkebjerg, 4200, Slagelse, Denmark
| | - Ahmed Jahoor
- Nordic Seed A/S, Grindsnabevej 25, 8300, Odder, Denmark.,Department of Plant Breeding, The Swedish University of Agricultural Sciences, 23053, Alnarp, Sweden
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Eisermann I, Motyka V, Kümmel S, Dobrev PI, Hübner K, Deising HB, Wirsel SGR. CgIPT1 is required for synthesis of cis-zeatin cytokinins and contributes to stress tolerance and virulence in Colletotrichum graminicola. Fungal Genet Biol 2020; 143:103436. [PMID: 32693088 DOI: 10.1016/j.fgb.2020.103436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 06/09/2020] [Accepted: 07/14/2020] [Indexed: 10/23/2022]
Abstract
We have previously shown that the maize pathogen Colletotrichum graminicola is able to synthesise cytokinins (CKs). However, it remained unsettled whether fungal CK production is essential for virulence in this hemibiotrophic fungus. Here, we identified a candidate gene, CgIPT1, that is homologous to MOD5 of Saccharomyces cerevisiae and genes from other fungi and plants, which encode tRNA-isopentenyltransferases (IPTs). We show that the wild type strain mainly synthesises cis-zeatin-type (cisZ) CKs whereas ΔCgipt1 mutants are severely impeded to do so. The spectrum of CKs produced confirms bioinformatical analyses predicting that CgIpt1 is a tRNA-IPT. The virulence of the ΔCgipt1 mutants is moderately reduced. Furthermore, the mutants exhibit increased sensitivities to osmotic stress imposed by sugar alcohols and salts, as well as cell wall stress imposed by Congo red. Amendment of media with CKs did not reverse this phenotype suggesting that fungal-derived CKs do not explain the role of CgIpt1 in mediating abiotic stress tolerance. Moreover, the mutants still cause green islands on senescing maize leaves indicating that the cisZ-type CKs produced by the fungus do not cause this phenotype.
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Affiliation(s)
- Iris Eisermann
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120 Halle (Saale), Germany
| | - Václav Motyka
- Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
| | - Stefanie Kümmel
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120 Halle (Saale), Germany
| | - Petre I Dobrev
- Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, CZ-165 02 Prague 6, Czech Republic
| | - Konstantin Hübner
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120 Halle (Saale), Germany
| | - Holger B Deising
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120 Halle (Saale), Germany
| | - Stefan G R Wirsel
- Institut für Agrar- und Ernährungswissenschaften, Naturwissenschaftliche Fakultät III, Martin-Luther-Universität Halle-Wittenberg, Betty-Heimann-Str. 3, D-06120 Halle (Saale), Germany.
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15
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Dung JKS, Scott JC, Cheng Q, Alderman SC, Kaur N, Walenta DL, Frost KE, Hamm PB. Detection and Quantification of Airborne Claviceps purpurea sensu lato Ascospores from Hirst-Type Spore Traps using Real-Time Quantitative PCR. PLANT DISEASE 2018; 102:2487-2493. [PMID: 30256180 DOI: 10.1094/pdis-02-18-0310-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The U.S. Pacific Northwest states of Oregon and Washington are major producers of cool-season grass seed. Ergot, caused by fungi in the Claviceps purpurea sensu lato group, is an important seed replacement disease of grass worldwide. Microscopic methods that are currently used to quantify airborne Claviceps ascospores captured by spore traps are not currently rapid enough to allow for detecting and reporting of spore numbers in a timely manner, hindering growers from using this information to help manage ergot. We developed a SYBR Green real-time quantitative polymerase chain reaction (qPCR)-based assay for fast and efficient detection and quantification of C. purpurea sensu lato ascospores from Hirst-type spore traps. Species-specificity of the qPCR assay was confirmed against 41 C. purpurea sensu lato isolates collected from six hosts and six other Claviceps spp. Significant relationships were observed between cycle threshold (Ct) values and standard curves of serial dilutions of DNA ranging from 1 pg to 10 ng (R2 = -0.99; P = 0.0002) and DNA extracted from a conidial suspension representing 8 to 80,000 conidia (R2 = -0.99; P = 0.0004). Ct values from qPCR were significantly correlated with results from microscopic examination of spore trap samples from the field (r = -0.68; P < 0.0001) and the procedure was able to detect a single ascospore from spore trap tape samples. The qPCR procedure developed in this study provided a means for quantifying airborne Claviceps ascospores that was highly specific and useful over a wide range of spore densities, and could be performed in a matter of hours instead of days. The qPCR assay developed in this study could be part of an integrated pest management approach to help grass seed growers make risk-based fungicide application decisions for ergot management in grass grown for seed.
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Affiliation(s)
- Jeremiah K S Dung
- Department of Botany and Plant Pathology, Central Oregon Agricultural Research Center, Oregon State University, Madras
| | - Jeness C Scott
- Department of Botany and Plant Pathology, Central Oregon Agricultural Research Center, Oregon State University, Madras
| | - Qunkang Cheng
- Department of Botany and Plant Pathology, Central Oregon Agricultural Research Center, Oregon State University, Madras
| | - Stephen C Alderman
- National Forage Seed Production Research Center, United States Department of Agriculture-Agricultural Research Service, Corvallis, OR
| | - Navneet Kaur
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston
| | - Darrin L Walenta
- Union County Extension Service, Oregon State University, La Grande
| | - Kenneth E Frost
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston
| | - Philip B Hamm
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston
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Somppi TL. Non-Thyroidal Illness Syndrome in Patients Exposed to Indoor Air Dampness Microbiota Treated Successfully with Triiodothyronine. Front Immunol 2017; 8:919. [PMID: 28824644 PMCID: PMC5545575 DOI: 10.3389/fimmu.2017.00919] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 07/20/2017] [Indexed: 01/21/2023] Open
Abstract
Long-term exposure to dampness microbiota induces multi-organ morbidity. One of the symptoms related to this disorder is non-thyroidal illness syndrome (NTIS). A retrospective study was carried out in nine patients with a history of mold exposure, experiencing chronic fatigue, cognitive disorder, and different kinds of hypothyroid symptoms despite provision of levothyroxine (3,5,3',5'-tetraiodothyronine, LT4) monotherapy. Exposure to volatile organic compounds present in water-damaged buildings including metabolic products of toxigenic fungi and mold-derived inflammatory agents can lead to a deficiency or imbalance of many hormones, such as active T3 hormone. Since the 1970s, the synthetic prohormone, levothyroxine (LT4), has been the most commonly prescribed thyroid hormone in replacement monotherapy. It has been presumed that the peripheral conversion of T4 (3,5,3',5'-tetraiodothyronine) into T3 (3,5,3'-triiodothyronine) is sufficient to satisfy the overall tissue requirements. However, evidence is presented that this not the case for all patients, especially those exposed to indoor air molds. This retrospective study describes the successful treatment of nine patients in whom NTIS was treated with T3-based thyroid hormone. The treatment was based on careful interview, clinical monitoring, and laboratory analysis of serum free T3 (FT3), reverse T3 (rT3) and thyroid-stimulating hormone, free T4, cortisol, and dehydroepiandrosterone (DHEA) values. The ratio of FT3/rT3 was calculated. In addition, some patients received adrenal support with hydrocortisone and DHEA. All patients received nutritional supplementation and dietary instructions. During the therapy, all nine patients reported improvements in all of the symptom groups. Those who had residual symptoms during T3-based therapy remained exposed to indoor air molds in their work places. Four patients were unable to work and had been on disability leave for a long time during LT4 monotherapy. However, during the T3-based and supportive therapy, all patients returned to work in so-called "healthy" buildings. The importance of avoiding mycotoxin exposure via the diet is underlined as DIO2 genetic polymorphism and dysfunction of DIO2 play an important role in the development of symptoms that can be treated successfully with T3 therapy.
