Search Results (676)

Cotton is an economically important cash crop severely affected by Verticillium wilt caused by Verticillium dahliae. Secreted cell-wall-degrading enzymes act as key virulence factors of this pathogen, yet the biological function of glucan 1,3-β-glucosidase remains largely uncharacterized. The gene VDAG_02814 (designated Vdbgl1) was previously found to be strongly induced during host infection. Here, combined approaches including gene knockout, host-induced gene silencing (HIGS), and transcriptomic analysis were utilized to characterize the function of Vdbgl1. The results showed that Vdbgl1 deletion retarded colony growth on PDA medium by 20.1–21.6%, decreased conidial yield by 20.2–46.7%, lowered spore germination rate by 30.7–32.9%, and weakened utilization of diverse carbon sources by 5.0–14.9%. The ΔVdbgl1 mutants also exhibited significantly increased sensitivity to cell wall-perturbing, osmotic, and membrane-damaging agents. Additionally, the ΔVdbgl1 mutants exhibited reduced disease index by approximately 19.1–27.7% and decreased fungal biomass by 42.7–61.8% in cotton; consistently, HIGS-mediated silencing of Vdbgl1 reduced the disease index by 25.7% and 26.7% and decreased fungal biomass by 48.1–71.5%. Transcriptome profiling of cotton roots infected by the ΔVdbgl1 mutant and the wild-type strain revealed 1007 down-regulated genes enriched in carbohydrate metabolism, cell wall degradation, and energy pathways, including 27 carbohydrate-active enzyme genes and 58 genes encoding cysteine-rich secreted proteins. Collectively, these findings indicated that Vdbgl1 coordinates carbon utilization, cell wall remodeling, and stress responses to regulate fungal development and pathogenicity, representing a promising target for cotton Verticillium wilt control. Full article

Carbonic anhydrases (CAs) are a class of zinc-containing metalloenzymes widely present in the biological world, catalyzing the reversible hydration of CO₂ to form HCO₃⁻ and H⁺. These enzymes play essential roles in pH homeostasis, gas exchange, metabolic regulation, and virulence expression in pathogens. In fungi, CAs mainly belong to the α- and β-classes and have undergone extensive diversification during evolution. In plant pathogenic fungi, the functions of CAs have extended beyond traditional metabolic roles, evolving into key “environmental adaptation and virulence regulatory factors.” This review takes Magnaporthe oryzae as a model organism and integrates recent advances in CA research across various microorganisms. It systematically summarizes the classification diversity, structural features, subcellular localization, and biological functions of fungal CAs. Particular emphasis is placed on the molecular profile, mitochondrial localization, physical interaction network, and multiple functional roles of the MoCA family members in conidial development, appressorium formation, oxidative stress response, HCO₃⁻ homeostasis, nitrogen metabolism, and mitochondrial energy metabolism. Based on these findings, this study proposes a multi-layered analytical framework integrating CA molecular characteristics, mitochondrial functional regulation, and fungal pathogenicity. It explores the potential of targeting fungal CAs for the development of novel selective fungicides and highlights key research directions, aiming to provide theoretical insights into plant-fungal interactions and innovative strategies for disease control. Full article

The transition toward reusable food packaging driven by European circular economy regulations introduces new food safety challenges related to microbial persistence and cross-contamination. GS-2 is a novel, food-safe antimicrobial formulation developed for use as a coating on reusable packaging materials. In the present study, the intrinsic antimicrobial activity of GS-2 was evaluated in liquid suspension against foodborne bacterial (Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica Agona) and fungal pathogens (Aspergillus flavus and Aspergillus niger), and the transcriptomic response of L. monocytogenes following sublethal GS-2 exposure was investigated. GS-2 exhibited concentration-dependent microbicidal activity, with strong reductions observed at ≥2.8–3.0% against bacterial strains and A. flavus, while A. niger demonstrated resistance. Among bacteria, L. monocytogenes showed the greatest sensitivity, with populations reduced below detection limits at 3% GS-2. To elucidate mechanistic responses, RNA sequencing was performed on L. monocytogenes exposed to sublethal GS-2 concentrations (0.1–1.0%). Transcriptomic analyses using discrete and continuous models revealed a pronounced adaptive stress response at 0.5% GS-2, characterized by coordinated upregulation of pathways involved in carbon, nitrogen, and nucleotide metabolism. At higher sublethal concentrations (1%), transcriptional profiles shifted toward growth arrest and cellular damage management. These findings support GS-2 as a promising antimicrobial for enhancing the microbial safety of reusable food packaging systems. Full article

