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Šigutová H, Pyszko P, Šigut M, Czajová K, Kostovčík M, Kolařík M, Hařovská D, Drozd P. Concentration-dependent effect of plant secondary metabolites on bacterial and fungal microbiomes in caterpillar guts. Microbiol Spectr 2024; 12:e0299423. [PMID: 37991377 PMCID: PMC10783044 DOI: 10.1128/spectrum.02994-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 10/16/2023] [Indexed: 11/23/2023] Open
Abstract
IMPORTANCE The caterpillar gut is an excellent model system for studying host-microbiome interactions, as it represents an extreme environment for microbial life that usually has low diversity and considerable variability in community composition. Our study design combines feeding caterpillars on a natural and artificial diet with controlled levels of plant secondary metabolites and uses metabarcoding and quantitative PCR to simultaneously profile bacterial and fungal assemblages, which has never been performed. Moreover, we focus on multiple caterpillar species and consider diet breadth. Contrary to many previous studies, our study suggested the functional importance of certain microbial taxa, especially bacteria, and confirmed the previously proposed lower importance of fungi for caterpillar holobiont. Our study revealed the lack of differences between monophagous and polyphagous species in the responses of microbial assemblages to plant secondary metabolites, suggesting the limited role of the microbiome in the plasticity of the herbivore diet.
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Affiliation(s)
- Hana Šigutová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Department of Zoology, Faculty of Science, Palacký University, Olomouc, Czechia
| | - Petr Pyszko
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Martin Šigut
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Kateřina Czajová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
| | - Martin Kostovčík
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Miroslav Kolařík
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Denisa Hařovská
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Prague, Czechia
| | - Pavel Drozd
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czechia
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2
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Lee S, Völz R, Lim YJ, Harris W, Kim S, Lee YH. The nuclear effector MoHTR3 of Magnaporthe oryzae modulates host defence signalling in the biotrophic stage of rice infection. MOLECULAR PLANT PATHOLOGY 2023; 24:602-615. [PMID: 36977203 DOI: 10.1111/mpp.13326] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/07/2023] [Accepted: 02/28/2023] [Indexed: 05/18/2023]
Abstract
Fungal effectors play a pivotal role in suppressing the host defence system, and their evolution is highly dynamic. By comparative sequence analysis of plant-pathogenic fungi and Magnaporthe oryzae, we identified the small secreted C2 H2 zinc finger protein MoHTR3. MoHTR3 exhibited high conservation in M. oryzae strains but low conservation among other plant-pathogenic fungi, suggesting an emerging evolutionary selection process. MoHTR3 is exclusively expressed in the biotrophic stage of fungal invasion, and the encoded protein localizes to the biotrophic interfacial complex (BIC) and the host cell nucleus. The signal peptide crucial for MoHTR3' secretion to the BIC and the protein section required for its translocation to the nucleus were both identified by a functional protein domain study. The host-nuclear localization of MoHTR3 suggests a function as a transcriptional modulator of host defence gene induction. After ΔMohtr3 infection, the expression of jasmonic acid- and ethylene-associated genes was diminished in rice, in contrast to when the MoHTR3-overexpressing strain (MoHTR3ox) was applied. The transcript levels of salicylic acid- and defence-related genes were also affected after ΔMohtr3 and MoHTR3ox application. In pathogenicity assays, ΔMohtr3 was indistinguishable from the wild type. However, MoHTR3ox-infected plants showed diminished lesion formation and hydrogen peroxide accumulation, accompanied by a decrease in susceptibility, suggesting that the MoHTR3-induced manipulation of host cells affects host-pathogen interaction. MoHTR3 emphasizes the role of the host nucleus as a critical target for the pathogen-driven manipulation of host defence mechanisms and underscores the ongoing evolution of rice blast's arms race.
