Nitrogen Fertilisation Increases Specific Root Respiration in Ectomycorrhizal but Not in Arbuscular Mycorrhizal Plants: A Meta-Analysis

Plants spend a high proportion of their photosynthetically fixed carbon (C) belowground to support mycorrhizal associations in return for nutrients, but this C expenditure may decrease with increased soil nutrient availability. In this study, we assessed how the effects of nitrogen (N) fertiliser on specific root respiration (SRR) varied among mycorrhizal type (Myco type). We conducted a multi-level meta-analysis across 1,600 observations from 32 publications. SRR increased in ectomycorrhizal (ECM) plants with more than 100 kg N ha−1 applied, did not change in arbuscular mycorrhizal (AM) and non-mycorrhizal (NM) plants, but increased in plants with a dual mycorrhizal association in response to N fertilisation. Our results suggest that high N availability (>100 kg N ha−1) could disadvantage the growth of ECM plants because of increased C costs associated with maintaining higher root N concentrations, while the insensitivity in SRR by AM plants to N fertilisation may be because AM fungi are more important for phosphorus (P) uptake.

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Nutritional effects of indigenous arbuscular mycorrhizal associations on the sclerophyllous species <i>Agathosma betulina</i>

Web Ecology ◽

10.5194/we-7-77-2007 ◽

2007 ◽

Vol 7 (1) ◽

pp. 77-86 ◽

Cited By ~ 5

Author(s):

K. J. Cloete ◽

A. J. Valentine ◽

L. M. Blomerus ◽

A. Botha ◽

M. A. Pèrez-Fernández

Keyword(s):

Food Additives ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

P Uptake ◽

Ribosomal Gene ◽

Early Stages ◽

Seedling Physiology ◽

Mycorrhizal Associations ◽

Growth Respiration ◽

Arbuscular Mycorrhizal Associations

Abstract. Relatively little is currently known about the seedling physiology of arbuscular mycorrhizal (AM) Agathosma betulina, a sclerophyllous crop plant cultivated for its high-value essential oils and food additives. In addition, virtually nothing is known about the AM associations of this plant. Consequently, the effect of an indigenous community of AM fungi on P nutrition and C economy in seedlings, grown in nursery conditions, was determined during different stages of host and AM fungal establishment. AM fungal ribosomal gene sequence analyses were used to identify some of the fungi within the roots, responsible for the nutritional changes. During the early stages of host and AM fungal establishment (0 to 77 days after germination), host growth was reduced, whereas the rate of P-uptake and growth respiration was increased. Beyond 77 days of growth, the rate of P-uptake and growth respiration declined. These findings, together with results obtained after molecular analyses of root associated fungal DNA, indicate that AM fungi belonging to the genera Acaulospora and Glomus, improve P-uptake and costs of utilization during the early stages of seedling establishment in a nutrient-poor soil.

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Impacts of Urbanization Undermine Nestedness of the Plant–Arbuscular Mycorrhizal Fungal Network

Frontiers in Microbiology ◽

10.3389/fmicb.2021.626671 ◽

2021 ◽

Vol 12 ◽

Author(s):

Litao Lin ◽

Yun Chen ◽

Guorui Xu ◽

Yuxin Zhang ◽

Shuang Zhang ◽

...

Keyword(s):

Rural Areas ◽

Urban Areas ◽

Host Plants ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Illumina Miseq ◽

