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Floral traits, including floral display and nutritional rewards from pollen and nectar, drive pollinator visitation. Even within a single plant species, environmental factors can influence the quality and quantity of floral resources. Yet, the ecological interactions driving this variation in floral resources, especially those belowground, remain unknown. Here, we investigate how soil microbial community composition and nutrient availability, specifically distinct arbuscular mycorrhizal fungi (AMF) species and phosphorus (P) supply, affect plant growth, AMF traits, floral traits, and how that, in turn, affects bee visitation. We found that increased AMF richness of functional diversity enhanced floral display (flower size and number) and rewards (nectar volume and pollen protein) and increased bee visitation. Using structural equation modeling, we found that AMF associations could boost bee visitation by enhancing flower size. However, trade-offs occur; flower size correlates negatively with root colonization but positively with hyphal length, suggesting that AMF traits drive the effects of AMF on flower growth. Overall, the effect of AMF on floral traits and bee visitation was not homogenous; instead, AMF trait differences interact with P supply, resulting in varying effects on floral traits and subsequently bee foraging dynamics. These results highlight that focusing on beneficial belowground interactions could provide an opportunity to bolster bee visitation.

Plants and mycorrhizal fungi form mutualistic relationships that affect how resources flow between organisms and within ecosystems. Common mycorrhizal networks (CMNs) could facilitate preferential transfer of carbon and limiting nutrients, but this remains difficult to predict. Do CMNs favour fungal resource acquisition at the expense of plant resource demands (a fungi-centric view), or are they passive channels through which plants regulate resource fluxes (a plant-centric view)? We used stable isotope tracers (13CO2 and 15NH3), plant traits, and mycorrhizal DNA to quantify above- and below-ground carbon and nitrogen transfer between 18 plant species along a 520-km latitudinal gradient in the Pacific Northwest, USA. Plant functional type and tissue stoichiometry were the most important predictors of interspecific resource transfer. Of ‘donor’ plants, 98% were 13C-enriched, but we detected transfer in only 2% of ‘receiver’ plants. However, all donors were 15N-enriched and we detected transfer in 81% of receivers. Nitrogen was preferentially transferred to annuals (0.26 ± 0.50 mg N per g leaf mass) compared with perennials (0.13 ± 0.30 mg N per g leaf mass). This corresponded with tissue stoichiometry differences. Synthesis Our findings suggest that plants and fungi that are located closer together in space and with stronger demand for resources over time are more likely to receive larger amounts of those limiting resources. Read the free Plain Language Summary for this article on the Journal blog.

Arbuscular mycorrhizal fungi (AMF) transport substantial plant carbon (C) that serves as a substrate for soil organisms, a precursor of soil organic matter (SOM), and a driver of soil microbial dynamics. Using two-chamber microcosms where an air gap isolated AMF from roots, we 13CO2-labeled Avena barbata for 6 wk and measured the C Rhizophagus intraradices transferred to SOM and hyphosphere microorganisms. NanoSIMS imaging revealed hyphae and roots had similar 13C enrichment. SOM density fractionation, 13C NMR, and IRMS showed AMF transferred 0.77 mg C g-1 of soil (increasing total C by 2% relative to non-mycorrhizal controls); 33% was found in occluded or mineral-associated pools. In the AMF hyphosphere, there was no overall change in community diversity but 36 bacterial ASVs significantly changed in relative abundance. With stable isotope probing (SIP)-enabled shotgun sequencing, we found taxa from the Solibacterales, Sphingobacteriales, Myxococcales, and Nitrososphaerales (ammonium oxidizing archaea) were highly enriched in AMF-imported 13C (> 20 atom%). Mapping sequences from 13C-SIP metagenomes to total ASVs showed at least 92 bacteria and archaea were significantly 13C-enriched. Our results illustrate the quantitative and ecological impact of hyphal C transport on the formation of potentially protective SOM pools and microbial roles in the AMF hyphosphere soil food web.