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Abstract
Fungi are among the dominant causal agents of plant diseases. To colonize plants and cause disease, pathogenic fungi use diverse strategies. Some fungi kill their hosts and feed on dead material (necrotrophs), while others colonize the living tissue (biotrophs). For successful invasion of plant organs, pathogenic development is tightly regulated and specialized infection structures are formed. To further colonize hosts and establish disease, fungal pathogens deploy a plethora of virulence factors. Depending on the infection strategy, virulence factors perform different functions. While basically all pathogens interfere with primary plant defense, necrotrophs secrete toxins to kill plant tissue. In contrast, biotrophs utilize effector molecules to suppress plant cell death and manipulate plant metabolism in favor of the pathogen. This article provides an overview of plant pathogenic fungal species and the strategies they use to cause disease.
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Abstract
While fungi can make positive contributions to ecosystems and agro-ecosystems, for example, in mycorrhizal associations, they can also have devastating impacts as pathogens of plants and animals. In undisturbed ecosystems, most such negative interactions will be limited through the coevolution of fungi with their hosts. In this article, we explore what happens when pathogenic fungi spread beyond their natural ecological range and become invasive on naïve hosts in new ecosystems. We will see that such invasive pathogens have been problematic to humans and their domesticated plant and animal species throughout history, and we will discuss some of the most pressing fungal threats of today.
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Dung JKS, Alderman SC, Kaur N, Walenta DL, Frost KE, Hamm PB. Identification of Environmental Factors Related to Claviceps purpurea Ascospore Production in Perennial Ryegrass Seed Fields and Development of Predictive Models. PLANT DISEASE 2017; 101:895-906. [PMID: 30682939 DOI: 10.1094/pdis-05-16-0609-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Claviceps purpurea, the causal agent of ergot of perennial ryegrass seed crops, overwinters as sclerotia in the soil and releases airborne ascospores in the spring that infect flower ovaries and replace seed with sclerotia. Burkard spore traps were used to quantify the dispersal phenology and concentration of ascospores in perennial ryegrass seed fields in the Columbia Basin of Oregon. Weather factors were measured concurrently with spore trapping. Nonparametric regression, box-and-whisker plots, and univariate analysis were used to visualize and identify trends between ascospore concentrations and weather variables. Most ascospores (75.4%) were trapped when minimum soil temperatures were between 16.2 and 20.4°C. Over 67% of the total ascospores trapped were observed when minimum air temperatures were between 6.8 and 12.4°C and 64% of ascospores were trapped when daily mean dew point was between 3.7 and 8.2°C. Environmental favorability index (EFI) models were developed and validated based on their ability to predict ascospore occurrence. The EFI models were able to predict ascospore occurrence with an accuracy of 71.7 to 87.5% depending on the year. The models were up to 79.8% accurate when validated using three years of historical spore trap data not used in the EFI model development. Ninety-four percent of ascospores were trapped when cumulative air degree days, using lower and upper thresholds of 10 and 25°C, respectively, were between 230 and 403. These results suggest that weather parameters can be used to model C. purpurea ascospore occurrence and potentially improve the timing and efficacy of fungicide applications by identifying when plant protection is most needed.
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Affiliation(s)
- Jeremiah K S Dung
- Department of Botany and Plant Pathology, Central Oregon Agricultural Research Center, Oregon State University, Madras, OR
| | | | - Navneet Kaur
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston, OR
| | - Darrin L Walenta
- Department of Crop and Soil Science, Union County Extension Center, La Grande, OR
| | - Kenneth E Frost
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston, OR
| | - Philip B Hamm
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston, OR
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20
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Oeser B, Kind S, Schurack S, Schmutzer T, Tudzynski P, Hinsch J. Cross-talk of the biotrophic pathogen Claviceps purpurea and its host Secale cereale. BMC Genomics 2017; 18:273. [PMID: 28372538 PMCID: PMC5379732 DOI: 10.1186/s12864-017-3619-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/10/2017] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The economically important Ergot fungus Claviceps purpurea is an interesting biotrophic model system because of its strict organ specificity (grass ovaries) and the lack of any detectable plant defense reactions. Though several virulence factors were identified, the exact infection mechanisms are unknown, e.g. how the fungus masks its attack and if the host detects the infection at all. RESULTS We present a first dual transcriptome analysis using an RNA-Seq approach. We studied both, fungal and plant gene expression in young ovaries infected by the wild-type and two virulence-attenuated mutants. We can show that the plant recognizes the fungus, since defense related genes are upregulated, especially several phytohormone genes. We present a survey of in planta expressed fungal genes, among them several confirmed virulence genes. Interestingly, the set of most highly expressed genes includes a high proportion of genes encoding putative effectors, small secreted proteins which might be involved in masking the fungal attack or interfering with host defense reactions. As known from several other phytopathogens, the C. purpurea genome contains more than 400 of such genes, many of them clustered and probably highly redundant. Since the lack of effective defense reactions in spite of recognition of the fungus could very well be achieved by effectors, we started a functional analysis of some of the most highly expressed candidates. However, the redundancy of the system made the identification of a drastic effect of a single gene most unlikely. We can show that at least one candidate accumulates in the plant apoplast. Deletion of some candidates led to a reduced virulence of C. purpurea on rye, indicating a role of the respective proteins during the infection process. CONCLUSIONS We show for the first time that- despite the absence of effective plant defense reactions- the biotrophic pathogen C. purpurea is detected by its host. This points to a role of effectors in modulation of the effective plant response. Indeed, several putative effector genes are among the highest expressed genes in planta.
