Search Results (607)

MicroRNAs (miRNAs) are central regulators of gene expression and play pivotal roles in plant antiviral defense. In Cucurbitaceae, a globally important crop family including cucumber, melon, and watermelon, viral pathogens such as CGMMV, CMV, and ZYMV represent major constraints on productivity. However, the regulatory complexity of miRNA-mediated antiviral responses in these species remains incompletely understood. This review provides an integrated overview of recent advances in miRNA-guided antiviral immunity in Cucurbitaceae, highlighting the dynamic reprogramming of small RNA pathways upon viral infection. Conserved miRNA families act as key regulatory hubs, controlling development, hormone signaling, and defense responses, while viral suppressors interfere with RNA silencing machinery, reshaping host regulatory networks. Emerging evidence further reveals multilayered interactions between miRNAs and other non-coding RNAs, including lncRNAs and circRNAs, indicating complex cross-talk that fine-tunes antiviral responses in a species- and virus-specific manner. Importantly, miRNAs exhibit a dual role by contributing both to antiviral defense and to symptom development. Advances in artificial miRNAs and RNA-based technologies underscore their potential for engineering durable virus resistance. Overall, miRNA-centered regulatory networks represent a promising target for next-generation crop protection strategies in Cucurbitaceae. 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

The 9th National Congress of the Italian Society for Virology (SIV-ISV), entitled “One Virology—One Health”, took place in Turin at the Centro Congressi Lingotto from 22 to 24 June 2025. The meeting highlighted recent multidisciplinary and translational developments in virology, with a strong focus on the integration of the One Health perspective. Major themes included viral emergence and surveillance, genomic sequencing and bioinformatics, virus–host interactions, viral immunology and vaccines, structural and physical virology, environmental and food virology, zoonoses and animal infections, diagnostics and antiviral therapy, virus-based biotechnology and plant virology. The Congress aimed to: (i) bring together clinicians, basic researchers, veterinarians, environmental microbiologists, bioinformaticians, public-health professionals and industry to share methodologies and best practices; (ii) provide an interactive scientific environment promoting discussion and collaboration between senior investigators and trainees through plenaries, joint society sessions, invited talks, oral communications selected from abstracts, poster sessions, and mentoring panels; and (iii) identify priorities and inspire new research directions at the interface of human, animal and environmental health. More than 400 participants from national and international institutions attended the meeting, featuring distinguished plenary speakers, joint sessions with global networks, and numerous presentations of original unpublished data. This report summarizes the meeting’s scientific highlights, cross-disciplinary discussions, and proposed actions to strengthen One Health surveillance, computational infrastructures, and translational applications of viral biology. Full article

The mosquito-associated virome may modulate host biology and influence vector competence, highlighting the importance of understanding its composition. Here, a metagenomic analysis was conducted to characterize the virome of the sea-rock pool mosquito Aedes mariae across sexes and developmental stages, together with water from its sea-rock pool breeding site in San Felice Circeo (Italy). A total of 51 viral taxa were identified, including viruses associated with bacteria and archaea (39%), plants, algae, fungi, and protists (35%), vertebrates (8%), and invertebrates (18%), including insect-specific viruses such as Mesoniviridae, Baculoviridae, Nudiviridae, Iridoviridae and Totiviridae. Twenty-five percent of the taxa were shared across samples, suggesting acquisition from breeding-site water and persistence across stages during development. Interestingly, the need for host genome filtering highlights the potential sequence similarity between viral and mosquito genomes, which may reflect the presence of endogenous viral elements or historical virus–host interactions. These findings represent the first characterization of the virome of Aedes mariae and highlight the role of aquatic breeding sites in shaping mosquito virome. Finally, we argue the importance of adequate sequencing depth and host genome filtering to capture the diversity of the mosquito virome. Full article

