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Fertilizers and plant protection chemicals have played crucial role in modern agriculture. However, their excessive and imbalanced use over decades has resulted in the degradation and deterioration of soil health. The sustainability of agricultural systems largely depends on improving soil health. In this context, the arbuscular mycorrhizal fungi (AMF) association is a well-known interaction among plant microbial symbiotic associations that plays a multifunctional role in maintaining plant-soil health. More than 90% of terrestrial crop plants, including cultivated cotton, have a mutualistic symbiotic association with AMF. Symbiosis provides several benefits, such as the acquisition of mineral nutrients (primarily phosphorus), protection against biotic and abiotic stresses, and improved yield and fiber quality, contributing to the growth and development of the host plant. Under controlled conditions, the percent root length colonization of cotton was 50 to 70%, indicating the potential of AMF as a biological agent and plant growth promoter for sustainable cotton production. This review provides an updated and comprehensive overview of cotton-mycorrhizal symbiosis and its benefits. [ABSTRACT FROM AUTHOR]

Both biotic and abiotic stress factors play an important role in reducing the growth and productivity of many crops. In this study, the effects of arbuscular mycorrhizal (AM) fungi and biochar (Bc) were investigated against Verticillium dahliae (Vd) disease in pepper plants grown under salt stress. These effects were evaluated on enzyme activities, salt tolerance, disease severity, plant growth and physiological characteristics. In this study, pepper was treated with 2% biochar, Funneliformis mosseae (Fm), Vd and different concentrations of salt (0 mM, 50 mM, 100 mM, 150 mM). The interaction of Fm and 2% Bc significantly increased the morphological parameters of the plant and the plant tolerated salt and Vd under combined high stress conditions of biotic (Vd) and abiotic (salt) stresses. It was also shown that Fm had a different effect than Bc on the membrane injury index (MII; %) and had a significant effect on leaf relative water content (LRWC; %). In addition, Vd increased mycorrhizal reliance, with the higher spore density of AMF higher disease severity observed in treatments involving Fm and Fm + Bc. Furthermore, phenol and antioxidant values were altered in Vd treatments, while Fm decreased CAT enzyme activation. Therefore, this study supports that AMF + biochar used in sustainable agriculture increases plant resistance to the soil pathogen (V. dahliae) and the salt stresses. [ABSTRACT FROM AUTHOR]

Soil salinization, especially in arid and semi-arid regions, is one of the major abiotic stresses that affect plant growth. To mediate and boost plant tolerance against this abiotic stress, arbuscular mycorrhizal fungi (AMF) symbiosis is commonly thought to be an effective tool. So, the main purpose of this study was to estimate the role of AMF (applied as a consortium of Claroideoglomus etunicatum, Funneliformis mosseae, Rhizophagus fasciculatum, and R. intraradices species) symbiosis in mitigating deleterious salt stress effects on the growth parameters (shoot length (SL), root length (RL), shoot dry weight (SDW), root dry weight (RDW), root surface area (RSA), total root length (TRL), root volume (RV), root diameter (RD), number of nodes and leaves) of Cenchrus ciliaris L. plants through improved accumulations of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll), proline and phenolic compounds. The results of this experiment revealed that the roots of C. ciliaris plants were colonized by AMF under all the applied salinity levels (0, 75, 150, 225, and 300 mM NaCl). However, the rate of colonization was negatively affected by increasing salinity as depicted by the varied colonization structures (mycelium, vesicles, arbuscules and spores) which were highest under non-saline conditions. This association of AMF induced an increase in the growth parameters of the plant which were reduced by salinity stress. The improved shoot/root indices are likely due to enhanced photosynthetic activities as the AMF-treated plants showed increased accumulation of pigments (chlorophyll a, chlorophyll b and total chlorophyll), under saline as well as non-saline conditions, compared to non-AMF (N-AMF) plants. Furthermore, the AMF-treated plants also exhibited enhanced accumulation of proline and phenolic compounds. These accumulated metabolites act as protective measures under salinity stress, hence explaining the improved photosynthetic and growth parameters of the plants. These results suggest that AMF could be a good tool for the restoration of salt-affected habitats. However, more research is needed to check the true efficacy of different AMF inoculants under field conditions. [ABSTRACT FROM AUTHOR]

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production. [ABSTRACT FROM AUTHOR]

Background: Arbuscular mycorrhizal fungi (AMF) form mutualistic partnerships with approximately 80% of plant species. AMF, and their diversity, play a fundamental role in plant growth, driving plant diversity, and global carbon cycles. Knowing whether AMF are sexual or asexual has fundamental consequences for how they can be used in agricultural applications. Evidence for and against sexuality in the model AMF, Rhizophagus irregularis, has been proposed. The discovery of a putative mating-type locus (MAT locus) in R. irregularis, and the previously suggested recombination among nuclei of a dikaryon R. irregularis isolate, potentially suggested sexuality. Unless undergoing frequent sexual reproduction, evolution of MAT-locus diversity is expected to be very low. Additionally, in sexual species, MAT-locus evolution is decoupled from the evolution of arbitrary genome-wide loci. Results: We studied MAT-locus diversity of R. irregularis. This was then compared to diversification in a phosphate transporter gene (PTG), that is not involved in sex, and to genome-wide divergence, defined by 47,378 single nucleotide polymorphisms. Strikingly, we found unexpectedly high MAT-locus diversity indicating that either it is not involved in sex, or that AMF are highly active in sex. However, a strongly congruent evolutionary history of the MAT-locus, PTG and genome-wide arbitrary loci allows us to reject both the hypothesis that the MAT-locus is involved in mating and that the R. irregularis lineage is sexual. Conclusion: Our finding shapes the approach to developing more effective AMF strains and is highly informative as it suggests that introduced strains applied in agriculture will not exchange DNA with native populations. [ABSTRACT FROM AUTHOR]

