Search Results (147)

Ericoid mycorrhizal fungi (EMF) enhance plant fitness and metabolic regulations in nutrient-poor soils, though the mechanisms diving these interactions require further elucidation. This study investigated the physiological and metabolic responses of blueberry seedlings following 2- and 3-weeks inoculation with Oidiodendron maius H14. The results indicated that EMF could significantly increases plant biomass, improve the accumulation of osmoregulatory substances in leaves. Additionally, the colonization rate of EMF are 26.18% and 30.22% after 2- and 3-weeks, respectively. The Metabolomics analysis identified 758 (593 up- and 165 down-regulated) and 805 (577 up- and 228 down-regulated) differential metabolites in roots at 2- and 3-weeks inoculation with O. maius H14, respectively. KEGG pathway annotation revealed that O. maius H14 triggered various amino acid metabolism pathways, including tryptophan metabolism and arginine and proline metabolism. These findings suggested that O. maius H14 stimulated root-specific biosynthesis of growth-promoting compounds and antimicrobial compounds. Concomitant downregulation of stress-associated genes and upregulation of glutamine synthetase suggest EMF modulates host defense responses to facilitate symbiosis. Thus, our results demonstrated that O. maius H14 orchestrates a metabolic reprogramming in blueberry roots, enhancing growth and stress tolerance through coordinated changes in primary and specialized metabolism, which could inform strategies for improving symbiosis and metabolic engineering in horticultural practices. Full article

Xenorhabdus species are entomopathogenic bacteria that live in symbiosis with Steinernema nematodes and produce a wide range of bioactive secondary metabolites. This study aimed to characterize the complete genomes and biosynthetic potential of two novel Xenorhabdus isolates, ALN7.1 and ALN11.5, recovered from Steinernema lamjungense collected in Northern Thailand. High-quality genome assemblies were generated, and phylogenomic comparisons confirmed that both isolates belonged to the recently described species Xenorhabdus thailandensis. The assembled genomes were approximately 4.02 Mb in size, each comprising a single circular chromosome with a GC content of 44.6% and encoding ~3800 protein-coding sequences, consistent with the features observed in other members of the genus. Biosynthetic gene cluster (BGCs) prediction using antiSMASH identified 19 BGCs in ALN7.1 and 18 in ALN11.5, including known clusters for holomycin, pyrrolizixenamide, hydrogen cyanide, and gamexpeptide C, along with several uncharacterized clusters, suggesting unexplored metabolic potential. Comparative analyses highlighted conserved yet strain-specific BGC profiles, indicating possible diversification within the species. These results provide genomic insights into X. thailandensis ALN7.1 and ALN11.5 and support their potential as valuable sources for the discovery of novel natural products and for future biotechnological applications. Full article

Insect pests inflict significant agricultural and economic losses on crops globally. Chemical control refers to the use of agrochemicals, such as insecticides, herbicides, and fungicides, to manage pests and diseases. Chemical control is still the prioritized method, as insecticides are highly effective and toxic to insect pests. However, it reduces the quality of the environment, threatens human health, and causes serious 3R (reduce, reuse, and recycle) problems. Current advances in the mining of functional symbiotic bacteria resources provide the potential to assuage the use of insecticides while maintaining an acceptably low level of crop damage. Recent research on insect–microbe symbiosis has uncovered a mechanism labeled “detoxifying symbiosis”, where symbiotic microorganisms increase host insect resistance through the metabolism of toxins. In addition, the physiological compensation effect caused by insect resistance affects the ability of the host to regulate the community composition of symbiotic bacteria. This paper reviews the relationship between symbiotic bacteria, insects, and insecticide resistance, focusing on the effects of insecticide resistance on the composition of symbiotic bacteria and the role of symbiotic bacteria in the formation of resistance. The functional symbiotic bacteria resources and their mechanisms of action need to be further explored in the future so as to provide theoretical support for the development of pest control strategies based on microbial regulation. Full article

