Search Results (897)

Arbuscular mycorrhizal (AM) fungi establish mutualistic symbiosis with most land plants, facilitating mineral nutrient uptake in exchange for photosynthates. As one of the most commercially used rootstocks in citrus, Poncirus trifoliata heavily depends on AM fungi for nutrient absorption. The GRAS gene family plays essential roles in plant growth and development, signaling transduction, and responses to biotic and abiotic stresses. However, the identification and functional characterization of GRAS family genes in P. trifoliata remains largely unexplored. In this study, a comprehensive genome-wide analysis of PtGRAS family genes was conducted, including their identification, physicochemical properties, phylogenetic relationships, gene structures, conserved domains, chromosome localization, and collinear relationships. Additionally, the expression profiles and protein interaction of these genes under AM symbiosis were systematically investigated. As a result, 41 GRAS genes were identified in the P. trifoliata genome, and classified into nine distinct clades. Collinearity analysis revealed seven segmental duplications but no tandem duplications, suggesting that segmental duplication played a more important role in the expansion of the PtGRAS gene family compared to tandem duplication. Additionally, 18 PtGRAS genes were differentially expressed in response to AM symbiosis, including orthologs of RAD1, RAM1, and DELLA3 in P. trifoliata. Yeast two-hybrid (Y2H) screening further revealed that PtGRAS6 and PtGRAS20 interacted with both PtGRAS12 and PtGRAS18, respectively. The interactions were subsequently validated through bimolecular fluorescence complementation (BiFC) assays. These findings underscored the crucial role of GRAS genes in AM symbiosis in P. trifoliata, and provided valuable candidate genes for improving nutrient uptake and stress resistance in citrus rootstocks through molecular breeding approaches. Full article

Background/Objectives:Maerua crassifolia, a threatened medicinal species endemic to drylands, exhibits a pronounced drought sensitivity. Despite the critical role of microorganisms, particularly bacteria and fungi, the microbial consortia in M. crassifolia’s rhizosphere remain underexplored. Methods: Metagenomic whole genome shotgun sequencing (WGS) was employed to elucidate the taxonomic composition of bacterial and fungal communities inhabiting the soil rhizosphere of M. crassifolia. Results: The data revealed a marked predominance of bacterial genomes relative to fungal communities, as evidenced by non-redundant gene analysis. Notably, arbuscular mycorrhizal fungi (AMF), specifically Rhizophagus clarus, Rhizophagus irregularis and Funneliformis geosporum, are key rhizosphere colonizers. This study confirmed the presence of phosphate-solubilizing bacteria (PSB), such as Sphingomonas spp., Cyanobacteria and Pseudomonadota, underscoring the critical role of these microorganisms in the phosphorus cycle. Additionally, the study uncovered the presence of previously uncharacterized species within the phylum Actinobacteria, as well as unidentified taxa from the Betaproteobacteria, Gemmatimonadota and Chloroflexota phyla, which may represent novel microbial taxa with potential plant growth-promoting properties. Conclusions: Findings suggest a complex, symbiotic network where AMF facilitate phosphorus uptake through plant–root interactions. In a tripartite symbiosis, PSB enhance inorganic phosphorus solubilization, increasing bioavailability, which AMF assimilate and deliver to plant roots, optimizing nutrition. This bacterial–fungal interplay is essential for plant resilience in arid environments. Future investigations should prioritize the isolation and characterization of underexplored microbial taxa residing in the rhizosphere of M. crassifolia, with particular emphasis on members of the Actinobacteria, Betaproteobacteria, Gemmatimonadota and Chloroflexota phyla to uncover their roles in nutrient acquisition and sustainability. Full article

Arbuscular mycorrhizal fungi (AMF) play a pivotal role in sustainable agriculture by enhancing nutrient efficiency and reducing the dependence on synthetic fertilizers. Developing these sustainable, effective products requires knowledge of the target plant and its associated microbial communities in the production landscape of interest. This study focused on AMF populations associated with Tir wheat in six main locations of Türkiye’s Van Lake Basin. The Erçek-Özalp-Saray region exhibited the highest organic matter values. Higher available phosphorous contents were found for Erciş-Patnos and Muradiye. The Erciş-Patnos region exhibited the highest AMF density (120 spores/10 g soil) and frequency (75%), while the lowest AMF density (45 spores/10 g soil) was recorded in Muradiye. Sand contents correlated positively with spore number and mycorrhizal frequency and negatively with silt and clay. Based on these results, Erciş-Patnos was elected as the best location for the isolation of AMF spores suitable for the development of microbial-based tools for Tir wheat cultivation. These results are very important in the current context of climate change, which mandates the use of low-impact environmental strategies. Further research should explore the interactions of AMFs with other microorganisms to optimize their ecological benefits. However, the results of this study provide a valuable basis for future investigations of AMF-based products for use in sustainable Tir wheat cultivation. Full article

