Search Results (14,985)

Background/Objectives: Spotty liver disease (SLD), caused by Campylobacter hepaticus, is an emerging disease that leads to substantial production losses in the egg industry. The shift toward antibiotic-free and cage-free production systems has further intensified the impact of SLD. The current control measures largely rely on autogenous killed vaccines; however, their use is constrained by the slow and fastidious growth of C. hepaticus and inconsistent efficacy. To overcome these limitations, this study aimed to identify immunogenic mimotopes as vaccine candidates and express them on the surface of an avian pathogenic Escherichia coli (APEC) vector. Methods: To identify immunogenic mimotopes, Ph.D.-12 phage display peptide library was screened using the hyperimmune serum raised against killed whole-cell C. hepaticus in specific pathogen-free chickens. Subsequently, the outer membrane protein C (OmpC) of E. coli was used as a scaffold for constructing a surface display library. A single restriction site, PstI, located in the seventh external loop of OmpC, was strategically utilized to insert each 12-amino-acid mimotope with a six-histidine (6xHis) tag sequence at its N-terminus, generating ompC + mimotope fusion constructs. These constructs were cloned into the inducible expression vector pTrc and electroporated into an E. coli DH5α ∆ompC strain, which lacked ompC. The surface expression of the mimotopes was confirmed in vitro. The verified ompC + mimotope constructs were subsequently subcloned into the pYA3422 constitutive expression vector and electroporated into the APEC PSUO78 ∆aroA ∆asd vaccine vector strain. A chicken vaccination–challenge trial was conducted using nine groups of chickens, including an unvaccinated challenged control and an unvaccinated–unchallenged negative control. Each experimental group received a mixture of two recombinant E. coli strains carrying different mimotopes at a dose of 1 × 10⁹ CFU, which were administered orally twice at 16 and 18 weeks of age. Results: Fourteen immunogenic mimotopes corresponding to 13 different C. hepaticus proteins were identified as potential vaccine candidates. The expression of these mimotopes on the surface of the E. coli was successfully demonstrated using the OmpC-mediated surface display system. Of the 14 mimotopes tested, two flagellar-related peptides and one major outer membrane protein (MOMP)-derived peptide elicited significant immune responses and conferred protection against the C. hepaticus challenge. Conclusions: We successfully developed a functional E. coli surface display system that was capable of expressing 12-amino-acid mimotopes of C. hepaticus, providing a robust platform for evaluating vaccine candidates against SLD. Immunogenicity and efficacy studies in chickens demonstrated that three identified mimotopes conferred protection against C. hepaticus colonization of the bile and liver. Future in vivo investigations are necessary to develop and evaluate the immunogenicity and protective efficacy of a multivalent mimotope vaccine consisting of three identified mimotopes against both C. hepaticus and APEC, utilizing the ΔaroA Δasd APEC PSU078 strain as the vaccine vector. Full article

Endometriosis affects approximately 10% of reproductive-age women and is associated with genomic instability; however, the contribution of specific DNA repair deficiencies remains poorly understood. This study investigated the expression and function of GEN1, a Holliday junction resolvase critical for homologous recombination, in patient-derived endometrial epithelial organoids (EEOs). Endometrial tissue was obtained by pipelle biopsy from women with laparoscopically confirmed endometriosis (n = 3, stage III–IV) and controls without endometriosis (n = 3). GEN1 mRNA and protein expression were reduced in primary endometrial cells from endometriosis patients compared with controls (mRNA: 0.52 ± 0.14 vs. 1.00 ± 0.19, p = 0.05; immunofluorescence intensity: 0.54 ± 0.18 vs. 1.00 ± 0.22, p = 0.05). Patient-derived EEOs from the endometriosis group showed trends toward lower formation efficiency (18.4 ± 5.6% vs. 25.2 ± 6.8%, p = 0.10) and reduced mean diameter (124.6 ± 34.2 vs. 155.8 ± 32.6 µm, p = 0.10). RNA interference (RNAi)-mediated GEN1 knockdown reduced proliferation in both groups, with a more pronounced effect in endometriosis-derived EEOs (49.7% vs. 39.5% reduction, p = 0.05). Endometriosis-derived EEOs exhibited elevated baseline γH2AX (phosphorylated histone H2AX) immunofluorescence compared with controls (2.32 ± 0.44 vs. 1.00 ± 0.28, p = 0.05), indicating increased DNA double-strand break accumulation. Furthermore, GEN1 knockdown directly increased γH2AX intensity in both groups, with endometriosis-derived EEOs showing a greater absolute increase (Δ1.26 vs. Δ0.72). To our knowledge, this study provides the first organoid-based evidence that GEN1 is downregulated in endometriosis and functionally linked to impaired proliferation and elevated DNA damage, suggesting a potential contribution of homologous recombination dysregulation to endometriosis pathogenesis. Full article

