scholarly journals Local Adaptation to Soil Hypoxia Determines the Structure of an Arbuscular Mycorrhizal Fungal Community in Roots from Natural CO2Springs

2011 ◽  
Vol 77 (14) ◽  
pp. 4770-4777 ◽  
Author(s):  
Irena Maček ◽  
Alex J. Dumbrell ◽  
Michaela Nelson ◽  
Alastair H. Fitter ◽  
Dominik Vodnik ◽  
...  

ABSTRACTThe processes responsible for producing and maintaining the diversity of natural arbuscular mycorrhizal (AM) fungal communities remain largely unknown. We used natural CO2springs (mofettes), which create hypoxic soil environments, to determine whether a long-term, directional, abiotic selection pressure could change AM fungal community structure and drive the selection of particular AM fungal phylotypes. We explored whether those phylotypes that appear exclusively in hypoxic soils are local specialists or widespread generalists able to tolerate a range of soil conditions. AM fungal community composition was characterized by cloning, restriction fragment length polymorphism typing, and the sequencing of small subunit rRNA genes from roots of four plant species growing at high (hypoxic) and low (control) geological CO2exposure. We found significant levels of AM fungal community turnover (β diversity) between soil types and the numerical dominance of two AM fungal phylotypes in hypoxic soils. Our results strongly suggest that direct environmental selection acting on AM fungi is a major factor regulating AM fungal communities and their phylogeographic patterns. Consequently, some AM fungi are more strongly associated with local variations in the soil environment than with their host plant's distribution.

Agronomy ◽  
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

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.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 361
Author(s):  
Clara P. Peña-Venegas ◽  
Armando Sterling ◽  
Tatiana K. Andrade-Ramírez

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.


2020 ◽  
Author(s):  
Li Ji ◽  
Yan Zhang ◽  
Yuchun Yang ◽  
Lixue Yang ◽  
Na Yang ◽  
...  

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.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Li Ji ◽  
Yan Zhang ◽  
Yuchun Yang ◽  
Lixue Yang ◽  
Na Yang ◽  
...  

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nini Lu ◽  
Xuelei Xu ◽  
Ping Wang ◽  
Peng Zhang ◽  
Baoming Ji ◽  
...  

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.


2014 ◽  
Vol 60 (9) ◽  
pp. 619-624 ◽  
Author(s):  
P.-L. Chagnon ◽  
L.D. Bainard

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.


2006 ◽  
Vol 84 (10) ◽  
pp. 1617-1627 ◽  
Author(s):  
Tesfaye Wubet ◽  
Michael Weiß ◽  
Ingrid Kottke ◽  
Franz Oberwinkler

The molecular diversity of arbuscular mycorrhizal (AM) fungi colonizing roots of Podocarpus falcatus (Thunb.) R.Br. (Podocarpaceae) in the dry Afromontane forests of Ethiopia was investigated. The nuclear gene coding for small subunit ribosomal RNA (nucSSU rDNA) was amplified from colonized roots of P. falcatus, cloned, and sequenced using AM fungal specific primers. Phylogenetic analyses revealed that the glomeromycetous sequences from mycorrhizae of P. falcatus belong to the Glomeraceae, Diversisporaceae, and Archaeosporaceae. Overall, 16 Glomus , three Diversispora , and one Archaeospora sequence types were identified. These sequence types were distinct and only distantly related to sequences from the available defined species. The composition of the AM fungal communities differed significantly between the two study sites. Comparison of the AM fungal community composition of P. falcatus with that of previously investigated Juniperus procera Hochst. ex Endl. (Cupressaceae), the only coexisting indigenous conifer tree species in the dry Afromontane forest ecosystem, yields that the two tree species are colonized by distinct AM fungal communities. This suggests that fungal communities are host plant specific in the natural stand conditions. Therefore, in the conservation of these endangered species and restoration of the degraded ecosystem, the use of appropriate mycorrhizal fungi should be taken into account in future projects.


2020 ◽  
Author(s):  
Adam Frew ◽  
Bree A. L. Wilson

ABSTRACTArbuscular mycorrhizal (AM) fungi are ubiquitous symbionts of most terrestrial plants. These fungi not only provide their host plants with access to nutrients and resources but are known to augment plant defences against insect herbivores. Relatively little is known about the role of AM fungal diversity and community assembly on the expression of plant defence traits. Here, we report how plant (Triticum aestivum) phenolic-based resistance to insect herbivory is differentially affected by different AM fungal communities. An inoculant of four AM fungal species and a field-sourced native AM fungal community increased plant phenolics by 47.9% and 50.2%, respectively, compared to plants inoculated with only one fungal species. Correspondingly, the performance (relative growth rate) of the insect herbivore was 36% and 61.3% lower when feeding on plants associated with these AM fungal communities. Furthermore, there was a negative correlation between foliar phenolics and herbivore growth. We propose that AM fungal community assembly can drive insect herbivore performance by affecting phenolic-based defence mechanisms.


2018 ◽  
Vol 64 (8) ◽  
pp. 527-536 ◽  
Author(s):  
Walid Ellouze ◽  
Chantal Hamel ◽  
Asheesh K. Singh ◽  
Vachaspati Mishra ◽  
Ron M. DePauw ◽  
...  

Understanding the variation in how wheat genotypes shape their arbuscular mycorrhizal (AM) fungal communities in a prairie environment is foundational to breeding for enhanced AM fungi–wheat interactions. The AM fungal communities associated with 32 durum wheat genotypes were described by pyrosequencing of amplicons. The experiment was set up at two locations in the Canadian prairies. The intensively managed site was highly dominated by Funneliformis. Genotype influenced the AM fungal community in the rhizosphere soil, but there was no evidence of a differential genotype effect on the AM fungal community of durum wheat roots. The influence of durum wheat genotype on the AM fungal community of the soil was less important at the intensively managed site. Certain durum wheat genotypes, such as Strongfield, Plenty, and CDC Verona, were associated with high abundance of Paraglomus, and Dominikia was undetected in the rhizosphere of the recent cultivars Enterprise, Eurostar, Commander, and Brigade. Genetic variation in the association of durum wheat with AM fungi suggests the possibility of increasing the sustainability of cropping systems through the use of durum wheat genotypes that select highly effective AM fungal taxa residing in the agricultural soils of the Canadian prairies.


2007 ◽  
Vol 73 (17) ◽  
pp. 5613-5623 ◽  
Author(s):  
Juan C. Santos-González ◽  
Roger D. Finlay ◽  
Anders Tehler

ABSTRACT Symbiotic arbuscular mycorrhizal fungi (AMF) have been shown to influence both the diversity and productivity of grassland plant communities. These effects have been postulated to depend on the differential effects of individual mycorrhizal taxa on different plant species; however, so far there are few detailed studies of the dynamics of AMF colonization of different plant species. In this study, we characterized the communities of AMF colonizing the roots of two plant species, Prunella vulgaris and Antennaria dioica, in a Swedish seminatural grassland at different times of the year. The AMF small subunit rRNA genes were subjected to PCR, cloning, sequencing, and phylogenetic analysis. Nineteen discrete sequence types belonging to Glomus groups A and B and to the genus Acaulospora were distinguished. No significant seasonal changes in the species compositions of the AMF communities as a whole were observed. However, the two plant species hosted significantly different AMF communities. P. vulgaris hosted a rich AMF community throughout the entire growing season. The presence of AMF in A. dioica decreased dramatically in autumn, while an increased presence of Ascomycetes species was detected.


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