Arbuscular Mycorrhizal Research Articles

NO3--N pulse supply caused by biodegradable plastics exacerbates Trifolium repens L. invasion.

The exacerbation of plant invasion by microplastics attracted widespread attention. Pulse resource hypothesis is popular theory to elucidate plant invasion. Our previous work demonstrated biodegradable microplastics (BMPs) could increase the arbuscular mycorrhizal fungi (AMF) colonization rate. Reportedly, AMF can enhance rhizobia colonization. Therefore, we infer the coexistence of BMPs with legumes may lead to an increased colonization of rhizobia with negative feedback regulation of N fixation. This could result in NO3--N pulse supply, thereby exacerbating plant invasion. Subsequently, a 60-day pot experiment was conducted using Trifolium repens L. as invasive plant and Oxalis corniculata L. as native plant, with 1% or 5% wt BMPs. AMF colonization, BMPs degradation, NO3--N content and pulse supply, rhizobia colonization, relative competitive intensity, replacement diagrams and NO3--N utilization were determined. The mechanism was clarified through heat map and structural equation model. The results reveal the greater the NO3--N consumption by BMPs, the more AMF promoted rhizobia colonization in T. repens, thereby the larger the pulse amplitude of NO3--N supply, then, the higher the NO3--N utilization rate of T. repens. It exacerbates T. repens invasion. This study clarifies effects of BMPs on rhizobia's N fixation, and enriches the evidence on mechanism of BMPs exacerbating plant invasion.

Arbuscular mycorrhizal fungi enhance drought resistance and alter microbial communities in maize rhizosphere soil

Although the benefits of inoculation with arbuscular mycorrhizal fungi (AMF) for mitigating drought stress and enhancing plant growth of host are well‐studied, our understanding of their interactions with soil attributes and rhizosphere microbial communities remains limited. In the present study, we conducted a pot experiment to explore how AMF affects maize growth, antioxidant activity, soil properties, and the rhizosphere microbial communities under drought stress. The results showed that AMF inoculation during drought stress resulted in improved maize seedling growth, significantly increasing plant biomass (42.7%), chlorophyll content (13.4%), and antioxidant capacity. It also enhanced soil nutrient availability and microbial biomass. We observed significant shifts in the structure and composition of the rhizosphere microbial community with AMF inoculation under drought conditions when compared to those under well-watered conditions. Significantly, bacterial diversity and composition showed greater sensitivity to drought stress than fungal communities. This was attributed to plants preferentially reducing the supply of carbon sources to bacterial rather than to fungal communities under drought conditions. AMF inoculation also enhanced the complexity (e.g., degree) and stability of the rhizosphere microbial ecological network, suggesting closer ecological interactions within the soil microbial community. Furthermore, bacterial diversity and richness played a more important role in soil function than those of fungal communities under drought stress, particularly with AMF inoculation. Overall, our findings suggest that AMF inoculation alters soil microbial diversity and interactions, highlighting their key roles in enhancing plant stress tolerance and mitigating the negative effects of drought on agricultural ecosystems.

Field inoculation with a local arbuscular mycorrhizal (AM) fungal consortium promotes sunflower agronomic traits without changing the composition of AM fungi coexisting inside the crop roots

Field inoculation with a local arbuscular mycorrhizal (AM) fungal consortium promotes sunflower agronomic traits without changing the composition of AM fungi coexisting inside the crop roots

Interactions of silicon and arbuscular mycorrhizal fungi on phosphorus uptake during rice vegetative growth

Interactions of silicon and arbuscular mycorrhizal fungi on phosphorus uptake during rice vegetative growth

Enhancement of alfalfa growth resistance by arbuscular mycorrhiza and earthworm in molybdenum-contaminated soils: From the perspective of soil nutrient turnover.

