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Secondary Metabolites from the Endoparasitic Nematophagous Fungus Harposporium anguillulae YMF 1.01751. Microorganisms 2022; 10:microorganisms10081553. [PMID: 36013971 PMCID: PMC9415808 DOI: 10.3390/microorganisms10081553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
Harposporium anguillulae, an endoparasitic nematophagous fungus (ENF), is a model fungus from which the genus Harposporium was established. It can infect nematodes via ingested conidia. In this paper, the morphology and nematode–fungus interaction between Panagrellus redivivus and H. anguillulae were observed by scanning electron microscopy (SEM). The secondary metabolites of H. anguillulae were also studied. Seven metabolites were purified and identified from an ethyl acetate extract of broth and a methanol extract of mycelium. These include a new polyketone 5-hydroxy-3-(hydroxymethyl)-6-methyl-2H-pyran-2-one (1) and six known metabolites (17R)-17-methylincisterol (2), eburicol (3), ergosterol peroxide (4), terpendole C (5), (3β,5α,9β,22E)-3,5-dihydroxy-ergosta-7,22-dien-6-one (6), and 5α,6β-epoxy-(22E,24R)-ergosta-8,22-diene- 3β,7α-diol (7). These metabolites were assayed for their activity against plant root-knot nematode, Meloidogyne incognita, and the results showed that terpendole C (5) had weak nematicidal activity but also that other compounds did not have evident activity at a concentration of 400 μg mL−1. Compound 1 exhibited an attractive effect towards P. redivivus.
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Lin D, Yang G, Dou P, Qian S, Zhao L, Yang Y, Fanin N. Microplastics negatively affect soil fauna but stimulate microbial activity: insights from a field-based microplastic addition experiment. Proc Biol Sci 2020; 287:20201268. [PMID: 32873207 DOI: 10.1098/rspb.2020.1268] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microplastics are recognized as an emerging contaminant worldwide. Although microplastics have been shown to strongly affect organisms in aquatic environments, less is known about whether and how microplastics can affect different taxa within a soil community, and it is unclear whether these effects can cascade through soil food webs. By conducting a microplastic manipulation experiment, i.e. adding low-density polyethylene fragments in the field, we found that microplastic addition significantly affected the composition and abundance of microarthropod and nematode communities. Contrary to soil fauna, we found only small effects of microplastics on the biomass and structure of soil microbial communities. Nevertheless, structural equation modelling revealed that the effects of microplastics strongly cascade through the soil food webs, leading to the modification of microbial functioning with further potential consequences on soil carbon and nutrient cycling. Our results highlight that taking into account the effects of microplastics at different trophic levels is important to elucidate the mechanisms underlying the ecological impacts of microplastic pollution on soil functioning.
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Affiliation(s)
- Dunmei Lin
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Guangrong Yang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Pengpeng Dou
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Shenhua Qian
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Liang Zhao
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Yongchuan Yang
- Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, People's Republic of China
| | - Nicolas Fanin
- INRAE, Bordeaux Sciences Agro, UMR 1391 Interaction Soil Plant Atmosphere (ISPA), 71 Avenue Edouard Bourlaux, 33882 Villenave-d'Ornon cedex, France
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Birkemoe T, Jacobsen RM, Sverdrup-Thygeson A, Biedermann PHW. Insect-Fungus Interactions in Dead Wood Systems. SAPROXYLIC INSECTS 2018. [DOI: 10.1007/978-3-319-75937-1_12] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Gkarmiri K, Finlay RD, Alström S, Thomas E, Cubeta MA, Högberg N. Transcriptomic changes in the plant pathogenic fungus Rhizoctonia solani AG-3 in response to the antagonistic bacteria Serratia proteamaculans and Serratia plymuthica. BMC Genomics 2015; 16:630. [PMID: 26296338 PMCID: PMC4546130 DOI: 10.1186/s12864-015-1758-z] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 07/07/2015] [Indexed: 11/23/2022] Open
Abstract
