Hellebores (Helleborus spp.) are herbaceous perennial plants that are widely grown for their winter and early spring flowers (Eastwell et al. 2009; Liefting et al. 2010). In 2022, hellebores (Helleborus orientalis) exhibiting severe virus-like symptoms characterised by dark brown to black streaking on sepals, bracts, and stems, as well as irregularly shaped dark lesions on foliar tissues (Figure 1), were collected from a private garden located in the Blue Mountains region of New South Wales (NSW), Australia. It was noted that approximately 10% of the hellebore population in the garden exhibited symptoms. The collected symptomatic tissues were subjected to diagnostic screening at the NSW Department of Primary Industries and Regional Development Plant Health Diagnostic Service laboratory. The symptoms observed appeared consistent with those of hellebore black death, which is associated with Helleborus net necrosis virus (HeNNV, Carlavirus necroretis), a member of the Carlavirus genus (Eastwell et al. 2009; Liefting et al., 2010; Rubino 2024). A composite from multiple samples consisting of symptomatic sepal, bract, and leaf tissues was subjected to transmission electron microscopy following a negative-stain preparation. The electron microscopy analysis revealed filamentous virus-like particles measuring 650-700 nm length, with slightly flexuous and curved properties (Figure 2), which were consistent with those belonging to the Carlavirus genus. In addition, total RNA was extracted from a composite of multiple samples comprised of symptomatic sepal, bract, and leaf tissues using the Bioline ISOLATE II RNA Plant Kit (Meridian Bioscience), following the manufacturer’s instructions. The total RNA integrity was verified via High Sensitivity RNA ScreenTape Analysis (Agilent Technologies) and used to prepare an RNA-Seq library followed by sequencing as described in Maina et al. (2021), using the MiSeq cycle 2 x 251 v3 kit (Illumina). The obtained raw reads were trimmed and de novo assembled as described in Maina et al. (2021). Assembled contigs were subjected to BLASTn analysis, and a single contig of 8,534 nucleotides (nt) sharing 99.3% sequence identity with a HeNNV genome (GenBank accession NC_012038.1) was obtained. The contig of interest was represented by 2.6% of the total reads (79,136 reads out of 3,006,106 total reads), giving an average genome coverage of 1336x. The genome sequence was deposited in GenBank under accession PV165322 (isolate M22-15435). To confirm the presence of HeNNV in the original hellebore sample, specific primers targeting the HeNNV coat protein gene were designed (Sol_F-CCACTCAGCTCTCCAATTGTTA and Sol_R-CCTTCCTGTGCCTGGTTAAA) and used to conduct RT-PCR (at 57°C annealing temperature) using the original RNA sample followed by Sanger sequencing, yielding an amplicon of the expected size (604 bp) that shared 100% identity with the HTS contig. To our knowledge, this is the first detection and report of HeNNV infecting hellebores in Australia. The introduction of HeNNV to Australia may have inadvertently occurred through the importation of infected hellebore propagules. This HeNNV detection reinforces the importance of stringent biosecurity screening of imported plant propagules entering Australia. In addition, the identification of this virus contributes to the knowledge of hellebore black death aetiology. Furthermore, this report will enhance HeNNV awareness, assisting hellebore growers to adopt management strategies aimed at reducing the potential spread and impact of HeNNV disease in Australia.

The endomembrane system of the intestinal pathogen Giardia lamblia lacks a separate Golgi compartment. Without this sorting compartment, how cargo sorting to various subcellular destinations occurs within Giardia remains an open question. While the distribution of various Golgi-associated SNAREs and Rabs has been documented in this parasite, the TRAPP (TRAnsport Protein Particle) complex, a guanine nucleotide exchange factor for Golgi-associated Rabs, remained uncharacterized. Herein, we report that Giardia expresses a minimal set of TRAPP complex components, GlBet3, GlBet5, GlTrs23, and GlTrs31. Some of these components can interact with GlRab1a, GlRab11, and the COPII coat protein, GlSec23. Coupled with the colocalization and coimmunoprecipitation of GlBet3 and GlBet5, we propose the existence of a functional TRAPP complex in Giardia with an architecture that is different from that of yeast. While some interactions within this complex may be analogous to those in yeast, we find evidence of some unique interactions as well. The TRAPP genes are upregulated during encystation, and two components are associated with encystation-specific vesicles. Besides the endomembrane system, the presence of GlBet3 and GlBet5 at the plasma membrane, membrane wrapping ventral disc periphery, and the median body indicates that the TRAPP complex may support unique features and functions of Giardia.

