Evaluation of the combined toxicity of copper and benzo[a]pyrene to phytoplankton in the Jiaozhou Bay based on mesocosm experiment.

Articular cartilage, once damaged by trauma or diseases such as osteoarthritis, has a limited capacity for self-repair due to its avascular nature. Repairing this tissue remains a clinical challenge, further complicated by its high mechanical loading, hierarchical architecture, and specialized ionic environment. Current clinical treatments often yield inferior repair tissue and can cause donor-site morbidity. Cartilage tissue engineering (CTE) seeks to overcome these limitations by generating functional tissue in vitro, typically using growth factors to regulate cell migration, proliferation, chondrogenic differentiation, and extracellular matrix synthesis. However, growth factors are unstable, costly, and may cause side effects. Recently, ionic medicine has emerged as a promising alternative, harnessing the biological activity of mineral ions to modulate cellular processes similar to growth factors. This review summarizes the state of the art in ion-releasing biomaterials for cartilage repair, with particular emphasis on systems delivering silicon, lithium, magnesium, strontium, copper, zinc, cobalt, manganese, molybdenum, cerium, europium, and vanadium. In addition, less commonly studied ions, such as boron, iron, and selenium, that are relevant to cartilage biology but have not yet been systematically incorporated into biomaterials, are reviewed. Subsequently, the effects of these ions are comparatively analyzed and classified as either stimulative or protective. In addition, the synergistic and antagonistic interactions among simultaneously released ions are discussed. Furthermore, ion-releasing biomaterial systems employed in CTE are classified and evaluated. Overall, evidence suggests that ionic medicine holds considerable promise as a valuable alternative to growth factor- and surgery-based approaches for articular cartilage repair.

Enhancing brain health through omega fatty acids: Ahiflower oil and oleic acid as novel plant-based nootropic ingredients targeting the microbiome–Gut–Brain Axis

Proteomic analysis reveals metabolic adaptations of Mucor plumbeus during antagonistic interactions with Pichia jadinii

Antagonistic interactions and their impact on species formation and biodiversity maintenance

Roots are pivotal for plant acclimation to environmental challenges, serving as dynamic interfaces for water and nutrient acquisition, signal integration and stress resilience. In nature and agriculture, plants are rarely exposed to single stresses in isolation; instead, they encounter multifactorial constraints such as drought × salinity, heat × nutrient limitation or sequential flooding and drought. These combinations often produce synergistic, antagonistic or neutral interactions that cannot be inferred from single-stress studies. This review synthesizes methodological advances that enable the study of root responses beyond reductionist paradigms. We first discuss growth and performance assays that quantify root architecture, resource uptake and hydraulic function under combined stresses. We then highlight targeted molecular assays and high-resolution omics technologies that reveal stress-specific biochemical and regulatory signatures. Imaging methodologies, ranging from X-ray tomography and MRI to confocal and synchrotron-based approaches, provide spatiotemporal access to root structural and functional dynamics. Finally, we propose integrative frameworks that merge phenotyping, omics and imaging with computational modelling to disentangle the logic of root acclimation under multifactorial conditions. By bridging methodological layers, this review provides a roadmap for advancing plant stress biology toward predictive and translational frameworks, with direct implications for breeding resilient crops in the context of climate change.

