Search Results (234)

Plant growth-promoting (PGP) bacteria are beneficial microbes that can help plants mitigate various biotic and abiotic stresses through different PGP functions. Flavins (FLs) are involved in flavoprotein-mediated reactions essential for plant metabolism and could act as PGP molecules. The aim of this study was to isolate and characterize potential FLs secreting bacteria from apple (Malus domestica [Suckow] Borkh) roots based on their fluorescence and to evaluate their PGP properties, including FLs secretion. A total of 26 bacteria with increased fluorescence in liquid culture were isolated from the apple roots. Based on 16S rRNA sequencing analysis, 11 genetically different strains mostly from Burkholderia and Rhizobia spp. were identified. All isolates secreted considerable amounts of riboflavin. In vitro plant assays showed that under nitrogen (N) limitation, inoculated alfalfa (Medicago sativa) plants yielded at least 25% more dry mass than non-inoculated plants, and inoculation with AK7 and FL112 enriched plant tissue N content compared to non-inoculated plants. This improved N acquisition was not linked to symbiotic N fixation. Additionally, the isolates exhibited some other PGP properties. However, no specific PGP functions were linked to improved plant N acquisition but could potentially be linked to the FLs secretion. For future investigation, the mechanisms underlying improved plant N uptake should be assessed to gain a more in-depth understanding. Full article

To elucidate the potential of integrated multi-omics approaches for studying systemic mechanisms of mycorrhizal fungi in mediating plant-microbe interactions, this study employed the Tuber-inoculated Corylus system as a model to demonstrate how high-throughput profiling can investigate how fungal inoculation reshapes the rhizosphere microbial community and correlates with host metabolism. A pot experiment was conducted comparing inoculated (CTG) and non-inoculated (CK) plants, followed by integrated multi-omics analysis involving high-throughput sequencing (16S/ITS), functional prediction (PICRUSt2/FUNGuild), and metabolomics (UPLC-MS/MS). The results demonstrated that inoculation significantly restructured the fungal community, establishing Tuber as a dominant symbiotic guild and effectively suppressing pathogenic fungi. Although bacterial alpha diversity remained stable, the functional profile shifted markedly toward symbiotic support, including antibiotic biosynthesis and environmental adaptation. Concurrently, root metabolic reprogramming occurred, characterized by upregulation of strigolactones and downregulation of gibberellin A5, suggesting a potential “symbiosis-priority” strategy wherein carbon allocation shifted from structural growth to energy storage, and plant defense transitioned from broad-spectrum resistance to targeted regulation. Multi-omics correlation analysis further revealed notable associations between microbial communities and root metabolites, proposing a model in which Tuber acts as a core regulator that collaborates with the host to assemble a complementary micro-ecosystem. In summary, the integrated approach successfully captured multi-level changes, suggesting that Tuber-Corylus symbiosis constitutes a fungus-driven process that transforms the rhizosphere from a competitive state into a mutualistic state, thereby illustrating the role of mycorrhizal fungi as “ecosystem engineers” and providing a methodological framework for green agriculture research. Full article

Host odour may be affected by symbiotic microbes that produce metabolites. As a result, chemical signal production may be influenced. Few studies to date have assessed how symbiotic microbes influence variation in geography of animal chemical signals. This is important because chemical signal divergence can affect mate choice, species recognition, and ultimately speciation in a broad range of animals. However, the underlying driving forces of chemical signal divergence are still rather poorly understood. To study chemical signals, bats provide a good model system because they are such social mammals. Because males roost in dark spaces during the daytime, they rely on chemical and acoustic signals. We identified three colonies across a large geographic area and collected male forehead gland secretions from Pratt’s leaf-nosed bats (Hipposideros pratti). We examined the role symbiotic microbes played in potential variation in the geography of chemical signals. We observed significant colony-level differences in compound categories and in the amount of specific compounds. We also found significant colony-level differences in forehead gland microbiota. However, there was no significant relationship between bat-gland bacterial community composition and variation in chemical composition across colonies. These results suggest that bacterial communities may fail to shape the chemical signalling profiles of the different colonies in Pratt’s leaf-nosed bats. Full article