Mangroves, despite thriving at the fringes of habitat tolerance in coastal regions, stand out as one of the world's most highly productive ecosystems. This study delves into the remarkable symbiotic relationship between mangroves and arbuscular mycorrhizal fungi (AMF). Specifically, it assesses seasonal diversity in six true mangrove species and four associated species, situated in Henry's Island, Bakkhali, India. Spore density and root colonization were examined across different seasons. The highest spore density was observed in Heritiera fomes (a timber-producing mangrove) during the post-monsoon season, followed by pre-monsoon and monsoon periods. Root colonization was notably prominent in Ceriops tagal (Indian mangrove), Bruguira gymnorrhiza (Oriental mangrove), and Sonneratia alba (flowering evergreen mangrove) during both pre- and postmonsoon seasons. This study unveiled a rich fungal diversity, with a total of 60 AMF species belonging to 13 genera. Among these, the genus Glomus emerged as the dominant group, with species such as G. deserticola along with another genus Rhizophagus intraradics displaying widespread distribution. Notably, Glomus consistently ranked as the most prevalent genus throughout the year, indicating its remarkable adaptability and strong dispersal capacity in both true and associate mangrove plant species. This research sheds light on the seasonal dynamics of AMF associations in mangrove ecosystems, emphasizing the significance of Glomus as a key player in this symbiotic relationship. These findings contribute to our understanding of the ecological intricacies within mangrove habitats and highlight the adaptability of certain AMF genera to varying environmental conditions. [ABSTRACT FROM AUTHOR]

Dry evergreen Afromontane forests (DAF) once covered most of the Ethiopian highlands. Currently, they are found as a few patches. DAF restoration is a national forest restoration priority in Ethiopia. It has also been identified to be among global ecosystem restoration priorities. There are sufficient data to show DAF restoration from the soil seed bank or seed rain is hardly possible. Planting trees from multiple provenances is important to restore climate-resilient DAF. Therefore, DAF restoration cannot be achieved through natural regeneration alone and must be accomplished by planting characteristic DAF tree species. The poor soil moisture and nutrient conditions in Ethiopia's dry highlands result in low native tree seedling survival and growth. Hence, proper preparation of the planting sites and after-planting seedling care for at least two years is a reliable mechanism for achieving successful survival and growth. Along with seedling care after planting, four additional mechanisms discussed in this review (i.e. the use of nurse trees/shrubs, design of nursery practices, inoculation with arbuscular mycorrhizal fungi, and application of biochar) have also been shown to be useful. However, they cannot substitute for proper planting site preparation and post-planting seedling care. The complementary use of these five mechanisms could further enhance success. However, there are more questions than answers regarding the effectiveness of the five mechanisms discussed. We hope this review will motivate researchers to engage further to answer some of the important questions regarding restoration success. [ABSTRACT FROM AUTHOR]

Abstract Background Arbuscular mycorrhizal fungi (AMF) form mutualistic partnerships with approximately 80% of plant species. AMF, and their diversity, play a fundamental role in plant growth, driving plant diversity, and global carbon cycles. Knowing whether AMF are sexual or asexual has fundamental consequences for how they can be used in agricultural applications. Evidence for and against sexuality in the model AMF, Rhizophagus irregularis, has been proposed. The discovery of a putative mating-type locus (MAT locus) in R. irregularis, and the previously suggested recombination among nuclei of a dikaryon R. irregularis isolate, potentially suggested sexuality. Unless undergoing frequent sexual reproduction, evolution of MAT-locus diversity is expected to be very low. Additionally, in sexual species, MAT-locus evolution is decoupled from the evolution of arbitrary genome-wide loci. Results We studied MAT-locus diversity of R. irregularis. This was then compared to diversification in a phosphate transporter gene (PTG), that is not involved in sex, and to genome-wide divergence, defined by 47,378 single nucleotide polymorphisms. Strikingly, we found unexpectedly high MAT-locus diversity indicating that either it is not involved in sex, or that AMF are highly active in sex. However, a strongly congruent evolutionary history of the MAT-locus, PTG and genome-wide arbitrary loci allows us to reject both the hypothesis that the MAT-locus is involved in mating and that the R. irregularis lineage is sexual. Conclusion Our finding shapes the approach to developing more effective AMF strains and is highly informative as it suggests that introduced strains applied in agriculture will not exchange DNA with native populations.

Mangroves, despite thriving at the fringes of habitat tolerance in coastal regions, stand out as one of the world’s most highly productive ecosystems. This study delves into the remarkable symbiotic relationship between mangroves and arbuscular mycorrhizal fungi (AMF). Specifically, it assesses seasonal diversity in six true mangrove species and four associated species, situated in Henry’s Island, Bakkhali, India. Spore density and root colonization were examined across different seasons. The highest spore density was observed in Heritiera fomes (a timber-producing mangrove) during the post-monsoon season, followed by pre-monsoon and monsoon periods. Root colonization was notably prominent in Ceriops tagal (Indian mangrove), Bruguira gymnorrhiza (Oriental mangrove), and Sonneratia alba (flowering evergreen mangrove) during both pre- and post-monsoon seasons. This study unveiled a rich fungal diversity, with a total of 60 AMF species belonging to 13 genera. Among these, the genus Glomus emerged as the dominant group, with species such as G. deserticola along with another genus Rhizophagus intraradics displaying widespread distribution. Notably, Glomus consistently ranked as the most prevalent genus throughout the year, indicating its remarkable adaptability and strong dispersal capacity in both true and associate mangrove plant species. This research sheds light on the seasonal dynamics of AMF associations in mangrove ecosystems, emphasizing the significance of Glomus as a key player in this symbiotic relationship. These findings contribute to our understanding of the ecological intricacies within mangrove habitats and highlight the adaptability of certain AMF genera to varying environmental conditions.

