Long-term effect of heavy metal loads on the mycorrhizal colonization and metal uptake of barley

A pot experiment was designed to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) on barley ( Hordeum vulgare L.) host plant. Soils of the pots were collected from a long-term field microelement loading experiment on calcareous chernozem soil twelve years after 13 heavy metals (Al, As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sr and Zn) were applied once in four doses (0, 30, 90 and 270 mg element·kg -1 d.w.). The biomass production and element accumulation of the host plant, the various colonization values of the arbuscular mycorrhiza fungi (AMF) – such as colonization intensity (M %), arbusculum richness (A %) in the root system and the sporulation intensity (g -1 dry soil) in the rhizosphere – were measured. When considering the twelve-year adaptation process of the AM fungal populations at the various metal loads, a relatively balanced inside mycorrhiza colonization was found, suggesting the potentials for the selection of tolerant fungi in metal contaminated soils. The balanced infection intensity (M %) of the AM fungi and their common strategies with the host plant have resulted a nonsignificant shoot and root biomass production of barley in general. Mycorrhiza sporulation in the root system proved to be much variable and indicated the toxicity of metals and metal rates. Cd, Pb and Sr elements significantly reduced spore numbers, while a value of 34 spores·g -1 soil was counted in the case of Ni in comparison to the control’s 22 spores·g -1 soil value. Stress-defending strategies of the fungal–plant symbiosis, such as the increased arbusculum richness (A %) could be established for the Hg and Pb rates. In the case of Cd an increased root biomass production became a tool for stress alleviation and reduced the metal allocation towards the shoots. Mycorrhiza fungi are part of the common plant–microbe interactions and appropriate defending mechanisms in metal contaminated soils.

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Mycorrhizal inoculation and application of Fe correction in the soil for ameliorating grapevine performance in a copper-contaminated soil

10.5194/egusphere-egu21-4254 ◽

2021 ◽

Author(s):

Amaia Nogales ◽

Erika S. Santos ◽

Gonçalo Victorino ◽

Wanda Viegas ◽

Maria Manuela Abreu

Keyword(s):

Soil Contamination ◽

Contaminated Soil ◽

Contaminated Soils ◽

Mycorrhizal Fungi ◽

Root Biomass ◽

Arbuscular Mycorrhizal ◽

Nutrient Contents ◽

Beneficial Effects ◽

Continuous Application ◽

Mycorrhizal Inoculation

<p>Copper-based fungicides are commonly applied in vineyards to control fungal diseases that can severely affect grapevine productivity. Continuous application of this type of fungicides contributes to Cu accumulation in surface horizons of the soil, which can generate toxicity problems in plants, regardless of being an essential nutrient. Several strategies have been proposed to immobilize or counteract the effect of soil contaminants, such as plant inoculation with arbuscular mycorrhizal fungi (AMF). However, depending on the element concentration, this may not be sufficient to avoid its excessive accumulation in belowground and/or aboveground organs. Since Fe is known to have an antagonistic interaction with Cu in plants, Fe application, as an amendment, in vineyard soils, could be a good strategy to avoid excessive Cu uptake by grapevines growing in Cu-contaminated soils. However, little information is available on the combined effects of both strategies.</p><p>In order to reveal the possible beneficial effects of plant mycorrhization and Fe application in Cu-contaminated soils on grapevine growth and nutrition, a mesocosm experiment was established under controlled conditions. Two-year-old plants, previously inoculated or not with two different AMF, were grown in pots filled with 6.5 kg of an Arenosol collected from a wine-growing region. These plants were subjected to three soil treatments: 1) soil contamination with Cu, where the grapevines were watered with a solution containing 5.89 mg/L CuSO<sub>4</sub> to ensure that the soil in each container reached 300 mg Cu/kg; 2) soil contamination with Cu + Fe addition, where the plants were watered with a solution that contained the same amount of CuSO<sub>4</sub> plus 0.38 mg/L of FeNaEDTA&#183;3H<sub>2</sub>O to achieve 100 mg of Fe/kg soil; and 3) non-contaminated soil watered with deionized water. Four months later, at the end of the growing season, plant vegetative growth as well as leaf and root nutrient contents were analyzed.</p><p>Grapevines inoculated with AMF demonstrated a good level of tolerance to high Cu concentrations in soil, as they presented significantly higher root biomass than non-inoculated plants and Cu was mainly accumulated in the roots avoiding its translocation to the aerial part. However, when the Cu-contaminated soil was amended with Fe, a significant decrease was observed in root biomass in all mycorrhizal inoculation treatments and Cu was accumulated in grapevine leaves. Contrastingly, Fe application helped to avoid the excessive increase of Mn concentrations in leaf and roots that is commonly induced in Cu contaminated soils, which can be detrimental for grapevine growth.</p><p>These results demonstrated that mycorrhizal inoculation is a suitable strategy to promote grapevine growth in Cu-contaminated soils. However, special attention needs to be taken when applying amendments to correct Cu contamination, as the mycorrhizal status of plants may alter the expected outcome.</p><p>&#160;</p><div> <div>&#160;</div> </div>

