Search Results (3,112)

Myrmecochory is a form of seed dispersal mediated by ants. Although this mechanism of dispersal has received less research attention than other dispersal processes, the wide distribution and high biomass of ants mean that it can strongly influence plant dispersal patterns. In particular, the underlying mechanisms and key agents of myrmecochory remain poorly understood in the context of anthropogenic perturbations; furthermore, such research is especially scarce in East Asia. This review aims to elucidate the ecological mechanisms underlying myrmecochory, to explore how this interaction may be affected by urbanization and climate change, and to determine its potential ecological role in disturbed ecosystems. We first review past research on the three major hypotheses proposed for the emergence of ant-mediated seed dispersal—directed dispersal, distance dispersal, and predator avoidance. We then compile taxonomic information on myrmecochorous plants and ants from global databases and regional literature, expanding the checklist of Korean myrmecochorous plants to 130 species and reclassifying them as endangered, rare, or endemic. Our synthesis suggests that invasive ants could threaten myrmecochory by displacing native myrmecochorous ants, increasing seed predation, and facilitating the dispersal of invasive plants. Moreover, the urban heat island effect and habitat fragmentation could disturb the dispersal, germination, and growth of myrmecochorous plants, threats that may be further intensified by climate-driven phenological mismatches. Consequently, in temperate East Asian countries experiencing anthropogenically generated environmental changes, myrmecochory emerges as a pivotal ecological process that underscores ecosystem vulnerability and resilience. Ultimately, incorporating these plant–ant interactions into biodiversity monitoring is essential for predicting ecosystem shifts and designing robust, proactive conservation strategies in changing environments. Full article

Trillium camschatcense, a plant renowned for its ecological and medicinal value, is predominantly found in the temperate forests of East Asia. However, its habitat is increasingly threatened from climate change, habitat fragmentation, and intensified human activities. In this study, the Maxent (Maximum Entropy) model was used to assess the current ecological suitability of T. camschatcense based on historical climate data (1970–2000), and further simulate its potential distribution shifts under multiple future climate change scenarios to predict long-term habitat variation trends across northeast China.All modeling and spatial mapping analyses were performed using MaxEnt and ArcGIS 10.8.1 software. Drawing upon 93 known distribution points and 26 pertinent environmental variables covering climate, soil, and elevation, we built species distribution models for both present and future periods to pinpoint the crucial environmental factors influencing its distribution. Our findings revealed that elevation, soil nitrogen content, seasonal temperatures, annual precipitation, mean temperature during the coldest quarter, and mean diurnal temperature range were the primary factors influencing the distribution of T. camschatcense. Notably, highly suitable habitats were predominantly concentrated in Baishan City and the southwestern region of Yanbian Korean Autonomous Prefecture in Jilin Province. This insight offers valuable scientific guidance for the conservation planning, sustainable utilization, and potential introduction and cultivation of T. camschatcense. Furthermore, targeted conservation strategies can help identify climate refugia and protect climatically stable habitats for the long-term persistence and resilience of the species under continuous global warming. Full article

Desiccation, ionizing radiation, ultraviolet exposure, and oxidative stress impose severe physicochemical stress that threatens the integrity of both DNA and RNA. Water loss promotes molecular crowding, protein and membrane destabilization, and the accumulation of reactive oxygen species (ROS), while rehydration can intensify oxidative injury and expose lesions accumulated during metabolic suppression. As a result, stress-tolerant metazoans must do more than survive water loss: they must also protect, monitor, and restore nucleic-acid integrity. Here, we review how tardigrades, bdelloid rotifers, Artemia, nematodes, and selected insect species preserve genomic and transcriptomic integrity under extreme dehydration, oxidative stress, and radiation-related insults. We compare conserved defence systems, including antioxidant enzymes, trehalose, LEA proteins, heat shock proteins, and core DNA repair pathways. These pathways include base excision repair, nucleotide excision repair, homologous recombination, and non-homologous end joining. We then examine how these conserved mechanisms contrast with lineage-specific innovations, such as the tardigrade proteins Dsup, TDR1, and TRID1, as well as the unusual genome plasticity of bdelloid rotifers. We argue that stress biology of these organisms is best understood through a framework that distinguishes damage prevention during drying from repair and recovery during rehydration. In this framework, extremotolerant metazoans provide biologically informative models for understanding oxidative nucleic-acid damage, redox defence and the molecular logic underlying radioprotection and dry-state preservation. Full article