Arbuscular mycorrhizal fungi (AMF) serve as both plant symbionts and allies in resisting pathogens and environmental stresses. Mycorrhizal colonization of plant roots can influence the outcomes of plant-pathogen interactions by enhancing specific host defense mechanisms. The transcriptional responses induced by AMF in virus-infected plants remain largely unexplored. In the presented study, we employed a comprehensive transcriptomic approach and qPCR to investigate the molecular determinants underlying the interaction between AMF and potato virus Y (PVY) in Solanum tuberosum L. Our primary goal was to identify the symbiosis- and defense-related determinants activated in mycorrhizal potatoes facing PVY. Through a comparative analysis of mRNA transcriptomes in experimental treatments comprising healthy and PVY-infected potatoes colonized by two AMF species, Rhizophagus regularis or Funneliformis mosseae, we unveiled the overexpression of genes associated with mycorrhiza, including nutrient exchange, lipid transfer, and cell wall remodeling. Furthermore, we identified several differentially expressed genes upregulated in all mycorrhizal treatments that encoded pathogenesis-related proteins involved in plant immune responses, thus verifying the bioprotective role of AMF. We investigated the relationship between mycorrhiza levels and PVY levels in potato leaves and roots. We found accumulation of the virus in the leaves of mycorrhizal plants, but our studies additionally showed a reduced PVY content in potato roots colonized by AMF, which has not been previously demonstrated. Furthermore, we observed that a virus-dependent reduction in nutrient exchange could occur in mycorrhizal roots in the presence of PVY. These findings provide an insights into the interplay between virus and AMF.Key message: The article, based on the results of transcriptomic analysis, identifies the symbiosis-related and defense-related determinants activated in mycorrhizal potatoes infected by potato virus Y (PVY). [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are widespread obligate symbionts of plants. This dynamic symbiosis plays a large role in successful plant performance, given that AMF help to ameliorate plant responses to abiotic and biotic stressors. Although the importance of this symbiosis is clear, less is known about what may be driving this symbiosis, the plant's need for nutrients or the excess of plant photosynthate being transferred to the AMF, information critical to assess the functionality of this relationship. Characterizing the AMF community along a natural plant productivity gradient is a first step in understanding how this symbiosis may vary across the landscape. We surveyed the AMF community diversity at 12 sites along a plant productivity gradient driven by soil nitrogen availability. We found that AMF diversity in soil environmental DNA significantly increased along with the growth of the host plants Acerrubrum and A. saccharum., a widespread tree genus. These increases also coincided with a natural soil inorganic N availability gradient. We hypothesize photosynthate from the increased tree growth is being allocated to the belowground AMF community, leading to an increase in diversity. These findings contribute to understanding this complex symbiosis through the lens of AMF turnover and suggest that a more diverse AMF community is associated with increased host–plant performance. [ABSTRACT FROM AUTHOR]

Recent agricultural research has prioritized the development of environmentally friendly management strategies to ensure food security, among which the application of biostimulants such as brown algae extracts, arbuscular mycorrhizal fungi (AMF), and their combination are included. The experimental protocol was based on the factorial combination of two planting times (4 May and 1 June) and seven biostimulant treatments (three brown algae species, Cystoseria tamariscifolia—C.t.; Fucus vesiculosus—F.v.; Padina pavonica—P.p.; arbuscular mycorrhizal fungi—AMF; C.t. + AMF; F.v. + AMF; P.p. + AMF) plus an untreated control. The earlier transplant resulted in a higher yield, due to the higher number of fruits per plant, and a higher plant fresh and dry biomass. The treatments with P.p. and F.v. extracts and the combination P.p. + AMF led to the highest yields (56.7 t ha−1), mainly due to the highest fruit number per plant. The earlier planting time led to higher values of dry residue, soluble solids, firmness, and colour component 'a'. The highest values of fruit dry residue were recorded under the F.v. and P.p. extracts, and the combinations F.v. + AMF and P.p. + AMF, the highest soluble solid content with P.p. treatment, and firmness under P.p. + AMF. The highest levels of 'L' and 'a' fruit colour components were obtained under the P.p. extract treatment, of 'b' upon the application of P.p. and F.v. extract, and AMF + P.p. and AMF + F.v. The later planting time led to significantly higher values of the antioxidant parameters, as did the application of the P.p. extract and P.p. + AMF. CAT activity was more intense corresponding to the later tomato crop cycle, P.p. extract, and AMF + P.p. Overall, our study highlights the potential of biostimulants, particularly brown algae extracts and their combination with AMF, to improve tomato yield, antioxidant properties, and biochemical activities. [ABSTRACT FROM AUTHOR]

Background: Salinity stress remains a chronic threat to pulses productivity in India. Arbuscular mycorrhizal (AM) fungi play a major role which influences plant growth, nutrient uptake and contributes to ecosystem processes under salt stress. The present study aims, to demonstrate the impact of Glomus mosseae (Gm), on physio-biochemical attributes of mungbean exposed to salinity. Methods: Two highly tolerant, two moderately susceptible and two highly susceptible mungbean lines were subjected to salinity stress alone and in presence of Gm under greenhouse. Result: Results revealed that Gm alleviates the salinity stress related alterations by improving the nutrient uptake and by balancing the ratio between K:Na, which impact directly the osmoregulation of the plants. Mycorrhiza inoculation also increased the proline content (23%), water-use efficiency (38%) and activity of different antioxidant enzymes in a significant manner providing efficient protection against salinity stress. All these positive impacts of Gm were duly reflected in a significant increase in grain yield (more than 2 fold increase) in mungbean. Interestingly, salt-induced retarded growth and decline in other biochemical parameters in susceptible lines recorded remarkable recovery following Gm inoculation. [ABSTRACT FROM AUTHOR]

Panax notoginseng is a highly valued perennial medicinal herb in China and is widely used in clinical treatments. The main purpose of this study was to elucidate the changes in the composition of P. notoginseng saponins (PNSs), which are the main bioactive substances, triggered by arbuscular mycorrhizal fungi (AMF) via ultrahigh-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC–ESI–MS/MS). A total of 202 putative terpenoid metabolites were detected, of which 150 triterpene glycosides were identified, accounting for 74.26% of the total. Correlation analysis, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS–DA) of the metabolites revealed that the samples treated with AMF (group Ce) could be clearly separated from the CK samples. In total, 49 differential terpene metabolites were identified between the Ce and CK groups, of which 38 and 11 metabolites were upregulated and downregulated, respectively, and most of the upregulated differentially abundant metabolites were mainly triterpene glycosides. The relative abundances of the two major notoginsenosides (MNs), ginsenosides Rd and Re, and 13 rare notoginsenosides (RNs), significantly increased. The differential saponins, especially RNs, were more easily clustered into one branch and had a high positive correlation. It could be concluded that the biosynthesis and accumulation of some RNs share the same pathways as those triggered by AMF. This study provides a new way to obtain more notoginsenoside resources, particularly RNs, and sheds new light on the scientization and rationalization of the use of AMF agents in the ecological planting of medicinal plants. [ABSTRACT FROM AUTHOR]

