Search Results (331)

Ticks harbor complex microbial communities composed of symbionts, commensals, and tick-borne pathogens (TBPs). Together, these microorganisms form the tick holobiont. Within this system, the tick’s physiological architecture structures microbial communities by distributing microorganisms across distinct tissues. This compartmentalization creates spatially distinct ecological niches, which in turn shape how microbial communities assemble and interact. In this review, we integrate ecological theory with current knowledge of tick microbiome research to examine how pathogen–pathogen and pathogen–microbiome interactions emerge within these tissue-structured microbial communities. We first outline how baseline ecological filters, including tick species, developmental stage, tissue identity, vertical transmission, and environmental context, shape the microbiome configuration through community assembly processes. We then examined how TBPs, as high-impact colonizers, can further modify microbial networks by altering host-mediated selective pressures, influencing interaction topology, and reshaping community stability. Based on these observations, we propose a dual selective pressure framework in which (i) baseline ecological structuring processes and (ii) pathogen-associated selective pressures interact to determine the microbial network configuration and functional outcomes within the tick holobiont. These interacting forces may drive shifts in diversity, modularity, keystone taxa emergence, and network resilience, ultimately influencing vector competence. This review frames the microbial communities within the tick holobiont as spatially structured ecological systems shaped by multilevel selective pressures. This conceptual foundation provides a coherent framework for understanding microbial interactions in arthropod vectors and highlights avenues for mechanistic research and microbiome-based strategies to mitigate tick-borne diseases. Full article

Intensive ornamental planting is increasingly prevalent in urban green spaces, yet its effects on soil microbial community assembly and interaction networks remain poorly understood. Here, we examined shifts in soil properties, microbial diversity, community composition, and interaction networks across successive planting cycles. Bacterial alpha-diversity remained relatively stable, whereas fungal communities showed pronounced sensitivity to early planting stages. Beta-diversity analyses revealed that bacterial community composition was jointly influenced by planting stage and site type, while fungal communities were primarily structured by site characteristics. Co-occurrence network analysis revealed contrasting reassembly trajectories between microbial groups. Bacterial networks exhibited increasing complexity and modularity, indicating enhanced interaction intensity and competitive structuring under intensive management. In contrast, fungal networks displayed reduced connectivity but maintained or recovered modular organization, suggesting structural buffering. Notably, keystone taxa remained taxonomically conserved, indicating that network reorganization was driven by interaction rewiring rather than species turnover. We propose a dual-speed reassembly framework in which bacteria function as fast-responding components with dynamic interaction networks, whereas fungi act as slow-buffering, structurally persistent elements. This decoupling of short-term functional responsiveness and long-term stability provides new insights into how intensive management reshapes soil microbiomes in botanical garden ecosystems. Full article

Larix olgensis, a keystone timber species in Northeast China, is increasingly threatened by Neofusicoccum laricinum-induced shoot blight, a devastating disease that compromises forest health and necessitates sustainable management strategies. Here, we demonstrate that the endophytic bacterium Bacillus amyloliquefaciens JL54 elicits multifaceted defense responses in L. olgensis, enhancing resistance to pathogen infection. Greenhouse assays revealed that JL54 pretreatment reduced disease incidence by 12.5% and achieved 43.75% control efficacy while maintaining host vigor. Histochemical analyses identified JL54-induced rapid hydrogen peroxide (H₂O₂) accumulation, extensive lignin deposition, and localized programmed cell death (PCD), indicative of a primed immune response. Transcriptomic analyses uncovered distinct temporal defense patterns: early-stage responses (0 h post-inoculation) were characterized by upregulation of cutin, suberin, and wax biosynthesis pathways, reinforcing physical barriers, whereas late-stage responses (12 h post-inoculation) were dominated by ribosome- and proteostasis-related pathways (e.g., heat shock proteins [HSPs], glutathione S-transferases [GSTs]) to mitigate cellular damage. Biochemical assays corroborated these findings, with JL54 colonization reducing membrane lipid peroxidation (27.2% decrease in malondialdehyde content) and significantly elevating the activity of key defense enzymes, including peroxidase (POD), phenylalanine ammonia-lyase (PAL), and GST. Phytohormone profiling implicated jasmonic acid (JA) as the central mediator of induced systemic resistance (ISR), with JL54-potentiated JA signaling preceding pathogen containment. Collectively, these results demonstrate that JL54 contributes to a coordinated defense strategy in L. olgensis, integrating structural reinforcement (cuticle/lignin), oxidative stress management, and JA-mediated immune priming. These insights advance the understanding of endophyte-conferred resistance in conifers and highlight JL54’s potential as a biocontrol agent for sustainable forestry. Full article