The southern rice black-streaked dwarf virus (SRBSDV) is transmitted by the white-backed planthopper (WBPH), Sogatella furcifera, but not by the co-occurring brown planthopper (BPH), Nilaparvata lugens. Understanding the influence of virus infection of host plants on the performance of close-related vector and non-vector species is an interesting topic for exploring virus–plant–herbivore interactions. This study investigates how SRBSDV infection of rice plants affects the performance of WBPH and BPH and the plant defense responses. Differential performance of the two planthopper species was observed. On infected plants, WBPH displayed prolonged male nymphal development, increased adult longevity, enhanced feeding, and reduced fecundity, which contrasts the reduced nymph survival and fecundity in BPH. SRBSDV infection triggered an increase in salicylic acid (SA) levels and upregulated the expression of SA-related genes (ICS1 and NPR1) in response to WBPH feeding, but not to BPH feeding. These results show that SRBSDV reshapes the host plant defense in a manner that alters key vector traits favoring virus transmission while impairing the fitness of a competing non-vector, which advances current understanding of virus–plant–herbivore interaction. Full article

Potyvirus rapae (turnip mosaic virus, TuMV) is widely used as a model system in plant–virus interaction studies. The TuMV RNA genome encodes 11 proteins, some of which remain poorly characterized, while the functions of others are well defined. Studying individual proteins in isolation may not recapitulate native expression levels, subcellular localization, and interaction with host factors during virus replication and movement. An alternative approach is to tag individual viral proteins in the context of an infectious clone. Epitope tags may alter protein functions and affect viral replication, movement, or a combination of essential steps, thus leading to changes in pathogenicity. Because they have central roles in viral infection, here we measured the effect of individually tagging the helper component proteinase (HC-Pro) and nuclear inclusion protein b (NIb) with a 6His-3xFLAG tag. Epitope tags were placed at the N-terminus of HC-Pro and the N- and C-termini of NIb within a TuMV infectious clone carrying coding sequences for the green fluorescent protein (TuMV-GFP). Constructs carrying a tagged HC-Pro displayed pathogenicity similar to that observed for TuMV-GFP in Nicotiana benthamiana and Arabidopsis thaliana plants. In contrast, infectivity of NIb-tagged clones became temperature sensitive and, even at the permissive temperature, showed reduced pathogenicity compared to TuMV-GFP. Providing a silencing suppressor in trans did not restore infection efficiency, suggesting reduced viral fitness due to structural or functional disruption caused by the epitope tags. Structural models generated using AlphaFold2 showed no effect of the tag on HC-Pro. In contrast, structural models illustrated tag interference with the NIb catalytic site. AlphaFold2 was further used to predict the structural impact of several tags on NIb and to predict the effect of a 6HIS-3xFlag tag on all other TuMV proteins. This study provides a broadly applicable framework for selecting suitable epitope tags to mark viral proteins and maintain function in the context of virus infection. Full article

Tomato yellow leaf curl virus (TYLCV) is a major plant pathogen that spreads worldwide through persistent circulative transmission by Bemisia tabaci. During transmission, TYLCV crosses several physiological barriers in the insect vector, evading immune defenses and altering host metabolic pathways to facilitate viral accumulation. Polyamines, essential for maintaining nucleic acid stability and promoting cellular processes, are known to play a critical role in viral accumulation. However, their role in TYLCV accumulation within B. tabaci is not well understood. Here, we demonstrate that TYLCV infection leads to significant alterations in polyamine levels in B. tabaci, with polyamine availability positively affecting viral DNA accumulation. Polyamine availability leads to higher viral loads and suppresses the expression of immune and MAPK signaling genes. These findings provide new insights into virus–vector and metabolic interactions underlying viral persistence in insect vectors. Full article