Vegetation restoration and microbial reclamation of mining subsidence area is the key spot to construct green mine.The effects of Arbuscular Mycorrhizal Fungi (AMF) and re-vegetation types on the ecological chemometric characteristics of the plant-litter-soil continuum and leaf nutrient resorption are still unclear, but are important for illuminating nutrient cycling and sustainable development after ecological restoration in arid coal mining subsidence areas in Northwest China. Five types of restored vegetation and the 0～10 cm soil of the corresponding vegetation were selected for study in the reclamation of 10 years of inoculation with AMF and the control area—Amorpha fruticosa, Hippophae rhamnoides, Xan-thoceras sorbifolium, Cerasus humilis and Cerasus szechuanica.The intention was to explore the influences of inoculum and re-vegetation type on C, N and P contents and ecological stoichiometric ratios, nutrient recovery rates, and nutrient limitation within the plant-litter-soil continuum. Compared with the national level, the average nutrient content of the five restored vegetation organs showed the characteristics of higher C, lower P and lower N. The decomposition of the litter and plant growth were limited by the deficiency of soil N.Redundancy analysis indicates that the main soil factors affecting plant ecological stoichiometry were soil organic carbon, P, easily extracta-ble-glomalin-related soil protein and positive correlation between soil nutrients and leaf nutrient resorption mediated by mycorrhizae.AMF inoculation enhanced plant and soil nutrient content, N and P recovery rates and C:N, reduced vegetation N:P, which in turn alleviated plant N limitation, increased plant growth rate supporting the restoration of revegetation and promoting nutrient cycling along the continuum.On the other hand, the nutrient content, stability and growth rate of the inoculated nitrogen-fixing vegeta-tion in different artificially reconstructed vegetation of Amorpha fruticose and Hippophae rhamnoides were high. Ecological stoichiometry and nutrient recovery characteristics of the plant-litter-soil continuum pre-dicted soil nitrogen-limited sustainable ecological restoration in subsidence areas, while inoculation with AMF promoted the potential of sustainable ecological restoration in subsidence areas.

The relationship between biodiversity and ecosystem functioning strengthens with ecosystem age. However, the interplay between the plant diversity - ecosystem functioning relationship and Glomeromycotinian arbuscular mycorrhizal fungi (AMF) community assembly has not yet been scrutinized in this context, despite AMF's role in plant survival and niche exploration. We study the development of AMF communities by disentangling soil- and plant-driven effects from calendar year effects. Within a long-term grassland biodiversity experiment, the pre-existing plant communities of varying plant diversity were re-established as split plots with combinations of common plant and soil histories: split plots with neither common plant nor soil history, with only soil but no plant history, and with both common plant and soil history. We found that bulk soil AMF communities were primarily shaped by common soil history, and additional common plant history had little effect. Further, the steepness of AMF diversity and plant diversity relationship did not strengthen over time, but AMF community evenness increased with common history. Specialisation of AMF towards plant species was low throughout, giving no indication of AMF communities specialising or diversifying over time. The potential of bulk soil AMF as mediators of variation in plant and microbial biomass over time and hence as drivers of biodiversity and ecosystem relationships was low. Our results suggest that soil processes may be key for the build-up of plant community-specific mycorrhizal communities with likely feedback effects on ecosystem productivity, but the plant-available mycorrhizal pool in bulk soil itself does not explain the strengthening of biodiversity and ecosystem relationships over time. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is a vital nutrient element that is essential for plant growth and development, and arbuscular mycorrhizal fungi (AMF) can significantly enhance P absorption. The phosphate transporter protein 1 (PHT1) family mediates the uptake of P in plants. However, the PHT1 gene has not yet been characterized in Salvia miltiorrhiza. In this study, to gain insight into the functional divergence of PHT1 genes, nine SmPHT1 genes were identified in the S. miltiorrhiza genome database via bioinformatics tools. Phylogenetic analysis revealed that the PHT1 proteins of S. miltiorrhiza, Arabidopsis thaliana, and Oryza sativa could be divided into three groups. PHT1 in the same clade has a similar gene structure and motif, suggesting that the features of each clade are relatively conserved. Further tissue expression analysis revealed that SmPHT1 was expressed mainly in the roots and stems. In addition, phenotypic changes, P content, and PHT1 gene expression were analyzed in S. miltiorrhiza plants inoculated with AMF under different P conditions (0 mM, 0.1 mM, and 10 mM). P stress and AMF significantly affected the growth and P accumulation of S. miltiorrhiza. SmPHT1;6 was strongly expressed in the roots colonized by AMF, implying that SmPHT1;6 was a specific AMF-inducible PHT1. Taken together, these results provide new insights into the functional divergence and genetic redundancy of the PHT1 genes in response to P stress and AMF symbiosis in S. miltiorrhiza. [ABSTRACT FROM AUTHOR]

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The effect of inoculation of a combination of the arbuscular mycorrhizal fungus of Glomus and Acaulospora on micropropagated banana plantlets cultivar Raja from Bali during the acclimatization phase was investigated. The experiment was conducted at the Experimental Station of the Faculty of Agriculture, Udayana University, Denpasar, Bali, Indonesia, over the period of March to June 2022. The objective of this research was to evaluate the impact of various doses of mycorrhizae on the growth of tissue culture banana plantlets that had undergone acclimatization for a period of six weeks. A total of five different doses of mycorrhiza were applied to the acclimatized plantlets, namely M0=without mycorrhiza and M5=5g mycorrhiza.kg-1, M10=10 g mycorrhiza.kg-1, M15=15 g mycorrhiza.kg-1, M20=20 g mycorrhiza.kg-1. A significant effect was discovered at M15; however, compared to M20, M20 gave better results for root length and fresh weight of the above-ground part, indicating the best dose was 20 g mycorrhiza kg-1. This study concluded that mycorrhiza has a very significant role in supporting the growth of micro propagated banana plantlets at post-acclimatization. Variables observed, such as the average number of leaves, stem diameter, above-ground plant fresh and dry weight, and root fresh and dry weight, increased with the application of AMF (Glomus and Acaulospora). [ABSTRACT FROM AUTHOR]

