Search Results (9,086)

Plant defences are assumed to evolve in response to the negative effects of virus infection on plant fitness (virulence), and to drive plant–virus coevolution. However, viruses are not always antagonistic symbionts of plants, and the expression of defence traits is environment-dependent. Thus, understanding plant–virus interactions requires analysing the expression of defence traits in the host’s native habitat. Here we analyse the effect of cucumber mosaic virus (CMV) infection, and the expression of resistance and tolerance in the native habitat of a wild Arabidopsis thaliana population. Plants from ten genotypes from that population, which have been shown to differ in resistance and tolerance to CMV in a greenhouse, were inoculated with an Arabidopsis isolate of CMV and transplanted to their habitat. Resistance was rated based on virus accumulation in leaves, and tolerance was rated based on the effect of infection on plant fecundity relative to virus accumulation. Consistent with the greenhouse assays, virulence depended on the host genotype, and polymorphisms for resistance and tolerance were expressed in the field, supporting the validity of the conclusions from the greenhouse assays. Our results also support theoretical predictions on the relationships between pathogen multiplication and virulence and between resistance and tolerance. Full article

Melanoma is a heterogeneous, complex and aggressive disease that, despite recent advances in molecular-targeted drugs and molecular and genetic analysis, represents approximately 65% of skin cancer deaths, and unfortunately survival dramatically decreases in melanoma stages III/IV. In young people there is an increased incidence of developing melanoma; hence new therapeutic strategies must be urgently investigated. Peptidergic systems play a crucial role in these strategies to fight melanoma. The scope of this review is to show the enormous potential of targeting peptidergic systems alone or in combination therapy with standard therapeutic strategies currently used in clinical practice to treat melanoma. In this sense, key points such as peptidergic systems and anti-melanoma treatments, oncogenic/anti-melanoma peptides, peptide receptors, peptidergic systems, melanoma risk and immune system relationships, clinical relevance, peptidergic systems and delivery strategies in melanoma will be discussed. Peptides exert oncogenic, anti-melanoma and dual oncogenic and anti-melanoma effects in melanoma, showing a high functional complexity in regulating melanoma development. A plethora of anti-melanoma strategies have been developed or repurposed for potential clinical applications, including peptide/peptide receptor antibodies, peptide receptor antagonists or agonists, enzyme inhibitors, CAR-macrophages, microRNAs and vaccines. Strategies for peptide delivery and protection from enzymatic degradation have also been developed. Some of the previous anti-melanoma strategies are based on the expression/overexpression of peptide receptors in melanoma cells which is crucial for diagnosis, melanoma risk and progression and metastasis development and for the application of more specific and safer anti-melanoma strategies. A meticulous and in-depth study of the peptidergic systems may help to understand how peptidergic systems regulate melanoma progression and shed light on possible therapeutic applications that can be applied in clinical practice. This review shows the enormous potential of targeting peptidergic systems alone or in combination therapy with standard therapeutic strategies currently used in clinical practice to treat melanoma. The benefits to be gained from these studies will be enormous because the peptidergic systems are promising antitumor targets in melanoma, based on the numerous anti-melanoma strategies that have been developed until now. Full article

Naturally abundant endophytes colonize plants internally without causing harm to their host plants. Endophytes are likely to occupy the same ecological niches as phytopathogens and thus have a high potential to be effective biological control agents. Their demonstrated ability to suppress more than one plant pathogen suggests that they can offer a viable alternative to chemical fungicides and a strategy for decreasing the inoculum potential of soil-borne pathogens. Some biocontrol endophytes are also known to improve soil health and the overall health of plants. However, the results in greenhouse studies do not always translate to consistent field efficacy. In this study, the efficacy of three endophytic bacterial isolates (PRT (Bacillus subtilis), PSL (Bacillus amyloliquefaciens), and IMC8 (Bacillus thuringiesis) were evaluated against Phytophthora capsici in a field environment and compared with two commercial biological fungicides, Serenade^® (Bayer Crop Science, St Louis MO, USA) and Double Nickel^® (Certis Biologicals, Columbia, MO, USA), and water control. Plants were inoculated with the bacteria strains using seed treatment for early plant colonization before transplanting to a field infested with P. capsici. Treatments with commercial bio-fungicides followed label recommendations. Data on plant growth vigor, disease severity, number of fruits, fruit size, total yield per plant, and percent of diseased fruits displayed significant differences between the bacteria treatments. While PRT was the best treatment for most traits, followed by PSL on pepper, PSL and Double Nickel were the best treatments on tomatoes. IMC8 was best for plant vigor and larger fruit size, but with fewer fruits per plant on both crops. This study suggests bacterial isolates PRT, PSL, and IMC8 can provide additional products for growth promotion and P. capsici disease management in pepper and tomatoes. Full article