Effective oral interventions for alcohol-induced metabolic stress and liver injury remain limited. Pre-absorptive gastrointestinal alcohol handling is gaining interest as a non-pharmacological strategy to reduce hepatic burden. In this study, we developed a formulation-integrated, food-compatible lyophilized recombinant whole-cell catalyst based on Escherichia coli Nissle 1917 engineered to express alcohol dehydrogenase and acetaldehyde dehydrogenase. Rather than focusing exclusively on strain-level genetic modification, the engineered cells were protected by lyophilization combined with a food-grade chitosan–alginate layer-by-layer coating, forming an artificial cell wall designed to enhance survivability during oral delivery. The formulation resisted simulated gastric acid, sodium taurocholate, and ethanol, retained enzymatic activity after storage, and demonstrated formulation stability. In alcohol-exposed mice, oral administration reduced blood ethanol and acetaldehyde levels, improved liver biochemical parameters, attenuated hepatic steatosis, and partially restored oxidative stress indicators. Integrated multi-omics analyses indicated coordinated gut-associated metabolic and inflammatory responses to alcohol and intervention, rather than a single dominant pathway. These findings provide hypothesis-generating evidence; causality remains to be established. Overall, this study demonstrates a proof-of-concept, food-compatible lyophilized recombinant whole-cell catalyst that integrates enzymatic function with formulation stability and gastrointestinal resilience, highlighting an applied, food-compatible microbial framework for exploring alcohol-related metabolic stress. Full article

Background/Objectives: Epstein–Barr virus (EBV) is associated with a subset of gastric carcinomas characterized by latency programs that promote survival of infected cells. EBV-encoded BamH I A rightward transcript (BART) microRNAs contribute to apoptosis resistance in infected epithelial cells. This study investigated whether dasatinib, a Src family kinase (SFK) inhibitor, selectively targets EBV-positive gastric epithelial cells and examined the molecular mechanisms underlying this effect. Methods: EBV-positive and EBV-negative gastric epithelial cell models were analyzed to evaluate cell viability, apoptosis induction, signaling pathways, and viral gene regulation. BART miRNA expression was quantified by RT-qPCR, and promoter activity was examined using luciferase reporter assays. Downstream target gene expression was analyzed at both the transcript and protein levels. Recombinant EBV lacking BZLF1 or LMP2A was used to assess the contributions of lytic activation and LMP2A-associated signaling. Results: Dasatinib preferentially reduced viability and induced apoptosis in EBV-positive gastric epithelial cells compared with EBV-negative counterparts. Treatment suppressed phosphorylation of Src and ERK and reduced expression of the anti-apoptotic proteins BCL-xL and MCL1. Apoptosis was also observed in cells infected with LMP2A-deficient EBV, suggesting that the effect cannot be fully explained by inhibition of LMP2A-associated signaling. Dasatinib inhibited BART miRNA promoter activity and reduced pri-, pre-, and mature miR-BART levels, accompanied by increased expression of pro-apoptotic target genes including CASZ1a, OCT1, ARID2, TP53INP1, and DAB2. In parallel, dasatinib suppressed BZLF1 promoter activity without evidence of lytic reactivation. Conclusions: Dasatinib promotes apoptosis in EBV-positive gastric epithelial cells in association with coordinated suppression of SFK signaling and EBV-encoded BART miRNA expression, accompanied by derepression of pro-apoptotic cellular genes. These findings reveal a previously underappreciated vulnerability of EBV-positive epithelial cells and suggest that targeting host kinase signaling pathways that regulate viral microRNAs may represent a potential therapeutic strategy for EBV-associated malignancies. Full article

