scholarly journals Carbon investment into mobilization of mineral and organic phosphorus by arbuscular mycorrhiza

2020 ◽  
Vol 57 (1) ◽  
pp. 47-64
Author(s):  
Alberto Andrino ◽  
Georg Guggenberger ◽  
Leopold Sauheitl ◽  
Stefan Burkart ◽  
Jens Boy
Keyword(s):  
Fatty Acid ◽  
Arbuscular Mycorrhiza ◽  
Mycorrhizal Fungi ◽  
Organic Phosphorus ◽  
Phospholipid Fatty Acid ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
P Availability ◽  
Organic C ◽  
P Deficiency

AbstractTo overcome phosphorus (P) deficiency, about 80% of plant species establish symbiosis with arbuscular mycorrhizal fungi (AMF), which in return constitute a major sink of photosynthates. Information on whether plant carbon (C) allocation towards AMF increases with declining availability of the P source is limited. We offered orthophosphate (OP), apatite (AP), or phytic acid (PA) as the only P source available to arbuscular mycorrhiza (AM) (Solanum lycopersicum x Rhizophagus irregularis) in a mesocosm experiment, where the fungi had exclusive access to each P source. After exposure, we determined P contents in the plant, related these to the overall C budget of the system, including the organic C (OC) contents, the respired CO2, the phospholipid fatty acid (PLFA) 16:1ω5c (extraradical mycelium), and the neutral fatty acid (NLFA) 16:1ω5c (energy storage) at the fungal compartment. Arbuscular mycorrhizal (AM) plants incorporated P derived from the three P sources through the mycorrhizal pathway, but did this with differing C-P trading costs. The mobilization of PA and AP by the AM plant entailed larger mycelium infrastructure and significantly larger respiratory losses of CO2, in comparison with the utilization of the readily soluble OP. Our study thus suggests that AM plants invest larger C amounts into their fungal partners at lower P availability. This larger C flux to the AM fungi might also lead to larger soil organic C contents, in the course of forming larger AM biomass under P-limiting conditions.

scholarly journals Fungal Lipid Accumulation and Development of Mycelial Structures by Two Arbuscular Mycorrhizal Fungi

2003 ◽  
Vol 69 (11) ◽  
pp. 6762-6767 ◽  
Author(s):  
Ingrid M. van Aarle ◽  
Pål Axel Olsson
Keyword(s):  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Glomus Intraradices ◽  
Neutral Lipids ◽  
Phospholipid Fatty Acid ◽  
Plantago Lanceolata ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fungal Species ◽  
Opposite Pattern

ABSTRACT We monitored the development of intraradical and extraradical mycelia of the arbuscular mycorrhizal (AM) fungi Scutellospora calospora and Glomus intraradices when colonizing Plantago lanceolata. The occurrence of arbuscules (branched hyphal structures) and vesicles (lipid storage organs) was compared with the amounts of signature fatty acids. The fatty acid 16:1ω5 was used as a signature for both AM fungal phospholipids (membrane constituents) and neutral lipids (energy storage) in roots (intraradical mycelium) and in soil (extraradical mycelium). The formation of arbuscules and the accumulation of AM fungal phospholipids in intraradical mycelium followed each other closely in both fungal species. In contrast, the neutral lipids of G. intraradices increased continuously in the intraradical mycelium, while vesicle occurrence decreased after initial rapid root colonization by the fungus. S. calospora does not form vesicles and accumulated more neutral lipids in extraradical than in intraradical mycelium, while the opposite pattern was found for G. intraradices. G. intraradices allocated more of its lipids to storage than did S. calospora. Thus, within a species, the fatty acid 16:1ω5 is a good indicator for AM fungal development. The phospholipid fatty acid 16:1ω5 is especially suitable for indicating the frequency of arbuscules in the symbiosis. We propose that the ratio of neutral lipids to phospholipids is more important than is the presence of vesicles in determining the storage status of AM fungi.

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

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
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.

scholarly journals Contribution of Arbuscular Mycorrhizal Fungi, Phosphate–Solubilizing Bacteria, and Silicon to P Uptake by Plant

2021 ◽  
Vol 12 ◽  
Author(s):  
Hassan Etesami ◽  
Byoung Ryong Jeong ◽  
Bernard R. Glick
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Crop Production ◽  
Current Knowledge ◽  
Arbuscular Mycorrhizal ◽  
P Availability ◽  
Phosphate Solubilizing Bacteria ◽  
P Deficiency ◽  
Phosphate Solubilizing ◽  
P Fertilizers