The effects of rhizosphere microorganisms on plant growth and the associated mechanisms are a focus of current research, but the effects of exogenous combined inoculation with arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on seedling growth and the associated rhizosphere microecological mechanisms have been little reported. In this study, a greenhouse pot experiment was used to study the effects of single or double inoculation with AM fungi (Funneliformis mosseae) and two PGPR (Bacillus sp., Pseudomonas sp.) on the growth of tobacco seedlings, together with high-throughput sequencing technology to reveal associated rhizosphere microecological mechanisms. All inoculation treatments significantly increased the aboveground dry weight; root dry weight; seedling nitrogen, phosphorus, and potassium uptake; plant height; stem thickness; maximum leaf area; chlorophyll content; total root length, surface area, and volume; and average root diameter. The highest values for these indices were observed in the combined treatment of F. mosseae and Pseudomonas sp. SG29 (A_SG29). Furthermore, the A_SG29 treatment yielded the highest diversity indexes and largest percentages of significantly enriched bacterial taxa, and significantly promoted the colonization of AMF in tobacco roots and Pseudomonas in rhizosphere soil. Differential metabolic-pathway predictions using PICRUSt2 showed that the A_SG29 treatment significantly increased the metabolic pathway richness of tobacco rhizosphere microorganisms, and significantly up-regulated some metabolic pathways that may benefit plant growth. Co-inoculation with F. mosseae and Pseudomonas sp. SG29 promoted tobacco-seedling growth by significantly improving rhizosphere microbial communities' structure and function. In summary, the combined inoculation of AMF and SG29 promotes tobacco seedling growth, optimizes the rhizosphere microbial community's structure and function, and serves as a sustainable microbial co-cultivation method for tobacco seedling production. [ABSTRACT FROM AUTHOR]

AbstractThe olive tree is an emblematic fruit tree species of the Mediterranean basin facing drought. In this study, we estimated the effects of inoculating one-year-old olive trees of the ‘Moroccan Picholine’ and ‘Arbequina’ cultivars with arbuscular mycorrhizal fungi (M) and plant growth-promoting-bacteria (B), both individually and in combination (M + B), focusing on morpho-physiological, anatomical and nutritional changes. We evaluated these effects under two levels of water stress: well-watered conditions (WW) at 75% field capacity (FC) and drought stress (DS) at 25% FC. However, biofertilizers mitigated these effects by improving growth parameters. The M + B application increased growth parameters by 35%, 48%, 24%, and 36% in ‘Moroccan Picholine’, and by19%, 24%, 38%, and 64% in ‘Arbequina’ for the number of leaves, number of buds, growth rate, and leaf area, respectively, compared to the stressed controls. In summary, the results show that the ‘Moroccan Picholine’ cultivar has greater resistance to drought than ‘Arbequina’, making it a promising choice for arid conditions. These findings highlight the potential of biofertilizers as a sustainable approach to enhancing olive tree resilience in arid regions, contributing to agricultural sustainability. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing interest in leveraging Scientific Machine Learning (SciML) techniques to address challenges in solving Partial Differential Equations (PDEs). This study focuses on forecasting the growth of microbial populations in soil using a novel numerical methodology, the Physics-Informed Neural Network (PINN). This approach is crucial in overcoming the inherent challenges associated with the general unculturability of soil bacteria. PINNs can be used to model the growth of bacterial and fungal populations, considering environmental factors like temperature, solar radiation, air humidity, soil hydration status, and external weather conditions. In this paper, some stability issues related to the mathematical model have been analyzed. Moreover, by utilizing field data and applying equations that describe the biological mechanisms of microbial growth, a PINN was trained to predict the development of the microbiota over time. The results demonstrate that the use of PINNs for studying microbial growth and evolution is a promising tool for enhancing agriculture, optimizing cultivation processes, and facilitating efficient resource management. [ABSTRACT FROM AUTHOR]

