scholarly journals Glomalin – an interesting protein part of the soil organic matter

2020 ◽  
Vol 15 (No. 2) ◽  
pp. 67-74 ◽  
Author(s):  
Vítězslav Vlček ◽  
Miroslav Pohanka
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Arbuscular Mycorrhiza ◽  
Mycorrhizal Fungi ◽  
Biological Diversity ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Fulvic Acids ◽  
Soil Parameters ◽  
Citrate Buffer

The negative effects of the current agricultural practices include erosion, acidification, loss of soil organic matter (dehumification), loss of soil structure, soil contamination by risky elements, reduction of biological diversity and land use for non-agricultural purposes. All these effects are a huge risk to the further development of soil quality from an agronomic point of view and its resilience to projected climate change. Organic matter has a crucial role in it. Relatively significant correlations with the quality or the health of soil parameters and the soil organic matter or some fraction of the soil organic matter have been found. In particular, Ctot, Cox, humic and fulvic acids, the C/N ratio, and glomalin. Our work was focused on glomalin, a glycoprotein produced by the hyphae and spores of arbuscular mycorrhizal fungi (AMF), which we classify as Glomeromycota. Arbuscular mycorrhiza, and its molecular pathways, is not a well understood phenomenon. It appears that many proteins are involved in the arbuscular mycorrhiza from which glomalin is probably one of the most significant. This protein is also responsible for the unique chemical and physical properties of soils and has an ecological and economical relevance in this sense and it is a real product of the mycorrhiza. Glomalin is very resistant to destruction (recalcitrant) and difficult to dissolve in water. Its extraction requires specific conditions: high temperature (121°C) and a citrate buffer with a neutral or alkaline pH. Due to these properties, glomalin (or its fractions) are very stable compounds that protect the soil aggregate surface. In this review, the actual literature has been researched and the importance of glomalin is discussed.  

Arbuscular mycorrhizal fungi contribute to 13C and 15N enrichment of soil organic matter in forest soils

2009 ◽  
Vol 41 (4) ◽  
pp. 858-861 ◽  
Author(s):  
Paulina Etcheverría ◽  
Dries Huygens ◽  
Roberto Godoy ◽  
Fernando Borie ◽  
Pascal Boeckx
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Arbuscular Mycorrhizal Fungi ◽  
Forest Soils ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
15N Enrichment

scholarly journals The effects of arbuscular mycorrhizal fungi (AMF) and Rhizophagus irregularis on soil microorganisms assessed by metatranscriptomics and metaproteomics

2019 ◽  
Author(s):  
D.R. Lammel ◽  
D. Meierhofer ◽  
P. Johnston ◽  
S. Mbedi ◽  
M.C. Rillig
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Soil Aggregation ◽  
Rhizophagus Irregularis ◽  
Soil Microbial ◽  
Nutrient Mineralization ◽  
Metabolic Functions

AbstractArbuscular mycorrhizal fungi (AMF) form symbioses with approximately 80% of plant species and potentially benefit their hosts (e.g. nutrient acquisition) and the soil environment (e.g. soil aggregation). AMF also affect soil microbiota and soil multifunctionality. We manipulated AMF presence (via inoculation of non-sterile soil with Rhizophagus irregularis and using a hyphal compartment design) and used RNA-seq and metaproteomics to assess AMF roles in soil. The results indicated that AMF drove an active soil microbial community expressing transcripts and proteins related to nine metabolic functions, including the metabolism of C and N. We suggest two possible mechanisms: 1) the AMF hyphae produce exudates that select a beneficial community, or, 2) the hyphae compete with other soil microbes for available nutrients and consequently induce the community to mineralize nutrients from soil organic matter. We also identified candidate proteins that are potentially related to soil aggregation, such as Lpt and HSP60. Our results bridge microbial ecology and ecosystem functioning. We show that the AMF hyphosphere contains an active community related to soil respiration and nutrient cycling, thus potentially improving nutrient mineralization from soil organic matter and nutrient supply to the plants.

scholarly journals Characterization of Soil Organic Matter Individual Fractions (Fulvic Acids, Humic Acids, and Humins) by Spectroscopic and Electrochemical Techniques in Agricultural Soils

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1067
Author(s):  
Aleksandra Ukalska-Jaruga ◽  
Romualda Bejger ◽  
Guillaume Debaene ◽  
Bożena Smreczak
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Substances ◽  
Humic Acids ◽  
Agricultural Soils ◽  
Fulvic Acids ◽  
Sorption Properties ◽  
Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of soil organic matter fractions (humic substances (HS): fulvic acids-FAs, humic acids-HAs, and humins-HNs), which are the most reactive soil components. A wide spectrum of spectroscopic (UV–VIS and VIS–nearIR), as well as electrochemical (zeta potential, particle size diameter, and polydispersity index), methods were applied to find the relevant differences in the behavior, formation, composition, and sorption properties of HS fractions derived from various soils. Soil material (n = 30) used for the study were sampled from the surface layer (0–30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO. Our study showed that significant differences in the molecular structures of FAs, Has, and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic–aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic, and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl, and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles. The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition, and sorption properties, which reflects their binding potential to other molecules depending on soil properties resulting from their type. The determined properties of individual HS fractions are presented as averaged characteristics over the examined soils with different physico-chemical properties.

