Search Results (9,623)

The seedling production stage of lettuce (Lactuca sativa L.) is crucial for crop success, as it determines the initial quality of the plants. The use of seeds with rapid and uniform germination is essential to ensure proper seedling establishment. Among sustainable alternatives for water management, irrigation with ozonated water stands out due to its disinfectant potential and its ability to stimulate plant physiology. This study evaluated the effects of irrigation with ozonated water on the production and development of lettuce seedlings. The experiment was conducted in a completely randomized design (CRD) arranged in a 2 × 2 factorial scheme, with four replications. Two lettuce cultivars were tested: one with smooth leaves and another with crisp leaves. The variables analyzed included germination parameters (final percentage, germination index and mean germination rate, uniformity, and time to reach 10, 50, and 90% germination), as well as initial growth parameters (total height, shoot and root height, and dry matter content). Analyses were performed on 20 seedlings per cultivar. Irrigation with ozonated water promoted significant growth (p < 0.05) of the shoot and root growth, with increases of 16.90 and 4.99% for the smooth-leaf cultivar, and 24.27 and 9.26% for the crisp-leaf cultivar, compared to the control. Ozone application did not alter the microbiological, physical, or chemical parameters of the water. These growth-promoting effects are likely associated with increased oxygenation of the root zone, enhanced oxidation of organic matter in the substrate, and improved nutrient availability promoted by ozone-derived radicals, which may also optimise root respiration and reduce pathogenic pressure. The applied concentration of 5 mg L⁻¹ O₃ over a 25-day seedling production cycle proved effective and did not cause phytotoxic effects. Irrigation with ozonated water is an efficient and environmentally safe alternative for producing vigorous lettuce seedlings. Full article

Rice (Oryza sativa L.) production is constantly threatened by devastating diseases such as rice blast, bacterial blight, and brown planthopper infestation. The AP2-type transcription factor OsHTR (also known as SMOS1/SHB/RAL1/NGR5/GR5) has been previously implicated in hormonal signaling networks and nitrogen use efficiency; however, its role in disease resistance remains largely unexplored. In this study, we functionally characterized OsHTR in disease resistance using knockout (KO) and overexpression (OE) transgenic lines in the ZH11 background. Transcriptome analysis revealed that differentially expressed genes in the htr mutant were significantly enriched in plant–pathogen interaction pathways, with multiple NBS-LRR and NB-ARC resistance-related genes upregulated. Real-time PCR validation confirmed the upregulation of 15 candidate resistance genes in the htr mutant. Comprehensive resistance evaluations suggested that HTR-KO lines exhibited enhanced resistance to rice blast and bacterial blight compared to wild-type ZH11 and HTR-OE lines, which displayed moderate susceptibility. In contrast, all lines remained highly susceptible to brown planthopper, indicating a disease-specific regulatory function of OsHTR. Furthermore, targeted knockout of individual upregulated resistance-related genes (LOC_Os10g04090, LOC_Os12g29690, LOC_Os02g11980, and LOC_Os11g11770) and OsHTR-interacting gene LOC_Os06g03710 confirmed their distinct contributions to blast and bacterial blight resistance but did not establish them as direct targets of OsHTR. Collectively, our results indicate that OsHTR functions as a negative regulator of disease resistance in rice, likely acting through transcriptional repression of defense-related genes, although direct binding remains to be demonstrated. This study uncovers a novel regulatory module connecting AP2-type transcription factors to disease resistance and provides valuable genetic resources for molecular breeding of broad-spectrum-resistant rice cultivars. Full article

Soil acidification is a widespread consequence of intensive agriculture and represents a major abiotic stress affecting plant performance, nutrient availability, and ecosystem functioning. Long-term tea (Camellia sinensis) plantations provide model systems of chronic acidification, where sustained low pH imposes strong environmental filtering on soil microbial communities. Although microbial responses to acidification have been extensively studied, research has focused predominantly on bacteria and fungi, leaving other key functional groups, particularly protists, largely overlooked. Here, we synthesize current knowledge on microbial communities in acidified soils and highlight trophic interactions, especially protist-mediated regulation, as a potentially critical but underexplored dimension linking abiotic stress to plant–soil processes. We propose that soil acidification may not only filter microbial community composition but also reshape trophic interactions. Based on evidence from other soil systems, protist-mediated trophic interactions could influence nutrient cycling, pathogen suppression, and ultimately plant responses under stress conditions. Integrating environmental filtering with trophic perspectives provides a conceptual framework for understanding microbiome dynamics in acidified soils. However, direct evidence linking protist-mediated trophic regulation to ecosystem functioning and plant performance in tea plantation soils remains limited and requires experimental validation. We further suggest that these systems provide unique opportunities to investigate how abiotic constraints and biotic interactions jointly shape plant performance. Addressing this gap is essential for advancing predictive understanding of plant–microbiome interactions under ongoing environmental change. Full article