Finding environmentally friendly solutions for crop growth and productivity has been gaining more attention recently. This meta-analysis aims to understand the combined application of arbuscular mycorrhizal fungi (AMF) and hydroponic systems compared to AMF in conventional (soil) systems. The analysis of up-to-date studies revealed that the root colonization, calculated as the proportion of colonized root segments relative to the total root length, by AMF in conventional (soil-based) culture exceeded hydroponic (or soilless) culture systems by 16.8%. The mean root colonization by AMF was determined to be 52.3% in hydroponic systems and 61.1% in conventional systems. Within hydroponic systems, the root colonization ranged from 2% to 20% after 10 days of inoculation, and notably, it exceeded 50% after 30 to 65 days, depending on the growing substrate and species. Under hydroponics, AMF application had a higher (compared to none-inoculated) positive effect on crop biomass and yield than fruit and leaf quality (antioxidants, phenols, and sugars) as well as leaf nutrients. However, AMF do not always have the potential to improve crop growth, quality and productivity in hydroponics. Among the studies analyzed in this review, approximately 34% (no effect: 29%; negative: 5%) reported no discernible positive effect on biomass or yield, 37% (no effect: 16%; negative: 21%) on fruit or leaf quality, and 60% (no effect: 47%; negative: 13%) on nutrient levels within plant tissues. To improve the performance of AMF in hydroponic systems, the meta-analysis recommended maintaining phosphorus levels in the nutrient solution within the range of 0.15 to 15.5 mg L−1 as elevated levels (40–75 mg L−1) were found to significantly reduce AMF colonization. Additionally, it was observed that certain hydroponic techniques, such as the presence of air bubbles generated by air pumps in floating hydroponic systems (Deep Flow technique) and continuous circulation of the nutrient solution (Ebb and Flow systems), may create dynamic conditions that could potentially hinder the introduction of AMF spores into hydroponic systems and potentially compromise the integrity of the spores and hyphae. [ABSTRACT FROM AUTHOR]

Summary: Most plants form root hyphal relationships with mycorrhizal fungi, especially arbuscular mycorrhizal fungi (AMF). These associations are known to positively impact plant biomass and competitive ability. However, less is known about how mycorrhizas impact other ecological interactions, such as those mediated by pollinators.We performed a meta‐regression of studies that manipulated AMF and measured traits related to pollination, including floral display size, rewards, visitation, and reproduction, extracting 63 studies with 423 effects.On average, the presence of mycorrhizas was associated with positive effects on floral traits. Specifically, we found impacts of AMF on floral display size, pollinator visitation and reproduction, and a positive but nonsignificant impact on rewards. Studies manipulating mycorrhizas with fungicide tended to report contrasting results, possibly because fungicide destroys both beneficial and pathogenic microbes.Our study highlights the potential for relationships with mycorrhizal fungi to play an important, yet underrecognized role in plant–pollinator interactions. With heightened awareness of the need for a more sustainable agricultural industry, mycorrhizal fungi may offer the opportunity to reduce reliance on inorganic fertilizers. At the same time, fungicides are now ubiquitous in agricultural systems. Our study demonstrates indirect ways in which plant‐belowground fungal partnerships could manifest in plant–pollinator interactions. [ABSTRACT FROM AUTHOR]

Toona ciliata var. pubescens, known as "Chinese mahogany", has high commercial value and is classified as a level II priority protected wild plant in China. However, due to overexploitation and its poor natural regeneration capacity, natural T. ciliata var. pubescens forests show varying degrees of decline in habitat adaptability. Arbuscular mycorrhizal fungi (AMF) symbiosis presents a potential strategy to enhance its regeneration. In this study, T. ciliata var. pubescens seedlings were inoculated with Septoglomus viscosum, followed by RNA-Seq analysis to compare gene expression differences between AMF-inoculated (AMI) and non-mycorrhizal (NM) treatments three months post-inoculation. A total of 16,163 differentially expressed genes (DEGs) were upregulated by AMF colonization, constituting 96.46% of the total DEGs. Specifically, 14,420 DEGs were exclusively expressed in the AMI treatment, while 35 DEGs were completely silenced. Most of the upregulated DEGs were located on the cell membrane, nucleus, and cytoskeleton and functioned in protein binding, S-adenosylmethionine-dependent methyltransferase activity, and lipid binding during cellular/macromolecule/protein localization, intracellular/protein transport, the cell cycle, and signal transduction. Additionally, lots of key genes related to oxidative stress responses, nutrient transport, and small GTPase-mediated signal transduction were found to be upregulated. These results suggest that AMF inoculation may enhance root cell growth by activating genes involved in nutrient uptake, stress responses, signal transduction, and substance transportation. This study elucidates the molecular mechanisms underlying the growth promotion of T. ciliata var. pubescens through AMF symbiosis, laying a foundation for the future application of AMF in its natural forest regeneration. [ABSTRACT FROM AUTHOR]

At the southeastern periphery of the Tibetan Plateau, the subalpine ecosystem hosts grasses as some of the most substantial species. However, the community and function of arbuscular mycorrhizal fungi (AMF) around the rhizospheres of grasses in the subalpine zone are still poorly understood. In the present study, 28 soils and 11 species of dominant grasses collected from four microhabitats (shrubland, grassland, woodland, and forest) in the subalpine zone of northwestern Yunnan, China, were used to investigate the AMF community by Illumina MiSeq high-throughput sequencing technology as well as nutrient contents. Among the four microhabitats, the maximum soil nutrient levels around the rhizospheres of grasses were observed in woodland. The nitrogen, phosphorus, and potassium concentrations in Dactylis glomerata shoots were significantly higher than those in the other 10 grass species. The AMF diversity of grassland in summer was substantially greater than that of the other three microhabitats (p < 0.05). Discrepancies were observed within a given plant species across microhabitats; for example, in summer, the nitrogen concentration in the shoot of Iris tectorum in woodland was significantly higher than that in both forest and shrubland (p < 0.05). A total of eight genera were detected in the AMF communities, which were dominated by Glomus, with a relative abundance of 45.4%–94.4% in summer and 60.5%–84.3% in winter. Moreover, the abundance of Glomus was significantly positively correlated with the content of alkali-hydrolyzable nitrogen in soil and nitrogen in grasses according to the Mantel test. As a critical nutrient element in soil, nitrogen is beneficial for plant growth. Thus, these results provide a better understanding of the resilience of soil AMF community and the ecological adaptability of grasses in the subalpine ecosystems of northwestern Yunnan. [ABSTRACT FROM AUTHOR]