Despite chemical exchange often serving as the first step in plant–microbe interactions, the specialized chemical metabolites produced by grass–Epichloë endophyte symbiosis as mediators of host growth, nutrient acquisition, and modulators of the rhizosphere community under low-nitrogen conditions are areas lacking in knowledge. In this study, we investigated the plant growth-promoting effects of the Epichloë endophyte strain and identified the growth of the Epichloë strain under different types of nitrogen source treatments. In addition to the in vitro test, we evaluated growth performance for Epichloë endophyte–infected plants (E+) and Epichloë endophyte–free plants (E−) in a pot trial under 0.01 mol/L urea treatment. Seedlings from E+ and E− groups were collected to analyze the plant bacterial microbiome and root metabolites. The E. gansuensis endophyte strain was found not to produce indoleacetic acid (IAA), pectinase, or contain ferritin. The nitrogenase gene, essential for nitrogen fixation, was also absent. These results suggest that E. gansuensis endophyte strains themselves do not contain attributes to promote plant growth. Concerning N fertilization, it was observed an increase in the colony diameter of E. gansuensis strain was observed only in the NO₃⁻-N (NN) treatment, while inhibition was observed in the urea-N (UN) treatment. E. gansuensis endophyte symbiosis significantly increased tiller number and plant dry weight. Overall, our results suggest that the E+ plants had more root forks and greater average root diameter compared to E− plants under the UN treatment. In a pot experiment using UN, data from 16S rRNA amplicon sequencing revealed that E. gansuensis endophyte infection significantly altered the bacterial community composition in shoot and root, and significantly increased Shannon (p < 0.001) and Chao 1 (p < 0.01) indexes. The relative abundance of Acidobacteriota, Actinomycetota, Cyanobacteriota, Fibrobacterota, Myxococcota, and Patescibacteria in the shoot, and Cyanobacteriota, Pseudomonadota, and Verrucomicrobiota in the root were significantly increased by E. gansuensis endophyte infection. Similarly, E. gansuensis endophyte symbiosis shifted the metabolite composition of the host plants, with the E+ plants showing a higher number of metabolites than the E− plants. In addition, co-metabolism network analysis revealed that the positive relevance between exudates and microorganisms in the root of the E+ plants is higher than that of the E− plants. These findings provide valuable insights into the knowledge of the effects of the symbiotic relationship between host plants and Epichloë endophyte on interspecific interactions of plant microbiome, beneficial for harnessing endophytic symbiosis, promoting plant growth. Full article

Salt accumulation in arable lands causes significant abiotic stress, resulting in a 10% loss in global arable land area and jeopardizing food production and agricultural sustainability. In order to attain high and sustainable food production, it is imperative to enhance traditional agricultural practices with modern technology to enable the restoration of arable lands afflicted by salinity. This review consolidates recent rice-specific advancements aimed at enhancing salt stress resilience through integrated strategies. We explore the functions of primary and secondary metabolic pathways, organic amendments, microbial symbiosis, and plant growth regulators in reducing the negative impacts of salt. Furthermore, we highlight the significance of emerging genetic and epigenetic technologies, including gene editing and transcriptional regulation, in developing salt-tolerant rice cultivars. Physiological studies reveal salt stress responses in rice plants, biochemical analyses identify stress-related metabolites, microbial investigations uncover beneficial plant–microbe interactions, and molecular approaches enable the identification of key genes—together providing essential insights for developing salt-tolerant rice varieties. We present a comprehensive overview of the multilayered strategies—ranging from agronomic management and physiological adaptations to molecular breeding and microbial applications—that have been developed and refined over recent decades. These approaches have significantly contributed to understanding and improving salinity tolerance mechanisms in rice. This review provides a foundational framework for future research and practical implementation in stress-resilient rice farming systems. Full article

