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Hale B, Watts C, Conatser M, Brown E, Wijeratne AJ. Fine-scale characterization of the soybean rhizosphere microbiome via synthetic long reads and avidity sequencing. ENVIRONMENTAL MICROBIOME 2024; 19:46. [PMID: 38997772 PMCID: PMC11241880 DOI: 10.1186/s40793-024-00590-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 07/03/2024] [Indexed: 07/14/2024]
Abstract
BACKGROUND The rhizosphere microbiome displays structural and functional dynamism driven by plant, microbial, and environmental factors. While such plasticity is a well-evidenced determinant of host health, individual and community-level microbial activity within the rhizosphere remain poorly understood, due in part to the insufficient taxonomic resolution achieved through traditional marker gene amplicon sequencing. This limitation necessitates more advanced approaches (e.g., long-read sequencing) to derive ecological inferences with practical application. To this end, the present study coupled synthetic long-read technology with avidity sequencing to investigate eukaryotic and prokaryotic microbiome dynamics within the soybean (Glycine max) rhizosphere under field conditions. RESULTS Synthetic long-read sequencing permitted de novo reconstruction of the entire 18S-ITS1-ITS2 region of the eukaryotic rRNA operon as well as all nine hypervariable regions of the 16S rRNA gene. All full-length, mapped eukaryotic amplicon sequence variants displayed genus-level classification, and 44.77% achieved species-level classification. The resultant eukaryotic microbiome encompassed five kingdoms (19 genera) of protists in addition to fungi - a depth unattainable with conventional short-read methods. In the prokaryotic fraction, every full-length, mapped amplicon sequence variant was resolved at the species level, and 23.13% at the strain level. Thirteen species of Bradyrhizobium were thereby distinguished in the prokaryotic microbiome, with strain-level identification of the two Bradyrhizobium species most reported to nodulate soybean. Moreover, the applied methodology delineated structural and compositional dynamism in response to experimental parameters (i.e., growth stage, cultivar, and biostimulant application), unveiled a saprotroph-rich core microbiome, provided empirical evidence for host selection of mutualistic taxa, and identified key microbial co-occurrence network members likely associated with edaphic and agronomic properties. CONCLUSIONS This study is the first to combine synthetic long-read technology and avidity sequencing to profile both eukaryotic and prokaryotic fractions of a plant-associated microbiome. Findings herein provide an unparalleled taxonomic resolution of the soybean rhizosphere microbiota and represent significant biological and technological advancements in crop microbiome research.
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Affiliation(s)
- Brett Hale
- AgriGro Incorporated, Doniphan, MO, USA
- Arkansas Biosciences Institute, Arkansas State University, State University, AR, USA
- College of Science and Mathematics, Arkansas State University, State University, AR, USA
| | - Caitlin Watts
- College of Agriculture, Arkansas State University, State University, AR, USA
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
| | - Matthew Conatser
- College of Agriculture, Arkansas State University, State University, AR, USA
| | - Edward Brown
- College of Agriculture, Arkansas State University, State University, AR, USA
| | - Asela J Wijeratne
- Arkansas Biosciences Institute, Arkansas State University, State University, AR, USA.
- College of Science and Mathematics, Arkansas State University, State University, AR, USA.
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Sorwar E, Oliveira JIN, Malar C M, Krüger M, Corradi N. Assembly and comparative analyses of the Geosiphon pyriformis metagenome. Environ Microbiol 2024; 26:e16681. [PMID: 39054868 DOI: 10.1111/1462-2920.16681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 07/09/2024] [Indexed: 07/27/2024]
Abstract
Geosiphon pyriformis, a representative of the fungal sub-phylum Glomeromycotina, is unique in its endosymbiosis with cyanobacteria within a fungal cell. This symbiotic relationship occurs in bladders containing nuclei of G. pyriformis, Mollicutes-like bacterial endosymbionts (MRE), and photosynthetically active and dividing cells of Nostoc punctiforme. Recent genome analyses have shed light on the biology of G. pyriformis, but the genome content and biology of its endosymbionts remain unexplored. To fill this gap, we gathered and examined metagenomic data from the bladders of G. pyriformis, where N. punctiforme and MRE are located. This ensures that our analyses are focused on the organs directly involved in the symbiosis. By comparing this data with the genetic information of related cyanobacteria and MREs from other species of Arbuscular Mycorrhizal Fungi, we aimed to reveal the genetic content of these organisms and understand how they interact at a genetic level to establish a symbiotic relationship. Our analyses uncovered significant gene expansions in the Nostoc endosymbiont, particularly in mobile elements and genes potentially involved in xenobiotic degradation. We also confirmed that the MRE of Glomeromycotina are monophyletic and possess a highly streamlined genome. These genomes show dramatic differences in both structure and content, including the presence of enzymes involved in environmental sensing and stress response.