The frequency and intensity of heatwaves are increasing annually worldwide due to climate change. Combined with the urban heat island effect, elevated heat stress episodes threaten the survival and performance of urban trees, in turn reducing their ecosystem benefits. For this reason, the foliar heat tolerance of 35 Malus genotypes (two species, 32 cultivars, one variety, one hybrid) was evaluated under controlled laboratory assays. Heat injury to foliar tissue was quantified using chlorophyll fluorescence (Fv/Fm) to assess photosystem II (PSII) damage and an electrolyte leakage index (ELI) to evaluate cellular membrane integrity. A preliminary dose–response experiment using six genotypes exposed to a temperature gradient (40–50 °C) was conducted to establish thermal response curves and derive LT₅₀ values (temperature at 50% decline in Fv/Fm). These analyses confirmed substantial genotypic variation in thermal tolerance and identified 45 °C as an optimal discriminatory temperature for large-scale screening. This temperature was subsequently applied to assess heat injury across all 35 genotypes. Measurements were conducted in May (spring foliage) and August (summer foliage) to evaluate ontogenetic influences. In some instances, only one genotype was available for experimental purposes. Consequently, conclusions regarding genotypic differences in heat tolerance are based on replicated datasets, whereas genotypes represented by single-tree sampling are presented for descriptive purposes only. Heat stress significantly affected Fv/Fm and ELI, with strong genotype and seasonal effects recorded. In most genotypes, foliar damage was greater in spring than in summer. Good correlations between Fv/Fm and ELI confirmed their value as complementary physiological measures of heat tolerance in plants. Of the 35 genotypes evaluated, Malus sargentii, M. ‘Prairifire’, M. baccata ‘Jackii’, M. ‘Royal Fountain Huber’ and M. Donald Wyman were the most heat tolerant. The substantial variation in foliar heat tolerance detected across the 35 genotypes tested demonstrates potential for selecting Malus genotypes with superior foliar heat tolerance and highlights opportunities for identifying heat resilient candidates among other under-utilized urban tree taxa. Full article

Climate-driven changes in oceanographic conditions are increasingly affecting the distribution of marine species, particularly vulnerable elasmobranchs. The undulate ray, Raja undulata, is a Near Threatened batoid species distributed throughout the northeastern Atlantic Ocean and parts of the Mediterranean Sea, yet its potential response to future climate change remains poorly understood. This study assessed current and future habitat suitability using species distribution modelling approaches and CMIP6 climate projections under the SSP245 scenario. Species occurrence records were compiled from biodiversity databases and published sources, and environmental predictors were selected following multicollinearity screening. Among twelve evaluated modelling algorithms, MaxEnt showed the highest predictive performance (AUC = 0.99; TSS = 0.95) and was selected for subsequent analyses. Current habitat suitability was concentrated along the Iberian Peninsula, the Bay of Biscay, the English Channel, and parts of the western Mediterranean Sea. Future projections indicated substantial habitat contraction, with habitat loss (57.3%) greatly exceeding habitat gain (2.2%), resulting in a southward redistribution of suitable habitats. Minimum phytoplankton concentration, sea surface temperature, and silicate concentration were identified as the most influential environmental predictors. Areas predicted to remain suitable under both current and future conditions may represent important climate refugia for the species. Overall, the results indicate that R. undulata is highly vulnerable to future environmental change and highlight the need to incorporate climate-driven habitat shifts into conservation planning, fisheries management, and long-term monitoring strategies. Full article

