Search Results (1,320)

Phyllosphere microorganisms interact with host plants to regulate growth, promote nutrient uptake and enhance stress tolerance with host specificity, while arbuscular mycorrhizal fungi facilitate plant nutrient absorption and stress adaptation. Current poplar microbial studies mostly focus on hermaphroditic species, with limited research on dioecious poplars. This study selected four poplar species commonly hybridized with Populuscathayana and Populus deltoides in the Xinmin area of Liaoning Province as research subjects: two female plants, DM-9-18 and DX-08-01, and two male plants, 2111 and Qingshan poplar. We performed MiSeq high-throughput sequencing targeting bacterial 16S rRNA, fungal ITS, and arbuscular mycorrhizal fungal (AMF) marker genes from poplar phyllosphere, coupled with chemical quantification of leaf, root and rhizosphere soil, to disentangle clone- and sex-associated divergence in microbial assemblages and their core environmental drivers. No significant gender differences were observed in leaf and rhizosphere nutrient levels and microbial α diversity, whereas male poplars had higher rhizosphere soil nutrients. Male and female poplars genotypes harbored distinct microbial ASVs. The dominant phyllosphere microbes and arbuscular mycorrhizal fungi exhibited gender-specific abundance variations, and nutrient content was the key factor shaping microbial communities. This study clarifies microbial community differences among the four selected hybrid poplar clones. While the experimental design confounds sex with host genotype, the observed patterns provide insights into potential sex-related variations. Our results advance the mechanistic understanding of how dioecious poplar genotype and sexual phenotype jointly filter leaf and root-associated microbial symbionts, with applied implications for hybrid poplar breeding and shelterbelt microbial regulation. Full article

Arbuscular mycorrhizal (AM) fungi are often considered host generalists. Although the host-mediated assembly of AM fungal communities is well documented, its functional significance remains poorly understood, particularly in organic and low-input agroecosystems, where crop–weed interactions may influence the soil AM fungal reservoir. We investigated plant and AM fungal functional traits, mycorrhizal dependency (MD), and root AM communities in three legume crops and five weed species grown in pots with the same indigenous AM fungal inoculum. AM fungal communities were characterized using SSU rRNA gene clone libraries, sequencing, and terminal restriction fragment length polymorphism (T-RFLP) analysis. Of 825 examined clones, 792 were assigned to AM fungi, representing 23 RFLP types. Plant species significantly affected the plant traits, root colonization, spore density, extraradical mycelium density, and MD. PERMANOVA revealed that plant species explained 97.3% of the variation in the AM fungal community structure, although this result should be interpreted cautiously because within-species dispersion may have contributed to the explained variance. RELATE analysis showed a significant association between the AM fungal community structure and plant–AM fungal functional traits. The specific root length, shoot and root N concentrations, AM fungal colonization, and spore abundance best explained community patterns. Legume crops supported greater AM fungal development and positive growth responses, whereas several weeds hosted diverse AM communities without showing biomass benefits. These findings highlight that weed management could indirectly influence AM fungal persistence through host-mediated community assembly, although field validation is required. Full article

Pepper fruits contain diverse primary and secondary metabolites, including ascorbic acid, carotenoids, phenolics, and flavonoids, which contribute to nutritional quality, antioxidant capacity, coloration, and consumer acceptance. Chilaca chili pepper (Capsicum annuum L.) is a Mexican cultivar valued for its distinctive flavor and pungency, representing a valuable resource for studying fruit quality and sustainable crop improvement. This study evaluated the individual and combined effects of arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) on growth, physiological responses, antioxidant activity, and fruit quality traits. Twelve treatments in a 3 × 2 × 2 factorial designs were evaluated for chlorophyll, soluble solids, biomass, APX and LOX activities, and vitamin C and capsaicin contents at three ripening stages (green, mid-red, and red). Enzyme activities were determined spectrophotometrically, and bioactive compounds were quantified from methanolic fruit extracts. Microbial inoculation primarily improved fruit physiological quality rather than vegetative growth. Biomass and growth traits showed no significant differences among treatments (p > 0.05), whereas biochemical responses exhibited distinct ripening-dependent patterns. APX activity, vitamin C, and capsaicin increased from green to mid-red stages and declined at full ripeness. Bacillus sp.-based treatments (T1 and T2) produced a significant transient increase in LOX activity during mid-ripening, while T7 showed a similar but weaker response. AMF progressively enhanced LOX activity and capsaicin accumulation in green fruits. PGPR effects were strain-dependent, with Bacillus sp. promoting early capsaicin accumulation and A. deleyi favoring higher levels during advanced ripening. Overall, AMF and PGPR differentially regulate antioxidant metabolism, vitamin C accumulation, and capsaicinoid biosynthesis while interacting with mineral fertilization to improve fruit quality. These findings support beneficial microorganisms as sustainable tools for enhancing nutrient-use efficiency and fruit nutritional and functional value without replacing mineral fertilization. Full article

