Resource limitation is a driver of local adaptation in mycorrhizal symbioses

Symbioses may be important mechanisms of plant adaptation to their environment. We conducted a reciprocal inoculation experiment to test the hypothesis that soil fertility is a key driver of local adaptation in arbuscular mycorrhizal (AM) symbioses. Ecotypes ofAndropogon gerardiifrom phosphorus-limited and nitrogen-limited grasslands were grown with all possible “home and away” combinations of soils and AM fungal communities. Our results indicate thatAndropogonecotypes adapt to their local soil and indigenous AM fungal communities such that mycorrhizal exchange of the most limiting resource is maximized. Grasses grown in home soil and inoculated with home AM fungi produced more arbuscules (symbiotic exchange structures) in their roots than those grown in away combinations. Also, regardless of the host ecotype, AM fungi produced more extraradical hyphae in their home soil, and locally adapted AM fungi were, therefore, able to sequester more carbon compared with nonlocal fungi. Locally adapted mycorrhizal associations were more mutualistic in the two phosphorus-limited sites and less parasitic at the nitrogen-limited site compared with novel combinations of plants, fungi, and soils. To our knowledge, these findings provide the strongest evidence to date that resource availability generates evolved geographic structure in symbioses among plants and soil organisms. Thus, edaphic origin of AM fungi should be considered when managing for their benefits in agriculture, ecosystem restoration, and soil-carbon sequestration.

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Long-term Effects of Mixed Planting on Arbuscular Mycorrhizal Fungal Communities in the Roots and Soils of Juglans mandshurica Plantations

10.21203/rs.3.rs-36133/v2 ◽

2020 ◽

Author(s):

Li Ji ◽

Yan Zhang ◽

Yuchun Yang ◽

Lixue Yang ◽

Na Yang ◽

...

Keyword(s):

Fungal Community ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Soil Samples ◽

Fungal Communities ◽

Juglans Mandshurica ◽

Mixed Plantations ◽

Mixed Plantation ◽

Unique Otus

Abstract Background: Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management.Results: Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil.Conclusions: Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

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Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils

Plant Disease ◽

10.1094/pdis-10-10-0741 ◽

2011 ◽

Vol 95 (8) ◽

pp. 960-966 ◽

Cited By ~ 114

Author(s):

Wade H. Elmer ◽

Joseph J. Pignatello

Keyword(s):

Root Rot ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

First Year ◽

Root Weight ◽

Fusarium Spp ◽

Biomass Waste ◽

Mycorrhizal Associations ◽

Crown And Root Rot

Pyrolyzed biomass waste, commonly called biochar, has attracted interest as a soil amendment. A commercial prototype biochar produced by fast pyrolysis of hardwood dust was examined in soils to determine if it could reduce the damaging effect of allelopathy on arbuscular mycorrhizal (AM) root colonization and on Fusarium crown and root rot of asparagus. In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to asparagus field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium oxysporum f. sp. asparagi and F. proliferatum compared with a control. Concomitant with these effects was a 100% increase in root colonization by AM fungi at the 3.0% rate. Addition of aromatic acids (cinnamic, coumaric, and ferulic) that are known allelopathic agents affecting asparagus reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate. When dried, ground, asparagus root and crown tissues infested with Fusarium spp. were added to soilless potting mix at 0, 1, or 5 g/liter of potting mix and then planted with asparagus, there was a decrease in asparagus root weight and increase in disease at 1 g/liter of potting mix but results were inconsistent at the higher residue rate. However, when biochar was added at 35 g/liter of potting mix (roughly 10%, vol/vol), these adverse effects on root weight and disease were equal to the nontreated controls. A small demonstration was conducted in field microplots. Those plots amended with biochar (3.5% [wt/wt] soil) produced asparagus plants with more AM colonization in the first year of growth but, in the subsequent year, biochar-treated plants were reduced in size, possibly due to greater than average precipitation and the ability of biochar to retain moisture that, in turn, may have created conditions conducive to root rot. These studies provide evidence that biochar may be useful in overcoming the deleterious effects of allelopathic residues in replant soils on asparagus.