Verticillium wilt (VW), caused by the soil-borne fungus Verticillium dahliae, is a major disease that markedly compromises both the yield and fiber quality of cotton. In this study, we explored the function and underlying mechanism of the cotton expansin gene GhEXLB2 in response to VW infection. Expression profiling revealed that members of the GhEXL family exhibit distinct patterns across tissues and under various biotic and abiotic stresses. Notably, GhEXLB2, which encodes an extracellular protein, showed the strongest induction following V. dahliae challenge. Ectopic expression of GhEXLB2 in Arabidopsis thaliana promoted root elongation and root hair formation, and was associated with improved resistance to the pathogen. In contrast, silencing GhEXLB2 in cotton via virus-induced gene silencing (VIGS) led to pronounced vascular browning, increased pathogen recovery, and a lower level of disease resistance. In addition, RNA-seq profiling of GhEXLB2-silenced (VIGS) cotton plants revealed that most differentially expressed genes were enriched in pathways related to phytohormone signaling and plant–pathogen interactions, with salicylic acid (SA) signaling and WRKY transcription factors emerging as central regulatory components. Analysis of the GhEXLB2 promoter further identified multiple cis-acting elements associated with stress and hormone responsiveness. When integrated with protein–protein interaction (PPI) prediction data, these results suggest that GhEXLB2 may be modulated by a network of transcription factors and signaling pathways. Collectively, the evidence supports a positive association between GhEXLB2 and VW resistance. This study provides a framework for understanding expansin functions in cotton defense against VW. Full article

Plant viruses need to use many host factors to establish infection. During the viral cycle, intracellular transport is fundamental to reach the plasmodesmata to enable cell-to-cell transport. Cucumovirus CMV (cucumber mosaic virus, CMV) can infect plants from most economically important crops. To identify additional host proteins involved in CMV movement in melon, we used the MP as a bait to screen a Yeast two-hybrid cDNA library from CMV-infected plants and identified a Niemann-Pick C1 (NPC1) protein as a novel MP interactor. NPC1 is a transmembrane protein involved in cholesterol transport in animal cells, but also in the infection by several viruses of different families. The identified clone from the melon NPC1 gene spans from exons 25 to 28 and includes two introns. Notably, deletion of the two introns and exon 28 does not impair the interaction capacity of the remaining peptide. The identified CmNPC1 gene maps to chromosome 11. In addition, the melon genome encodes a second copy of NPC1 in chromosome 7 (CmNPC1-C7), highly similar. Functional assays revealed that the interaction domain of CmNPC1-C7 also interacts with CMV MP, suggesting that both genes could have a role in CMV infection. This study represents the first report linking NPC1 to the infection process of a plant virus, expanding our understanding of plant–virus interactions. Full article

Background/Objectives: Epigenetic regulation plays a fundamental role in controlling the spatiotemporal expression of genes in plants under stressful environmental conditions. While LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) is known to be involved in histone modification, its function in regulating the biosynthesis of specialized metabolites, particularly monoterpenoid indole alkaloids (MIAs) in Catharanthus roseus, remains elusive. Methods: CrLHP1 was identified by mining the C. roseus proteome and characterized through sequence alignment, phylogenetic analysis, and conserved domain assessment. Virus-induced gene silencing (VIGS) was employed to suppress CrLHP1 expression, after which the transcript levels of jasmonic acid (JA)-responsive genes and key MIA biosynthetic genes, as well as the accumulation of vindoline and catharanthine, were analyzed. Furthermore, deep learning-based protein structure prediction (AlphaFold3) and yeast two-hybrid (Y2H) assays were conducted to explore protein-protein interactions. Results: CrLHP1 was confirmed as the ortholog of Arabidopsis thaliana LHP1 (AtLHP1). Exposure to 75 μM MeJA upregulated MIA upstream pathway genes while downregulating CrLHP1 transcription. Silencing CrLHP1 significantly upregulated JA-responsive and MIA biosynthetic genes, leading to enhanced catharanthine accumulation. Additionally, the structural prediction and Y2H assays revealed a physical interaction between CrLHP1 and CrJAZ1. Conclusions: These findings suggest that CrLHP1 negatively regulates MIA biosynthesis, potentially by modulating JA signal transduction through interaction with CrJAZ1. This study provides new insights into the possible epigenetic mechanisms governing alkaloid production in C. roseus. Full article