Light and drought antagonistically regulate stomatal movement, yet the mechanisms for integrating these conflicting signals remain unclear. In this study, the stomatal aperture and photosynthetic parameters under red light (RL), blue light (BL), and white light in different water regimes were evaluated. Transcriptome analysis was conducted during a 0–6 h period of BL exposure, with or without drought, to explore the molecular mechanisms underlying BL and drought-mediated stomatal movement. Under non-drought conditions, BL significantly enhanced stomatal conductance, transpiration rate, and stomatal aperture. After drought stress, BL-treated seedlings exhibited the greatest reductions in these indicators. Transcriptomic analysis revealed that both BL-responsive genes and drought-responsive genes were significantly enriched in overlapping pathways related to plant hormone signal transduction, and biological processes of water/fluid transport. Among these, the aquaporin gene CsPIP2;3 was identified as a core node in the crosstalk between BL and drought signals, and a potential key regulator of stomatal movement. Tissue-specific expression analysis showed its highest expression in mature leaves; GUS staining further confirmed its expression in guard cells and vascular bundles, while subcellular localization verified the plasma membrane localization of its encoded protein. The transcriptomic data provide novel insights into the mechanisms underlying stomatal movement regulated by BL and drought. Full article

Steroid-sensitive cancers (e.g., breast, ovarian, uterine, and prostate cancers) are difficult to control and frequently metastasize to lymph nodes, bone, or lung. Although endocrine research has greatly advanced our identification of the direct roles of steroid sex hormones such as androgens and estrogens on tumor cells in promoting metastasis or recurrence (e.g., treatment with gonadotropin releasing hormone agonists/antagonists, aromatase inhibitors, and estrogen and androgen receptor antagonists), mechanistic insight regarding indirect effects of steroid hormones, including how the innate immune system responds to cancer and is influenced by steroid hormones, is lacking. Despite technological advances in engineering more robust adaptive immunity to combat tumor growth (e.g., CART or checkpoint inhibitors), there remains a relative lack of investigation into the role of innate immunity as a key defense system. Here we discuss recent studies that highlight the significance of neutrophils and their response to tumorigenic conditions with or without steroid hormones in animal models of cancer. We will describe relationships between steroid hormones and neutrophils, with a specific focus on neutrophil extracellular traps (NETs), and how these interactions modulate tumor growth and invasion. Together, these data indicate that combinatorial regulation of both innate and adaptive immunity in the context of tumorigenesis may improve outcomes in cancer therapies. Full article

Background: Although several studies have compared muscle activity in ‘healthy’ and ‘unhealthy’ shoulders, studying ‘healthy’ shoulders alone could improve the understanding of shoulder biomechanics. Objective: This study aims to describe the electromyographic activity of several shoulder muscles during a full range of free active flexion, as well as during abduction and scaption movements, and to compare gender differences in subjects with no history of shoulder pain or pathology. Methods: A cross-sectional descriptive study was conducted with 34 subjects aged between 18 and 60 years of both genders. The activity of the anterior, middle, and posterior deltoid, serratus anterior, infraspinatus, latissimus dorsi, and teres major muscles was measured using surface electromyography. Root Mean Square (RMS) values were calculated as a percentage of Maximal Voluntary Isometric Contraction (MVIC). Results: Regardless of whether they are considered agonists or antagonists, these muscles were active, with no statistically significant differences (Mann–Whitney U test), during both the lifting and lowering phases of the studied movements. Statistically significant differences between movements were observed only in the deltoid (Kruskal–Wallis H test, p < 0.004), which was more active during abduction. Women showed statistically significant muscle activity increase compared with men in some movements, except in the infraspinatus muscle—for example, in the three parts of the deltoid during the lifting phase of scaption (ANCOVA, p = 0.002–0.024). Conclusions: In this sample, the shoulder muscles studied showed comparable activity, acting as agonists or antagonists during shoulder elevation. These findings are exploratory and may help inform future studies on muscle activation in healthy shoulders during more varied functional tasks. Full article