This study aimed to explore the diversity, root morphology, and colonization of arbuscular mycorrhizal fungi (AMF) associated with eight medicinal plants of the Lamiaceae family. Rhizospheric soil and root samples were collected from eight species of Lamiaceae plants for AMF analysis. The results indicate that root colonization was not directly related to the number of AMF spores in the rhizosphere. However, a significant correlation was found between the percentage of root colonization and the number of AMF species present in the individual plants. The highest percentage of colonization (86.67 ± 1.92%) and the greatest number of AMF species were observed in Micromeria fructicosa, while the lowest colonization (27.67 ± 6.22%) was recorded in Mentha arvensis. The highest spore count was recorded in Thymus vulgaris (120 ± 27.01), whereas the lowest was found in Melissa officinalis (84 ± 17.20). Among the identified AMF species, Glomus was the most dominant, representing 35.7% of all AMF species across the eight medicinal plants. The maximum AMF spore density was observed in M. fructicosa and lowest in M. arvensis. The study suggests that AMF can significantly enhance medicinal plant growth by ensuring a consistent supply of nutrients and water, thereby supporting the sustainable cultivation of medicinal plants to meet the growing demand. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are associated with plant roots and exhibit beneficial impacts such as stress tolerance, better nutrient uptake, and water absorption. These functions have opened the door to research opportunities for considering other fungi associated with AMF on the root rhizosphere. This study aimed to characterize fungal isolates associated with rhizospheric indigenous AMF from different plant species, i.e., banana, grass, and papaya, in three agroecologies, i.e., Mwea, Mitunguu, and Juja in Central Kenya. A total of 30 fungal isolates were isolated from soil samples through the pour plate technique. The isolates had diverse microscopic morphological characteristics, describable in form, margin, color, size, and surface. Physiochemical parameters showed varied growth at different pH values, temperatures, and salinity levels. Optimal growth appeared at pH 7.0, 30-35 °C, and 0-0.5 M NaCl salinity. The internal transcribed spacer (ITS) and AMF subunit sequences showed a level of diversity similar to Aspergillus spp. Ajellomyces spp., Fusarium spp., Trichoderma spp., Penicillium spp., Glomus spp., and Diversispora spp. In conclusion, there was a symbiotic relationship between AMF and other fungal isolates. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal (AM) fungi are important plant symbionts that provide plants with nutrients and water as well as support plant defences against pests and disease. Consequently, they present a promising alternative to using environmentally damaging and costly fertilisers and pesticides in agricultural systems. However, our limited understanding of how agricultural practices impact AM fungal diversity and functions is a key impediment to using them effectively in agriculture. We assessed how organic and conventional agricultural management systems shaped AM fungal communities. We also investigated how AM fungal communities derived from these agricultural management systems affected crop biomass and development. Six soil samples from five organically and five conventionally managed agricultural sites were used to cultivate Sorghum bicolor. Plant growth, plant nutrient concentrations and AM fungal colonisation rates were analysed alongside DNA metabarcoding of community composition. We observed that soil from conventional agricultural fields resulted in a pronounced reduction in sorghum biomass (−53.6%) and a significant delay in flowering compared to plants grown without AM fungi. Sorghum biomass was also reduced with soil from the organic system, but to a lesser extent (−30%) and without a delay in flowering. Organic systems were associated with a large proportion of AM fungal taxa (50.5% of VTs) not found in conventional systems, including Diversispora (r2 = 0.09, p < 0.001), Archaeospora (r2 = 0.07, p < 0.001) and Glomus (r2 = 0.25, p < 0.001) spp., but also shared a large proportion of taxa with conventional systems (42.3% of VTs). Conventional systems had relatively few unique taxa (7.2% of VTs). Our results suggest that conventional agricultural practices selected against AM fungi that were, in this context, more beneficial for host plants. In contrast, organic management practices mitigate this negative effect, likely due to the presence of specific key AM fungal taxa. However, this mitigation is only partial, as less beneficial AM fungal taxa still persist, probably due to abiotic factors associated with agricultural management and the sensitivity of AM fungi to these factors. This persistence explains why the effect is not entirely eradicated. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are commonly found in heavy metal-contaminated environments and form extraradical mycelium (ERM), but knowledge of their ecological functions is limited. In the present study, a soil column was filled with sterilized cadmium (Cd)-contaminated soil and contained an in-growth core for AMF-inoculated maize seedling growth. The in-growth core was static to maintain or rotated to disrupt ERM growth. Compared with the static treatment, the rotation treatment caused significant decreases in the content of glomalin-related soil protein (GRSP), the photosynthetic physiology of leaves, and maize growth, while increasing the Cd content in shoots and roots by 64 and 82%, respectively; additionally, the rotation treatment resulted in increases in the Cd concentration of the soil solution inside and outside the growth core by 30–38 and 17–52%, respectively, and Cd leaching loss by 29–39%. Moreover, the rotation treatment significantly altered the Cd forms in the soil solution and leachate, increasing the proportion of free Cd2+ by 0.8–2.1% and decreasing the proportions of CdSO4(aq) and CdOH+ by 6.1–56.1% and 26.1–48.7%, respectively. The structural equation model indicated that AMF directly and indirectly reduced maize Cd uptake and Cd leaching loss by decreasing Cd availability in the soil and soil solution through the GRSP secreted by ERM. Thus, AMF plays a crucial role in inhibiting Cd migration in soil through mycelial exudates. [ABSTRACT FROM AUTHOR]