The low availability of phosphorus (P) in soil is one of the main constraints on crop production. Plants have developed several strategies to increase P use efficiency, including modifications in root morphology, the exudation of different compounds, and associations with microorganisms such as arbuscular mycorrhizal fungi (AMF). This study aimed to investigate the effect of sorgoleone compound on AMF colonization and its subsequent impact on P uptake, rhizosphere microbiota, and sorghum growth. The experiment was conducted in a greenhouse using the sorghum genotype P9401, known for low sorgoleone production. Three doses of purified sorgoleone (20 μM, 40 μM, and 80 μM) were added to low-P soil and plants were harvested after 45 days. Treatments included inoculation with the arbuscular mycorrhizal fungi Rhizophagus clarus and a negative control without inoculum. The addition of 40 and 80 μM of sorgoleone did not significantly increase mycorrhization. However, treatment with 20 μM sorgoleone combined with R. clarus inoculation significantly increased total sorghum biomass by 1.6-fold (p ≤ 0.05) compared to the non-inoculated treatment. AMF inoculation influenced only AMF colonization and the fungal microbiota, without affecting the bacterial community, whereas sorgoleone showed no effect on either. The activities of acid and alkaline phosphatases in the rhizospheric soil did not differ significantly among the treatments. Furthermore, the sorghum genes CYP71AM1, associated with sorgoleone biosynthesis, and Sb02g009880, Sb06g002560, Sb06g002540, and Sb03g029970 (related to phosphate transport induced by mycorrhiza) were significantly upregulated (p ≤ 0.05) in fine roots under these conditions. The 20 μM concentration of sorgoleone can enhance AMF colonization in sorghum and promote plant growth under low-P conditions, without significantly altering the microbiota. Full article

Mining activities cause strong soil alterations, such as heavy metal (HM) pollution, which decreases the diversity of plant communities and rhizospheric microorganisms, including arbuscular mycorrhizal (AM) fungi. The polymetallic Paramillos de Uspallata mine in the Andes Mountains, the first mining exploitation in Argentina, provides a unique scenario to study AM fungal resilience after long-term disturbance following over 40 years of inactivity. This study aimed to analyze mycorrhizal status and AM fungal communities in the mine and a nearby unexploited area and to evaluate their associations with soil parameters to elucidate life history strategies. Long-term exposure to elevated Fe, Pb, Zn, and Ag concentrations and high electrical conductivity (EC, 5.46 mS/cm) led to the dominance of Entrophospora infrequens in association with Pappostipa speciosa, demonstrating that this AM species is a stress-tolerant strategist in symbiosis with a pioneer perennial plant, resilient in the most impacted mine areas. In contrast, the unexploited area, with an EC of 0.48 mS/cm and low HM contents, supported competitive and ruderal species, revealing distinct ecological strategies of AM fungi in disturbed versus undisturbed environments. These findings highlight the potential of E. infrequens for bioremediation and ecological restoration in post-mining landscapes. Full article

Arbuscular Mycorrhizal Fungi (AMF) play a key role in enduring stresses in desert ecosystems, as they enhance the moisture and nutrient supply to desert plants. An investigation was carried out to detect the existence of AMF in the root regions of five perennial native desert grasses of Kuwait (Cenchrus ciliaris L., Cenchrus setigerus Vahl, Lasiurus scindicus Henrard, Pennisetum divisum (Forssk.) Henr., and Panicum turgidum Forssk.) in comparison with a non-native grass (Panicum virgatum L.). The native plants, C. setigerus and P. divisum had the highest colonization (100%) with vesicles, followed by P. turgidum (90%). The colonization of arbuscules was highest in the non-native grass, P. virgatum (60%), followed by C. setigerus (50%). Phylogenetic analysis for molecular identification to determine the genetic diversity of the AMF community in association with the native plant roots of the two dominant desert species, i.e., L. scindicus and P. turgidum, against P. virgatum, revealed a rich diversity. The AMF, Claroideoglomus lamellosum, and Rhizophagus sp. were identified from L. scindicus roots, Rhizophagus iranicus from P. turgidum roots, and Claroideoglomus lamellosum, from the non-native grass, P. virgatum, with almost 98–100% sequence similarity, indicating a significant difference between the mycorrhizal species in the nativity of grasses. This research confirms the diversity of AMF associated with native desert plants and emphasizes their symbiosis and host specificity. Thus, this study provides insight into AMF community structures, functions, and profiling, allowing us to understand their ecological and economic impacts, and ultimately implement strategies for sustainable biodiversity, productivity, and ecosystem management. Full article