Effects of temperature rise (+5°C) on millet growth and mycorrhization and soil microbial community of culture

2021 ◽  
Author(s):  
Sally Diatta ◽  
Hassna Mboup-Founoune ◽  
Sidy Diakhaté ◽  
Diégane Diouf
Keyword(s):  
Microbial Community ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Crop Yields ◽  
Pennisetum Glaucum ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Sub Saharan Africa ◽  
Soil Fertility Management ◽  
Vegetation Growth

<p>Our planet is marked by significant climatic variations, particularly with the warming of temperatures and the variation in rainfall. In sub-Saharan Africa, the impacts of climate change are more pronounced because agriculture is highly dependent on climate, hence its vulnerability to climate variability (Vanluwe et al., 2011). In the context of changing environmental conditions, the use of innovative agricultural practices to contribute to plant adaptation is necessary to support food security challenges. Agroecological practices to improve crop yields and sustainable soil fertility management. Soil is the main reservoir of biodiversity as it hosts a very high diversity of interacting living species, which can be distinguished according to their size, macrofauna, mesofauna and microorganisms that constitute a particularly important component of soil (Brady and Weil, 2002), particularly for the provision of ecosystem services to humans. This work is therefore interested in studying the contribution of arbuscular mycorrhizal fungi (AMF) to the growth of millet (<em>Pennisetum glaucum</em>) under warmer temperature conditions and the behaviour of microbial community in soil of millet growing.</p><p>Millet is grown in a plant climate chamber and inoculated with a selected mycorrhizal strain.  These millet growing conditions were carried out in two different temperatures: 32°C (normal temperature) and 37°C (warmer temperature).</p><p>The results showed that in conditions of warmer temperature the inoculation induced a significant vegetative growth of millet even with a low intensity of mycorrhization and so it improves microbial nutrient mineralization mediate vegetation growth.</p><p>In soil of millet growing, a significant increase in microbial biomass with 42.7 in warmer temperature condition compared to control temperature 16.7. Results of DGGE shows also a soil abundance and SMB diversity of the total fungal community was noted under warmer temperature condition.</p><p>This study showed that climate variation may affect soil symbiosis but not the potential for promoting plant growth of fungi. The use of arbuscular mycorrhizal fungi on the one hand as a biofertilizer can be an alternative in the context of reducing chemical inputs in agriculture and developing ecologically intensive agriculture (EIA) and on the other hand an adaptive practice  to apprehend the predicted climate changes.</p>

scholarly journals Harnessing Soil Microbes to Improve Plant Phosphate Efficiency in Cropping Systems

Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 127 ◽  
Author(s):  
Arjun Kafle ◽  
Kevin Cope ◽  
Rachel Raths ◽  
Jaya Krishna Yakha ◽  
Senthil Subramanian ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Soil Microbes ◽  
Cropping Systems ◽  
Agricultural Practices ◽  
Arbuscular Mycorrhizal ◽  
Acid Synthesis ◽  
Phosphate Solubilizing Bacteria ◽  
Strong Adsorption ◽  
Phosphate Solubilizing ◽  
Complete Dependence

Phosphorus is an essential macronutrient required for plant growth and development. It is central to many biological processes, including nucleic acid synthesis, respiration, and enzymatic activity. However, the strong adsorption of phosphorus by minerals in the soil decreases its availability to plants, thus reducing the productivity of agricultural and forestry ecosystems. This has resulted in a complete dependence on non-renewable chemical fertilizers that are environmentally damaging. Alternative strategies must be identified and implemented to help crops acquire phosphorus more sustainably. In this review, we highlight recent advances in our understanding and utilization of soil microbes to both solubilize inorganic phosphate from insoluble forms and allocate it directly to crop plants. Specifically, we focus on arbuscular mycorrhizal fungi, ectomycorrhizal fungi, and phosphate-solubilizing bacteria. Each of these play a major role in natural and agroecosystems, and their use as bioinoculants is an increasing trend in agricultural practices.

scholarly journals Ectomycorrhizas accelerate decomposition to a greater extent than arbuscular mycorrhizas in a northern deciduous forest

2021 ◽  
Author(s):  
Alexis Carteron ◽  
Fabien Cichonski ◽  
Etienne Laliberté
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Deciduous Forest ◽  
Arbuscular Mycorrhizal ◽  
Am Fungi ◽  
Arbuscular Mycorrhizas ◽  
Fungal Hyphae ◽  
Organic Horizons ◽  
Temperate Deciduous ◽  
Temperate Deciduous Forests