Tuta absoluta (Lepidoptera: Gelechiidae) is one of the most significant invasive and destructive pests worldwide, causing serious economic losses to the tomato industry. Rhizosphere microorganism, such as arbuscular mycorrhizal fungi (AMF) and Pseudomonas bacteria, can interact with plants individually or collectively to improve plant growth and resistance to pests and disease. However, the effects of AMF, Pseudomonas, and their interactions on plant responses to insect herbivores remain unclear. A pot experiment was conducted to investigate the effects of single/dual inoculation with AMF (Funneliformis mosseae, M) and Pseudomonas putida (P) on the growth and defense of tomato variety Dafen (Solanum lycopersicum L.) in response to infestation by T. absoluta, as well as the growth, development, and enzyme activity of insect. The results showed that M, P, and MP promoted tomato growth by increasing nutrient concentrations, with the growth-promoting effect of dual-inoculation significantly surpassing that of single inoculation. M, P, and MP still improved tomato growth in T. absoluta infestation, with biomass increases of 57.34%, 54.46%, and 255.49%. M, P, and MP significantly increased the defense ability of tomato, with jasmonic acid concentrations increasing by 42.15%, 60.87% and 90.02%, and phenylalanine ammonia-lyase activity increasing by 47.40%, 47.68%, and 59.97%. The inoculation treatments inhibited the growth and development of T. absoluta, reduced its feeding, prolonged its growth and development, decreased egg weight, and increased the activity of protective and detoxifying enzymes. Overall, our results indicated that AMF and bacteria can stimulate each other, positively influence tomato growth and enhance resistance to T. absoluta. These findings indicate the feasibility of AMF and bacteria in combinations as potential biocontrol agents for the management of T. absoluta. [ABSTRACT FROM AUTHOR]

The study aimed to enhance the organic production of head lettuce using vermiwash and arbuscular mycorrhizal fungi (AMF), both individually and in combination, in the presence of compost. These treatments were evaluated for their effects on the growth, yield, quality and mineral content of head lettuce, compared to a control treatment of compost only. The results showed that all treatments involving vermiwash and AMF, either individually or together, significantly improved growth, yield and quality over compost alone. The combination of vermiwash and AMF with compost yielded the best results across all measured parameters. This study recommends using vermiwash and AMF together with compost as an effective approach to improving organic head lettuce production, which will increase profits for organic lettuce growers. HIGHLIGHTSVermiwash and AMF combined with compost significantly enhanced head lettuce growth and yield.The application of vermiwash and AMF led to better quality and mineral content in lettuce compared to compost-only treatment.The combination of vermiwash and AMF together outperformed their individual applications, showing a synergistic effect.The use of organic treatments (compost, vermiwash and AMF) aligns with sustainable agricultural practices.This study advocates for the combined use of vermiwash and AMF with compost to optimise organic head lettuce production.Vermiwash and AMF combined with compost significantly enhanced head lettuce growth and yield.The application of vermiwash and AMF led to better quality and mineral content in lettuce compared to compost-only treatment.The combination of vermiwash and AMF together outperformed their individual applications, showing a synergistic effect.The use of organic treatments (compost, vermiwash and AMF) aligns with sustainable agricultural practices.This study advocates for the combined use of vermiwash and AMF with compost to optimise organic head lettuce production. [ABSTRACT FROM AUTHOR]