The Arabidopsis thaliana Heat Shock Protein-Related (AtHSPR) gene participates in plant growth and abiotic stress tolerance, while its role in biotic stress resistance remains unclear. Here, we report that the athspr mutant is sensitive to Pseudomonas syringae pv. tomato (Pst) DC3000, whereas over-expression of AtHSPR enhances the defense of Arabidopsis against the pathogen. AtHSPR expression was induced by treatment with Pst DC3000, flg22, or salicylic acid (SA). Transcriptome analysis showed that mutation of AtHSPR changed the expression patterns of genes associated with defense response, oxidation–reduction, and SA responses, as well as transcription factors. The biochemical evidence revealed that AtHSPR interacted with Thimet Oligopeptidase 1 (TOP1), which modulated the SA-mediated immune response. Co-expression of AtHSPR and TOP1 showed that the TOP1 protein, normally located in the chloroplasts, gathered around the nucleus in response to a pathogen. After pathogen treatment, dynamic tubular projections (stromules) were present, extending from the chloroplasts toward the nucleus, and TOP1 was observed in the nucleus, together with AtHSPR. The top1athspr double mutant had lower SA levels and was more sensitive to pathogens than the top1 and athspr single mutants. Taken together, our results demonstrated that the interaction between AtHSPR and TOP1 plays a positive role in SA-mediated plant resistance against Pst DC3000. Full article

Salmonella remains one of the most critical zoonotic pathogens in the poultry sector, linked to animal disease, foodborne illness, and the global crisis of antimicrobial resistance (AMR). Poultry acts as a major reservoir, enabling Salmonella transmission from hatchery to retail products through horizontal, vertical, and environmental routes. Despite the use of biosecurity, vaccination, antibiotics, and chemical decontamination, effective and sustainable control across the poultry value chain remains difficult, particularly in the face of rising multidrug-resistant strains and growing consumer concerns over chemical residues. Bacteriophages (phages), viruses that selectively infect and lyse bacteria, have emerged as a promising biological alternative for Salmonella control. Although many studies have reported the effectiveness of phages against bacterial species, including Salmonella, in the poultry industry, reports on their full potential to combat antimicrobial-resistant Salmonella across the entire poultry value chain remain limited. Therefore, this review synthesizes current evidence on the application of phages throughout the poultry value chain, including on-farm interventions, processing plant decontamination, and food packaging and storage. Findings from the reviewed articles indicate over a 90% reduction in Salmonella spp. in poultry farms and post-harvest meat, along with lower mortality in phage-treated groups compared to untreated groups; however, these outcomes depend on several factors (e.g., phage strains, concentrations, application methods, and environmental conditions). Laboratory, pilot, and field studies consistently demonstrate that phage preparations, especially when formulated as cocktails or combined with complementary interventions, can achieve substantial reductions in Salmonella, including antibiotic-resistant serovars, in live birds, eggs, poultry environments, and meat products. Unlike antibiotics and chemical sanitizers, phages act with high specificity, preserving beneficial microbiota and maintaining the sensory and nutritional quality of poultry products. Their safety has been supported by toxicological and genomic assessments, and several phage-based products have obtained regulatory approval, including Generally Recognized as Safe (GRAS) status for food applications in the United States. By integrating efficacy, safety, regulatory, and practical deployment data, this review highlights bacteriophages as a scientifically validated and One Health–aligned tool capable of reducing Salmonella transmission from farm to fork across the poultry value chain, thereby laying the foundation for their future adoption in the poultry industry. Phage-based interventions offer a sustainable pathway to enhance food safety, limit antimicrobial resistance (AMR) dissemination, and strengthen consumer confidence in poultry products. However, the major limitation is the emergence of phage-resistant bacterial strains, as well as the potential involvement of some phages in the transfer of resistance and virulence genes, which could raise public concern. Nevertheless, the use of phage cocktails and whole-genome sequencing, involving tools such as ResFinder and virulence finder, can facilitate the selection of safe phages for application. Full article