The invasive plant Wedelia trilobata benefits in various aspects, such as nutrient absorption and environmental adaptability, by establishing a close symbiotic relationship with arbuscular mycorrhizal fungi (AMF). However, our understanding of whether AMF can benefit W. trilobata by influencing its metabolic profile remains limited. In this study, Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was conducted to analyze the metabolites of W. trilobata under AMF inoculation. Metabolomic analysis identified 119 differentially expressed metabolites (DEMs) between the groups inoculated with AMF and those not inoculated with AMF. Compared to plants with no AMF inoculation, plants inoculated with AMF showed upregulation in the relative expression of 69 metabolites and downregulation in the relative expression of 50 metabolites. AMF significantly increased levels of various primary and secondary metabolites in plants, including amino acids, organic acids, plant hormones, flavonoids, and others, with amino acids being the most abundant among the identified substances. The identified DEMs mapped 53 metabolic pathways, with 7 pathways strongly influenced by AMF, particularly the phenylalanine metabolism pathway. Moreover, we also observed a high colonization level of AMF in the roots of W. trilobata, significantly promoting the shoot growth of this plant. These changes in metabolites and metabolic pathways significantly affect multiple physiological and biochemical processes in plants, such as free radical scavenging, osmotic regulation, cell structure stability, and material synthesis. In summary, AMF reprogrammed the metabolic pathways of W. trilobata, leading to changes in both primary and secondary metabolomes, thereby benefiting the growth of W. trilobata and enhancing its ability to respond to various biotic and abiotic stressors. These findings elucidate the molecular regulatory role of AMF in the invasive plant W. trilobata and provide new insights into the study of its competitive and stress resistance mechanisms. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) and rhizobium play a significant role in plant symbiosis. However, their influence on the rhizosphere soil microbiome associated with nutrient acquisition and soil health is not well defined in the drylands of Montana (MT), USA. This study investigated the effect of microbial inoculants as seed treatment on pea yield, nutrient uptake, potential microbial functions, and rhizosphere soil microbial communities using high-throughput sequencing of 16S and ITS rRNA genes. The experiment was conducted under two contrasting dryland conditions with four treatments: control, single inoculation with AMF or Rhizobium, and dual inoculations of AMF and Rhizobium (AMF+Rhizobium). Our findings revealed that microbial inoculation efficacy was site-specific. AMF+Rhizobium synergistically increased grain yield at Sidney dryland field site (DFS) 2, while at Froid site, DFS 1, AMF improved plant resilience to acidic soil but contributed a marginal yield under non-nutrient limiting conditions. Across dryland sites, the plants' microbial dependency on AMF+Rhizobium (12%) was higher than single inoculations of AMF (8%) or Rhizobium (4%) alone. Variations in microbial community structure and composition indicate a site-specific response to AMF and AMF+Rhizobium inoculants. Overall, site-specific factors significantly influenced plant nutrient uptake, microbial community dynamics, and functional potential. It underscores the need for tailored management strategies that consider site-specific characteristics to optimize benefits from microbial inoculation. [ABSTRACT FROM AUTHOR]

Panax notoginseng is a highly valued perennial medicinal herb plant in Yunnan Province, China, and the taproots are the main medicinal parts that are rich in active substances of P. notoginseng saponins. The main purpose of this study is to uncover the physiological and molecular mechanism of Panax notoginseng saponin accumulation triggered by methyl jasmonate (MeJA) under arbuscular mycorrhizal fungi (AMF) by determining physiological indices, high-throughput sequencing and correlation analysis. Physiological results showed that the biomass and saponin contents of P. notoginseng, the concentrations of jasmonic acids (JAs) and the key enzyme activities involved in notoginsenoside biosynthesis significantly increased under AMF or MeJA, but the interactive treatment of AMF and MeJA weakened the effect of AMF, suggesting that a high concentration of endogenous JA have inhibitory effect. Transcriptome sequencing results indicated that differential expressed genes (DEGs) involved in notoginsenoside and JA biosynthesis were significantly enriched in response to AMF induction, e.g., upregulated genes of diphosphocytidyl-2-C-methyl-derythritol kinases (ISPEs), cytochrome P450 monooxygenases (CYP450s)_and glycosyltransferases (GTs), while treatments AMF-MeJA and salicylhydroxamic acid (SHAM) decreased the abundance of these DEGs. Interestingly, a high correlation presented between any two of saponin contents, key enzyme activities and expression levels of DEGs. Taken together, the inoculation of AMF can improve the growth and saponin accumulation of P. notoginseng by strengthening the activities of key enzymes and the expression levels of encoding genes, in which the JA regulatory pathway is a key link. This study provides references for implementing ecological planting of P. notoginseng, improving saponin accumulation and illustrating the biosynthesis mechanism. [ABSTRACT FROM AUTHOR]

Biostimulants and bioinoculants offer the potential to enhance nutrient use efficiency within agricultural cropping systems and thus reduce the amount of mineral fertilizers needed to support crop growth. Considerable uncertainty, however, exists about their efficacy under different management regimes. The present field-based study investigated the effects of phosphorus (P) solubilizing bacteria (PSB) and mycorrhizal (AMF) inoculants in the presence of a range of mineral-based P fertilizers, including triple superphosphate (TSP), struvite and rock phosphate (RP), on the growth, yield, and P uptake of barley (Hordeum vulgare L.). Two consecutive field experiments performed in a low P soil (Eutric Cambisol) revealed that the bioinoculants (PSB and AMF) promoted plant P uptake and grain yield. Moreover, in comparison to P fertilizers lacking bio-inoculants, the application of external P sources combined with bio-inoculants led to significant increases in leaf P concentration, total P uptake, plant dry matter, grain P concentration, and crop yield. Grain yield significantly correlated with P uptake by roots and above-ground parts (i.e. stems, leaves, and spikes) as well as grain P concentration in both seasons. It is concluded that bioinoculants can help improve sustainable P use ultimately leading to greater sustainability of cropping systems and resilience in soil P cycling. [ABSTRACT FROM AUTHOR]

Abstract Arbuscular mycorrhizal fungi (AMF) are widespread obligate symbionts of plants. This dynamic symbiosis plays a large role in successful plant performance, given that AMF help to ameliorate plant responses to abiotic and biotic stressors. Although the importance of this symbiosis is clear, less is known about what may be driving this symbiosis, the plant's need for nutrients or the excess of plant photosynthate being transferred to the AMF, information critical to assess the functionality of this relationship. Characterizing the AMF community along a natural plant productivity gradient is a first step in understanding how this symbiosis may vary across the landscape. We surveyed the AMF community diversity at 12 sites along a plant productivity gradient driven by soil nitrogen availability. We found that AMF diversity in soil environmental DNA significantly increased along with the growth of the host plants Acer rubrum and A. saccharum., a widespread tree genus. These increases also coincided with a natural soil inorganic N availability gradient. We hypothesize photosynthate from the increased tree growth is being allocated to the belowground AMF community, leading to an increase in diversity. These findings contribute to understanding this complex symbiosis through the lens of AMF turnover and suggest that a more diverse AMF community is associated with increased host–plant performance.