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Affiliation(s)
- Sehee Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Ronny Völz
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - You-Jin Lim
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
| | - William Harris
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Seongbeom Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
| | - Yong-Hwan Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, South Korea
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea
- Center for Fungal Genetic Resources, Seoul National University, Seoul, South Korea
- Plant Immunity Research Center, Seoul National University, Seoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
- Center for Plant Microbiome Research, Seoul National University, Seoul, South Korea
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3
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Lignin-Modifying Enzymes in Scedosporium Species. J Fungi (Basel) 2023; 9:jof9010105. [PMID: 36675925 PMCID: PMC9861984 DOI: 10.3390/jof9010105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
Scedosporium species are usually soil saprophytes but some members of the genus such as S. apiospermum and S. aurantiacum have been regularly reported as causing human respiratory infections, particularly in patients with cystic fibrosis (CF). Because of their low sensitivity to almost all available antifungal drugs, a better understanding of the pathogenic mechanisms of these fungi is mandatory. Likewise, identification of the origin of the contamination of patients with CF may be helpful to propose prophylactic measures. In this aim, environmental studies were conducted demonstrating that Scedosporium species are abundant in human-made environments and associated with nutrient-rich substrates. Although their natural habitat remains unknown, there is accumulated evidence to consider them as wood-decaying fungi. This study aimed to demonstrate the ability of these fungi to utilize lignocellulose compounds, especially lignin, as a carbon source. First, the lignolytic properties of Scedosporium species were confirmed by cultural methods, and biochemical assays suggested the involvement of peroxidases and oxidases as lignin-modifying enzymes. Scedosporium genomes were then screened using tBLASTn searches. Fifteen candidate genes were identified, including four peroxidase and seven oxidase genes, and some of them were shown, by real-time PCR experiments, to be overexpressed in lignin-containing medium, thus confirming their involvement in lignin degradation.
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Syrova DS, Shaposhnikov AI, Yuzikhin OS, Belimov AA. Destruction and Transformation of Phytohormones By Microorganisms. APPL BIOCHEM MICRO+ 2022. [DOI: 10.1134/s0003683822010094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Yow AG, Zhang Y, Bansal K, Eacker SM, Sullivan S, Liachko I, Cubeta MA, Rollins JA, Ashrafi H. Genome sequence of Monilinia vaccinii-corymbosi sheds light on mummy berry disease infection of blueberry and mating type. G3-GENES GENOMES GENETICS 2021; 11:6062400. [PMID: 33598705 PMCID: PMC8022979 DOI: 10.1093/g3journal/jkaa052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 10/29/2020] [Indexed: 11/22/2022]
Abstract
Mummy berry disease, caused by the fungal pathogen Monilinia vaccinii-corymbosi (Mvc), is one of the most economically important diseases of blueberries in North America. Mvc is capable of inducing two separate blighting stages during its life cycle. Infected fruits are rendered mummified and unmarketable. Genomic data for this pathogen is lacking, but could be useful in understanding the reproductive biology of Mvc and the mechanisms it deploys to facilitate host infection. In this study, PacBio sequencing and Hi-C interaction data were utilized to create a chromosome-scale reference genome for Mvc. The genome comprises nine chromosomes with a total length of 30 Mb, an N50 length of 4.06 Mb, and an average 413X sequence coverage. A total of 9399 gene models were predicted and annotated, and BUSCO analysis revealed that 98% of 1,438 searched conserved eukaryotic genes were present in the predicted gene set. Potential effectors were identified, and the mating-type (MAT) locus was characterized. Biotrophic effectors allow the pathogen to avoid recognition by the host plant and evade or mitigate host defense responses during the early stages of fruit infection. Following locule colonization, necrotizing effectors promote the mummification of host tissues. Potential biotrophic effectors utilized by Mvc include chorismate mutase for reducing host salicylate and necrotrophic effectors include necrosis-inducing proteins and hydrolytic enzymes for macerating host tissue. The MAT locus sequences indicate the potential for homothallism in the reference genome, but a deletion allele of the MAT locus, characterized in a second isolate, indicates heterothallism. Further research is needed to verify the roles of individual effectors in virulence and to determine the role of the MAT locus in outcrossing and population genotypic diversity.