The introduction of invasive alien species is a major threat to freshwater biodiversity, particularly in Mediterranean ecosystems where seasonal droughts increase population density and social stress. This study investigated the effects of the presence and of variables densities of two widespread invasive fish species Gambusia holbrooki (Girard, 1859) and Lepomis gibbosus (Linnaeus, 1758), on the behaviour and physiology of the Iberian endemic Squalius alburnoides (Steindachner, 1866). Under baseline density, exposure to G. holbrooki significantly altered the behaviour of S. alburnoides, leading to increased aggression towards conspecifics, enhanced evasion, and a rise in the number of attacks suffered. These behavioral changes were accompanied by a reduction in forebrain dopamine levels, suggesting that dopaminergic influence stress-related responses. In contrast, interactions with L. gibbosus under the same conditions did not produce significant behavioral or physiological effects, although conspecific aggression showed temporal fluctuations. Under high-density conditions, both invaders intensified antagonistic interactions with S. alburnoides. Significant neurochemical alterations occurred solely in fish exposed to G. holbrooki, which showed elevated 5-HIAA concentrations and increased DOPAC/DA and 5-HIAA/5-HT ratios, indicating activation of serotonergic and dopaminergic pathways. Unexpectedly, plasma cortisol levels in S. alburnoides decreased in the presence of both invader species, suggesting a possible downregulation of the hypothalamic-pituitary-interrenal axis under putative social stress. Overall, our results demonstrate that invasive species differentially modulate behavioral and physiological stress responses in S. alburnoides, with G. holbrooki exerting stronger effects than L. gibbosus, and that higher densities amplify these species-specific interactions.

Evolutionary differentiation of duplicated hoxb5 paralogs orchestrates calcium signaling and contractility.

Integrated transcriptome-metabolome analysis reveals attenuated combined toxicity: antagonistic interactions of three thermal processing contaminants in murine kidney-urine systems.

Microbial homeostasis is maintained by the antagonistic capacity of commensal bacteria against cariogenic pathogens. In the oral cavity, commensal Streptococcus, dominant colonizers of the tooth surface, can produce hydrogen peroxide (H2O2), modulating virulent cross-kingdom biofilm formation. To investigate their ecological role, clinical isolates from dental plaque were compared with reference strains, including Streptococcus oralis ATCC 35037 and S. oralis subsp. tigurinus J22 to determine their H2O2-producing capabilities. The antagonistic potential of S. oralis against Streptococcus mutans and Candida albicans was evaluated using microbial and biochemical assessments. In a saliva-coated hydroxyapatite disc model, S. oralis strains were co-cultured with S. mutans and C. albicans. A high H2O2-producing S. oralis J22 inhibited EPS formation in S. mutans and yeast-to-hypha transition in C. albicans, thereby reducing EPS-mediated bacterial-fungal cell colocalization. Time-lapse confocal imaging revealed that S. oralis J22 dominated the biofilm through H2O2-mediated antagonistic interactions. In contrast, the inhibitory effect of S. oralis strains lacking the spxB gene on cross-kingdom biofilms was significantly reduced. These data provide ecological insights into how physicochemical properties of early colonizing commensals shape the structure and virulence of cross-kingdom oral biofilm through antimicrobial-mediated antagonistic activity.IMPORTANCEThe co-existence of S. mutans and C. albicans accelerates the development of severe early childhood caries, particularly under frequent sucrose exposure. This study demonstrates that early colonizing and antimicrobial-producing oral commensal bacteria can disrupt these pathogenic interactions by modulating their physicochemical associations. These findings highlight the potential of enhancing commensal bacteria as part of novel caries prevention strategies. Further characterization of the functional oral microbiota, especially clinically relevant oral commensals, could advance the development of diagnostic biomarkers and microbiome-targeted therapeutics to prevent painful and costly oral diseases.

