Mycorrhiza最新文献

Arbuscular mycorrhizal fungi (AMF) lack the enzymatic capacity to directly mineralize many essential soil elements and therefore rely on their hyphosphere core microbiome, a microbial consortium increasingly recognized as the "second genome" of AMF. However, the definition, functional mechanisms, and ecological relevance of this core microbiome remain poorly resolved. This review addresses how hyphosphere core microorganisms regulate the mineralization of soil carbon, nitrogen, phosphorus, and sulfur. We first outline the conceptual development of the core microbiome and then, for the first time, propose a five-dimensional screening framework integrating abundance stability and universality, functional stability, dynamic responsiveness, ecological niche specificity, and community supportiveness to identify authentic core members. Using this framework, we synthesize evidence on the mechanisms by which the hyphosphere core microbiome mediates biomineralization, highlighting its role in converting organically bound nutrients into plant-available forms. By integrating the functions of hyphosphere core microorganisms across carbon, nitrogen, phosphorus, and sulfur cycles, this review provides a unified ecological perspective on how the AMF hyphosphere core microbiome drives soil nutrient turnover (Fig. 1). Overall, this framework advances understanding of hyphosphere ecology and offers practical implications for soil ecosystem restoration and sustainable agricultural management.

Invasive weeds often possess strong resistance to biotic stresses, which causes huge ecological problems. Both plant growth regulators (PGRs) and arbuscular mycorrhizal (AM) fungi contribute to plant growth and resistance. However, their combined interactions in invasive plants' defense remain poorly understood. To address this knowledge gap, the invasive weed Alternanthera philoxeroides was treated with gibberellins (GA) and paclobutrazol (PAC), inoculated with Clariodeoglous etunicatum to test its response to pathogenic fungi. We found that these two PGRs suppressed AM fungi colonization. Both GA and AM fungi significantly promoted aboveground plant growth, while the two PGRs and AM fungi reduced pathogen infection. Metabolite analysis revealed that AM fungi inoculation significantly elevated vanillic acid, gentisic acid, and pomiferin content. Moreover, flavone, organic acid, and amino acids were positively related with plant growth, while jasmonic acid and amino acids were correlated with plant resistance. Our findings provide direct evidence that, through PGRs and metabolites, AM fungi could be "chemical armed" and contribute to plant growth and resistance to pathogens. These findings offer new insights into how PGRs and AM fungi modulate metabolites to enhance invasive plants' resistance, which might contribute to understanding the mechanism of plant invasion and weed management in agro-ecosystem.

Climate change poses a major threat to ecosystems worldwide, including Iran's ecologically important Zagros oak forests. These forests are experiencing accelerating decline due to climate-related stress and intensified human pressures, despite their key role in sustaining regional biodiversity. Soil health and the crucial symbiotic partnership between oak trees and arbuscular mycorrhizal fungi (AMF) are crucial for resilience in drought-prone Mediterranean environments. Due to a lack of comprehensive studies, this research aimed to analyze the root-associated microbiome of Persian oak (Quercus brantii) across western and southwestern Iran, specifically focusing on AMF diversity and their ecological role. Our study employed Illumina high-throughput sequencing of ITS and 18 S rRNA V4 markers of root-associated fungal communities to assess taxonomic composition and diversity of 160 trees across eight different sites. Analyses revealed dominant fungal groups, including key AMF taxa like Glomeraceae and Claroideoglomeraceae, with significant spatial variation in diversity and community structure, likely influenced by regional and abiotic factors. In addition, the findings highlight the important ecological function of the Persian oak canopy in creating a favorable microclimate and the essential symbiotic partnership with AMF for drought tolerance and nutrient uptake. However, our study ultimately concludes that despite this crucial symbiosis, the Zagros oak forests remain highly vulnerable to increasing pressures from agricultural expansion and the escalating impacts of climate change, seasonal wildfires, and declining groundwater levels, which pose significant threats to their long-term survival.

