scholarly journals Modularity Reveals the Tendency of Arbuscular Mycorrhizal Fungi To Interact Differently with Generalist and Specialist Plant Species in Gypsum Soils

2014 ◽  
Vol 80 (17) ◽  
pp. 5457-5466 ◽  
Author(s):  
Emma Torrecillas ◽  
Maria del Mar Alguacil ◽  
Antonio Roldán ◽  
Gisela Díaz ◽  
Alicia Montesinos-Navarro ◽  
...  

ABSTRACTPatterns in plant–soil biota interactions could be influenced by the spatial distribution of species due to soil conditions or by the functional traits of species. Gypsum environments usually constitute a mosaic of heterogeneous soils where gypsum and nongypsum soils are imbricated at a local scale. A case study of the interactions of plants with arbuscular mycorrhizal fungi (AMF) in gypsum environments can be illustrative of patterns in biotic interactions. We hypothesized that (i) soil characteristics might affect the AMF community and (ii) there are differences between the AMF communities (modules) associated with plants exclusive to gypsum soils (gypsophytes) and those associated with plants that show facultative behavior on gypsum and/or marly-limestone soils (gypsovags). We used indicator species and network analyses to test for differences between the AMF communities harbored in gypsophyte and gypsovag plants. We recorded 46 operational taxonomic units (OTUs) belonging to nine genera ofGlomeromycota. The indicator species analysis showed two OTUs preferentially associating with gypsum soils and three OTUs preferentially associating with marly-limestone soils. Modularity analysis revealed that soil type can be a major factor shaping AMF communities, and some AMF groups showed a tendency to interact differently with plants that had distinct ecological strategies (gypsophytes and gypsovags). Characterization of ecological networks can be a valuable tool for ascertaining the potential influence of above- and below-ground biotic interactions (plant-AMF) on plant community composition.

2016 ◽  
Vol 82 (11) ◽  
pp. 3348-3356 ◽  
Author(s):  
Maria del Mar Alguacil ◽  
Maria Pilar Torres ◽  
Alicia Montesinos-Navarro ◽  
Antonio Roldán

ABSTRACTWe investigated communities of arbuscular mycorrhizal fungi (AMF) in the roots and the rhizosphere soil ofBrachypodium retusumin six different natural soils under field conditions. We explored phylogenetic patterns of AMF composition using indicator species analyses to find AMF associated with a given habitat (root versus rhizosphere) or soil type. We tested whether the AMF characteristics of different habitats or contrasting soils were more closely related than expected by chance. Then we used principal-component analysis and multivariate analysis of variance to test for the relative contribution of each factor in explaining the variation in fungal community composition. Finally, we used redundancy analysis to identify the soil properties that significantly explained the differences in AMF communities across soil types. The results pointed out a tendency of AMF communities in roots to be closely related and different from those in the rhizosphere soil. The indicator species analyses revealed AMF associated with rhizosphere soil and the root habitat. Soil type also determined the distribution of AMF communities in soils, and this effect could not be attributed to a single soil characteristic, as at least three soil properties related to microbial activity, i.e., pH and levels of two micronutrients (Mn and Zn), played significant roles in triggering AMF populations.IMPORTANCECommunities of arbuscular mycorrhizal fungi (AMF) are main components of soil biota that can determine the productivity of ecosystems. These fungal assemblages vary across host plants and ecosystems, but the main ecological processes that shape the structures of these communities are still largely unknown. A field study in six different soil types from semiarid areas revealed that AMF communities are significantly influenced by habitat (soil versus roots) and soil type. In addition, three soil properties related to microbiological activity (i.e., pH and manganese and zinc levels) were the main factors triggering the distribution of AMF. These results contribute to a better understanding of the ecological factors that can shape AMF communities, an important soil microbial group that affects multiple ecosystem functions.


2014 ◽  
Vol 49 (4) ◽  
pp. 521-540 ◽  
Author(s):  
Hana Pánková ◽  
Zuzana Münzbergová ◽  
Jana Rydlová ◽  
Miroslav Vosátka

2011 ◽  
Vol 77 (24) ◽  
pp. 8656-8661 ◽  
Author(s):  
Maria del Mar Alguacil ◽  
Emma Torrecillas ◽  
Zenaida Lozano ◽  
Antonio Roldán

ABSTRACTArbuscular mycorrhizal fungi (AMF) play important roles as plant protection agents, reducing or suppressing nematode colonization. However, it has never been investigated whether the galls produced in roots by nematode infection are colonized by AMF. This study tested whether galls produced byMeloidogyne incognitainfection inPrunus persicaroots are colonized by AMF. We also determined the changes in AMF composition and biodiversity mediated by infection with this root-knot nematode. DNA from galls and roots of plants infected byM. incognitaand from roots of noninfected plants was extracted, amplified, cloned, and sequenced using AMF-specific primers. Phylogenetic analysis using the small-subunit (SSU) ribosomal DNA (rDNA) data set revealed 22 different AMF sequence types (17Glomussequence types, 3Paraglomussequence types, 1Scutellosporasequence type, and 1Acaulosporasequence type). The highest AMF diversity was found in uninfected roots, followed by infected roots and galls. This study indicates that the galls produced inP. persicaroots due to infection withM. incognitawere colonized extensively by a community of AMF, belonging to the families Paraglomeraceae and Glomeraceae, that was different from the community detected in roots. Although the function of the AMF in the galls is still unknown, we hypothesize that they act as protection agents against opportunistic pathogens.