Cerium dioxide nanoparticles (CeO₂-NPs) are increasingly used in various industrial applications, leading to their inevitable release into the environment including the soil ecosystem. In soil, CeO₂-NPs are taken up by plants, translocated, and accumulated in plant tissues. Within plant tissues, CeO₂-NPs have been shown to interfere with critical metabolic pathways, which may affect plant health and productivity. Moreover, their presence in soil can influence soil physico-chemical and biological properties, including microbial communities within the rhizosphere, where they can alter microbial physiology, diversity, and enzymatic activities. These interactions raise concerns about the potential disruption of plant–microbe symbiosis essential for plant nutrition and soil health. Despite these challenges, CeO₂-NPs hold potential as tools for enhancing crop productivity and resilience to stress, such as drought or heavy metal contamination. However, understanding the balance between their beneficial and harmful effects is crucial for their safe application in agriculture. To date, the overall impact of CeO₂-NPs on soil -plant system and the underlying mechanism remains unclear. Therefore, this review analyses the recent research findings to provide a comprehensive understanding of the fate of CeO₂-NPs in soil–plant systems and the implications for soil health, plant growth, and agricultural productivity. As the current research is limited by inconsistent findings, often due to variations in experimental conditions, it is essential to study CeO₂-NPs under more ecologically relevant settings. This review further emphasizes the need for future research to assess the long-term environmental impacts of CeO₂-NPs in soil–plant systems and to develop guidelines for their responsible use in sustainable agriculture. Full article

In this study, the migratory agricultural pest Spodoptera frugiperda was exposed to three periodic short-term heat stress regimes at 37 °C, 40 °C, and 43 °C (2 h daily), with a constant 26 °C control. We systematically evaluated the effects of periodic thermal stress on developmental traits across all life stages. Combined with 16S rRNA high-throughput sequencing, we analyzed the structural and functional characteristics of the gut bacterial community in adults under heat stress. The results demonstrated that 37 °C exposure accelerated egg-to-adult development, whereas 43 °C markedly extended it. Additionally, 43 °C heat stress suppressed pupation and eclosion rates. Increasing stress temperatures were negatively correlated with pupal weight and body size in both sexes. Notably, 43 °C heat stress caused complete loss of hatching ability in offspring eggs, thereby rendering population reproduction unattainable. 16S rRNA sequencing revealed that Proteobacteria (>90%) dominated the gut bacterial community at the phylum level across all treatments. Under 43 °C heat stress, although female and male adults exhibited an increase in specific bacterial species within their gut bacteria, Alpha diversity analysis revealed no significant differences in the diversity (Shannon index) and richness (Chao index) of gut bacterial communities between sexes under temperature treatments. PICRUSt2 functional prediction indicated that metabolic pathways, biosynthesis of secondary metabolites, and microbial metabolism in diverse environments constituted the dominant functions of gut bacteria in both sexes, while heat stress exerted minimal effects on the functional profiles of gut bacteria in S. frugiperda. These findings not only provide a theoretical basis for predicting summer population dynamics and formulating ecological control strategies for S. frugiperda but also offer critical insights into the adaptive interactions between this pest and its gut bacterial community under heat stress. The results lay a foundation for further exploring the interactions between insect environmental adaptability and bacterial symbiosis. Full article

The genus Trichoderma comprises a group of fungi known for their beneficial effects on plant growth and stress tolerance. Light is a key environmental factor affecting many plant physiological processes. However, a significant research gap remains regarding the interaction between light quality and Trichoderma harzianum inoculation, particularly their combined effects on tomato plant growth and photosynthetic efficiency. Here, we showed that T. harzianum inoculation effectively alleviated the growth inhibition caused by monochromatic red light or blue light in tomato plants. Combined red and blue light treatment with T. harzianum inoculation (RBT) promoted root development by regulating the rational distribution of carbon assimilation products. Specifically, the RBT treatment upregulated the expression of photosynthesis-related genes, including key Calvin cycle enzyme genes such as FBPase, FBPA, TPI, and SBPase, as well as the light signal transduction factor HY5. In addition, T. harzianum inoculation increased the maximal photochemical efficiency of PSII (Fv/Fm), and the net photosynthetic rate (Pn). The activity of sucrose synthetase (SS) and sucrose phosphate synthetase (SPS) was also enhanced, promoting photosynthetic product accumulation in leaves and roots. Among all treatment groups, RBT performed the best in the above indexes. Full article