A novel virus belonging to the genus Victorivirus was identified in the plant-pathogenic fungus Colletotrichum gloeosporioides. Its genome is a double-stranded RNA molecule of 5217 bp containing two open reading frames (ORFs). The 5'-proximal ORF (ORF1) encodes a coat protein (CP) consisting of 734 amino acids (aa), whereas the 3'-proximal ORF (ORF2) encodes an RNA-dependent RNA polymerase (RdRp) of 875 aa. The two ORFs overlap at the tetranucleotide sequence AUGA, facilitating a coupled termination-initiation mechanism, which is characteristic of members of the genus Victorivirus. The amino acid sequences of RdRp and CP were found to be most similar (42% and 34% identical, respectively) to those of the Ustilaginoidea virens RNA virus 1. Phylogenetic analysis based on RdRp and CP sequences further supported the placement of this virus within the genus Victorivirus. The genome of this victorivirus, for which we propose the name "Colletotrichum gloeosporioides victorivirus 1" (CgVV1), is 5.2 kb in length and was one of several dsRNA segments identified in the fungal isolate, indicating coinfection with other mycoviruses. To the best of our knowledge, this is the first report of a victorivirus infecting C. gloeosporioides.

In Japan, only one satsuma dwarf virus (SDV) isolate has been fully sequenced to date. This study provides complete genome sequences of six SDV isolates for which only partial sequences had been determined and three for which no sequence data were available. Among all known isolates, nucleotide sequence identity was found to range from 67.9 to 98.6% for RNA1 and from 67.9 to 98.8% for RNA2. The amino acid sequence identity in the coat protein (CP) ranged from 76.9 to 99.2%. Phylogenetic analysis revealed that five of the nine newly sequenced isolates clustered with the citrus mosaic virus (CiMV) strain, two with the SDV strain, and one each with the navel orange infectious mottling virus (NIMV) and hyuganatsu virus (HV) strains.

The family Geminiviridae comprises 15 genera and over 500 species of diverse plant-infecting viruses. Previous studies on this virus’s diversity primarily focused on the members’ selection without considering the entire genomic divergence. This study presents comprehensive comparative genomic analyses and a global distribution map using 17,718 complete genomes and 28,185 geminivirus-associated metadata records. Intergeneric pairwise identity among monopartite and Begomovirus DNA-A is ≥ 40%, while interspecies identity among Begomovirus DNA-B is ≥ 41%, corresponding to genetic variations of ≤60% and ≤59%, respectively. Begomovirus and Mastrevirus are the only genera detected across all continents, with Asia exhibiting the highest genus diversity (11 genera). However, in Africa, geminiviruses from six genera are more broadly distributed across individual countries. To our knowledge, this is the first geographical map constructed using all genera from the Geminiviridae family. Phylogenetic reconstructions of complete genomes, coat proteins, and replication-associated proteins (Rep) underscored distinct clustering patterns consistent with genus-level classification but revealed exceptions, including misclassified viral species and potential new taxa. Notably, French bean severe leaf curl virus with accession KC699544 was reclassified from Capulavirus to Begomovirus with the proposed name Corchorus yellow vein mosaic virus. Additionally, two unclassified begomovirus-like viruses, named “begomovirus spathoglottis 1” and “2,” are proposed for reclassification within Maldovirus under the tentative names “maldovirus spathoglottis 1” and “2.” The Begomovirus Rep showed phylogenetic affinity with Rep from Maldovirus, Curtovirus, Turncurtovirus, and Topocuvirus, supporting potential evolutionary relationships among these genera. Recombination analyses confirmed high-frequency interspecies and intergeneric recombination events, predominantly involving Begomovirus, underscoring its pivotal role in geminivirus evolution. Furthermore, we hypothesized specific vector transmission: Opunvirus, Welwivirus, and Topilevirus are transmitted via treehopper species, whereas Citlodavirus and Eragrovirus are transmitted via leafhopper species. Accurate identification and classification of plant viruses and their transmission vectors are essential for developing effective surveillance and management strategies to safeguard global agriculture.