Mycorrhiza ◽  
2019 ◽  
Vol 29 (6) ◽  
pp. 551-565 ◽  
Author(s):  
William R. Rimington ◽  
Silvia Pressel ◽  
Jeffrey G. Duckett ◽  
Katie J. Field ◽  
Martin I. Bidartondo

Abstract Like the majority of land plants, liverworts regularly form intimate symbioses with arbuscular mycorrhizal fungi (Glomeromycotina). Recent phylogenetic and physiological studies report that they also form intimate symbioses with Mucoromycotina fungi and that some of these, like those involving Glomeromycotina, represent nutritional mutualisms. To compare these symbioses, we carried out a global analysis of Mucoromycotina fungi in liverworts and other plants using species delimitation, ancestral reconstruction, and network analyses. We found that Mucoromycotina are more common and diverse symbionts of liverworts than previously thought, globally distributed, ancestral, and often co-occur with Glomeromycotina within plants. However, our results also suggest that the associations formed by Mucoromycotina fungi are fundamentally different because, unlike Glomeromycotina, they may have evolved multiple times and their symbiotic networks are un-nested (i.e., not forming nested subsets of species). We infer that the global Mucoromycotina symbiosis is evolutionarily and ecologically distinctive.


Weed Science ◽  
2019 ◽  
Vol 67 (6) ◽  
pp. 689-701
Author(s):  
Xiaoge Han ◽  
Changchao Xu ◽  
Yutao Wang ◽  
Dan Huang ◽  
Qiang Fan ◽  
...  

AbstractWeed invasion is a prevailing problem in modestly managed lawns. Less attention has been given to the exploration of the role of arbuscular mycorrhizal fungi (AMF) under different invasion pressures from lawn weeds. We conducted a four-season investigation into a Zoysia tenuifolia Willd. ex Thiele (native turfgrass)–threeflower beggarweed [Desmodium triflorum (L.) DC.] (invasive weed) co-occurring lawn. The root mycorrhizal colonizations of the two plants, the soil AM fungal communities and the spore densities under five different coverage levels of D. triflorum were investigated. Desmodium triflorum showed significantly higher root hyphal and vesicular colonizations than those of Z. tenuifolia, while the root colonizations of both species varied significantly among seasons. The increased coverage of D. triflorum resulted in the following effects: (1) the spore density initially correlated with mycorrhizal colonizations of Z. tenuifolia but gradually correlated with those of D. triflorum. (2) Correlations among soil properties, spore densities, and mycorrhizal colonizations were more pronounced in the higher coverage levels. (3) Soil AMF community compositions and relative abundances of AMF operational taxonomic units changed markedly in response to the increased invasion pressure. The results provide strong evidence that D. triflorum possessed a more intense AMF infection than Z. tenuifolia, thus giving rise to the altered host contributions to sporulation, soil AMF communities, relations of soil properties, spore densities, and root colonizations of the two plants, all of which are pivotal for the successful invasion of D. triflorum in lawns.


1997 ◽  
Vol 75 (2) ◽  
pp. 320-332 ◽  
Author(s):  
R. E. Koske ◽  
J. N. Gemma ◽  
N. Jackson