Phosphorus (P) availability is usually low in soils around the globe. Most soils have a deficiency of available P; if they are not fertilized, they will not be able to satisfy the P requirement of plants. P fertilization is generally recommended to manage soil P deficiency; however, the low efficacy of P fertilizers in acidic and in calcareous soils restricts P availability. Moreover, the overuse of P fertilizers is a cause of significant environmental concerns. However, the use of arbuscular mycorrhizal fungi (AMF), phosphate–solubilizing bacteria (PSB), and the addition of silicon (Si) are effective and economical ways to improve the availability and efficacy of P. In this review the contributions of Si, PSB, and AMF in improving the P availability is discussed. Based on what is known about them, the combined strategy of using Si along with AMF and PSB may be highly useful in improving the P availability and as a result, its uptake by plants compared to using either of them alone. A better understanding how the two microorganism groups and Si interact is crucial to preserving soil fertility and improving the economic and environmental sustainability of crop production in P deficient soils. This review summarizes and discusses the current knowledge concerning the interactions among AMF, PSB, and Si in enhancing P availability and its uptake by plants in sustainable agriculture.

scholarly journals Myristate can be used as a carbon and energy source for the asymbiotic growth of arbuscular mycorrhizal fungi

2019 ◽  
Author(s):  
Yuta Sugiura ◽  
Rei Akiyama ◽  
Sachiko Tanaka ◽  
Koji Yano ◽  
Hiromu Kameoka ◽  
...  
Keyword(s):  
Energy Source ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Unsaturated Fatty Acids ◽  
Fungal Growth ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Land Plants ◽  
Symbiotic Associations

AbstractArbuscular mycorrhizal (AM) fungi, forming symbiotic associations with land plants, are obligate symbionts that cannot complete their natural life cycle without a host. Recently, fatty acid auxotrophy of AM fungi is supported by studies showing that lipids synthesized by the host plants are transferred to the fungi and that the latter lack genes encoding cytosolic fatty acid synthases (1-7). Therefore, to establish an asymbiotic cultivation system for AM fungi, we tried to identify the fatty acids that could promote biomass production. To determine whether AM fungi can grow on medium supplied with fatty acids or lipids under asymbiotic conditions, we tested eight saturated or unsaturated fatty acids (C12–C18) and two β-monoacylglycerols. Only myristate (C14:0) led to an increase in biomass of Rhizophagus irregularis, inducing extensive hyphal growth and formation of infection-competent secondary spores. However, such spores were smaller than those generated symbiotically. Furthermore, we demonstrated that R. irregularis can take up fatty acids in its branched hyphae and use myristate as a carbon and energy source. Myristate also promoted the growth of Rhizophagus clarus and Gigaspora margarita. Finally, mixtures of myristate and palmitate accelerated fungal growth and induced a substantial change in fatty acid composition of triacylglycerol compared with single myristate application, although palmitate was not used as a carbon source for cell wall biosynthesis in this culture system. In conclusion, here we demonstrate that myristate boosts asymbiotic growth of AM fungi and can also serve as a carbon and energy source.Significance statementThe origins of arbuscular mycorrhizal (AM) fungi, which form symbiotic associations with land plants, date back over 460 million years ago. During evolution, these fungi acquired an obligate symbiotic lifestyle, and thus depend on their host for essential nutrients. In particular, fatty acids are regarded as crucial nutrients for the survival of AM fungi owing to the absence of genes involved in de novo fatty acid biosynthesis in the AM fungal genomes that have been sequenced so far. Here, we show that myristate initiates AM fungal growth under asymbiotic conditions. These findings will advance pure culture of AM fungi.

Effect of arbuscular mycorrhizal fungi and phosphorus fertilization on the post vitro growth and yield of micropropagated strawberry grown in a sandy loam soil

2004 ◽  
Vol 82 (3) ◽  
pp. 322-328 ◽  
Author(s):  
Mahaveer P Sharma ◽  
Alok Adholeya
Keyword(s):  
Mycorrhizal Fungi ◽  
Sandy Loam ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Fruit Yield ◽  
Growth And Yield ◽  
Phosphorus Fertilization ◽  
P Availability ◽  
P Fertilization ◽  
Mycorrhizal Dependency

Strawberries (Fragaria ×ananassa Duch.) grown in alfisols of semiarid areas in India results in suboptimal yields. Low organic carbon and low phosphorus (P) availability, in addition to high P fixation, affects P availability drastically, even when it is applied externally. The benefit to the yield of micropropagated strawberry Fragaria ×ana nassa 'Pajaro' through inoculation with arbuscular mycorrhizal (AM) fungi and P application was examined in a field experiment. AM response was evaluated at four doses of P (50, 100, 150, and 200 kg P·ha–1) in a high P-fixing capacity and P-deficient alfisol. At harvest, all inoculated plants, except those at the highest level of applied P (200 kg·ha–1), had larger fruit yields per plant, unit mass, number of runners, higher shoot dry matter, and shoot P content. However, the AM response as measured by yield varied with P concentration. Inoculated plants had a significantly greater fruit yield when grown at 150 kg P·ha–1, and the yield was comparable with uninoculated plants grown at 200 kg P·ha–1. The external P requirements were 71 kg·ha–1 for mycorrhizal and 106 kg·ha–1 for nonmycorrhizal strawberry plants to obtain 90% of the maximum fruit yield. In terms of P fertilization, this corresponds to a savings of 35 kg·ha–1. The percent mycorrhizal root length colonization, both in inoculated and noninoculated plants, was not found to differ significantly with P application.Key words: strawberry, P fertilization, mycorrhizal dependency.

