Soil heavy metal (HM) pollution poses a severe threat to ecological security and human health. Selenium (Se) is an essential trace element for the human body and can regulate crop growth and development as well as HM uptake in HM-contaminated soils. The regulatory mechanisms of Se on HMs are mainly reflected in four aspects: Geochemical immobilization promotes the formation of metal selenide precipitates and the adsorption of HMs by soil colloids by regulating the rhizosphere redox potential (Eh) and pH value. Rhizosphere microbial remodeling drives the enrichment of functional microorganisms such as Se redox bacteria, plant growth-promoting rhizobacteria (PGPR), and arbuscular mycorrhizal fungi (AMF) through the dual selective pressure of Se toxicity and root exudates, in order to synergistically realize Se speciation transformation and HM adsorption/chelation. Root barrier reinforcement constructs physical and chemical dual defense barriers by inducing the formation of iron plaques on the root surface, remodeling root morphology and strengthening cell wall components such as lignin and polysaccharides. Intracellular transport regulation down-regulates the genes encoding HM uptake transporters, up-regulates the genes encoding HM efflux proteins, and promotes the synthesis of phytochelatins (PCs) to form HM complexes and lastly realizes vacuolar sequestration. Finally, we summarize current research gaps in the interaction mechanisms of different Se species, precise application strategies, and long-term environmental risk assessment, providing a theoretical basis and technical outlook for the green remediation of HM-contaminated farmlands and Se biofortification of crops.

Presymbiotic activation of karrikin signaling creates a permissive state for arbuscular mycorrhizal symbiosis by derepressing the NSP1-NSP2-SLR1 transcriptional complex in rice.

Understanding how litter diversity and soil fauna drive microbial communities is critical for revealing trophic cascades in decomposition processes. We conducted a 460-day field decomposition experiment in a subtropical forest, placing litter mixtures of one to four tree species into mesh bags with 25 μm or 4 mm openings to create fauna-excluded and fauna-accessible treatments, and assessing microbial community composition and biomass using phospholipid fatty acid (PLFA) analysis. The results showed that the litter traits and diversity significantly influenced microbial PLFA content. Both fungal and bacterial PLFA content increased with higher levels of nitrogen, phosphorus, manganese, potassium, and leaf thickness in the mixed litter. Soil fauna had a significant impact on microbial PLFA content and its community distribution. A notable interaction between soil fauna and litter richness was observed: soil fauna slowed the decline of bacterial PLFA content as litter richness increased, highlighting their role in moderating the impact of litter diversity on microbial communities. Additionally, soil fauna reversed the relationship between mixed litter traits and arbuscular mycorrhizal fungi (AMF) PLFA content. While a negative correlation was observed in the absence of soil fauna, their presence turned it positive, demonstrating that soil fauna modifies the impact of litter traits on AMF. These findings demonstrate the intricate interactions between plant litter diversity, soil fauna, and microbes, highlighting the crucial role of soil fauna in modulating the effect of plant diversity on microbial communities during decomposition.

Plant-based dyes as eco-friendly alternative for visualization of arbuscular mycorrhizal fungi.

Impact of indigenous soil microbes on switchgrass tolerance to lead stress.

Arbuscular mycorrhizal fungi regulate community structure of nitrogen metabolizing bacteria and mitigate nitrogen losses in soil contaminated with tetracycline

Combined use of arbuscular mycorrhizal fungus and silkworm excrement reduces cadmium accumulation in rice: The roles of iron plaque, soil chemical properties, and microbial community structure

Arbuscular mycorrhizal (AM) fungi form symbiotic relationships with over 80% of terrestrial plants, enhancing nutrient exchange. This review synthesizes research on AM fungi's roles in mediating nitrogen (N), phosphorus (P), and carbon (C) dynamics and their impacts on plant growth. AM fungi facilitate nutrient acquisition through extensive hyphal networks and interactions with nitrogen‐fixing bacteria, boosting N fixation and transport. They enhance P uptake and maintain C: N P stoichiometry, improving root growth and nutrient absorption in nutrient‐poor soils. AM fungi also mitigate nutrient toxicity and increase plant resilience to abiotic stresses, serving as natural biofertilizers. In sustainable agriculture, they reduce chemical fertilizer use by improving nutrient cycling and soil aggregation, enhancing soil health and crop resilience. Despite these benefits, gaps remain in understanding species‐specific interactions and environmental influences on AM fungi efficacy, necessitating further research. This review provides a comprehensive overview of AM fungi's contributions to nutrient dynamics, offering insights for advancing mycorrhizal research and sustainable farming practices.