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Affiliation(s)
- Essam Sorwar
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Mathu Malar C
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Manuela Krüger
- Institute of Experimental Botany, The Czech Academy of Science, Prague, Czech Republic
| | - Nicolas Corradi
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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Zhang F, Li Y, Ji B, Dong S. Spatial distribution and drivers of arbuscular mycorrhizal fungi on the Tibetan Plateau. FRONTIERS IN PLANT SCIENCE 2024; 15:1427850. [PMID: 39045593 PMCID: PMC11264307 DOI: 10.3389/fpls.2024.1427850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2024] [Accepted: 05/28/2024] [Indexed: 07/25/2024]
Abstract
Introduction Arbuscular mycorrhizal fungi (AMF) are pivotal in plant resource acquisition, mediating plant interactions, and influencing soil carbon dynamics. However, their biogeographical distribution in Tibetan alpine grasslands remains understudied. Methods In this research, we examined the distribution pattern of AMF communities and their key determinants along a 2000-km transect across the Tibetan plateau, encompassing 7 alpine meadows and 8 alpine steppes. Results Our findings indicate that AMF community diversity and composition exhibit similarities between alpine meadows and alpine steppes, primarily influenced by latitude and evapotranspiration. At the genus level, Glomus predominated in both alpine meadow (36.49%±2.67%) and alpine steppe (41.87%±2.36%) soils, followed by Paraglomus (27.14%±3.69%, 32.34%±3.28%). Furthermore, a significant decay relationship of AMF community was observed over geographical distance. Null model analyses revealed that random processes predominantly (>50%) drove the assembly of AMF communities. Discussion In summary, our study elucidates the spatial distribution pattern of AMF in Tibetan plateau grasslands and underscores the significant influence of geographical and climatic factors on AMF community dynamics.
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Affiliation(s)
| | - Yaoming Li
- School of Grassland Science, Beijing Forestry University, Beijing, China
| | | | - Shikui Dong
- School of Grassland Science, Beijing Forestry University, Beijing, China
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Oliveira JIN, Corradi N. Strain-specific evolution and host-specific regulation of transposable elements in the model plant symbiont Rhizophagus irregularis. G3 (BETHESDA, MD.) 2024; 14:jkae055. [PMID: 38507600 PMCID: PMC11075540 DOI: 10.1093/g3journal/jkae055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 12/06/2023] [Accepted: 03/07/2024] [Indexed: 03/22/2024]
Abstract
Transposable elements (TEs) are repetitive DNA that can create genome structure and regulation variability. The genome of Rhizophagus irregularis, a widely studied arbuscular mycorrhizal fungus (AMF), comprises ∼50% repetitive sequences that include TEs. Despite their abundance, two-thirds of TEs remain unclassified, and their regulation among AMF life stages remains unknown. Here, we aimed to improve our understanding of TE diversity and regulation in this model species by curating repeat datasets obtained from chromosome-level assemblies and by investigating their expression across multiple conditions. Our analyses uncovered new TE superfamilies and families in this model symbiont and revealed significant differences in how these sequences evolve both within and between R. irregularis strains. With this curated TE annotation, we also found that the number of upregulated TE families in colonized roots is 4 times higher than in the extraradical mycelium, and their overall expression differs depending on the plant host. This work provides a fine-scale view of TE diversity and evolution in model plant symbionts and highlights their transcriptional dynamism and specificity during host-microbe interactions. We also provide Hidden Markov Model profiles of TE domains for future manual curation of uncharacterized sequences (https://github.com/jordana-olive/TE-manual-curation/tree/main).
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Affiliation(s)
| | - Nicolas Corradi
- Department of Biology, Faculty of Sciences, University of Ottawa, Ottawa, ON, Canada K1N 6N5
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Martin FM, van der Heijden MGA. The mycorrhizal symbiosis: research frontiers in genomics, ecology, and agricultural application. THE NEW PHYTOLOGIST 2024; 242:1486-1506. [PMID: 38297461 DOI: 10.1111/nph.19541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 12/07/2023] [Indexed: 02/02/2024]
Abstract
Mycorrhizal symbioses between plants and fungi are vital for the soil structure, nutrient cycling, plant diversity, and ecosystem sustainability. More than 250 000 plant species are associated with mycorrhizal fungi. Recent advances in genomics and related approaches have revolutionized our understanding of the biology and ecology of mycorrhizal associations. The genomes of 250+ mycorrhizal fungi have been released and hundreds of genes that play pivotal roles in regulating symbiosis development and metabolism have been characterized. rDNA metabarcoding and metatranscriptomics provide novel insights into the ecological cues driving mycorrhizal communities and functions expressed by these associations, linking genes to ecological traits such as nutrient acquisition and soil organic matter decomposition. Here, we review genomic studies that have revealed genes involved in nutrient uptake and symbiosis development, and discuss adaptations that are fundamental to the evolution of mycorrhizal lifestyles. We also evaluated the ecosystem services provided by mycorrhizal networks and discuss how mycorrhizal symbioses hold promise for sustainable agriculture and forestry by enhancing nutrient acquisition and stress tolerance. Overall, unraveling the intricate dynamics of mycorrhizal symbioses is paramount for promoting ecological sustainability and addressing current pressing environmental concerns. This review ends with major frontiers for further research.