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Affiliation(s)
- Ashley G Yow
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695, USA
| | - Yucheng Zhang
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Kamaldeep Bansal
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | | | | | | | - Marc A Cubeta
- Department of Entomology and Plant Pathology, Center for Integrated Fungal Research, North Carolina State University, Raleigh, NC 27606, USA
| | - Jeffrey A Rollins
- Department of Plant Pathology, University of Florida, Gainesville, FL 32611, USA
| | - Hamid Ashrafi
- Department of Horticultural Science, North Carolina State University, Raleigh, NC 27695, USA
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Poirier W, Ravenel K, Bouchara JP, Giraud S. Lower Funneling Pathways in Scedosporium Species. Front Microbiol 2021; 12:630753. [PMID: 34276578 PMCID: PMC8283699 DOI: 10.3389/fmicb.2021.630753] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 06/10/2021] [Indexed: 11/17/2022] Open
Abstract
Lignin, a natural polyaromatic macromolecule, represents an essential component of the lignocellulose biomass. Due to its complexity, the natural degradation of this molecule by microorganisms still remains largely misunderstood. Extracellular oxidative degradation is followed by intracellular metabolic degradation of conserved aromatic intermediate compounds (protocatechuate, catechol, hydroxyquinol, and gentisic acid) that are used as carbon and energy sources. The lower funneling pathways are characterized by the opening of the aromatic ring of these molecules through dioxygenases, leading to degradation products that finally enter into the tricarboxylic acid (TCA) cycle. In order to better understand the adaptation mechanisms of Scedosporium species to their environment, these specific catabolism pathways were studied. Genes encoding ring-cleaving dioxygenases were identified in Scedosporium genomes by sequence homology, and a bioinformatic analysis of the organization of the corresponding gene clusters was performed. In addition, these predictions were confirmed by evaluation of the expression level of the genes of the gentisic acid cluster. When the fungus was cultivated in the presence of lignin or gentisic acid as sole carbon source, experiments revealed that the genes of the gentisic acid cluster were markedly overexpressed in the two Scedosporium species analyzed (Scedosporium apiospermum and Scedosporium aurantiacum). Only the gene encoding a membrane transporter was not overexpressed in the gentisic acid-containing medium. Together, these data suggest the involvement of the lower funneling pathways in Scedosporium adaptation to their environment.
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Affiliation(s)
- Wilfried Poirier
- UNIV Angers, UNIV Brest, Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), SFR ICAT, Angers, France
| | - Kevin Ravenel
- UNIV Angers, UNIV Brest, Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), SFR ICAT, Angers, France
| | - Jean-Philippe Bouchara
- UNIV Angers, UNIV Brest, Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), SFR ICAT, Angers, France
| | - Sandrine Giraud
- UNIV Angers, UNIV Brest, Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP), SFR ICAT, Angers, France
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7
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Martins TM, Martins C, Silva Pereira C. Multiple degrees of separation in the central pathways of the catabolism of aromatic compounds in fungi belonging to the Dikarya sub-Kingdom. Adv Microb Physiol 2019; 75:177-203. [PMID: 31655737 DOI: 10.1016/bs.ampbs.2019.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The diversity and abundance of aromatic compounds in nature is crucial for proper metabolism in all biological systems, and also impacts greatly the development of many industrial processes. Naturally, understanding their catabolism becomes fundamental for many scientific fields of research, from clinical and environmental to technological. The genetic basis of the central pathways for the catabolism of aromatic compounds in fungi, particularly of benzene derivatives, remains however poorly understood largely overlooking their significance. In some Dikarya species the genes of the central pathways are clustered in the genome, often in an array with peripheral pathway genes, even if the existence of a specific pathway does not necessarily mean that the composing genes are clustered. The current availability of many annotated fungal genomes in the postgenomic era creates conditions to reach a more holistic view of these processes through target analysis of the central pathways gene clusters. Inspired by this, we have critically analyzed the established biochemical and genetic data on the catabolism of aromatic compounds in Dikarya after dissecting the presence and distribution of central catabolic gene clusters (at times including also details on gene diversity, order and orientation) and of peripheral genes. Our methodological approach illustrates the multiple degrees of separation in these central pathways gene clusters across Dikarya. Surprisingly, they show a great degree of similarity irrespectively of the Dikarya division, emphasizing that knowledge established on either phyla can guide the identification of clusters of comparable composition (in-cluster plus peripheral genes) in uncharacterized species.