Bio–tillage can continuously regulate the soil environment through plant roots and rhizosphere biological activities and is considered a low disturbance tillage practice that can alleviate soil compaction. However, long term chemical fertilization alone may limit rhizosphere carbon supply and weaken root–microbe interactions. Whether conservation management can coordinate root adaptation and arbuscular mycorrhizal fungal (AMF) responses to ameliorate the compacted soil environment and improve crop growth remains unclear. This study compared five treatments: chemical fertilizer alone (CN), straw return (SR), organic manure application (OM), straw return combined with organic manure application (SROM), and green manure intercropping (GM). SROM and GM showed the most pronounced soil amelioration effects. Compared with CN, SROM enhanced root tensile strength and elongation at break, increased the relative abundances of Glomus and Claroideoglomus and the accumulation of easily extractable and total glomalin–related soil protein (EE–GRSP and T–GRSP), reduced soil bulk density (BD) by 10.68% and 6.57% in the 0–20 and 20–40 cm soil layers, respectively, and increased MWD and GMD by 78.49–82.08%. The effects of GM were concentrated in the 20–40 cm soil layer, where enhanced soybean root Young’s modulus and complementary interspecific root distribution reduced BD by 7.36% and increased total porosity (TP) by 9.36%. GM also increased AMF root colonization, the relative abundance of Claroideoglomus, and soil nutrient availability. Additionally, SROM generally maintained the highest aboveground dry matter accumulation and exhibited the highest instantaneous growth rate, whereas the current–season growth benefit under GM was relatively limited. These findings highlight the key roles of roots and AMF in soil amelioration and soybean growth and provide a reference for optimizing low disturbance soil management in compacted black soil regions. Full article

Bacterial isolates obtained from spores of the arbuscular mycorrhizal fungi (AMF) have been reported to possess various plant growth-promoting traits. These bacterial isolates enhance plant growth and development through mechanisms such as phytohormone production and nutrient mobilization. The objective of this study was to investigate the ability of bacterial isolates to promote plant development. Five bacterial isolates, Bacillus methylotrophicus, Fictibacillus barbaricus, Stutzerimonas stutzeri, Bacillus aryabhattai, and Priestia aryabhattai, were isolated from AMF (Funneliformis mosseae) spores. The results indicated that all five bacterial isolates promoted plant growth. The greatest positive effects on the tomato seed germination were obtained with Bacillus methylotrophicus and Stutzerimonas stutzeri, with germination percentages of 90% and 95%, respectively. In addition, Stutzerimonas stutzeri enhanced early tomato seedling growth. Priestia aryabhattai produced the highest amount of indole-3-acetic acid (IAA) at 94.43 µg mL⁻¹, which is the auxin phytohormone for plant growth promotion. Furthermore, Bacillus methylotrophicus, Fictibacillus barbaricus, and Bacillus aryabhattai were able to produce high levels of ammonia, which may contribute to improving plant growth in nutrient-deficient environments. In addition, Bacillus methylotrophicus, Bacillus aryabhattai, and Priestia aryabhattai were able to solubilize both phosphate and potassium. These findings suggest that the investigated bacterial strains could be combined with AMF to improve crop establishment and support sustainable agricultural systems by enhancing nutrient availability and reducing dependence on chemical fertilizers. Full article