Strawberries, as an important economic crop, are widely planted worldwide. Fusarium oxysporum, belonging to FOSC (Fusarium oxysporum species complex), is widely present in plants. Among them, Fusarium oxysporum f. sp. fragariae (Fof) is one of the most important pathogens on strawberry and has pathogenic specificity toward strawberry hosts. In recent years, diseases caused by Fof have seriously threatened the strawberry industry. Secreted in Xylem (SIX) genes play important and different roles in F. oxysporum. In this study, we knocked out SIX9 in Fof to analyze its functions. The mycelial growth rate of ΔFofSIX9 was significantly lower than that of the wild type, but the difference in spore production was not significant. The pathogenicity of ΔFofSIX9 toward four different representative strawberry varieties was significantly reduced, manifested by the decrease in the severity of plant wilt, root rot, and crown rot. In addition, compared to the wild type, the activities of superoxide dismutase (SOD) and catalase (CAT) in ΔFofSIX9-infected plants were significantly increased, while the content of malondialdehyde (MDA), hydrogen peroxide (H₂O₂), and superoxide anion (O₂⁻) were significantly decreased. So ∆FofSIX9 could reduce the pathogenicity of the wild type by affecting the host plant’s defense response against infection of Fof. Full article

Septic shock is a life-threatening manifestation of sepsis characterized by dysregulated immune responses, excessive inflammation, oxidative stress, and progressive multi-organ dysfunction. Despite advances in antimicrobial therapy and supportive care, mortality remains high, highlighting the need for therapeutic strategies that target immune dysregulation in addition to infection control. The review evaluates the potential of hollow nanoparticles as immunomodulatory therapies for septic shock, focusing on lipid-based, polymeric, protein-based, biomimetic, inorganic, carbon-based, and hybrid nanoparticle platforms. Current evidence suggests that these systems can modulate key pathological processes through reactive oxygen and nitrogen species (RONS) scavenging, regulation of inflammatory signaling, macrophage modulation, neutralization of bacterial toxins and antigens, and, in some cases, direct antimicrobial activity. Among the available platforms, lipid-based and biomimetic nanoparticles appear to possess the greatest translational potential owing to their favorable immunomodulatory properties and improved biocompatibility. Nonetheless, several challenges continue to limit clinical translation, including nanoparticle-associated systemic and organ toxicity, unintended immunogenicity, limited long-term safety data, and the lack of standardized comparative studies across nanoparticle classes. Despite these limitations, the progression of VBI-S, a phospholipid nanoparticle formulation, to Phase III clinical evaluation highlights the growing clinical feasibility of such nanoparticle-based approaches for septic shock. Future research should focus on optimizing nanoparticle design, improving safety profiles, and establishing standardized preclinical and clinical evaluation frameworks. Collectively, the available evidence suggests that hollow nanoparticles represent a promising antibiotic-independent strategy for restoring immune homeostasis and improving outcomes in septic shock. Full article

Heat stress severely impairs immune function and threatens dairy cow health and productivity. Although heat stress suppresses bovine neutrophil (PMN) phagocytosis, its effects governing PMN survival remain unclear. L-arginine (L-Arg) exerts immunomodulatory and cytoprotective effects, yet its role in repairing heat-damaged PMN has not been defined. In this study, an in vitro heat stress model (42 °C for 2.5 h) was established. Heat stress significantly reduced cell viability, induced abnormal nuclear morphology, and triggered apoptotic signaling, accompanied by severe oxidative stress (elevated reactive oxygen species (ROS)/Malondialdehyde (MDA), decreased SOD/glutathione peroxidase (GSH-Px)). The ROS scavenger N-Acetylcysteine (NAC) mitigated both oxidative stress and apoptosis, confirming oxidative stress as a core mediator of PMN apoptosis induced by heat stress. Pretreatment with 4 mmol/L L-Arg significantly alleviated heat-induced oxidative damage and apoptosis. Mechanistically, in bovine PMN, we first demonstrated that heat stress blocks nuclear factor erythroid 2-related factor 2 (NFE2L2) nuclear translocation; inhibition of NFE2L2 (ML385) abolished L-Arg’s protection, verifying the NFE2L2-dependent ROS scavenging pathway. In conclusion, this study reveals that heat stress induces bovine PMN oxidative injury and apoptosis by suppressing NFE2L2-mediated ROS scavenging, and L-Arg restores PMN viability and immune resilience by reactivating the NFE2L2 antioxidant pathway. These findings provide a targeted L-Arg supplement strategy to improve PMN survival and disease resistance in heat-stressed dairy cows. Full article

