Non-symbiotic soil microbes are more strongly influenced by altered tree biodiversity than arbuscular mycorrhizal fungi during initial forest establishment

ABSTRACT While the relationship between plant and microbial diversity has been well studied in grasslands, less is known about similar relationships in forests, especially for obligately symbiotic arbuscular mycorrhizal (AM) fungi. To assess the effect of varying tree diversity on microbial alpha- and beta-diversity, we sampled soil from plots in a high-density tree diversity experiment in Minnesota, USA, 3 years after establishment. About 3 of 12 tree species are AM hosts; the other 9 primarily associate with ectomycorrhizal fungi. We used phospho- and neutral lipid fatty acid analysis to characterize the biomass and functional identity of the whole soil bacterial and fungal community and high throughput sequencing to identify the species-level richness and composition of the AM fungal community. We found that plots of differing tree composition had different bacterial and fungal communities; plots with conifers, and especially Juniperus virginiana, had lower densities of several bacterial groups. In contrast, plots with a higher density or diversity of AM hosts showed no sign of greater AM fungal abundance or diversity. Our results indicate that early responses to plant diversity vary considerably across microbial groups, with AM fungal communities potentially requiring longer timescales to respond to changes in host tree diversity.

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Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

10.32942/osf.io/t82ug ◽

2019 ◽

Cited By ~ 1

Author(s):

Coline Deveautour ◽

Sally Power ◽

Kirk Barnett ◽

Raul Ochoa-Hueso ◽

Suzanne Donn ◽

...

Keyword(s):

Community Composition ◽

Plant Community ◽

Plant Communities ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Temporal Dynamics ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Plant Responses ◽

Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

Journal of Lipids ◽

10.1155/2012/236807 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 43

Author(s):

Christopher Ngosong ◽

Elke Gabriel ◽

Liliane Ruess

Keyword(s):

Fatty Acid ◽

Mycorrhizal Fungi ◽

Plant Root ◽

Background Level ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Biomass Estimation ◽

Lipid Fatty Acid ◽

Neutral Lipid Fatty Acid ◽

Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

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Novel Approach to Study the Diversity of Soil Microbial Communities in Qatar

University of the Future: Re-Imagining Research and Higher Education ◽

10.29117/quarfe.2020.0025 ◽

2020 ◽

Author(s):

Jane Oja ◽

Sakeenah Adenan ◽

Abdel-Fattah Talaat ◽

Juha Alatalo

Keyword(s):

Microbial Communities ◽

High Throughput ◽

Mycorrhizal Fungi ◽

High Throughput Sequencing ◽

Soil Microbial Communities ◽

Arbuscular Mycorrhizal ◽

Soil Microbial ◽

Fungal Abundance ◽

Novel Approach ◽

Soil Climate

A broad diversity of microorganisms can be found in soil, where they are essential for nutrient cycling and energy transfer. Recent high-throughput sequencing methods have greatly advanced our knowledge about how soil, climate and vegetation variables structure the composition of microbial communities in many world regions. However, we are lacking information from several regions in the world, e.g. Middle-East. We have collected soil from 19 different habitat types for studying the diversity and composition of soil microbial communities (both fungi and bacteria) in Qatar and determining which edaphic parameters exert the strongest influences on these communities. Preliminary results indicate that in overall bacteria are more abundant in soil than fungi and few sites have notably higher abundance of these microbes. In addition, we have detected some soil patameters, which tend to have reduced the overall fungal abundance and enhanced the presence of arbuscular mycorrhizal fungi and N-fixing bacteria. More detailed information on the diversity and composition of soil microbial communities is expected from the high-throughput sequenced data.

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Fertilization effects on the fungal biomass in grasslands

10.5194/egusphere-egu2020-16110 ◽

2020 ◽

Author(s):

Ana Barreiro ◽

Aaron Fox ◽

Andreas Lüscher ◽

Franco Widmer ◽

Linda-Maria Dimitrova Mårtersson

Keyword(s):