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Affiliation(s)
- Tiago M Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, Oeiras, Portugal
| | - Celso Martins
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, Oeiras, Portugal
| | - Cristina Silva Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa (ITQB NOVA), Av. da República, Oeiras, Portugal
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8
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Lubbers RJM, Dilokpimol A, Visser J, Mäkelä MR, Hildén KS, de Vries RP. A comparison between the homocyclic aromatic metabolic pathways from plant-derived compounds by bacteria and fungi. Biotechnol Adv 2019; 37:107396. [PMID: 31075306 DOI: 10.1016/j.biotechadv.2019.05.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 04/18/2019] [Accepted: 05/03/2019] [Indexed: 12/13/2022]
Abstract
Aromatic compounds derived from lignin are of great interest for renewable biotechnical applications. They can serve in many industries e.g. as biochemical building blocks for bioplastics or biofuels, or as antioxidants, flavor agents or food preservatives. In nature, lignin is degraded by microorganisms, which results in the release of homocyclic aromatic compounds. Homocyclic aromatic compounds can also be linked to polysaccharides, tannins and even found freely in plant biomass. As these compounds are often toxic to microbes already at low concentrations, they need to be degraded or converted to less toxic forms. Prior to ring cleavage, the plant- and lignin-derived aromatic compounds are converted to seven central ring-fission intermediates, i.e. catechol, protocatechuic acid, hydroxyquinol, hydroquinone, gentisic acid, gallic acid and pyrogallol through complex aromatic metabolic pathways and used as energy source in the tricarboxylic acid cycle. Over the decades, bacterial aromatic metabolism has been described in great detail. However, the studies on fungal aromatic pathways are scattered over different pathways and species, complicating a comprehensive view of fungal aromatic metabolism. In this review, we depicted the similarities and differences of the reported aromatic metabolic pathways in fungi and bacteria. Although both microorganisms share the main conversion routes, many alternative pathways are observed in fungi. Understanding the microbial aromatic metabolic pathways could lead to metabolic engineering for strain improvement and promote valorization of lignin and related aromatic compounds.
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Affiliation(s)
- Ronnie J M Lubbers
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
| | - Adiphol Dilokpimol
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
| | - Jaap Visser
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands.
| | - Miia R Mäkelä
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, Finland.
| | - Kristiina S Hildén
- Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, Finland.
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Department of Microbiology, University of Helsinki, Viikinkaari 9, Helsinki, Finland.
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9
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Westrick NM, Ranjan A, Jain S, Grau CR, Smith DL, Kabbage M. Gene regulation of Sclerotinia sclerotiorum during infection of Glycine max: on the road to pathogenesis. BMC Genomics 2019; 20:157. [PMID: 30808300 PMCID: PMC6390599 DOI: 10.1186/s12864-019-5517-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 02/07/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sclerotinia sclerotiorum is a broad-host range necrotrophic pathogen which is the causative agent of Sclerotinia stem rot (SSR), and a major disease of soybean (Glycine max). A time course transcriptomic analysis was performed in both compatible and incompatible soybean lines to identify pathogenicity and developmental factors utilized by S. sclerotiorum to achieve pathogenic success. RESULTS A comparison of genes expressed during early infection identified the potential importance of toxin efflux and nitrogen metabolism during the early stages of disease establishment. The later stages of infection were characterized by an apparent shift to survival structure formation. Analysis of genes highly upregulated in-planta revealed a temporal regulation of hydrolytic and detoxification enzymes, putative secreted effectors, and secondary metabolite synthesis genes. Redox regulation also appears to play a key role during the course of infection, as suggested by the high expression of genes involved in reactive oxygen species production and scavenging. Finally, distinct differences in early gene expression were noted based on the comparison of S. sclerotiorum infection of resistant and susceptible soybean lines. CONCLUSIONS Although many potential virulence factors have been noted in the S. sclerotiorum pathosystem, this study serves to highlight soybean specific processes most likely to be critical in successful infection. Functional studies of genes identified in this work are needed to confirm their importance to disease development, and may constitute valuable targets of RNAi approaches to improve resistance to SSR.