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Affiliation(s)
- Francis M Martin
- Université de Lorraine, INRAE, UMR IAM, Champenoux, 54280, France
- Institute of Applied Mycology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Marcel G A van der Heijden
- Department of Agroecology & Environment, Plant-Soil Interactions, Agroscope, Zürich, 8046, Switzerland
- Department of Plant and Microbial Biology, University of Zürich, Zürich, 8057, Switzerland
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Sena L, Mica E, Valè G, Vaccino P, Pecchioni N. Exploring the potential of endophyte-plant interactions for improving crop sustainable yields in a changing climate. FRONTIERS IN PLANT SCIENCE 2024; 15:1349401. [PMID: 38571718 PMCID: PMC10988515 DOI: 10.3389/fpls.2024.1349401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/05/2024] [Indexed: 04/05/2024]
Abstract
Climate change poses a major threat to global food security, significantly reducing crop yields as cause of abiotic stresses, and for boosting the spread of new and old pathogens and pests. Sustainable crop management as a route to mitigation poses the challenge of recruiting an array of solutions and tools for the new aims. Among these, the deployment of positive interactions between the micro-biotic components of agroecosystems and plants can play a highly significant role, as part of the agro-ecological revolution. Endophytic microorganisms have emerged as a promising solution to tackle this challenge. Among these, Arbuscular Mycorrhizal Fungi (AMF) and endophytic bacteria and fungi have demonstrated their potential to alleviate abiotic stresses such as drought and heat stress, as well as the impacts of biotic stresses. They can enhance crop yields in a sustainable way also by other mechanisms, such as improving the nutrient uptake, or by direct effects on plant physiology. In this review we summarize and update on the main types of endophytes, we highlight several studies that demonstrate their efficacy in improving sustainable yields and explore possible avenues for implementing crop-microbiota interactions. The mechanisms underlying these interactions are highly complex and require a comprehensive understanding. For this reason, omic technologies such as genomics, transcriptomics, proteomics, and metabolomics have been employed to unravel, by a higher level of information, the complex network of interactions between plants and microorganisms. Therefore, we also discuss the various omic approaches and techniques that have been used so far to study plant-endophyte interactions.
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Affiliation(s)
- Lorenzo Sena
- Dipartimento di Scienze della Vita, Sede Agraria, UNIMORE - Università di Modena e Reggio Emilia, Reggio Emilia, Italy
- Centro di Ricerca Cerealicoltura e Colture Industriali, CREA – Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria, Vercelli, Italy
| | - Erica Mica
- Dipartimento per lo Sviluppo Sostenibile e la Transizione Ecologica, UPO – Università del Piemonte Orientale, Complesso San Giuseppe, Vercelli, Italy
| | - Giampiero Valè
- Dipartimento per lo Sviluppo Sostenibile e la Transizione Ecologica, UPO – Università del Piemonte Orientale, Complesso San Giuseppe, Vercelli, Italy
| | - Patrizia Vaccino
- Centro di Ricerca Cerealicoltura e Colture Industriali, CREA – Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria, Vercelli, Italy
| | - Nicola Pecchioni
- Dipartimento di Scienze della Vita, Sede Agraria, UNIMORE - Università di Modena e Reggio Emilia, Reggio Emilia, Italy
- Centro di Ricerca Cerealicoltura e Colture Industriali, CREA – Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria, Vercelli, Italy
- Centro di Ricerca Cerealicoltura e Colture Industriali, CREA – Consiglio per la Ricerca in Agricoltura e l’Analisi dell’Economia Agraria, Foggia, Italy
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Secrets of the fungus-specific potassium channel TOK family. Trends Microbiol 2022; 31:511-520. [PMID: 36567187 DOI: 10.1016/j.tim.2022.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 12/25/2022]
Abstract
Several families of potassium (K+) channels are found in membranes of all eukaryotes, underlining the importance of K+ uptake and redistribution within and between cells and organs. Among them, TOK (tandem-pore outward-rectifying K+) channels consist of eight transmembrane domains and two pore domains per subunit organized in dimers. These channels were originally studied in yeast, but recent identifications and characterizations in filamentous fungi shed new light on this fungus-specific K+ channel family. Although their actual function in vivo is often puzzling, recent works indicate a role in cellular K+ homeostasis and even suggest a role in plant-fungus symbioses. This review aims at synthesizing the current knowledge on fungal TOK channels and discussing their potential role in yeasts and filamentous fungi.
