Search Results (312)

Arbuscular mycorrhizal fungi (AMF) form symbiotic interactions with most terrestrial plants, enhancing nutrient uptake and stress resilience. Organic amendments like biochar, compost, and manure are advocated to improve soil health and promote AMF symbiosis. However, empirical evidence of their effects on root AMF colonization is inconsistent, and a systematic understanding of the governing factors is lacking. Here, we synthesized the responses of root AMF colonization in agricultural systems to biochar, compost, and manure input from 85 studies (663 pairs of observations) globally based on a meta-analysis. Overall, biochar and compost/manure significantly increased root AMF colonization. However, these effects were highly context-dependent. Biochar most strongly promoted colonization in coarse-textured soils with low total potassium (TK ≤ 25 g kg⁻¹) and high total carbon (TC ≥ 11 g kg⁻¹), particularly for fruit and tuber crops. In contrast, compost/manure were most effective in fine-textured soils with high TK (≥25 g kg⁻¹) and low bulk density (BD ≤ 1.3 g cm⁻³). Notably, compost/manure suppressed colonization in neutral pH (6.5 < pH < 7.5) and high BD soils (>1.3 g cm⁻³). Key amendment properties drove these responses: biochar with low electrical conductivity (EC < 5 dS m⁻¹), high sodium and low macronutrient content was most beneficial, whereas compost/manure with high total nitrogen (TN > 9 g kg⁻¹) and low organic carbon (OC ≤ 500 g kg⁻¹) performed best. The efficacy of organic amendments in enhancing AMF symbiosis is not universal but dictated by a complex interplay of soil properties and amendment characteristics. Our findings provide a robust, quantitative framework for tailoring amendment strategies to specific agro-ecological contexts, enabling farmers and land managers to selectively use biochar or compost/manure to harness AMF benefits for sustainable crop production. Full article

Ramaria flavobrunnescens is an ectomycorrhizal coral mushroom that is often found growing in eucalyptus forests. The mushroom has been linked to accidental ingestion-associated livestock poisonings in South America, though the toxicological agent has not yet been described. Mushroom samples identified as R. flavobrunnescens were analyzed by liquid chromatography high-resolution mass spectrometry (LC–MS/MS) to determine the potential source of the toxicity, and to provide a metabolomic profile of the species. Previously reported Ramaria secondary metabolites were detected, including ramarins, ramariolides, pistillarin and arsenic-containing compounds. A number of bacterial species were isolated from R. flavobrunnescens that produced iron-chelating cyclic peptides, which were detected in the mushroom samples. Interestingly, we detected a series of eucalyptus tree secondary metabolites in abundance from R. flavobrunnescens fruiting bodies, some of which have reported toxicities and bioactivities. To our knowledge, this is the first report of eucalyptus secondary metabolites in a mushroom. The diversity of secondary metabolites identified in the mushroom extracts provides insight into the potential complex ecological interactions between R. flavobrunnescens, its associated microbiota, and its mycorrhizal interaction with eucalyptus trees. Full article

Cadmium (Cd) drastically inhibits plant growth and metabolism, whereas arbuscular mycorrhizal (AM) fungi can enhance plant Cd tolerance through metabolic regulation. To clarify tissue-specific responses, we conducted a pot experiment combined with GC-MS to examine how AM fungi influence root and leaf metabolism of ryegrass (Lolium perenne L.) under different Cd levels. Root and leaf metabolomes diverged substantially in composition and function. In total, 83 metabolites were identified in roots, mainly phenolics, amines, and sugars associated with carbon–nitrogen metabolism and stress-defense pathways, whereas 75 metabolites were identified in leaves, largely related to photosynthetic metabolism. Roots were more sensitive to Cd, showing significant metabolic alterations at Cd ≥ 5 mg·kg⁻¹, including disruption of galactose metabolism, while leaves exhibited notable changes only at Cd ≥ 100 mg·kg⁻¹, with suppression of citrate, L-aspartate, and starch and sucrose metabolism. AM fungi modulated plant metabolism more strongly under Cd stress. Specifically, AM fungi restored Cd-suppressed galactose and glyoxylate/dicarboxylate metabolism in roots, enhanced starch and sucrose metabolism and amino acid pathways in leaves, and increased stress-related amino acids and organic acids in both tissues. Overall, AM fungi substantially alleviated Cd-induced metabolic inhibition, particularly at Cd ≥ 50 mg·kg⁻¹, providing mechanistic insight into AM-enhanced Cd tolerance and supporting the application of AM symbiosis in remediation of Cd-contaminated soils. Full article