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Affiliation(s)
| | - Ashish Ranjan
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI USA
| | - Sachin Jain
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI USA
| | - Craig R. Grau
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI USA
| | - Damon L. Smith
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI USA
| | - Mehdi Kabbage
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI USA
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Salicylic acid as an effective elicitor for improved taxol production in endophytic fungus Pestalotiopsis microspora. PLoS One 2019; 14:e0212736. [PMID: 30794656 PMCID: PMC6386501 DOI: 10.1371/journal.pone.0212736] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 02/10/2019] [Indexed: 01/23/2023] Open
Abstract
Salicylic acid (SA) is an effective elicitor to increase taxol production in Pestalotiopsis microspora. Addition of SA at the concentration of 300 μM yielded taxol 625.47 μg L-1, 45- fold higher than that of the control. Elicitation of the role of SA in the fungal taxol biosynthetic pathway revealed that SA enhanced reactive oxygen species and lipid peroxidation of unsaturated fatty acids of P. microspora mycelia. This oxidative process stimulates isoprene biosynthetic pathway by triggering expression of the geranylgeranyl pyrophosphate synthase gene leading to improved biosynthesis of taxol in P. microspora.
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Hao G, Naumann TA, Vaughan MM, McCormick S, Usgaard T, Kelly A, Ward TJ. Characterization of a Fusarium graminearum Salicylate Hydroxylase. Front Microbiol 2019; 9:3219. [PMID: 30671040 PMCID: PMC6331432 DOI: 10.3389/fmicb.2018.03219] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Salicylic acid (SA) plays an important role in regulating plant defense responses against pathogens. However, pathogens have evolved ways to manipulate plant SA-mediated defense signaling. Fusarium graminearum causes Fusarium head blight (FHB) and reduces crop yields and quality by producing various mycotoxins. In this study, we aimed to identify the salicylate hydroxylase in F. graminearum and determine its role in wheat head blight development. We initially identified a gene in F. graminearum strain NRRL 46422 that encodes a putative salicylate hydroxylase (designated FgShyC). However, the FgShyC deletion mutant showed a similar ability to degrade SA as wild-type strain 46422; nor did overexpression of FgShyC in E. coli convert SA to catechol. The results indicate that FgShyC is not involved in SA degradation. Further genome sequence analyses resulted in the identification of eight salicylate hydroxylase candidates. Upon addition of 1 mM SA, FGSG_03657 (designated FgShy1), was induced approximately 400-fold. Heterologous expression of FgShy1 in E. coli converted SA to catechol, confirming that FgShy1 is a salicylate hydroxylase. Deletion mutants of FgShy1 were greatly impaired but not completely blocked in SA degradation. Expression analyses of infected tissue showed that FgShy1 was induced during infection, but virulence assays revealed that deletion of FgShy1 alone was not sufficient to affect FHB severity. Although the Fgshy1 deletion mutant did not reduce pathogenicity, we cannot rule out that additional salicylate hydroxylases are present in F. graminearum and characterization of these enzymes will be necessary to fully understand the role of SA-degradation in FHB pathogenesis.