Nitrogen and sulphur are among the most important plant nutrients (along with C, H, and O) and the main elements comprising the organic substance of plants. In this study, it is assumed that light soils (Cambisols) do not naturally meet the nitrogen and sulphur needs of spring wheat and, consequently, impact the phosphorus and silicon content in the plant biomass. Therefore, to determine the effect of N and S on the content and uptake of these elements at specific growth stages (BBCH 30–31: in leaves, BBCH 55–59: in whole plants, BBCH 89–90: in grain and straw), a three-year field experiment was conducted using different doses of nitrogen (0, 40, 80, and 120 kg ha⁻¹) and sulphur (0, 50 kg ha⁻¹). The results show that fertilisation with N and S had a significant effect on increasing the content and uptake of P and Si by phytomass in the phenostages studied. In general, as the N fertilisation dose increased, the yields of phytomass and grain increased. A beneficial effect of S on increases in green weight, straw, and spring wheat grain was found. A significant effect of N and S fertilisation on the growth of the Si:P ratio in individual parts of plants in the studied stages was also observed. A significant positive correlation between P and Si content was proven, indicating that the two elements do not act antagonistically towards each other. In contrast, a negative correlation was observed between the P content in plants and their Si uptake. Si is taken up more strongly by plants under conditions of N and S fertilisation, as evidenced by the increase in the Si:P ratio and the fact that plants accumulated on average 3.5 times more Si than P. The highest Si content was found in the green parts of plants in the BBCH 30–31 and BBCH 55–59 stages, while in BBCH 89–92, straw had nearly half that amount and grain contained a thousand times less silicon. Full article

Postharvest losses of fruits and vegetables are a global problem that directly affect food security, the economy, and the environment. These losses are mainly associated with fungal diseases during storage. Due to the limitations of synthetic fungicides, including the development of resistance and risks to human health, there is growing interest in sustainable disease control strategies. This scoping review analyzes the potential of the yeast Metschnikowia pulcherrima as a biocontrol agent for postharvest phytopathogens, based on the scientific literature published between 2014 and 2026. The reviewed studies identify several antagonistic mechanisms, including competition for nutrients and space, the production of organic volatile compounds, hydrolytic enzyme activity, biofilm formation, and the induction of resistance in fruits. In vitro and in vivo assays show that M. pulcherrima effectively reduces postharvest disease incidence and severity caused by certain fungi. Furthermore, its synergistic effect when combined with emerging technologies is notable. The results highlight its potential as a sustainable alternative to synthetic fungicides, although further studies are needed for large-scale commercial application. Full article

Acibenzolar-S-methyl (ASM), a salicylic acid (SA) analog, and jasmonic acid (JA) are chemical inducers of plant defenses, yet crosstalk between SA- and JA-associated pathways may result in antagonistic outcomes. Here, we assessed how ASM and JA, applied alone or in combination, are associated with rice blast severity and defense-related responses in an upland rice cultivar. Plants of rice (Oryza sativa L., cv. Primavera) were treated with JA, ASM or JA + ASM and subsequently challenged with Magnaporthe oryzae. ASM treatment was associated with reduced leaf blast severity (LBS), whereas JA treatment was associated with increased LBS. Antagonistic outcomes were observed in the combined treatment: LBS in JA + ASM plants was higher than in ASM-treated plants but lower than in JA-treated plants. Lipoxygenase (LOX) activity was induced by JA and positively correlated with LBS, indicating that higher LOX activity aligned with greater susceptibility under the tested conditions. In contrast, ASM-treated plants showed higher peroxidase (POX) activity, which was associated with lower LBS. Disease outcomes were also linked to secondary defense metabolism and phenylpropanoid-related components, including phenylalanine ammonia-lyase (PAL), salicylic acid (SA) and phenolic compounds (PC). Overall, these results provide an integrated biochemical profile of how ASM, JA and their combination are associated with contrasting blast outcomes in upland rice, consistent with antagonistic interactions between JA- and SA-associated defense responses. These findings may inform the use of defense inducers and the interpretation of defense markers in upland rice systems where blast management is a major constraint. Full article