Globally, Central Asian wild fruit forests are critical repositories of wild fruit germplasm resources and provide essential ecosystem services. However, their habitats are facing escalating degradation risks driven by climate warming, shifting precipitation regimes, and intensifying anthropogenic disturbances. Accurately quantifying climate-driven spatiotemporal variations in habitat suitability for keystone wild fruit tree species is therefore an essential prerequisite for formulating targeted conservation and management strategies in arid and semi-arid landscapes. In this study, we applied the maximum entropy (MaxEnt) model to simulate the current (2000–2020 baseline) and future (2030s, 2050s, 2070s) potential suitable habitats of two dominant wild fruit tree species, Malus sieversii (Ledeb.) M.Roem. and Prunus cerasifera Ehrh., in the Ili Valley, a core distribution area of Central Asian wild fruit forests in northwestern China. We integrated rigorously screened species occurrence records with key environmental predictors and characterized future climate conditions using three Shared Socioeconomic Pathways (SSPs; SSP126, SSP245, and SSP585) spanning low to high radiative forcing levels. The model exhibited excellent predictive performance (AUC > 0.85), confirming the robustness and reliability of our habitat suitability simulations. Elevation and annual precipitation were identified as the dominant environmental variables governing habitat suitability for both species, highlighting the critical role of terrain–hydroclimate interactions in maintaining viable dryland refugia for wild fruit forests. Under the baseline climate scenario, the total area of suitable habitats reached 24.014 × 10³ km² for Malus sieversii and 18.990 × 10³ km² for Prunus cerasifera. Future climate projections revealed a consistent and significant contraction trend in suitable habitats for both species, with the magnitude of habitat loss escalating with increasing radiative forcing and longer projection time horizons. Specifically, under the high-emission SSP585 scenario by the 2070s, the suitable habitat area is projected to decline by 7.579 × 10³ km² for Malus sieversii and 9.883 × 10³ km² for Prunus cerasifera relative to the baseline. Our findings delineate climate-vulnerable hotspots of wild fruit forests and provide a robust spatial scientific basis for prioritizing in situ conservation, targeted habitat restoration, and anthropogenic disturbance regulation to support the long-term persistence of these irreplaceable wild fruit germplasm resources under accelerating global climate change. Full article

Although soil nematodes are central to belowground energy flow, how vegetation and soil aggregate characteristics interactively regulate the nematode community structure and energy dynamics remains poorly understood. We investigated 80 soil samples from five vegetation types—Prunus armeniaca L. (AV), Pinus tabuliformis Carrière (PT), Caragana korshinskii (CK), Medicago sativa L. (MS), and native grass Stipa bungeana (SB)—and four aggregate sizes (LMA > 2 mm, MMA 0.25–2 mm, SMA 0.053–0.25 mm, and MA < 0.053 mm) on the Loess Plateau. Vegetation types showed clear functional differentiation, in which AV dominated bacterivore diversity and energy flux in LMA, CK enhanced fungivore and herbivore energy flow, SB supported omnivore–carnivore energy flux, and PT exhibited suppressed communities. Fauna analysis of the EI (enrichment index)–SI (structural index) plot revealed aggregate-dependent food web structuring, where all vegetation types clustered in quadrant C (structured, low enrichment) in small aggregates, while PT and MS shifted to quadrant D (structured, enriched) in larger aggregates. SEM showed that energy flux and energy uniformity are driven by nematode abundance (p < 0.01) and diversity (p < 0.01), respectively, with soil aggregates promoting uniformity (p < 0.05) but suppressing total flux (p < 0.05), thus revealing a trade-off between energy throughput and distribution equity. CK maximizes total energy flux, while AV maintains high energy uniformity; as such, they could be keystone restoration species in the study area. This study provides mechanistic insights into soil food web energetics and offers an empirical foundation for optimizing vegetation restoration strategies on the Loess Plateau. Full article