The family Geminiviridae comprises 15 genera and over 500 species of diverse plant-infecting viruses. Previous studies on this virus's diversity primarily focused on the members' selection without considering the entire genomic divergence. This study presents comprehensive comparative genomic analyses and a global distribution map using 17,718 complete genomes and 28,185 geminivirus-associated metadata records. Intergeneric pairwise identity among monopartite and Begomovirus DNA-A is ≥ 40%, while interspecies identity among Begomovirus DNA-B is ≥ 41%, corresponding to genetic variations of ≤60% and ≤59%, respectively. Begomovirus and Mastrevirus are the only genera detected across all continents, with Asia exhibiting the highest genus diversity (11 genera). However, in Africa, geminiviruses from six genera are more broadly distributed across individual countries. To our knowledge, this is the first geographical map constructed using all genera from the Geminiviridae family. Phylogenetic reconstructions of complete genomes, coat proteins, and replication-associated proteins (Rep) underscored distinct clustering patterns consistent with genus-level classification but revealed exceptions, including misclassified viral species and potential new taxa. Notably, French bean severe leaf curl virus with accession KC699544 was reclassified from Capulavirus to Begomovirus with the proposed name Corchorus yellow vein mosaic virus. Additionally, two unclassified begomovirus-like viruses, named "begomovirus spathoglottis 1" and "2," are proposed for reclassification within Maldovirus under the tentative names "maldovirus spathoglottis 1" and "2." The Begomovirus Rep showed phylogenetic affinity with Rep from Maldovirus, Curtovirus, Turncurtovirus, and Topocuvirus, supporting potential evolutionary relationships among these genera. Recombination analyses confirmed high-frequency interspecies and intergeneric recombination events, predominantly involving Begomovirus, underscoring its pivotal role in geminivirus evolution. Furthermore, we hypothesized specific vector transmission: Opunvirus, Welwivirus, and Topilevirus are transmitted via treehopper species, whereas Citlodavirus and Eragrovirus are transmitted via leafhopper species. Accurate identification and classification of plant viruses and their transmission vectors are essential for developing effective surveillance and management strategies to safeguard global agriculture.

Transcription-associated torsional stress presents a continuous threat to genome integrity that needs to be tightly controlled. Here we present a method for the visualization of genome maintenance events at sites of active transcription, which builds on a previously developed reporter system that allows for the detection of nascent, MS2-repeat containing transcripts with a YFP-tagged MS2 coat protein. We describe steps to monitor Topoisomerase 1 engagement as a result of transcription-associated topological stress in both S phase and non-S phase cells, and detail procedures to visualize TOP1 cleavage complex formation and concomitant DNA repair factor engagement. We expect this system to provide a powerful means to study effectors of the transcription-associated topological stress response.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10577-025-09789-9.

The life cycle of flowering plants starts when a zygote is formed following a double fertilization event. To achieve fertilization, sperm cells are delivered to the female gametes within the embryo sac by the tip-growing pollen tube. The fast-growing pollen tube is characterized and regulated by abundant transport vesicles responsible for both exocytosis and endocytosis in the tip region. Visualization of these tip-vesicles has been challenging owing to their small size, high dynamics, and complexity. In this study, we illustrated the three-dimensional (3D) ultrastructure of tip-vesicles in growing pollen tubes of lily, tobacco, and Arabidopsis. Five major types of tip-vesicles, including secretory vesicles (SVs), electron-dense vesicles (DVs), clathrin-coated vesicles (CCVs), mini vesicles (MVs), and extracellular vesicles (EVs), can be distinguished using room-temperature electron tomography (RT-ET) based on their ultrastructural features. We also demonstrated the extensive distribution of tubular endoplasmic reticulum (ER) structures at the apex of growing pollen tubes and vesicles budding from the tip-localized ER. Cryo-ET further revealed the tip-localized tubular ER with budding coat protein complex II (COPII) vesicles. Our study thus offered a structural basis for a deeper comprehension of vesicular trafficking in the tip growth of the pollen tube, aiding future research on vesicle-mediated membrane trafficking in polarized cell growth.