Geranyl diphosphate synthase (GPPS) is a key enzyme in the plant isoprenoid metabolic pathway and regulates the biosynthesis of volatile monoterpenes. It plays an important role in the biosynthesis of floral volatile terpenoids (FVTs) and inter-cultivar variation in snapdragon. Despite its importance in floral scent formation, the GPPS/GGPPS gene family in snapdragon (Antirrhinum majus L.) has not been systematically characterized. In this study, nine GPPS/GGPPS family members were identified at genome-wide level. These include six AmGPPS and three AmGGPPS genes. Phylogenetic analysis grouped them into distinct subfamilies. We further analyzed their chromosomal locations, gene structures, conserved protein motifs, and promoter cis-acting elements. These results revealed both conservation and functional divergence within the gene family. To explore their functional roles, we compared gene expression profiles at the full flowering stage. This comparison was performed between strongly scented cultivar (Am3) and the weakly scented cultivar (Am5). Among all candidates, AmGPPS6 showed the most significant differential expression. Further, functional validation was conducted using transient overexpression and virus-induced gene silencing (VIGS). Overexpression of AmGPPS6 significantly increased terpenoid production. Total floral volatile terpenoids (FVTs) increased by 1.4 fold. Both monoterpene and sesquiterpene emissions were enhanced. In contrast, silencing of AmGPPS6 markedly reduced the emission of key monoterpenes such as ocimene and its isomers. Sequence analysis showed that AmGPPS6 shares 67.04% identity with canonical GPPS small subunit (GPPS.SSU). However, it lacks the conserved catalytic DDx2-D motif. This suggests that AmGGPPS2 is not catalytically active. Instead, it likely functions through heterodimer with AmGGPPS2. This interaction is supported by coordinated transcriptional expression patterns. Additionally, natural sequence polymorphisms were identified in GPPS.SSU. These variations, rather than those in GPPS.LSU, appear to drive differences in monoterpense emission between cultivars. In conclusion, AmGPPS6 in a key regulator of floral scent biosynthesis in snapdragon. This study provides new insights into functional roles of GPPS/GGPPS genes. It also offers valuable gene targets for the molecular breeding of aromatic traits in ornamental plants. Full article

RNA viruses exhibit high mutation rates, necessitating antivirals targeting conserved infection mechanisms. In this study, viral hemorrhagic septicemia virus (VHSV), a non-human pathogenic negative-sense RNA virus, was used as a surrogate model to enable high-throughput antiviral screening under reduced biosafety conditions. A recombinant VHSV expressing enhanced green fluorescent protein was used to screen 17,265 compounds, 2000 plant extracts, and 100 marine extracts. Among the candidates, the leaf extract of Phellodendron amurense Rupr. (PL extract) exhibited antiviral activity with low cytotoxicity (selectivity index ≈ 10). The extract reduced viral infectivity in a dose-dependent manner and showed cross-activity against snakehead rhabdovirus. Mechanistic analyses indicated that the PL extract acts primarily at early stages of infection. Virucidal assays demonstrated direct, time-dependent inactivation of viral particles, while pre-treatment reduced host cell susceptibility. Time-of-addition experiments confirmed that antiviral activity was restricted to early infection, suggesting interference with viral attachment or entry rather than intracellular replication. Fractionation revealed that activity was associated with the non-polar n-hexane fraction, implicating lipophilic compounds that may disrupt viral envelope integrity or membrane interactions. These findings suggest that P. amurense leaf extract is a promising candidate for broad-spectrum antivirals targeting conserved entry processes in enveloped RNA viruses. Full article