Global biodiversity is declining at an alarming rate; however, evidence suggests that this decline occurs far more slowly on Indigenous-owned land. This can be attributed to cultural worldviews in which protecting nature and living in harmony with the environment are fundamental principles, an ethos central to African societies and many other Indigenous communities worldwide. This study examines the role of Vhavenda traditional belief systems, Indigenous knowledge, and cultural practices in the management and conservation of natural resources and the environment. In contemporary Limpopo Province, the Vhavenda clans of northern South Africa remain among the country’s most traditional communities, continuing rituals and practices that have been transmitted across generations. According to the 2022 national census, the area inhabited by the Vhavenda tribe, records the country’s highest concentration of centenarians, a demographic pattern which they attribute to the region’s cultural continuity and relative geographical isolation, which have enabled the preservation of its spiritual and ecological heritage. The research employed an insider ethnographic methodology, collecting data through personal interviews and a focus group discussion. Findings reveal that Indigenous beliefs, knowledge systems, and taboos play a substantial role in promoting sustainable land use. They restrict development on ecologically sensitive landscapes and discourage harmful practices, such as deforestation and cultivation along water bodies. These practices are enforced through complex customary laws, often articulated through prohibitive norms (“thou shalt not”), that safeguard plants, animals, water sources, and other natural resources. The study further illustrates that these prohibitions reflect a nuanced understanding of the biophysical environment, with the most sensitive and vulnerable ecosystems and ecologically important species, including keystone, foundation, and indicator species, receiving protection. Overall, the research shows the importance of recognising, protecting, and integrating Indigenous cultural systems as a critical component of effective biodiversity conservation. Full article

Baihua Reservoir, a typical large waterbody in the karst region of southwestern China and an essential drinking water source, is characterized by a high carbonate buffering capacity that profoundly shapes the structure and function of its phytoplankton community. This study systematically elucidates the multi-dimensional driving mechanisms underlying seasonal phytoplankton community assembly in karst reservoirs by integrating multiple analytical models—including the Neutral Community Model, β-diversity decomposition, co-occurrence network analysis, XGBoost-SHAP machine learning, and Partial Least Squares Path Modeling—based on monthly sampling at five sites from 2020 to 2024. The results revealed that: (1) Stochastic processes dominated community assembly across all four seasons, while deterministic processes played a crucial role in local species turnover. (2) The co-occurrence network structure showed significant seasonal dynamics, with the composition of keystone species adaptively shifting in response to changing environmental conditions. (3) The key environmental factors influencing the phytoplankton community exhibited clear seasonal patterns, primarily pH, NH₃-N, and COD_Mn in spring; water temperature, COD_Mn, and NH₃-N in summer; TN, TP, and pH in autumn; and pH, water temperature, and DO in winter. To support the sustainable management of karst reservoirs, we propose seasonally differentiated strategies derived from our phytoplankton community analysis: target COD_Mn reduction in spring and summer, focus on TN and TP load control in autumn, prioritize water column stability in winter, and maintain hydrological connectivity and pH monitoring year-round. This approach enhances phytoplankton community stability, safeguards drinking water safety, and provides a targeted management model for similar reservoir ecosystems globally. Full article

Permafrost regions serve as sensitive indicators of global warming due to their ecological sensitivity and role as climate archives. To study how soil microbial communities in seasonal permafrost respond to freeze–thaw alternations, we analyzed composition and diversity during freezing, freeze–thaw, and thawing stages, identifying key taxa and environmental drivers. Our results identified 11 known fungal phyla and 13 dominant genera in permafrost regions. Most dominant fungi showed stable abundance during soil warming. However, the genera Inocybe and Sebacina were significantly suppressed when transitioning from frozen to freeze–thaw conditions. Fungal species diversity gradually increased with rising temperature and freeze–thaw frequency, with thawed soil showing higher richness and evenness. Frozen, freeze–thaw, and thawed soil were respectively associated with 90.48%, 71.43%, and 66.67% of node species. Adjacent stages shared 57.14% of coexisting species. Keystone node species declined progressively from frozen to thawed stages, indicating substantial yet continuous community reorganization. Furthermore, total carbon, organic carbon, available nitrogen, and phospholipid fatty acids peaked in freeze–thaw alternating soil. Active fungal biomass and species richness were most strongly correlated with soil carbon, temperature, and moisture. Overall, the influence of nutrients on soil fungi was limited across different freeze–thaw stages, while temperature emerged as the primary driver reshaping fungal community structure during freeze–thaw dynamics. Full article