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Affiliation(s)
- Birgitt Oeser
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, D-48143 Münster, Germany
| | - Sabine Kind
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, D-48143 Münster, Germany
| | - Selma Schurack
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, D-48143 Münster, Germany
| | - Thomas Schmutzer
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Paul Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, D-48143 Münster, Germany
| | - Janine Hinsch
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität, D-48143 Münster, Germany
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21
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Steiner U, Leibner S, Schardl CL, Leuchtmann A, Leistner E. Periglandula, a new fungal genus within the Clavicipitaceae and its association with Convolvulaceae. Mycologia 2017; 103:1133-45. [DOI: 10.3852/11-031] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Sarah Leibner
- Institut für Nutzpflanzenwissenschaften und Ressourcenschutz (INRES)-Phytomedizin, Rheinische Friedrich Wilhelms-Universität Bonn, Nussallee 9, D-53115 Bonn, Germany
| | - Christopher Lewis Schardl
- Department of Plant Pathology, 201F Plant Sciences Building, 1405 Veterans Drive, University of Kentucky, Lexington, Kentucky 40546-0312
| | - Adrian Leuchtmann
- Plant Ecological Genetics, Institute of Integrative Biology, ETH Zürich, Universitätstrasse 16, CH-8092 Zürich, Switzerland
| | - Eckhard Leistner
- Institut für Pharmazeutische Biologie, Rheinische Friedrich Wilhelms-Universität Bonn, Nussallee 6, D-53115 Bonn, Germany
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Jaroszuk-Ściseł J, Kurek E, Słomka A, Janczarek M, Rodzik B. Activities of cell wall degrading enzymes in autolyzing cultures of three Fusarium culmorum isolates: growth-promoting, deleterious and pathogenic to rye (Secale cereale). Mycologia 2017; 103:929-45. [DOI: 10.3852/10-300] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Anna Słomka
- Department of Environmental Microbiology, Institute of Microbiology and Biotechnology, University of Maria Curie-Skłodowska, Akademicka 19, 20-033, Lublin, Poland
| | - Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, University of Maria Curie-Skłodowska, Akademicka 19, 20-033, Lublin, Poland
| | - Beata Rodzik
- Department of Mathematical Statistics, Institute of Mathematics, University of Maria Curie-Skłodowska, Curie-Skłodowska Sq. 1, 20-031, Lublin, Poland
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23
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Hu D, Li M. Three New Ergot Alkaloids from the Fruiting Bodies of Xylaria nigripes
(Kl
.) Sacc
. Chem Biodivers 2016; 14. [PMID: 27448231 DOI: 10.1002/cbdv.201600173] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 07/18/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Dongbao Hu
- College of Resource and Environment; Yuxi Normal University; Yuxi 653100 P. R. China
- State Key Laboratory of Phytochemistry and Plant Resources in West China; Kunming Institute of Botany; Chinese Academy of Sciences; Lanhei Road 132 Kunming 650201 P. R. China
| | - Ming Li
- College of Resource and Environment; Yuxi Normal University; Yuxi 653100 P. R. China
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24
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Fan J, Yang J, Wang Y, Li G, Li Y, Huang F, Wang W. Current understanding on Villosiclava virens, a unique flower-infecting fungus causing rice false smut disease. MOLECULAR PLANT PATHOLOGY 2016; 17:1321-1330. [PMID: 26720072 PMCID: PMC6638446 DOI: 10.1111/mpp.12362] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Revised: 12/25/2015] [Accepted: 12/27/2015] [Indexed: 05/13/2023]
Abstract
Villosiclava virens (Vv) is an ascomycete fungal pathogen that causes false smut disease in rice. Recent reports have revealed some interesting aspects of the enigmatic pathogen to address the question of why it specifically infects rice flowers and converts a grain into a false smut ball. Comparative and functional genomics have suggested specific adaptation of Vv in the colonization of rice flowers. Anatomical studies have disclosed that Vv specifically infects rice stamen filaments before heading and intercepts seed formation. In addition, Vv can occupy the whole inner space of a spikelet embracing all floral organs and activate the rice grain-filling network, presumably for nutrient acquisition to support the development of the false smut ball. This profile provides a general overview of the rice false smut pathogen, and summarizes advances in the Vv life cycle, genomics and genetics, and the molecular Vv-rice interaction. Current understandings of the Vv-rice pathosystem indicate that it is a unique and interesting system which can enrich the study of plant-pathogen interactions. Taxonomy: Ustilaginoidea virens is the anamorph form of the pathogen (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Incertae sedis; Order Incertae sedis; Family Incertae sedis; Genus Ustilaginoidea). The teleomorph form is Villosiclava virens (Kingdom Fungi; Phylum Ascomycota; Class Ascomycetes; Subclass Sordariomycetes; Order Hypocreales; Family Clavicipitaceae; Genus Villosiclava). Disease symptoms: The only visible symptom is the replacement of rice grains by ball-shaped fungal mycelia, namely false smut balls. When maturing, the false smut ball is covered with powdery chlamydospores, and the colour changes to yellowish, yellowish orange, green, olive green and, finally, to greenish black. Sclerotia are often formed on the false smut balls in autumn. Identification and detection: Vv conidia are round to elliptical, measuring 3-5 μm in diameter. Chlamydospores are ornamented with prominent irregularly curved spines, which are 200-500 nm in length. The sclerotia are black, horseshoe-shaped and irregular oblong or flat, ranging from 2 to 20 mm. Nested polymerase chain reaction (PCR) and quantitative PCR have been developed to specifically detect Vv presence in rice tissues and other biotic and abiotic samples in fields. Host range: Rice is the primary host for Vv. Natural infection by Vv has been found on several paddy field weeds, including Digitaria marginata, Panicum trypheron, Echinochloa crusgalli and Imperata cylindrica. However, the occurrence of infection in these potential alternative hosts is very rare. Life cycle: Vv infects rice spikelets at the late rice booting stage, and produces false smut balls covered with dark-green chlamydospores. Occasionally, sclerotia form on the surface of false smut balls in late autumn when the temperature fluctuates greatly between day and night. Both chlamydospores and sclerotia may serve as primary infection sources. Rainfall at the rice booting stage is a major environmental factor resulting in epidemics of rice false smut disease. Disease control: The use of fungicides is the major approach for the control of Vv. Several fungicides, such as cuproxat SC, copper oxychloride, tebuconazole, propiconazole, difenoconazole and validamycin, are often applied. However, the employment of resistant rice cultivars and genes has been limited, because of the poor understanding of rice resistance to Vv. Useful websites: Villosiclava virens genome sequence: http://www.ncbi.nlm.nih.gov/Traces/wgs/?val=JHTR01#contigs.
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Affiliation(s)
- Jing Fan
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Juan Yang
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Yu‐Qiu Wang
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Guo‐Bang Li
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Yan Li
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
| | - Fu Huang
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
- College of Agronomy & Institute of Agricultural EcologySichuan Agricultural UniversityChengdu611130China
| | - Wen‐Ming Wang
- Rice Research Institute & Key Laboratory for Major Crop DiseasesSichuan Agricultural UniversityChengdu611130China
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25
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Majeská Čudejková M, Vojta P, Valík J, Galuszka P. Quantitative and qualitative transcriptome analysis of four industrial strains of Claviceps purpurea with respect to ergot alkaloid production. N Biotechnol 2016; 33:743-754. [PMID: 26827914 DOI: 10.1016/j.nbt.2016.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/22/2015] [Accepted: 01/05/2016] [Indexed: 01/14/2023]
Abstract
The fungus Claviceps purpurea is a biotrophic phytopathogen widely used in the pharmaceutical industry for its ability to produce ergot alkaloids (EAs). The fungus attacks unfertilized ovaries of grasses and forms sclerotia, which represent the only type of tissue where the synthesis of EAs occurs. The biosynthetic pathway of EAs has been extensively studied; however, little is known concerning its regulation. Here, we present the quantitative transcriptome analysis of the sclerotial and mycelial tissues providing a comprehensive view of transcriptional differences between the tissues that produce EAs and those that do not produce EAs and the pathogenic and non-pathogenic lifestyle. The results indicate metabolic changes coupled with sclerotial differentiation, which are likely needed as initiation factors for EA biosynthesis. One of the promising factors seems to be oxidative stress. Here, we focus on the identification of putative transcription factors and regulators involved in sclerotial differentiation, which might be involved in EA biosynthesis. To shed more light on the regulation of EA composition, whole transcriptome analysis of four industrial strains differing in their alkaloid spectra was performed. The results support the hypothesis proposing the composition of the amino acid pool in sclerotia to be an important factor regulating the final structure of the ergopeptines produced by Claviceps purpurea.