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Response of Arbuscular Mycorrhizal Fungi to Hydrologic Gradients in the Rhizosphere ofPhragmites australis(Cav.) Trin ex. Steudel Growing in the Sun Island Wetland

BioMed Research International ◽

10.1155/2015/810124 ◽

2015 ◽

Vol 2015 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Li Wang ◽

Jieting Wu ◽

Fang Ma ◽

Jixian Yang ◽

Shiyang Li ◽

...

Keyword(s):

Host Plant ◽

Mycorrhizal Fungi ◽

Plant Biomass ◽

Growth Parameters ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

The Sun ◽

Vegetative Period ◽

Hydrologic Gradients ◽

Mycorrhizal Association

Within the rhizosphere, AM fungi are a sensitive variable to changes of botanic and environmental conditions, and they may interact with the biomass of plant and other microbes. During the vegetative period of thePhragmites australisgrowing in the Sun Island Wetland (SIW), the variations of AM fungi colonization were studied. Root samples of three hydrologic gradients generally showed AM fungi colonization, suggesting that AM fungi have the ability for adaptation to flooded habitats. There were direct and indirect hydrological related effects with respect to AM fungi biomass, which interacted simultaneously in the rhizosphere. Though water content in soil and reed growth parameters were both positively associated with AM fungi colonization, only the positive correlations between reed biomass parameters and the colonization could be expected, or both the host plant biomass and the AM fungi could be beneficial. The variations in response of host plant to the edaphic and hydrologic conditions may influence the effectiveness of the plant-mycorrhizal association. This study included a hydrologic component to better assess the role and distribution of AM fungi in wetland ecosystems. And because of that, the range of AM fungi was extended, since they actually showed a notable adaptability to hydrologic gradients.

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Infection intensity, spore density and inoculum potential of arbuscular mycorrhizal fungi decrease during secondary succession in tropical Brazilian ecosystems

Journal of Tropical Ecology ◽

10.1017/s0266467412000399 ◽

2012 ◽

Vol 28 (5) ◽

pp. 453-462 ◽

Cited By ~ 14

Author(s):

Waldemar Zangaro ◽

Adrielly Pereira Ansanelo ◽

Luis Eduardo Azevedo Marques Lescano ◽

Ricardo de Almeida Alves ◽

Artur Berbel Lírio Rondina ◽

...

Keyword(s):

Mycorrhizal Fungi ◽

Secondary Forest ◽

Infection Intensity ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Spore Density ◽

Inoculum Potential ◽

Secondary Forests ◽

Early Stages ◽

Successional Stages

Abstract:Little is known about the relationship involving arbuscular mycorrhizal (AM) fungi and functional groups of plants that characterize different phases of tropical succession. We appraised the AM infection intensity of root cortex and spore density in the soil in sites over tropical successional gradients (grassland, secondary forest and mature forest) for several years in Araucaria, Atlantic and Pantanal ecosystems in Brazil. The intensity of AM infection decreased with advancing successional stages in all ecosystems and it was around 60–80% in early stages of succession, 37–56% in secondary forests and 19–29% in mature forests. Similarly, the AM spore number also decreased with advancing succession and was the highest in early stages (73–123 g−1), intermediate in secondary forests (32–54 g−1) and lowest in the mature forests (10–23 g−1). To verify whether such reductions influenced the potential of AM inoculum in soil, seedlings of Heliocarpus popayanensis (Malvaceae) were grown as test plants in soils obtained from five grasslands, five young secondary forests, and five mature forests in the Atlantic ecosystem. The soil inocula from the grasslands and secondary forests were 7.6 and 5.7 times more effective in stimulating seedling growth than inocula from the mature forests, respectively. Our results show that plant species in grasslands and young secondary forests stimulate the multiplication of AM fungi, leading to a higher potential of the AM inoculum. In later-successional stages, plant investment in AM fungi decreases and the potential of the AM inoculum is also reduced.

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Hormonomic Changes Driving the Negative Impact of Broomrape on Plant Host Interactions with Arbuscular Mycorrhizal Fungi

International Journal of Molecular Sciences ◽

10.3390/ijms222413677 ◽

2021 ◽

Vol 22 (24) ◽

pp. 13677

Author(s):

Kiril Mishev ◽

Petre I. Dobrev ◽

Jozef Lacek ◽

Roberta Filepová ◽

Bistra Yuperlieva-Mateeva ◽

...