The study aims to determine the optimal dose of olive mill wastewater (OMW) for maximum mycorrhization and to assess the biomass, physiological, and biochemical tolerance of mycorrhizal olive plants to stress induced by this wastewater. The study involved injecting Rhizophagus irregularis into young olive trees (Olea europaea L.) under greenhouse conditions. At rates of 100, 150, and 200 m³/ha, OMW is applied to the soil surrounding each olive tree. For comparison, a non-inoculated group was added as a control. Dry matter, mycorrhization rate, leaf relative water content (RWC), foliar nutrients (N, P, and K), and a number of physiological and biochemical parameters were among the variables that were assessed. When arbuscular mycorrhizal fungi and olive mill wastewater were combined at a rate of 100 m³/ha, the results showed significant increases in dry matter (22.5%), Leaf relative water content (16.32%), potassium levels (38.46%), stomatal conductance (30.4%), and photosynthesis compared to the control. However, high olive mill wastewater doses (150 and 200 m³/ha) caused water stress: Compared to nonmycorrhizal plants (NM), the decrease in mycorrhizal plants (M) was less pronounced. Leaf relative water content dropped by 14.9% and 21.27% in mycorrhizal plants and by 22.22% and 28.88% in non-mycorrhizal plants. Under these high doses of Olive mill wastewater, the mycorrhization rate dropped significantly by as much as 30% and 45% respectively. All OMW treatments increased proline and sugar content as stress responses. Consequently, our study reveals that the optimal application of 100 m³/ha of OMW, combined with Rhizophagus irregularis, enhances the growth and performance physiology of young olive plants while increasing mycorrhization rates, stomatal conductance, and photosynthetic efficiency. This synergy between OMW and AMF also promotes better plant resilience to water stress by activating biochemical mechanisms such as increased proline and sugar levels. Additionally, AMF mitigates the negative effects of high OMW doses, highlighting its crucial role in managing the risks associated with wastewater application. [ABSTRACT FROM AUTHOR]

Introduction: Arbuscular mycorrhizal fungi (AMF) can relieve manganese (Mn) phytotoxicity and promote plant growth under Mn stress, but their roles remain unclear. Methods: In this study, Lespedeza davidii inoculated with or without AMF (Glomus mosseae) under different Mn concentrations (0 mmol/L, 1 mmol/L, 5 mmol/L, 10 mmol/L, and 20 mmol/L) was cultivated via a pot experiment, and plant biomass, physiological and biochemical characteristics, manganese absorption, subcellular distribution, and chemical forms of Mn were examined. Results: The results showed that root biomass, stem biomass, leaf biomass, and total individual biomass decreased under high Mn concentrations (above 10 mmol/L), and the inoculated plants had higher biomass than the uninoculated plants. With the increasing Mn concentration, the contents of soluble sugar, soluble protein, free proline, superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) increased first and then decreased, while the malondialdehyde (MDA) content increased. The contents of soluble sugar, soluble protein, free proline, SOD, POD, and CAT in the inoculated group were higher than those in the uninoculated group at the Mn concentration of 20 mmol/L. The content of MDA in the inoculated plants was lower than that in the uninoculated plants. AMF inoculation enriched most of the manganese in the root system when compared with the non-mycorrhizal treatment. Subcellular distribution of Mn indicated that most of the Mn ions were stored in the cell wall and the vacuoles (the soluble fractions), and the proportion of Mn content in the cell wall components and the vacuole components in leaves in the inoculated group was higher than that in the uninoculated group. Furthermore, the proportions of Mn extracted using ethanol and deionized water in the uninoculated group in stems and roots were higher than those in the inoculated group, which suggested that AMF could convert Mn into inactive forms. Discussion: The present study demonstrated that AMF could improve the resistance of L. davidii to Mn toxicity by increasing the activity of antioxidant enzymes and altering the subcellular distribution and chemical forms of Mn. [ABSTRACT FROM AUTHOR]