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Arbuscular mycorrhizal fungal succession in a long-lived perennial

Botany ◽

10.1139/cjb-2013-0185 ◽

2014 ◽

Vol 92 (4) ◽

pp. 313-320 ◽

Cited By ~ 16

Author(s):

Miranda M. Hart ◽

Monika Gorzelak ◽

Diane Ragone ◽

Susan J. Murch

Keyword(s):

High Throughput Sequencing ◽

Selective Pressure ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Fungal Communities ◽

Artocarpus Altilis ◽

Host Identity ◽

Arbuscular Mycorrhizal Fungal ◽

Insight Into

It is difficult to understand why arbuscular mycorrhizal (AM) fungal communities change over time. The role of host identity confounds our understanding of successional changes in AM fungal communities because hosts exert strong selective pressure on their root-associated microbes. In this study we looked at the AM fungi associated with a long-lived perennial breadfruit (Artocarpus altilis (Parkinson) Fosberg) to see how AM communities change over the life span of a single, long-lived host. Using 454 high-throughput sequencing, we found evidence that older trees had more AM fungal taxa than younger trees and were associated with different AM fungal communities, but these differences were not apparent early in the life cycle. Older trees were dominated by species of Rhizophagus, whereas younger trees and genets were dominated by species of Glomus. Some taxa were only detected in older trees (e.g., Funneliformis) or genets (e.g., Racocetra and Scutellospora), indicating that certain AM fungal taxa may serve as “indicators” of the successional age of the fungal community. These results provide important information about a poorly studied system and give insight into how AM communities change over longer time scales.

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Anthropogenic Disturbance Impacts Mycorrhizal Communities and Abiotic Soil Properties: Implications for an Endemic Forest Disease

Frontiers in Forests and Global Change ◽

10.3389/ffgc.2020.593243 ◽

2021 ◽

Vol 3 ◽

Author(s):

Sarah J. Sapsford ◽

Trudy Paap ◽

Giles E. St. J. Hardy ◽

Treena I. Burgess

Keyword(s):

Soil Properties ◽

Soil Nutrients ◽

Large Scale ◽

Stand Structure ◽

Disease Incidence ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Illumina Miseq ◽

Fungal Communities ◽

Canker Disease

In forest ecosystems, habitat fragmentation negatively impacts stand structure and biodiversity; the resulting fragmented patches of forest have distinct, disturbed edge habitats that experience different environmental conditions than the interiors of the fragments. In southwest Western Australia, there is a large-scale decline of the keystone tree species Corymbia calophylla following fragmentation and land use change. These changes have altered stand structure and increased their susceptibility to an endemic fungal pathogen, Quambalaria coyrecup, which causes chronic canker disease especially along disturbed forest habitats. However, the impacts of fragmentation on belowground processes in this system are not well-understood. We examined the effects of fragmentation on abiotic soil properties and ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungal communities, and whether these belowground changes were drivers of disease incidence. We collected soil from 17 sites across the distribution range of C. calophylla. Soils were collected across a gradient from disturbed, diseased areas to undisturbed, disease-free areas. We analysed soil nutrients and grew C. calophylla plants as a bioassay host. Plants were harvested and roots collected after 6 months of growth. DNA was extracted from the roots, amplified using fungal specific primers and sequenced using Illumina MiSeq. Concentrations of key soil nutrients such as nitrogen, phosphorus and potassium were much higher along the disturbed, diseased edges in comparison to undisturbed areas. Disturbance altered the community composition of ECM and AM fungi; however, only ECM fungal communities had lower rarefied richness and diversity along the disturbed, diseased areas compared to undisturbed areas. Accounting for effects of disturbance, ECM fungal diversity and leaf litter depth were highly correlated with increased disease incidence in C. calophylla. In the face of global change, increased virulence of an endemic pathogen has emerged in this Mediterranean-type forest.