Eucalyptus is an important timber species characterized by strong adaptability and rapid growth. However, adverse environmental conditions such as drought stress severely impact its growth and productivity. Arbuscular mycorrhizal (AM) fungi form beneficial symbiotic relationships with Eucalyptus root systems and significantly enhance plant stress tolerance. In this study, we identified 111 WRKY genes in Eucalyptus grandis and systematically characterized their physicochemical properties, phylogenetic relationships, gene structures, conserved motifs, synteny, and cis-acting elements. Notably, AM fungal symbiosis significantly enhanced the biomass, plant height, and root length of E. grandis seedlings under drought stress. Through integrated RNA-seq and qRT-PCR analyses, we identified 12 EgWRKY genes that responded to drought stress during AM fungal symbiosis, with their expression levels significantly elevated in AM-inoculated roots under drought conditions. These findings provide novel insights into the regulatory roles of EgWRKY genes in AM-mediated drought tolerance and establish a foundation for understanding the molecular mechanisms underlying WRKY-mediated stress responses in E. grandis. Full article

Pathogenic strains of Fusarium oxysporum are major soilborne fungal pathogens responsible for Fusarium wilt in tomato, leading to significant yield losses worldwide. This study evaluated the biocontrol potential of rhizospheric bacterial isolates from argan (Argania spinosa) and raspberry (Rubus idaeus) soils through an integrated approach combining in vitro screening, greenhouse validation, and phylogenetic analysis. A total of 27 bacterial isolates were screened for antifungal activity using dual culture assays, of which ten exhibited more than 50% inhibition of fungal growth. Selected isolates were further evaluated for volatile organic compound (VOC)-mediated inhibition. Despite strong in vitro performance for several isolates, greenhouse experiments revealed that antifungal activity in vitro was not a reliable predictor of in planta efficacy. Among the tested isolates, BSA25, BSA23, and BSF8 significantly reduced disease severity and incidence under greenhouse conditions, with BSA25 achieving the greatest suppression. In addition to disease control, certain isolates promoted plant growth under pathogen stress, indicating dual functionality as plant growth-promoting rhizobacteria (PGPR). Molecular identification based on 16S rRNA gene sequencing and phylogenetic analysis (Neighbor-Joining, Kimura 2-parameter) revealed that the isolates belong to PGPR-associated genera, including Bacillus and Pseudomonas, while also highlighting functional variability among closely related taxa. Overall, this study demonstrates that multi-trait evaluation, integrating mechanistic screening and in planta validation, provides a more reliable framework for selecting effective biocontrol agents. The identified isolates, particularly BSA25, represent promising candidates for further evaluation for sustainable management of Fusarium wilt in tomato production systems. Full article