Nitrogen Fertilization ◽

Mycorrhizal Fungi ◽

Fungal Biomass ◽

Field Experiments ◽

Production Systems ◽

Arbuscular Mycorrhizal ◽

Fatty Acid Analysis ◽

N Fertilization ◽

Lipid Fatty Acid ◽

Neutral Lipid Fatty Acid

Fertilisation is a common practise in grass production systems performed to increase primary production, a supporting ecosystem service essential for other services. However, different fungal groups, like saprothropic fungi (SF) and the obligate symbionts arbuscular mycorrhizal fungi (AMF), have potential differential response to the fertilizer concentration and composition. Three controlled field experiments were utilised in our study, two medium-term (6 years) in the south of Sweden (SE) and one long-term experiment (46 year) in Switzerland (CH), all sampled in 2018. The Swedish sites included the same two factor treatment, i.e. four different plant mixtures and two (SE-Lanna) or three (SE-Alnarp) nitrogen fertilization levels (0, 60, 120 kg ha-1 yr-1); while the Swiss experiment&#160; included different proportions of N, P and K fertilization under different cutting regimes (CH-Bremgarten). The PLFA and NLFA (phospholipid- and neutral lipid fatty acid) analysis was used to estimate the fungal biomass (SF+AMF). The application of N was associated with a decrease in the AMF biomass, with significant effects with the application of 60 and 120 kg N ha-1 in SE-Alnarp, and 75 and 150 kg N ha-1 in CH-Bremgarten. On the other hand, the SF biomass was only negatively affected by the N fertilization in SE-Lanna (60 kg N ha-1) under the plant mixture that showed the biggest SF biomass in the unfertilized plot; and by the highest application of N in CH-Bremgarten. Our findings indicate that nitrogen fertilization influences microbial community structure and reduces the abundance of AMF, with these being more sensitive than SF to fertilizer application.

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13C Incorporation into Signature Fatty Acids as an Assay for Carbon Allocation in Arbuscular Mycorrhiza

Applied and Environmental Microbiology ◽

10.1128/aem.71.5.2592-2599.2005 ◽

2005 ◽

Vol 71 (5) ◽

pp. 2592-2599 ◽

Cited By ~ 41

Author(s):

Pål Axel Olsson ◽

Ingrid M. van Aarle ◽

Mayra E. Gavito ◽

Per Bengtson ◽

Göran Bengtsson

Keyword(s):

Fatty Acid ◽

Arbuscular Mycorrhizal Fungi ◽

Neutral Lipid ◽

Mycorrhizal Fungi ◽

Carbon Allocation ◽

Arbuscular Mycorrhizal ◽

Extraradical Mycelium ◽

Lipid Fatty Acid ◽

Neutral Lipid Fatty Acid ◽

Carbon Transfer

ABSTRACT The ubiquitous arbuscular mycorrhizal fungi consume significant amounts of plant assimilated C, but this C flow has been difficult to quantify. The neutral lipid fatty acid 16:1ω5 is a quantitative signature for most arbuscular mycorrhizal fungi in roots and soil. We measured carbon transfer from four plant species to the arbuscular mycorrhizal fungus Glomus intraradices by estimating 13C enrichment of 16:1ω5 and compared it with 13C enrichment of total root and mycelial C. Carbon allocation to mycelia was detected within 1 day in monoxenic arbuscular mycorrhizal root cultures labeled with [13C]glucose. The 13C enrichment of neutral lipid fatty acid 16:1ω5 extracted from roots increased from 0.14% 1 day after labeling to 2.2% 7 days after labeling. The colonized roots usually were more enriched for 13C in the arbuscular mycorrhizal fungal neutral lipid fatty acid 16:1ω5 than for the root specific neutral lipid fatty acid 18:2ω6,9. We labeled plant assimilates by using 13CO2 in whole-plant experiments. The extraradical mycelium often was more enriched for 13C than was the intraradical mycelium, suggesting rapid translocation of carbon to and more active growth by the extraradical mycelium. Since there was a good correlation between 13C enrichment in neutral lipid fatty acid 16:1ω5 and total 13C in extraradical mycelia in different systems (r 2 = 0.94), we propose that the total amount of labeled C in intraradical and extraradical mycelium can be calculated from the 13C enrichment of 16:1ω5. The method described enables evaluation of C flow from plants to arbuscular mycorrhizal fungi to be made without extraction, purification and identification of fungal mycelia.