Orchid seed germination requires symbiotic association with mycorrhizal fungi that provide essential nutrients for germination and subsequent growth. Extensive research has elucidated the pivotal role of the mycorrhizal fungus Tulasnella sp. in the modulation of seed germination and growth processes in Bletilla striata (Thunb.) Reiehb.f. However, the molecular mechanisms underlying this symbiosis remain poorly characterized. Our integrated transcriptomic-metabolomic analysis of symbiotic germination revealed that co-cultivation of Tulasnella sp. bj1 with B. striata seeds significantly downregulates the expression of plant-derived flavonoid biosynthetic genes, with flavonoid degradation potentially alleviating germination and growth inhibition. The bj1 strain modulates indoleacetic acid (IAA) biosynthesis in B. striata by upregulating the expression of plant-derived tryptophan decarboxylase (TDC) in the tryptophan pathway and hydrolytic enzymes (NtAMI) in the indoleacetamide pathway, with elevated IAA potentially contributing to seed germination and growth. Moreover, bj1 suppresses the jasmonic acid (JA) biosynthetic pathway of B. striata by downregulating key plant-derived biosynthetic genes, concurrently promoting the accumulation of 12-hydroxyjasmonic acid—a metabolite associated with plant immune regulation that may favor colonization and symbiotic establishment with B. striata seeds. Additionally, bj1 induces the expression of polysaccharide-degrading enzymes, potentially improving carbon source utilization to support protocorm development. In conclusion, bj1 modulates the immune response of B. striata seeds, facilitating the establishment of a symbiotic relationship. Subsequently, the germination and growth of B. striata seeds are enhanced through reduced flavonoid accumulation, increased IAA synthesis, and improved carbon source utilization. Consequently, this investigation provides a crucial foundation for elucidating mechanisms governing symbiotic germination in B. striata. Full article

To elucidate the potential of integrated multi-omics approaches for studying systemic mechanisms of mycorrhizal fungi in mediating plant-microbe interactions, this study employed the Tuber-inoculated Corylus system as a model to demonstrate how high-throughput profiling can investigate how fungal inoculation reshapes the rhizosphere microbial community and correlates with host metabolism. A pot experiment was conducted comparing inoculated (CTG) and non-inoculated (CK) plants, followed by integrated multi-omics analysis involving high-throughput sequencing (16S/ITS), functional prediction (PICRUSt2/FUNGuild), and metabolomics (UPLC-MS/MS). The results demonstrated that inoculation significantly restructured the fungal community, establishing Tuber as a dominant symbiotic guild and effectively suppressing pathogenic fungi. Although bacterial alpha diversity remained stable, the functional profile shifted markedly toward symbiotic support, including antibiotic biosynthesis and environmental adaptation. Concurrently, root metabolic reprogramming occurred, characterized by upregulation of strigolactones and downregulation of gibberellin A5, suggesting a potential “symbiosis-priority” strategy wherein carbon allocation shifted from structural growth to energy storage, and plant defense transitioned from broad-spectrum resistance to targeted regulation. Multi-omics correlation analysis further revealed notable associations between microbial communities and root metabolites, proposing a model in which Tuber acts as a core regulator that collaborates with the host to assemble a complementary micro-ecosystem. In summary, the integrated approach successfully captured multi-level changes, suggesting that Tuber-Corylus symbiosis constitutes a fungus-driven process that transforms the rhizosphere from a competitive state into a mutualistic state, thereby illustrating the role of mycorrhizal fungi as “ecosystem engineers” and providing a methodological framework for green agriculture research. Full article