Basidiomycetes produce a wide range of bioactive metabolites, yet the effects of fungal co-cultivation on phenolic composition and associated biological properties remain poorly understood. This study investigated the phenolic composition and antioxidant, photoprotective, and anti-tyrosinase activities of mycelial extracts obtained from four basidiomycetes cultivated either alone or in paired cultures. Phenolic compounds were characterized by HPLC, and the identified metabolites were further evaluated using target prediction, enrichment analyses, PASS prediction, ADME profiling, and toxicity assessment. Nine phenolic compounds were identified across ten cultivation systems. Catechin and syringic acid were detected only in selected paired cultures, indicating that fungal interactions altered phenolic composition. The highest antioxidant activities were observed for P. sanguineus and T. polyzona cultivated alone, while SPF reached 39 in P. ostreatus, T. polyzona, Lentinus + Pycnoporus, and Pycnoporus + Trametes. Tyrosinase inhibition reached 92.7% in the axenic culture of P. ostreatus and remained above 90% in selected co-cultures. Computational analyses identified enrichment of biological processes related to oxidative stress and UV responses, as well as pathways including PI3K-Akt, FoxO, HIF-1, and p53. PASS prediction indicated that catechin, quercetin, and myricetin showed the highest probabilities for antioxidant activity, inhibition of lipid peroxidation and NADPH oxidase, and melanin synthesis inhibition, while ADMET predicted good solubility and high gastrointestinal absorption for most of the identified metabolites. Fungal interactions altered the phenolic composition of basidiomycete mycelia and influenced their biological activities, indicating that co-cultivation may be a useful strategy for modulating the production of bioactive metabolites. Full article

Natural inland saline–alkaline wetlands offer opportunities for evaluating microbial responses to long-term salinity stress. This study examined surface soils from non-saline, moderately saline, and hypersaline sites in the Luyang Lake wetland, measuring comprehensive edaphic variables (including SAR, ESP, carbonate/bicarbonate chemistry, moisture, DOC, and inorganic N) alongside bacterial and fungal communities via 16S rRNA and ITS sequencing. A coupled salinity–ion and nutrient gradient was identified, with hypersaline soils characterized by high Na⁺, Cl⁻, SAR, and ESP alongside depleted organic carbon and nitrogen. Bacterial α-diversity exhibited a significant unimodal response along the salinity gradient (quadratic regression: p < 0.001), peaking at moderate salinity. Fungal Shannon diversity declined with increasing salinity, but fungal Chao1 richness showed a U-shaped response, highlighting domain-specific and metric-dependent patterns along the gradient. Community assembly analyses revealed contrasting dynamics: deterministic processes were more prevalent in bacterial assembly in hypersaline soils, while fungal assembly remained predominantly stochastic. Co-occurrence networks showed sparser topological structure in high-salinity soils. These patterns are consistent with domain-specific microbial variation along the gradient to coupled edaphic stressors in inland saline–alkaline wetlands. Full article

Oxidative stress poses significant challenges for fungi inhabiting extreme environments. Elevated salinity frequently induces the excessive production of reactive oxygen species (ROS), which can damage cellular components and impair growth. In response, fungi—common inhabitants of extreme environments—activate coordinated adaptive mechanisms, including antioxidant defense systems and other stress-related pathways. In the present study, a newly isolated strain, Trichoderma afroharzianum B2.2, obtained from the poorly studied saline habitat of Atanasovsko Lake (Bulgaria), was investigated. The cellular response of this moderately halotolerant strain to increased salinity was characterized. Biomarkers of oxidative stress were evaluated, and the involvement of key enzymes from glycolysis and the pentose phosphate pathway in the strain’s adaptation to elevated salinity was examined. Understanding adaptations to salt environments is crucial not only for elucidating fungal survival mechanisms under extreme conditions but also for their potential applications in biotechnology, ecology, and food safety, particularly in the context of increasing ecosystem salinization and climate change. Full article