Semantic communications have emerged as a key paradigm for intelligent sixth-generation (6G) wireless networks, which aim to convey the meaning of information rather than accurate bit sequences. However, in open-space low Earth orbit (LEO) satellite links, the broadcast nature and wide beam coverage expose semantic transmissions to severe eavesdropping risks. This paper establishes a unified theoretical and algorithmic framework for secure semantic downlink transmission in satellite networks. In particular, we first develop an integrated mathematical model that couples the semantic representation process, physical-layer satellite propagation characteristics, and information-theoretic secrecy into a single analytical formulation. By defining a joint semantic security cost function, the antagonistic trade-off between semantic fidelity and secrecy capacity is quantitatively characterized under realistic power, beamforming, and propagation constraints. To balance semantic fidelity and information secrecy, a reinforcement-learning-based optimization framework is proposed, wherein an actor–critic agent learns optimal power allocation and semantic weighting strategies through continuous interaction with the environment. This learning-based optimization approach enables autonomous control without requiring explicit channel distribution knowledge or offline parameter tuning. Extended simulation results show that the proposed approach consistently enhances both semantic fidelity and secrecy performance compared with conventional power-control schemes and demonstrate its potential as a foundational architecture for secure and intelligent semantic communications in next-generation satellite networks. Full article

Osteocytes, once viewed mainly as passive bone-embedded cells, are now recognized as active regulators of the metastatic bone niche. Emerging evidence indicates that these cells integrate mechanical, inflammatory, and tumor-derived cues to influence metastatic seeding, dormancy, reactivation, and lesion progression in bone. This review synthesizes current understanding of osteocyte contributions to skeletal metastasis. We discuss core signaling axes, including osteocyte-derived RANKL/OPG balance, Wnt antagonists (sclerostin/DKK1), mechanotransduction pathways (Piezo1 signaling and connexin-43 hemichannels), and osteocyte paracrine mediators (extracellular vesicles and senescence-associated factors), and examine how each axis modulates tumor cell dormancy, osteolysis, or osteoblastic progression. We then review translational strategies targeting osteocytes, recent preclinical and clinical insights. Emerging biomarkers (e.g., serum sclerostin, DKK1, bone turnover markers) and immune–skeletal imaging approaches are also considered. Controversies, including the paradoxical effects of sclerostin blockade and the identity of in vivo RANKL sources, are discussed. Finally, we outline key knowledge gaps and propose endpoints for future trials. In summary, an osteocyte-centric perspective reveals novel targets and strategies for managing bone metastases, guiding future translational research. Full article

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide, with blast TBI (bTBI) particularly affecting military personnel and individuals exposed to explosive environments, yet there are no available curative treatments to date. While adrenergic receptor antagonists have shown promise in reducing neuroinflammation and improving TBI mortality rates, systemic administration of these drugs can have deleterious effects including bradycardia and hypotension. Here, we introduce a polymeric nanoparticle system for the delivery of adrenergic receptor antagonists, which allows for size-based targeting of the injured blood–brain barrier (BBB). These nanoparticles consist of chitosan-coated polylactic co-glycolic acid encapsulating the β-adrenergic receptor antagonist propranolol and/or the α-adrenergic receptor antagonist phenoxybenzamine. Particles designed with a 200 nm hydrodynamic diameter showed a 20–24% increase in permeability on an in vitro contact co-culture BBB model exposed to a 23 or 35 PSI acoustic blast when compared to uninjured controls, whereas 100 nm particles show no difference, suggesting blast injury induces BBB damage that enables the accumulation of larger particles. Treatment of blast-injured human brain microvascular cells with our nanoformulation reduced extracellular inflammatory cytokine levels and reduced the expression of pro-inflammatory markers in microglia. Moreover, these particles mitigated the upregulation of extracellular TNFα induced by free phenoxybenzamine in injured and uninjured microglia, suggesting nanoparticle drug encapsulation can reduce adverse drug reactions in the brain. Together, these findings provide proof-of-concept for size-based targeting and the potential anti-inflammatory effects of CS-PLGA nanoparticles containing adrenergic receptor antagonists for treatment of TBI and bTBI. Full article