Background Improved understanding of bacterial-fungal interactions in the rhizosphere should assist in the successful application of bacteria as biological control agents against fungal pathogens of plants, providing alternatives to chemicals in sustainable agriculture. Rhizoctonia solani is an important soil-associated fungal pathogen and its chemical treatment is not feasible or economic. The genomes of the plant-associated bacteria Serratia proteamaculans S4 and Serratia plymuthica AS13 have been sequenced, revealing genetic traits that may explain their diverse plant growth promoting activities and antagonistic interactions with R. solani. To understand the functional response of this pathogen to different bacteria and to elucidate whether the molecular mechanisms that the fungus exploits involve general stress or more specific responses, we performed a global transcriptome profiling of R. solani Rhs1AP anastomosis group 3 (AG-3) during interaction with the S4 and AS13 species of Serratia using RNA-seq. Results Approximately 104,504 million clean 75-100 bp paired-end reads were obtained from three libraries, each in triplicate (AG3-Control, AG3-S4 and AG3-AS13). Transcriptome analysis revealed that approximately 10 % of the fungal transcriptome was differentially expressed during challenge with Serratia. The numbers of S4- and AS13-specific differentially expressed genes (DEG) were 866 and 292 respectively, while there were 1035 common DEGs in the two treatment groups. Four hundred and sixty and 242 genes respectively had values of log2 fold-change > 3 and for further analyses this cut-off value was used. Functional classification of DEGs based on Gene Ontology enrichment analysis and on KEGG pathway annotations revealed a general shift in fungal gene expression in which genes related to xenobiotic degradation, toxin and antioxidant production, energy, carbohydrate and lipid metabolism and hyphal rearrangements were subjected to transcriptional regulation. Conclusions This RNA-seq profiling generated a novel dataset describing the functional response of the phytopathogen R. solani AG3 to the plant-associated Serratia bacteria S4 and AS13. Most genes were regulated in the same way in the presence of both bacterial isolates, but there were also some strain-specific responses. The findings in this study will be beneficial for further research on biological control and in depth exploration of bacterial-fungal interactions in the rhizosphere. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1758-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Konstantia Gkarmiri
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007, Uppsala, Sweden.
| | - Roger D Finlay
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007, Uppsala, Sweden.
| | - Sadhna Alström
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007, Uppsala, Sweden.
| | - Elizabeth Thomas
- Department of Plant Pathology, Center for Integrated Fungal Research, Fungal Disease Ecology, Genetics and Population Biology, North Carolina State University, 851 Main Campus Drive, Suite 233, 225 Partners III, Raleigh, NC, 27606, USA.
| | - Marc A Cubeta
- Department of Plant Pathology, Center for Integrated Fungal Research, Fungal Disease Ecology, Genetics and Population Biology, North Carolina State University, 851 Main Campus Drive, Suite 233, 225 Partners III, Raleigh, NC, 27606, USA.
| | - Nils Högberg
- Department of Forest Mycology and Plant Pathology, Uppsala BioCenter, Swedish University of Agricultural Sciences, Box 7026, SE-75007, Uppsala, Sweden.
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A'Bear AD, Jones TH, Boddy L. Potential impacts of climate change on interactions among saprotrophic cord-forming fungal mycelia and grazing soil invertebrates. FUNGAL ECOL 2014. [DOI: 10.1016/j.funeco.2013.01.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Crowther TW, Boddy L, Hefin Jones T. Functional and ecological consequences of saprotrophic fungus-grazer interactions. ISME JOURNAL 2012; 6:1992-2001. [PMID: 22717883 DOI: 10.1038/ismej.2012.53] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Saprotrophic fungi are key regulators of nutrient cycling in terrestrial ecosystems. They are the primary agents of plant litter decomposition and their hyphal networks, which grow throughout the soil-litter interface, represent highly dynamic channels through which nutrients are readily distributed. By ingesting hyphae and dispersing spores, soil invertebrates, including Arthropoda, Oligochaetae and Nematoda, influence fungal-mediated nutrient distribution within soil. Fungal physiological responses to grazing include changes to hydrolytic enzyme production and respiration rates. These directly affect nutrient mineralisation and the flux of CO(2) between terrestrial and atmospheric pools. Preferential grazing may also exert selective pressures on saprotrophic communities, driving shifts in fungal succession and community composition. These functional and ecological consequences of grazing are intrinsically linked, and influenced by invertebrate grazing intensity. High-intensity grazing often reduces fungal growth and activity, whereas low-intensity grazing can have stimulatory effects. Grazing intensity is directly related to invertebrate abundance, and varies dramatically between species and functional groups. Invertebrate diversity and community composition, therefore, represent key factors determining the functioning of saprotrophic fungal communities and the services they provide.
