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

2017 ◽  
pp. 33 ◽  
Author(s):  
Sara Lucía Camargo-Ricalde

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.

1995 ◽  
Vol 73 (S1) ◽  
pp. 1284-1290 ◽  
Author(s):  
Peter Jeffries

The term mycoparasitism applies strictly to those relationships in which one living fungus acts as a nutrient source for another, but fungicolous relationships may also be included in which nutrient exchange has not been shown. Fungicolous fungi have a constant but indeterminate association with another fungus, and it can be difficult to demonstrate a true parasitic relationship. Mycoparasitic relationships can be necrotrophic or biotrophic, and can be classified on the basis of the host–parasite interface as contact necrotrophs, invasive necrotrophs, haustorial biotrophs, intracellular biotrophs, or fusion biotrophs depending on the intimacy of the relationship. In natural ecosystems, it is proposed that mycoparasitic relationships play an important role in the development of fungal communities. Two specific examples have been chosen to illustrate the general principles of mycoparasitism: the necrotrophic invasion of spores of arbuscular mycorrhizal fungi and the biotrophic invasion of mucoralean hosts by haustorial mycoparasites. Key words: mycoparasitism, fungicolous fungi, arbuscular mycorrhizal fungi, fungal ecology.


2021 ◽  
Vol 10 (3) ◽  
pp. 217-228
Author(s):  
Herath BMMD ◽  
Madushan KWA ◽  
Lakmali JPD ◽  
Yapa PN

Human activities have introduced large amounts of heavy metals into natural ecosystems in recent years. As a result, the accumulation of heavy metals and metalloids in plants, animals, and humans, which may have caused some health problems. Chemical and physical methods can remove the heavy metal in contaminated soil, but both are very expensive and ineffective. Arbuscular Mycorrhizal Fungi (AMF) are mutualistic symbionts in most plant roots. Furthermore, AMF are the essential mycorrhizae for phytoremediation, and the extensive hyphal network of them can increase the uptake of micro and macronutrients, water and heavy metals from the soil. However, AMF hyphae colonized in plant roots have an ability for compartmentalizing heavy metals inside plant roots. Furthermore, AMF hyphae are capable of secreting a glycoprotein, named glomalin, which can bind heavy metals and subsequently remove heavy metals absorbed by the plants from contaminated soil. Glomalin can develop the properties and structure of the soil, which helps to enhance soil fertility. This paper presents the role of AMF in the ecosystems and as potential tools for bioremediation of heavy metals in the soil.


2010 ◽  
Vol 34 (3) ◽  
pp. 765-771 ◽  
Author(s):  
Rosilda dos Santos ◽  
Carla Giovana Girardi ◽  
Rosete Pescador ◽  
Sidney Luiz Stürmer

The rhizomes of Zingiber officinale Roscoe (ginger) are widely used for their medicinal and flavoring properties, whereas the influence of root symbionts on their growth is poorly understood. In this study, the effects of phosphate fertilization and inoculation with a mixture of arbuscular mycorrhizal fungi (AMF) (isolates Glomus clarum RGS101A, Entrophospora colombiana SCT115A and Acaulospora koskei SPL102A) on survival, growth and development of micropropagated ginger were investigated. After transplanting to post vitro conditions, the ginger microplants were subjected to the following treatments: a) AMF mixture, b) P addition (25 mg kg-1), c) AMF + P, and d) non-mycorrhizal control without P addition. After eight months of growth, survival ranged from 86 to 100 % in the AMF and AMF+P treatments versus 71 % survival in control and P treatments. In the AMF, P and AMF+P treatments, the shoot, root and rhizome biomass production were significantly larger than in the control plants. In the non-mycorrhizal control plants the leaf number, leaf area, number of shoots/plants, and shoot length were significantly lower than in the AMF, P and AMF+P treatments. Root colonization ranged from 81 to 93 % and was not affected by P application. The data confirmed the response of several growth variables of micropropagated ginger to mycorrhizal colonization and P addition.


2000 ◽  
Vol 29 (1) ◽  
pp. 55-62 ◽  
Author(s):  
J.C. Dodd

Symbionts called ‘mycorrhizal fungi’ occur in most biomes on earth, and are a fundamental reason for plant growth and development on the planet. The most common group of mycorrhizal fungi is that of the arbuscular mycorrhizal fungi (AMF), which colonize the roots of over 80% of land plant families, but they cannot as yet be cultured away from the host plant. AMF are primarily responsible for nutrient transfer from soil to plant, but have other roles such as soil aggregation, protection of plants against drought stress and soil pathogens, and increasing plant diversity. This is achieved by the growth of their fungal mycelium within a host root and out into the soil beyond. There is an urgent need to study the below-ground microbiology of soils in agro-and natural ecosystems, as AMF are pivotal in closing nutrient cycles and have a proven multifunctional role in soil–plant interactions. More information is also needed on the biodiversity and functional diversity of these microbes and their interactions with crops and plants.


2019 ◽  
Author(s):  
Guru V. Radhakrishnan ◽  
Jean Keller ◽  
Melanie K. Rich ◽  
Tatiana Vernié ◽  
Duchesse L. Mbadinga Mbaginda ◽  
...  

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.


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