Alchemilla alpina L. (Rosaceae), belongs to a genus well recognized in traditional medicine for treating gynecological disorders and hormonal imbalance; however, the specific bioactivity of A. alpina itself remains poorly characterized. This study aimed to elucidate the phenolic composition and the biological potential of the methanolic (MeOH) extract of A. alpina. LC–MS/MS analysis identified 39 phenolic compounds, with rutin, catechin, kaempferol-3-O-glucoside, and caffeic acid being the dominant constituents. The extract exhibited high total phenolic and flavonoid contents, consistent with strong antioxidant capacities. It demonstrated notable α-glucosidase and acetylcholinesterase inhibitory activities, indicating its potential relevance for metabolic and neurodegenerative disorders. The extract effectively reduced AAPH-induced ROS levels in MRC-5 fibroblasts, indicating cytoprotective and antioxidative effects. The cytotoxicity toward cervical cancer cells HeLa and ovarian cancer cells A2780 was moderate and concentration dependent. A yeast-based fluorescent screen revealed a strong and selective binding affinity toward estrogen receptor α (ERα) and selective inhibition of human recombinant AKR1C3 (59.5%), without affecting AKR1C4. Additionally, high COX-1/COX-2 inhibition (>70%) supported its anti-inflammatory potential. Collectively, these findings provide the first integrated evidence of A. alpina’s phenolic richness and multifunctional bioactivity, scientifically supporting its potential in managing hormone-dependent and oxidative stress-related disorders. Full article

The development of efficient, stable, and sustainably fabricated photocatalysts for solar-driven hydrogen evolution remains a critical challenge in the field. Herein, we report a novel green coprecipitation strategy to synthesize calcium-doped zinc oxide (Ca-ZnO) nanosheets, utilizing cactus juice as a natural, multifunctional medium for the coprecipitation process. This method enables the in situ, tunable incorporation of 3–7% Ca²⁺ ions into the wurtzite ZnO lattice without the use of harsh chemical reagents. Comprehensive characterization confirms that Ca²⁺ substitutionally replaces Zn²⁺, which preserves the intrinsic crystal structure of ZnO well while inducing the formation of uniform nanosheet morphology. This doping strategy effectively modulates the electronic band structure, progressively narrowing the bandgap from 3.19 eV to 2.90 eV and significantly enhancing visible-light absorption. Crucially, the incorporation of Ca²⁺ also generates oxygen vacancies, which serve as efficient electron traps to suppress photogenerated charge carrier recombination. The optimized 5%Ca-ZnO photocatalyst demonstrates a favorable hydrogen evolution rate of 889 μmol·g⁻¹·h⁻¹ under full-spectrum irradiation, with stability, retaining 94.8% of its activity after four cycles. This work not only provides a high-performance material but also establishes a generalizable, sustainable paradigm for the design of advanced semiconductor photocatalysts. Full article

Poly(ADP-ribose) polymerase inhibitors (PARPi) have reshaped therapy for advanced prostate cancer, yet durable benefit remains concentrated in BRCA1/2-altered tumors, especially BRCA2, and most responders eventually relapse. Here, we frame PARPi response and resistance through a unifying model in which DNA damage response (DDR) rewiring (e.g., homologous recombination repair (HRR) restoration, fork protection, checkpoint tolerance, and altered drug handling) converges with treatment-induced dormancy and quiescent therapy-tolerant residual states that sustain minimal residual disease (MRD) under androgen receptor pathway inhibition (ARPI) and PARP blockade. We synthesize clinical and translational evidence for PARPi monotherapy and PARPi-based combinations across disease states. In first-line metastatic castration-resistant prostate cancer (mCRPC), PARPi plus ARPI consistently prolongs radiographic progression-free survival, with the greatest benefit in HRR-altered tumors, and emerging overall-survival signals in selected subgroups. In later-line settings, monotherapy activity is most robust in BRCA2-mutated disease, whereas non-BRCA HRR alterations show heterogeneous and often modest responses, underscoring the need for biomarkers beyond gene panels. We also discuss combination strategies with DDR-targeting agents, radioligand therapies, and immunotherapy, and summarize ongoing phase III programs in metastatic castration-sensitive prostate cancer (mCSPC). Finally, we outline practical considerations for biomarker-informed patient selection, monitoring, sequencing, and toxicity management, with particular emphasis on intercepting MRD and resistance evolution. Full article