Keyword(s):

Host Plant ◽

Mycorrhizal Fungi ◽

Negative Impact ◽

Dominant Role ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Parasitic Plants ◽

Plant Roots ◽

Plant Host ◽

Mycorrhizal Roots

Belowground interactions of plants with other organisms in the rhizosphere rely on extensive small-molecule communication. Chemical signals released from host plant roots ensure the development of beneficial arbuscular mycorrhizal (AM) fungi which in turn modulate host plant growth and stress tolerance. However, parasitic plants have adopted the capacity to sense the same signaling molecules and to trigger their own seed germination in the immediate vicinity of host roots. The contribution of AM fungi and parasitic plants to the regulation of phytohormone levels in host plant roots and root exudates remains largely obscure. Here, we studied the hormonome in the model system comprising tobacco as a host plant, Phelipanche spp. as a holoparasitic plant, and the AM fungus Rhizophagus irregularis. Co-cultivation of tobacco with broomrape and AM fungi alone or in combination led to characteristic changes in the levels of endogenous and exuded abscisic acid, indole-3-acetic acid, cytokinins, salicylic acid, and orobanchol-type strigolactones. The hormonal content in exudates of broomrape-infested mycorrhizal roots resembled that in exudates of infested non-mycorrhizal roots and differed from that observed in exudates of non-infested mycorrhizal roots. Moreover, we observed a significant reduction in AM colonization of infested tobacco plants, pointing to a dominant role of the holoparasite within the tripartite system.

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Growth responses of sugarcane to mycorrhizal spore density and phosphorus rate

Australian Journal of Agricultural Research ◽

10.1071/ar04185 ◽

2005 ◽

Vol 56 (12) ◽

pp. 1405 ◽

Cited By ~ 7

Author(s):

R. M. Kelly ◽

D. G. Edwards ◽

J. P. Thompson ◽

R. C. Magarey

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Spore Density ◽

Yield Response ◽

Yield Reduction ◽

Growth Responses ◽

Root Colonisation ◽

P Concentration

Arbuscular mycorrhizal (AM) fungi, commonly found in long-term cane-growing fields in northern Queensland, are linked with both negative and positive growth responses by sugarcane (Saccharum spp.), depending on P supply. A glasshouse trial was established to examine whether AM density might also have an important influence on these growth responses. Mycorrhizal spores (Glomus clarum), isolated from a long-term cane block in northern Queensland, were introduced into a pasteurised low-P cane soil at 5 densities (0, 0.06, 0.25, 1, 4 spores/g soil) and with 4 P treatments (0, 8.2, 25, and 47 mg/kg). At 83 days after planting, sugarcane tops responded positively to P fertilizer, although responses attributable to spore density were rarely observed. In one case, addition of 4 spores/g led to a 53% yield response over those without AM at 8 mg P/kg, or a relative benefit of 17 mg P/kg. Root colonisation was reduced for plants with nil or 74 mg P/kg. For those without AM, P concentration in the topmost visible dewlap (TVD) leaf increased significantly with fertiliser P (0.07 v. 0.15%). However, P concentration increased further with the presence of AM spores. Irrespective of AM, the critical P concentration in the TVD leaf was 0.18%. This study confirms earlier reports that sugarcane is poorly responsive to AM. Spore density, up to 4 spores/g soil, appears unable to influence this responsiveness, either positively or negatively. Attempts to gain P benefits by increasing AM density through rotation seem unlikely to lead to yield increases by sugarcane. Conversely, sugarcane grown in fields with high spore densities and high plant-available P, such as long-term cane-growing soils, is unlikely to suffer a yield reduction from mycorrhizal fungi.

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Plantago lanceolata growth and Cr uptake after mycorrhizal inoculation in a Cr amended substrate

Agricultural and Food Science ◽

10.23986/afsci.5007 ◽

2012 ◽

Vol 21 (1) ◽

pp. 72-79 ◽

Cited By ~ 1

Author(s):

Amaia Nogales ◽

Amparo Cortés ◽

Konstantinos Velianos ◽

Amelia Camprubí ◽

Victoria Estaún ◽

...

Keyword(s):

Contaminated Soils ◽

Mycorrhizal Fungi ◽

Glomus Intraradices ◽

Plantago Lanceolata ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Contaminated Sites ◽

Mycorrhizal Inoculation ◽

Cr Uptake ◽

Cr Contamination

Arbuscular mycorrhizal fungi from two chromium contaminated sites, one with 275 mg kg-1 of Cr (zone A) and the other with 550 mg kg-1 Cr (zone B), were multiplied and tentatively identified. The effect of both fungal consortia on Plantago lanceolata plant growth in a substrate amended with 200 mg kg-1 of Cr and with 400 mg kg-1 Cr was assessed and compared with the growth of plants inoculated with Glomus intraradices BEG72. Only the plants inoculated with G. intraradices BEG72 and with the fungal consortia obtained from the area with a high Cr contamination (zone B) grew in the soil with 400 mg kg-1 of Cr. The consortia of fungi from zone B, decreased the plant’s uptake/translocation of the heavy metal compared with G. intraradices BEG72. These results underscore the differential effect of AM fungi in conferring bioprotection in Cr contaminated soils.