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Affiliation(s)
- Guixia Hao
- Mycotoxin Prevention and Applied Microbiology Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture – Agricultural Research Service, Peoria, IL, United States
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12
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Rocheleau H, Al-Harthi R, Ouellet T. Degradation of salicylic acid by Fusarium graminearum. Fungal Biol 2018; 123:77-86. [PMID: 30654960 DOI: 10.1016/j.funbio.2018.11.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/23/2018] [Accepted: 11/08/2018] [Indexed: 12/20/2022]
Abstract
Fusarium head blight (FHB) is a major cereal crop disease, caused most frequently by the fungus Fusarium graminearum. We have previously demonstrated that F. graminearum can utilize SA as sole source of carbon to grow. In this current study, we further characterized selected four fungal SA-responsive genes that are predicted to encode salicylic acid (SA)-degrading enzymes and we used a gene replacement approach to characterize them further. These included two genes predicted to encode a salicylate 1-monooxygenase, FGSG_03657 and FGSG_09063, a catechol 1, 2-dioxygenase gene, FGSG_03667, and a 2, 3-dihydroxybenzoic acid decarboxylase gene, FGSG_09061. For each gene, three independent gene replacement strains were assayed for their ability to degrade salicylic acid in liquid culture. Salicylate 1-monooxygenase FGSG_03657 and catechol 1, 2-dioxygenase FGSG_03667 were shown to be essential for SA degradation, while a loss of 2, 3-dihydroxybenzoic acid decarboxylase FGSG_09061 caused only a partial reduction of SA degradation and a loss of salicylate 1-monooxygenase FGSG_09063 had no effect when compared to wild type culture. Salicylate 1-monooxygenase FGSG_03657 and catechol 1, 2-dioxygenase FGSG_03667 were identified as the first two key enzyme steps of SA degradation via catechol in the β-ketoadipate pathway. Expression profiles for all four genes were also determined in liquid culture and in planta. Salicylate 1-monooxygenase FGSG_03657 and catechol 1, 2-dioxygenase FGSG_03667 were co-expressed and their expression was substrate dependent in liquid culture; however their expression was uncoupled in planta. Disruption of the gene for catechol 1, 2-dioxygenase FGSG_03667 was shown to have no effect on fungal virulence on wheat. Our results with 2, 3-dihydroxybenzoic acid decarboxylase FGSG_09061 raise the possibility of an alternate non-oxidative decarboxylation pathway for the conversion of SA to catechol via 2, 3-dihydrozybenzoic acid and for a connection between the oxidative and the non-oxidative decarboxylation pathways for SA conversion.
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Affiliation(s)
- Hélène Rocheleau
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada.
| | - Reem Al-Harthi
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada; Department of Biology, University of Ottawa, 30 Marie Currie, Ottawa, ON K1N 6N5, Canada.
| | - Thérèse Ouellet
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, 960 Carling Ave, Ottawa, ON K1A 0C6, Canada.
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14
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Mangwanda R, Zwart L, van der Merwe NA, Moleleki LN, Berger DK, Myburg AA, Naidoo S. Localization and Transcriptional Responses of Chrysoporthe austroafricana in Eucalyptus grandis Identify Putative Pathogenicity Factors. Front Microbiol 2016; 7:1953. [PMID: 28008326 PMCID: PMC5143476 DOI: 10.3389/fmicb.2016.01953] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/21/2016] [Indexed: 12/18/2022] Open
Abstract
Chrysoporthe austroafricana is a fungal pathogen that causes the development of stem cankers on susceptible Eucalyptus grandis trees. Clones of E. grandis that are partially resistant and highly susceptible have been identified based on the extent of lesion formation on the stem upon inoculation with C. austroafricana. These interactions have been used as a model pathosystem to enhance our understanding of interactions between pathogenic fungi and woody hosts, which may be different to herbaceous hosts. In previous research, transcriptomics of host responses in these two clones to C. austroafricana suggested roles for salicylic acid and gibberellic acid phytohormone signaling in defense. However, it is unclear how the pathogen infiltrates host tissue and which pathogenicity factors facilitate its spread in the two host genotypes. The aim of this study was to investigate these two aspects of the E. grandis-C. austroafricana interaction and to test the hypothesis that the pathogen possesses mechanisms to modulate the tree phytohormone-mediated defenses. Light microscopy showed that the pathogen occurred in most cell types and structures within infected E. grandis stem tissue. Notably, the fungus appeared to spread through the stem by penetrating cell wall pits. In order to understand the molecular interaction between these organisms and predict putative pathogenicity mechanisms of C. austroafricana, fungal gene expression was studied in vitro and in planta. Fungal genes associated with cell wall degradation, carbohydrate metabolism and phytohormone manipulation were expressed in planta by C. austroafricana. These genes could be involved in fungal spread by facilitating cell wall pit degradation and manipulating phytohormone mediated defense in each host environment, respectively. Specifically, the in planta expression of an ent-kaurene oxidase and salicylate hydroxylase in C. austroafricana suggests putative mechanisms by which the pathogen can modulate the phytohormone-mediated defenses of the host. These mechanisms have been reported in herbaceous plant-pathogen interactions, supporting the notion that these aspects of the interaction are similar in a woody species. This study highlights ent-kaurene oxidase and salicylate hydroxylase as candidates for further functional characterization.