Bacteria and the viruses that infect them (known as bacteriophages or phages) are important microbial ecosystem members. Antagonistic interactions between different bacteria or between bacteria and phages can profoundly impact population dynamics. Lytic phages are efficient killers that generally infect strains from a single genus or species. Polyvalent phages that target multiple unrelated hosts have been described, but their ecological significance is largely unknown. Here, we investigated how a polyvalent phage (PSA39) alters bacterial dynamics during co-cultures with susceptible hosts. Pseudomonas aeruginosa and Stenotrophomonas maltophilia are unrelated bacterial species that inhabit the same ecological niches, are often co-members of microbial ecosystems, cause similar infections, share mobile genetic elements, and can engage in complex interactions. In the presence of P. aeruginosa and S. maltophilia, PSA39 significantly reduces the recovery of both bacteria but has a stronger impact on S. maltophilia. P. aeruginosa adapts in the presence of PSA39, but S. maltophilia survival is impaired when the two bacteria are grown together and with phage. Furthermore, propagation in the presence of S. maltophilia cells results in higher viral titers. Both bacterial species evolve mutations in pili genes when exposed to PSA39. We propose that P. aeruginosa, S. maltophilia, and PSA39 can serve as a model system to study how polyvalent phages alter co-existing bacterial populations.IMPORTANCEPhages are the most abundant biological entity on the planet, but polyvalent phages that infect multiple bacterial species are poorly understood. Here, we investigated how the polyvalent phage PSA39 affects two susceptible but unrelated bacterial hosts (Pseudomonas aeruginosa and Stenotrophomonas maltophilia). During co-cultures with S. maltophilia, P. aeruginosa quickly develops resistance to this virus and has an antagonistic effect on its bacterial competitor. We find that both bacterial species evolve mutations in Type IV pili genes to resist PSA39 lysis. Our study provides novel insights into the impact that polyvalent phages can have on susceptible bacteria, such as those from natural environments or from infections.

Tea (Camellia sinensis) is a globally significant economic crop, and its desirable quality and health benefits are largely credited to catechin derivatives. Plant growth-promoting rhizobacteria (PGPR), such as Bacillus velezensis, are well-known for enhancing the environmental fitness and disease resistance of plants. However, the regulation of their impact on tea catechin biosynthesis remains unclear. While previous studies have focused on PGPR-facilitated growth promotion in crops like tomatoes and rice, the physiological mechanisms by which microbes regulate secondary metabolism in tea-especially under co-inoculation conditions-remain largely underexplored. This study examined the effects of B. velezensis SD24, isolated from tea rhizosphere soil, on catechin derivative accumulation of tea leaves by altering gene expression and the rhizosphere microbiome. Strain SD24 exhibited broad-spectrum antimicrobial activity against various pathogens due to behaving antimicrobial gene clusters. Tea plants inoculated with SD24 showed significantly increased levels of catechin derivatives in their leaves. This was likely achieved by upregulation of leucoanthocyanidin reductase and anthocyanidin reductase within the phenylpropanoid pathway. Additionally, chlorophyll content was increased. Transcriptomic analysis revealed a notable enrichment in biosynthesis of secondary natural products among the tea genes activated by SD24 inoculation. Metagenomic analysis further demonstrated that SD24 inoculation led to a restructuring of the tea rhizosphere microbiome. Notably, co-inoculation with Piriformospora indica, a beneficial endophytic fungus, suppressed SD24-induced gene expression and catechin accumulation, underscoring its antagonism toward SD24. These findings suggest that B. velezensis SD24 enhances tea quality, probably by transcriptionally activating the synthesis of catechin derivatives, a process associated with the restructuring of the rhizosphere microbiome.IMPORTANCEThe mechanisms through which plant growth-promoting rhizobacteria (PGPR) influence secondary metabolism in perennial crops remain poorly understood. This study demonstrates that Bacillus velezensis SD24, a tea rhizosphere isolate, significantly enhances the accumulation of health-beneficial catechin derivatives in tea leaves. This quality improvement is associated with transcriptionally upregulating key biosynthetic genes (LAR and ANR) and concurrently restructuring the rhizosphere microbiome. Furthermore, we reveal a critical antagonistic interaction, where the beneficial fungus Piriformospora indica suppresses these SD24-induced effects. Our findings provide crucial insights into how specific PGPR strains may directly enhance tea quality by affecting host plant metabolism and the root microbiome, highlighting the complex and tailored microbial interactions that could be harnessed for sustainable agriculture.