Lima bean (Phaseolus lunatus L.), an important legume in semiarid environments, often exhibits low yield, requiring strategies to enhance symbiotic nitrogen fixation and nutrient-use efficiency. This study evaluated the effects of single and combined inoculation with Bradyrhizobium elkanii (strain BR 2003) and Azospirillum brasilense (strain Ab-V5) on nitrogen metabolism, nutrient uptake, plant growth, and residual soil fertility in P. lunatus. Four varieties were subjected to four treatments: control (nitrogen fertilization), single inoculation with B. elkanii or A. brasilense, and co-inoculation. All inoculation strategies significantly increased root nodulation, nitrogen assimilation, and the accumulation of key macronutrients. Root nodulation increased from 1 to 12 nodules per plant in the control treatments to up to 277 nodules per plant under inoculation, while shoot nitrogen content increased by up to 91% in ‘Raio de Sol’ and 87% in ‘Cearense’. Increases in P and K were also observed, including a 48% increase in shoot P in ‘Manteiga’ and up to a 100% increase in shoot K in ‘Raio de Sol’, whereas root K increased by up to 90% under co-inoculation. The ‘Raio de Sol’ and ‘Manteiga’ varieties exhibited the most pronounced increases in growth and biomass. Additionally, inoculation improved post-cultivation soil indicators, including pH and available P and K in specific genotype-microbe combinations, and reduced electrical conductivity. These results demonstrate the strong contribution of microbial inoculation to nitrogen assimilation and nutrient acquisition, supporting its use as a promising alternative to conventional nitrogen fertilization in lima bean cultivation. Full article

Marine natural products (MNPs) are a diverse group of bioactive compounds with varied chemical structures, but their biological origins are often misannotated due to complex host–microbe symbiosis. Propagated through public databases, such errors hinder biosynthetic studies and AI-driven drug discovery. Here, we develop a structure-based workflow of origin classification and misannotation correction for marine datasets. Using CMNPD and NPAtlas compounds, we integrate a two-step cleaning strategy that detects label inconsistencies and filters structural outliers with a microbial-pretrained graph neural network. The optimized model achieves a balanced accuracy of 85.56% and identifies 3996 compounds whose predicted microbial origins contradict their Animalia labels. These putative symbiotic metabolites cluster within known high-risk taxa, and interpretability analysis reveal biologically coherent structural patterns. This framework provides a scalable quality-control approach for natural product databases and supports more accurate biosynthetic gene cluster (BGC) tracing, host selection, and AI-driven marine natural product discovery. Full article

Vectoring tomato spotted wilt virus (TSWV) by two well-known thrips species, Frankliniella occidentalis Pergande and F. intonsa Trybom (Thysanoptera: Thripidae), is facilitated in different ways. Symbiotic bacteria positively influence thrips fitness, but the interaction between these bacteria and tospovirus inside the thrips’ body remains unknown. Metagenomic profiling of symbionts in nonviruliferous and viruliferous Frankliniella thrips was performed to elucidate the interactions between symbiotic bacteria and the virus. A total of 97 operational taxonomic units (OTUs) were identified by profiling the microbes, where Proteobacteria was the most abundant phylum, with a high richness in Serratia spp. F. occidentalis showed lower variation in bacterial diversity between nonviruliferous and viruliferous treatments than F. intonsa. RT-qPCR validation for Serratia and Escherichia revealed opposite abundance patterns between the two thrips species. In contrast, Enterobacteriaceae and Pantoea showed similar patterns with higher abundance in nonviruliferous conditions. Wolbachia was detected exclusively in F. intonsa, with a higher bacterial titer in the viruliferous sample. Our findings suggest that TSWV association may influence the abundance of different bacterial symbionts within the thrips’ body, potentially via induction of antimicrobial peptides in response to viral invasion, and to our knowledge this is the first report addressing this tripartite interaction. These findings improve our understanding of how virus–symbiont association contributes to thrips vector competence. Full article

Microbe–plant interactions are a cornerstone of sustainable agriculture, offering eco-friendly alternatives to synthetic fertilizers and pesticides. These benefits are not cost-free for the host, and maintaining mutualisms requires investments of carbon, ATP, macro- and micro-nutrients, and water. Many associations involve the formation of specialized symbiotic tissues and depend on extensive signaling and immune modulation to sustain compatibility. In this review, we synthesize current knowledge on plant–microbe interactions that enhance crop performance and evaluate the accompanying costs, framing them as a physiological and ecological trade-off. Full article

Grassland ecosystems play a key role in global carbon and nutrient cycling, yet their productivity is increasingly affected by changing climate, land use, and nutrient inputs. Recent studies have identified plant–microbe interactions as a crucial biological mechanism regulating these changes. However, comprehensive research across different biomes remains insufficient. This review focuses on the functional characteristics and physiological processes of microorganisms to explore how they influence grassland productivity and stability in the context of global change, and proposes quantifiable indicators to improve model predictions. By integrating evidence from alpine, temperate, and arid grasslands, we summarize how microbial carbon use efficiency(CUE), nutrient cycling enzyme activity, and symbiotic capabilities affect plant nutrient acquisition, carbon allocation, and stress resistance. Meta-analytical data indicate that microbial processes can explain a substantial proportion of productivity variation beyond climatic and edaphic factors. We further outline methodological progress in linking molecular mechanisms with ecosystem dynamics through multi-omics, stable isotope tracing, and structural equation modeling. This synthesis highlights that incorporating microbial mechanisms into grassland productivity frameworks enhances predictive accuracy and provides an empirical basis for sustainable management. Across global grasslands, microbial processes account for roughly 40–50% of the explained variance in productivity beyond abiotic drivers, underscoring their predictive value in ecosystem models. Thes study underscores the broader significance of recognizing soil microbes as active drivers of ecosystem function, offering a biological foundation for carbon sequestration and grassland restoration strategies under global environmental change. Full article