Cadmium (Cd) pollution adversely affects crop productivity and grain quality. Durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.), a widely consumed cereal crop, can accumulate substantial levels of Cd in edible tissues, threatening human health. Therefore, advances in understanding Cd toxicity in plants and the molecular mechanisms underlying Cd accumulation and detoxification are needed to develop resistant cultivars and ensure safe food production. Although Cd homeostasis has been previously studied in bread wheat, its accumulation varies among species and cultivars owing to differences in their physiological and genetic makeup. However, the molecular mechanisms underlying Cd homeostasis in durum wheat have not been comprehensively reviewed. Here, we synthesize current knowledge on the molecular basis of Cd uptake, transport, and detoxification in durum wheat. Specialized transporter families, including MRPs/ABCCs, HMAs, and members of the YSL, ZIFL, and IREG families, play critical roles in mediating Cd compartmentalization and limiting its cytosolic toxicity. Genes such as HMT1, TdHMA3-B1a, and members of the NAS gene family significantly reduced Cd accumulation in grains. Future studies should focus on the integration of physiological, molecular genetics, and multi-omics approaches to uncover the regulatory networks controlling Cd homeostasis in durum wheat. Full article

Introduction: As apex and mesopredators, elasmobranchs help maintain marine ecosystem balance by shaping food-web structure and habitat connectivity, yet more than one-third of species are threatened with extinction. Identifying where and when they aggregate within atoll systems is therefore a prerequisite for spatially explicit conservation planning. Lhaviyani Atoll, in the central Maldives, lies within a recognised Indian Ocean elasmobranch hotspot and hosts two Important Shark and Ray Areas (ISRAs), yet fine-scale information on aggregation sites, habitat partitioning and seasonal use remains limited. Objective: To map persistent activity hotspots, characterise habitat partitioning between sharks and batoids, quantify seasonal and inter-annual dynamics, and provide an ecological basis for habitat-focused conservation in Lhaviyani Atoll. Methodology: Using a seven-year (2017–2024) opportunistic dive-log dataset of 12,732 SCUBA surveys and 142,994 elasmobranch records across 94 dive sites, spatial kernel-density estimation was applied separately to sharks and batoids to identify activity hotspots and visualise spatial overlap. Habitat associations were examined across substrate types and reef geomorphic zones. Seasonal and inter-annual dynamics in relative abundance and diversity (Shannon, Pielou’s evenness) were quantified across monsoon phases and the 2017–2024 period. Results: Twenty-eight species (14 sharks, 14 batoids) were recorded, including 23 listed as threatened on the IUCN Red List (4 Critically Endangered, 12 Endangered, 7 Vulnerable). Four persistent activity hotspots were identified along the northern atoll rim, two overlapping with the Fushifaru Kandu and Kuredhu–Huravalhi–Komandoo ISRAs. Sharks were concentrated along more complex exposed and semi-sheltered slopes and high-flow channels, with significantly higher occurrence on reef and sheltered reef slopes and lower occurrence on rubble and sand substrates; batoids were distributed broadly within lagoonal habitats with no strong substrate or geomorphic preferences. Relative abundance and diversity peaked during the late southwest monsoon (August–September) and declined into the northeast monsoon (December–March); after 2021, diversity and evenness increased while overall abundance declined. Conclusions: Persistent hotspots, contrasting habitat use by sharks and batoids, and consistent monsoonal seasonality support the ecological relevance of existing ISRAs in Lhaviyani Atoll, while providing finer-scale information on habitat partitioning and additional priority areas for threatened elasmobranchs, including four Critically Endangered species. Full article