Agricultural systems in Mediterranean-type climates are increasingly threatened by drought, salinity, extreme temperatures, heavy metal contamination, and pathogen pressure, all of which undermine crop productivity and agroecosystem stability. In this context, arbuscular mycorrhizal fungi (AMF), natural symbionts of most terrestrial plants, emerge as key biological agents capable of enhancing crop resilience. Following PRISMA guidelines, this systematic review synthesizes current knowledge on the role of AMF in mitigating abiotic and biotic stresses, highlighting their potential as a central component of sustainable Mediterranean agriculture. The available evidence demonstrates that AMF symbiosis significantly increases plant tolerance to multiple stressors across major crop families, including Poaceae, Fabaceae, Solanaceae, and Asteraceae. Under abiotic constraints, AMF improve water and nutrient uptake via extensive hyphal networks, modulate ion homeostasis under salinity, enhance tolerance to thermal extremes, and reduce heavy metal toxicity by immobilizing contaminants. Regarding biotic stresses, AMF induce systemic resistance to pathogens, stimulate secondary metabolite production that deters herbivores, and suppress parasitic nematode populations. Moreover, co-inoculation with other biostimulants, such as plant growth-promoting rhizobacteria, shows synergistic benefits, further improving crop productivity and resource-use efficiency. Overall, AMF represent an effective and multifunctional nature-based tool for improving the sustainability of Mediterranean agroecosystems. However, further research is required to evaluate AMF performance under simultaneous multiple stress factors, thereby reflecting real-world conditions and enabling a more integrated understanding of their agronomic potential. Full article

The interplay between phosphate (Pi) signaling and defense pathways is crucial for plant fitness, yet its molecular basis, particularly in wheat, remains poorly understood. Here, we functionally characterized the plasma membrane-localized high-affinity phosphate transporter TaPT3-2D and demonstrated its essential roles in Pi uptake, arbuscular mycorrhizal (AM) symbiosis, and fungal disease resistance. Quantitative analyses showed that TaPT3-2D expression was strongly induced by AM colonization (165-fold increase) and by infection with Bipolaris sorokiniana (54-fold increase) and Gaeumannomyces tritici (15-fold increase). In contrast, virus-induced gene silencing (VIGS) of TaPT3-2D reduced Pi uptake and mycorrhizal colonization. Moreover, TaPT3-2D-silenced plants exhibited increased susceptibility to biotrophic, hemibiotrophic, and necrotrophic fungi, accompanied by reduced expression of pathogen-related genes. The simultaneous impairment of Pi uptake, AM symbiosis, and defense responses in silenced plants indicates that TaPT3-2D functionally couples these processes. Functional complementation assays in low-Pi medium further revealed that TaPT3-2D partially rescued defective Pi uptake in mutant MB192 yeast, supporting its role as a high-affinity phosphate transporter. Collectively, these results identify TaPT3-2D as both a key regulator of individual pathways and as a molecular link connecting Pi homeostasis, symbiotic signaling, and disease resistance in wheat. Full article

Agroecology is increasingly shaped by the convergence of traditional knowledge, farmers’ lived experiences, and scientific research, fostering a plural dialog that embraces the ecological and socio-political complexity of agricultural systems. Within this framework, soil biodiversity is essential for maintaining ecosystem functions, with soil microbiology, and particularly arbuscular mycorrhizal fungi (AMF), playing a pivotal role in enhancing soil fertility, plant health, and agroecosystem resilience. This review explores the synergy between agroecological practices and AMF by examining their ecological, economic, epistemic, and territorial contributions to sustainable agriculture. Drawing on recent scientific findings and Latin American case studies, it highlights how practices such as reduced tillage, crop diversification, and organic matter inputs foster diverse and functional AMF communities and differentially affect their composition and ecological roles. Beyond their biological efficacy, AMF are framed as relational and socio-ecological agents—integral to networks that connect soil regeneration, food quality, local autonomy, and multi-species care. By bridging ecological science with political ecology and justice in science-based knowledge, this review offers a transdisciplinary lens on AMF and proposes pathways for agroecological transitions rooted in biodiversity, cognitive justice, and territorial sustainability. Full article