Small plots of highly maintained turfs of creeping bentgrass (Agrostis palustris cv. Penncross) and velvet bentgrass (Agrostis canina cv. Kingstown) and a marginally maintained stand of annual bluegrass (Poa annua) were sampled intensively over a 15-month period to measure the populations of spores of arbuscular mycorrhizal fungi (AMF) associated with their root systems. Direct isolation of spores and trap cultures were used to assess the AMF communities. Spores of more than 18 species of AMF were isolated. The six dominant species (as measured by the abundance and frequency of occurrence of spores) were Acaulospora mellea, an undescribed species of Acaulospora, Scutellospora calospora, Glomus occultum, Glomus etunicatum, and Entrophospora infrequens. Spores of 17 species of AMF were recovered from the root zones of velvet bentgrass, 15 species from creeping bentgrass, and 14 from annual bluegrass. Soil fertility differed among the three sites, and it was not possible to ascribe differences in the AMF communities in each plot to any particular variable (e.g., host, pH, soil P). Average spore abundance was greatest in the creeping bentgrass plot (191.0 spores/100 mL), next in the velvet bentgrass plot (82.4 spores/100 mL), and least in the bluegrass plot (28.4 spores/100 mL). Spores were recovered from a significantly greater percentage of the samples from the bentgrass plots (88.5 – 96.8%) than from the bluegrass plot (76.6%). Spores of an average of 4.5 species of AMF were isolated monthly from creeping bentgrass, 3.3 from velvet bentgrass and 2.0 from bluegrass. Average species richness and spore abundance were positively correlated in the creeping bentgrass and bluegrass plots (r = 0.77, p = 0.001, and r = 0.68, p = 0.006), but not in the velvet bentgrass plot. Spore abundance showed strong seasonal trends in all three plots (p = 0.03 – 0.001), with numbers increasing from spring until November. Richness and abundance declined from December until the following spring. In the bluegrass area, which experienced summer drought, spore populations and richness also showed a precipitous decline in July and August in the 1st year of the study (1990), but not in the 2nd year (1991). No such summer decline occurred in the bentgrass plots that received irrigation. The AMF community that was circumscribed by direct spore counts from the field usually was highly dissimilar to the community that was estimated by trap cultures initiated using soil from the turf areas. Key words: annual bluegrass, arbuscular mycorrhizal fungi, creeping bentgrass, putting greens, turfgrass, velvet bentgrass.


Author(s):  
Yuying Ma ◽  
Huanchao Zhang ◽  
Daozhong Wang ◽  
Xisheng Guo ◽  
Teng Yang ◽  
...  

Arbuscular mycorrhizal fungi (AMF) provide essential nutrients to crops and are critically impacted by fertilization in agricultural ecosystems. Understanding shifts in AMF communities in and around crop roots under different fertilization regimes can provide important lessons for improving agricultural production and sustainability. Here, we compared the responses of AMF communities in the rhizosphere (RS) and root endosphere (ES) of wheat ( Triticum aestivum ) to different fertilization treatments: Non-fertilization (Control), mineral fertilization only (NPK), mineral fertilization plus wheat straw (NPKS), and mineral fertilization plus cow manure (NPKM). We employed high-throughput amplicon sequencing and investigated the diversity, community composition, and network structure of AMF communities to assess their responses to fertilization. Our results elucidated that AMF communities in the RS and ES respond differently to fertilization schemes. Long-term NPK application decreased the RS AMF alpha diversity significantly, whereas additional organic amendments (straw or manure) had no effect. Contrastingly, NPK fertilization increased the ES AMF alpha diversity significantly, while additional organic amendments decreased it significantly. The effect of different fertilization schemes on AMF network complexity in the RS and ES were similar to their effects on alpha diversity. Changes to AMF communities in the RS and ES correlated mainly with the pH and phosphorus level of the rhizosphere soil under long-term inorganic and organic fertilization regimes. We suggest that the AMF community in the roots should be given more consideration when studying the effects of fertilization regimes on AMF in agroecosystems. Importance Arbuscular mycorrhizal fungi are an integral component of rhizospheres, bridging the soil and plant systems and are highly sensitive to fertilization. However, surprisingly little is known about how the response differs between the roots and the surrounding soil. Decreasing arbuscular mycorrhizal fungal diversity under fertilization has been reported, implying a potential reduction in the mutualism between plants and arbuscular mycorrhizal fungi. However, we found opposing responses to long-term fertilization managements of arbuscular mycorrhizal fungi in the wheat roots and rhizosphere soil. These results suggested that changes in the arbuscular mycorrhizal fungal community in soils do not reflect those in the roots, highlighting that the root arbuscular mycorrhizal fungal community is pertinent to understand arbuscular mycorrhizal fungi and their crop hosts’ responses to anthropogenic influences.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marie- Noëlle Binet ◽  
Camille Marchal ◽  
Justine Lipuma ◽  
Roberto A. Geremia ◽  
Olivier Bagarri ◽  
...  

AbstractWe investigated root communities of arbuscular mycorrhizal fungi (AMF) in relation to lavender (Lavandula angustifolia) and lavandin (Lavandula intermedia) health status from organic and conventional fields affected by Phytoplasma infection. The intensity of root mycorrhizal colonization was significantly different between diseased and healthy plants and was higher in the latter regardless of agricultural practice. This difference was more pronounced in lavender. The root AMF diversity was influenced by the plant health status solely in lavender and only under the conventional practice resulting in an increase in the AMF abundance and richness. The plant health status did not influence the distribution of root AMF communities in lavandin unlike its strong impact in lavender in both agricultural practices. Finally, among the most abundant molecular operational taxonomic units (MOTUs), four different MOTUs for each plant species were significantly abundant in the roots of healthy lavender and lavandin in either agricultural practice. Our study demonstrated that the plant health status influences root colonization and can influence the diversity and distribution of root AMF communities. Its effects vary according to plant species, can be modified by agricultural practices and allow plants to establish symbiosis with specific AMF species.


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