Integrating fall-planted cover crops (CC) and arbuscular mycorrhizal (AM) fungi into hardneck garlic production can enhance the sustainability of garlic production in the northeast. We hypothesized that relay intercropping (RI) garlic into standing CC and inoculating with commercially available AM fungi would (i) influence garlic bulb yield and nutrient concentration as a result of increased nutrient retention in CC residues and (ii) enhance the nitrogen use efficiency (NUE) of garlic production by providing an alternative N source (decomposing CC residues) to garlic plants in spring. Garlic yield response to RI depended on CC fall biomass accumulation (2301-3696 kg ha-1 dry weight in 2021, < 1500 kg ha-1 in 2020). Interspecies competition between CC and garlic reduced bulb yield by 21-31% in RI treatments compared to the no cover crop control in 2021. Although bulb N, P, K and Mn assimilation was negatively impacted in the first year, nutrient concentrations were normalized in the second cropping season, suggesting that multiple years are necessary to improve garlic quality under a RI system. Garlic yield and nutritional quality were not significantly improved by AM fungi inoculation in this study. NUE was optimized under oat RI systems, which had the highest yields among RI treatments in the second year. RI with CC can improve NUE of garlic production systems, but CC should be managed appropriately to avoid reductions in bulb yield. Multi-year implementation of RI balances nutrient assimilation by garlic, which was negatively impacted in the first year of production. © 2025 Society of Chemical Industry.

Abstract Background and aims Arbuscular mycorrhizal fungi (AMF) play an essential role in plant nutrition in both natural and agro-ecosystems. However, how soil nutrient availability simultaneously regulates AMF diversity and contribution to plant nutrition, requires more attention. We hypothesised that the interaction between the availability of key soil macronutrients phosphorus (P) and nitrogen (N) regulates AMF contribution to wheat nutrition and that nutrient availability will simultaneously influence AMF community composition. Methods We tested this using a unique long-term P fertilisation trial, sampling wheat roots across two growing seasons. Expression of wheat mycorrhizal nutrient transporters was quantified by RT-qPCR and AMF communities were characterised by ITS2 metabarcoding. Complementary experiments under controlled conditions examined how the interaction between P and N regulates arbuscular mycorrhizal function in plant nutrition. Results Field-grown wheat showed campaign-specific effects of P fertilisation on AMF colonisation and nutrient transporter expression, which coincided with shifts in plant N status. Controlled experiments confirmed that colonisation depends on the limitation of either P or N, but that the regulation of peri-arbuscular phosphate, ammonium and nitrate transporters depended on the limiting nutrient. AMF communities also responded to soil P availability, with the genus Funneliformis consistently dominating under high P conditions. Conclusions Our findings demonstrate that P and N availability jointly shape root AMF communities and regulate their nutritive function in wheat. The combination of community profiling and mycorrhizal molecular markers provides a valuable approach for understanding the AMF contribution to plant nutrition across agroecosystems, and therefore can be used for optimising agroecological practices.

Soil contamination by zinc (Zn) is a limiting factor for plant productivity and an environmental risk in intensive agricultural systems. Arbuscular mycorrhizal fungi (AMF) are symbiotic associations capable of modifying metal dynamics in the rhizosphere, contributing to the acquisition, immobilization, or controlled translocation of Zn under stress conditions. The aim of this study was to evaluate the potential of AMF to enhance Zn phytoextraction in contaminated soils from Mocache, Ecuador, using Oryza sativa as a trap plant. Sixteen AMF species were identified, including Claroideoglomus lamellosum, Acaulospora colombiana, A. koskei, and A. bireticulata, all exhibiting low spore densities. Rice plants were inoculated with a commercial inoculum and exposed to Zn concentrations of 100, 150, and 200 mg kg⁻¹. Significant differences in plant height and number of leaves were observed among treatments, reflecting the interaction between AMF inoculation and metal stress. Although the analysis of variance did not show significant differences in soil Zn concentrations after the experiment, inoculated units showed decreasing trends. The findings indicate that AMF inoculation can enhance agronomic performance and support Zn phytoextraction, representing a viable alternative for the remediation of metal-contaminated agricultural soils.