Nuclear calcium (Ca2+) signaling is crucial for symbiotic interactions between legumes and beneficial microbes, such as rhizobia and arbuscular mycorrhizal fungi. The ion channels DMI1 and CNGC15 are key to generating repetitive nuclear Ca2+ oscillations. Despite more than 20 years of research on symbiotic nuclear Ca2+ spiking, important questions remain, including the exact function of the DMI1 channel. This review highlights recent developments that have filled knowledge gaps regarding the regulation of CNGC15 and its interplay with DMI1. We also explore new insights into the evolutionary conservation of DMI1-induced symbiotic nuclear Ca2+ oscillations and the roles of CNGC15 and DMI1 beyond symbiosis, such as in nitrate signaling, and discuss new questions this raises. As we delve deeper into the regulatory mechanisms and evolutionary history of these ion channels, we move closer to fully understanding the roles of nuclear Ca2+ signaling in plant life. [ABSTRACT FROM AUTHOR]

Soil amendments, including various types of fertilizers, are often used to control the uptake of heavy metals such as cadmium in cropping fields. The influence of these amendments on other members of the agroecosystem, such as arbuscular mycorrhizal fungi (AMF), remains less well investigated. Here, we established an experiment with the application of woody peat organic fertilizer and phosphate rock powder to examine its effects on AMF communities in two cadmium-contaminated vegetable crop fields (cucumber and pepper). We found that the application of phosphate rock powder enhanced soil phosphorus content, while the application of woody peat organic fertilizer enhanced soil nitrogen content, but neither influenced AMF abundance. We also found little influence of either amendment on measures of AMF diversity, except in one case where the Shannon index of diversity was lower in pepper fields amended with phosphate rock powder. We did, however, find significant shifts in the community composition and relative abundances of AMF taxa in the two vegetable fields, primarily as a result of shifts in the soil pH and nitrogen content. [ABSTRACT FROM AUTHOR]

Based on molecular phylogenetic analyses, and also considering morphological characters, four new families are separated from the family Glomeraceae within the order Glomerales and the class Glomeromycetes. The revised family Glomeraceae comprises only four genera: the type genus Glomus, Complexispora, Sclerocarpum and Simiglomus. Septoglomeraceae fam. nov. comprises, besides Septoglomus, Funneliformis, Funneliglomus, Blaszkowskia and Viscospora. Sclerocystaceae fam. nov. is represented by the type genus Sclerocystis but also by Halonatospora, Oehlia, Parvocarpum, Rhizoglomus and Silvaspora. Kamienskiaceae fam. nov. encompasses Kamienskia, Microkamienskia and Epigeocarpum. Finally, Dominikiaceae fam. nov. includes the genera Dominikia, Macrodominikia gen. nov., Microdominikia, Nanoglomus and Orientoglomus. The genera Oehlia and Halonatospora form two other clades well separated from Silvaspora, Sclerocystis and Rhizoglomus and might represent two further families within Glomerales. This deeper separation is, in our opinion, fully supported by molecular phylogeny, but in view of the low numbers of taxa, the separation is not yet proposed at this stage of research progress. [ABSTRACT FROM AUTHOR]