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Affiliation(s)
- Mária Majeská Čudejková
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic.
| | - Petr Vojta
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic; Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University Olomouc, Hněvotínská 1333/5, 779 00 Olomouc, Czech Republic
| | - Josef Valík
- Teva Czech Industries s.r.o., Ostravská 305/29, 747 70 Opava-Komárov, Czech Republic
| | - Petr Galuszka
- Department of Molecular Biology, Centre of the Region Haná for Biotechnological and Agricultural Research, Faculty of Science, Palacký University in Olomouc, Šlechtitelů 27, 783 71 Olomouc, Czech Republic
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26
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Hinsch J, Galuszka P, Tudzynski P. Functional characterization of the first filamentous fungal tRNA-isopentenyltransferase and its role in the virulence of Claviceps purpurea. THE NEW PHYTOLOGIST 2016; 211:980-992. [PMID: 27074411 DOI: 10.1111/nph.13960] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 03/01/2016] [Indexed: 06/05/2023]
Abstract
In plants, cytokinins (CKs) are synthesized de novo or by the degradation of modified tRNAs. Recently, the first fungal de novo pathway was identified within the plant pathogen Claviceps purpurea. As the deletion of the de novo pathway did not lead to a complete loss of CKs, this work focuses on the tRNA-modifying protein tRNA-isopentenyltransferase (CptRNA-IPT). The contribution of this enzyme to the CK pool of Claviceps and the role of CKs in the host-pathogen interaction are emphasized. The effects of the deletion of cptRNA-ipt and the double deletion of cptRNA-ipt and the key gene of de novo biosynthesis cpipt-log on growth, CK biosynthesis and virulence were analyzed. In addition, the sites of action of CptRNA-IPT were visualized using reporter gene fusions. In addition to CK-independent functions, CptRNA-IPT was essential for the biosynthesis of cis-zeatin (cZ) and contributed to the formation of isopentenyladenine (iP) and trans-zeatin (tZ). Although ΔcptRNA-ipt was reduced in virulence, the 'CK-free' double deletion mutant was nearly apathogenic. The results prove a redundancy of the CK biosynthesis pathway in C. purpurea for iP and tZ formation. Moreover, we show, for the first time, that CKs are required for the successful establishment of a host-fungus interaction.
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Affiliation(s)
- Janine Hinsch
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-University Münster, Schlossplatz 8, 48143, Münster, Germany
| | - Petr Galuszka
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University, Šlechtitelů 27, 78371, Olomouc, Czech Republic
| | - Paul Tudzynski
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-University Münster, Schlossplatz 8, 48143, Münster, Germany
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27
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Becker M, Becker Y, Green K, Scott B. The endophytic symbiont Epichloë festucae establishes an epiphyllous net on the surface of Lolium perenne leaves by development of an expressorium, an appressorium-like leaf exit structure. THE NEW PHYTOLOGIST 2016; 211:240-54. [PMID: 26991322 PMCID: PMC5069595 DOI: 10.1111/nph.13931] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Accepted: 02/07/2016] [Indexed: 05/16/2023]
Abstract
Epichloë festucae forms a mutualistic symbiotic association with Lolium perenne. This biotrophic fungus systemically colonizes the intercellular spaces of aerial tissues to form an endophytic hyphal network. E. festucae also grows as an epiphyte, but the mechanism for leaf surface colonization is not known. Here we identify an appressorium-like structure, which we call an expressorium that allows endophytic hyphae to penetrate the cuticle from the inside of the leaf to establish an epiphytic hyphal net on the surface of the leaf. We used a combination of scanning electron, transmission electron and confocal laser scanning microscopy to characterize this novel fungal structure and determine the composition of the hyphal cell wall using aniline blue and wheat germ agglutinin labelled with Alexafluor-488. Expressoria differentiate immediately below the cuticle in the leaf blade and leaf sheath intercalary cell division zones where the hyphae grow by tip growth. Differentiation of this structure requires components of both the NoxA and NoxB NADPH oxidase complexes. Major remodelling of the hyphal cell wall occurs following exit from the leaf. These results establish that the symbiotic association of E. festucae with L. perenne involves an interconnected hyphal network of both endophytic and epiphytic hyphae.
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Affiliation(s)
- Matthias Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Yvonne Becker
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- IGZ – Leibniz Institute of Vegetable and Ornamental Crops14979GroßbeerenGermany
| | - Kimberly Green
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
| | - Barry Scott
- Institute of Fundamental SciencesMassey UniversityPalmerston North4442New Zealand
- Bioprotection Research CentreMassey UniversityPalmerston North4442New Zealand
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28
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Dung JKS, Alderman SC, Walenta DL, Hamm PB. Spatial Patterns of Ergot and Quantification of Sclerotia in Perennial Ryegrass Seed Fields in Eastern Oregon. PLANT DISEASE 2016; 100:1110-1117. [PMID: 30682281 DOI: 10.1094/pdis-08-14-0787-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ergot, caused by Claviceps purpurea, is a major disease of perennial ryegrass grown for seed in eastern Oregon. The objective of this research was to quantify and describe the spatial patterns of ergot severity in each of three 50-ha commercial fields of perennial ryegrass grown for seed in 2012 and 2013. In total, 1,433 and 1,405 quadrats were sampled among the three fields in 2012 and 2013, respectively, and the percentage of quadrats with ergot ranged from 59 to 90%. The mean incidence of infected seed heads in each quadrat ranged between 13 and 29%, while mean severity in each quadrat ranged from 0.2 to 0.5 sclerotia per seed head. Significant autocorrelation and clustering were observed in all three fields in both years, as indicated by Moran's I and spatial analysis by distance indices of aggregation. The mean number of ergot sclerotia collected from each field after harvest ranged between 4 and 15 sclerotia m-2 in 2012 and 18 and 119 sclerotia m-2 in 2013. Sclerotia left in perennial fields after harvest are a significant source of inoculum that should be targeted for control. This is the first study to quantify spatial patterns of ergot in perennial ryegrass and provides insights into possible mechanisms that contribute to ergot etiology and epidemiology.