Effects of Selected Arbuscular Mycorrhizal Fungi, Rock Phosphate, and Compost on Growth and Nutrient Uptake of Citrus Seedlings

Industrial hemp offers several advantages for phytomanaging metal(loid)-contaminated soils as it can provide valuable biomass notably for bioenergy while accumulating some metals (i.e., Cd and Zn) in its shoots. In a previous pot study humic/fulvic acids (HFA) incorporated into the soil with arbuscular mycorrhizal fungi (AMF) enhanced hemp growth. This study assessed the biostimulant effect of HFA, alone or paired with AMF (HFAxAMF), on the shoot yield and shoot Cd, Pb and Zn uptakes in a 2-year field trial in view of producing clean, renewable liquid biofuels. The trial (0.07 ha) was carried out at a contaminated agricultural field in a randomized split-plot design (nine blocks). Cannabis sativa L. was sown at a density of 173 000 plants ha−1. Effects of HFA and HFAxAMF treatments on the behavior of metals and plants were compared to an unamended one. Hemp produced on average 10.7 (year 1)–14.5 (year 2) t DW ha−1 despite a severe drought in year 1. Neither HFA nor HFAxAMF treatments enhanced shoot yield. Shoot Cd, Pb and Zn uptakes reached 9.9, 230, and 869 g ha−1 year−1, respectively. In year 2, shoot Cd uptake improved under all treatments and the 0.01 M Ca(NO3)2-extractable soil Cd, Pb and Zn concentrations at harvest decreased by 95, 79 and 96%, respectively. Hemp was a relevant plant species for phytomanaging this metal-contaminated soil under current climatic constraints. The potential bioethanol yield was estimated in the 3851–6481 L ha−1 range. Overall, hemp can simultaneously reduce soil metal availability while producing a biomass convertible into liquid biofuels. This highlights its strong potential as a dual-purpose crop for sustainable and progressive phytoremediation and renewable energy production.

Tea cultivar genotype plays a critical role in shaping rhizosphere microbiome assembly, yet the underlying mechanisms remain poorly understood. This study employed a controlled pot experiment with five widely cultivated Chinese tea cultivars (Camellia sinensis) to investigate how cultivar-specific variation influences rhizosphere microbial communities and their assembly processes. Rhizosphere soil microbiomes (bacterial and fungal communities) and metabolomes were characterized using 16S rRNA and ITS2 amplicon sequencing combined with untargeted metabolomics. Significant differences in rhizosphere metabolite composition, primarily organic acids, fatty acids, and carbohydrates, were observed among cultivars, which corresponded to distinct bacterial and fungal community structures. Redundancy analysis (RDA) revealed that rhizosphere metabolites explained 19.87% of bacterial and 21.63% of fungal community compositional variation, second only to soil physicochemical properties. Neutral community model and modified stochasticity ratio analyses indicated that microbial assembly across cultivars was predominantly deterministic, and rhizosphere metabolite profiles were strongly correlated with microbial community structure. Notably, arbuscular mycorrhizal fungi made up about 11% of the fungal communities in minimally fertilized pot systems, contrasting sharply with their near-absence in conventionally managed systems plantations. These findings demonstrate that tea cultivar genotype significantly shapes rhizosphere microbiome assembly through metabolic differentiation, providing a theoretical foundation for integrating microbiome considerations into tea breeding programs and developing cultivar-specific management strategies.

Increasing nitrogen (N) deposition tends to aggravate phosphorus (P) limitation in subtropical forest ecosystems. Arbuscular mycorrhizal (AM) fungi are believed to improve the plant P supply under P-depleted soil conditions. However, how the AM fungi and their extraradical mycelia impact soil P transformation and subsequent P availability under N-induced P limitation is not fully understood. Using an ingrowth-core design, we quantified the effects of AM mycelia on different soil P pools and potential drivers controlling the transformation and availability of soil P in a subtropical forest receiving N fertilization. Nitrogen addition had greater positive and negative mycelial effects on the soil labile P pools and moderately labile P pools, respectively. This finding indicated that AM mycelia increased the availability of soil P under N deposition by promoting transformation from moderately labile P to labile P. Additionally, we observed diverse mycelial effects under N addition on multiple microbial (P-transformation genes and phosphatase activities) and physiochemical drivers (Al/Fe oxyhydroxides and soil pH) involved in driving soil P transformation. These results suggest that AM mycelia can improve soil P availability to counteract increased P limitation due to N deposition by controlling microbial and physiochemical processes that coregulate soil P transformation. The positive feedback effects of mycorrhizal fungi on soil P transformation and availability as well as the drivers controlling these effects should be incorporated into ecosystem biogeochemical models. This is crucial for accurately predicting forest productivity and function under future N deposition scenarios.