Forest Park ◽

Mycorrhizal Associations ◽

Mycorrhizal Association ◽

Fungal Associations

Cities are prone to ecological problems, yet the impacts of rapid global urbanization on the feedback between above- and belowground subsystems remain largely unknown. We sampled the roots of 8 common herbaceous plants within the Fifth Ring (urban areas) and in Jiufeng National Forest Park (rural areas) in Beijing (China) to assess the impacts of urbanization on the network of plant-arbuscular mycorrhizal (AM) fungal associations. Using Illumina MiSeq sequencing, 81 AM fungal OTUs were identified in 78 herb root samples. The Shannon, Simpson, and Pielou indices of root AM fungi in urban areas were significantly higher than those in rural areas. In this study, a significantly nested mycorrhizal association network was observed in rural areas (NODF = 64.68), whereas a non-nested pattern was observed in urban areas (NODF = 55.50). The competition index C-score (0.0769) of AM fungi in urban areas was slightly lower than that in rural areas (0.1431), and the species specialization (d’) of 8 host plants and fungal dissimilarity among 8 host plants in urban areas were significantly lower than those in rural areas. Convergent associations among hosts may be an important factor influencing this non-nested pattern of the plant-AM fungi network in urban areas. Generalists, rather than specialists, were enhanced during the establishment of mycorrhizal associations in urban areas. Our results suggest that reduced selectivity of host plants, and generalist promotion and specialist reduction of AM fungi during urbanization may contribute to the non-nested network of plant-AM fungal associations.

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Mycorrhizal association and influence on growth of Asian pigeonwings (Clitoria ternatea L.)

International Journal of Bioassays ◽

10.21746/ijbio.2017.06.006 ◽

2017 ◽

Vol 6 (06) ◽

pp. 5415

Author(s):

Mane S. R. ◽

Kumbhar V. R. ◽

Birajdar G. M. ◽

Naryankar R. S. ◽

Gavali M. T. ◽

...

Keyword(s):

Root Colonization ◽

Biomass Productivity ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Spore Density ◽

Clitoria Ternatea ◽

Treated Condition ◽

Mycorrhizal Association ◽

Maximum Root ◽

Herbal Medicinal

Clitoria ternatea L. is an excellent herbal medicinal plant. Arbusular Mycorrhizal fungal (AMF) colonization and biomass of three different tested conditions of Clitoria ternatea plant was investigated. Inoculums of indigenous AMF and Trichoderma harzianum was tested greenhouse experiment and compared with natural condition after 60th days of treatment. Percentage of Arbuscular mycorrhizal (AM) infection, number of resting spores and AM fungi species varies in different land. Among three different conditions, natural conditions showed maximum root colonization (75.89%) than treated one but minimum spore density (358.8/100gsoil). Highest spore density (481.6/100g soil) was found in T. harzianum treated condition followed by indigenous AMF treatment Acaulospora Glomus and Sclerocystis these three genera were found frequently. AMF inoculums and T.harzianum treatments conditions were observed promising biomass data of 60th days after treatment (DAT).When AMF are more colonized to plants then enhanced the biomass productivity.

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Influence of arbuscular mycorrhizae on soil P dynamics, corn P-nutrition and growth in a ridge-tilled commercial field

Canadian Journal of Soil Science ◽

10.4141/cjss07024 ◽

2008 ◽

Vol 88 (3) ◽

pp. 283-294 ◽

Cited By ~ 5

Author(s):

Christine P Landry ◽

Chantal Hamel ◽

Anne Vanasse

Keyword(s):

Arbuscular Mycorrhizae ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Dry Mass ◽

Soil Disturbance ◽

P Uptake ◽

P Nutrition ◽

Soil P ◽

High Yields ◽

Ridge Tillage

Ridge-tilled corn (Zea mays L.) could benefit from arbuscular mycorrhizal (AM) fungi. Under low soil disturbance, AM hyphal networks are preserved and can contribute to corn nutrition. A 2-yr study was conducted in the St. Lawrence Lowlands (Quebec, Canada) to test the effects of indigenous AM fungi on corn P nutrition, growth, and soil P in field cropped for 8 yr under ridge-tillage. Phosphorus treatments (0, 17, 35 kg P ha-1) were applied to AM-inhibited (AMI) (fungicide treated) and AM non-inhibited (AMNI) plots. Plant tissue and soil were sampled 22, 48 and 72 days after seeding (DAS). P dynamics was monitored in situ with anionic exchange membranes (PAEM) from seeding to the end of July. AMNI plants showed extensive AM colonization at all P rates. At 22 DAS, AMI plants had decreased growth in the absence of P inputs, while AMNI plants had higher dry mass (DM) and P uptake in unfertilized plots. The PAEM was lower in the AMNI unfertilized soils in 1998 and at all P rates in 1999, indicating an inverse relationship between P uptake and PAEM. At harvest, grain P content of AMNI plants was greater than that of AMI plants. In 1998, only AMI plants had decreased yield in the absence of P fertilization. In 1999, AMNI plants produced greater grain yield than AMI plants at all P rates. AM fungi improve the exploitation of soil P by corn thereby maintaining high yields while reducing crop reliance on P inputs in RT. Key words: Arbuscular mycorrhizae, ridge-tillage, soil P dynamics, corn, P nutrition