Strain engineering has emerged as a powerful strategy to modulate catalytic activity, yet its general applicability remains uncertain, especially for magnetic catalysts where spin effect also plays a critical role in governing reactivity. Here, we reveal a metal-dependent modulation on adsorbate chemisorption to strain, with magnetic metals exhibiting reduced strain sensitivity compared to non-magnetic metals. Using ammonia synthesis as a model reaction, we attribute this behavior to an antagonistic interaction between strain and spin, wherein spin effect counteracts strain-induced chemisorption modulation and becomes stronger with increasing magnetism, originating from the varying shift of d-band center under the combined effects. Kinetic analysis further confirms that strain engineering markedly modulates the reactivity of weakly magnetic or non-magnetic metals by reshaping traditional scaling relations under strain-free conditions, while offering marginal impact to strongly magnetic metals. Accordingly, we propose a practical strain-based strategy to enhance the activity of representative ammonia synthesis catalysts, including Fe, Co, Ni and Ru. Moreover, the metal-dependent strain effect can be extended to key intermediates in other reactions, indicating a general phenomenon and establishing a conditional principle for applying strain engineering in metal catalysts design.

Microplastics (particles 0.1 μm-5 mm) are an increasing ecological problem in aquatic environments. Effects of microplastics on microalgae and interactions with co-occurring contaminants, such as the herbicide glyphosate, are poorly understood. We examined direct effects of microplastics and interactions with glyphosate using the chlorophyte Chlamydomonas reinhardtii grown in saturating irradiance under nutrient-replete conditions. Cells were exposed to polyethylene beads (45-53 µm diameter) at low (0.1 g L-1) or high (1 g L-1) concentrations, in combination with low (44 µM or equivalent bound to beads) or high (220 µM or equivalent bound to beads) glyphosate for 14 days. We measured growth (chl a fluorescence and cells), photosynthetic quantum yield (Fv/Fm) and cell mortality (SYTOX-Green staining). Glyphosate significantly reduced fluorescence-based growth rates and Fv/Fm and increased cell mortality compared to controls, but growth rates of culture exposed to beads alone were higher than controls, despite having lower Fv/Fm. Complex antagonistic interactions between glyphosate and microplastic treatments were observed; microplastics ameliorated effects of glyphosate on growth rates and cell mortality. Comparisons with previous studies emphasize the importance of plastic polymer, microplastic concentration and experimental preparation. Future work should focus on clear experimental protocols, mixed algal species, and use of aged plastics.

The widespread presence of antibiotics in the environment at sub-inhibitory concentrations imposes a selective pressure that promotes the spread of resistance. In the field, antibiotics interact with diverse physicochemical parameters that can attenuate or intensify their fitness effects. Gene expression is a central plastic trait that governs phenotypes at a higher level of integration and modulates the strength of selection, yet how synergistic or antagonistic fitness effects arise from interactions among transcriptional responses remains poorly understood. Here, we characterized gene-expression interactions underlying fitness-level interactions previously identified between a macrolide, temperature and salinity, and proposed a general methodological framework for assessing the impact of multiple stressors on gene expression. We analyzed the transcriptional response of Escherichia coli to azithromycin (AZI) across two salinity and temperature conditions. De novo and antagonistic interactions were prevalent, with evidence of cross-regulations between salt and AZI. High salinity increased tolerance by two orders of magnitude and, similarly to AZI, induced a downregulation of carbon metabolism. Reduced temperature, which canceled the salinity protective effect, enhanced carbon metabolism and counteracted this shift. Salinity additionally restored stress-response pathways, largely repressed by AZI. Third-order interactions attenuated the contribution of salinity relative to AZI, but the number of affected genes declined exponentially with interaction order, suggesting that higher-order interactions at the gene-expression level should play a minor role in the responses to multiple stressors. By modulating transcriptional responses to AZI, simple environmental parameters could reshape the adaptive landscape of antibiotic resistance, potentially altering the spectrum of resistance mutations likely to spread.