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Affiliation(s)
- Jeremiah K S Dung
- Department of Botany and Plant Pathology, Central Oregon Agricultural Research Center, Oregon State University, Madras
| | - Stephen C Alderman
- United States Department of Agriculture-Agricultural Research Service National Forage Seed Production Research Center, Corvallis, OR
| | - Darrin L Walenta
- Department of Crop and Soil Science, Union County Extension Center, LaGrande, OR
| | - Philip B Hamm
- Department of Botany and Plant Pathology, Hermiston Agricultural Research and Extension Center, Oregon State University, Hermiston
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29
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UvHOG1 is important for hyphal growth and stress responses in the rice false smut fungus Ustilaginoidea virens. Sci Rep 2016; 6:24824. [PMID: 27095476 PMCID: PMC4837404 DOI: 10.1038/srep24824] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/06/2016] [Indexed: 11/23/2022] Open
Abstract
Rice false smut caused by Ustilaginoidea virens is one of the most important diseases of rice worldwide. Although its genome has been sequenced, to date there is no report on targeted gene deletion in U. virens and no molecular studies on genetic mechanisms regulating the infection processes of this destructive pathogen. In this study, we attempted to generate knockout mutants of the ortholog of yeast HOG1 MAP kinase gene in U. virens. One Uvhog1 deletion mutant was identified after screening over 600 hygromycin-resistant transformants generated by Agrobacterium tumefaciens mediated transformation. The Uvhog1 mutant was reduced in growth rate and conidiation but had increased sensitivities to SDS, Congo red, and hyperosmotic stress. Deletion of UvHOG1 resulted in reduced expression of the stress response-related genes UvATF1 and UvSKN7. In the Uvhog1 mutant, NaCl treatment failed to stimulate the accumulation of sorbitol and glycerol. In addition, the Uvhog1 mutant had reduced toxicity on shoot growth in rice seed germination assays. Overall, as the first report of targeted gene deletion mutant in U. virens, our results showed that UvHOG1 likely has conserved roles in regulating stress responses, hyphal growth, and possibly secondary metabolism.
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30
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Gordon A, Basler R, Bansept-Basler P, Fanstone V, Harinarayan L, Grant PK, Birchmore R, Bayles RA, Boyd LA, O'Sullivan DM. The identification of QTL controlling ergot sclerotia size in hexaploid wheat implicates a role for the Rht dwarfing alleles. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2015; 128:2447-2460. [PMID: 26340982 DOI: 10.1007/s00122-015-2599-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 08/16/2015] [Indexed: 06/05/2023]
Abstract
Four QTL conferring resistance to ergot were identified in the UK winter wheat varieties 'Robigus' and 'Solstice'. Two QTL co-located with semi-dwarfing alleles at the Rht loci Rht - 1B and Rht - 1D implicating a role of these DELLA proteins in infection success of Claviceps purpurea. The fungal pathogen Claviceps purpurea infects ovaries of a broad range of temperate grasses and cereals, including hexaploid wheat, causing a disease commonly known as ergot. Sclerotia produced in place of seed carry a cocktail of harmful alkaloid compounds that result in a range of symptoms in humans and animals, causing ergotism. Following a field assessment of C. purpurea infection in winter wheat, two varieties 'Robigus' and 'Solstice' were selected which consistently produced the largest differential effect on ergot sclerotia weights. They were crossed to produce a doubled haploid mapping population, and a marker map, consisting of 714 genetic loci and a total length of 2895 cM was produced. Four ergot reducing QTL were identified using both sclerotia weight and size as phenotypic parameters; QCp.niab.2A and QCp.niab.4B being detected in the wheat variety 'Robigus', and QCp.niab.6A and QCp.niab.4D in the variety 'Solstice'. The ergot resistance QTL QCp.niab.4B and QCp.niab.4D peaks mapped to the same markers as the known reduced height (Rht) loci on chromosomes 4B and 4D, Rht-B1 and Rht-D1, respectively. In both cases, the reduction in sclerotia weight and size was associated with the semi-dwarfing alleles, Rht-B1b from 'Robigus' and Rht-D1b from 'Solstice'. Two-dimensional, two-QTL scans identified significant additive interactions between QTL QCp.niab.4B and QCp.niab.4D, and between QCp.niab.2A and QCp.niab.4B when looking at sclerotia size, but not between QCp.niab.2A and QCp.niab.4D. The two plant height QTL, QPh.niab.4B and QPh.niab.4D, which mapped to the same locations as QCp.niab.4B and QCp.niab.4D, also displayed significant genetic interactions.
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Affiliation(s)
- Anna Gordon
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK.
| | - Ryan Basler
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
| | - Pauline Bansept-Basler
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Syngenta France, Route de Moyencourt, 78910, Orgerus, France
| | | | - Lakshmi Harinarayan
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Bayer CropScience, Department Technologiepark 38, 9052, Ghent, Belgium
| | - Paul K Grant
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | | | - Rosemary A Bayles
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- Woodgate Farm, Cascob, Presteigne, Powys, LD8 2NT, UK
| | | | - Donal M O'Sullivan
- NIAB, Huntingdon Road, Cambridge, CB3 0LE, UK
- School of Agriculture, Policy and Development, University of Reading, Reading, RG6 6AR, UK
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31
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Strugala R, Delventhal R, Schaffrath U. An organ-specific view on non-host resistance. FRONTIERS IN PLANT SCIENCE 2015; 6:526. [PMID: 26257747 PMCID: PMC4507044 DOI: 10.3389/fpls.2015.00526] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 06/29/2015] [Indexed: 05/23/2023]
Abstract
Non-host resistance (NHR) is the resistance of plants to a plethora of non-adapted pathogens and is considered as one of the most robust resistance mechanisms of plants. Studies have shown that the efficiency of resistance in general and NHR in particular could vary in different plant organs, thus pointing to tissue-specific determinants. This was exemplified by research on host and non-host interactions of the fungal plant pathogen Magnaporthe oryzae with rice and Arabidopsis, respectively. Thus, rice roots were shown to be impaired in resistance to M. oryzae isolates to which leaves of the same rice cultivar are highly resistant. Moreover, roots of Arabidopsis are also accessible to penetration by M. oryzae while leaves of this non-host plant cannot be infected. We addressed the question whether or not other plant tissues such as the reproductive system also differ in NHR compared to leaves. Inoculation experiments on wheat with different Magnaporthe species forming either a host or non-host type of interaction revealed that NHR was as effective on spikes as on leaves. This finding might pave the way for combatting M. oryzae disease on wheat spikes which has become a serious threat especially in South America.
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Affiliation(s)
| | | | - Ulrich Schaffrath
- *Correspondence: Ulrich Schaffrath, RiBa-Lab, Department of Plant Physiology (Biology III), Rheinisch-Westfälische Technische Hochschule Aachen University, 52056 Aachen, Germany,
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32
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Fan J, Guo XY, Li L, Huang F, Sun WX, Li Y, Huang YY, Xu YJ, Shi J, Lei Y, Zheng AP, Wang WM. Infection of Ustilaginoidea virens intercepts rice seed formation but activates grain-filling-related genes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2015; 57:577-90. [PMID: 25319482 PMCID: PMC5024071 DOI: 10.1111/jipb.12299] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 10/14/2014] [Indexed: 05/04/2023]
Abstract
Rice false smut has become an increasingly serious disease in rice (Oryza sativa L.) production worldwide. The typical feature of this disease is that the fungal pathogen Ustilaginoidea virens (Uv) specifically infects rice flower and forms false smut ball, the ustiloxin-containing ball-like fungal colony, of which the size is usually several times larger than that of a mature rice seed. However, the underlying mechanisms of Uv-rice interaction are poorly understood. Here, we applied time-course microscopic and transcriptional approaches to investigate rice responses to Uv infection. The results demonstrated that the flower-opening process and expression of associated transcription factors, including ARF6 and ARF8, were inhibited in Uv-infected spikelets. The ovaries in infected spikelets were interrupted in fertilization and thus were unable to set seeds. However, a number of grain-filling-related genes, including seed storage protein genes, starch anabolism genes and endosperm-specific transcription factors (RISBZ1 and RPBF), were highly transcribed as if the ovaries were fertilized. In addition, critical defense-related genes like NPR1 and PR1 were downregulated by Uv infection. Our data imply that Uv may hijack host nutrient reservoir by activation of the grain-filling network because of growth and formation of false smut balls.
