scholarly journals Observations on Antagonism in the Arbuscular Mycorrhizal Systems

Author(s):  
Taher Y. Abourghiba

Abstract: The majority of land plants are colonised by arbuscular mycorrhizal fungi, however ,members of few families notably Cruciferae, Chenopodiaceae, Caryophyllaceae and Polygonaceae, so called non-host are not colonized by these fungi. Previous studies have shown that the growth and development of non-host species were severely inhibited when grown in the presence of active AMF mycelia. There is therefore a need to understand the mechanistic bases of adverse effects of AMF mycelia upon seedlings of non-host species. In this experiment young roots of non-hosts Spergula arvensis and Arabis hirsuta, and host Centaurium erythraea were exposed to mycorrhizal and non-mycorrhizal extracts. The results of this experiment showed that mycorrhizal extracts significantly reduced the growth of radicles and root hairs development of non-host species whereas had no effect on radicles and root hairs development of host species. These results indicate that toxicity effects rather the nutritional factors are the drivers of the negative responses of non-host species to the presence of the AMF. Keywords: mycorrhizal fungi, host and non-host plants, Plantago lanceolata , Glomus mossae , mycelium

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 370
Author(s):  
Murugesan Chandrasekaran

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts of higher plants which increase the growth and nutrient uptake of host plants. The primary objective was initiated based on analyzing the enormity of optimal effects upon AMF inoculation in a comparative bias between mycorrhizal and non-mycorrhizal plants stipulated on plant biomass and nutrient uptake. Consequently, in accomplishing the above-mentioned objective a vast literature was collected, analyzed, and evaluated to establish a weighted meta-analysis irrespective of AMF species, plant species, family and functional group, and experimental conditions in the context of beneficial effects of AMF. I found a significant increase in the shoot, root, and total biomass by 36.3%, 28.5%, and, 29.7%, respectively. Moreover, mycorrhizal plants significantly increased phosphorus, nitrogen, and potassium uptake by 36.3%, 22.1%, and 18.5%, respectively. Affirmatively upon cross-verification studies, plant growth parameters intensification was accredited to AMF (Rhizophagus fasciculatus followed by Funniliforme mosseae), plants (Triticum aestivum followed by Solanum lycopersicum), and plant functional groups (dicot, herbs, and perennial) were the additional vital important significant predictor variables of plant growth responses. Therefore, the meta-analysis concluded that the emancipated prominent root characteristics, increased morphological traits that eventually help the host plants for efficient phosphorus uptake, thereby enhancing plant biomass. The present analysis can be rationalized for any plant stress and assessment of any microbial agent that contributes to plant growth promotion.


2015 ◽  
Vol 7 (3) ◽  
pp. 233-243 ◽  
Author(s):  
Rafiq Lone ◽  
Razia Shuab ◽  
Vandna Sharma ◽  
Vijay Kumar ◽  
Rayees Mir ◽  
...  

2005 ◽  
Vol 71 (11) ◽  
pp. 6673-6679 ◽  
Author(s):  
David Roesti ◽  
Kurt Ineichen ◽  
Olivier Braissant ◽  
Dirk Redecker ◽  
Andres Wiemken ◽  
...  

ABSTRACT Spores of the arbuscular mycorrhizal fungi (AMF) Glomus geosporum and Glomus constrictum were harvested from single-spore-derived pot cultures with either Plantago lanceolata or Hieracium pilosella as host plants. PCR-denaturing gradient gel electrophoresis analysis revealed that the bacterial communities associated with the spores depended more on AMF than host plant identity. The composition of the bacterial populations linked to the spores could be predominantly influenced by a specific spore wall composition or AMF exudate rather than by specific root exudates. The majority of the bacterial sequences that were common to both G. geosporum and G. constrictum spores were affiliated with taxonomic groups known to degrade biopolymers (Cellvibrio, Chondromyces, Flexibacter, Lysobacter, and Pseudomonas). Scanning electron microscopy of G. geosporum spores revealed that these bacteria are possibly feeding on the outer hyaline spore layer. The process of maturation and eventual germination of AMF spores might then benefit from the activity of the surface microorganisms degrading the outer hyaline wall layer.


Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1468
Author(s):  
Nieves Goicoechea

The association that many crops can establish with the arbuscular mycorrhizal fungi (AMF) present in soils can enhance the resistance of the host plants against several pathogens, including Verticillium spp. The increased resistance of mycorrhizal plants is mainly due to the improved nutritional and water status of crops and to enhanced antioxidant metabolism and/or increased production of secondary metabolites in the plant tissues. However, the effectiveness of AMF in protecting their host plants against Verticillium spp. may vary depending on the environmental factors. Some environmental factors, such as the concentration of carbon dioxide in the atmosphere, the availability of soil water and the air and soil temperatures, are predicted to change drastically by the end of the century. The present paper discusses to what extent the climate change may influence the role of AMF in protecting crops against Verticillium-induced wilt, taking into account the current knowledge about the direct and indirect effects that the changing environment can exert on AMF communities in soils and on the symbiosis between crops and AMF, as well as on the development, incidence and impact of diseases caused by soil-borne pathogens.