Molybdenum (Mo) acts as a crucial nutrient for plant development, yet excessive soil exposure can cause detrimental effects. Molybdenosis symptoms remain subtle in many plants, largely due to the safeguarding functions of soil organisms, the fundamental biological mechanisms lack clarity. In this study, we explored the potential mechanisms for amending Mo-exposed soils with soil microbe-arbuscular mycorrhizal fungi (AMF) and soil fauna, specifically earthworms, to enhance model plant-alfalfa growth resistance through soil nutrient turnover perspectives. Our findings illustrated that excessive Mo exposure disrupted soil nutrient turnover, manifesting as exacerbated microbial C and N metabolic limitations. Consequently, this interference intensified nutrient competition between alfalfa and soil microbes, thereby impeding alfalfa nutrient uptake and growth resistance. The synergistic application of AMF and earthworms alleviated microbial C (8.55% ∼ 28.23%) and N (11.14% ∼ 37.55%) metabolic limitations by modulating soil enzyme activities, particularly P-acquiring enzyme. This co-approach facilitated enhanced C and N accumulation in alfalfa, thus improving its growth resistance (24.15% ∼ 123.74%) under Mo exposure. Furthermore, in contrast to singular treatments, the combination of AMF and earthworms bolstered mutual Mo tolerance, amplifying biological benefits for alfalfa growth. Earthworms promoted AMF colonization and the secretion of glomalin-related soil proteins (GRSP), while AMF alleviated Mo accumulation and oxidative stress in earthworms. Additionally, the AMF-induced regulation of gut metabolism reduced earthworm mortality and minimized weight loss. Our study underscores the necessity of maintaining soil biodiversity when utilizing Mo fertilizers to mitigate the potential risks of Mo over-exposure affecting soil nutrient turnover and plant growth.

Response of root- and soil-associated AM fungi to nitrogen addition and simulated drought in a Chinese fir plantation

Response of root- and soil-associated AM fungi to nitrogen addition and simulated drought in a Chinese fir plantation

Effect of AM fungi on the growth and powdery mildew development of Astragalus sinicus L. under water stress

Effect of AM fungi on the growth and powdery mildew development of Astragalus sinicus L. under water stress

Metabolomics analysis reveals crucial effects of arbuscular mycorrhizal fungi on the metabolism of quality compounds in shoots and roots of Camellia sinensis L

Metabolomics analysis reveals crucial effects of arbuscular mycorrhizal fungi on the metabolism of quality compounds in shoots and roots of Camellia sinensis L

Synergistic effect of arbuscular mycorrhizal fungi, biochar and seaweed extract for improving the copper tolerance in hemp

Synergistic effect of arbuscular mycorrhizal fungi, biochar and seaweed extract for improving the copper tolerance in hemp

An assessment of plant growth and physiological responses in annual crops grown in P deficient soils inoculated with indigenous arbuscular mycorrhizal fungi.

The influence of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and physiology of Phaseolus vulgaris L. and Zea mays L. in the Brazilian tropical seasonal dry forest is not well known. We examined the effects of indigenous AMF species inoculation on these two annual crops at phosphorus-deficient soils under glasshouse conditions. The AMF species used as inoculum were collected from the root zone of Mimosa tenuiflora, a native plant of the Caatinga ecoregion. The inoculum was propagated in plastic pots with Trifolium sp. as the host plant. We investigated the effect of four treatments: (1) Control- non-inoculated; (2) Acaulospora inoculum- inoculation with A. tuberculata; (3) Gigaspora inoculum- inoculation with G. gigantea; and (4) Mixed inoculum- inoculation with both Acaulospora and Gigaspora species. We found that inoculation with the indigenous AMF community enhanced plant dry biomass, plant P concentration, root colonization, and physiological responses for both model plants. This study highlighted the importance of exploring the P molecule as an integral element in plant development and presents the AMF inoculation as an efficient alternative to overcome low-P conditions, leading to improved nutrient acquisition in low-fertility soils, better growth conditions through enhanced physiological responses, and ultimately increased plant dry biomass.

AM fungus plant colonization rather than an Epichloë endophyte attracts fall armyworm feeding.

Most cold-season grasses can be colonized by belowground arbuscular mycorrhizal (AM) fungi and foliar grass endophytes (Epichloë) simultaneously while also be attacked by insect herbivores. The colonization of AM fungi or the presence of grass endophytes is associated with increased resistance by the host plant. However, studies on how these two symbionts affect host plants and mitigate insect pest attack are currently lacking. In a glasshouse study we investigated the effects of an AM fungus (Acaulospora delicata), a foliar grass endophyte (Epichloë), and the insect pest Spodoptera frugiperda (fall armyworm, FAW) on plant growth, defense enzyme activity, and hormone concentrations of the important pasture grass Lolium perenne. Additionally, we assessed the selective behavior of FAW larvae in response to these interactions using olfactometer tests. Our results showed that the AM fungus and its co-colonization with Epichloë endophytes increased aboveground biomass, while Epichloë endophytes alone had no significant impact on ryegrass aboveground biomass. In contrast, FAW reduced aboveground biomass. The Epichloë endophytes and FAW significantly decreased the mycorrhizal colonization rate by 21.67% and 30.16%, respectively. Interestingly, compared to non-mycorrhizal plants, AM fungus colonized plants were more attractive to FAW larvae feeding, and the defense enzyme activity was not discernibly affected by any experimental treatments. The interactions of the AM fungus and Epichloë endophyte increased the jasmonic acid concentrations by 24.29% and decreased trasylol activity by 11.75% in the host plants under FAW attack. Neither the AM fungus nor Epichloë endophyte influenced the relative growth rate (RGR) of FAW. Overall, the AM fungus had a greater positive effect on plant growth than the Epichloë endophyte, regardless of FAW larvae infestation.