Valued above all others, the white truffle species (Tuber magnatum Picco) is highly dependent on the forest ecosystem and its underground biology. Despite its economic importance, knowledge of its biology and mycorrhizal symbioses remains limited; moreover, natural yields have sharply declined, and cultivation efforts have produced inconsistent results. This study evaluated various forest and mycorrhizal inoculation techniques to promote T. magnatum mycelium development in three Tuscan sites converted to truffle cultivation, using qPCR analysis. Alongside conventional practices like irrigation, mulching, and tillage, an experimental method with a sterile, spore-inoculated soil barrier was tested to improve host root establishment, enhance mycorrhization, and maintain long-term symbiosis for healthy truffle ecosystems. Soil analyses nine months after planting Quercus robur L. seedlings showed significant differences in Tuber magnatum mycelium abundance across sites and treatments. The MA treatment—mycorrhized seedlings combined with a sterile, inoculated substrate and separation diaphragm—produced the highest mycelial levels, underscoring the importance of initial mycorrhization and soil manipulation. These findings provide valuable insights for optimizing forest management and improving truffle cultivation by enhancing mycelial development, a key step toward increasing truffle production. Full article

Most land plants engage in a mutualistic interaction with arbuscular mycorrhizal fungi (AMF), for which Rhizophagus irregularis is a model species. Like plant pathogenic fungi, AMF genomes encode hundreds of putative effector proteins. However, for only a few, the molecular mechanisms by which they alter the host’s physiology are known. Here, we combined several reverse genetic approaches to unravel the role of the RIRG190 effector protein in arbuscular mycorrhiza (AM) symbiosis. Using multiple heterologous tools, evidence is provided that the RIRG190 effector is secreted and localizes to the plant nucleus. Moreover, by means of yeast two-hybrid (Y2H) and ratiometric bimolecular fluorescence complementation (rBIFC) assays, the data demonstrate that RIRG190 interacts with the protein Something About Silencing (SAS10), known to be involved in rRNA biogenesis in the nucleolus of cortical cells. Our findings suggest that rRNA biogenesis is a key process modulated by AMF, potentially to enhance plant metabolic activity, facilitating cell cycle progression, and to support the establishment of the symbiosis. Full article

The use of mycorrhizal fungi to enhance orchid seed germination and seedling growth is a promising approach for orchid propagation and conservation, but practical applications remain limited. In this study, we developed a direct seeding technique based on mycorrhizal symbiosis using Dendrobium officinale. Seeds were inoculated with two fungal strains, Serendipita officinale (SO) and Serendipita indica (SI), individually or in combination, and cultivated on three substrates to identify optimal fungus–substrate combinations. SO achieved the highest germination rate (52.9 ± 5.6%) at 30 days on substrate 1 but declined at later stages, while SI performed best on substrate 3 at 30 days (72.3 ± 6.7%) but was less effective after 90 days. The SO and SI mixture showed strong synergistic effects on substrate 1, with peak germination (48.7 ± 5.9%) and seedling formation (45.6 ± 5.1%) at 120 days. Substrates 1 and 3 significantly outperformed 2 (p < 0.05), with 1 promoting rapid early germination and 3 favoring long-term seedling establishment. In contrast, controls without fungi showed less than 5% for all indices, confirming the necessity of symbiotic fungi. Microscopic observations revealed typical orchid mycorrhizal structures and dynamic hyphal turnover, providing histological evidence of the symbiotic mechanism. These findings establish a practical framework for mycorrhizal-assisted propagation and contribute to the ecological cultivation and conservation of D. officinale. Full article

Mycoforestry, a farming system that produces edible fungi crops in forest plantations through controlled mycorrhizal symbiosis, has the potential to enhance biodiversity in forestry plantations and mitigate some of the negative impacts associated with modern agriculture, such as soil erosion, habitat degradation, and carbon emissions. Mycoforestry systems typically exploit a range of native fungi that can be inoculated into planting stock of commercial tree species, with biodiversity benefits delivered through expanded habitat provision for the fungi and a range of other organisms through alterations to stand structure. One mycoforestry system showing strong potential for commercial viability involves the cultivation of Lactarius deliciosus (L.:Fr.) S.F. Gray in Pinaceae plantations. This review aims to evaluate the benefits of mycoforestry systems with a focus on Lactarius deliciosus (L.:Fr.) as a case study. It will review the state of the art and discuss technical developments necessary for the successful large-scale application of mycoforestry systems. Full article

