Impact of anthracene on the arbuscular mycorrhizal fungus lipid metabolism

Botany ◽  
2014 ◽  
Vol 92 (2) ◽  
pp. 173-178 ◽  
Author(s):  
M. Calonne ◽  
J. Fontaine ◽  
D. Debiane ◽  
F. Laruelle ◽  
A. Grandmougin-Ferjani ◽  
...  

Anthracene, a low-molecular-weight polycyclic aromatic hydrocarbon (PAH) originating mainly from anthropogenic activities, represents one of the major persistent organic pollutants frequently detected in polluted soils. A few studies have reported the negative effect of PAH on the main steps of the arbuscular mycorrhizal fungi (AMF) life cycle resulting from lipid peroxidation; however, little is known regarding the impact of anthracene on extraradical AMF lipid metabolism. Radiolabelling experiments showed significant decreases of [1-14C]acetate incorporation into the sterol precursors (4,4-dimethylsterols and 4α-methylsterols) and in the total phospholipids (PL) of Rhizophagus irregularis (Blaszk., Wubet, Renker & Buscot) extraradical mycelium when grown in the presence of anthracene. These findings suggested a slowing down of the sterol and total PL biosynthesis pathways in AMF treated with anthracene. The negative impact of the organic pollutant on AMF membrane lipid biosynthesis may explain the growth inhibition of the fungus after PAH exposure. This study increases the understanding of the biochemical mechanisms involved in PAH ecotoxicity on AMF.

Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 520 ◽  
Author(s):  
Thomas I. Wilkes ◽  
Douglas J. Warner ◽  
Keith G. Davies ◽  
Veronica Edmonds-Brown

Zero till cropping systems typically apply broad-spectrum herbicides such as glyphosate as an alternative weed control strategy to the physical inversion of the soil provided by cultivation. Glyphosate targets 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase in plants. There is growing evidence that this may have a detrimental impact on non-target organisms such as those present in the soil microbiome. Species of commercial importance, such as arbuscular mycorrhizal (AM) fungi that form a symbiotic relationship with plant roots are an important example. This study investigates the impact of soil cultivation and glyphosate application associated with conventional tillage (CT) and zero tillage (ZT) respectively on AM fungi populations under field and glasshouse conditions. Topsoil (<10 cm) was extracted from CT and ZT fields cropped with winter wheat, plus non-cropped control plots within the same field boundary, throughout the cropping year. Glyphosate was applied in glasshouse experiments at rates between 0 and 350 g L−1. Ergosterol, an indicator of fungal biomass, was measured using high performance liquid chromatography before and after glyphosate application. Fungal root arbuscules, an indicator of AM fungi–root symbiosis, were quantified from the roots of wheat plants. Under glasshouse conditions root arbuscules were consistently higher in wheat grown in ZT field extracted soils (P = 0.01) compared to CT. Glyphosate application however inhibited fungal biomass in both the ZT (P < 0.00001) and CT (P < 0.001) treatments. In the absence of glyphosate, the number of stained root arbuscules increased significantly. Ergosterol levels, used as a proxy for fungal biomass, remained lower in the soil post glyphosate application. The results suggest that CT has a greater negative impact on AM fungal growth than ZT and glyphosate, but that glyphosate is also detrimental to AM fungal growth and hinders subsequent population recovery.


2021 ◽  
Vol 2 (3) ◽  
pp. 1-6
Author(s):  
G. Nowo Nekou ◽  
A.-M. Sontsa-Donhoung ◽  
. Hawaou ◽  
M. Bahdjolbe ◽  
R. Tobolbaï ◽  
...  

This work aims to assess the leek-arbuscular fungus symbiosis response to the effect of cutting and light exposure on the one hand, and the impact of seedling density on this symbiosis on the other hand. Allium Porrum was grown in a container in two different trials. Four species of arbuscular mycorrhizal fungi, Glomus hoi, Scutellospora gregaria, Rhizophagus intraradices and Gigaspora margarita were used to constitute the mycorrhizal inoculum. After 150 days of growth and inoculation, a series of cuts were made on the aerial part (0% = zero cut, 50% = half cut, 100% = whole cut). Plants that had undergone these treatments were placed in shade and sun for 30 days. The leek density per bag was varied by the order of 1, 2, 3 and 4 plant (s) by the pocket density test. Results showed that for 0% of cut in the shade, the vesicle occurrence decreases from 83.33% to 52.22%, and from 90% to 25.5% for 50% of cut in the shade. On the other hand, there is a significant increase in intra-root spores for a complete cut compared to other levels of cuts. For extra-root sporulation, under light, cuts have a negative and weak effect (from -11 to -3%) while in the absence of light, cuts have significant positive effects (from +16 to +61%). Regarding seedling density, the best root colonization (90%) and biomass production (14 g) are obtained with three plants per pot, but it is rather with a density of two plants per pot that extra-root sporulation is higher (153 spores/g). Variation in light, cut level and density significantly affects the development of mycorrhizal fungi.