Periodontitis is a dysbiosis-driven inflammatory disease in which a pathogenic subgingival biofilm disrupts the host–microbe equilibrium and promotes progressive loss of tooth-supporting tissues. While periodontal destruction has traditionally been explained mainly through the host immune response, increasing experimental and clinical evidence suggests that epithelial–mesenchymal transition (EMT)-like changes in the gingival epithelium may contribute to barrier failure and tissue remodeling during disease progression. EMT is characterized by reduced epithelial adhesion and polarity, alongside a shift toward a mesenchymal-like phenotype with enhanced motility and impaired epithelial barrier function. This narrative review focuses on how periodontal pathogens, particularly red complex organisms and keystone species, may trigger gingival EMT through virulence factors such as gingipains, fimbriae, lipopolysaccharide, and outer membrane vesicles. These microbial signals can hijack host pathways including TGF-β/Smad, Wnt/β-catenin, and Notch to drive EMT-associated transcriptional changes and downstream functional consequences. Collectively, pathogen-induced gingival EMT may facilitate deeper microbial invasion, perpetuate chronic inflammation, impair wound healing, and contribute to fibrotic remodeling, ultimately linking microbial dysbiosis to connective tissue destruction. Understanding these mechanisms may support the development of EMT-related biomarkers and targeted interventions aimed at preserving epithelial barrier stability in periodontitis. Full article

The eastern honeybee (Apis cerana) is a keystone pollinator for native ecosystems and agricultural crops in China. However, its distribution faces significant uncertainty due to accelerating climate change. To quantify these risks and inform management strategies, we employed an ensemble species distribution model (Biomod2) integrating ten algorithms to project the suitable habitat of the eastern honeybee under current and future (2060s and 2100s) climate scenarios (SSP126, SSP245, and SSP585). The ensemble model achieved an excellent predictive performance (AUC > 0.9, TSS > 0.8). The current suitable habitat spans approximately 1.47 million km², primarily south of the Yangtze River. Biomod2 simulation indicates that the precipitation of the wettest month and mean diurnal temperature range are the dominant environmental stressors influencing the shift in the spatial distributions of the eastern honeybee. Comparisons between current and future climate scenarios reveal a distinct trend of spatial range contraction in southern China and a northwestward shift of the habitat centroid. The most severe impact is projected under the SSP585 scenario, with a potential net habitat loss of 42.25% by 2100. We propose a dynamic conservation strategy that prioritizes the protection of southern climate refugia while managing habitat connectivity to facilitate the species’ migration, thereby safeguarding agricultural resilience. Full article

Porphyromonas gingivalis is a keystone pathogen in periodontitis, known for its ability to invade gingival epithelial cells and persist intracellularly. Conventional antimicrobials are often ineffective against intracellular pathogens, and natural products remain poorly explored in this context. Here, we investigated the antimicrobial effects of Boswellia serrata extract and its bioactive compounds on the dynamics of P. gingivalis infection in human gingival epithelial cells. During early times of infection, B. serrata extracts stimulated phagocytosis and increased bacterial internalization, suggesting modulation of epithelial uptake mechanisms. At later times of infection, B. serrata increased production of reactive oxygen species (ROS) in host cells and markedly reduced intracellular bacterial load. The antimicrobial effect was abolished by the ROS scavenger N-acetylcysteine, confirming a role for oxidative mechanisms in the clearance of P. gingivalis. Similar results were obtained with 3-O-acetyl-11-keto-β-boswellic acid (AKBA), one of the major boswellic acid derivatives found in B. serrata extract. These findings reveal a dual role of B. serrata compounds in response to P. gingivalis infection, in which B. serrata initially facilitates bacterial entry and subsequently promotes ROS-dependent intracellula These findings provide new mechanistic insights into the regulation of host–pathogen interactions by the natural products found in B. serrata. Our results support the therapeutic potential of B. serrata-derived compounds for managing periodontal infections. Full article

Mediterranean agroforestry systems (AFSs), typified by the Iberian Dehesas and Portuguese Montados, are multifunctional landscapes where Quercus species act as ecological keystones sustaining biodiversity, soil fertility, and rural livelihoods. These systems are increasingly affected by complex oak decline syndromes driven by drought, soil degradation, and climate-induced pathogen outbreaks. Conventional chemical controls are often ineffective and environmentally detrimental, underscoring the need for ecologically sound management alternatives. This review synthesizes recent advances in the application of microbial biological control agents (MBCAs) to manage diseases in Mediterranean Quercus species, including Q. ilex, Q. suber, Q. faginea, and Q. pyrenaica. We conducted a structured literature review using predefined keyword searches in Web of Science and Scopus, followed by the screening of records to identify 22 relevant peer-reviewed studies on microbial disease control in Mediterranean Quercus species. We identified 20 peer-reviewed studies that reported that MBCAs—primarily from Bacillus, Serratia, Streptomyces, Trichoderma, Simplicillium and Alternaria—exert biocontrol effects through antibiosis, mycoparasitism, competition for ecological niches, and the induction of host defense responses. Although most experiments were conducted in vitro, some demonstrated significant disease suppression in seedlings infected by Phytophthora cinnamomi, Diplodia corticola, and Biscogniauxia mediterranea. Future research should integrate field-based validation and microbiome-oriented forest management approaches to enable the operational use of microbial-based disease control strategies in AFS landscapes. Full article