Ecological filters shape arbuscular mycorrhizal fungal communities in the rhizosphere of secondary vegetation species in a temperate forest.

The community assembly of arbuscular mycorrhizal fungi (AMF) in the rhizosphere results from the recruitment and selection of different AMF species with different functional traits. The aim of this study was to analyze the relationship between biotic and abiotic factors and the AMF community assembly in the rhizosphere of four secondary vegetation (SV) plant species in a temperate forest. We selected four sites at two altitudes, and we marked five individuals per plant species at each site. Soil rhizosphere samples were collected from each SV plant species, during the rainy and dry seasons. Soil samples from the rhizosphere of each plant species were analyzed for AMF spores, organic matter (OM), pH, soil moisture, and available phosphorus, and nitrogen. Three ecological filters influenced the AMF community assembly: host plant identity, abiotic factors, and AMF species co-occurrence. This assembly consisted of 61 AMF species, with different β-diversity values among plant species across seasons and altitudes. Canonical correspondence analysis revealed that AMF community composition is linked to OM and available P and N, with only a few AMF species co-occurring, while most do not. Our study highlights how ecological filters shape AMF structure, which is essential for understanding how soil and environmental factors affect AMF in SV plant species across seasons and altitudes.

Interaction between arbuscular mycorrhizal fungi and dark septate endophytes in the root systems of Populus euphratica and Haloxylon ammodendron under different drought conditions in Xinjiang, China

Background and AimsArbuscular mycorrhizal fungi (AMF) and dark septate endophytes (DSE) are known to enhance the tolerance of host plants to biotic and abiotic stresses, but the mechanism of their interaction under natural conditions has not been extensively studied.MethodsWe analyzed the endophytic fungal diversity and colonization characteristics in the typical desert plants Populus euphratica and Haloxylon ammodendron and the relationship between them and environmental factors.ResultsExcept for DSE in the roots of H. ammodendron, the colonization rates of AMF and DSE were significantly positively correlated with drought severity. The abundance of AMF and DSE under medium and mild drought conditions was greater than that under severe drought conditions. The root colonization rate and abundance of AMF were lower than those of DSE under the same drought conditions. The species diversity and abundance of AMF and DSE in P. euphratica were greater than those in H. ammodendron. AMF were more susceptible to soil factors such as soil water content, soil nitrogen and phosphorus content, and urease, whereas DSE were more affected by pH.ConclusionDrought stress has different effects on AMF and DSE in the roots of P. euphratica and H. ammodendron. DSE have a greater advantage in extremely arid environments. This study demonstrates the interaction between AMF and DSE with the host plants P. euphratica and H. ammodendron as well as their effects on the adaptation of host plants to the desert environment, which can provide a basis for strengthening desert vegetation management.

The assembly of plant communities in relation to overlap in mycorrhizal and pathogenic root fungi

Abstract Plant species commonly associate with symbiotic arbuscular mycorrhizal (AM) and pathogenic root fungi, with many plants overlapping in their fungal community compositions. Overlap in AM fungi could promote coexistence by favouring competitively inferior or rare plants, or through the establishment of common mycorrhizal networks. Coexistence could also, however, be impeded if shared AM fungi disproportionately benefit competitively superior or abundant plant species. Overlap in pathogenic root fungi among closely growing plant species should increase the likelihood that an uninfected plant becomes infected, leading to reduced coexistence. Using vegetation plot data from an old‐field plant community along with high‐throughput sequence data on AM and pathogenic root fungal associations, we conducted three specific evaluations. First, we used null models to determine whether estimated overlap in AM or pathogenic root fungi among coexisting plant species was higher or lower than expected by chance. Second, we assessed whether estimated overlap in AM and pathogenic fungi differed between positively co‐occurring and negatively co‐occurring plant species. Third, we examined whether variation in plot‐level plant species richness was explained by the degree of estimated overlap in AM and pathogenic root fungi among those species. We found no evidence that estimated overlap in AM or pathogenic root fungal communities was higher or lower than expected under our null model. Additionally, positively and negatively co‐occurring pairs of plant species did not differ in their estimated overlap in either group of fungi. However, plant species richness was significantly higher in plots where plants were estimated to overlap more in AM fungi and significantly lower in plots where plant species were estimated to overlap more in pathogenic root fungi. Our results suggest that overlap in root fungal associations among plant species appears to be predictive of plant species richness, and therefore the assembly of plant communities. Read the free Plain Language Summary for this article on the Journal blog.