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Affiliation(s)
- Jing Fan
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Xiao-Yi Guo
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Liang Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Fu Huang
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wen-Xian Sun
- Department of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Yan Li
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yan-Yan Huang
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yong-Ju Xu
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Jun Shi
- College of Agronomy, Sichuan Agricultural University, Chengdu, 611130, China
| | - Yang Lei
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Ai-Ping Zheng
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
| | - Wen-Ming Wang
- Rice Research Institute, Sichuan Agricultural University, Chengdu, 611130, China
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33
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The key role of peltate glandular trichomes in symbiota comprising clavicipitaceous fungi of the genus periglandula and their host plants. Toxins (Basel) 2015; 7:1355-73. [PMID: 25894995 PMCID: PMC4417971 DOI: 10.3390/toxins7041355] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 03/27/2015] [Accepted: 04/01/2015] [Indexed: 01/07/2023] Open
Abstract
Clavicipitaceous fungi producing ergot alkaloids were recently discovered to be epibiotically associated with peltate glandular trichomes of Ipomoea asarifolia and Turbina corymbosa, dicotyledonous plants of the family Convolvulaceae. Mediators of the close association between fungi and trichomes may be sesquiterpenes, main components in the volatile oil of different convolvulaceous plants. Molecular biological studies and microscopic investigations led to the observation that the trichomes do not only secrete sesquiterpenes and palmitic acid but also seem to absorb ergot alkaloids from the epibiotic fungal species of the genus Periglandula. Thus, the trichomes are likely to have a dual and key function in a metabolic dialogue between fungus and host plant.
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34
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Hinsch J, Vrabka J, Oeser B, Novák O, Galuszka P, Tudzynski P. De novo biosynthesis of cytokinins in the biotrophic fungus Claviceps purpurea. Environ Microbiol 2015; 17:2935-51. [PMID: 25753486 DOI: 10.1111/1462-2920.12838] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 02/28/2015] [Indexed: 01/08/2023]
Abstract
Disease symptoms of some phytopathogenic fungi are associated with changes in cytokinin (CK) levels. Here, we show that the CK profile of ergot-infected rye plants is also altered, although no pronounced changes occur in the expression of the host plant's CK biosynthesis genes. Instead, we demonstrate a clearly different mechanism: we report on the first fungal de novo CK biosynthesis genes, prove their functions and constitute a biosynthetic pathway. The ergot fungus Claviceps purpurea produces substantial quantities of CKs in culture and, like plants, expresses enzymes containing the isopentenyltransferase and lonely guy domains necessary for de novo isopentenyladenine production. Uniquely, two of these domains are combined in one bifunctional enzyme, CpIPT-LOG, depicting a novel and potent mechanism for CK production. The fungus also forms trans-zeatin, a reaction catalysed by a CK-specific cytochrome P450 monooxygenase, which is encoded by cpp450 forming a small cluster with cpipt-log. Deletion of cpipt-log and cpp450 did not affect virulence of the fungus, but Δcpp450 mutants exhibit a hyper-sporulating phenotype, implying that CKs are environmental factors influencing fungal development.
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Affiliation(s)
- Janine Hinsch
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-University Münster, Schlossplatz 8, 48143, Münster, Germany
| | - Josef Vrabka
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, 78371, Olomouc, Czech Republic
| | - Birgitt Oeser
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-University Münster, Schlossplatz 8, 48143, Münster, Germany
| | - Ondřej Novák
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, 78371, Olomouc, Czech Republic
| | - Petr Galuszka
- Centre of the Region Haná for Biotechnological and Agricultural Research, Palacký University & Institute of Experimental Botany AS CR, Šlechtitelů 11, 78371, Olomouc, Czech Republic
| | - Paul Tudzynski
- Institute of Plant Biology and Biotechnology, Westfälische Wilhelms-University Münster, Schlossplatz 8, 48143, Münster, Germany
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Thamhesl M, Apfelthaler E, Schwartz-Zimmermann HE, Kunz-Vekiru E, Krska R, Kneifel W, Schatzmayr G, Moll WD. Rhodococcus erythropolis MTHt3 biotransforms ergopeptines to lysergic acid. BMC Microbiol 2015; 15:73. [PMID: 25887091 PMCID: PMC4411749 DOI: 10.1186/s12866-015-0407-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 03/11/2015] [Indexed: 12/04/2022] Open
Abstract
Background Ergopeptines are a predominant class of ergot alkaloids produced by tall fescue grass endophyte Neotyphodium coenophialum or cereal pathogen Claviceps purpurea. The vasoconstrictive activity of ergopeptines makes them toxic for mammals, and they can be a problem in animal husbandry. Results We isolated an ergopeptine degrading bacterial strain, MTHt3, and classified it, based on its 16S rDNA sequence, as a strain of Rhodococcus erythropolis (Nocardiaceae, Actinobacteria). For strain isolation, mixed microbial cultures were obtained from artificially ergot alkaloid-enriched soil, and provided with the ergopeptine ergotamine in mineral medium for enrichment. Individual colonies derived from such mixed cultures were screened for ergotamine degradation by high performance liquid chromatography and fluorescence detection. R. erythropolis MTHt3 converted ergotamine to ergine (lysergic acid amide) and further to lysergic acid, which accumulated as an end product. No other tested R. erythropolis strain degraded ergotamine. R. erythropolis MTHt3 degraded all ergopeptines found in an ergot extract, namely ergotamine, ergovaline, ergocristine, ergocryptine, ergocornine, and ergosine, but the simpler lysergic acid derivatives agroclavine, chanoclavine, and ergometrine were not degraded. Temperature and pH dependence of ergotamine and ergine bioconversion activity was different for the two reactions. Conclusions Degradation of ergopeptines to ergine is a previously unknown microbial reaction. The reaction end product, lysergic acid, has no or much lower vasoconstrictive activity than ergopeptines. If the genes encoding enzymes for ergopeptine catabolism can be cloned and expressed in recombinant hosts, application of ergopeptine and ergine degrading enzymes for reduction of toxicity of ergot alkaloid-contaminated animal feed may be feasible.