Turnip mosaic virus (TuMV) is one of the emerging viruses that causes serious yield losses of brassica vegetables, including Indonesia. Broccoli (Brassica oleracea var. italica) is a potential horticultural commodity in Indonesia because of its many benefits. The objective of this study was to detect TuMV-infecting broccoli using reverse transcription polymerase chain reaction (RT-PCR) technique. Field survey has been conducted to determine disease symptoms in broccoli field Boyolali, Central Java. This study was conducted through several phases, which are: leaves sample collection on the field, virus RNA isolation, RT-PCR, and TuMV detection using coat protein (CP) specific primer. The result of field observed broccoli plant with several symptom of TuMV infection, such as: mosaic symptom leaf, blister leaf, vein banding, vein clearing, and yellowing of leaf spot. The detection of TuMV by RT-PCR showed that broccoli with those symptoms observed is positively infected by TuMV. Specific DNA band was amplified from infected plant on 800 bp. This study is report of naturally infection of TuMV on broccoli with those symptoms at Boyolali, Central Java, Indonesia.

Society’sdrinking water needs are increasingly met by reusingmunicipal wastewater, necessitating high virus Log10 ReductionValues (LRVs). Concurrently, electrified processes are gaining prominencefor water/wastewater treatment. Herein, we report that electrocoagulationwith a low-carbon steel anode and graphite cathode at pH 6.5 and 5.5and iron dose of 20 mg/L reduced the MS2 coliphage below detectionlimits (LRVs ≳6.7) in just 11.5 min. Matrix AssistedLaser Desorption Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF-MS)of electrocoagulated viruses revealed single, double, and triple oxygenadducts and a negative mass shift peak in its coat protein withoutcleavage/scission. Density functional theory calculations coupledwith computational spatial interaction mapping evidenced the formationof the quintet ferryl ion-cysteine 46 cluster. Hence, inactivationappears to have been accompanied by nonproteolytic capsid damagesinduced by reactive oxygen species (ROS). Evidence also pointed topossible ROS interactions with arginine 49 and tryptophan 32 residues.The ratio of viralprotein secondary structuresquantified by deconvoluting the amide I region of infrared spectrastrongly and negatively correlated with inactivation, carbonyl groupcontent, and MALDI-TOF-MS-derived protein alterations. Hence, ironelectrocoagulation achieved high virus LRVs by removal (through enmeshment)and inactivation (via specific ROS interactions with coat proteinresidues).

The ability of virus shells to encapsulate a wide range of functional cargoes, especially multiple cargoes─siRNAs, enzymes, and chromophores─has made them an essential tool in biotechnology for advancing drug delivery applications and developing innovative new materials. Since therapeutic cargo may be formulated in different physical states (size, surface charge, etc.) we have investigated the spontaneous encapsulation of multiple, charged, small nanoparticles which repel when free in solution, inside a spherical cage formed of brome mosaic virus (BMV) coat proteins. Unlike the cases of coassembly of virus-like particles (VLPs) from multiple oligonucleotides and single nanoparticle cargo, the structure of virus-like particles thus obtained is consistent with that of the native icosahedral BMV capsid. Working with small metal nanoparticles as cargo allowed the pathway of assembly to be followed by electron and liquid atomic force microscopy and cryoelectron tomography. Based on the structural identification of nanoparticle─BMV protein intermediates, we have found that multiple cargo encapsulation occurs in stages through a specific "assembly line" pathway that is different from the previously described in vitro assembly mechanisms of virus-like particles (VLP). We propose a model that explains the experimental findings, some of which will be important for delivery applications, for instance, the pronounced nanoparticle size selectivity in competition experiments where different nanoparticle sizes are present.

Mango (Mangifera indica), a globally significant fruit crop, is susceptible to diverse pathogens that threaten its productivity. High-throughput sequencing-based virome profiling and Sanger sequencing of symptomatic (mosaic, upward leaf curling with undulated margin in the young leaves) mango samples revealed the presence of a novel olivavirus (mangifera virus 1, MaV-1), and a benyvirus (mangifera indica latent virus, MiLV). Comparative genomic and phylogenetic analyses confirmed the taxonomic placement of MaV-1 within the proposed genus Olivavirus, based on conserved domains and sequence divergence in the RdRp, HSP70h, and coat protein genes. This study represents the first report of MiLV in India and a novel MaV-1 species infecting mango worldwide. Current study enhances understanding of mango viral spectrum and highlights the need for viral surveillance to address the potential threats to mango cultivation.

