scholarly journals An ancestral signalling pathway is conserved in plant lineages forming intracellular symbioses

2019 ◽  
Author(s):  
Guru V. Radhakrishnan ◽  
Jean Keller ◽  
Melanie K. Rich ◽  
Tatiana Vernié ◽  
Duchesse L. Mbadinga Mbaginda ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Ecosystems ◽  
Signalling Pathway ◽  
Bacterial Symbionts ◽  
Orchid Mycorrhizae ◽  
The Common ◽  
Colonization Of Land ◽  
Plant Diversification

ABSTRACTPlants are the foundation of terrestrial ecosystems and their colonization of land was facilitated by mutualistic associations with arbuscular mycorrhizal fungi. Following that founding event, plant diversification has led to the emergence of a tremendous diversity of mutualistic symbioses with microorganisms, ranging from extracellular associations to the most intimate intracellular associations, where fungal or bacterial symbionts are hosted inside plant cells. Through analysis of 271 transcriptomes and 122 plant genomes, we demonstrate that the common symbiosis signalling pathway controlling the association with arbuscular mycorrhizal fungi and with nitrogen-fixing bacteria specifically co-evolved with intracellular endosymbioses, including ericoid and orchid mycorrhizae in angiosperms and ericoid-like associations of bryophytes. In contrast, species forming exclusively extracellular symbioses like ectomycorrhizae or associations with cyanobacteria have lost this signalling pathway. This work unifies intracellular symbioses, revealing conservation in their evolution across 450 million years of plant diversification.

scholarly journals Potential Effects of Microplastic on Arbuscular Mycorrhizal Fungi

2021 ◽  
Vol 12 ◽  
Author(s):  
Eva F. Leifheit ◽  
Anika Lehmann ◽  
Matthias C. Rillig
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Net Primary Production ◽  
Soil Aggregates ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Ecosystems ◽  
Root Diameter ◽  
Future Research ◽  
Soil Parameters ◽  
The Impact

Microplastics (MPs) are ubiquitously found in terrestrial ecosystems and are increasingly recognized as a factor of global change (GCF). Current research shows that MP can alter plant growth, soil inherent properties, and the composition and activity of microbial communities. However, knowledge about how microplastic affects arbuscular mycorrhizal fungi (AMF) is scarce. For plants it has been shown that microplastic can both increase and decrease the aboveground biomass and reduce the root diameter, which could indirectly cause a change in AMF abundance and activity. One of the main direct effects of microplastic is the reduction of the soil bulk density, which translates to an altered soil pore structure and water transport. Moreover, especially fibers can have considerable impacts on soil structure, namely the size distribution and stability of soil aggregates. Therefore, microplastic alters a number of soil parameters that determine habitat space and conditions for AMF. We expect that this will influence functions mediated by AMF, such as soil aggregation, water and nutrient transport. We discuss how the impacts of microplastic on AMF could alter how plants deal with other GCFs in the context of sustainable food production. The co-occurrence of several GCFs, e.g., elevated temperature, drought, pesticides, and microplastic could modify the impact of microplastic on AMF. Furthermore, the ubiquitous presence of microplastic also relates to earth system processes, e.g., net primary production (NPP), carbon and nitrogen cycling, which involve AMF as key soil organisms. For future research, we outline which experiments should be prioritized.

Lipid exchanges drove the evolution of mutualism during plant terrestrialization

Science ◽  
2021 ◽  
Vol 372 (6544) ◽  
pp. 864-868
Author(s):  
Mélanie K. Rich ◽  
Nicolas Vigneron ◽  
Cyril Libourel ◽  
Jean Keller ◽  
Li Xue ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Plant Nutrition ◽  
Arbuscular Mycorrhizal ◽  
Land Plants ◽  
Loss Of Function ◽  
Transcriptomic Response ◽  
Marchantia Paleacea ◽  
Colonization Of Land ◽  
Direct Regulation