The molecular mechanism of arbuscular mycorrhizal fungi (AMF) in reducing cadmium (Cd) accumulation in plants remains unclear. In this respect, the effects of Rhizophagus intraradices (Ri) inoculation under Cd stress on rice growth, the uptake of Cd along with other elements, and the expression of Cd transport genes, including OsNRAMP1/5, were studied using wild-type (WT) and osnramp5 mutant rice. The results showed that Ri inoculation did not affect rice growth. The uptake of Cd of the osnramp5 mutant was much lower than the WT, as 27.6%, 17.5%, and 39.9% of Cd were noted in the grains, shoots, and roots, respectively. For the WT, Cd alone significantly promoted the OsNRAMP5 expression in shoots, but Ri inoculation significantly suppressed OsNRAMP5 expression and significantly reduced its grain and shoot Cd by 44.4% and 62.3%, respectively, compared to the Cd alone treatment. In contrast, for the osnramp5 mutant, Ri inoculation did not influence OsNRAMP5 expression or the grain and shoot Cd. Furthermore, the expression of other Cd transporters (OsIRT1, OsZIP3/7, OsCAX1a) in both varieties were not changed under the treatments. In conclusion, Ri inoculating significantly reduced Cd uptake by rice, with the molecular mechanism by negative regulation of expression of the OsNRAMP5 gene. Full article

Verticillium wilt of olive (VWO), caused by Verticillium dahliae (Vd), represents a significant threat to olive cultivation, particularly to the Moroccan cultivar “Picholine Marocaine”, by reducing yield, tree survival, and overall productivity. Current chemical and cultural control strategies provide limited efficacy, highlighting the need for alternative approaches such as biological control. This study investigated the potential of Rhizophagus irregularis (RI) as a biological agent to mitigate VWO over a 10-month period following V. dahliae inoculation. Disease severity, incidence, and defoliation rate as well as oxidant stress markers, antioxidant enzyme activities, and the phenolic pathway were evaluated in a greenhouse experiment. Our results showed that R. irregularis significantly reduced (p < 0.05) disease severity and incidence by about 31% and 26%, respectively, and decreased defoliation rates by 35% in RI-infected plants (RIV). The presence of R. irregularis triggered enhanced antioxidant enzyme activities (e.g., superoxide dismutase, catalase, and polyphenoloxidase), increased lignin deposition, elevated phenylalanine ammonia-lyase activity, and increased total phenol content in olive tissues. These biochemical and structural changes reduced lipid peroxidation, oxidative stress, and physiological damage, resulting in delayed disease progression. Enhanced accumulation of lignin and total phenolic compounds, particularly in aboveground tissues, was observed. This likely reinforced cell walls and enhanced resistance to pathogen infection. This study demonstrates that R. irregularis offers a promising biocontrol agent for combating soil-borne diseases in olives and other susceptible crops by mitigating VWO, boosting antioxidant defenses, and modulating the phenolic pathway with tissue-specific responses. Full article

Arbuscular mycorrhizal fungi (AMF) affect cadmium (Cd) accumulation and tolerance in host plants. However, the effects of AMF on Cd accumulation and phytotoxicity and their underlying mechanism in apples remain uncharacterized. In this study, the comprehensive physiological and molecular responses of uninoculated and Rhizophagus intraradices-inoculated Malus hupehensis Rehd. rootstocks exposed to 0 or 300 μM Cd were investigated. AMF inoculation mitigated Cd-induced growth and photosynthesis inhibition and nutrient ion disorders. It also lowered the concentrations of Cd in all tissues and reduced Cd transport to the shoots. Compared to uninoculated apple plants, those inoculated with mycorrhizal fungi reduced the mobility and toxicity of Cd by altering its form and binding it to the cell walls of the roots and leaves. AMF inoculation ameliorated Cd stress by altering endogenous phytohormone levels and triggering enzymatic and non-enzymatic antioxidant systems. Transcriptome analysis revealed that the differentially expressed genes (DEGs) associated with AMF under Cd stress regulated carbohydrate and amino acid biosynthesis and metabolism, as well as phytohormone biosynthesis and signal transduction. Furthermore, AMF inoculation downregulated certain genes involved in Cd uptake and transport while upregulating other genes involved in detoxification. These results suggest that AMF alleviate Cd phytotoxicity by orchestrated physiological and transcriptomic regulation in M. hupehensis Rehd., providing valuable insights into the efficacy of AMF inoculation in improving the heavy metal resistance of fruit trees. Full article