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Affiliation(s)
- Ronishree Mangwanda
- Department of Genetics, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
| | - Lizahn Zwart
- Department of Genetics, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
| | - Nicolaas A. van der Merwe
- Department of Genetics, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
| | - Lucy Novungayo Moleleki
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute, University of PretoriaPretoria, South Africa
| | - Dave Kenneth Berger
- Department of Plant and Soil Sciences, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
| | - Alexander A. Myburg
- Department of Genetics, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
| | - Sanushka Naidoo
- Department of Genetics, Forestry and Agricultural Biotechnology Institute, Genomics Research Institute, University of PretoriaPretoria, South Africa
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15
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Rabe F, Seitner D, Bauer L, Navarrete F, Czedik-Eysenberg A, Rabanal FA, Djamei A. Phytohormone sensing in the biotrophic fungus Ustilago maydis - the dual role of the transcription factor Rss1. Mol Microbiol 2016; 102:290-305. [PMID: 27387604 PMCID: PMC5082525 DOI: 10.1111/mmi.13460] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2016] [Indexed: 12/30/2022]
Abstract
The phenolic compound salicylic acid (SA) is a key signalling molecule regulating local and systemic plant defense responses, mainly against biotrophs. Many microbial organisms, including pathogens, share the ability to degrade SA. However, the mechanism by which they perceive SA is unknown. Here we show that Ustilago maydis, the causal agent of corn smut disease, employs a so far uncharacterized SA sensing mechanism. We identified and characterized the novel SA sensing regulator, Rss1, a binuclear zinc cluster protein with dual functions as putative SA receptor and transcriptional activator regulating genes important for SA and tryptophan degradation. Rss1 represents a major component in the identified SA sensing pathway during the fungus' saprophytic stage. However, Rss1 does not have a detectable impact on virulence. The data presented in this work indicate that alternative or redundant sensing cascades exist that regulate the expression of SA-responsive genes in U. maydis during its pathogenic development.
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Affiliation(s)
- Franziska Rabe
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Denise Seitner
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Lisa Bauer
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Fernando Navarrete
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Angelika Czedik-Eysenberg
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Fernando A Rabanal
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria
| | - Armin Djamei
- Vienna Biocenter (VBC), Gregor Mendel Institute (GMI), Austrian Academy of Sciences (OEAW), Dr. Bohr-Gasse 3, Vienna, 1030, Austria.
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16
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Dieryckx C, Gaudin V, Dupuy JW, Bonneu M, Girard V, Job D. Beyond plant defense: insights on the potential of salicylic and methylsalicylic acid to contain growth of the phytopathogen Botrytis cinerea. FRONTIERS IN PLANT SCIENCE 2015; 6:859. [PMID: 26528317 PMCID: PMC4607878 DOI: 10.3389/fpls.2015.00859] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/29/2015] [Indexed: 05/27/2023]
Abstract
Using Botrytis cinerea we confirmed in the present work several previous studies showing that salicylic acid, a main plant hormone, inhibits fungal growth in vitro. Such an inhibitory effect was also observed for the two salicylic acid derivatives, methylsalicylic and acetylsalicylic acid. In marked contrast, 5-sulfosalicylic acid was totally inactive. Comparative proteomics from treated vs. control mycelia showed that both the intracellular and extracellular proteomes were affected in the presence of salicylic acid or methylsalicylic acid. These data suggest several mechanisms that could potentially account for the observed fungal growth inhibition, notably pH regulation, metal homeostasis, mitochondrial respiration, ROS accumulation and cell wall remodeling. The present observations support a role played by the phytohormone SA and derivatives in directly containing the pathogen. Data are available via ProteomeXchange with identifier PXD002873.