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Soil phosphorus depletion capacity of arbuscular mycorrhizae formed by maize hybrids

Canadian Journal of Soil Science ◽

10.4141/s02-037 ◽

2003 ◽

Vol 83 (4) ◽

pp. 337-342 ◽

Cited By ~ 6

Author(s):

A. Liu ◽

C. Hamel ◽

S. H. Begna ◽

B. L. Ma ◽

D. L. Smith

Keyword(s):

Plant Biomass ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

P Uptake ◽

Maize Hybrids ◽

Soil P ◽

Extractable P ◽

P Content ◽

Total P ◽

Extractable Soil

The ability of arbuscular mycorrhizal (AM) fungi to help their host plant absorb soil P is well known, but little attention has been paid to the effect of AM fungi on soil P depletion capacity. A greenhouse experiment was conducted to assess, under different P levels, the effects of mycorrhizae on extractable soil P and P uptake by maize hybrids with contrasting phenotypes. The experiment had three factors, including two mycorrhizal treatments (mycorrhizal and non-mycorrhizal), three P fertilizer rates (0, 40, and 80 mg kg-1) and three maize hybrids [leafy normal stature (LNS), leafy reduced stature (LRS) and a conventional hybrid, Pioneer 3979 (P3979)]. Extractable soil P was determined after 3, 6 and 9 wk of maize growth. Plant biomass, P concentration and total P content were also determined after 9 wk of growth. Fertilization increased soil extractable P, plant biomass, P concentration in plants and total P uptake. In contrast to P3979, the LNS and LRS hybrids had higher biomass and total P content when mycorrhizal. Mycorrhizae had less influence on soil extractable P than on total P uptake by plants. The absence of P fertilization increased the importance of AM fungi for P uptake, which markedly reduced soil extractable P under AM plants during growth. This effect was strongest for LNS, the most mycorrhizae-dependent hybrid, intermediate for LRS, and not significant for the commercial hybrid P3979, which did not respond to AM inoculation. Key words: Arbuscular mycorrhizal fungi, extraradical hyphae, maize hybrid,plant biomass, P uptake, soil extractable P

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Effect of Biochar Amendments on Mycorrhizal Associations and Fusarium Crown and Root Rot of Asparagus in Replant Soils

Plant Disease ◽

10.1094/pdis-10-10-0741 ◽

2011 ◽

Vol 95 (8) ◽

pp. 960-966 ◽

Cited By ~ 114

Author(s):

Wade H. Elmer ◽

Joseph J. Pignatello

Keyword(s):