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Long-term effects of mixed planting on arbuscular mycorrhizal fungal communities in the roots and soils of Juglans mandshurica plantations

BMC Microbiology ◽

10.1186/s12866-020-01987-1 ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Li Ji ◽

Yan Zhang ◽

Yuchun Yang ◽

Lixue Yang ◽

Na Yang ◽

...

Keyword(s):

Fungal Community ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Soil Samples ◽

Fungal Communities ◽

Juglans Mandshurica ◽

Mixed Plantations ◽

Mixed Plantation ◽

Unique Otus

Abstract Background Establishing mixed plantations is an effective way to improve soil fertility and increase forest productivity. Arbuscular mycorrhizal (AM) fungi are obligate symbiotic fungi that can promote mineral nutrient absorption and regulate intraspecific and interspecific competition in plants. However, the effects of mixed plantations on the community structure and abundance of AM fungi are still unclear. Illumina MiSeq sequencing was used to investigate the AM fungal community in the roots and soils of pure and mixed plantations (Juglans mandshurica × Larix gmelinii). The objective of this study is to compare the differential responses of the root and rhizosphere soil AM fungal communities of Juglans mandshurica to long-term mixed plantation management. Results Glomus and Paraglomus were the dominant genera in the root samples, accounting for more than 80% of the sequences. Compared with that in the pure plantation, the relative abundance of Glomus was higher in the mixed plantation. Glomus, Diversispora and Paraglomus accounted for more than 85% of the sequences in the soil samples. The relative abundances of Diversispora and an unidentified genus of Glomeromycetes were higher and lower in the pure plantation, respectively. The Root_P samples (the roots in the pure plantation) had the highest number of unique OTUs (operational taxonomic units), which belonged mainly to an unidentified genus of Glomeromycetes, Paraglomus, Glomus and Acaulospora. The number of unique OTUs detected in the soil was lower than that in the roots. In both the root and soil samples, the forest type did not have a significant effect on AM fungal diversity, but the Sobs value and the Shannon, Chao1 and Ace indices of AM fungi in the roots were significantly higher than those in the soil. Conclusions Mixed forest management had little effect on the AM fungal community of Juglans mandshurica roots and significantly changed the community composition of the soil AM fungi, but not the diversity.

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Impact of Land Use on Arbuscular Mycorrhizal Fungal Communities in Rural Canada

Applied and Environmental Microbiology ◽

10.1128/aem.01333-13 ◽

2013 ◽

Vol 79 (21) ◽

pp. 6719-6729 ◽

Cited By ~ 41

Author(s):

Mulan Dai ◽

Luke D. Bainard ◽

Chantal Hamel ◽

Yantai Gan ◽

Derek Lynch

Keyword(s):

Land Use ◽

Species Richness ◽

Diversity Index ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

18S Rrna Gene ◽

Fungal Communities ◽

Rrna Gene ◽

Canadian Prairie ◽

Highly Correlated

ABSTRACTThe influence of land use on soil bio-resources is largely unknown. We examined the communities of arbuscular mycorrhizal (AM) fungi in wheat-growing cropland, natural areas, and seminatural areas along roads. We sampled the Canadian prairie extensively (317 sites) and sampled 20 sites in the Atlantic maritime ecozone for comparison. The proportions of the different AM fungal taxa in the communities found at these sites varied with land use type and ecozones, based on pyrosequencing of 18S rRNA gene (rDNA) amplicons, but the lists of AM fungal taxa obtained from the different land use types and ecozones were very similar. In the prairie, the Glomeraceae family was the most abundant and diverse family of Glomeromycota, followed by the Claroideoglomeraceae, but in the Atlantic maritime ecozone, the Claroideoglomeraceae family was most abundant. In the prairie, species richness and Shannon's diversity index were highest in roadsides, whereas cropland had a higher degree of species richness than roadsides in the Atlantic maritime ecozone. The frequencies of occurrence of the different AM fungal taxa in croplands in the prairie and Atlantic maritime ecozones were highly correlated, but the AM fungal communities in these ecozones had different structures. We conclude that the AM fungal resources of soils are resilient to disturbance and that the richness of AM fungi under cropland management has been maintained, despite evidence of a structural shift imposed by this type of land use. Roadsides in the Canadian prairie are a good repository for the conservation of AM fungal diversity.