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Phenol and Polyaromatic Hydrocarbons Are Stronger Drivers Than Host Plant Species in Shaping the Arbuscular Mycorrhizal Fungal Component of the Mycorrhizosphere. Int J Mol Sci 2022; 23:ijms232012585. [PMID: 36293448 PMCID: PMC9604154 DOI: 10.3390/ijms232012585] [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: 09/01/2022] [Revised: 10/10/2022] [Accepted: 10/17/2022] [Indexed: 11/30/2022] Open
Abstract
Changes in soil microbial communities in response to hydrocarbon pollution are critical indicators of disturbed ecosystem conditions. A core component of these communities that is functionally adjusted to the life-history traits of the host and environmental factors consists of arbuscular mycorrhizal fungi (AMF). AMF communities associated with Poa trivialis and Phragmites australis growing at a phenol and polynuclear aromatic hydrocarbon (PAH)-contaminated site and at an uncontaminated site were compared based on LSU rDNA sequencing. Dissimilarities in species composition and community structures indicated soil pollution as the main factor negatively affecting the AMF diversity. The AMF communities at the contaminated site were dominated by fungal generalists (Rhizophagus, Funneliformis, Claroideoglomus, Paraglomus) with wide ecological tolerance. At the control site, the AMF communities were characterized by higher taxonomic and functional diversity than those exposed to the contamination. The host plant identity was the main driver distinguishing the two AMF metacommunities. The AMF communities at the uncontaminated site were represented by Polonospora, Paraglomus, Oehlia, Nanoglomus, Rhizoglomus, Dominikia, and Microdominikia. Polonosporaceae and Paraglomeraceae were particularly dominant in the Ph. australis mycorrhizosphere. The high abundance of early diverging AMF could be due to the use of primers able to detect lineages such as Paraglomeracae that have not been recognized by previously used 18S rDNA primers.
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Sun J, Luo H, Yu Q, Kou B, Jiang Y, Weng L, Xiao C. Optimal NPK Fertilizer Combination Increases Panax ginseng Yield and Quality and Affects Diversity and Structure of Rhizosphere Fungal Communities. Front Microbiol 2022; 13:919434. [PMID: 35801112 PMCID: PMC9255912 DOI: 10.3389/fmicb.2022.919434] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 05/25/2022] [Indexed: 11/25/2022] Open
Abstract
Soil microorganisms affect crop rhizospheres via the transformation and transport of nutrients, which has important influences on soil fertility, carbon sequestration, and plant yield and health in agroecosystems. There are few reports on the effects of fertilizer application on the growth of Panax ginseng (C. A. Mey.) or the structure of its rhizosphere microbial communities. In this study, an orthogonal experimental design was used to explore the effects of nine different combinations of nitrogen (N), phosphorus (P), and potassium (K) fertilizers with different amounts and proportions on ginseng growth and accumulation of ginsenosides and the structure of rhizosphere soil fungal communities. Soil without fertilization was the control. With the combined application of NPK, ginseng growth and development increased. The fertilization scheme N3P1K3, with N fertilizer at 50 g·m−2, P fertilizer at 15 g·m−2, and K fertilizer at 60 g·m−2, had the most comprehensive benefit and significantly increased ginseng rhizome biomass and ginsenoside contents (Rg1, Re, Rf, Rg2, Rb1, Ro, Rc, Rb2, Rb3, and Rd). Amplicon sequencing showed that NPK application increased the diversity of fungal communities in ginseng rhizospheres, whereas richness was bidirectionally regulated by proportions and amounts of NPK. Ascomycota was the dominant fungal phylum in ginseng rhizosphere soil, and relative abundances decreased with combined NPK application. Combined NPK application increased the relative abundance of potential beneficial fungi, such as Mortierella, but decreased that of potentially pathogenic fungi, such as Fusarium. Correlation analysis showed that potential beneficial fungi were significantly positively correlated with ginseng rhizome yield and ginsenoside contents, whereas the opposite relation was observed with potential pathogenic fungi. Thus, in addition to directly increasing crop growth, precise NPK application can also increase crop adaptability to the environment by shaping specific microbial communities. The results of this study suggest that the combined effects of biotic and abiotic processes on agricultural production determine crop yield and quality.
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