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Response of soil fungal communities to continuous cropping of flue-cured tobacco

Scientific Reports ◽

10.1038/s41598-020-77044-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Shengnan Wang ◽

Jiangke Cheng ◽

Tong Li ◽

Yuncheng Liao

Keyword(s):

Community Structure ◽

Fungal Community ◽

High Throughput Sequencing ◽

Cropping Systems ◽

Quantitative Polymerase Chain Reaction ◽

Fungal Communities ◽

Continuous Cropping ◽

Fungal Community Structure ◽

Soil Variables ◽

Fungal Abundance

AbstractFungal communities are considered to be critically important for crop health and soil fertility. However, our knowledge of the response of fungal community structure to the continuous cropping of flue-cured tobacco is limited, and the interaction of soil fungal communities under different cropping systems remains unclear. In this study, we comparatively investigated the fungal abundance, diversity, and community composition in the soils in which continuous cropping of flue-cured tobacco for 3 years (3ys), 5 years (5ys), and cropping for 1 year (CK) using quantitative polymerase chain reaction and high-throughput sequencing technology. The results revealed that continuous cropping of flue-cured tobacco changed the abundance of soil fungi, and caused a significant variation in fungal diversity. In particular, continuous cropping increased the relative abundance of Mortierellales, which can dissolve mineral phosphorus in soil. Unfortunately, continuous cropping also increased the risk of potential pathogens. Moreover, long-term continuous cropping had more complex and stabilize network. This study also indicated that available potassium and available phosphorous were the primary soil factors shifting the fungal community structure. These results suggested that several soil variables may affect fungal community structure. The continuous cropping of flue-cured tobacco significantly increased the abundance and diversity of soil fungal communities.

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Parasitism to mutualism continuum for Joshua trees inoculated with different communities of arbuscular mycorrhizal fungi from a desert elevation gradient

PLoS ONE ◽

10.1371/journal.pone.0256068 ◽

2021 ◽

Vol 16 (8) ◽

pp. e0256068

Author(s):

Jennifer T. Harrower ◽

Gregory S. Gilbert

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Species Interactions ◽

High Throughput Sequencing ◽

Abiotic Factors ◽

Elevation Gradient ◽

Arbuscular Mycorrhizal ◽

Fungal Communities ◽

Climate Gradient ◽

Joshua Trees

Most desert plants form symbiotic relationships with arbuscular mycorrhizal fungi (AMF), yet fungal identity and impacts on host plants remain largely unknown. Despite widespread recognition of the importance of AMF relationships for plant functioning, we do not know how fungal community structure changes across a desert climate gradient, nor the impacts of different fungal communities on host plant species. Because climate change can shape the distribution of species through effects on species interactions, knowing how the ranges of symbiotic partners are geographically structured and the outcomes of those species interactions informs theory and improves management recommendations. Here we used high throughput sequencing to examine the AMF community of Joshua trees along a climate gradient in Joshua Tree National Park. We then used a range of performance measures and abiotic factors to evaluate how different AMF communities may affect Joshua tree fitness. We found that fungal communities change with elevation resulting in a spectrum of interaction outcomes from mutualism to parasitism that changed with the developmental stage of the plant. Nutrient accumulation and the mycorrhizal growth response of Joshua tree seedlings inoculated with fungi from the lowest (warmest) elevations was first negative, but after 9 months had surpassed that of plants with other fungal treatments. This indicates that low elevation fungi are costly for the plant to initiate symbiosis, yet confer benefits over time. The strong relationship between AMF community and plant growth suggests that variation in AMF community may have long term consequences for plant populations along an elevation gradient.

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Changes in Soil-Borne Communities of Arbuscular Mycorrhizal Fungi during Natural Regrowth of Abandoned Cattle Pastures Are Indicative of Ecosystem Restoration

Agronomy ◽

10.3390/agronomy11122468 ◽

2021 ◽

Vol 11 (12) ◽

pp. 2468

Author(s):

Carlos H. Rodríguez-León ◽

Clara P. Peña-Venegas ◽

Armando Sterling ◽

Herminton Muñoz-Ramirez ◽

Yeny R. Virguez-Díaz

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Small Subunit ◽

Fungal Communities ◽

Small Subunit Rrna ◽

Fungal Community Composition ◽

Natural Restoration ◽

Degraded Pastures

Natural restoration of ecosystems includes the restoration of plant-microbial associations; however, few studies had documented those changes in tropical ecosystems. With the aim to contribute to understand soil microbial changes in a natural regrowth succession of degraded pastures that were left for natural restoration, we studied changes in arbuscular mycorrhizal (AM) fungal communities. Arbuscular mycorrhizal fungi (AMF) establish a mutualistic symbiosis with plants, improving plant nutrition. Amplification of the small subunit rRNA with specific primers and subsequent Illumina sequencing were used to search soil-borne AM fungal communities in four successional natural regrowth stages in two landscapes (hill and mountain) with soil differences, located in the Andean-Amazonian transition. Molecular results corroborated the results obtained previously by spores-dependent approaches. More abundance and virtual taxa of AMF exist in the soil of degraded pastures and early natural regrowth stages than in old-growth or mature forest soils. Although changes in AM fungal communities occurred similarly over the natural regrowth chronosequence, differences in soil texture between landscapes was an important soil feature differentiating AM fungal community composition and richness. Changes in soil-borne AM fungal communities reflect some signals of environmental restoration that had not been described before, such as the reduction of Glomus dominance and the increase of Paraglomus representativeness in the AM fungal community during the natural regrowth chronosequence.