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Nutritional effects of indigenous arbuscular mycorrhizal associations on the sclerophyllous species <i>Agathosma betulina</i>

Web Ecology ◽

10.5194/we-7-77-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 77-86 ◽

Cited By ~ 5

Author(s):

K. J. Cloete ◽

A. J. Valentine ◽

L. M. Blomerus ◽

A. Botha ◽

M. A. Pèrez-Fernández

Keyword(s):

Food Additives ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

P Uptake ◽

Ribosomal Gene ◽

Early Stages ◽

Seedling Physiology ◽

Mycorrhizal Associations ◽

Growth Respiration ◽

Arbuscular Mycorrhizal Associations

Abstract. Relatively little is currently known about the seedling physiology of arbuscular mycorrhizal (AM) Agathosma betulina, a sclerophyllous crop plant cultivated for its high-value essential oils and food additives. In addition, virtually nothing is known about the AM associations of this plant. Consequently, the effect of an indigenous community of AM fungi on P nutrition and C economy in seedlings, grown in nursery conditions, was determined during different stages of host and AM fungal establishment. AM fungal ribosomal gene sequence analyses were used to identify some of the fungi within the roots, responsible for the nutritional changes. During the early stages of host and AM fungal establishment (0 to 77 days after germination), host growth was reduced, whereas the rate of P-uptake and growth respiration was increased. Beyond 77 days of growth, the rate of P-uptake and growth respiration declined. These findings, together with results obtained after molecular analyses of root associated fungal DNA, indicate that AM fungi belonging to the genera Acaulospora and Glomus, improve P-uptake and costs of utilization during the early stages of seedling establishment in a nutrient-poor soil.

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Succession in arbuscular mycorrhizal fungi can be attributed to a chronosequence of Cunninghamia lanceolata

Scientific Reports ◽

10.1038/s41598-019-54452-z ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Nini Lu ◽

Xuelei Xu ◽

Ping Wang ◽

Peng Zhang ◽

Baoming Ji ◽

...

Keyword(s):

Host Plant ◽

Fungal Community ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Chinese Fir ◽

Fungal Communities ◽

Available P ◽

Total N ◽

Available N ◽

Significant Difference

AbstractArbuscular mycorrhizal (AM) fungi play an important role in plant-fungi communities. It remains a central question of how the AM fungal community changes as plants grow. To establish an understanding of AM fungal community dynamics associated with Chinese fir, Chinese fir with five different growth stages were studied and 60 root samples were collected at the Jiangle National Forestry Farm, Fujian Province. A total of 76 AM fungal operational taxonomic units (OTUs) were identified by high-throughput sequencing on an Illumina Miseq platform. The genera covered by OTUs were Glomus, Archaeospora, Acaulospora, Gigaspora and Diversispora. Glomus dominated the community in the whole stage. The number and composition of OTUs varied along with the host plant growth. The number of OTUs showed an inverted V-shaped change with the host plant age, and the maximum occurred in 23-year. Overall, the basic species diversity and richness in this study were stable. Non-metric multi-dimensional scaling (NMDS) analysis based on bray-curtis distance revealed that there were remarkable differentiations between the 9-year and other stages. Besides, AM fungal community in 32-year had a significant difference with that of 23-year, while no significant difference with that of 45-year, suggesting that 32-year may be a steady stage for AM fungi associated with Chinese fir. The cutting age in 32-year may be the most favorable for microbial community. The pH, total N, total P, total K, available N, available P, available K, organic matter and Mg varied as the Chinese fir grows. According to Mantel test and redundancy analysis, available N, available P, K and Mg could exert significant influence on AM fungal communities, and these variables explained 31% of variance in the composition of AM fungal communities.