Arbuscular mycorrhizal fungi (AMF) are known to alleviate cadmium (Cd) toxicity in plants; however, the conditions that maximize their efficiency remain poorly understood. While previous meta-analyses have documented general benefits of AMF in Cd-contaminated soils, none has systematically examined the interactive roles of soil pH, inoculant type, and plant biomass on Cd dynamics within the soil-plant system. Here, we present a comprehensive global meta-analysis (97 studies; >500 observations) using advanced statistical approaches, random-effects modeling, meta-regression, and structural equation modelling, to identify these key boundary conditions. AMF inoculation significantly (p < 0.0001) enhanced plant biomass, root and shoot length, and chlorophyll content, while markedly reducing shoot Cd concentration. Effects on antioxidant enzymes were variable and generally non-significant. Notably, AMF efficiency was strongly context-dependent: benefits were greater in acidic soils, and microbial consortia outperformed single-species inoculants in high-biomass plants by promoting root Cd immobilization. In contrast, total soil Cd concentration was a weak predictor of AMF effectiveness (meta-regression R² ≤ 2.03%), indicating that Cd bioavailability, largely determined by pH, is more critical than total metal load. Overall, our findings provide robust evidence that AMF symbiosis is a key bio-based strategy for mitigating Cd stress in plants. This study highlights soil pH, inoculant composition, and plant biomass as critical determinants of AMF efficiency and offers practical guidance for optimizing AMF-based phytostabilization and remediation in Cd-contaminated agroecosystems.

The amount of soluble inorganic phosphate (Pi) in soils is typically low and limiting plant growth. Roots of trees in several forest ecosystems form association with ectomycorrhizal (ECM) fungi, where fungi forage and supply inorganic nutrients, such as Pi, in exchange for fixed carbon. While adaptations of model fungi, such as Saccharomyces cerevisiae, to Pi deficiency has been extensively studied, much less is known about how mycorrhizal fungi adapt to Pi deficiency. This study aimed to decipher how the free-living ECM Laccaria bicolor mycelium adapts to Pi deficiency. L. bicolor grown for 7 days in medium without Pi showed very low Pi and polyphosphate reserves and displayed less compact colonies with spreading hyphae. Pi deficiency resulted in approximately 1500-2000 genes being up- and down-regulated more than 2-fold compared to mycelium grown with abundant Pi, with most genes partially reverting their expression pattern in cultures spiked with Pi for 24 hours. Numerous genes involved in Pi mobilization from organic sources, such as phosphatases and ribonucleases, were induced by Pi deficiency, as well as genes involved in Pi transport, and such expression patterns correlated with increased enzymatic activities. Pi deficiency also induced the synthesis of the betaine lipid diacylglyceryl-N,N,N-trimethylhomoserine (DGTS). Several genes induced by mycorrhization, such as those encoding protease inhibitors belonging to the mycocypin family and Mycorrhizae-Induced Small Secreted Peptides (MiSSP), were also induced by Pi deficiency. Altogether, this study shows that L. bicolor can robustly respond to Pi deficiency and identifies parallels between these adaptations and those involved in mycorrhization.

Ectomycorrhizal (ECM) fungi play a vital role in the bioremediation of heavy metal contaminated soil and protecting the host plants from metal stress. In this study, we employed a comparative proteomic approach to investigate the molecular response of ECM fungus Laccaria bicolor to cadmium (Cd) stress. Out of total 997 proteins identified, 154 proteins with a fold change ≥ 1.5 and p < 0.05 were classified as differentially abundant proteins (DAPs) and selected for analysis. KEGG-based functional annotation revealed that Cd exposure disrupted key metabolic pathways including carbohydrate, nucleotide and energy metabolism, thereby inducing cellular energy stress. Proteins involved in genetic information processing, such as DNA replication, repair, transcription, translation, and protein folding, were significantly downregulated, indicating genomic instability and impaired protein quality control. Furthermore, Cd stress affected cellular homeostasis by altering membrane transport and vesicular trafficking systems. In response, L. bicolor activated multiple defense mechanisms to counteract the Cd toxicity, notably upregulating the proteins involved in oxidative stress mitigation, particularly those associated with glutathione metabolism, as well as MAPK and calcium signaling pathways. The consistent upregulation of glutathione and many other related enzymes highlight their central role in Cd detoxification. Overall, this study provides comprehensive insights into the molecular strategies deployed by L. bicolor for Cd tolerance, identifying potential biomarkers and target genes for future biotechnological applications in phytoremediation and stress resilience. Also, this study highlights the active role of glutathione biosynthesis and metabolism proteins in Cd stress mitigation.