Eutherian mammals possess 11 metavirus-derived genes, collectively known as the sushi-ichi retrotransposon homologue (SIRH)/Retrotransposon Gag-like (RTL) genes. Several members of this group function in microglia, where SIRH3/RTL6, SIRH8/RTL5, and SIRH10/RTL9 mediate innate immune responses against bacterial-, viral-, and fungal-derived pathogen-associated molecular patterns, respectively, whereas SIRH11/RTL4 responds to noradrenaline and is thought to contribute to stress-responsive brain functions. In addition, the retroviral Env-derived gene ERVPb1 has been implicated in yolk sac-derived resident macrophage lineages, suggesting that both Gag- and Env-derived domesticated genes contributed to the evolution of mammalian neuroimmune systems. Microglia are now recognized as central regulators of neural circuit formation, brain homeostasis, and neuroimmune function, and their dysfunction has been implicated in a wide range of neurological and psychiatric disorders. Here, we review current knowledge of virus-derived genes that have shaped the functional evolution of microglia. We also revisit the concept of “Placenta-driven evolution,” which proposes that the relatively hypomethylated developmental environment of extraembryonic tissues, including the placenta and yolk sac, facilitates the retention and functional co-option of virus-derived sequences, thereby accelerating eutherian evolution. Finally, by integrating recent advances in virus-derived genes and retroelement biology, we discuss how this evolutionary framework may extend beyond extraembryonic tissues to other hypomethylated developmental environments, including the germline and preimplantation embryos. Full article

Apple Valsa canker disease, caused by Valsa mali, is one of the most destructive diseases of apple trees in China and seriously threatens the sustainable development of the apple industry. VmSom1 acts as a core transcription factor in the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) signaling pathway and regulates vegetative growth, development and pathogenicity of this phytopathogen. Transcriptome analysis was performed using the VmSom1 deletion mutant and the wild-type strain sdau11-175, and a significantly differentially expressed transcription factor, VmGAL4, was identified. In this study, the single-gene deletion mutant ΔVmGAL4 and the double-gene deletion mutant ΔVmSom1/VmGAL4 were constructed via homologous recombination, aiming to preliminarily explore the interaction between these two genes. Sequence analysis revealed that the VmGAL4 protein contains a conserved fungal_TF_MHR domain spanning amino acids 164 to 614. Phylogenetic analysis indicated that VmGAL4 shares the closest phylogenetic relationship with homologs from Cytospora schulzeri and Cytospora chrysosperma. Phenotypic assays demonstrated that the VmGAL4 deletion mutant exhibited markedly reduced mycelial growth rate and fewer pycnidia production. Additionally, the mutant displayed enhanced sensitivity to cell wall inhibitors and osmotic stress agents, along with significantly increased capacity to utilize various carbon and nitrogen sources and decreased pathogenicity compared with the wild-type strain. Compared with the single deletion mutant ΔVmSom1, the double mutant ΔVmSom1/VmGAL4 partially rescued the growth defects and also alleviated the reduction in pathogenicity to a certain extent. Nevertheless, conidial production remained severely inhibited in the double mutant. Collectively, VmGAL4 is involved in the regulation of vegetative growth, asexual development, cell wall integrity, osmotic stress response, carbon and nitrogen source utilization, and pathogenicity in V. mali. Full article

Plant-pathogenic bacteria threaten crop productivity and quality, yet chemical options remain limited compared with those for fungal and oomycete diseases. Current management relies mainly on copper bactericides, limited antibiotics, induced-resistance agents, biocontrol and resistant cultivars. However, copper and streptomycin resistance, efflux-mediated multidrug tolerance and rapid pathogen adaptation have weakened these strategies. Target-oriented research provides a framework for exploring agricultural antibacterials, anti-virulence agents, anti-colonization strategies, resistance sensitizers and host-resistance interventions, but many of these approaches remain conceptual, model-system, greenhouse or medical-bacteriology-derived rather than proven field solutions. This review classifies bacterial control targets into two interconnected groups: growth-essential targets, including peptidoglycan biosynthesis, membrane/envelope systems, nucleic-acid processes, protein synthesis, metabolism, nutrient transport and cell division; and anti-virulence/anti-adaptation targets, including secretion systems, quorum sensing, biofilms, motility, adhesion, cell-wall-degrading enzymes, tolerance systems, oxidative-stress responses and host susceptibility factors. Using “Candidatus Liberibacter asiaticus” (CLas) as a case study, genome annotation and infection-stage transcript-abundance data prioritized Sec-dependent secretion, outer-membrane/surface proteins, Bam assembly, nutrient transporters, Clp proteostasis, redox adaptation and core cellular processes as candidate target classes. Envelope-associated, secretion/anti-virulence, nutrient-acquisition and stress-sensitization modules may represent potential directions for downstream validation, but CLas candidates remain hypothesis-generating priorities requiring validation for essentiality, conservation, druggability, delivery feasibility, crop safety and field performance. Full article