Soil fungi play key roles in decomposition, nutrient cycling, plant–soil interactions, and soil structure, yet their immediate responses to pesticides remain insufficiently understood. Most studies have focused on long-term, cumulative, or plant-mediated effects, limiting insight into direct impacts. We assessed the short-term direct effects of eight commercial pesticides on fungal abundance, alpha diversity, community composition, trophic structure, and total arbuscular mycorrhizal fungal (AMF) abundance across three contrasting agricultural soils in a plant-free pot experiment. Responses varied strongly among soils and pesticides, with no consistent fungal suppression. Alpha-diversity changed little and inconsistently, whereas community composition shifted markedly, indicating rapid community reorganization before detectable changes in richness or evenness. Soil 1 showed the strongest responses, while Soil 2 was resistant. Although most trophic groups’ relative abundance remained stable, their internal composition was often substantially restructured, suggesting taxonomic turnover without major functional-group shifts. Total AMF abundance increased under several treatments in Soil 1 but decreased under selected treatments in Soil 3. Soil pH was associated with fungal diversity, community composition, and total AMF abundance; however, pesticide-induced pH changes did not consistently explain microbial responses. Overall, short-term pesticide exposure drove selective, soil-dependent community restructuring rather than uniform diversity loss, supporting soil-specific risk assessment. Full article

Arbuscular mycorrhizal fungi (AMF) and rhizobia establish mutualistic symbioses with plant roots. This study focused on their effects on alfalfa (Medicago sativa L.) growth, root morphology, nutritional quality, photosynthetic characteristics, and protein fractions; eight treatments were established: single inoculation with three AMF strains (Funneliformis mosseae, Claroideoglomus etunicatum, Glomus versiforme) or Sinorhizobium meliloti (Sm), dual co-inoculation of each AMF with Sm, and a non-inoculated control (CK). Results showed that all AMF successfully colonized alfalfa roots, with co-inoculation increasing both mycorrhizal colonization rate and nodule number. The F. mosseae × Sm treatment achieved the highest colonization (83.3%) and nodule count (76 per plant). Across two years, this treatment significantly increased aboveground biomass, plant height, and stem diameter (p < 0.05). C. etunicatum × Sm significantly reduced acid detergent fiber content, while dual inoculation markedly improved net photosynthetic rate and light-use efficiency. All inoculations increased rapidly (PB₁) and intermediate-degradable protein (PB₂) but decreased non-protein nitrogen (PA) and bound protein (PC). In conclusion, AMF and rhizobia exhibit significant synergistic effects. Co-inoculation (F. mosseae × Sm and C. etunicatum × Sm) enhances alfalfa productivity by optimizing root structure, improving photosynthesis, and regulating nitrogen metabolism. Full article

Reducing phosphorus (P) fertilization is essential for sustainable agriculture but may compromise crop establishment and productivity. Microbial inoculants, particularly plant growth-promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF), may help reduce fertilizer dependence, yet field evidence for their combined effects under reduced P inputs remains limited. In a single-season field trial under semi-arid Mediterranean conditions, we tested whether single or combined PGPR and AMF inoculations could compensate for a 33% reduction in P fertilization in maize (Zea mays L.). Without inoculation, reduced P decreased hay yield by 17% and plant density by 11%, while grain yield remained unaffected. Single inoculations provided little benefit and did not prevent these declines. In contrast, PGPR-AMF co-inoculation under reduced P fully restored hay yield (8.0 t ha⁻¹) and plant density to levels comparable to those of the 100% P treatment, representing a 21% increase in hay yield relative to uninoculated reduced-P plots. Grain yield per hectare and nutrient concentrations in hay and grain were unaffected by either P reduction or inoculation. Correlation analyses indicated negative associations between stand density and per-plant grain yield and between biomass production and leaf water index, suggesting shifts in resource allocation and plant performance. These findings provide field-scale evidence that PGPR-AMF consortia can buffer the effects of reduced P fertilization on maize establishment and vegetative productivity, supporting their integration into sustainable nutrient management strategies. Multi-season studies are needed to assess the persistence and scalability of these benefits across environments. Full article