Aim: The unregulated use of rare earth elements, such as Europium (Eu), may result in their build-up in soils. Here, we investigated how Eu affects wheat growth, photosynthesis, and redox homeostasis and how Arbuscular mycorrhizal fungi (AMF) may influence these processes. Methods: The wheat plants were grown in soil with 1.09 mmol Eu3+/kg and/or AMF inoculation. The study is mainly based on a comprehensive examination of the detailed biochemical and metabolic mechanisms underlying the Eu stress mitigating impact of Eu by AMF in wheat plants. Results: Soil contamination with Eu significantly induced a reduction in biomass accumulation and photosynthesis-related parameters, including photosynthetic rate (61%) and chlorophyll content (24.6%). On the other hand, AMF could counteract Eu's induced growth and photosynthesis inhibition. Under Eu stress, AMF colonization significantly increased fresh and dry weights by 43% and 23.5%, respectively, compared to Eu treatment. AMF colonization also induced minerals (e.g., Ca, K, Zn, and N) uptake under control and Eu stress conditions. By bolstering the antioxidant defense mechanisms, such as ROS-scavenging metabolites (flavonoids and polyphenols), AMF mitigated Eu-induced oxidative damage. In terms of the primary metabolites, organic acids, essential amino acids, and unsaturated fatty acids were increased by AMF colonization, particularly under Eu stress conditions. Conclusion: Applying AMF is a workable approach for reducing Eu toxicity in wheat plants. [ABSTRACT FROM AUTHOR]

Background and aims: Vegetation patchiness is a distinctive feature of arid ecosystems that strongly shapes plant-soil interactions. While fertility islands are recognized as a critical plant legacy influencing ecosystem functioning, it is not clear whether there is a legacy associated with fungi symbionts in soils. We compared the legacies of arbuscular mycorrhizal fungi (AMF) and dark septate endophyte (DSE) inoculum potential in soil, to determine if they respond to the plant functional type (PFT, grasses and shrubs) and if they overlap spatially with the nutrient legacies. Methods: We estimated the soil inoculum potential of AMF and DSE and the soil organic carbon (C), phosphorus (P), and nitrogen (N) concentrations in the soil microsites occupied by the dominant grass and shrub species, and in bare soil microsites distributed in a 6-hectare grazing exclosure in the Patagonian steppe. Results: The AMF inoculum potential was higher in soil microsites conditioned by grasses than in microsites conditioned by shrubs. Instead, the DSE inoculum potential did not differ among microsites and was higher than that of AMF. Furthermore, C and P concentrations were higher in microsites conditioned by shrubs, contrary to AMF inoculum potential. Conclusion: We found that grasses and shrubs have decoupled soil legacies that may alleviate nutrient limitation. While shrubs increase nutrient concentrations, grasses increase AMF inoculum potential. Moreover, the homogeneous distribution of DSE inoculum potential highlights the need to further investigate the role of this group of fungi and its interactions with AMF and soil nutrients in the plant-soil interface. [ABSTRACT FROM AUTHOR]

Salinity, resulting from climate change and excessive mineral fertilization, burdens farmers and negatively impacts soil and water ecosystems in the Northeastern Nile Delta. Organic and biological approaches are crucial for addressing these issues. This study examined the effects of individual and combined inoculations with cyanobacteria, yeast, and Arbuscular Mycorrhizal Fungi (AMF), with or without K-Humate and reducing Nitrogen, phosphorus and potassium (NPK) mineral fertilizers application rates to crop quality of wheat and faba bean. In preliminary laboratory experiments, the interactive effects of these microbiomes on plant antioxidant and soil enzyme production were examined under salinity stress. Results showed that co-inoculation, especially with K-Humate, yielded superior outcomes compared to individual inoculations. These findings were validated by a field trial conducted in saline-alkaline soil in the Northeastern Nile Delta region. All biological treatments 25% of recommended doses, and enhancing salinity tolerance, increasing yield, and improving enhanced rhizosphere microbial activity, including soil enzyme activity, AMF colonization, spore density, and the total numbers of bacteria, cyanobacteria, and yeast. These effects were further amplified by K-Humate and were more pronounced with combined inoculations than with individual ones, leading to improved soil fertility and significant increases in both crop quantity and quality compared to control treatments. The triple treatment, combining cyanobacteria, yeast, and mycorrhizae in the presence of K-Humate while reducing the mineral NPK rate by 75%, achieved superior increases in the productivity of wheat grains and faba bean seeds, reaching 54.72% and 128.92%, respectively, compared to the 100% NPK mineral control. This treatment also significantly improved crop quality, with notable increases in nitrogen, potassium, phosphorus, and protein percentages in wheat grains and faba bean seeds. Microbiomes-interaction increased potassium uptake over sodium, enhancing the plant's potassium/sodium ratio and improving salt stress tolerance. This approach reduces reliance on costly mineral fertilizers, enabling bio-organic farming in marginal lands, optimizing resource utilization, and preserving natural resources. [ABSTRACT FROM AUTHOR]