Background/Objectives: Hand, foot, and mouth disease (HFMD) is a major public health concern primarily caused by human enterovirus A71 (EV-A71), coxsackievirus A16 (CVA16), coxsackievirus A6 (CVA6), and certain coxsackievirus B serotypes. Currently available EV-A71 vaccines lack cross-protective efficacy against other serotypes, highlighting the urgent need for multivalent and broadly effective enterovirus vaccines. Methods: Immunoinformatics approaches were used to predict highly immunogenic B-cell and T-cell epitopes, which were assembled to construct a novel multivalent epitope vaccine, rCV-A3V, followed by in silico validation. Recombinant protein expression was confirmed by Western blotting and immunofluorescence assays. The immunogenicity was evaluated in Balb/c mice following intranasal immunization. Results: A preliminary safety evaluation demonstrated that the rCV-A3V vaccine was well tolerated in the mouse model, with no abnormal changes in body weight observed after immunization. In addition, the target protein was successfully expressed. Intranasal immunization induced a strong Th1-biased immune response, robust serum neutralizing and IgG antibody responses, and pronounced mucosal immunity, including elevated sIgA and IgG levels in nasal lavage fluid, sIgA in feces, and substantial sIgA responses in milk. Dominant epitope peptides were also identified. Conclusions: The intranasal live attenuated rCV-A3V vaccine successfully induced humoral, mucosal, and cellular immune responses against EV-A71, CVA16, CVA6, and CVB3, demonstrating broad immunogenicity. These findings provide experimental evidence supporting its potential as a candidate vaccine for HFMD. Full article

As a non-invasive mucosal immunization strategy, intranasal vaccines are highly promising for preventing respiratory infectious diseases. Among them, recombinant subunit vaccines represent a safe and ideal option, as they induce targeted mucosal immunity without the safety risks associated with live-vectored or nucleic acid vaccines. However, nasal mucosal defenses rapidly clear antigens before immune activation, limiting protective efficacy. Therefore, intranasal vaccine adjuvants—key regulators of immune response intensity, duration, and type—are essential to overcome mucosal tolerance and improve immunogenicity. Based on a systematic search and analysis of 127 peer-reviewed articles (2010–2026) in PubMed, Web of Science, and Embase, this study comprehensively summarizes the mechanisms, applications, and limitations of existing and candidate adjuvants for intranasal vaccines. This review systematically categorizes and discusses the nasal mucosal barrier, major adjuvant types (e.g., pattern recognition receptor agonists, cytokine adjuvants, and carrier adjuvants), and their mechanisms of action. It also identifies key bottlenecks: insufficient mucosal targeting, inconsistent global safety evaluation standards for adjuvants, and interference from pre-existing antibodies in humans. Furthermore, this review highlights future development directions, including biomimetic adjuvants, pH-responsive nanoadjuvants, and thermostable vaccine formulations. This systematic review clarifies key scientific and technical barriers in intranasal vaccine adjuvant development. The findings provide valuable references for advancing the translation of intranasal vaccines from emergency countermeasures to routine, accessible preventive tools for respiratory infectious diseases. Full article

Background: Recombinant human growth hormone (rhGH) replacement therapy, administered to children with growth hormone deficiency (GHD), exerts pleiotropic effects on growth, metabolism, and tissue functions. Extracellular vesicles (EVs) are emerging mediators of inter-organ communication, but the effects of rhGH therapy on EV release in humans have not yet been investigated. Methods: In a preliminary prospective clinical study, children with GHD (n = 10; F/M = 5/5; age: 11.0 ± 2.7 years) were treated with rhGH for 6 months. Plasma samples were collected at baseline (T0) and after treatment (T6) to characterize the size distribution and tissue-derived composition of circulating EVs. Total EVs and EV subpopulations derived from monocytes/macrophages (CD14+), adipose tissue (FABP+), skeletal muscle (SCG+), endothelium (CD62E+), and platelets (CD42A+) were analyzed. Clinical, auxological/auxometric, and biochemical/metabolic parameters were assessed in parallel. Statistical methods included longitudinal analyses, interaction models, and adjustments for relevant covariates, including insulin-like growth factor 1 (IGF-1) and osteocalcin. Results: After 6 months of rhGH therapy, significant improvements in height velocity (cm/year and SDS) were observed, accompanied by increased circulating IGF-1 and osteocalcin levels. Hormone therapy induced no size-dependent changes in (total) EVs. Significant increases in CD14+ and FABP+ EVs were observed after treatment, without affecting the other tissue-derived EVs. Interaction analyses revealed that children with more severe GHD exhibited a stronger vesiculogenic response to rhGH. Furthermore, specific tissue-derived EVs were associated with metabolic/biochemical and auxological/auxometric parameters, including lipids, insulin resistance, and growth-related measures. Conclusions: When administered for six months, rhGH therapy seems to selectively change tissue-derived composition of circulating EVs in GHD children, particularly those derived from immune cells and adipose tissue. These preliminary findings suggest that EVs might represent an adjunctive component of GH-dependent inter-organ communication and might serve as biomarkers of treatment response and disease severity in pediatric endocrinology. Full article