Plant Disease ◽  
2020 ◽  
Vol 104 (9) ◽  
pp. 2406-2410 ◽  
Author(s):  
M. L. Pawlowski ◽  
G. L. Hartman

Soybean cyst nematode (SCN, Heterodera glycines) is a widely occurring pest and the leading cause of soybean yield losses in the U.S.A. There is a need to find additional SCN management strategies as sources of SCN resistance have become less effective in managing SCN populations. Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with roots of most plants including soybean. Research has shown that AMF can reduce disease severity in plants caused by pathogens and pests, including plant parasitic nematodes. The goal of this study was to evaluate the impact of AMF on SCN cyst production, SCN juveniles in roots, and SCN egg hatching. In one experiment, all five AMF species tested (Claroideoglomus claroideum, Diversispora eburnean, Dentiscutata heterogama, Funneliformis mosseae, and Rhizophagus intraradices) reduced (P < 0.05) the number of cysts on soybean roots by 59 to 81%, compared with soybean roots not inoculated with AMF. Inoculation with F. mosseae reduced SCN J2–J3 stage juveniles in soybean roots by 60% at 7 days post inoculation. A separate experiment showed that egg hatch was reduced (P < 0.05) in the presence of F. mosseae spores and their exudates by 27% and 62%, respectively. Further research is needed to evaluate the potential usefulness of AMF in field conditions and to determine the usefulness and potential of the exudates associated with SCN hatching suppression by F. mosseae. Making AMF a more effective biological control agent would provide another management tool to reduce the negative impact of SCN on soybean production.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Anurag Chaturvedi ◽  
Joaquim Cruz Corella ◽  
Chanz Robbins ◽  
Anita Loha ◽  
Laure Menin ◽  
...  

AbstractEarly-diverging fungi (EDF) are distinct from Dikarya and other eukaryotes, exhibiting high N6-methyldeoxyadenine (6mA) contents, rather than 5-methylcytosine (5mC). As plants transitioned to land the EDF sub-phylum, arbuscular mycorrhizal fungi (AMF; Glomeromycotina) evolved a symbiotic lifestyle with 80% of plant species worldwide. Here we show that these fungi exhibit 5mC and 6mA methylation characteristics that jointly set them apart from other fungi. The model AMF, R. irregularis, evolved very high levels of 5mC and greatly reduced levels of 6mA. However, unlike the Dikarya, 6mA in AMF occurs at symmetrical ApT motifs in genes and is associated with their transcription. 6mA is heterogeneously distributed among nuclei in these coenocytic fungi suggesting functional differences among nuclei. While far fewer genes are regulated by 6mA in the AMF genome than in EDF, most strikingly, 6mA methylation has been specifically retained in genes implicated in components of phosphate regulation; the quintessential hallmark defining this globally important symbiosis.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sabaiporn Nacoon ◽  
Sanun Jogloy ◽  
Nuntavun Riddech ◽  
Wiyada Mongkolthanaruk ◽  
Jindarat Ekprasert ◽  
...  

AbstractIn this work, the effects of co-inoculation between an arbuscular mycorrhizal fungus (AMF) and a phosphate solubilizing bacteria (PSB) to promote the growth and production of sunchoke under field condition were investigated during 2016 and 2017. Four treatments were set up as follows: plants without inoculation, with AMF inoculation, with PSB inoculation and with co-inoculation of PSB and AMF. The results showed the presence of PSB and AMF colonization at the harvest stage in both years. This suggested the survival of PSB and successful AMF colonization throughout the experiments. According to correlation analysis, PSB positively affected AMF spore density and colonization rate. Also, both AMF and PSB positively correlated with growth and production of sunchoke. Co-inoculation could enhance various plant parameters. However, better results in 2016 were found in co-inoculation treatment, while AMF inoculation performed the best in 2017. All of these results suggested that our AMF and PSB could effectively promote growth and production of sunchoke under field conditions. Such effects were varied due to different environmental conditions each year. Note that this is the first study showing successful co-inoculation of AMF and PSB for promoting growth and yield of sunchoke in the real cultivation fields.


1995 ◽  
Vol 75 (1) ◽  
pp. 269-275 ◽  
Author(s):  
S. M. Boyetchko ◽  
J. P. Tewari

The relative susceptibility of selected barley cultivars produced in western Canada to vesicular-arbuscular mycorrhizal (VAM) fungi under field and greenhouse conditions was evaluated in this study. Cultivars tested under field conditions at the University of Alberta and Lacombe research stations showed no significant differences in VAM colonization of barley roots; colonization was light. Greenhouse trials at the University of Alberta with eight cultivars inoculated with individual mycorrhizal species illustrated significant differences among the barley cultivars in their reactions to Glomus dimorphicum, G. intraradices, and G. mosseae. Distinct differences were observed in the ability of each Glomus species to colonize the barley cultivars. The VAM fungi increased growth and yield in some cultivars, depending on the Glomus species. This study indicates that a degree of host-specificity exists in VAM fungi and that the host-mycorrhizal fungus genotypes may influence the effectiveness of the symbiosis. Key words: Barley, cultivars, susceptibility, VA mycorrhizal fungi


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Marieta Hristozkova ◽  
Liliana Gigova ◽  
Maria Geneva ◽  
Ira Stancheva ◽  
Ivanina Vasileva ◽  
...  