Zizania latifolia (Jiaobai) is an economically important aquatic crop characterized by unique gall formation through interaction with the smut fungus Ustilago esculenta. Understanding factors influencing this interaction is crucial for cultivation. This study investigates the non-target effects of the fungicide Fenaminosulf (FM) on Z. latifolia’s growth, physiology, and underlying molecular pathways. We demonstrate that FM exerts striking concentration-dependent effects, revealing its potential as a modulator of plant development and symbiosis. Physiological measurements showed that a moderate FM concentration (1.25 g/L) promoted key vegetative growth parameters, including plant height and leaf length, while maintaining chlorophyll content, suggesting a potential bio-stimulant effect. In contrast, higher FM concentrations (2.5 g/L and 5 g/L) inhibited vegetative growth but significantly enhanced gall formation, particularly at 2.5 g/L, indicating that FM can redirect plant resources or alter susceptibility to favor the fungal interaction under specific conditions. Transcriptomic analysis provided mechanistic insights, revealing extensive gene expression reprogramming, especially under high FM treatment (5 g/L). Key pathways related to plant-pathogen interaction, phenylpropanoid biosynthesis, and hormone signal transduction were significantly modulated. Notably, FM treatment suppressed key immune-related genes, including Xa21 and PBL19, potentially reducing plant resistance and facilitating gall formation. Hormone signaling analysis revealed inhibition of auxin, cytokinin, brassinosteroid, and jasmonic acid metabolism, indicating a comprehensive molecular recalibration of plant developmental processes. The study provides novel insights into the molecular mechanisms by which FM influences Z. latifolia growth and gall formation. The concentration-dependent effects of FM suggest its potential as a strategic tool for agricultural management, offering a nuanced approach to crop development. These findings contribute to understanding plant-chemical interactions and provide valuable directions for optimizing Z. latifolia cultivation strategies. Full article

Peanut (Arachis hypogaea L.) is one of the most important oilseeds crops worldwide. Through symbiosis with the bacterium Bradyrhizobium sp., peanuts can assimilate atmospheric nitrogen, reducing the need for chemical fertilizers. However, this nitrogen fixation process is highly sensitive to environmental factors that can inhibit the early stages of symbiotic interaction. In this study, we propose the encapsulation of Bradyrhizobium sp. SEMIA6144 and the flavonoid naringin (Nar) in alginate beads to improve flavonoid stability and promote nodulation kinetics in peanuts. Three types of beads were synthesized: A (control, SEMIA6144 only); B (SEMIA6144 induced with 10 µM Nar); and C (SEMIA6144 co-entrapped with 1 mM Nar). Although Nar increased cell mortality (2-fold compared to control) and reduced metabolic activity—particularly at 1 mM—cells in beads B and C responded by altering their membrane fatty acid profile (30% and 55.5% of 18:1, respectively) leading to a reduction in saturated fatty acids (5.8% and 13.1% for 16:0 and 18:0 in B; 11.8% and 21.2% in C). Bacterial release kinetics followed a primarily Fickian diffusion model, with minor matrix–bacteria interactions in Nar-treated beads. Notably, bacterial release in peanut root exudates was 6%, 10%, and 11% higher for beads A, B, and C, respectively, compared to release in physiological solutions. Nar-beads enhanced the formation of curved root hairs, promoted bacterial colonization in root hair zones, and stimulated the appearance of rosette-like structures associated with nodule initiation. In conclusion, encapsulating Bradyrhizobium sp. SEMIA6144 with Nar in beads represents a promising strategy to improve symbiotic nitrogen fixation in peanuts. Full article