Root Rot ◽

Root Colonization ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

First Year ◽

Root Weight ◽

Fusarium Spp ◽

Biomass Waste ◽

Mycorrhizal Associations ◽

Crown And Root Rot

Pyrolyzed biomass waste, commonly called biochar, has attracted interest as a soil amendment. A commercial prototype biochar produced by fast pyrolysis of hardwood dust was examined in soils to determine if it could reduce the damaging effect of allelopathy on arbuscular mycorrhizal (AM) root colonization and on Fusarium crown and root rot of asparagus. In greenhouse studies, biochar added at 1.5 and 3.0% (wt/wt) to asparagus field soil caused proportional increases in root weights and linear reductions in the percentage of root lesions caused by Fusarium oxysporum f. sp. asparagi and F. proliferatum compared with a control. Concomitant with these effects was a 100% increase in root colonization by AM fungi at the 3.0% rate. Addition of aromatic acids (cinnamic, coumaric, and ferulic) that are known allelopathic agents affecting asparagus reduced AM colonization but the deleterious effects were not observed following the application of biochar at the higher rate. When dried, ground, asparagus root and crown tissues infested with Fusarium spp. were added to soilless potting mix at 0, 1, or 5 g/liter of potting mix and then planted with asparagus, there was a decrease in asparagus root weight and increase in disease at 1 g/liter of potting mix but results were inconsistent at the higher residue rate. However, when biochar was added at 35 g/liter of potting mix (roughly 10%, vol/vol), these adverse effects on root weight and disease were equal to the nontreated controls. A small demonstration was conducted in field microplots. Those plots amended with biochar (3.5% [wt/wt] soil) produced asparagus plants with more AM colonization in the first year of growth but, in the subsequent year, biochar-treated plants were reduced in size, possibly due to greater than average precipitation and the ability of biochar to retain moisture that, in turn, may have created conditions conducive to root rot. These studies provide evidence that biochar may be useful in overcoming the deleterious effects of allelopathic residues in replant soils on asparagus.

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Arbuscular Mycorrhizal Community in Roots and Nitrogen Uptake Patterns of Understory Trees Beneath Ectomycorrhizal and Non-ectomycorrhizal Overstory Trees

Frontiers in Plant Science ◽

10.3389/fpls.2020.583585 ◽

2021 ◽

Vol 11 ◽

Author(s):

Chikae Tatsumi ◽

Fujio Hyodo ◽

Takeshi Taniguchi ◽

Weiyu Shi ◽

Keisuke Koba ◽

...

Keyword(s):

Community Composition ◽

Mycorrhizal Fungi ◽

N Uptake ◽

Arbuscular Mycorrhizal ◽

Nitrate Content ◽

N Availability ◽

Fungal Community Composition ◽

Mycorrhizal Association ◽

Understory Trees ◽

Overstory Trees

Nitrogen (N) is an essential plant nutrient, and plants can take up N from several sources, including via mycorrhizal fungal associations. The N uptake patterns of understory plants may vary beneath different types of overstory trees, especially through the difference in their type of mycorrhizal association (arbuscular mycorrhizal, AM; or ectomycorrhizal, ECM), because soil mycorrhizal community and N availability differ beneath AM (non-ECM) and ECM overstory trees (e.g., relatively low nitrate content beneath ECM overstory trees). To test this hypothesis, we examined six co-existing AM-symbiotic understory tree species common beneath both AM-symbiotic black locust (non-ECM) and ECM-symbiotic oak trees of dryland forests in China. We measured AM fungal community composition of roots and natural abundance stable isotopic composition of N (δ15N) in plant leaves, roots, and soils. The root mycorrhizal community composition of understory trees did not significantly differ between beneath non-ECM and ECM overstory trees, although some OTUs more frequently appeared beneath non-ECM trees. Understory trees beneath non-ECM overstory trees had similar δ15N values in leaves and soil nitrate, suggesting that they took up most of their nitrogen as nitrate. Beneath ECM overstory trees, understory trees had consistently lower leaf than root δ15N, suggesting they depended on mycorrhizal fungi for N acquisition since mycorrhizal fungi transfer isotopically light N to host plants. Additionally, leaf N concentrations in the understory trees were lower beneath ECM than the non-ECM overstory trees. Our results show that, without large differences in root mycorrhizal community, the N uptake patterns of understory trees vary between beneath different overstory trees.

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Photosynthetic performance and stevioside concentration are improved by the arbuscular mycorrhizal symbiosis in Stevia rebaudiana under different phosphate concentrations

PeerJ ◽

10.7717/peerj.10173 ◽

2020 ◽

Vol 8 ◽

pp. e10173

Author(s):

Luis G. Sarmiento-López ◽

Melina López-Meyer ◽

Gabriela Sepúlveda-Jiménez ◽

Luis Cárdenas ◽

Mario Rodríguez-Monroy

Keyword(s):