Grapevine downy mildew, caused by the oomycete pathogen Plasmopara viticola (P. viticola), is one of the most devastating diseases threatening the global grape industry. The pathogen invades host plants through stomata, triggering a series of highly coordinated physiological disorders and biochemical defense events. This review systematically summarizes the dynamic changes in morphological structures (stomatal characteristics), physiological functions (photosynthesis, membrane system integrity, and carbon metabolism), and multi-level biochemical defense systems (reactive oxygen species (ROS) scavenging enzyme system, phenylpropanoid metabolic pathway, pathogenesis-related proteins, and phenolic compounds) in grapevines following infection. It focuses on analyzing the differences in the timing, intensity, and metabolic reprogramming of defense responses between resistant and susceptible cultivars, pointing out that the essence of disease resistance lies in early pathogen recognition and rapid defense induction. The conflicting conclusions regarding indicators such as soluble sugars, peroxidase (POD), and superoxide dismutase (SOD) are discussed from the perspectives of experimental systems, cultivar genetic backgrounds, and pathogen physiological race differences. Furthermore, the known physiological and biochemical alterations are linked to upstream signaling pathways, including salicylic acid and jasmonic acid (SA/JA), calcium signaling, and mitogen-activated protein kinase (MAPK) cascades. Recent advances in revealing resistance mechanisms in the omics era are also introduced. Finally, future research directions are proposed, including constructing multi-indicator dynamic evaluation models, verifying key gene functions using gene editing, exploring the potential of epigenetic regulation, and developing integrated control strategies combined with microbiome research. This review aims to provide theoretical support for grapevine downy mildew resistance breeding and sustainable disease management. Full article

The increasing consumption of fresh organic produce has given rise to concerns regarding the microbiological safety of minimally processed foods. Organic cultivation may be associated with increased exposure to environmental microorganisms due to soil-based inputs and reduced chemical interventions, including both beneficial taxa and potential foodborne pathogens. Fresh produce is known to harbour complex microbial ecosystems, which are shaped by farming practices, plant physiology, handling, packaging and storage, particularly in raw-consumed products such as leafy greens and strawberries. In this study, bacterial (16S rRNA) and eukaryotic (18S rRNA) communities were characterized by amplicon sequencing. In parallel, an amoeba-associated bacterial microbiome was analyzed and DVC-FISH was used to assess the viability and metabolic activity of pathogenic bacteria internalized within free-living amoebae (FLA). No significant differences in alpha or beta diversity were observed between organic and conventional products, suggesting microbiome convergence at the retail stage driven by post-harvest handling and processing. Potentially pathogenic genera, including Pseudomonas, Stenotrophomonas, and Acinetobacter (bacterial), as well as Tilletiopsis, Candida, and Naegleria (eukaryotic), were identified in both organic and non-organic microbiomes. The viability of FLA-internalized Pseudomonas spp. was confirmed by DVC-FISH, demonstrating that FLA act as reservoirs, enhancing pathogen persistence in fresh produce. This integrated assessment of organic and conventional fruits and vegetables at the retail stage highlights the importance of post-harvest handling and retail conditions in shaping microbiological safety. The integration of microbiome profiling with targeted viability analyses demonstrates that downstream stages are critical control points for food safety and consumer exposure, beyond the influence of the production system alone. Full article

Pathogenesis-related (PR) proteins are crucial for plant defense against pathogen infection. However, the specific role of thaumatin-like proteins (TLPs), which comprise the PR-5 family, in plant immune responses has not been thoroughly investigated. Filipendula ulmaria is a medicinal plant with valuable pharmacological properties, including antimicrobial, anti-inflammatory, gastroprotective, immunomodulatory, and anticancer activities. The structure of the TLP family and its role in the immune system of meadowsweet have not been studied so far. The goal of this study was to analyze in detail the TLP gene family in meadowsweet and explore its response to fungal infection. In the meadowsweet genome, we identified 27 putative TLP genes, examined their structure and location on chromosomes, analyzed cis-regulatory elements in the promoter regions, predicted the structure and physicochemical characteristics of the encoded proteins, and performed a phylogenetic analysis. We also studied the differential expression of TLP genes under Bipolaris sorokiniana infection. Of six differentially expressed genes, three genes were up-regulated 48 h post-infection, suggesting their involvement in defense response to the fungus. The results obtained shed light on the role of the TLP gene family in the immune system of F. ulmaria and form the foundation for the creation of disease-resistant crops in agriculture and the development of bio-based antimicrobials in medicine. Full article