Mixograph properties represent important quantitative traits that are controlled by multiple genes and influenced by environmental factors. In this study, we conducted quantitative trait locus (QTL) mapping for key Mixograph paraments using a recombinant inbred line (RIL) population derived from a cross between Yangxiaomai and Zhongyou 9507. Based on a high-density genetic map, six stable QTLs were identified on chromosomes 1A, 1B, and 1D across four environments, with individual phenotypic variation explained, ranging from 2.26 to 28.70%. Among these, QTh.ahau-1A, QMt/QPa.ahau-1B, and QTw.ahau-1D.1 are potentially novel loci. Furthermore, four functional Kompetitive Allele-Specific PCR (KASP) markers were developed based on tightly linked SNPs and validated in 110 advanced breeding lines, confirming their significant association with the target traits and utility for marker-assisted selection (MAS). Additionally, six candidate genes were predicted, which encoded proteins such as a hydroxyproline-rich glycoprotein, a CCCH-type zinc finger protein, protease, kinase, a phosphoglucan water dikinase, and a TRP-like family protein. Collectively, these findings provide valuable genetic loci, functional molecular markers, and candidate gene resources for improving wheat processing quality through MAS-based breeding. Full article

Toxoplasma gondii (T. gondii) is an intracellular parasite known to modulate host immunity and cellular signaling, raising interest in its potential influence on cancer biology. A systematic review was conducted to evaluate experimental evidence on the antitumor or pro-tumor effects of T. gondii infection and parasite-derived antigens and to categorize the underlying mechanisms. PubMed was searched through 9 September 2024, and 54 eligible experimental studies were included (41 in vivo, 10 in vitro, and three combined). Forty-six studies reported antitumor effects, two pro-tumor effects, one stage-dependent divergent effects (acute infection/antitumor vs. chronic infection/pro-tumor), and five highlighted T. gondii-associated cancer-pertinent signaling pathways. Antitumor effects were observed following acute infection and exposure to parasite antigens, certain recombinant proteins, and exosomal microRNA miR-155-5p. Dominant mechanistic categories included activation of innate and adaptive immunity and reversal of tumor microenvironment immunosuppression (notably Th1-driven IL-12/IFN-γ responses, antitumor M1 macrophage polarization), induction of apoptosis, anti-angiogenesis, molecular mimicry and modulation of cancer-pertinent pathways. Conversely, pro-tumor effects were seen with chronic infection and exposure to ROP18 effector protein and miR-21. Future translational research should focus on rigorous evaluation of the safety and efficacy of attenuated non-replicating T. gondii strains and/or select recombinant antigens for potential cancer T. gondii-based immunotherapy. Full article

High-efficiency Ovum Pick-Up (OPU) and in vitro embryo production (IVP) are critical for the genetic improvement of high-value Wagyu cattle. However, oxidative stress and mitochondrial dysfunction during oocyte maturation remain major bottlenecks limiting blastocyst yield. This study investigated the role of inhibin in Wagyu oocyte competence through two independent proof-of-concept approaches. In the in vivo active immunization model, thirty Wagyu donors were immunized with a recombinant inhibin protein (INHA group), resulting in a significant increase in the number of recovered cumulus–oocyte complexes (COCs) (461 vs. 279, p < 0.05) and the proportion of high-quality oocytes compared to controls. Oocytes from the INHA group exhibited improved cytoplasmic maturation and mitochondrial function, characterized by higher membrane potential (ΔΨm, JC-1 ratio: 1.55 ± 0.06 vs. 0.83 ± 0.08, p < 0.05), elevated ATP content (2.35 ± 0.07 vs. 1.63 ± 0.03 pmol/oocyte, p < 0.05), and increased NADPH levels. Furthermore, the INHA group showed significantly reduced reactive oxygen species (ROS) accumulation and an increased GSH/GSSG ratio (8.48 ± 0.18 vs. 6.25 ± 0.09, p < 0.05), indicating restored redox homeostasis. Independently, in the in vitro anti-inhibin antibody (AIA) supplementation model, AIA supplementation during oocyte maturation significantly improved the nuclear maturation rate (92.96% ± 1.04%), blastocyst formation rate (56.63% ± 2.36%), and total cell number compared to controls (p < 0.05). Notably, AIA-derived blastocysts achieved a significantly higher pregnancy rate (78.65% ± 1.57%) following transfer. Collectively, these findings demonstrate that targeting inhibin mitigates oxidative injury and stabilizes mitochondrial bioenergetics, providing two distinct, physiology-based strategies for optimizing Wagyu oocyte yield and embryo production. Full article