Abstract Mycorrhizal fungi, algae and cyanobacteria are some of the most important soil microorganisms and major components of a sustainable soil-plant system. This study presents for the first time evidence of the impact of green alga and cyanobacterium solely and in combination with arbuscular mycorrhizal fungi (AMF) on plant-antioxidant capacity. In order to provide a better understanding of the impact of AMF and soil microalgae on Ocimum basilicum L. performance, changes in the pattern and activity of the main antioxidant enzymes (AOEs), esterases and non-enzymatic antioxidants including phenols, flavonoids, ascorbate, and α-tocopherols were evaluated. The targeted inoculation of O. basilicum with AMF or algae (alone and in combination) enhanced the antioxidant capacity of the plants and the degree of stimulation varied depending on the treatment. Plants in symbiosis with AMF exhibited the highest antioxidant potential as was indicated by the enhanced functions of all studied leaf AOEs: 1.5-, 2- and more than 10-fold rises of superoxide dismutase (SOD), glutathione-S-transferase (GST) and glutathione reductase (GR), respectively. The greatest increase in the total esterase activity and concentration of phenols, flavonoids and ascorbate was marked in the plants with simultaneous inoculation of mycorrhizal fungi and the green algae. 2,2-diphenyl-1-pycril-hydrazyl (DPPH) free radical scavenging method and ferric reducing antioxidant power (FRAP) assay proved the increased plant antioxidant capacity after co-colonization of green algae and mycorrhizae.


2019 ◽  
Vol 113 (2) ◽  
pp. 321
Author(s):  
Mazen IBRAHIM

The impact of indigenous arbuscular mycorrhizal fungi (AMF) on agronomic characteristics of sunflower (<em>Helianthus annuus</em> L.) was evaluated in a pot experiment. The indigenous AMF, including <em>Glomus intraradices, Glomus mosseae</em>, and <em>Glomus viscosum</em>, were isolated from an agricultural field in which cotton and sunflower plants were grown. The most abundant species (<em>G. viscosum</em>) was multiplied in a monospecific culture. Sunflower plants were inoculated with the mixture of three selected AMF species or solely with <em>G. viscosum</em>. The number of leaves, shoot length, head diameter, above ground biomass, and seeds mass were significantly higher in the plant inoculated with AMF mixture followed by individual inoculation with <em>G. viscosum</em> followed by the control. AMF mixture outperformed the <em>G. viscosumby</em> increasing mycorrhizal dependency and mycorrhizal inoculation effect of sunflower. The results indicate that AMF mixture could be considered as a good inoculum for improving growth and yield of sunflower in sustainable agriculture.


1999 ◽  
Vol 77 (9) ◽  
pp. 1391-1397
Author(s):  
Genevieve Louise Mark ◽  
John E Hooker ◽  
Alexander Hahn ◽  
Chris T Wheeler

Micropropagated, rooted, and calli explants of Casuarina equisetifolia L. were inoculated with Frankia UGL 020605S and the arbuscular mycorrhizal fungus (AMF) Glomus mosseae, in single and dual co-culture, in vitro. Different micropropagation media formulations were evaluated for their capacity to stimulate germination of G. mosseae spores and growth of Frankia. Murashige and Skoog basal nutrient (half strength) medium, supplemented with 6-benzylaminopurine (BAP), 2,4-dichlorophenoxyacetic acid (2,4-D), and pyruvate was selected for the in vitro co-culture of C. equisetifolia callus explants, G. mosseae, and Frankia. This medium (M4) supported 70% AMF spore germination with 44 and 34% of the germinating spores producing single and branched hyphal strands, respectively. Hoaglands (quarter strength, modified by Hoaglands and Arnon (1950)) nutrient medium (M5) with no supplements was selected for the in vitro co-culture of rooted C. equisetifolia explants, G. mosseae, and Frankia and supported 57% AMF spore germination with 29 and 40% of the germinating spores producing single and branched hyphal strands, respectively. Both media supported significant growth of Frankia. In both cases agar was substituted with Terragreen(r). AMF appressoria and intercellular hyphae were observed in rooted C. equisetifolia at 28 days; arbuscule formation occurred at 56 days postinoculation. Frankia infection was evident after 28 days. This was observed in both dual and single in vitro co-cultures. No specific immunofluorescent or immunogold reactions to monoclonal antibodies (mABs) anti-Frankia < 8C5 > and anti-G. mosseae < F5G5 > were evident in C. equisetifolia callus explants.Key words: arbuscular mycorrhizal fungi (AMF), Frankia, Casuarina, micropropagation, immunofluorescent labelling.


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