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Is root DNA a reliable proxy to assess arbuscular mycorrhizal community structure?

Canadian Journal of Microbiology ◽

10.1139/cjm-2014-0235 ◽

2014 ◽

Vol 60 (9) ◽

pp. 619-624 ◽

Cited By ~ 3

Author(s):

P.-L. Chagnon ◽

L.D. Bainard

Keyword(s):

Community Structure ◽

Fungal Community ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Molecular Data ◽

Fungal Communities ◽

Published Data ◽

Data Sets ◽

Fungal Community Structure ◽

Arbuscular Mycorrhizal Community

Arbuscular mycorrhizal (AM) fungi are widespread plant symbionts that extensively colonize both soil and roots. Given their influence on ecosystem processes, such as plant growth, soil carbon storage, and nutrient cycling, there is great interest in understanding the drivers of their community structure. AM fungal communities are increasingly characterized by selectively amplifying their DNA from plant roots, thus assuming that AM fungal community structure within roots provides a reliable portrait of the total (i.e., soil + roots) community. Through numerical simulations, we test this assumption using published data. We show that community structure and diversity is well preserved when analyzing only a subset of the community biomass (i.e., roots or soil), provided that the community shows a typical skewed abundance distribution, with few very dominant species and a high prevalence of rare species. Given that this community structure has been shown to be common in natural AM fungal communities, the present work would suggest that characterizing AM fungal communities using only roots or soil can provide a reliable portrait of the overall community. However, we show through additional analyses that the proportion of sample biomass used for molecular methods must be over a minimal threshold to properly characterize the community. Using published molecular data sets, we validate those results, which suggest that typical molecular protocols using low amounts of biomass may strongly influence AM fungal community characterization. Finally, we also discuss other assumptions implied by the molecular analysis of AM fungal communities, and point out urgent knowledge gaps.

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Arbuscular Mycorrhization in Colombian and Introduced Rubber (Hevea brasiliensis) Genotypes Cultivated on Degraded Soils of the Amazon Region

Agriculture ◽

10.3390/agriculture11040361 ◽

2021 ◽

Vol 11 (4) ◽

pp. 361

Author(s):

Clara P. Peña-Venegas ◽

Armando Sterling ◽

Tatiana K. Andrade-Ramírez

Keyword(s):

Fungal Community ◽

Hevea Brasiliensis ◽

Plant Nutrition ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Molecular Techniques ◽

Fungal Communities ◽

Fungal Community Composition ◽

Am Symbiosis

Rubber (Hevea brasiliensis, (Willd. Ex Adr. de Juss) Muell. Arg, Euphorbiaceae) is an important commercial latex-producing plant. Commercially, rubber is reproduced from a limited number of grifting genotypes. New promising genotypes have been selected to replace traditional genotypes. In addition, rubber has been promoted to recuperate Amazon soils degraded by extensive cattle ranching. Arbuscular mycorrhizal (AM) symbiosis is an important alternative for improving plant nutrition in rubber trees and recuperating degraded soils, but AM fungal communities on different plantations and in rubber genotypes are unknown. Spore abundance, root colonization and AM fungal community composition were evaluated in rubber roots of Colombian and introduced genotypes cultivated in degraded soils with different plantation types. Traditional (spore isolation and description; clearing and staining roots) and molecular techniques (Illumina sequencing) were used to assess AM fungi. Rubber roots hosted a diverse AM fungal community of 135 virtual taxa (VT) in 13 genera. The genus Glomus represented 66% of the total AM fungal community. Rubber genotype did not affect the arbuscular mycorrhization, hosting similar AM fungal communities. The composition of the AM fungal community on old and young rubber plantations was different. Diversity in AM fungi in rubber roots is an important characteristic for restoring degraded soils.

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