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Affiliation(s)
- Cindy Dieryckx
- Laboratoire Mixte UMR 5240, Plateforme de Protéomique, Centre National de la Recherche ScientifiqueLyon, France
| | - Vanessa Gaudin
- Laboratoire Mixte UMR 5240, Plateforme de Protéomique, Centre National de la Recherche ScientifiqueLyon, France
| | - Jean-William Dupuy
- Plateforme Protéome, Centre de Génomique Fonctionnelle, Université de BordeauxBordeaux, France
| | - Marc Bonneu
- Plateforme Protéome, Centre de Génomique Fonctionnelle, Université de BordeauxBordeaux, France
| | - Vincent Girard
- Laboratoire Mixte UMR 5240, Plateforme de Protéomique, Centre National de la Recherche ScientifiqueLyon, France
| | - Dominique Job
- Laboratoire Mixte UMR 5240, Plateforme de Protéomique, Centre National de la Recherche ScientifiqueLyon, France
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17
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Marchlewicz A, Guzik U, Wojcieszyńska D. Over-the-Counter Monocyclic Non-Steroidal Anti-Inflammatory Drugs in Environment-Sources, Risks, Biodegradation. WATER, AIR, AND SOIL POLLUTION 2015; 226:355. [PMID: 26478634 PMCID: PMC4600096 DOI: 10.1007/s11270-015-2622-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 09/22/2015] [Indexed: 05/31/2023]
Abstract
Recently, the increased use of monocyclic non-steroidal anti-inflammatory drugs has resulted in their presence in the environment. This may have potential negative effects on living organisms. The biotransformation mechanisms of monocyclic non-steroidal anti-inflammatory drugs in the human body and in other mammals occur by hydroxylation and conjugation with glycine or glucuronic acid. Biotransformation/biodegradation of monocyclic non-steroidal anti-inflammatory drugs in the environment may be caused by fungal or bacterial microorganisms. Salicylic acid derivatives are degraded by catechol or gentisate as intermediates which are cleaved by dioxygenases. The key intermediate of the paracetamol degradation pathways is hydroquinone. Sometimes, after hydrolysis of this drug, 4-aminophenol is formed, which is a dead-end metabolite. Ibuprofen is metabolized by hydroxylation or activation with CoA, resulting in the formation of isobutylocatechol. The aim of this work is to attempt to summarize the knowledge about environmental risk connected with the presence of over-the-counter anti-inflammatory drugs, their sources and the biotransformation and/or biodegradation pathways of these drugs.
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Affiliation(s)
- Ariel Marchlewicz
- Department of Biochemistry, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland
| | - Urszula Guzik
- Department of Biochemistry, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland
| | - Danuta Wojcieszyńska
- Department of Biochemistry, Faculty of Biology and Environmental Protection, University of Silesia in Katowice, Jagiellonska 28, 40-032 Katowice, Poland
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18
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Tanaka S, Han X, Kahmann R. Microbial effectors target multiple steps in the salicylic acid production and signaling pathway. FRONTIERS IN PLANT SCIENCE 2015; 6:349. [PMID: 26042138 PMCID: PMC4436567 DOI: 10.3389/fpls.2015.00349] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 05/03/2015] [Indexed: 05/19/2023]
Abstract
Microbes attempting to colonize plants are recognized through the plant immune surveillance system. This leads to a complex array of global as well as specific defense responses, which are often associated with plant cell death and subsequent arrest of the invader. The responses also entail complex changes in phytohormone signaling pathways. Among these, salicylic acid (SA) signaling is an important pathway because of its ability to trigger plant cell death. As biotrophic and hemibiotrophic pathogens need to invade living plant tissue to cause disease, they have evolved efficient strategies to downregulate SA signaling by virulence effectors, which can be proteins or secondary metabolites. Here we review the strategies prokaryotic pathogens have developed to target SA biosynthesis and signaling, and contrast this with recent insights into how plant pathogenic eukaryotic fungi and oomycetes accomplish the same goal.
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Affiliation(s)
| | | | - Regine Kahmann
- *Correspondence: Regine Kahmann, Department of Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 10, D-35043 Marburg, Germany,
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