Insights and applications of Arbuscular mycorrhizal fungi

In natural ecosystems, rhizospheric soils are teeming with diverse biological organisms that enhance plant growth, nutrient absorption, stress tolerance and disease prevention. Among these organisms, arbuscular mycorrhizal (AM) fungi are particularly significant due to their symbiotic relationships with plants. Their application extends beyond natural ecosystems into agricultural and horticultural practices, where they contribute to improved soil health and plant productivity. This review discusses the benefits of incorporating AM fungi into modern agricultural systems to improve nutrient uptake, soil structure and plant resilience. It emphasizes the need for strategies to restore and maximize AM fungi's efficacy, ensuring sustainability and productivity in agriculture, industry and natural ecosystems.

Standardization of Organic Production Systems for Lettuce and Pokchoi in Nilgiris

An experiment was conducted to standardize the cultivation of Lettuce (Lactuca sativa) and Pokchoi under organic production system at Horticultural Research Station, Ooty during 2022-23. These exotic vegetables are grown for salad purpose for different dishes and consumed as raw in most of the Indian and European cuisine. The consumption of these exotic crops has increased considerably and farmers cultivate the crop on everyday harvest basis. The organic farming practices will help the farmers to fetch good remuneration as well to produce and practice Good Agricultural Practices so as to feed the consumers. An experimental field trial was conducted at Wood house farm of Horticultural research station in Lettuce var. Green and Pokchoi var. Chacko. A total of five treatments viz., T1 – Control, T2 – Recommended dose of fertilisers, T3 – organic package followed by farmers, T4 - Package of practices based on recommendations of NOFRC (Nammazhvar Organic Farming Research Centre, TNAU, Coimbatore) and T5 - Modified Package of practices based on recommendations of NOFRC were imposed with four replications. The results revealed that Lettuce and Pokchoi grown under modified organic package of practices (Green manuring and biofumigation with mustard + FYM @ 25 tonnes per ha + top dressing vermicompost @ 2 tonnes per ha + 3% panchagavya foliar spray + 2 kg each of azospirillum + phosphobacteria + potashbacteria+ AM fungi) + need based application of biocontrol agents+ organic weedicide (vinegar 10% + common salt 5%) recorded significance with regard to morphological and yield parameters. Organic cultivation of Lettuce and Pokchoi plants proved significance when compared to cultivation with inorganic fertilizers and recorded a fresh weight of 176.3 g and 230.6 g respectively. The leaf quality of Lettuce and Pokchoi was also superior for use as salad and the organic production system thus can be popularized as a means of environmental sustainability.

The Role of Organic and Biological Fertilizers on the Growth, Yield of Mung Bean Plant and Water Use Efficiency in Water Deficit Conditions in Northern Iran

ABSTRACT Knowledge of the yield of short-season crops under insufficient irrigation is of particular importance for regions that face water deficit during the plant growth period. This experiment was carried out by investigating the effects of organic and biological fertilizers on the growth, yield and water use efficiency of mung bean plants under water deficit conditions and the traits affecting grain yield. Experiment treatments including irrigation at three levels (100, 80 and 60% of water requirement (WR)), organic fertilizer (0 and 16 and 24 t/ha manure) and biofertilizer (control, Arbuscular mycorrhizal (AM) fungi and enterobacter (EB)). In stress and non-stressed conditions, the application of AM and organic fertilizer has increased the number of seeds and the number of plant pods. The highest weight of one hundred seeds was obtained in the condition of 80% WR and application of organic and biological fertilizer. The number of primary branches was higher with the use of EB, but the highest number of secondary branches was observed in the plant with AM. The highest plant height, biological yield and seed were observed in the condition of 100% WR and 24 t/ha of organic fertilizer and application of AM and EB. The highest water use efficiency was obtained with irrigation of 80% WR and application of AM and 24 t/ha of organic fertilizer, as well as irrigation of 60% WR and application of AM and 24 t/ha of organic fertilizer. The use of organic fertilizer along with biofertilizers in stress conditions has increased the measured traits, and this increase was more in severe stress with AM than EB fertilizer. The results of the path analysis showed that the weight of one hundred seeds, the number of seeds in the pod and biological yield are the most direct effects on seed yield.