Stevia Rebaudiana ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

P Uptake ◽

Photosynthetic Performance ◽

Phosphate Concentration ◽

Mycorrhizal Symbiosis ◽

Steviol Glycosides ◽

Rebaudioside A ◽

Carotenoid Concentration

In plants, phosphorus (P) uptake occurs via arbuscular mycorrhizal (AM) symbiosis and through plant roots. The phosphate concentration is known to affect colonization by AM fungi, and the effect depends on the plant species. Stevia rebaudiana plants are valuable sources of sweetener compounds called steviol glycosides (SGs), and the principal components of SGs are stevioside and rebaudioside A. However, a detailed analysis describing the effect of the phosphate concentration on the colonization of AM fungi in the roots and the relationship of these factors to the accumulation of SGs and photochemical performance has not been performed; such an analysis was the aim of this study. The results indicated that low phosphate concentrations (20 and 200 µM KH2PO4) induced a high percentage of colonization by Rhizophagus irregularis in the roots of S. rebaudiana, while high phosphate concentrations (500 and 1,000 µM KH2PO4) reduced colonization. The morphology of the colonization structure is a typical Arum-type mycorrhiza, and a mycorrhiza-specific phosphate transporter was identified. Colonization with low phosphate concentrations improved plant growth, chlorophyll and carotenoid concentration, and photochemical performance. The transcription of the genes that encode kaurene oxidase and glucosyltransferase (UGT74G1) was upregulated in colonized plants at 200 µM KH2PO4, which was consistent with the observed patterns of stevioside accumulation. In contrast, at 200 µM KH2PO4, the transcription of UGT76G1 and the accumulation of rebaudioside A were higher in noncolonized plants than in colonized plants. These results indicate that a low phosphate concentration improves mycorrhizal colonization and modulates the stevioside and rebaudioside A concentration by regulating the transcription of the genes that encode kaurene oxidase and glucosyltransferases, which are involved in stevioside and rebaudioside A synthesis in S. rebaudiana.

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Biogeochemical Effects of a Forest Understory Plant Invasion Depend More On Dissimilar Nutrient Economies Than Invader Biomass

10.21203/rs.3.rs-941156/v1 ◽

2021 ◽

Author(s):

Laura Y Podzikowski ◽

Marissa Lee ◽

Catherine Fahey ◽

Justin Wright ◽

S. Luke Flory ◽

...

Keyword(s):

Native Species ◽

Soil Nutrient ◽

Arbuscular Mycorrhizal ◽

Nutrient Acquisition ◽

Forest Understory ◽

Soil Conditions ◽

N Availability ◽

Invasive Grass ◽

Acquisition Strategies ◽

Nutrient Economy

Abstract There is an increasing need to better understand how and why invasion impacts differ across heterogeneous landscapes. One hypothesis predicts invader impacts are greatest where the invader is most abundant (the mass ratio hypothesis; MRH). Alternatively, invader impacts may be greatest in communities where the nutrient acquisition strategies of the invader are most dissimilar from those of native species (the nutrient economy dissimilarity hypothesis; NEDH). We tested whether the effects of an invasive grass, Microstegium vimineum, on soil biogeochemistry were best explained by MRH, NEDH, or both. At three locations (Indiana, North Carolina, and Georgia), invaded and reference plots were established across a nutrient economy gradient. Plots varied in the relative abundance of arbuscular mycorrhizal (AM) vs. ectomycorrhizal (ECM) associated overstory trees, reflecting gradients in biotic nutrient acquisition strategies and edaphic factors. At two locations, we found NEDH predicted invader effects on soil conditions. The net effect of M. vimineum homogenized soil properties across the nutrient economy gradient towards conditions consistent with AM-dominated stands; as such, the nutrient economy gradients observed in uninvaded plots were mostly absent in invaded plots. At one location with high N availability and intermediate acidity, both ECM-dominance (NEDH) and invader abundance (MRH) predicted differences in soil moisture, pH, and nitrification rates. Collectively, these results suggest the biogeochemical consequences of M. vimineum depend, in part, on pre-invasion soil nutrient economies. Where pre-invasion conditions are known, we provide a scalable and predictive approach to determine where impacts on biogeochemical cycling of C and N may be greatest.

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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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