scholarly journals Myristate can be used as a carbon and energy source for the asymbiotic growth of arbuscular mycorrhizal fungi

2020 ◽  
Vol 117 (41) ◽  
pp. 25779-25788
Author(s):  
Yuta Sugiura ◽  
Rei Akiyama ◽  
Sachiko Tanaka ◽  
Koji Yano ◽  
Hiromu Kameoka ◽  
...  
Keyword(s):  
Energy Source ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Mycorrhizal Fungi ◽  
Unsaturated Fatty Acids ◽  
Fungal Growth ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Hyphal Growth ◽  
Symbiotic Associations

Arbuscular mycorrhizal (AM) fungi, forming symbiotic associations with land plants, are obligate symbionts that cannot complete their natural life cycle without a host. The fatty acid auxotrophy of AM fungi is supported by recent studies showing that lipids synthesized by the host plants are transferred to the fungi, and that the latter lack genes encoding cytosolic fatty acid synthases. Therefore, to establish an asymbiotic cultivation system for AM fungi, we tried to identify the fatty acids that could promote biomass production. To determine whether AM fungi can grow on medium supplied with fatty acids or lipids under asymbiotic conditions, we tested eight saturated or unsaturated fatty acids (C12 to C18) and two β-monoacylglycerols. Only myristate (C14:0) led to an increase in the biomass ofRhizophagus irregularis, inducing extensive hyphal growth and formation of infection-competent secondary spores. However, such spores were smaller than those generated symbiotically. Furthermore, we demonstrated thatR. irregulariscan take up fatty acids in its branched hyphae and use myristate as a carbon and energy source. Myristate also promoted the growth ofRhizophagus clarusandGigaspora margarita. Finally, mixtures of myristate and palmitate accelerated fungal growth and induced a substantial change in fatty acid composition of triacylglycerol compared with single myristate application, although palmitate was not used as a carbon source for cell wall biosynthesis in this culture system. Our findings demonstrate that myristate boosts the asymbiotic growth of AM fungi and can also serve as a carbon and energy source.

scholarly journals Effects of arbuscular mycorrhizal fungi on rice-herbivore interactions are soil-dependent

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lina Bernaola ◽  
Michael J. Stout
Keyword(s):  
Mycorrhizal Fungi ◽  
Plant Biomass ◽  
Fall Armyworm ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Nutrient Concentrations ◽  
P Availability ◽  
Soil P ◽  
Rice Plants ◽  
Rice Water

Abstract The effect of soil type on establishment of arbuscular mycorrhizal (AM) fungi, and their effects on plant growth and resistance to rice pests are poorly understood. We investigated the effects of inoculation with AM fungi on rice plants in two different unsterilized field soils under greenhouse and field conditions in two consecutive years in Louisiana, United States. We tested whether inoculation with AM fungi in the two soils changed plant biomass, nutrient concentration, resistance to pests, and yields. Inoculation with a commercial formulation of AM fungi increased root colonization by fungi in all soils, regardless of soil P availability; it also increased densities of root-feeding rice water weevil larvae and growth of leaf-feeding fall armyworm larvae, but these effects were soil-dependent. Inoculation with AM fungi had no effect on N and P concentrations or rice yields. The effect on plant biomass was also soil-dependent. Our study provides evidence for the first time that inoculation with AM fungi can increase colonization of roots of rice plants, but the effects of colonization on resistance to pests and plant biomass appear to be soil dependent. Moreover, the increased susceptibility to pests of rice colonized by AM fungi does not appear to be related to nutrient concentrations.

scholarly journals Response of Arbuscular Mycorrhizal Fungi to Simulated Climate Changes by Reciprocal Translocation in Tibetan Plateau

2015 ◽  
Vol 43 (2) ◽  
pp. 488-493
Author(s):  
Zhaoyong SHI ◽  
Xubin YIN ◽  
Bede MICKAN ◽  
Fayuan WANG ◽  
Ying ZHANG ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Arbuscular Mycorrhizal Fungi ◽  
Reciprocal Translocation ◽  
Mycorrhizal Fungi ◽  
Climate Changes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Spore Density ◽  
The Tibetan Plateau ◽  
Colonization Frequency