AbstractIt has been proposed that ectomycorrhizal (EcM) fungi slow down decomposition by competing with free-living saprotrophs for organic nutrients and other soil resources (known as the “Gadgil effect”), thereby increasing soil carbon sequestration. As such, this Gadgil effect should depend on soil organic matter age and quality, but this remains unstudied. In addition, the Gadgil effect is not expected to occur in arbuscular mycorrhizal (AM) forests since AM fungi cannot access directly nutrients from soil organic matter, yet few direct comparisons between EcM and AM forests have been made. We performed a two-year reciprocal decomposition experiment of soil organic horizons (litter - L, fragmented - F, humic - H) in adjacent temperate deciduous forests dominated by EcM or AM trees. Litterbags were made of different mesh sizes allowing or excluding ingrowth of external fungal hyphae, which are primarily mycorrhizal in these forests other than for the most-recent superficial litter horizon. As expected, organic matter originating from deeper horizons and from EcM forests was of lower quality (e.g. higher lignin to nitrogen ratios) and decomposed more slowly. However, contrary to the Gadgil effect, organic matter exposed to external fungal hyphae (i.e. primarily mycorrhizal) actually decomposed faster in both forest types, and this effect was strongest in EcM forests, particularly in the F horizon. Unexpectedly, organic matter decomposition was faster in EcM than in AM forests, regardless of organic matter origin. Overall, our study reinforces the view that temperate EcM forests store greater amounts of soil organic carbon than AM forests, but suggests that this is due to factors other than the Gadgil effect.

scholarly journals Effect of Phosphate Fertilizer and Arbuscular Mycorrhizal Fungi on The Nutrient, Phosphateuptake and in Vitro Digestibility of Alfalfa

2016 ◽  
Vol 40 (3) ◽  
pp. 203 ◽  
Author(s):  
Bambang Suwignyo ◽  
Bela Putra ◽  
Nafiatul Umami ◽  
Cahyo Wulandari ◽  
Ristianto Utomo
Keyword(s):  
Organic Matter ◽  
Mycorrhizal Fungi ◽  
Dry Matter ◽  
Arbuscular Mycorrhizal ◽  
Phosphate Fertilizer ◽  
P Uptake ◽  
In Vitro Digestibility ◽  
P Fertilizer ◽  
Total P

This study aimed to determine the effect of arbuscular mycorrhizal fungi (AMF) and phosphate (P) fertilizer on the nutrient content, phosphate uptake and in vitro digestibility of alfalfa (Medicago sativa L.).The research was conducted at green house of Forage and Pastures Science Laboratory, Faculty of Animal Science Universitas Gadjah Mada. The experiment was arranged in Completely Randomized Design using 3x4 factorial patterns with four replications. The first factor was dosage of phosphate fertilizer SP 36 (0, 60, and 120 kg/ha). Second factor was the dosage of AMF (0, 0.8, 1.6, and 2.4kg/ha). The variable measured was nutrient contents (crude protein, dry matter, and organic matter), total P uptake and dry matter and organic matter in vitro digestibility. The results showed that the interaction of AMF and P fertilizer had no significant effect on crude protein and total P uptake, but highly significant effect on the parameters of dry matter, organic matter and dry matter and organic matter in vitro digestibility. 

scholarly journals Large-scale genome sequencing of mycorrhizal fungi provides insights into the early evolution of symbiotic traits

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Shingo Miyauchi ◽  
Enikő Kiss ◽  
Alan Kuo ◽  
Elodie Drula ◽  
Annegret Kohler ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Transposable Elements ◽  
Genome Sequencing ◽  
Mycorrhizal Fungi ◽  
Large Scale ◽  
Terrestrial Ecosystems ◽  
Pathogenic Species ◽  
Fungal Genomes ◽  
Induced Genes

Abstract Mycorrhizal fungi are mutualists that play crucial roles in nutrient acquisition in terrestrial ecosystems. Mycorrhizal symbioses arose repeatedly across multiple lineages of Mucoromycotina, Ascomycota, and Basidiomycota. Considerable variation exists in the capacity of mycorrhizal fungi to acquire carbon from soil organic matter. Here, we present a combined analysis of 135 fungal genomes from 73 saprotrophic, endophytic and pathogenic species, and 62 mycorrhizal species, including 29 new mycorrhizal genomes. This study samples ecologically dominant fungal guilds for which there were previously no symbiotic genomes available, including ectomycorrhizal Russulales, Thelephorales and Cantharellales. Our analyses show that transitions from saprotrophy to symbiosis involve (1) widespread losses of degrading enzymes acting on lignin and cellulose, (2) co-option of genes present in saprotrophic ancestors to fulfill new symbiotic functions, (3) diversification of novel, lineage-specific symbiosis-induced genes, (4) proliferation of transposable elements and (5) divergent genetic innovations underlying the convergent origins of the ectomycorrhizal guild.

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