Intensive agriculture often comes at the expense of soil health. A shift towards practices that foster soil health will support yield and defences against pests and diseases. Growing crops in monoculture is the standard in modern agriculture, though strip‐cropping, in which different crops are planted in strips, is a promising strategy in the transition towards sustainable agriculture. Increasing crop diversity is hypothesized to positively influence arbuscular mycorrhizal fungi (AMF), thereby enhancing soil health, but the mechanisms by which AMF‐plant symbioses contribute to higher yields and reduced pest populations in strip‐cropping systems remain unclear.We used a green‐house experiment with potato plants to explore the soil legacy effects of mono‐cropping versus strip‐cropping systems, AMF inoculation and aphid infestation on AMF root colonization, the induction of plant defences (untargeted LCMS‐based metabolomics), aphid population size and potato yield.We found that potato plants grown in strip‐cropping soil had higher AMF colonization than plants grown in mono‐cropping soil. Potato plants grown in strip‐cropping soil also had higher shoot nitrogen content, increased solamargine levels, and reduced aphid populations. AMF root colonization was only enhanced by the addition of commercial AMF in mono‐cropping soils. Potato plant metabolites were affected by strip‐cropping soil, including jasmonic acid (JA) derivatives. Structural equation models revealed that strip‐cropping soil directly reduced aphid populations and also had a negative direct effect on the JA precursor OPC‐8, and hydroxyJA‐glucosides, indicating complex effects of strip‐cropping soils on JA‐inducible plant defences. Indirect benefits of strip‐cropping soil and AMF inoculation on tuber yield were mediated by their direct positive effects on plant nitrogen content.Our results emphasize the potential of strip‐cropping to enhance AMF root colonization in the field. We show that soil legacy effects of strip‐cropping alter the plant metabolome in ways that suppress of aphid populations. Strip‐cropping legacy effects are the result of crop diversity, crop neighbour and edge effects resulting from crop management practices. While the mechanisms by which soil from strip‐cropping supresses pest populations still need to be identified, our study underscores the potential for strip‐cropping to enhance pest control and yield via soil mediated processes. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Enhancing herbal plant germination through biological priming is crucial under water stress conditions. This study investigated the effects of different biopriming techniques on the physiological and biochemical attributes of two lavender genotypes (English and French) under water stress induced by PEG-6000 (-1, -0.5, - 0.25, and 0 MPa) during 2022. Results indicated that the English genotype outperformed the French genotype regarding germination parameters and photosynthetic pigment content, while the French genotype exhibited higher activity levels of antioxidant enzymes. Under well-watered conditions, hydropriming (HP) and Azetobacter + Pseudomonas (AzPs) treatments led to the most excellent germination percentages and tallest seedlings in the English genotype. Hydropriming and AzPs treatments resulted in the most elevated levels of chlorophyll a, b, and total. Additionally, when subjected to water stress, the AzPs treatment showed the highest chlorophyll b and total. Proline content was found to vary between genotypes and treatments, with the highest mean associated with the English genotype and seed priming with AzPs + Arbuscular mycorrhizal fungi (AMF) under the highest level of water stress. The study suggests that bio-priming with biofertilizers and hydropriming can improve germination parameters and physiological characteristics, with individual biofertilizers being more effective than their combined application. Moreover, the English genotype exhibited superior features to the French genotype, and using of AMF and AzPs alone can enhance seed germination and improve the biochemical characteristics of lavender under water stress conditions. [ABSTRACT FROM AUTHOR]