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Affiliation(s)
| | - Elisabeth Apfelthaler
- Department for Agrobiotechnology (IFA-Tulln), Christian Doppler Laboratory for Mycotoxin Research, Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU) Vienna, Konrad Lorenz Straße 20, 3430, Tulln, Austria.
| | - Heidi Elisabeth Schwartz-Zimmermann
- Department for Agrobiotechnology (IFA-Tulln), Christian Doppler Laboratory for Mycotoxin Research, Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU) Vienna, Konrad Lorenz Straße 20, 3430, Tulln, Austria.
| | - Elisavet Kunz-Vekiru
- Department for Agrobiotechnology (IFA-Tulln), Christian Doppler Laboratory for Mycotoxin Research, Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU) Vienna, Konrad Lorenz Straße 20, 3430, Tulln, Austria.
| | - Rudolf Krska
- Department for Agrobiotechnology (IFA-Tulln), Christian Doppler Laboratory for Mycotoxin Research, Center for Analytical Chemistry, University of Natural Resources and Life Sciences (BOKU) Vienna, Konrad Lorenz Straße 20, 3430, Tulln, Austria.
| | - Wolfgang Kneifel
- Christian Doppler Laboratory for Innovative Bran Biorefinery, University of Natural Resources and Life Sciences, Muthgasse 18, 1190, Vienna, Austria.
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Dorn-In S, Fahn C, Hölzel CS, Wenz S, Hartwig I, Schwaiger K, Bauer J. Reconstruction of the original mycoflora in pelleted feed by PCR-SSCP and qPCR. FEMS Microbiol Lett 2014; 359:182-92. [PMID: 25088501 DOI: 10.1111/1574-6968.12552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/30/2014] [Accepted: 07/30/2014] [Indexed: 11/28/2022] Open
Abstract
Ground feeds for pigs were investigated for fungal contamination before and after pelleting (subsamples in total n = 24) by cultural and molecular biological methods. A fungal-specific primer pair ITS1/ITS5.8R was used to amplify fungal DNA; PCR products were processed for the PCR-SSCP method. In the resulting acrylamide gel, more than 85% of DNA bands of ground feeds were preserved after pelleting. Twenty-two DNA bands were sequenced; all represented fungal DNA. The level of fungal DNA in ground feed samples was equivalent to 4.77-5.69 log10 CFU g(-1) , calculated by qPCR using a standard curve of Aspergillus flavus. In pelleted feed, the level of fungal DNA was in average ± 0.07 log10 different from ground feed. Quantified by cultural methods, the fresh ground feeds contained up to 4.51 log10 CFU g(-1) culturable fungi, while there was < 2.83 log10 CFU g(-1) detected in pelleted feeds. This result shows that, while the process of pelleting reduced the amount of living fungi dramatically, it did not affect the total fungal DNA in feed. Thus, the described methodology was able to reconstruct the fungal microbiota in feeds and reflected a considerable fungal contamination of raw materials such as grains.
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Abstract
An update on new developments in the field of ergot alkaloid biosynthesis since 2011 is highlighted.
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Affiliation(s)
- Dorota Jakubczyk
- The John Innes Centre
- Department of Biological Chemistry
- Norwich NR4 7UH, UK
| | - Johnathan Z. Cheng
- The John Innes Centre
- Department of Biological Chemistry
- Norwich NR4 7UH, UK
| | - Sarah E. O'Connor
- The John Innes Centre
- Department of Biological Chemistry
- Norwich NR4 7UH, UK
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Wäli PP, Wäli PR, Saikkonen K, Tuomi J. Is the pathogenic ergot fungus a conditional defensive mutualist for its host grass? PLoS One 2013; 8:e69249. [PMID: 23874924 PMCID: PMC3707848 DOI: 10.1371/journal.pone.0069249] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 06/11/2013] [Indexed: 11/26/2022] Open
Abstract
It is well recognized, that outcomes of mutualistic plant-microorganism interactions are often context dependent and can range from mutualistic to antagonistic depending on conditions. Instead, seemingly pathogenic associations are generally considered only harmful to plants. The ergot fungus (Claviceps purpurea) is a common seed pathogen of grasses and cereals. Ergot sclerotia contain alkaloids which can cause severe toxicity in mammals when ingested, and thus the fungal infection might provide protection for the host plant against mammalian herbivores. Theoretically, the net effect of ergot infection would positively affect host seed set if the cost is not too high and the defensive effect is strong enough. According to our empirical data, this situation is plausible. First, we found no statistically significant seed loss in wild red fescue (Festuca rubra) inflorescences due to ergot infection, but the seed succession decreased along increasing number of sclerotia. Second, in a food choice experiment, sheep showed avoidance against forage containing ergot. Third, the frequency of ergot-infected inflorescences was higher in sheep pastures than surrounding ungrazed areas, indicating a protective effect against mammalian grazing. We conclude that, although ergot can primarily be categorized as a plant pathogen, ergot infection may sometimes represent indirect beneficial effects for the host plant. Ergot may thus serve as a conditional defensive mutualist for its host grass, and the pathogenic interaction may range from antagonistic to mutualistic depending on the situation.
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Hulvová H, Galuszka P, Frébortová J, Frébort I. Parasitic fungus Claviceps as a source for biotechnological production of ergot alkaloids. Biotechnol Adv 2013; 31:79-89. [DOI: 10.1016/j.biotechadv.2012.01.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 12/21/2011] [Accepted: 01/05/2012] [Indexed: 01/03/2023]
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Comparison of Claviceps purpurea populations originated from experimental plots or fields of rye. Open Life Sci 2012. [DOI: 10.2478/s11535-012-0075-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Abstract
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Ergoline alkaloids in convolvulaceous host plants originate from epibiotic clavicipitaceous fungi of the genus Periglandula. FUNGAL ECOL 2012. [DOI: 10.1016/j.funeco.2011.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Scott B, Becker Y, Becker M, Cartwright G. Morphogenesis, Growth, and Development of the Grass Symbiont Epichlöe festucae. TOPICS IN CURRENT GENETICS 2012. [DOI: 10.1007/978-3-642-22916-9_12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Affiliation(s)
- Francine Govers
- Laboratory of Phytopathology, Wageningen University, 1-6708 PB Wageningen, Netherlands
- Centre for BioSystems Genomics (CBSG), 98-6700 AB Wageningen, Netherlands
| | - Gerco C. Angenent
- Laboratory of Molecular Biology, Wageningen University, 1-6708 PB Wageningen, Netherlands
- Business Unit Bioscience, Plant Research International, 16-6700 AA Wageningen, Netherlands
- Centre for BioSystems Genomics (CBSG), 98-6700 AB Wageningen, Netherlands
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Deletion of Mid1, a putative stretch-activated calcium channel in Claviceps purpurea, affects vegetative growth, cell wall synthesis and virulence. Microbiology (Reading) 2009; 155:3922-3933. [DOI: 10.1099/mic.0.030825-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The putative Claviceps purpurea homologue of the Saccharomyces cerevisiae stretch-activated calcium ion channel Mid1 was investigated for its role in vegetative growth, differentiation and pathogenicity on rye (Secale cereale). Gene replacement mutants of Cl. purpurea mid1 were not affected in polar growth and branching in axenic culture but showed a significantly reduced growth rate. The growth defect could not be complemented by Ca2+ supplementation, in contrast to mid1 mutants in yeast, but the altered sensitivity of the mutants to changes in external and internal Ca2+ concentrations indicates some role of Mid1 in Ca2+ homeostasis. The major effect of mid1 deletion, however, was the complete loss of virulence: infected rye plants showed no disease symptoms at all. Detailed analyses of in vitro-infected rye ovaries demonstrated that the Δmid1 mutants had multiple apical branches and were unable to infect the host tissue, suggesting that Mid1 is essential for generating the necessary mechanical force for penetration. This is believed to be the first report of an essential role for a Mid1 homologue in the virulence of a plant-pathogenic fungus.