Plants must continuously balance the trade-offs between growth and defense, a constraint that is exacerbated by biotic and abiotic stresses, particularly when they occur together. Ethylene (ET) serves as a central, integrative regulatory node controlling this by linking developmental programs to stress-responsive signaling networks. Advances at the molecular and systems levels have revealed that ET mediates the redistribution of metabolic resources via coordinated regulation of its synthesis, perception, and downstream signaling. The ETR (Ethylene Receptor)-CTR1 (Constitutive Triple Response 1)-EIN2 (Ethylene Insensitive 2)-EIN3(Ethylene Insensitive 3) signaling module lies at the core of this network, integrating multiple hormonal pathways. Through dynamic crosstalk with jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), auxin (AUX), and gibberellins (GA), ET enables the fine-tuned coordination of growth inhibition, immune activation, and stress acclimation in response to environmental fluctuations. Processes such as induced systemic resistance, programmed cell death, and architectural plasticity further reinforce this regulatory framework, with ethylene-responsive transcription factors, including ERFs (ethylene responsive factor gene family) and WRKYs, acting as critical convergence points. Emerging insights into ACC (1-aminocyclopropane-1-carboxylic acid)-dependent signaling, chromatin remodeling, and tissue-specific regulation expand the functional scope of ET beyond traditional hormone paradigms. At the same time, the ability of pathogens to manipulate ET signaling underscores its dual role in both promoting immunity and facilitating susceptibility. By integrating molecular, physiological, and ecological perspectives, this review highlights ET as a central coordinator of plant stress resilience and growth optimization, providing a unifying framework for understanding how plants adapt to complex and dynamic environments. Full article

Extracellular vesicles (EVs) are key mediators of intercellular communication across biological kingdoms, with central roles in immune regulation and disease processes. Despite shared structural features, EVs derived from bacteria, plants, and mammalian cells differ substantially in their biogenesis, molecular composition, and immunological functions. EV formation pathways generate vesicles with distinct cargo profiles, including pathogen-associated molecular patterns (PAMPs) in bacterial EVs, regulatory small RNAs in plant-derived vesicles, and cytokines, microRNAs, and antigen-presenting complexes in mammalian EVs. Differences in cargo result in divergent immune outcomes. Bacterial EVs predominantly activate innate immunity via pattern recognition receptors such as Toll-like receptors, whereas plant-derived EVs exhibit low immunogenicity and mediate cross-kingdom RNA interference. In contrast, mammalian EVs primarily regulate immune responses by modulating antigen presentation and cytokine signaling. These findings support a framework in which EV origin determines immunological function and therapeutic applicability. This perspective highlights the importance of selecting appropriate EV sources for vaccine development, regenerative medicine, and targeted delivery strategies, while addressing current challenges related to heterogeneity, standardization, and safety. Full article

Celosia cristata and Alternanthera philoxeroides both belong to the family Amaranthaceae. Of the two species, C. cristata serves as a medicinal herb as well as an ornamental plant, whereas A. philoxeroides is a notorious invasive weed. In 2024, leaf spot symptoms were observed on C. cristata and A. philoxeroides in Jingzhou City, Hubei Province, China. Based on morphological characteristics and multilocus phylogenetic analysis using sequences of ITS, GAPDH, TEF1, RPB2, and Alt a 1, the pathogen isolated from both hosts was identified as the same species, Alternaria alternantherae. However, differences in morphology were observed between the strains from different hosts. Pathogenicity assays confirmed that this species can cross-infect both host plants. In addition, sensitivities of the pathogen to four fungicides (prochloraz, tebuconazole, azoxystrobin, and carbendazim) were tested in vitro and in vivo. The results revealed that the pathogen was highly sensitive to fungicides prochloraz and tebuconazole. These findings provide valuable insights into the management of leaf spot disease on C. cristata and the development of integrated control strategies for A. philoxeroides. Full article