Decoding the Dialog Between Plants and Arbuscular Mycorrhizal Fungi: A Molecular Genetic Perspective

Arbuscular mycorrhizal (AM) symbiosis, a mutually beneficial interaction between plant roots and AM fungi, plays a key role in plant growth, nutrient acquisition, and stress tolerance, which make it a major focus for sustainable agricultural strategies. This intricate association involves extensive transcriptional reprogramming in host plant cells during the formation of arbuscules, which are specialized fungal structures for nutrient exchange. The symbiosis is initiated by molecular signaling pathways triggered by fungal chitooligosaccharides and strigolactones released by plant roots, which act as chemoattractants and signaling molecules to promote fungal spore germination, colonization, and arbuscule development. Calcium spiking, mediated by LysM domain receptor kinases, serves as a critical second messenger in coordinating fungal infection and intracellular accommodation. GRAS transcription factors are key components that regulate the transcriptional networks necessary for arbuscule development and maintenance, while small RNAs (sRNAs) from both plant and fungi, contribute to modifications in gene expression, including potential bidirectional sRNA exchange to modulate symbiosis. Understanding the molecular mechanisms related to AM symbiosis may provide valuable insights for implementation of strategies related to enhancing plant productivity and resilience.

Isolation and characterization of arbuscular mycorrhiza from a newly developed L J farm at village Dumana, Viramgam, Gujarat

Mycorrhiza in general and arbuscular mycorrhiza in particular are the most important terrestrial fungi that evolved with the evolution of land and plants and became a part and parcel of the plant's growth and development. It is so important for plant nutrition that its density and diversity were studied worldwide in different habitats, niches and climates. In the present study, a spore density of 1.6 to 4.04 per g of soil was observed in a semi-arid region; agroclimatic zone V of Gujarat at Dumana L J Farm, Viramgam. Nine different species of endomycorrhizae were characterized; however, species of Glomus and Acaulospora were dominant taxa. Because there is little taxonomic diversity in such a large group of mycorrhizal fungi, it is crucial to analyze local populations that have adapted to different environments. Depending on the climate, each species may have a significant amount of genetic variation. The result shows the spore density in a developing plantation field, which was earlier mainly used for the cultivation of a local variety of cotton. Since there is no such report on the density and diversity of endomycorrhiza from this region, this primary study will serve as a baseline for the comparison of the spore density of future studies of the region/field in different plants and seasons.

Mutual Relations Between Arbuscular Mycorrhizal Fungi and Ralstonia solanacearum in Potato Brown Rot Disease

Abstract Potato brown rot disease can devastate potato production. Arbuscular mycorrhizal fungi (AMFs) are known to boost crop output. This study examines the interaction between AMFs and Ralstonia solanacearum, focusing on their effects on tuber yield and brown rot incidence. AMF increased the tuber yield by 68% (P = 0.03) in sandy soil and 30% (P = 0.047) in clay soil, along with an increase in HCO₃⁻ in sandy soil by 56% (P = 0.001) and a 24% increase in clay soil (P = 0.002). A 12% decrease in soil organic matter from 1.37 to 1.20% (P = 0.044) was recorded in sandy soil. AMF increased the pathogen populations in the rhizosphere from 3.2 to 7.8 (log CFU/g, P = 0.02) in sandy soil without a significant increase in Area Under the Disease Progression Curve. The pathogen decreased AMF colonization by 47% in sandy soil and 48% in clay soil, as well as sporulation by 63% in sandy and 57% in clay soils respectively (P < 0.05 for all). It decreased the densities of phosphate-solubilizing bacteria from 6.19 up to 5.39 (P = 0.001) in sandy soil and from 6.04 to 5.16 (P = 0.008) in clay soil. Additionally, the pathogen decreased the silicate-solubilizing bacteria from 6.94 to 5.32 (P < 0.001) in sandy and from 6.82 up to 6.17 (P = 0.04) in clay soils respectively. In conclusion, while AMF significantly increased potato yield, it is not recommended for soils infested with R. solanacearum due to the potential increase in disease risk. Graphical Abstract