The DUF538 gene family, harboring unknown functional proteins, has been reported to take active roles in plant development and response to adversities, while few studies of genome-wide identification and functional verification have been performed in cotton. Hence, two ancestral diploid species, G. arboretum and G. raimondii, and two cultivated tetraploid ones, G. hirsutum and G. barbadense, were chosen in this study to investigate the cotton DUF538 gene family, resulting in 37, 37, 70, and 70 members identified, respectively. A phylogenetic tree was constructed on these cotton DUF538 genes, together with 22 A. thaliana ones, which were divided into seven groups unevenly distributed across nearly all chromosomes. High-degree conservatism, while rich in diversity, was separately observed in gene structure and conserved motif analyses between the same groups and different groups, and a great number of gene-replication events were detected from intraspecific and interspecific collinearity analyses, implying this was the driving force for DUF538 family expansion. Multiple cis-acting elements relevant to adversity-stress responses were found in the promoter region, which were consistent with the transcriptome expression analyses in response to low-temperature and drought stress and Verticillium wilt infection. Coincidentally, GhDUF538-7 showed the core position in the protein–protein interaction network and was identified in the overlapping region of the interval of four reported VW resistance-related QTLs. The gene function of GhDUF538-7 was verified via gene cloning, relative expression-pattern detection, and virus-induced gene silencing (VIGS) experiment. The TRV:DUF538-7 plants showed more serious VW symptoms, significantly severe disease indices, relatively higher fungal biomass, and increased brown vascular bundles compared with TRV:00 plants. Significantly lower expression levels of marker genes PR4 and MYC2 in jasmonate signaling pathways indicated GhDUF538-7 as a potentially positive regulatory factor in plant defense via hormone signal transduction. This study not only broadened the research perspective of evolution and functional differentiation of the cotton DUF538 gene family, but it also revealed the cooperative relationship between DUF538-7 and the JA pathway for further molecular mechanisms of cotton resistance to VW infection. Full article

Chronic rhinosinusitis (CRS) is an inflammatory disease of the sinonasal mucosa whose pathogenesis is characterized by complex interactions of immunological and environmental factors. The maintenance of normal sinonasal function requires a balance of sinus ostial patency, mucociliary clearance, and mucus secretion, and disruption of this balance can lead to CRS. Although many studies have examined the pathophysiology of CRS, the role of reactive oxygen species (ROS) remains incompletely understood. In this review, we analyzed 22 studies of CRS that examined the effects of ROS on epithelial barrier function, local immune responses, and tissue remodeling. The results from in vitro studies, animal models, and human tissue analyses suggest that ROS are not merely by-products of inflammation, but appear to function as key mediators in the pathophysiology of CRS, particularly in the formation and persistence of the CRS phenotype with nasal polyps (CRSwNP). In particular, CRSwNP is characterized by increased activity of enzymes in the dual oxidase (DUOX) and NADPH oxidase (NOX) families, mitochondrial dysfunction, and decreased activity of superoxide dismutase (SOD) and peroxiredoxin 2 (PRDX2). At the molecular level, these alterations increase the generation of ROS and impair antioxidant defense. At the cellular level, these alterations disrupt the epithelial barrier, activate inflammasomes, increase pyroptosis, and induce the formation of neutrophilic and eosinophilic extracellular traps. These changes culminate in the epithelial–mesenchymal transition (EMT), with the formation of nasal polyps and tissue remodeling. Increased oxidative stress can also occur in CRS without nasal polyps (CRSsNP), but this phenotype appears to have relatively preserved antioxidant defense systems, which may partly explain the more limited structural remodeling. External stimuli, such as fungal proteases, bacterial toxins, and certain antibiotics, can also increase the production of ROS and may contribute to disease chronicity. Taken together, the level and pathophysiological roles of ROS differ in the two primary phenotypes of CRS. Further mechanistic studies are needed to clarify the specific alterations of redox pathways in these two phenotypes and to develop novel therapeutic strategies that target ROS. Full article