The aims of this study were to determine the geographical range and habitats of the Verbascum species in the Arabian Peninsula and to assess their conservation status at national, regional, and global levels by using the International Union for Conservation of Nature (IUCN) Red List categories and criteria. Verbascum is represented by 16 species with four varieties in the area of the study, and most of these species are endemic to Saudi Arabia, Yemen, Oman, and the United Arab Emirates (UAE). This study is based on an ecogeographic survey, which was conducted using herbaria collections, literature sources, and fieldwork. The findings showed that the genus is distributed in three main regions in the Arabian Peninsula, which include northern Saudi Arabia, the Asir and Yemen highlands, and the Hajar mountains in Oman and the UAE. In addition, most species of Verbascum in the region are at high risk of extinction. Nine taxa are threatened, four of which are assessed as Critically Endangered, four as Endangered, and one as Vulnerable. Furthermore, four species are assessed as Near Threatened, while another five species are assessed as of Least Concern. Threats to the Verbascum species in the region are overgrazing, suburban and agricultural expansion, climate change, invasive species, recreational activities, tourism, war, and civil unrest, leading to human intrusion and disturbances. Some important strategies for conserving and managing Verbascum species on the Arabian Peninsula are recommended here. Full article

Plant-parasitic nematodes, particularly the root-knot nematode Meloidogyne incognita, severely threaten agricultural production in tropical and subtropical regions. Although nematode-trapping fungi have been considered environmentally friendly alternatives to chemical nematicides, their field performance often remains inconsistent due to limited ecological adaptation. This study combined a field survey of crop-associated nematode communities with laboratory and greenhouse evaluation of selected nematode-trapping fungal isolates under subtropical conditions. Field surveys across multiple crops identified M. incognita as the dominant plant-parasitic nematode species. Five fungal isolates with different trapping mechanisms were compared for growth under contrasting nutrient conditions and nematode-trapping efficiency. Among them, Drechslerella brochopaga (NTF2), which forms constricting rings, showed superior growth stability under nutrient-limited conditions and the highest nematode mortality in vitro. In greenhouse experiments, NTF2 reduced root gall formation in two of three independent trials, indicating potential but variable suppression of M. incognita on pumpkin. These findings highlight the importance of ecological adaptation and trapping strategy in determining the effectiveness of nematode-trapping fungi for sustainable nematode management. Full article

Introduction: Mediterranean coastal wetlands are highly dynamic ecosystems that support diverse fish communities and are often of high conservation value. The Ebro Delta is one of the most important coastal wetlands in the Western Mediterranean, and knowledge of fish assemblages is essential for its effective conservation and management. Environmental DNA (eDNA) metabarcoding provides a non-invasive approach that can potentially complement conventional surveys for fish biodiversity monitoring. Objective: This study aimed to evaluate the potential of eDNA metabarcoding as a complementary tool to conventional fyke net surveys for fish biodiversity monitoring in the Mediterranean coastal wetlands. Methodology: In 2022, fish assemblages were surveyed across 12 areas of the Ebro Delta using eDNA metabarcoding (12S MiFish) and conventional fyke net sampling. Results were compared with a 22-year historical dataset. Results: A total of 27 fish taxa were detected, 13 of which were exclusive to eDNA, 11 were shared between methods, and three were recorded only by fyke nets. The reliability of eDNA metabarcoding was supported by the detection of endangered species, such as Anguilla anguilla and Apricaphanius iberus; ubiquitous taxa, such as Atherina boyeri and Pomatoschistus microps; and invasive species, such as Gambusia holbrooki and Cyprinus carpio. Detection of invasive species was maximized using eDNA. While eDNA revealed higher species richness than fyke nets, community composition differed significantly between methods, reflecting distinct detection patterns. eDNA preferentially detected non-benthic species, whereas fyke nets were more robust for benthic taxa detection. eDNA recovered most historically recorded species but failed to detect some taxa, such as Misgurnus anguillicaudatus and Sardina pilchardus. Despite richness differences, the two methods provided complementary views of fish assemblages, highlighting method-specific detection limitations and opportunities. Conclusions: eDNA does not fully replace conventional surveys and their combined use improves the detection of threatened and invasive species, better supporting conservation and management. Full article