It is inevitable for life on earth to be exposed to various types of ionizing and non-ionizing radiation, underscoring the importance of radioprotection. The symbiotic interaction between gut microbiota and the host provides a strategy for protecting the organism against these stressors. However, the genetic mechanisms underlying this interaction remain poorly understood due to the complexity and diversity of gut microbiota. In this study, we employed a symbiotic experimental system involving Caenorhabditis elegans and Escherichia coli to systemically investigate the effects of bacterial genetic alterations on host responses to radiation exposure. Our findings revealed that deletion of the bacterial ybfQ gene (ΔybfQ) significantly enhanced worm tolerance to UV-B radiation. Transcriptomic analysis demonstrated an enhanced antioxidant capacity in ΔybfQ-fed worms, as evidenced by reduced levels of reactive oxygen species (ROS) and restored oxidative homeostasis. Notably, ΔybfQ bacteria exhibited overproduction of isoscoparin, and exogenous supplementation with isoscoparin similarly enhanced worm radio-tolerance, underscoring its crucial role in ΔybfQ-mediated antioxidant of host worm. Both interventions retained their protective effects in IIS-deficient worms (daf-16). However, the protective effects of ΔybfQ feeding, but not isoscoparin treatment, were attenuated in daf-2 worms with a constitutively activated IIS pathway, accompanied by reduced bacteria gut colonization. Collectively, our results provide novel insights into the genetic basis of host-microbe interactions and propose a potential pharmacological strategy for radiation protection. Full article

Deep-sea mussels of the genus Bathymodiolus exhibit adaptability to nutrient-poor deep-sea environments by establishing nutritional intracellular symbiosis with chemosynthetic bacteria harbored within the gill epithelial cells. However, this poses a conflict for the innate immune system of the host, which must balance the tolerance of beneficial symbiotic bacteria with the need to eliminate exogenous microbes. This review synthesizes existing knowledge and recent findings on Bathymodiolus japonicus to outline the cellular and molecular mechanisms governing this symbiotic relationship. In the host immune system, hemocytes are responsible for systemic defense, whereas gill cells are involved in local symbiotic acceptance. Central to the establishment of symbiosis is the host’s phagocytic system, which non-selectively engulfs bacteria but selectively retains symbionts. We highlight a series of cellular events in gill cells involving the engulfment, selection, retention and/or digestion of symbionts, and the regulatory mechanism of phagocytosis through mechanistic target of rapamycin complex 1, which connects bacterial nutrient supply with host immune and metabolic responses. This integrated model of symbiosis regulation, which links immunity, metabolism, and symbiosis, provides a fundamental framework for understanding how hosts establish and maintain a stable coexistence with microbes, offering a new perspective on symbiotic strategies in diverse organisms. Full article

Plasmodesmata (PD) are dynamic nanochannels interconnecting plant cells and coordinating development, nutrient distribution, and systemic defense. Their permeability is tightly regulated by callose turnover, PD-localized proteins, lipid microdomains, and endoplasmic reticulum (ER)–plasma membrane (PM) tethers, which together form regulatory nodes that gate symplastic exchange. Increasing evidence demonstrates that effectors from diverse kingdoms—fungi, oomycetes, bacteria, viruses, viroids, phytoplasmas, nematodes, insects, parasitic plants, and symbiotic microbes—converge on these same nodes to modulate PD gating. Pathogens typically suppress callose deposition or destabilize PD regulators to keep channels open, whereas mutualists fine-tune PD conductivity to balance resource exchange with host immunity. This review synthesizes current knowledge of effector strategies that remodel PD architecture or exploit PD for intercellular movement, highlighting novel cross-kingdom commonalities–callose manipulation, reprogramming of PD proteins, lipid rewiring, and co-option of ER-PM tethers. We outline unresolved questions on effector–PD target specificity and dynamics, and identify prospects in imaging, proteomics, and synthetic control of PD. Understanding how effectors reprogram PD connectivity can enable engineering of crops that block pathogenic trafficking while safeguarding beneficial symbioses. Full article