Strigolactones (SLs) are multifunctional plant metabolites that govern shoot architecture, facilitate symbiosis with arbuscular mycorrhizal fungi, and trigger seed germination of parasitic weeds, making them attractive targets for crop improvement. Their agricultural potential has been validated in field trials for parasitic weed suppression, drought resilience, and grain yield improvement. However, a major challenge is decoupling their beneficial effects from undesirable functions. To address this, we adopt a precision intervention framework distinguishing two strategies: functional decoupling, which separates beneficial from detrimental SL activities; and situational decoupling, which exploits detrimental functions in controlled contexts. We evaluate progress across parasitic weed control, abiotic stress mitigation, and agronomic trait optimization. We also identify scientific gaps and practical barriers limiting translation and critically assess emerging solutions to these barriers. By critically analyzing where decoupling works and what trade-offs limit its success, this review aims to guide sustainable implementation of SL-based technologies in agriculture. Full article

Perennial grains, such as Kernza^® (Thinopyrum intermedium) show promise in their ability to produce grain crops while withstanding drought and temperature extremes. However, Kernza establishes slowly, particularly in dry soils. Seed coat treatments that retain water around the germinating seed (superabsorbent polymers, or SAPs) or assist water uptake in the seedling (arbuscular mycorrhizal fungi, or AMF) could improve Kernza establishment. We conducted a greenhouse study to test the efficacy of two SAPs, one AMF inoculant (Rhizophagus intraradices), and each SAP × AMF combination as seed coats, on Kernza germination and growth under well-watered versus drought conditions. Two AMF treatments had higher proportion emergence under drought conditions than non-drought. Aboveground seedling biomass was significantly lower in four of the five seed coat treatments compared to their non-drought counterparts, but control plants did not exhibit this size reduction. Plant root colonization by AMF increased in all non-drought treatments regardless of seed coat treatment. Contrary to expectations, both SAPs tested did not improve germination and actually hindered growth under drought conditions. The AMF inoculant sometimes improved germination, but not seedling development. Future research on improving Kernza seed establishment should target more species-specific AMF inoculants or nutrient supplements as seed coats, rather than SAPs. Full article

The intensive use of chemical fertilisers has reduced nutrient uptake efficiency in plants, mainly due to salinisation. This effect has prompted the investigation of alternative forms of plant nutrient management. One of the promising solutions to this is the use of microbial inoculants, specifically arbuscular mycorrhizal fungi and the plant growth-promoting rhizobacteria (PGPR). This systematic review, conducted in accordance with PRISMA 2020 guidelines, analysed 36 peer-reviewed studies published between 2008 and 2025 across 18 countries to assess the effects of inoculation with arbuscular mycorrhizal fungi (AMF), both alone and in combination with plant growth-promoting rhizobacteria (PGPR), on maize growth, physiology, and biochemical responses. The main finding was that soil P availability was the primary factor determining whether inoculation was successful. This was especially noted in soils with soil-available P of less than 17 mg P kg⁻¹ of soil. Soil texture and pH also played key roles in both single AMF inoculation and dual AMF-PGPR inoculation. Several studies showed that dual inoculation improved maize stress tolerance by coordinating antioxidant activity, osmotic balance, and hormonal signalling, rather than through simple additive growth effects. Overall, the findings suggest that AMF-based inoculation is most effective when applied strategically in reduced-input, phosphorus-limited, or drought-prone maize systems, rather than as a universal solution. These results support targeting inoculation toward resource-constrained systems where returns are most likely, especially P-deficient soils. Full article

This study examined the influence of arbuscular mycorrhizal fungi (AMF) on root system development of the invasive Nicotiana glauca Graham (Solanaceae) under intraspecific competition. Seedlings were grown with or without AMF inoculation at four planting densities (1–4 plants per pot) in a factorial experiment arranged in a completely randomized design under greenhouse conditions. After six months, shoot and root fresh and dry biomass were measured, along with root-to-shoot ratio. Root morphological traits, including total root length, surface area, volume, mean diameter, and number of root tips, were quantified and further analyzed across five levels of root diameter (0–1 mm at 1 mm intervals). Root nitrogen, phosphorus and potassium content, AMF colonization, and spore density were also assessed. Results showed that all measured traits of non-mycorrhizal seedlings declined markedly with increasing plant density. In contrast, AMF-inoculated seedlings maintained higher root biomass, total root length, surface area, and root tip numbers, particularly at low density. Across all treatments, roots < 1 mm contributed the highest proportion of total root length, surface area, and tip number, with AMF significantly enhancing these fine-root traits. Mycorrhizal seedlings also exhibited higher root-to-shoot ratios and improved N, P, and K content compared to non-inoculated controls. Multivariate analyses further indicated that AMF inoculation was the primary factor structuring root trait variation across planting densities. Overall, AMF inoculation promoted a finer and more extensive root system under increasing intraspecific competition, indicating a key role in enhancing resource acquisition and potentially supporting the competitive ability and invasiveness of N. glauca. Full article