Solanum lycopersicum, a widely cultivated vegetable crop globally, faces soil cadmium (Cd) contamination issues due to Cd’s high mobility, posing potential threats to Solanum lycopersicum growth and human health. In light of this, this study selected three representative Solanum lycopersicum varieties: Micro Tom, Red Guanyin, and Taiwan Pink King, and designed a series of experiments to investigate their growth performance under Cd stress. Experimental treatments included the sole application of different concentrations of Vitekang soil conditioner (VT), as well as the individual and combined application of VT and arbuscular mycorrhizal fungi (AMF). By thoroughly analyzing agronomic traits, cellular membrane lipid peroxidation levels, the activities of antioxidant enzymes (Catalase (CAT), Superoxide Dismutase (SOD), and Peroxidase (POD)), and the expression levels of genes related to Cd transport and detoxification (SLNRAMP6 and SlHMA3), this study comprehensively evaluated the effectiveness of different treatments in mitigating Cd stress in the three Solanum lycopersicum varieties. The results indicated that when VT was applied at a concentration of 2.4 g/kg in combination with AMF, it significantly reduced the detrimental effects of Cd on Micro Tom, Red Guanyin, and Taiwan Pink King. The specific experimental outcomes were as follows: (i) significantly decreased Cd accumulation in Solanum lycopersicum roots and leaves; (ii) effectively mitigated cellular membrane lipid peroxidation; (iii) significantly increased antioxidant enzyme activities; and (iv) influenced expression patterns of genes related to Cd transport and detoxification. This study further confirms that, compared to the sole application of VT or AMF, the combined application of these two treatments serves as a more effective practical method, exhibiting significant advantages in alleviating soil Cd contamination, promoting Solanum lycopersicum growth, and improving agronomic traits. This study not only advances research progress on VT and AMF in Solanum lycopersicumes, providing a solid theoretical and experimental foundation for cultivating high-quality Solanum lycopersicumes, but also holds significant importance for improving and optimizing the “VIP+N” technology, achieving farmland soil protection, and enhancing agricultural product quality. Full article

Soil aggregate stability plays a pivotal role in ecosystem functioning and carbon sequestration. Nitrogen deposition influences aggregate stability and drives differential responses in AM and ECM fungi, yet the underlying mechanisms remain unclear. This study aimed to determine how N addition influences soil aggregation, mycorrhizal morphological characteristics, and soil organic carbon (SOC) across two mycorrhizal types. A temperate forest experiment was conducted in northeastern China using 12 plots subjected to four N treatments (control, low, medium, high). Soil properties, soil aggregate traits, mycorrhizal morphological characteristics, and aggregate distributions were quantified. Relationships were examined via correlation analyses, random forest models, and structural equation modeling. N enrichment substantially increased SOC and soil water content, enhancing the proportion of large soil aggregates (4–8 mm) and elevating mean weight diameter (MWD) and geometric mean diameter (GMD), two critical indicators of soil aggregate stability. AM fungi exhibited a stronger response to N addition than ECM, reflected in greater hyphal development and carbon accumulation. SOC and water content correlated positively with aggregate stability, whereas soil pH showed a negative association. N inputs enhance soil structural stability by promoting SOC and water retention, with AM fungi demonstrating heightened sensitivity to N addition. These findings emphasize the integral role of mycorrhizal dynamics in shaping soil carbon stabilization under increasing N deposition. Full article

An indigenous consortium of arbuscular mycorrhizal fungi (AMF) from the Figuig oasis in southern Morocco, comprising Rhizophagus sp., Funneliformis sp., Acaulospora sp., Sclerocystis sp., and Scutellospora sp., was evaluated for its effects on the growth and sensitivity of Phoenix dactylifera L. variety (cv. Boufeggous Gharas) to Fusarium oxysporum f. sp. Albedinis (Foa), the causal agent of Bayoud disease. Despite its high fruit quality and local appreciation, the Boufeggous Gharas variety is highly susceptible to Foa and is currently at risk of extinction, underscoring the urgent need for its sustainable management. The results demonstrated that Boufeggous Gharas seedlings inoculated with a consortium of indigenous AMF showed significantly improved shoot and root length, leaf number, and biomass as compared to non-mycorrhized seedlings. In contrast, Foa-infected seedlings showed significantly reduced growth, with a 46.6% decrease in shoot height and a 50.4% reduction in root length compared to non-infected seedlings. Interestingly, AMF inoculation mitigated this sensitivity to Foa, significantly restoring growth parameters. Seedlings treated with AMF + Foa showed a 51% increase in shoot height and a 61% improvement in root length, along with over 100% gains in shoot and root biomass compared to seedlings infected solely with Foa. This study provides the first evidence of integrating AMF into sustainable date palm cultivation practices to mitigate the impacts of biotic stresses, thereby promoting the preservation and valorization of vulnerable date palm varieties. The protective effects of AMF are attributed to improved nutrient uptake, enhanced root architecture, and systemic resistance induced by AMF colonization. Full article