Mixed cropping may positively affect soil fertility and soil biological activities, such as those related to mycorrhizal colonization intensity (M%), which plays a vital role in the plant nutrient cycle and can improve tolerance to drought and pathogens. This plant and soil fungi symbiosis helps to reduce dependency on chemical fertilizers, promotes sustainable agricultural practices, and minimizes environmental impacts. However, field studies that clearly assess the effects of cereal/legume intercropping on mycorrhizal intensity and relate it to plant productivity, yield quality, and plant adaptation to climate change are lacking. This field experiment was conducted to assess the effects of cereals/legume intercropping on mycorrhizal colonization, and to explore its interaction with physical cereal root parameters and crop yield. Three main crops, spring barley, oat, and field pea, were grown as monocultures. For the spring barley and oat, the study also included two different fertilization levels (with and without organic fertilizers) and legume intercropping (field pea and red clover). The intercropping had a significant impact on spring barley and oat root length, diameter, and specific root length. The general average of root length and diameter was higher in oat–pea and barley–pea cropping systems. The most significant effect in root architecture parameters observed in red clover was when it was intercropped with barley or oat. The establishment of field pea intercrop significantly increased M% in spring barley and had a positive effect on the grain yields of both spring barley and oat. Meanwhile, red clover intercropping enhanced M% and grain yield in oats but had no such effect in barley. In both spring barley and oat, M% was positively correlated with grain yield. Full article

Arbuscular mycorrhizal fungi (AMF) form symbiotic relationships with most crops. They function as promising sustainable agricultural amendments by synergizing with biochar to enhance plant nutrient uptake. However, the effects of AMF and biochar interactions on the yield and nutrient uptake of leguminous crops and the underlying mechanisms remain insufficiently understood. This study employed a two-factor experimental design. Under the baseline conditions of no fertilization (CK), chemical fertilizer application (CF), and biochar-based fertilizer application (BF), treatments with and without AMF inoculation were established, resulting in a total of six experimental treatments. Compared to BF treatment alone, the combined application of AMF and BF (AM + BF) synergistically increased soybean biomass (12.81%) and grain yield (19.45%). This synergistic effect was accompanied by increased plant nitrogen (14.04%) and potassium (21.82%) accumulation. Notably, despite the highest yield, the AM + BF treatment showed a 22.22% reduction in nodule formation rate. This reveals that plant nitrogen acquisition strategies have shifted from relying on biological nitrogen fixation to efficient mycorrhizal pathways, reflecting an inherent optimization of carbon economy. The PLS-SEM model revealed that AMF inoculation altered yield-driving mechanisms: in the absence of AMF, yield could be directly predicted by soil nutrient levels; however, this relationship was disrupted after AMF inoculation. The soil nutrient pathway became non-significant, indicating a transition from a soil chemistry-dependent model to a biologically driven one, where AMF–plant symbiosis became the primary regulator of nutrient uptake. These findings highlight that AMF-BF synergy creates a novel soil–plant feedback mechanism that enhances nutrient acquisition efficiency and optimizes carbon allocation, providing a sustainable approach to boost legume crop yields and reduce environmental footprints. Full article

We hypothesized that Tuber melanosporum colonization enhances growth and photosynthetic performance in Corylus avellana seedlings. Forty-eight seedlings were assessed for root colonization (stereomicroscopy, ITS sequencing) and photosynthetic traits (Li-6800F) under short-term disturbed and undisturbed rhizosphere conditions. Mycorrhizal colonization was found in 97.9% of seedlings (47/48). The mean colonization was 33.1% (SD = 16.1), 16.7% of seedlings showed more than 50% colonization per seedling, and 65.0% showed more than 30% colonization per seedling. Colonization declined with root depth and correlated with seedling length (r = 0.371, p = 0.01). In disturbed roots, longer root length predicted higher Gsw (r = 0.60), PhiCO₂ (r = 0.77), and PhiPSII (r = 0.70), while collar diameter negatively affected transpiration (r = −0.60). In undisturbed roots, collar-proximal colonization improved PhiPSII (r = 0.69, p = 0.02). Undisturbed seedlings showed ~2× higher CO₂ assimilation, stomatal conductance, quantum yield, and transpiration. These findings confirm that T. melanosporum enhances seedling physiology, especially under undisturbed conditions. Full article