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Affiliation(s)
- Thomas W Crowther
- Organisms and Environment Division, Cardiff School of Biosciences, Cardiff University, Cardiff, UK.
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Crowther TW, Boddy L, Jones TH. Outcomes of fungal interactions are determined by soil invertebrate grazers. Ecol Lett 2011; 14:1134-42. [PMID: 21929699 DOI: 10.1111/j.1461-0248.2011.01682.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Saprotrophic fungal community composition, determined by the outcome of competitive mycelial interactions, is one of the many key factors affecting soil nutrient mineralisation and decomposition rates. Fungal communities are not generally predicted to be regulated by top-down factors, such as predation, but rather by bottom-up factors, including resource availability. We show that invertebrate grazers can exert selective pressures on fungal decomposer communities in soil, reversing the outcomes of competitive interactions. By feeding selectively on the cord-forming fungus Resinicium bicolor, isopods prevented the competitive exclusion of Hypholoma fasciculare and Phanerochaete velutina in soil and wood. Nematode populations also reversed the outcomes of competitive interactions by stimulating growth of less competitive fungi. These represent two opposing mechanisms by which soil fauna may influence fungal community composition and diversity. Factors affecting soil invertebrate communities will have direct consequences for fungal-mediated nutrient cycling in woodland soils.
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Affiliation(s)
- Thomas W Crowther
- Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
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Crowther TW, Boddy L, Jones TH. Species-specific effects of soil fauna on fungal foraging and decomposition. Oecologia 2011; 167:535-45. [DOI: 10.1007/s00442-011-2005-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 04/18/2011] [Indexed: 11/30/2022]
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Chapter 9 Interactions between basidiomycota and invertebrates. BRITISH MYCOLOGICAL SOCIETY SYMPOSIA SERIES 2008. [DOI: 10.1016/s0275-0287(08)80011-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Chapter 2 Enzymes of saprotrophic basidiomycetes. BRITISH MYCOLOGICAL SOCIETY SYMPOSIA SERIES 2008. [DOI: 10.1016/s0275-0287(08)80004-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Bretherton S, Tordoff GM, Jones TH, Boddy L. Compensatory growth of Phanerochaete velutina mycelial systems grazed by Folsomia candida (Collembola). FEMS Microbiol Ecol 2006; 58:33-40. [PMID: 16958906 DOI: 10.1111/j.1574-6941.2006.00149.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Phanerochaete velutina is a major agent of wood decomposition in temperate forests. It grows out of woody resources in search of other resources and is then vulnerable to grazing by invertebrates. The aim of this study was to determine how continuous grazing and grazing for only 2 days by different densities of collembola, Folsomia candida, affect mycelial development (radial extension, hyphal coverage and fractal dimension) of P. velutina growing across non-sterile soil. High density (80 collembola) continuous grazing resulted in different mycelial foraging patterns compared to controls and lower density (20 and 40 collembola) continuous grazing: radial extension rate was reduced from 8.4 mm day(-1) (control) to 6.9 mm day(-1) (80 collembola), hyphal coverage was reduced to 81% of controls and mass fractal dimension increased from 1.68 (control) to 1.72 (80 collembola). There was evidence of over-compensatory growth: when high density grazing ceased the new growth was considerably greater (38%) than in controls. Grazing also resulted in growth stimulation: at low density continuous grazing (20 collembola) hyphal coverage was 15.6% greater than in controls. The ecological implications of compensatory and stimulatory growth in fungal-invertebrate interactions are considered.