Reducing the use of chemical inputs is becoming a major challenge in developing sustainable agriculture. Fungi, known as biocontrol agents (BCAs) and biofertilisers, are crucial in scientific research and are celebrated for their efficacy, eco-friendliness, and multifaceted roles. In this study, a bibliometric analysis was conducted on 5349 articles related to fungi as BCAs and biofertilisers over the past half-century using the Web of Science Core Collection (WoSCC) database. The publications on fungi, such as BCAs and biofertilisers, have increased significantly over the last 20 years, with a maximum growth rate of 33.7%. The USA and China lead in this field. Keyword clustering analysis revealed that entomopathogenic fungi, including Hemiptera, Coleoptera, and Lepidoptera, can be used to manage plant pests. It also showed that fungi can be used as biofertilisers to promote plant growth. The analysis of research trends shows that Beauveria bassiana in biological control is highly significant. This study also showed that entomopathogenic fungi control plant pests by infiltrating the insect cuticles. Trichoderma spp. exert biocontrol effects by producing antibiotics. Arbuscular mycorrhizal fungi can trigger plant defence mechanisms by modulating secondary metabolite synthesis. This study contributes to the current knowledge of fungi as BCAs and biofertilisers and can guide future research. Full article

Nitrogen (N) deposition and carbon (C) addition significantly influence the dynamics of plant–microbe interactions, particularly altering the symbiotic relationship between plants and arbuscular mycorrhizal fungi (AMF). However, the effects and underlying mechanisms of labile C input on the relationship between AMF and various plant species in a nitrogen-enriched environment remain a knowledge gap. A seven-year field experiment was conducted to examine how six levels of N and three levels of labile C addition impact AMF colonization in four key plant species: Leymus chinensis (Trin. ex Bunge) Tzvelev, Stipa baicalensis Roshev., Thermopsis lanceolata R. Br. and Potentilla bifurca Linn. Our results showed that N and C additions exert significantly different effects on the relationship between AMF and various plant species. Labile C addition mitigated historical N negative effects, particularly for S. baicalensis, enhancing AMF infection and promoting nutrient exchange under high-N and low-C conditions. The relationship between AMF and both L. chinensis and T. lanceolata changed to weak mutualism under low-N and high-C conditions, with significant decreases in vesicular and arbuscular abundance. Plant root stoichiometry plays a critical role in modulating AMF symbiosis, particularly under high-N and -C conditions, as reflected in the increased AMF infection observed in T. lanceolata and P. bifurca. Our findings emphasize the species-specific and nutrient-dependent AMF symbiosis, revealing that targeted C input can mitigate the legacy effects of N enrichment. Effective nutrient management is of crucial importance for ecological restoration efforts in temperate grasslands affected by long-term N enrichment. Full article

Agriculture remains a key contributor to Central America’s economy, despite climate change posing a significant threat to the sector. In the Trifinio region, already afflicted by arid summers, temperatures are expected to rise in the near future, potentially exacerbating the vulnerability of smallholder farmers. This study investigates the effects of two fungal symbionts, Trichoderma asperellum (TR) and the Arbuscular mycorrhiza fungi (AMF) Glomus cubense, and agronomic choices and practices such as cultivar selection, substrate type, and fertigation management on tomato (Solanum lycopersicum L.) seedling growth and quality. Results showed that nutrient solution and the adoption of forest topsoil as substrate significantly enhanced morphological, physiological, and quality parameters. Modifying the nutrient solution to allow for an increase in plant height of 170% and a dry weight of 163% and enhancing Dickson’s quality index (DQI) by 64.5%, while the use of forest topsoil resulted in plants 58.6% higher, with an increase of 101% in dry weight and of 90.1% in the DQI. Both T. asperellum and G. cubense had positive effects on specific growth parameters; for instance, TR increased leaf number (+6.95%), while AMF increased stem diameter (+3.56%) and root length (+19.1%), although they did not, overall, significantly increase the seedling’s biomass and quality. These findings underscore the importance of agronomic practices in mitigating the impacts of climate change on tomato production, offering valuable insights for farmers in semi-arid regions. Full article