Arbuscular mycorrhiza (AM) fungi are considered as an important factor in predicting plants and ecosystem responses to climate changes on a global scale. The Tibetan Plateau is the highest region on Earth with abundant natural resources and one of the most sensitive region to climate changes. To evaluate the complex response of arbuscular mycorrhizal fungi colonization and spore density to climate changes, a reciprocal translocation experiment was employed in Tibetan Plateau. The reciprocal translocation of quadrats to AM colonization and spore density were dynamic. Mycorrhizal colonization frequency presented contrary changed trend with elevations of quadrat translocation. Colonization frequency reduced or increased in majority quadrats translocated from low to high or from high to low elevation. Responses of colonization intensity to translocation of quadrats were more sensitive than colonization frequency. Arbuscular colonization showed inconsistent trend in increased or decreased quadrat. Vesicle colonization decreased with changed of quadrat from low to high elevations. However, no significant trend was observed. Although spore density was dynamic with signs of decreasing or increasing in translocated quadrats, the majority enhanced and declined respectively in descent and ascent quadrat treatments. It is crucial to understand the interactions between AM fungi and prairie grasses to accurately predict effects of climate change on these diverse and sensitive ecosystems. This study provided an opportunity for understanding the effect of climate changes on AM fungi.

scholarly journals The Phosphate Inhibition Paradigm: Host and Fungal Genotypes Determine Arbuscular Mycorrhizal Fungal Colonization and Responsiveness to Inoculation in Cassava With Increasing Phosphorus Supply

2021 ◽  
Vol 12 ◽  
Author(s):  
Ricardo Alexander Peña Venegas ◽  
Soon-Jae Lee ◽  
Moses Thuita ◽  
Deusdedit Peter Mlay ◽  
Cargele Masso ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Field Trials ◽  
P Uptake ◽  
Fungal Colonization ◽  
P Availability ◽  
Terrestrial Plants ◽  
Soil Microbial ◽  
Arbuscular Mycorrhizal Fungal ◽  
P Supply

A vast majority of terrestrial plants are dependent on arbuscular mycorrhizal fungi (AMF) for their nutrient acquisition. AMF act as an extension of the root system helping phosphate uptake. In agriculture, harnessing the symbiosis can potentially increase plant growth. Application of the AMF Rhizophagus irregularis has been demonstrated to increase the yields of various crops. However, there is a paradigm that AMF colonization of roots, as well as the plant benefits afforded by inoculation with AMF, decreases with increasing phosphorus (P) supply in the soil. The paradigm suggests that when fertilized with sufficient P, inoculation of crops would not be beneficial. However, the majority of experiments demonstrating the paradigm were conducted in sterile conditions without a background AMF or soil microbial community. Interestingly, intraspecific variation in R. irregularis can greatly alter the yield of cassava even at a full application of the recommended P dose. Cassava is a globally important crop, feeding 800 million people worldwide, and a crop that is highly dependent on AMF for P uptake. In this study, field trials were conducted at three locations in Kenya and Tanzania using different AMF and cassava varieties under different P fertilization levels to test if the paradigm occurs in tropical field conditions. We found that AMF colonization and inoculation responsiveness of cassava does not always decrease with an increased P supply as expected by the paradigm. The obtained results demonstrate that maximizing the inoculation responsiveness of cassava is not necessarily only in conditions of low P availability, but that this is dependent on cassava and fungal genotypes. Thus, the modeling of plant symbiosis with AMF under different P levels in nature should be considered with caution.

scholarly journals Synergistic community responses of plants and arbuscular mycorrhizal fungi to extreme droughts in a cold-temperate grassland

2020 ◽  
Author(s):  
Wei Fu ◽  
Baodong Chen ◽  
Matthias Rillig ◽  
Wang Ma ◽  
Chong Xu ◽  
...  
Keyword(s):  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Community Dynamics ◽  
Environmental Changes ◽  
Environmental Filtering ◽  
Climate Extremes ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Temperate Grassland ◽  
Community Responses

Mutualistic associations between plants and arbuscular mycorrhizal (AM) fungi may have profound influences on their response to climate changes. Existing theories evaluate the effects of interdependency and environmental filtering on plant-AM fungal community dynamics separately; however, abrupt environmental changes such as climate extremes can provoke duo-impacts on the metacommunity simultaneously. Here, we experimentally tested the relevance of plant and AM fungal community responses to extreme drought (chronic or intense) in a cold temperate grassland. Irrespective of drought intensities, plant species richness and productivity responses were significantly and positively correlated with AM fungal richness and also served as best predictors of AM fungal community shifts. Notably, the robustness of this community synergism increased with drought intensity, likely reflecting increased community interdependence. Network analysis showed a key role of Glomerales in AM fungal interaction with plants, suggesting specific plant-AM fungal pairing. Thus, community interdependence may underpin climate change impact on plant-AM fungal diversity patterns in grasslands.

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