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Affiliation(s)
- Sam Bretherton
- Cardiff School of Biosciences, Cardiff CF10 3TL, Wales, UK
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Wood J, Tordoff GM, Jones TH, Boddy L. Reorganization of mycelial networks of Phanerochaete velutina in response to new woody resources and collembola (Folsomia candida) grazing. ACTA ACUST UNITED AC 2006; 110:985-93. [PMID: 16891104 DOI: 10.1016/j.mycres.2006.05.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2005] [Revised: 03/31/2006] [Accepted: 05/07/2006] [Indexed: 11/17/2022]
Abstract
Mycelial development of Phanerochaete velutina extending from wood inocula in 57 x 57 cm trays of non-sterile soil was characterized after adding: (1) collembola; (2) new wood resources; (3) both new wood resources and collembola; and (4) no new resources and no collembola. After 99 d, all systems had produced distinct mycelial cords, much of the diffuse mycelium and thinner cords that were produced early on having regressed. Systems to which new resources (but no collembola) had been added developed thick cords interconnecting inocula with new resources, and much of the non-connected mycelium regressed. Nonetheless, these systems had significantly greater hyphal coverage and mass fractal dimension than the other treatments, resulting from outgrowth from the new resources. Unexpectedly, morphology of grazed systems with no added resources was very similar to that of ungrazed systems with no added resources, apparently because the collembola grazed on senescing hyphae that would ultimately have regressed. Where new resources and collembola were added, there was proliferation of fine mycelium along connective cords and elsewhere, but this was not as extensive as in the new resource/no collembola systems, the fine mycelium apparently being grazed in patches. Fungus gnat (family Sciaridae) larvae contaminated eight (out of 14) trays with no added collembola, but none of the systems to which collembola had been added. They burrowed around the wood and caused cords to be severed.
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Affiliation(s)
- Jonathan Wood
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3TL, Wales, UK
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Harold S, Tordoff GM, Jones TH, Boddy L. Mycelial responses of Hypholoma fasciculare to collembola grazing: effect of inoculum age, nutrient status and resource quality. ACTA ACUST UNITED AC 2005; 109:927-35. [PMID: 16175795 DOI: 10.1017/s095375620500331x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The effects of grazing by the collembolan Folsomia candida on mycelial foraging patterns of Hypholoma fasciculare growing from beech (Fagus sylvatica) wood block inocula in trays of non-sterile soil was investigated. The wood inocula differed in size, state of decay (time for which wood has been colonized: 2 yr, 1 yr, 6 and 3 months) and nutrient status (inocula colonized on malt agar or nutrient agar). Mycelia were most luxuriant, had greater hyphal coverage and extended more rapidly from 2 yr old than younger inocula, from 4 cm3 than 1 cm3 inocula, and from inocula colonized on malt extract agar rather than on distilled water agar. Grazing dramatically reduced coverage and extension, especially in the less luxuriant systems characterized by many fine hyphae and fewer mycelial cords. Grazing by collembola often resulted in points of more rapid outgrowth as cords with a fanned margin. Results are discussed in terms of fungal foraging strategies.
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Affiliation(s)
- Simon Harold
- Cardiff School of Biosciences, Cardiff CF10 3TL, UK
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Crowe JD, Olsson S. Induction of laccase activity in Rhizoctonia solani by antagonistic Pseudomonas fluorescens strains and a range of chemical treatments. Appl Environ Microbiol 2001; 67:2088-94. [PMID: 11319086 PMCID: PMC92841 DOI: 10.1128/aem.67.5.2088-2094.2001] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fungi often produce the phenoloxidase enzyme laccase during interactions with other organisms, an observation relevant to the development of biocontrols. By incorporating the laccase substrate 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) into agar, we analyzed laccase induction in the plant-pathogenic fungus Rhizoctonia solani when paired against isolates of the soil bacterium Pseudomonas fluorescens. Substantial induction of R. solani laccase was seen only in pairings with strains of P. fluorescens known to produce antifungal metabolites. To study laccase induction further, a range of chemical treatments was applied to R. solani liquid cultures. p-Anisidine, copper(II), manganese(II), calcium ionophore A23187, lithium chloride, calcium chloride, cyclic AMP (cAMP), caffeine, amphotericin B, paraquat, ethanol, and isopropanol were all found to induce laccase; however, the P. fluorescens metabolite viscosinamide did not do so at the concentrations tested. The stress caused by these treatments was assessed by measuring changes in lipid peroxidation levels and dry weight. The results indicated that the laccase induction seen in pairing plate experiments was most likely due to calcium or heat shock signaling in response to the effects of bacterial metabolites, but that heavy metal and cAMP-driven laccase induction was involved in sclerotization.
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Affiliation(s)
- J D Crowe
- Section of Genetics and Microbiology, Department of Ecology, The Royal Veterinary and Agricultural University, 40, Thorvaldsenvej, DK-1871 Frederiksberg, Copenhagen, Denmark
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Boddy L. Saprotrophic cord-forming fungi: warfare strategies and other ecological aspects. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/s0953-7562(09)80141-x] [Citation(s) in RCA: 147] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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