We evaluated the effects of arbuscular mycorrhizal fungi (AMF) inoculation on growth, root system architecture, and photosynthetic performance of Coffea arabica seedlings. In a greenhouse experiment using unsterilized soil, seedlings were grown either with (+ M) or without (-M) the addition of AMF inoculum. +M plants exhibited higher net CO₂ assimilation rates and maximum carboxylation capacity of RuBisCO despite reduced stomatal conductance (and transpiration rates), resulting in improved water-use efficiency. These physiological adjustments were associated with greater photochemical utilization of incident light. In addition, +M plants showed increased foliar phosphorus concentration and shifts in leaf metabolic profiles, characterized by higher starch and total free amino acids, reduced hexose sugars, and unchanged sucrose and protein concentrations. Compared with -M plants, +M seedlings displayed pronounced modifications in root system architecture, including greater total root length, surface area, and volume, with a higher proportion of fine roots, while biomass partitioning remained unchanged. Collectively, these morphological and physiological responses resulted in superior vegetative growth in + M plants. AMF inoculation thus represents a promising approach to produce more vigorous and stress-resilient coffee seedlings, potentially facilitating field establishment and reducing production costs.

Arbuscular mycorrhizal fungi (AMF) are ubiquitous in arid ecosystems, yet their distribution and community structure along spatial and ecological gradients remains insufficiently explored at regional scales. Here, we employed Malva sylvestris L., a native spontaneous plant species, to investigate the distribution patterns, phylogenetic structure, and community interactions of AMF and the associated root microbiome in dryland ecosystems. Sampling was conducted along a 700 km transect extending from the Atlantic coast to inland Morocco, encompassing predominantly semi-arid ecosystems. Amplicon sequencing of the LSU rDNA region of roots and soil samples revealed a highly diverse AMF assemblage spanning ten families, including Domikaceae, Diversisporaceae, Entrophosporaceae, Sclerocystaceae, and Septoglomeraceae, while the most frequent taxa belonged to the genera Dominikia, Entrophospora, Funneliformis, and Rhizophagus. Phylogenetic alpha diversity declined with increasing soil phosphorus (P) and nitrogen (N) but increased with soil potassium, precipitation, and distance from the coastline. AMF community dissimilarity in the rhizosphere was primarily explained by distance from the coastline, MAT, and precipitation together with soil P, N, whereas AMF communities in roots were mainly structured by soil P, N, and carbon. Community assembly processes among root-associated AMF were mainly shaped by total soil N and P: total N drove local AMF community structure (positive Nearest Taxon Index) while variation in soil P increased community turnover among locations (positive beta Nearest Taxon Index). Consequently, network topology was negatively correlated with soil P, and temperature, but positively with precipitation. Specialized AMF taxa, particularly Septoglomus and Funneliformis, acted as hubs in the root fungal network, whereas generalists such as Rhizophagus and Entrophospora drove cross-kingdom associations, interacting strongly with Rhizobium, Sphingomonas, and Caulobacter. Overall, this study advances our understanding of AMF ecology in dryland ecosystems and introduces an innovative bioinformatic workflow that provides new opportunities for exploring mycorrhizal diversity and functions.