Symbiosis with arbuscular mycorrhizal fungi (AMF) improves plant nutrition in most land plants, and its contribution to the colonization of land by plants has been hypothesized. Here, we identify a conserved transcriptomic response to AMF among land plants, including the activation of lipid metabolism. Using gain of function, we show the transfer of lipids from the liverwort Marchantia paleacea to AMF and its direct regulation by the transcription factor WRINKLED (WRI). Arbuscules, the nutrient-exchange structures, were not formed in loss-of-function wri mutants in M. paleacea, leading to aborted mutualism. Our results show the orthology of the symbiotic transfer of lipids across land plants and demonstrate that mutualism with arbuscular mycorrhizal fungi was present in the most recent ancestor of land plants 450 million years ago.

scholarly journals No Significant Contribution of Arbuscular Mycorrhizal Fungi to Transfer of Radiocesium from Soil to Plants

2004 ◽  
Vol 70 (11) ◽  
pp. 6512-6517 ◽  
Author(s):  
E. J. Joner ◽  
P. Roos ◽  
J. Jansa ◽  
E. Frossard ◽  
C. Leyval ◽  
...  
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Food Chain ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Biogeochemical Cycling ◽  
Terrestrial Ecosystems ◽  
Mineral Elements ◽  
Human Food ◽  
Human Food Chain ◽  
Symbiotic Fungi

ABSTRACT The diffuse pollution by fission and activation products following nuclear accidents and weapons testing is of major public concern. Among the nuclides that pose a serious risk if they enter the human food chain are the cesium isotopes 137Cs and 134Cs (with half-lives of 30 and 2 years, respectively). The biogeochemical cycling of these isotopes in forest ecosystems is strongly affected by their preferential absorption in a range of ectomycorrhiza-forming basidiomycetes. An even more widely distributed group of symbiotic fungi are the arbuscular mycorrhizal fungi, which colonize most herbaceous plants, including many agricultural crops. These fungi are known to be more efficient than ectomycorrhizas in transporting mineral elements from soil to plants. Their role in the biogeochemical cycling of Cs is poorly known, in spite of the consequences that fungal Cs transport may have for transfer of Cs into the human food chain. This report presents the first data on transport of Cs by these fungi by use of radiotracers and compartmented growth systems where uptake by roots and mycorrhizal hyphae is distinguished. Independent experiments in three laboratories that used different combinations of fungi and host plants all demonstrated that these fungi do not contribute significantly to plant uptake of Cs. The implications of these findings for the bioavailability of radiocesium in different terrestrial ecosystems are discussed.

scholarly journals Mosaic genome of endobacteria in arbuscular mycorrhizal fungi: Transkingdom gene transfer in an ancient mycoplasma-fungus association

2015 ◽  
Vol 112 (25) ◽  
pp. 7785-7790 ◽  
Author(s):  
Gloria Torres-Cortés ◽  
Stefano Ghignone ◽  
Paola Bonfante ◽  
Arthur Schüßler
Keyword(s):  
Gene Transfer ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Phylogenetic Analyses ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Ecosystems ◽  
Genomic Islands ◽  
Fungal Host ◽  
Functional Roles ◽  
Almost All

For more than 450 million years, arbuscular mycorrhizal fungi (AMF) have formed intimate, mutualistic symbioses with the vast majority of land plants and are major drivers in almost all terrestrial ecosystems. The obligate plant-symbiotic AMF host additional symbionts, so-called Mollicutes-related endobacteria (MRE). To uncover putative functional roles of these widespread but yet enigmatic MRE, we sequenced the genome of DhMRE living in the AMF Dentiscutata heterogama. Multilocus phylogenetic analyses showed that MRE form a previously unidentified lineage sister to the hominis group of Mycoplasma species. DhMRE possesses a strongly reduced metabolic capacity with 55% of the proteins having unknown function, which reflects unique adaptations to an intracellular lifestyle. We found evidence for transkingdom gene transfer between MRE and their AMF host. At least 27 annotated DhMRE proteins show similarities to nuclear-encoded proteins of the AMF Rhizophagus irregularis, which itself lacks MRE. Nuclear-encoded homologs could moreover be identified for another AMF, Gigaspora margarita, and surprisingly, also the non-AMF Mortierella verticillata. Our data indicate a possible origin of the MRE-fungus association in ancestors of the Glomeromycota and Mucoromycotina. The DhMRE genome encodes an arsenal of putative regulatory proteins with eukaryotic-like domains, some of them encoded in putative genomic islands. MRE are highly interesting candidates to study the evolution and interactions between an ancient, obligate endosymbiotic prokaryote with its obligate plant-symbiotic fungal host. Our data moreover may be used for further targeted searches for ancient effector-like proteins that may be key components in the regulation of the arbuscular mycorrhiza symbiosis.