Afforestation enhances soil carbon storage through plant and microbial necromass accumulation, yet the roles of carbohydrate-active enzymes (CAZymes) and the microorganisms that encode them (biomass-decomposers) during plantation development remain poorly understood. Here, we integrated shotgun metagenomics with network analysis to decipher the successional dynamics of CAZyme-encoding genes, biomass-decomposers, and their functional linkages across a chronosequence of plantation development in northeastern China. Plantation development increased the abundance of CAZymes involved in lignin, chitin, and glucan degradation. Network analysis of biomass-decomposers revealed that the dominant function of key module M1 gradually shifted from peptidoglycan to lignin degradation through network reorganization during development. Across all developmental stages, the key modules whose dominant functions were peptidoglycan and hemicellulose degradation consistently harbored keystone species. In the overlap-network, these two functions served as dominant functions in more than one key module, confirming their essential role in maintaining fundamental community functions. Stochastic processes predominantly governed the assembly of biomass-decomposers, with increasing influence during development (R² > 0.6). Variation in both biomass-degrading CAZymes and decomposers showed the strongest association with soil organic carbon, with CAZymes further structured by pH and nitrate nitrogen, whereas biomass-decomposers responded to moisture and total nitrogen. Overall, these findings provide new insights into belowground C cycling during plantation development, potentially guiding improved ecosystem management practices for forest restoration. Full article

Nature-based Solutions (NbS) are essential for peri-urban resilience; however, a critical research gap exists regarding the lack of species-specific eco-physiological validation for interventions within complex biocultural systems. This study addresses this gap by assessing the vulnerability of Quararibea funebris, a shade-tolerant tree and biocultural keystone for the tejate economy in Oaxaca, Mexico, currently caught in an anthropogenic ecological trap. A mixed-methods approach was employed, integrating a geospatial analysis of land-use change (1992–2021), microclimatic monitoring, and ethnographic assessment of gendered management. Results reveal the loss of 1552 ha of forest buffer, which has degraded the thermal niche below the species optimum. Urban specimens are subjected to a Daily Light Integral exceeding 38 mol m⁻² d⁻¹, triggering biometric stunting and oxidative stress. Furthermore, given that seed recalcitrance limits ex situ conservation, the species’ persistence relies strictly on a domestic monopoly of irrigation managed by women, who effectively subsidize the environmental deficit. The study concludes that the current backyard conservation model has hit its ecological ceiling; sustainability requires a transition toward landscape-scale NbS—specifically biocultural corridors governed by local female knowledge—to restore the multi-strata canopy required to regulate the species’ eco-physiological limits. Full article

Picea schrenkiana is a keystone species in Central Asian ecosystems currently threatened by climate-driven disease outbreaks. Here, we investigated the causal agent of needle blight and characterized the associated microbial dynamics. By integrating tissue isolation, Koch’s postulates, and high-throughput amplicon sequencing across a disease severity level, we confirmed Lirula macrospora as the etiological agent. Community analysis revealed that disease severity is the primary driver of succession, with alpha diversity peaks at the moderate infection stage. Notably, the abundance of Lirula surged from 2.56% in healthy needles to 65.10% in severe cases, displacing the core endophyte Phaeococcomyces, while potentially beneficial bacteria like Sphingomonas showed only transient enrichment. Furthermore, cross-kingdom co-occurrence network analysis revealed marked topological restructuring whereby the system reached a complex ecological “tipping point” during moderate stage before undergoing significant simplification. As the disease progressed, L. macrospora shifted from a peripheral node to a central hub, effectively dismantling the native microbial network. We conclude that L. macrospora infection triggers a cascading collapse of the needle microbiome, driving a phase shift from a healthy homeostasis to a pathogen-dominated state. These findings elucidate the critical mechanisms of pathogen-microbiome interactions and provide a theoretical basis for the ecological management of P. schrenkiana forests. Full article