Arbuscular mycorrhizal fungi (AMF) are the key symbiotic microorganisms in sandy poplar plantations, regulating vegetation restoration and nutrient cycling. This study aims to investigate the impact of biogas slurry (BS) application on the community structure of AMF in the rhizosphere soil of poplar forests, in order to support the sustainable management of the forest. This study focused on poplar plantations in the sandy areas of Northeast China. High-throughput sequencing technology was utilized to examine the community structure and diversity characteristics of AMF while measuring the physical and chemical characteristics of the soil. The application of BS increased the nutritional status of poplar rhizosphere soil and changed its physical and chemical characteristics, according to the findings. Paraglomus and Glomus dominated the AMF community. The application of BS increased the relative abundance of Glomus in the 0–20 cm and 20–40 cm soil strata. The primary determinants of changes in the dominant AMF populations of poplar were TP, AP, TN, NO₃⁻-N, and pH. To conclude, BS application together with soil depth regulates AMF community composition within sandy poplar plantations. BS amendment ameliorates soil nutrient conditions, increasing subsurface AMF diversity and the relative abundance of vital functional genera. Three core hypotheses were tested: (1) BS application elevates soil carbon, nitrogen and phosphorus concentrations. (2) Biogas slurry and soil depth jointly alter AMF richness and composition. (3) BS-induced shifts in soil nutrients are significantly correlated with AMF community assemblage. Full article

Eucalyptus is an important timber species characterized by strong adaptability and rapid growth. However, adverse environmental conditions such as drought stress severely impact its growth and productivity. Arbuscular mycorrhizal (AM) fungi form beneficial symbiotic relationships with Eucalyptus root systems and significantly enhance plant stress tolerance. In this study, we identified 111 WRKY genes in Eucalyptus grandis and systematically characterized their physicochemical properties, phylogenetic relationships, gene structures, conserved motifs, synteny, and cis-acting elements. Notably, AM fungal symbiosis significantly enhanced the biomass, plant height, and root length of E. grandis seedlings under drought stress. Through integrated RNA-seq and qRT-PCR analyses, we identified 12 EgWRKY genes that responded to drought stress during AM fungal symbiosis, with their expression levels significantly elevated in AM-inoculated roots under drought conditions. These findings provide novel insights into the regulatory roles of EgWRKY genes in AM-mediated drought tolerance and establish a foundation for understanding the molecular mechanisms underlying WRKY-mediated stress responses in E. grandis. Full article

Sorghum bicolor is an important cereal crop because of its tolerance to drought, high temperature, and low input requirements. However, the low productivity of sorghum is still due to the inadequate nutrient status and inappropriate use of nitrogen (N), phosphorus (P), and potassium (K). These nutrients are essential for plant growth, metabolism, abiotic stress tolerance, and yield development. Nutrient uptake in sorghum is regulated by the plant, the rhizosphere microbiome, and close interactions between the root system and membrane-localized transporter systems. This review summarizes the molecular interaction between the root and microbes that control the N, P, and K transporter genes in sorghum. It initially describes the architecture of sorghum roots, root exudation, and the key elements that govern rhizosphere microbiome assembly. It goes on to explain the molecular structure of significant nutrient transport systems, such as nitrate, ammonium, phosphate, and potassium transporters. Other important microbial groups related to nutrient uptake identified include diazotrophs, phosphate-solubilizing, potassium-mobilizing, and arbuscular mycorrhizal fungi. The focus is specifically on the interaction of plants and microbes that affect transporter gene expression and symbiotic acquisition of nutrients. In general, the review highlights an integrated framework of the interaction of root characteristics, microbial communities, and transporter networks in the process of controlling nutrient uptake in sorghum, and it determines valuable directions for future studies and crop enhancement. Full article