Mycorrhizae are found on about 70–80 % of the roots of all plant species; ectomycorrhizae (ECM) are mostly found on woody plants and gymnosperms, whereas arbuscular mycorrhizal fungi (AMF) are found on 80–90 % of all plant species. In abandoned mining sites, woody plants dominate, while non-woody species remain scarce. However, this pattern depends on the specific mine site and its ecological context. This review article explores the potential of using mycorrhizae-plant associations to enhance and facilitate the remediation of mine wastelands and metal-polluted sites. In this review, we employed reputable databases to collect articles and relevant information on mycorrhizae and their role in plant growth and soil fertility spanning from the 1990s up to 2024. Our review found that the abilities of plants selected for minewasteland reclamation can be harnessed effectively if their mycorrhizae utilization is known and considered. Our findings indicate that AMF facilitates plant cohabitation by influencing species richness, feedback effects, shared mycelial networks, and plant-AMF specificity. Several types of mycorrhizae have been isolated from mine wastelands, including Glomus mosseae, which reduces heavy metal accumulation in plants, and Rhizophagus irregularis, which enhances plant growth and survival in revegetated mine sites. Additionally, studies on ECM in surface mine spoil restoration stands highlight their role in enhancing fungal biodiversity and providing habitats for rare and specialized fungal species. Recent research shows that ECM and AMF fungi can interact synergistically to enhance plant growth, with ECM improving plant nitrogen absorption and AMF increasing nitrogen use efficiency. Our review also found that despite their critical role in improving plant growth and resilience, there remains limited knowledge about the specific mechanisms by which mycorrhizae communicate with each other and other microorganisms, such as bacteria, root-associated fungi, soil protozoa, actinomycetes, nematodes, and endophytes, within the soil matrix. This article highlights the connection between mycorrhizae and plants and other microorganisms in mine wastelands, their role in improving soil structure and nutrient cycling, and how mycorrhizae can help restore soil fertility and promote plant growth, thus improving the overall environmental quality of mine wasteland sites.

Twisted disease is one of the problems in shallot cultivation. The application of the biological agents Bacillus velezensis and Arbuscular Mycorrhizal Fungi is an alternative expected to overcome disease problems in shallot plantings. The purpose of this study was to determine the effect of the application of B. velezensis and Arbuscular Mycorrhizal Fungi on the growth and health of shallot. The research was conducted in Gotakan, Panjatan, Kulon Progo, and the Phytopathology Laboratory, Department of Plant Protection, Faculty of Agriculture, Universitas Gadjah Mada, Yogyakarta. Shallot treatments with the application of biological agents were carried out either individually by soaking the bulbs in B. velezensis suspension before planting, coating the bulbs using Arbuscular Mycorrhizal Fungus (Rhizophagus intraradices) with a carrier medium of kaolin flour before planting, and a combination of spraying the B. velezensis suspension on plants at two-week intervals during the growth period and coating the bulbs before planting with R. intraradices. The results of the study showed that the shallot-applied single application of B. velezensis reduced the intensity and incidence of twisted disease by 2.51% and 37.6%, respectively. The combination treatment of B. velezensis and R. intraradices was able to increase the resistance of bulbs to postharvest pathogen Fusarium solani infection, with infected bulbs and areas of 0.70% and 0.71%, respectively.

Soil salinization, especially in arid and semi-arid regions, is one of the major abiotic stresses that affect plant growth. To mediate and boost plant tolerance against this abiotic stress, arbuscular mycorrhizal fungi (AMF) symbiosis is commonly thought to be an effective tool. So, the main purpose of this study was to estimate the role of AMF (applied as a consortium of Claroideoglomus etunicatum, Funneliformis mosseae, Rhizophagus fasciculatum, and R. intraradices species) symbiosis in mitigating deleterious salt stress effects on the growth parameters (shoot length (SL), root length (RL), shoot dry weight (SDW), root dry weight (RDW), root surface area (RSA), total root length (TRL), root volume (RV), root diameter (RD), number of nodes and leaves) of Cenchrus ciliaris L. plants through improved accumulations of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll), proline and phenolic compounds. The results of this experiment revealed that the roots of C. ciliaris plants were colonized by AMF under all the applied salinity levels (0, 75, 150, 225, and 300 mM NaCl). However, the rate of colonization was negatively affected by increasing salinity as depicted by the varied colonization structures (mycelium, vesicles, arbuscules and spores) which were highest under non-saline conditions. This association of AMF induced an increase in the growth parameters of the plant which were reduced by salinity stress. The improved shoot/root indices are likely due to enhanced photosynthetic activities as the AMF-treated plants showed increased accumulation of pigments (chlorophyll a, chlorophyll b and total chlorophyll), under saline as well as non-saline conditions, compared to non-AMF (N-AMF) plants. Furthermore, the AMF-treated plants also exhibited enhanced accumulation of proline and phenolic compounds. These accumulated metabolites act as protective measures under salinity stress, hence explaining the improved photosynthetic and growth parameters of the plants. These results suggest that AMF could be a good tool for the restoration of salt-affected habitats. However, more research is needed to check the true efficacy of different AMF inoculants under field conditions.

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha−1, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha−1) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production.