Seed-related traits such as seed size, germination, vigour, dormancy, biochemical composition, and stress resistance are critical to ensuring agricultural productivity and global food security, particularly in current scenarios of climate change and environmental unpredictability. This review examines the transformative potential of omics technologies, encompassing genomics, transcriptomics, proteomics, metabolomics, epigenomics, and phenomics, in enhancing our understanding of seed biology and its applications in crop improvement. Genomics and transcriptomics are key technologies in future plant breeding and gene editing to optimise seed yield and quality. We reviewed the role of metabolomic approaches in uncovering the molecular mechanisms behind seed germination, vigour, dormancy, and the proteomic advances to elucidate markers of seed quality, combining these omic technologies to decipher DOG1 as a marker of dormancy. Both biotic and abiotic stress resistance in seeds were reviewed from a multi-omics perspective to determine the best avenues for improving the resilience of seeds against drought, salinity and pathogens. Moreover, omics approaches have been reviewed to optimise plant–microbe interactions, particularly in enhancing symbiotic relationships within the soil microbiome. Full article

The sycamore lace bug Corythucha ciliata (Hemiptera: Tingidae), an invasive North American forest pest, owes its strong dispersal and adaptability to biological characteristics and symbiotic microbes, but the underlying mechanisms have not been fully elucidated. This study examined its outdoor-collected (LYGO) and indoor-reared (LYGI) populations using morphological observation, biological parameter assessment, and 16S rRNA sequencing. Key findings include: (1) Nymphs develop through five instars, with body size increasing significantly across stages; growth accelerated during 4th and 5th instars, reflecting a pattern of “low-instar accumulation and high-instar acceleration”. (2) Adult survival differed by sex, with females outliving males after 30 days; nymphs develop in 14.81 days, and each adult pair produced an average of 17 eggs, demonstrating a concentrated reproductive strategy; (3) Both populations shared dominant bacterial taxa (including the phyla Bacteroidota and Proteobacteria and the genus Cardinium) but diverged in non-dominant taxa; core microbial functions were conserved, while specific functions (e.g., glutathione S-transferase activity) varied. These results suggest a potential synergy between the insect’s biological characteristics (efficient development, concentrated reproduction) and the adaptive functions of its associated microbes in enhancing its invasiveness. The study supplements its basic biological data and offers a new view of its ecological adaptability. Full article

Dendroctonus armandi is a native bark beetle that infests healthy Pinus armandii Franch. in western China. The complex symbiotic relationships with diverse microbes are critical to hosts for survival and outbreak dynamics. Understanding the potential functions and assembly metabolisms of these symbiotic microbes to host colonization are therefore crucial. Metagenomic analysis revealed that gut microbial communities differed from cuticular ones significantly. The cuticle exhibited greater fungal diversity, while the gut supported a significantly higher bacterial diversity. Our findings indicated that gut unclassified Burkholderiales, Escherichia, Bacteroides and Prevotella may play a crucial role in degrading terpenes, phenols and polysaccharides rather than cuticular microbes. Stochastic processes appeared to be served as the primary drivers shaping the core microbial community structures. Cuticular dominant and functional microbial community assemblies except for Escherichia may be primarily driven by stochasticity to adapt the unstable habitats. The direct comparison of gut and cuticular microbiomes may provide valuable insights into the specific functions of symbiotic microbes, and offer critical molecular data for broader understanding of symbiotic relationship between bark beetles and microbes. Full article

Herbivorous animals rely on complex gastrointestinal systems and microbial communities to efficiently digest plant-based diets, extract nutrients, and maintain health. Recent advances in metagenomic technologies have enabled high-resolution, culture-independent analysis of gut microbiota composition, functional potential, and host–microbe interactions, providing insights into microbial diversity across the herbivore digestive tract. This review summarizes key findings on the gastrointestinal microbiota of herbivores, focusing on ruminant foregut and non-ruminant hindgut fermentation. Ruminants like cattle, sheep, and goats host microbiota enriched with fibrolytic and methanogenic microbes that facilitate fiber degradation and volatile fatty acid production, contributing significantly to energy balance. In contrast, non-ruminants such as horses and rabbits rely on hindgut fermentation, with distinct microbial taxa contributing to carbohydrate and protein breakdown. The review further explores how specific microbial taxa, including Prevotella, Fibrobacter, and Ruminococcus, correlate with improved feed efficiency and growth performance, particularly in ruminants. Additionally, the roles of probiotics, prebiotics, and symbiotics in modulating gut microbial composition and enhancing productivity are discussed. Despite significant advances, challenges remain in microbial sampling, functional annotation, and understanding the integration of microbiota with host physiology. The review emphasizes the potential of metagenomic insights in optimizing herbivore gut microbiota to improve feed efficiency, health, and sustainable livestock production. Full article