Precision nutrition-targeted gut microbiota (GM) may have therapeutic potential not only for age-related diseases but also for slowing the aging process and promoting longer healthspan. Recent studies have shown that restoring a healthy symbiosis of GM by counteracting dysbiosis (DYS) through precise nutritional intervention is becoming a major target for extending healthspan. Microbiota-accessible borate (MAB) complexes, such as boron (B)–pectins (rhamnogalacturonan–borate) and borate–phenolic esters (diester chlorogenoborate), have a significant impact on healthy host–microbiota symbiosis (HMS). The mechanism of action of MABs involves the biosynthesis of the autoinducer-2–borate (AI-2B) signaling molecule, B fortification of the mucus gel layer by the MABs diet, inhibition of pathogenic microbes, and reversal of GM DYS, strengthening the gut barrier structure, enhancing immunity, and promoting overall host health. In fact, the lack of MAB complexes in the human diet causes reduced levels of AI-2B in GM, inhibiting the Firmicutes phylum (the main butyrate-producing bacteria), with important effects on healthy HMS. It can now be argued that there is a relationship between MAB-rich intake, healthy HMS, host metabolic health, and longevity. This could influence the deployment of natural prebiotic B-based nutraceuticals targeting the colon in the future. Our review is based on the discovery that MAB diet is absolutely necessary for healthy HMS in humans, by reversing DYS and restoring eubiosis for longer healthspan. Full article

Microbial interactions are essential for maintaining the stability and functionality of microbiota in fermented foods. In this study, representative strains of predominant lactic acid bacteria and acetic acid bacteria in Sichuan bran vinegar were selected, and their interactions in a simulated solid-state fermentation system were investigated. The results reveal that the biomass of A. pasteurianus LA10 significantly increased in both the co-culture and the pure culture, whereas the biomass of L. amylovorus LL34 in the co-culture (6.44 ± 0.30 lg CFU/g) was significantly lower than that in the pure culture (7.28 ± 0.30 lg CFU/g) (p < 0.05), indicating a partially harmful symbiosis between these two strains. The metabolic analysis shows that total acid (21.82 mg/g) and acetic acid (9.53 mg/g) contents in the co-culture were lower than those in the pure culture of LA10, suggesting that LL34 inhibited the acid-producing activity of LA10 to some extent. The interaction between the two bacteria also influenced the production of volatile compounds and non-volatile compounds, as revealed by GC-MS and untargeted UHPLC-MS/MS, respectively. Significant enrichment of acid and amino acid metabolism pathways was observed in the co-culture, revealing the impact of bacterial interactions on flavor development. This study provides valuable insights into the advancement of vinegar brewing technology. Full article

Significant regional variations in seawater characteristics (temperature, salinity, pH, nutrients) exist across marine environments, yet their impacts on abalone gastrointestinal microbiota and metabolites remain underexplored. This study investigated seawater nutrient and pH interactions on abalone gut ecosystems through comparative analysis of three marine regions (Pingtan (PT), Xiapu (XP), Lianjiang (LJ)). Seawater characteristics revealed distinct patterns: LJ exhibited the lowest total phosphorus (TP: 0.12 mg/L), total nitrogen (TN: 2.8 mg/L), NH₃-N (0.05 mg/L) but the highest salinity (32.1‰) and lowest pH (7.82), while PT/XP showed elevated nutrients (TP: 0.24–0.28 mg/L; TN: 4.2–4.5 mg/L). Microbial diversity peaked in LJ samples (Shannon index: 5.8) with dominant genera Psychrilyobacter (12.4%) and Bradyrhizobium (9.1%), contrasting with PT’s Mycoplasma-enriched communities (18.7%) and XP’s Vibrio-dominant profiles (14.3%). Metabolomic analysis identified 127 differential metabolites (VIP > 1.5, p < 0.05), predominantly lipids (38%) and organic acids (27%), with pathway enrichment in sulfur relay (q = 4.2 × 10⁻⁵) and tryptophan metabolism (q = 1.8 × 10⁻⁴). Stomach-specific metabolites correlated with fatty acid degradation (e.g., inosine diphosphate, r = −0.82 with vibrionimonas) and glutathione metabolism (methionine vs. mycoplasma, r = −0.79). Critically, pH showed negative correlations with beneficial Psychrilyobacter (oleamide: r = −0.68) and positive associations with pathogenic Vibrio (trigonelline: r = 0.72). Elevated NH₃-N (>0.15 mg/L) and TP (>0.25 mg/L) promoted Mycoplasma proliferation (R² = 0.89) alongside cytotoxic metabolite accumulation. These findings demonstrate that higher pH (>8.0) and nutrient overload disrupt microbial symbiosis, favoring pathogens over beneficial taxa. Full article