Cadmium (Cd) contamination in paddy soils threatens rice production and food safety. This study investigated the effects of manganese (Mn)-enriched biochar on soil Cd immobilization and Cd accumulation in rice using a pot experiment with Cd-contaminated soil. Unenriched biochar and Mn-enriched biochar prepared from rice straw were applied at two rates (0.5% and 1.0%). Both biochar types significantly increased soil pH and organic matter and promoted the transformation of Cd from labile fractions to more stable residual forms, thereby reducing Cd bioavailability. As a result, Cd accumulation in rice tissues, including straw and brown rice, was significantly reduced. Correlation analysis further indicated that increased soil pH was associated with reduced Cd mobility and plant uptake. Mn-enriched biochar markedly increased Mn accumulation and uptake efficiency in rice while decreasing Cd uptake efficiency, indicating a strong antagonistic interaction between Mn and Cd in the soil–plant system. Notably, a low application rate of Mn-enriched biochar (0.5%) achieved Cd reduction effects comparable to those of a higher dose of unenriched biochar (1.0%). These results suggest that Mn-enriched biochar is an effective and potentially cost-efficient strategy for reducing Cd bioavailability in paddy soils and mitigating Cd accumulation in rice. Full article

The potential of Trichoderma nordicum (Hypocreales, Ascomycota), a recently described species, for antagonism and use in the biocontrol of oomycete-caused plant diseases is unknown. Trichoderma is a well-known genus for containing microbial antagonists and biocontrol agents. The T. nordicum in this study was isolated from decomposing wood, and rpb2 and tef1 barcode sequencing demonstrated that the isolates were a match to the reference T. nordicum and T. nigricans strains. Since T. nordicum was described before T. nigricans, the isolates were assigned to T. nordicum, although taxonomic uncertainty between these species requires future clarification. In dual-culture confrontation assays, T. nordicum overgrew five economically important oomycete plant pathogens (Phytophthora capsici, P. sojae, Pythium aphanidermatum, P. myriotylum, and Globisporangium ultimum). The inability to recover viable P. aphanidermatum and P. capsici from the parts of the plate overgrown by T. nordicum, coupled with protease and endo-cellulase activities, correlates with T. nordicum having antagonistic abilities. Inoculation with T. nordicum preventively reduced the levels of cucumber seedling damping-off caused by P. aphanidermatum by up to 70%. The T. nordicum biocontrol effects against pepper blight caused by P. capsici were greater than 80%, compared to an autoclaved T. nordicum spore control. T. nordicum could also significantly promote the growth of pepper, with plant weight increased by up to 40%, compared to an autoclaved-spore control. In contrast, T. nordicum could not be used to control Pythium soft rot of ginger caused by P. myriotylum, even though P. myriotylum was overgrown by T. nordicum, suggesting host- or pathosystem-specific factors influence biocontrol efficacy. In summary, T. nordicum is a promising biocontrol agent for use in the control of pepper blight caused by P. capsici, and also has potential for use in the control of other oomycete-caused plant diseases in vegetable production systems. Full article

Lead (Pb) and cadmium (Cd) are common environmental pollutants. Our previous population study revealed a significant positive association between Pb and Cd exposure and the micronuclei frequency among lead smelting workers. However, the underlying mechanisms remain unclear. In this study, human lymphoblastoid TK6 cells were used to investigate the genotoxicity and its mechanisms induced by individual or combined exposure to Pb and Cd. Our results showed that Pb and Cd exposure, alone or in combination, triggered oxidative stress, as evidenced by reduced antioxidant enzyme activity (GSH, SOD and CAT) and increased content of ROS and GSSG. Both metals induced pronounced DNA damage, as shown by elevated Tail DNA% in the Comet assay and γ-H2AX fluorescence intensity. Furthermore, Pb and/or Cd exposure caused inhibition of the DNA repair proteins, including BRCA1, CtIP, RAD52, and XRCC2, indicating impaired DNA repair capacity; and upregulated Bax expression and the Bax/Bcl-2 ratio and Caspase-3 with downregulation of Bcl-2. Notably, Pb and Cd co-exposure produced an antagonistic effect, modulating oxidative stress indicators, cell-cycle arrest, DNA damage markers, DNA repair and apoptosis-related proteins. These findings demonstrate that Pb and Cd induce oxidative stress, DNA damage, inhibition of DNA repair, and apoptosis in TK6 cells. Our study provides new insights into the mechanisms of heavy metal combined exposure–induced genotoxicity and identifies potential molecular targets for intervention. Full article