Arbuscular mycorrhizal fungi (AMF) can penetrate plant root cortical cells, establish a symbiosis with most land plant species, and form branched structures (known as arbuscules) for nutrient exchange. Plants have evolved a complete plant-AMF symbiosis system to sustain their growth and development under various types of abiotic stress. Here, we highlight recent studies of AM symbiosis and the regulation of symbiosis process. The roles of mycorrhizal symbiosis and host plant interactions in enhancing drought resistance, increasing mineral nutrient uptake, regulating hormone synthesis, improving salt resistance, and alleviating heavy metal stress were also discussed. Overall, studies of AM symbiosis and a variety of abiotic stresses will aid applications of AMF in sustainable agriculture and can improve plant production and environmental safety. [ABSTRACT FROM AUTHOR]

Drought is a major threat to food security worldwide. Recently, the root–soil interface has emerged as a major site of hydraulic resistance during water stress. Here, we review the impact of soil drying on whole-plant hydraulics and discuss mechanisms by which plants can adapt by modifying the properties of the rhizosphere either directly or through interactions with the soil microbiome. [ABSTRACT FROM AUTHOR]

Food security requires intensive and high agricultural inputs which are unsustainable given their impacts on plant-associated microbiome, especially the arbuscular mycorrhizal fungi (AMF). The significance of AMF in ecosystems and their positive effects on plants are indisputable and they were well studied and discussed, but the importance of AMF diversity and abundance for plants are less tenable. On the other hand, the variability in AMF diversity and abundance due to some agricultural practices may have different impacts on plants, and could affect plant growth and productivity. Therefore, understanding the impacts of the agricultural management practices on AMF diversity and abundance as well as roots colonization would help researchers and agronomic scientific community to develop approaches ensuring the establishment of a good symbiosis and could contribute to the identification and the success of sustainable management options. In this review, we discussed the importance of diversity, abundance and infectivity of AMF for plants and the effect of four agricultural management practices namely the inoculation of plants with AMF, the cropping systems, the fertilization, and the tillage on AMF diversity and abundance in relation with the crops' productivity. [ABSTRACT FROM AUTHOR]

Recent agricultural research has prioritized the development of environmentally friendly management strategies to ensure food security, among which the application of biostimulants such as brown algae extracts, arbuscular mycorrhizal fungi (AMF), and their combination are included. The experimental protocol was based on the factorial combination of two planting times (4 May and 1 June) and seven biostimulant treatments (three brown algae species, Cystoseria tamariscifolia—C.t.; Fucus vesiculosus—F.v.; Padina pavonica—P.p.; arbuscular mycorrhizal fungi—AMF; C.t. + AMF; F.v. + AMF; P.p. + AMF) plus an untreated control. The earlier transplant resulted in a higher yield, due to the higher number of fruits per plant, and a higher plant fresh and dry biomass. The treatments with P.p. and F.v. extracts and the combination P.p. + AMF led to the highest yields (56.7 t ha−1), mainly due to the highest fruit number per plant. The earlier planting time led to higher values of dry residue, soluble solids, firmness, and colour component ‘a’. The highest values of fruit dry residue were recorded under the F.v. and P.p. extracts, and the combinations F.v. + AMF and P.p. + AMF, the highest soluble solid content with P.p. treatment, and firmness under P.p. + AMF. The highest levels of ‘L’ and ‘a’ fruit colour components were obtained under the P.p. extract treatment, of ‘b’ upon the application of P.p. and F.v. extract, and AMF + P.p. and AMF + F.v. The later planting time led to significantly higher values of the antioxidant parameters, as did the application of the P.p. extract and P.p. + AMF. CAT activity was more intense corresponding to the later tomato crop cycle, P.p. extract, and AMF + P.p. Overall, our study highlights the potential of biostimulants, particularly brown algae extracts and their combination with AMF, to improve tomato yield, antioxidant properties, and biochemical activities.

Panax notoginseng is a highly valued perennial medicinal herb in China and is widely used in clinical treatments. The main purpose of this study was to elucidate the changes in the composition of P. notoginseng saponins (PNSs), which are the main bioactive substances, triggered by arbuscular mycorrhizal fungi (AMF) via ultrahigh-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (UPLC–ESI–MS/MS). A total of 202 putative terpenoid metabolites were detected, of which 150 triterpene glycosides were identified, accounting for 74.26% of the total. Correlation analysis, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS–DA) of the metabolites revealed that the samples treated with AMF (group Ce) could be clearly separated from the CK samples. In total, 49 differential terpene metabolites were identified between the Ce and CK groups, of which 38 and 11 metabolites were upregulated and downregulated, respectively, and most of the upregulated differentially abundant metabolites were mainly triterpene glycosides. The relative abundances of the two major notoginsenosides (MNs), ginsenosides Rd and Re, and 13 rare notoginsenosides (RNs), significantly increased. The differential saponins, especially RNs, were more easily clustered into one branch and had a high positive correlation. It could be concluded that the biosynthesis and accumulation of some RNs share the same pathways as those triggered by AMF. This study provides a new way to obtain more notoginsenoside resources, particularly RNs, and sheds new light on the scientization and rationalization of the use of AMF agents in the ecological planting of medicinal plants.

Symbiotic microorganisms such as arbuscular mycorrhizal fungi (AMF) and rhizobia (Rh) both promote host plant N acquisition, but whether and how the combination affects host plant nitrogen (N) assimilation remains unclear. To clarify the role of AMF and rhizobia on N assimilation in white clover (Trifolium repens), the effect of single or combined inoculation with an arbuscular mycorrhizal fungus Paraglomus occultum and a rhizobium Rhizobium trifolii on plant growth, photosynthesis, leaf N and amino acid contents, and the activities of N assimilation-related enzymes were analyzed in white clover under potted conditions. The results obtained were as follows: (1) The plant height, stolon length, leaf number, shoot biomass, total biomass, chlorophyll b and total chlorophyll contents, steady-state light quantum efficiency, and leaf N contents of white clover were significantly increased by single inoculation with Paraglomus occultum, single Rhizobium trifolii, and combined inoculations of Paraglomus occultum and Rhizobium trifolii, along with the order of combined inoculations of Paraglomus occultum and Rhizobium trifolii > single Paraglomus occultum > single Rhizobium trifolii > non-inoculation control. (2) Combined inoculations of Paraglomus occultum and Rhizobium trifolii significantly increased the contents of various amino acids including alanine, arginine, asparagine, aspartate, glutamine, glutamic acid and histidine in leaves of white clover, and distinctly improved the activities of nitroreductase, nitrite reductase, glutamine synthetase, glutamate synthetase, glutamate dehydrogenase, asparagine synthetase, and aspartate aminotransferase. In addition, the introduction of Rhizobium trifolii significantly promoted the colonization of Paraglomus occultum to roots of white clover, suggesting the partnership between the two. Therefore, it is concluded that combined inoculations of AMF and rhizobia promote N assimilation, generate more amino acids, and further promote the growth of white clover by activating the activities of N assimilation-related enzymes. It is further demonstrated that AMF and rhizobia have synergistic effects on promoting N assimilation of white clover.