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Oeser B, Beaussart F, Haarmann T, Lorenz N, Nathues E, Rolke Y, Scheffer J, Weiner J, Tudzynski P. Expressed sequence tags from the flower pathogen Claviceps purpurea. MOLECULAR PLANT PATHOLOGY 2009; 10:665-84. [PMID: 19694956 PMCID: PMC6640482 DOI: 10.1111/j.1364-3703.2009.00560.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
SUMMARY The ascomycete Claviceps purpurea (ergot) is a biotrophic flower pathogen of rye and other grasses. The deleterious toxic effects of infected rye seeds on humans and grazing animals have been known since the Middle Ages. To gain further insight into the molecular basis of this disease, we generated about 10 000 expressed sequence tags (ESTs)-about 25% originating from axenic fungal culture and about 75% from tissues collected 6-20 days after infection of rye spikes. The pattern of axenic vs. in planta gene expression was compared. About 200 putative plant genes were identified within the in planta library. A high percentage of these were predicted to function in plant defence against the ergot fungus and other pathogens, for example pathogenesis-related proteins. Potential fungal pathogenicity and virulence genes were found via comparison with the pathogen-host interaction database (PHI-base; http://www.phi-base.org) and with genes known to be highly expressed in the haustoria of the bean rust fungus. Comparative analysis of Claviceps and two other fungal flower pathogens (necrotrophic Fusarium graminearum and biotrophic Ustilago maydis) highlighted similarities and differences in their lifestyles, for example all three fungi have signalling components and cell wall-degrading enzymes in their arsenal. In summary, the analysis of axenic and in planta ESTs yielded a collection of candidate genes to be evaluated for functional roles in this plant-microbe interaction.
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Affiliation(s)
- Birgitt Oeser
- Institut für Botanik, Westf. Wilhelms Universität Münster, Schlossgarten 3, D 48149 Münster, Germany.
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Giesbert S, Schürg T, Scheele S, Tudzynski P. The NADPH oxidase Cpnox1 is required for full pathogenicity of the ergot fungus Claviceps purpurea. MOLECULAR PLANT PATHOLOGY 2008; 9:317-27. [PMID: 18705873 PMCID: PMC6640299 DOI: 10.1111/j.1364-3703.2008.00466.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The role of reactive oxygen species (ROS) in interactions between phytopathogenic fungi and their hosts is well established. An oxidative burst mainly caused by superoxide formation by membrane-associated NADPH oxidases is an essential element of plant defence reactions. Apart from primary effects, ROS play a major role as a second messenger in host response. Recently, NADPH oxidase (nox)-encoding genes have been identified in filamentous fungi. Functional analyses have shown that these fungal enzymes are involved in sexual differentiation, and there is growing evidence that they also affect developmental programmes involved in fungus-plant interactions. Here we show that in the biotrophic plant pathogen Claviceps purpurea deletion of the cpnox1 gene, probably encoding an NADPH oxidase, has impact on germination of conidia and pathogenicity: Deltacpnox1 mutants can penetrate the host epidermis, but they are impaired in colonization of the plant ovarian tissue. In the few cases where macroscopic signs of infection (honeydew) appear, they are extremely delayed and fully developed sclerotia have never been observed. C. purpurea Nox1 is important for the interaction with its host, probably by directly affecting pathogenic differentiation of the fungus.
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Affiliation(s)
- Sabine Giesbert
- Institut für Botanik, Westf. Wilhelms-Universität, Schlossgarten 3, D-48149 Münster, Germany
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Douhan GW, Smith ME, Huyrn KL, Westbrook A, Beerli P, Fisher AJ. Multigene analysis suggests ecological speciation in the fungal pathogen Claviceps purpurea. Mol Ecol 2008; 17:2276-86. [PMID: 18373531 PMCID: PMC2443689 DOI: 10.1111/j.1365-294x.2008.03753.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Claviceps purpurea is an important pathogen of grasses and source of novel chemical compounds. Three groups within this species (G1, G2 and G3) have been recognized based on habitat association, sclerotia and conidia morphology, as well as alkaloid production. These groups have further been supported by Random Amplification of Polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) markers, suggesting this species may be more accurately described as a species complex. However, all divergent ecotypes can coexist in sympatric populations with no obvious physical barriers to prevent gene flow. In this study, we used both phylogenetic and population genetic analyses to test for speciation within C. purpurea using DNA sequences from ITS, a RAS-like locus, and a portion of beta-tubulin. The G1 types are significantly divergent from the G2/G3 types based on each of the three loci and the combined dataset, whereas the G2/G3 types are more integrated with one another. Although the G2 and G3 lineages have not diverged as much as the G1 lineage based on DNA sequence data, the use of three DNA loci does reliably separate the G2 and G3 lineages. However, the population genetic analyses strongly suggest little to no gene flow occurring between the different ecotypes, and we argue that this process is driven by adaptations to ecological habitats; G1 isolates are associated with terrestrial grasses, G2 isolates are found in wet and shady environments, and G3 isolates are found in salt marsh habitats.
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Affiliation(s)
- G W Douhan
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA.
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Rolke Y, Tudzynski P. The small GTPase Rac and the p21-activated kinase Cla4 in Claviceps purpurea: interaction and impact on polarity, development and pathogenicity. Mol Microbiol 2008; 68:405-23. [PMID: 18284596 DOI: 10.1111/j.1365-2958.2008.06159.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Claviceps purpurea, the ergot fungus, is a highly specialized pathogen of grasses; its colonization of host ovarian tissue requires an extended period of strictly polarized, oriented growth towards the vascular tissue. To understand this process, we study the role of signalling factors affecting polarity and differentiation. We showed that the small GTPase Cdc42 is involved in polarity, sporulation and in planta growth in C. purpurea. Here we present evidence that the GTPase Rac has an even stronger and, in some aspects, inverse impact on growth and development: Deltarac mutants form coralline-like colonies, show hyper-branching, loss of polarity, sporulation and ability to penetrate. Functional analyses and yeast two-hybrid studies prove that the p21-activated kinase Cla4 is a major downstream partner of Rac. Phosphorylation assays of MAP kinases and expression studies of genes encoding reactive oxygen species (ROS)-scavenging and -generating enzymes indicate a function of Rac and Cla4 in fungal ROS homoeostasis which could contribute to their drastic impact on differentiation.
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Affiliation(s)
- Yvonne Rolke
- Institut für Botanik, Westf. Wilhelms-Universität Münster, Schlossgarten 3, D-48149 Münster, Germany
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Sclerotial development in Sclerotinia sclerotiorum: awakening molecular analysis of a “Dormant” structure. FUNGAL BIOL REV 2008. [DOI: 10.1016/j.fbr.2007.10.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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