Background Rhizosphere microorganisms play a critical role in plant growth and medicinal quality, yet their altitudinal patterns and interactions with soil nutrients and bioactive compounds in Angelica sinensis ( A. sinensis ) remain poorly understood. Methods Using Illumina MiSeq sequencing, we analyzed bacterial, fungal, arbuscular mycorrhizal (AM) fungal, and archaeal diversity across an altitudinal gradient, alongside soil physicochemical characteristics and bioactive components. Results As cultivation elevation increased, bacterial and fungal diversity initially increased significantly and then stabilized ( p &amp;lt; 0.05). In contrast, AM fungal and archaeal communities remained relatively stable. Bacterial communities varied significantly across altitudes (stress &amp;lt; 0.1, p = 0.001), as did soil nutrients and enzyme activities ( p &amp;lt; 0.05). Bioactive components, except for ferulic acid, varied significantly with altitude. Redundancy analysis (RDA) confirmed that altitude and soil factors are key drivers of microbial community assembly. Mantel tests and structural equation modeling (SEM) demonstrated significant correlations between soil properties, microbial diversity, and medicinal properties of A. sinensis ( p &amp;lt; 0.05). Conclusion The mid-to high elevation zone (2520–2717 m) was identified as optimal for both yield and bioactive compound accumulation. These findings deepen the understanding of how microbes adapt to different altitudes in medicinal plants and offer a framework for precise cultivation of A. sinensis , thereby supporting the high-altitude symbiosis theory.

Arbuscular mycorrhizal (AM) fungi enhance plant nutrition and stress tolerance, yet their agricultural use remains limited because symbiotic outcomes are unpredictable. Mycorrhizal responsiveness (AM-responsiveness)-the host's growth response to AMF inoculation-offers a potential breeding target. We investigated variation in AM-responsiveness among Petunia hybrida, P. axillaris, P. exserta and P. inflata, and explored its genetic and environmental determinants. Plants were inoculated with Rhizoglomus irregulare and analysed for biomass, AMF colonization, phosphate uptake, phosphate transporter expression and accumulation of the foliar biomarker 11-carboxyblumenol C-glucoside. Species differed strongly in colonization intensity, biomass and biomarker accumulation. Based on contrasting AM-responses between P. axillaris and P. exserta, a recombinant inbred line (RIL) population derived from these parents was used to assess AM-responsiveness as a quantitative trait under variable environmental conditions. The RILs showed transgressive segregation for biomass responses, confirming a heritable component, while strong genotype × environment (G × E) interactions demonstrated environmental dependency. These results highlight AM-responsiveness as a genetic trait suitable for breeding but emphasize the need to account for environmental variation. Foliar blumenols proved effective non-destructive indicators of colonization, supporting their potential in high-throughput screening for mycorrhizal traits.

Pesticides are widely distributed in soils1-3, yet their effects on soil biodiversity remain poorly understood4-7. Here we examined the effects of 63 pesticides on soil archaea, bacteria, fungi, protists, nematodes, arthropods and key functional gene groups across 373 sites spanning woodlands, grasslands and croplands in 26 European countries. Pesticide residues were detected in 70% of sites and emerged as the second strongest driver of soil biodiversity patterns after soil properties. Our analysis further revealed organism- and function-specific patterns, emphasizing complex and widespread non-target effects on soil biodiversity. Pesticides altered microbial functions, including phosphorus and nitrogen cycling, and suppressed beneficial taxa, including arbuscular mycorrhizal fungi and bacterivore nematodes. Our findings highlight the need to integrate functional and taxonomic characteristics into future risk assessment methodology to safeguard soil biodiversity, a cornerstone of ecosystem functioning.

Arbuscular mycorrhizal fungi confers resistance to Macrophomina phaseolina in coriander under different nitrogen fertilizer rates

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 18S 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.