Fungal communities associated with the phyllosphere can influence plant health, stress responses, and disease dynamics in managed crop systems. However, limited information is available on fungal microbiome structure across phyllosphere compartments of Eucalyptus cinerea cultivated for cut foliage production. In this study, fungal communities (including epiphytic and endophytic fungi) associated with leaf, stem, and bark tissues of intensively managed E. cinerea grown in Ireland were characterised using ITS amplicon sequencing. Samples were collected from five trees, with tissues pooled by compartment to generate 15 biological samples. Following quality control and denoising, 405 fungal amplicon sequence variants (ASVs) were retained for analysis. Observed richness, Shannon and Simpson indices, and Faith’s phylogenetic diversity differed among compartments, with bark exhibiting higher values than leaf and stem tissues (p < 0.05). PERMANOVA analysis indicated that both compartment (R² = 0.239, p = 0.002) and tree identity (R² = 0.451, p = 0.002) significantly influenced fungal community composition. Bark communities were dominated by Diaporthe (52.9%), Peniophora (12.8%), and Talaromyces (10.4%), whereas leaf and stem communities were characterised primarily by Vishniacozyma and Sporobolomyces. Differential abundance analysis identified 26 and 23 differentially abundant ASVs between bark and leaf, and bark and stem tissues, respectively, whereas no significant differences were detected between leaf and stem communities. Weighted UniFrac analyses further revealed separation of bark-associated communities from photosynthetic tissues. These findings demonstrate compartment-associated variation in fungal community structure within the phyllosphere of managed E. cinerea and highlight the importance of considering both host-level and tissue-level effects in plant microbiome studies. This study provides a baseline assessment of fungal assemblages associated with commercially managed Eucalyptus under Irish growing conditions and supports future investigations into the functional significance of these microbial communities for plant health and resilience. Full article

Drought-induced water stress is a major constraint on crop productivity, especially under climate change conditions. In previous work, we isolated a fungal endophyte, Leptobacillium sp. Sl27, from Solanum lycopersicum and found that its growth-promoting effects were dependent on the tomato genotype. In this study, we investigated whether Sl27 modulates early plant responses to water stress in the following two tomato genotypes with differing sensitivities to drought: ADX2 and MO-10. Seeds were inoculated with the endophyte, and 4-week-old seedlings were subjected to water stress by withholding watering for 12 days under controlled growth chamber conditions. We assessed plant performance by measuring physiological parameters (including photosynthetic rate, transpiration, and stomatal aperture) and overall stress response by leaf phenotypic traits. Under severe stress conditions, Sl27-inoculated plants, particularly in the more sensitive genotype MO-10, showed reduced early damage and partially maintained physiological activity during initial stages of stress. However, under prolonged stress, all plants reached similarly high levels of damage, indicating that the effect was transient and did not confer sustained drought tolerance. To explore plant performance under more moderate and agronomically relevant conditions, a second independent experiment was conducted in MO-10 using a controlled water deficit (40% field capacity) and plantlet-stage inoculation. In this experimental context, Sl27 primarily promoted plant growth, increasing shoot and root biomass, with a non-significant trend toward improved performance under stress. Overall, these results indicate that Sl27 does not confer classical drought tolerance but instead improves plant performance and modulates early responses to water deficit in a genotype-dependent manner, with stronger effects observed in the more sensitive genotype MO-10. Full article