Soil salinity limits ginger productivity, but the underlying molecular mechanisms remain largely unclear. The 14-3-3 proteins are conserved regulators in stress signaling. Here, we genome-wide characterized the 14-3-3 family in Zingiber officinale and examined the possible involvement of Zo14-3-3-03 in salt response. A total of 21 Zo14-3-3 genes were identified and classified into four groups with uneven chromosomal distribution. Among them, Zo14-3-3-03 was strongly salt-responsive: transcript levels increased 9.91- to 33.82-fold during 1–7 days of treatment and reached 62.47-fold in leaves at day 14. NaCl treatment elevated GUS expression driven by the Zo14-3-3-03 promoter. Virus-induced gene silencing (VIGS) of Zo14-3-3-03 resulted in silenced plants exhibiting higher malondialdehyde (up to 73.6%), lower antioxidant enzyme activities (SOD, POD, CAT, and APX: 18.9–31.9% reduction), reduced osmolytes (proline, soluble protein, sugars, and ascorbic acid: 23.2–36.2% reduction), excessive reactive oxygen species, and decreased relative water content. Several antioxidant-related genes were significantly downregulated. Protein interaction assays suggested a possible interaction with ZoSOS2, and the expression of SOS2 pathway genes was altered in silenced plants, indicating a potential link to calcium signaling and ion homeostasis. Taken together, these results suggest that Zo14-3-3-03 participates in ginger salt stress response possibly through redox balance, osmotic adjustment, and calcium-mediated pathways which would provide a basis for understanding 14-3-3-mediated stress responses and nominates Zo14-3-3-03 as a candidate requiring deeper validation for salt tolerance improvement in ginger. Nevertheless, due to limited functional validation, its role as a positive regulator and breeding target remains preliminary. Further genetic and mechanistic studies are needed to confirm causality and assess field-level applicability. Full article

Background: A major challenge in antiviral development is the identification of novel virus–host interactions while ensuring therapeutic efficacy and safety. These challenges have renewed interest in phytochemicals derived from medicinal plants as alternative antiviral agents. Objectives: In this study, we investigated the antioxidant, antiviral, and immunomodulatory properties of a Mediterranean Urtica dioica extract (UdE) against SARS-CoV-2 using chemical, biochemical, and in vitro approaches. Methods: The physicochemical properties of UdE were characterized using microtiter assays and HPLC analysis. Cytocompatibility was evaluated in HEK293T, Vero E6, Caco-2, and Calu-3 cell lines while antioxidant activity was assessed using both chemical and cell-based assays. Antiviral activity was evaluated by assessing inhibition of SARS-CoV-2 receptor binding domain (RBD)–ACE2 interaction using ELISA, inhibition of SARS-CoV-2 main protease (Mpro) activity via FRET assay and inhibition of viral entry using SARS-CoV-2 S1 pseudovirus neutralization assay. Results: UdE (100 µg/mL) inhibited RBD–ACE2 binding by 94% and suppressed Mpro activity by 74%, while reducing moderate but significant inhibition of pseudovirus entry (33.6%) at 300 µg/mL dose level in ACE2 expressing HEK293T cells. Immunomodulatory analysis revealed significant suppression of IL-1β and IL-6 production, accompanied by increased TNF-α and IL-8 levels. Conclusions: Collectively, these findings highlight that UdE exhibits multi-target in vitro antioxidant, antiviral, and immunomodulatory activity against SARS-CoV-2; therefore, UdE represents a promising bioactive extract for the management of SARS-CoV-2 infection. Full article

In recent years, nanotechnology has made remarkable progress in the fight against infectious diseases. However, the development of safe and effective antiviral drugs remains a challenge, as viruses rely on host cells for replication. Plant-derived, environmentally friendly nanoparticles have gained significant attention due to their low toxicity, which enables them to target viruses without damaging host cells. In this study, we describe the synthesis of silver nanoparticles (AgNPs) using Arctostaphylos uva-ursi leaf extract and explore their potential antiviral activity. The uva-ursi AgNPs were initially characterized using nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM). We then optimized two different gellan gum/alginate film formulations (1.6:0.4 and 1.2:0.8) as delivery matrices for the AgNPs and assessed Ag⁺ skin permeation using a Franz diffusion cell system. The antiviral potential of the uva-ursi AgNPs—both alone and incorporated into the films—was tested against herpes simplex virus type 1 (HSV-1). Our findings indicate that uva-ursi AgNPs may directly interact with the viral envelope, disrupting the lipid membrane and/or interfering with viral surface proteins. Overall, green-synthesized uva-ursi AgNPs may represent a natural, cost-effective, and safe alternative strategy for managing herpetic infections. Full article