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Fungal community assembly in soils and roots under plant invasion and nitrogen deposition

10.1101/416818 ◽

2018 ◽

Author(s):

Michala L. Phillips ◽

S□ren E. Weber ◽

Lela V. Andrews ◽

Emma L. Aronson ◽

Michael F. Allen ◽

...

Keyword(s):

Fungal Community ◽

Mycorrhizal Fungi ◽

Native Species ◽

Arbuscular Mycorrhizal ◽

N Deposition ◽

Fungal Communities ◽

Atmospheric Nitrogen ◽

Annual Grass ◽

Fungal Community Composition ◽

Rapid Changes

AbstractAbstract Fungal community composition in the Anthropocene is driven by rapid changes in environmental conditions caused by human activities. This study examines the relative importance of two global change drivers – atmospheric nitrogen (N) deposition and annual grass invasion – on structuring fungal communities in a California chaparral ecosystem, with emphasis on arbuscular mycorrhizal fungi. We used molecular markers, functional groupings, generalized linear statistics and joint distribution modeling, to examine how environmental variables structure taxonomic and functional composition of fungal communities. Invasion of a chaparral ecosystem decreased richness and relative abundance of non-AMF symbionts and rhizophilic AMF (e.g. Glomeraceae) as well as the proportion of edaphophilic AMF (e.g. Gigasporaceae). We found increased richness and the proportion of rhizophilic and edaphophilic AMF with increasing soil NO3. Our findings suggest that invasive persistence may decrease the presence of multiple soil symbionts that native species depend on for pathogen protection and increased access to soil resources.

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Metabarcoding of Soil Fungal Communities from Perturbed Areas Reveal Drive Role of Environmental Factors in Microbial Diversity of Colombian Andosols

10.21203/rs.3.rs-1128776/v1 ◽

2021 ◽

Author(s):

RAUL ALEXANDER ARANGUREN AROCA ◽

Samuele Voyron ◽

Fabrizio Ungaro ◽

Julio Cañón ◽

Erica Lumini

Keyword(s):

Land Use ◽

Fungal Community ◽

Mycorrhizal Fungi ◽

Alpha Diversity ◽

Arbuscular Mycorrhizal ◽

Conservation Agriculture ◽

Illumina Miseq ◽

Fungal Communities ◽

Its2 Region ◽

Fungal Community Composition

Abstract Changes in soil fungal community caused by land use have not been sufficiently studied in South-American Andosols, considered globally as important food production areas. This study analyzed 26 soil samples of Andosols collected from locations devoted to conservation, agriculture and mining activities in the southeastern region of Antioquia, Colombia, to establish differences between fungal communities as indicators of the degree of soil perturbation. The study developed a novel heminested PCR with primers SSUmCf Mix, ITS4 and fITS7 to assess Arbuscular Mycorrhizal Fungi detection in a Illumina MiSeq metabarcoding on nuclear ribosomal ITS2 region. A non-metric multidimensional scaling allowed exploring driver factors of fungal community changes, while fitted Dirichlet-multinomial models and PERMANOVA tests allowed identifying the correlations between alpha diversity indexes and community dissimilarities, as well as the significance of land use effects on fungal community composition. Furthermore, response ratios were determined to assess effect size by land use over relevant taxa. Results suggest a good coverage of fungal diversity with a detection of 10,529 high-quality ITS2 sequences belonged to phylum Glomeromycota. The analysis shows strong correlations of Shannon and Fisher indexes with dissimilarities on fungal communities among land uses (r=0.94), related to variations in temperature, air humidity and organic matter contents that lead to significant responses in abundances of relevant orders (such as Wallemiales and Trichosporonales). The study highlights the rich fungal biodiversity of the tropical Andosols, their specific sensitivities to environmental perturbation factors, and the useful range of a metabarcoding approach to characterize soil fungal communities.

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