Lactic acid bacteria (LAB) are pivotal microorganisms in the food industry. Current approaches for functional gene validation and trait improvement in LAB primarily rely on traditional gene editing and homologous recombination techniques. These methods are often cumbersome, inefficient, and time-consuming, hindering the rapid and precise customization of strains. This limitation has, to some extent, constrained the rapid selection and industrial application of functional LAB strains. The engineering of LAB through gene editing technologies has significantly advanced both fundamental and applied research. Among these, CRISPR/Cas gene editing has successfully achieved precise modification of multiple genes in various LAB species. Compared to conventional methods, it offers superior editing efficiency and lower operational costs, opening new avenues for functional gene identification and genetic improvement in LAB. However, the application of exogenous CRISPR/Cas systems in LAB faces technical challenges such as high off-target rates, chromosomal abnormalities, and cytotoxicity. The development of endogenous CRISPR/Cas-based editing tools for LAB provides novel pathways for precise regulation, rational design, and flexible application. This paper first outlines the structural components and mechanistic principles of CRISPR/Cas gene editing tools. It then explores the research progress and applications of both endogenous and exogenous CRISPR/Cas systems in LAB. Finally, it provides an outlook on the future application of CRISPR/Cas gene editing technology in LAB, offering a reference for its implementation in this field. The advent of gene editing technologies has significantly propelled functional gene validation and trait improvement in lactic acid bacteria (LAB), thereby advancing both fundamental research and industrial applications. Notably, the CRISPR/Cas system has emerged as a transformative tool enabling precise genetic modification in diverse LAB species, offering marked improvements in editing efficiency and cost reduction relative to conventional approaches. CRISPR/Cas-based editing strategies in LAB are broadly classified into exogenous and endogenous systems. Exogenous systems operate independently of the host’s native immune repertoire, conferring the advantages of broad strain applicability and high editing efficiency. These systems have been successfully deployed for functional gene characterization, metabolic pathway engineering, such as augmenting antimicrobial production, and probiotic safety enhancement via virulence gene deletion. Conversely, endogenous systems leverage the intrinsic CRISPR/Cas machinery of LAB, offering superior biocompatibility and minimized off-target risks. Notable applications include precise gene knockout and integration using the native Type I-E system in Lacticaseibacillus paracasei. This review provides a concise overview of CRISPR/Cas system architecture and mechanisms, followed by a systematic synthesis of research progress and applications for both exogenous and endogenous systems in LAB. Finally, future directions are outlined to guide the continued development and application of CRISPR/Cas technologies in this field. Full article

To identify chitinase genes from the genome of the mycoparasitic Cladosporium sp. strain SYC23, bioinformatical analyses and real-time quantitative PCR (RT-qPCR) were employed to screen mycoparasitism-associated genes at 12, 24, 48, and 72 h post-induction with Aecidium pourthiaea rust spores. A total of eight chitinase genes were identified from SYC23 via bioinformatics analysis and designated CaChi34, CaChi40, CaChi45, CaChi67, CaChi82, CaChi92, CaChi93, and CaChi286 based on sequence and phylogenetic analyses. Analysis of the chitinase protein sequence characteristics revealed molecular weights ranging from 33.86 to 286.03 kDa and theoretical isoelectric points from 4.48 to 7.7. All CaChi genes contained the conserved GH18 domain, and promoter analysis showed that each harbored MYB-binding sites and pathogen-responsive elements. Mycoparasitism-related sequence clustering analysis indicated that the chitinase sequences of SYC23 shared the closest phylogenetic relationship with those from Trichoderma sp. RT-qPCR results following rust spore induction showed that five CaChi genes reached their highest expression levels at 24 h post-induction, CaChi45 was most highly expressed at 72 h post-induction, CaChi93 was continuously upregulated, and CaChi82 was continuously downregulated throughout the induction period. His-tagged recombinant CaChi93 protein was purified from E. coli and characterized. The results demonstrate that the enzymatic activity of CaChi93 was 0.929 U/mg, with optimal reaction conditions at 65 °C and pH 7. Treatment of A. pourthiaea rust spores with the recombinant CaChi93 chitinase confirmed that CaChi93 could effectively dissolve rust spore walls. In conclusion, this study confirms that the mycoparasitic Cladosporium sp. strain SYC23 can secrete chitinase to degrade the rust spore wall and induce spore death, thereby providing novel gene resources and a theoretical basis for the biological control of A. pourthiaea. Full article