Introduction: Elasmobranchs play a crucial role in ecosystem regulation, but they are highly vulnerable to rapid environmental changes, particularly those driven by anthropogenic activities. Therefore, elasmobranchs are among the most threatened vertebrate groups worldwide, with overfishing and habitat degradation representing the primary threats to their survival. To address these challenges, in situ and ex situ conservation programs are complementary approaches. Objective: The implementation of assisted reproductive technologies, still poorly developed for elasmobranchs, represents a critical component of these ex situ strategies. Focused on that aspect, the main goal of this work was to get a better understanding of the sperm cells morphologies of different Mediterranean elasmobranch species. Results: The Elasmobranchii spermatozoa possesses a long and he-lical head, an elongated midpiece, and a flagellum supplemented with additional ultrastructural components to its axoneme. The comparative analysis of sperm head morphology revealed substantial interspecific variation among the studied elasmobranchs. Head length was relatively conserved, ranging from 48.5 to 62.0 μm, whereas helical parameters showed much greater variability. S. canicula and M. mobular exhibited the most compact head morphology, characterized by short helical wavelengths, low amplitudes, and the highest numbers of helices. In contrast, the batoids R. rhinobatos, R. radula, and R. clavata displayed broader, more widely spaced helices and fewer turns. Phylogenetic patterns were partially evident, as the closely related rajids shared very similar sperm morphology, while R. rhinobatos showed a comparable batoid morphotype. However, similarities between the distantly related M. mobular and S. canicula, and differences between the scyliorhinids S. canicula and G. melastomus, suggest that ecological and reproductive factors, in addition to phylogeny, have influenced the evolution of sperm head morphology in elasmobranchs. Conclusion: Elasmobranchii species possess big spermatozoa (compared to bony fishes) with an elongated helical head and tail similar to one currently existing (but later diverged) in birds, reptiles, and amphibians, which can be considered an evolutionary ancient. Sperm head morphology varies markedly among elasmobranchs, mainly regarding helical traits rather than head length. While phylogeny explains similarities among rajids, convergent patterns in distantly related species suggest that additional ecological and reproductive factors influence sperm evolution and structural design. Full article

Transitional waters—such as estuaries, lagoons, deltas, and coastal wetlands—are dynamic environments where freshwater and seawater interact, forming highly productive and biologically diverse ecosystems. Shaped by temperature and salinity gradients, tidal influence, sediment transport, and nutrient-rich conditions, these habitats support diverse ecological functions. Their structural complexity—including seagrass beds, salt marshes, mudflats, and mangroves—provides essential habitats for many fish species. These areas are crucial for fish life cycles, serving as nurseries, spawning grounds, feeding zones, and refuges from predators. Many commercially important species depend on them during early life stages before moving offshore, making them vital for both commercial and recreational fisheries. Beyond food provision, they deliver key ecosystem services, including water purification, coastal protection, and carbon storage. Research on the fish community of the Ria Formosa lagoon in Portugal since the 1980s highlights long-term changes in the fish community and the dominant role of habitat structure and temporal dynamics. Subtidal seagrass beds support higher fish abundance and diversity than unvegetated areas, acting as key nursery habitats and provide important fish provisioning services. Seasonal variation is also central, driven by recruitment pulses of marine migrants in late winter–spring. Recent pressures on this system have been driven by human activity and environmental change. Seagrass loss reduces nursery and feeding areas, while pollution degrades water quality. Overfishing (including illegal fishing), recreational activities, and aquaculture expansion add stress. Climate warming and invasive species such as Caulerpa prolifera, further disrupt ecosystem balance and threaten biodiversity. Sustainable management—such as habitat restoration, protected areas, and integrated policies—is essential to preserve the ecological and economic value of this unique lagoon. Ongoing research, monitoring, habitat restoration, and stakeholder engagement remain critical for ensuring resilience. Full article