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Effects of Metal Phytoextraction Practices on the Indigenous Community of Arbuscular Mycorrhizal Fungi at a Metal-Contaminated Landfill

Applied and Environmental Microbiology ◽

10.1128/aem.66.6.2526-2530.2000 ◽

2000 ◽

Vol 66 (6) ◽

pp. 2526-2530 ◽

Cited By ~ 69

Author(s):

Teresa E. Pawlowska ◽

Rufus L. Chaney ◽

Mel Chin ◽

Iris Charvat

Keyword(s):

Plant Species ◽

Mycorrhizal Fungi ◽

Root Colonization ◽

Soil Amendments ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Spore Density ◽

Silene Vulgaris ◽

Negative Effect

ABSTRACT Phytoextraction involves use of plants to remove toxic metals from soil. We examined the effects of phytoextraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays) and a factorial variation of soil amendments (either an ammonium or nitrate source of nitrogen and the presence or absence of an elemental sulfur supplement) on arbuscular mycorrhizal (AM) fungi (Glomales, Zygomycetes) at a moderately metal-contaminated landfill located in St. Paul, Minn. Specifically, we tested whether the applied treatments affected the density of glomalean spores and AM root colonization in maize. Glomalean fungi from the landfill were grouped into two morphotypes characterized by either light-colored spores (LCS) or dark-colored spores (DCS). Dominant species of the LCS morphotype were Glomus mosseae and an unidentified Glomus sp., whereas the DCS morphotype was dominated by Glomus constrictum. The density of spores of the LCS morphotype from the phytoremediated area was lower than the density of these spores in the untreated landfill soil. Within the experimental area, spore density of the LCS morphotype in the rhizosphere of mycorrhizal maize was significantly higher than in rhizospheres of nonmycorrhizal S. vulgaris or T. caerulescens. Sulfur supplement increased vesicular root colonization in maize and exerted a negative effect on spore density in maize rhizosphere. We conclude that phytoextraction practices, e.g., the choice of plant species and soil amendments, may have a great impact on the quantity and species composition of glomalean propagules as well as on mycorrhiza functioning during long-term metal-remediation treatments.

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Faculty Opinions recommendation of Fatty acids in arbuscular mycorrhizal fungi are synthesized by the host plant.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727697782.793545176 ◽

2018 ◽

Author(s):

Ivo Feussner ◽

Till Ischebeck

Keyword(s):

Fatty Acids ◽

Arbuscular Mycorrhizal Fungi ◽

Host Plant ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal

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Use of the Signature Fatty Acid 16:1ω5 as a Tool to Determine the Distribution of Arbuscular Mycorrhizal Fungi in Soil

Journal of Lipids ◽

10.1155/2012/236807 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 43

Author(s):

Christopher Ngosong ◽

Elke Gabriel ◽

Liliane Ruess

Keyword(s):

Fatty Acid ◽

Mycorrhizal Fungi ◽

Plant Root ◽

Background Level ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Biomass Estimation ◽

Lipid Fatty Acid ◽

Neutral Lipid Fatty Acid ◽

Root Symbionts

Biomass estimation of arbuscular mycorrhiza (AM) fungi, widespread plant root symbionts, commonly employs lipid biomarkers, predominantly the fatty acid 16:1ω5. We briefly reviewed the application of this signature fatty acid, followed by a case study comparing biochemical markers with microscopic techniques in an arable soil following a change to AM non-host plants after 27 years of continuous host crops, that is, two successive cropping seasons with wheat followed by amaranth. After switching to the non-host amaranth, spore biomass estimated by the neutral lipid fatty acid (NLFA) 16:1ω5 decreased to almost nil, whereas microscopic spore counts decreased by about 50% only. In contrast, AM hyphal biomass assessed by the phospholipid (PLFA) 16:1ω5 was greater under amaranth than wheat. The application of PLFA 16:1ω5 as biomarker was hampered by background level derived from bacteria, and further enhanced by its incorporation from degrading spores used as microbial resource. Meanwhile, biochemical and morphological assessments showed negative correlation for spores and none for hyphal biomass. In conclusion, the NLFA 16:1ω5 appears to be a feasible indicator for AM fungi of the Glomales group in the complex field soils, whereas the use of PLFA 16:1ω5 for hyphae is unsuitable and should be restricted to controlled laboratory studies.

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