Epichloë endophytic fungi are important microbial resources in agriculture and animal husbandry. Because of their stable symbiosis, species transmission, and positive effects on host plants, the use of endophytic fungi in grass breeding is of great significance. In this study, six inoculation methods were used, including the sterile seedling slit inoculation method, sterile seedling cut inoculation method, sterile seedling injection inoculation method, seed soaking inoculation method, seed piercing and then soaking inoculation method, and seed slit inoculation method. Spectrometry was used to construct new symbionts, and Liquid Chromatography–mass spectrometry was used to analyze the effects of endophytic fungi on the metabolism of new hosts. The physiological response of the new symbionts to salt and alkali stress was studied using a pot experiment. The results were as follows: In this study, Epichloë bromicola was successfully inoculated into Bromus inermis via the sterile seedling slit inoculation method, and new symbionts (EI) were obtained; the vaccination rate was 2.1%. Metabolites up-regulated by EI are significantly enriched in citrate cycle and ascorbate and aldarate metabolism, suggesting that the symbiosis of endophytic fungi indirectly triggers the production of reactive oxygen species (ROS) through multiple metabolic pathways. The saline–alkali stress test showed that the host antioxidant system was active after inoculation, and the total antioxidant capacity was significantly increased compared with non-symbionts (EF) under mild stress (p < 0.05), which provided important clues to reveal the complex mechanism of plant–fungus symbiosis. This study provides practical guidance and a theoretical basis for plant adaptation under climate change, health management of grass seeds, and soil improvement through endophytic fungi. Full article

Anaerobic digestion (AD) of high-solid mono-chicken manure (CM) holds great promise for resource utilization. However, the effects of substrate overload (high-solid mixture inside the reactor) on AD performance at various temperatures are still unclear, moreover, the metabolic processes with and without inoculation are also seldom reported. In this study, three key impact factors of different temperatures (4 °C, 35 °C, 55 °C and 75 °C), total solids (TS) inside, and inoculation were conducted to comprehensively explore the process variation. EEM-FRI results revealed that high temps boost coenzyme F_420, while TS predominately driver the microbial production. High TS and temperature synthetically result in high free ammonia (FA) (>600 mg/L) associated with free volatile fatty acid (FVFA) (>450 mg/L), reducing CH₄ production but increasing VFAs accumulation (12 g/L at 55 °C). Notably, intestinal microbiota alone without inoculation even achieved 11 g/L of VFA. The cross-feeding symbiosis between fermentative bacteria (Caldicoprobacter, Bacteroidetes, Tepidimicrobium) and hydrogenotrophic Methanobacterium enhanced CH₄ production (68 mL/gVS at 35 °C). Moreover, high temperatures reduced microbial diversity but made heat-resistant hydrolytic bacteria dominant. This study precisely analyzes the effects of temperature and inoculation factors on the acidification efficiency of high-solid CM digestion, providing a crucial scientific basis for optimizing the resource utilization of CM waste. Full article