Background/Objectives: Numerous natural compounds have been reported to exhibit anti-virulence properties against pathogenic bacteria. Particularly, plants constitute a rich source of anti-quorum-sensing (QS) and anti-biofilm compounds with highly diverse chemical structures. Notably, several studies reported that plant-derived pentacyclic triterpenoids exert anti-biofilm activity against Pseudomonas aeruginosa without affecting bacterial viability, suggesting that this class of naturally occurring chemical compounds may represent a source of potent and clinically relevant anti-biofilm agents. Methods: To further investigate this hypothesis, we evaluated several commercially available pentacyclic triterpenoid acids of the oleanane, ursane and lupane types for their potential impact on QS mechanisms and biofilm formation in the P. aeruginosa PAO1 model strain. Results: Oleanane-type (oleanolic acid and maslinic acid), ursane-type (ursolic acid and corosolic acid) and lupane-type (betulinic acid) triterpenoids inhibited the expression of the QS-regulated lasB and rhlA genes as well as biofilm formation, without affecting bacterial growth. Among tested compounds, oleanolic and ursolic acids, at 400 µM, exhibited the strongest anti-biofilm activities, with 45% and 40% inhibition, respectively. Fluorescence microscopy revealed a marked disorganization of biofilm architectures, with bacterial communities failing to establish compact cell-to-cell attachment and confluent microcolonies. Further analyses indicated that these triterpenoid acids did not affect the expression of QS-regulator genes (lasR/I and rhlR/I), suggesting that their impact on lasB and rhlA expression and biofilm formation is independent of the las and rhl systems. Conclusions: These findings suggest that oleanane and ursane triterpenoid acids represent promising chemical backbones for the development of strategies aimed at inhibiting P. aeruginosa biofilm formation. Full article

Orchid plants, due to their high aesthetic qualities of large inflorescences, long flowering period, and ease of care, have high commercial potential; however, when grown industrially in factories, they are susceptible to infectious diseases. In this study, we isolated from Phalaenopsis spp. plants epiphytic, rhizospheric, and endophytic bacteria associated with soft rot symptoms. Twenty-nine isolates exhibiting pectolytic activity were identified as strains of the genera Bacillus, Klebsiella, Microbacterium, Paenibacillus, Paracidovorax, Pseudomonas, and Psychrobacillus based on 16S rRNA analysis. These isolates were tested for their ability to produce cellulase, amylase, sucrase, proteinase, and lipase; to form biofilms; and to exhibit motility (swimming and swarming). Potato microplants under in vitro conditions were used as a model object for initial screening of the strains’ potential phytotoxicity. Most strains were shown to inhibit plant growth, particularly root development. Injection of suspensions of these strains into orchid leaves caused symptoms of soft rot. Thus, we isolated Gram-positive bacteria for the first time from orchid tissues with soft rot symptoms and demonstrated an association of these strains with plant tissue maceration in potato and orchids. Gram-positive bacteria with pectolytic activity are not typical pathogens of orchid soft rot and may require changes in approaches to the monitoring of phytopathogens for this group of plants. Full article

Background: Essential oils (EOs) are promising natural antimicrobials against food-borne pathogens, yet their efficacy depends on complex chemical profiles that vary by species and origin. The evaluation of underexplored aromatic plants from the Peruvian Amazon may reveal novel bioactive agents. Methods: We chemically characterized six EOs from Aloysia citrodora, Arracacia xanthorrhiza (two cultivars), Baccharis genistelloides, Piper acutifolium, and Piper lanceifolium using GC-MS and assessed their antibacterial activity against Escherichia coli (ATCC 25922), Salmonella enterica (ATCC 14028), Enterococcus faecalis (ATCC 29212), and Staphylococcus aureus (ATCC 49476). Results: EOs of Aloysia citrodora and Arracacia xanthorrhiza cv. Yellow exhibited the strongest inhibition, effective against both Gram-positive and Gram-negative bacteria, potentially associated with higher relative abundances of oxygenated monoterpenes and aliphatic aldehydes. Dose–response analysis supported their superior antibacterial potency, with the lowest LD₅₀ values observed for these oils. Oils rich in sesquiterpenes showed lower activity. Conclusions: These findings underscore the importance of EO chemical composition for antibacterial potency and suggest that select Amazonian EOs have potential as natural preservatives for food safety applications. Full article

Armillaria is a genus of macrofungi with high ecological, biological, medicinal, and edible value. As facultative plant pathogens and nutritional symbionts, Armillaria species support the growth of valuable medicinal plants including Gastrodia elata and Polyporus umbellatus. They also exhibit unique traits such as exceptional longevity, widespread clonal expansion, rhizomorph formation, and bioluminescence, making them a valuable model for studying fungal ecology, symbiosis, specialized metabolism, and applied research. This review summarizes recent progress in Armillaria research, covering biological characteristics, nutritional components, bioactive constituents, species identification, genomic resources, and biosynthetic pathways. We discuss advances in artificial cultivation and the regulatory roles of exogenous phytohormones in mycelial and rhizomorph development. The nutritional value of fruiting bodies is highlighted, with a focus on key pharmacologically active metabolites such as protoilludane-type sesquiterpenes and polysaccharides. We also review multilocus phylogenetic analysis, comparative genomics, and the biosynthetic gene clusters of melleolides and bioluminescence, which have improved understanding of Armillaria evolution and functional differentiation. Full article