scholarly journals Diversity of Arbuscular Mycorrhizal Fungi in Agroforestry, Conventional Plantations and Native Forests in Roraima State, Northern Brazil

2019 ◽  
Vol 11 (14) ◽  
pp. 282 ◽  
Author(s):  
Tharles Mesquita Araújo ◽  
Krisle da Silva ◽  
Gilmara Maria Duarte Pereira ◽  
Alexandre Curcino ◽  
Sidney Luiz Stürmer ◽  
...  
Keyword(s):  
Species Richness ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Terrestrial Ecosystems ◽  
Agroforestry System ◽  
Native Forest ◽  
Amf Diversity ◽  
Amf Communities ◽  
Land Use And Management

Arbuscular mycorrhizal fungi (AMF) are important components of the soil microbiota in terrestrial ecosystems, under the influence of various factors such as soil use and management, and can be adapted to a structure and diversity of fungal communities. The aim of this survey was to evaluate the influence of different systems of land use and management on AMF diversity in the Roraima State, Brazil. We collected soil samples in agroforestry, conventional soybean planting, conventional corn and native forest. After 150 days of incubation in a greenhouse, we extracted the spores in order to evaluate AMF, volume and to determine taxonomic identification. We found 16 species of AMF and the genus Acaulospora was the most frequent, followed by Glomus. Soil under agroforestry system had the highest species richness and the native forest, the lowest. On the other hand, soybean and corn areas presented greater density values than agroforestry system and native forest. In the agroforestry system, SOM attributes, Al3+ and H + Al had influence in AMF species richness. Thus, agroforestry constitute sustainable alternative influencing AMF communities in these ecosystems.

scholarly journals Dispersal, distribution and establishment of arbuscular mycorrhizal fungi: a review

2017 ◽  
pp. 33 ◽  
Author(s):  
Sara Lucía Camargo-Ricalde
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Genetic Compatibility ◽  
Natural Ecosystems ◽  
Erosion Processes ◽  
Fungal Genetic ◽  
The Common ◽  
Root Symbionts ◽  
Animal Transport

The aim of this paper is to review and assess scientific literature relevant to arbuscular mycorrhizal fungi (AMF) population dynamics: reproduction and dispersal mechanisms, and establishment and distribution in natural ecosystems. Arbuscular mycorrhizal fungi (AMF) are obligated root symbionts with an extraordinary capacity for growing, dispersing and surviving, but their life history is not well understood yet. Although there is information concerning AMF dispersal, distribution and establishment, some data are still ambiguous and contradictory. Arbuscular mycorrhizal fungi (AMF) life cycle responds to surrounding environment but even when they only reproduce asexually, their populations encompass a high genetic and functional diversity within ecosystems. Environmental disturbances create new habitats for AMF dispersal, which can take place by root to root contact, animal transport and erosion processes. These agents are the common dispersal mechanisms of AMF in nature. Distribution of AMF is influenced mainly by the environment and soil and plant communities, but the specific AMF-host plant association is thought to be secondary because the AMF must invade and colonize any host root for establishment. Thus, inoculum density, host and fungal genetic compatibility, edaphic factors and plant-microbial activity determine the formation of mycorrhizal infections.

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