Rare earth elements (REEs) are emerging contaminants with escalating environmental releases. However, REE health risk assessment faces critical challenges due to inconsistent cytotoxicity benchmarks and complex multielement exposures. Here, we developed a comprehensive framework to systematically assess the cytotoxic risks of 16 rare earth ions (REIs). The framework integrates single and binary exposures of 16 REIs across eight human cell lines, machine learning models, and population exposure scenario predictions. The high-throughput screening of single exposure on three end points revealed common disruption of cellular energy metabolism, identifying ATP depletion as a robust benchmark point of departure (BPOD). On the basis of the BPOD, 120 binary combinations of 16 REIs indicated predominantly antagonistic interactions among REEs. The consensus machine learning model trained on the single and binary exposure data sets demonstrated robust predictive performance for mixture cytotoxicity. Application of the model to human exposure scenarios showed high risks for the population in mining areas and negligible risks for the general population. The significant linear correlation of cytotoxic responses between cell lines and human primary hepatocytes confirmed the human health relevance and model reliability. Our study provides a toolkit to establish a standardized, scalable, and integrative risk assessment for REEs and other emerging multielement contaminants.

Long-term exposure to fine particulate matter (PM2.5) is associated with respiratory and cardiovascular diseases. PM2.5 consists of a complex mixture of organic and inorganic species, with toxicity varying based on its chemical composition, sources, and physicochemical properties. This study investigates the oxidative potential (OP), cellular oxidative stress, and inflammatory response induced by five distinct chemical fractions of urban PM2.5: water-soluble total, water-soluble metals, water-soluble non-metal, lipid-soluble, and total PM2.5 extract. We also analyzed the synergistic and antagonistic interactions among these fractions contributing to overall PM2.5 toxicity. Comprehensive chemical characterization and OP analysis of PM2.5 extracts revealed that metals primarily drive dithiothreitol (DTT) consumption, while organics predominantly contribute to hydroxyl radical (∙OH) generation. Notably, high PM2.5 samples exhibited significant antagonistic interactions between water-soluble metals and organic fractions in the generation of ∙OH. The water-soluble total fraction induced the highest levels of TNF-α secretion and upregulated the expression of genes associated with inflammation and oxidative stress, including Cxcl2, Hmox-1, and Cyp1a1, emphasizing its dominant role in PM2.5-induced cytotoxicity. Synergistic upregulation of Hmox-1 expression was observed between water-soluble metals and non-metal fractions, whereas Cxcl2 expression was antagonistically modulated. Conversely, the lipid-soluble fraction exhibited an antagonistic effect on TNF-α secretion and oxidative stress gene expression relative to the water-soluble total fraction. These findings highlight the pivotal role of water-soluble components in PM2.5 toxicity and provide a comprehensive framework for understanding the individual and combined effects of chemical fractions on PM2.5-induced toxicity, which is vital for accurately assessing its impact on human health.

Gut Microbiome and Metabolic Responses of Adult Zebrafish (Danio rerio) to the Co-exposure of Polyethylene Microplastics and Levofloxacin.

Citrus waste has been classified as inefficient for biogas production through biological processes due to the presence of limonene and phenolic compounds formed from its hydrolysis. However, the effects of limonene and phenol on hydrogen (H2) production via dark fermentation remains unclear. To address this gap, batch experiments were conducted to evaluate the synergistic-antagonistic interactions between limonene and phenol during dark fermentation without interference from other compounds. For this reason, glucose (5g/L) was used as the substrate, and granular anaerobic sludge was used as the inoculum. Limonene and phenol were added at known concentrations across six binary proportions (100:0, 80:20, 60:40, 40:60, 20:80, and 0:100), and interactions were assessed using the isobologram method. Results indicated an antagonistic interaction; the 40:60 limonene: phenol ratio yielded the highest H2 production, with a total accumulated volume of 296.6 ± 7.9 mL H2. The primary fermentation metabolites were lactic acid, acetic acid, and propionic acid. It was also observed that the concentrations of both limonene and phenol decreased after fermentation, suggesting their partial degradation by fermentative H2-producing microorganisms. Enterobacteriaceae dominated across all treatment combinations, demonstrating their capacity to produce H2 in the presence of limonene and phenol. These findings demonstrate that H2 production is feasible despite the presence of the inhibitory compounds.

Phages as ecosystem engineers of plant microbiomes.