Botany ◽  
2009 ◽  
Vol 87 (4) ◽  
pp. 387-400 ◽  
Author(s):  
Christine Juge ◽  
Annie Champagne ◽  
Andrew P. Coughlan ◽  
Nicolas Juge ◽  
Lael Parrott ◽  
...  

The present study is, to the best of our knowledge, the first to investigate the use of the fractal dimension (FD) to quantify the growth and development of undisturbed, fully functional arbuscular mycorrhizal (AM) hyphae developing in vitro. The majority of the work focused on the model AM fungus Glomus intraradices DAOM 181602. The time course study and final measurements of an intact mature extraradical mycelium allowed us to compare the development of the mycelium and the FD value. The final FD value of 1.62 for the mature mycelium is similar to that obtained for highly branched root systems and tree crowns. The FD method was used to characterize the morphology of germinative and presymbiotic hyphae in the presence of stimulatory (strigolactone GR-24, 0.1 µmol·L–1 and bisphenol A, 10 µmol·L–1) and inhibitory (NaCl, 80 mmol·L–1) molecules, and the extraradical phase in the presence of an inhibitory molecule (NaCl, 80 mmol·L–1). Where possible, results were compared with those obtained using the traditional grid-line (GL) technique. The FD approach allowed treatment effects to be accurately quantified, both in germinative and extraradical phases. In the second case, this technique provided a single quantitative value of extraradical hyphal growth that included runner hyphae (RH) networks, and fine-branching (FB) ramifications. This is in contrast to the GL technique, which provides a value for the estimation of RH, but which is not suitable for accurately measuring FB hyphae. Given the ease with which the FD values can be calculated, and the fact that this method can provide a single value for the quantification of extraradical hyphal growth and development, we suggest that this method is useful for in vitro studies. Furthermore under certain situations of germinative or presymbiotic growth, it may be used in concert with the GL method to provide a greater degree of information about hyphal morphology. The usefulness and limits of the FD method at different stages of the AM fungal growth cycle are discussed.


2015 ◽  
Vol 396 (1-2) ◽  
pp. 369-380 ◽  
Author(s):  
Haiyang Zhang ◽  
Waldemar Ziegler ◽  
Xingguo Han ◽  
Susan Trumbore ◽  
Henrik Hartmann

2000 ◽  
Vol 18 (4) ◽  
pp. 247-251
Author(s):  
F.T. Davies ◽  
J.A. Saraiva Grossi ◽  
L. Carpio ◽  
A.A. Estrada-Luna

Abstract The objectives of this research were to demonstrate that mycorrhiza can survive in a commercial nursery container production system, and enhance plant productivity. Four species were used as host plants [Nandina domestica ‘Moon Bay’, Loropetalum chinense variety Rubrum ‘Hinepurpleleaf’ Plumb delight®, Salvia gregii, and Photinia fraseri]. Plants were inoculated with arbuscular mycorrhizal fungi, Glomus intraradices, and grown in a commercial nursery in Texas. For the first 5.5 months, plants were grown in #1 cans containing either 3 kg cu m (5 lbs cu yd) or 4.2 kg cu m (7 lbs cu yd) 24N–4P205–8K20. For the final 6.5 months of the study, plants were in larger containers, all of which contained 4.2 kg cu m (7 lbs cu yd) 24N–4P2O5–8K2O. The commercial inoculum of Glomus intraradices only enhanced growth of N. domestica. The shoot dry mass of mycorrhizal N. domestica plants at 3 kg cu m was the same as non-colonized plants at the higher fertility level of 4.2 cu m. Intraradical hyphae development and colonization (total arbuscules, vesicles/endospores, hyphae) of L. chinense, N. domestica, and S. gregii increased at the higher fertility levels. S. gregii had the greatest mycorrhizal development and a 216% increase in hyphae development and colonization at the higher fertility level.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qiang Dong ◽  
Xin Guo ◽  
Keyu Chen ◽  
Shijie Ren ◽  
Muhammad Atif Muneer ◽  
...  

Plants and arbuscular mycorrhizal fungi (AMF) can form complex symbiotic networks based on functional trait selection, contributing to the maintenance of ecosystem biodiversity and stability. However, the selectivity of host plants on AMF and the characteristics of plant-AMF networks remain unclear in Tibetan alpine meadows. In this study, we studied the AMF communities in 69 root samples from 23 plant species in a Tibetan alpine meadow using Illumina-MiSeq sequencing of the 18S rRNA gene. The results showed a significant positive correlation between the phylogenetic distances of plant species and the taxonomic dissimilarity of their AMF community. The plant-AMF network was characterized by high connectance, high nestedness, anti-modularity, and anti-specialization, and the phylogenetic signal from plants was stronger than that from AMF. The high connected and nested plant-AMF network potentially promoted the interdependence and stability of the plant-AMF symbioses in Tibetan alpine meadows. This study emphasizes that plant phylogeny and plant-AMF networks play an important role in the coevolution of host plants and their mycorrhizal partners and enhance our understanding of the interactions between aboveground and belowground communities.


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