The production of recombinant proteins for pharmaceutical, industrial, and agricultural applications remains a significant challenge in developing nations like Nigeria, where infrastructure limitations and cost constraints hinder access to conventional production systems. Plant virus-based expression systems, particularly those derived from tobacco mosaic virus (TMV), offer a promising alternative due to their high yield potential, rapid production cycles, and cost-effectiveness. This review comprehensively examines the development and optimization of TMV-based vectors for enhanced protein production, with specific attention to applications relevant to Nigeria's agricultural and public health needs. We detail the molecular mechanisms underlying TMV's efficiency as a gene expression vector, including the role of viral movement proteins, untranslated regions (UTRs), and coat protein modifications in boosting foreign protein accumulation. Recent advancements in vector design-such as TMV-Gate vectors for high-throughput applications and deconstructed viral systems for industrial-scale production-are discussed alongside optimization strategies involving host plant selection, agroinfiltration techniques, and co-expression of silencing suppressors. We present a case study conceptualizing the production of a malaria vaccine antigen in Nigerian tobacco species, addressing both technical feasibility and economic considerations. Despite challenges related to protein size limitations, host defense responses, and regulatory frameworks, TMV-based systems hold transformative potential for Nigeria's biomanufacturing capacity. This review concludes with future perspectives on adapting this technology to local contexts, emphasizing research investment, infrastructure development, and capacity building as essential components for harnessing plant molecular farming to address pressing national needs.

Marine actinomycetes are a promising source for developing new antiviral agents for plant diseases, as they produce a wide variety of bioactive compounds. To date, antiviral activity of marine actinomycetes against plant viruses are rare. The present study proceeded to identify and characterize promising antiviral actinomycetes from Red Sea in Hurghada, Egypt, control Cucumber Mosaic Virus (CMV) and, profile the individual chemical components of bioactive crude extracts. Biological and molecular characterization was performed to identify CMV isolate using RT-PCR and coat protein (CP) gene nucleotide sequences analysis. In squash plants, antiviral, CMV optical density, biochemical responses, and resistance genes expression of Streptomyces extracts (SE1 and SE2) were performed against CMV by disease incidence, severity (%) assays, ELISA technique, physiological analysis, and real-time quantitative PCR (qPCR). Chemical profiling of the two Streptomyces extracts was investigated using GC–MS analysis. Antiviral activity was performed by curative (C), protective (P), and inactivation (I) techniques under greenhouse conditions. The obtained results of the morphological, biochemical, physiological and molecular level studies of the Streptomycetes isolates ph6 and MARH showed similarity towards the species of Streptomyces and identified as Streptomyces variabilis strain ph6 (OQ283766) and Streptomyces sp. strain MARH (OQ283775). Protective treatments (P: SE1 and P: SE2) resulted in disease suppression of 100%, while curative treatments (C: SE1 and C: SE2) by 87% and 100%, and inactivation treatments (I: SE1 and I: SE2) by approximately 70%, and 80% respectively compared to mock-inoculated plants. The absorbance values of ELISA at 405 nm for P: SE1 and P: SE2 were 0.191 ± 0.02, and 0.187 ± 0.00 respectively compared to CMV-infected plants which recorded 0.854 ± 0.00. Levels of ascorbate peroxidase (APX), catalase (CAT) enzymes, proline content, total photosynthetic pigments, and total phenolic compounds were significantly increased in P: SE1 and P: SE2 treated squash plants compared to CMV-infected plants. Moreover, P: SE1 and P: SE2 increased membrane stabilization and reduced electrolyte leakage. The pathogenesis-related (PR) gene such as PR-b1 was overexpressed by about 3.09-, and 10.37-fold increases and PR-2 by 1.07-, and 1.66-fold increases for P: SE1 and P: SE2 respectively compared to the CMV-infected control group. Chemical profiling of the ethyl acetate extracts of Streptomyces variabilis and Streptomyces sp. MARH authenticated the presence of constituents such as 1,3¬Dinitro¬2-imidazolidinone (42.60%), Nephthoside-1,2’,3’,4’-Tetraacetate (76.18%), Tetraphenylporphyrinato dichlorotitanium(IV) (12.42%) and L-Lysine (17.01%) respectively. Our results showed that Streptomyces variabilis and Streptomyces sp. MARH are promising strains for production of antiviral natural products, increasing the phenolic compounds, activity of the antioxidant enzymes, and induction the expression of pathogenesis-related genes to generate systemic acquired resistance (SAR) in squash plants. They also supported the potential use of their extracts as an environmentally friendly novel bio-virocides to sustainably stop the spread of plant viruses.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-31348-9.

BackgroundOnion yellow dwarf virus (OYDV), a devastating pathogen affecting garlic (Allium sativum), causes significant agricultural losses worldwide. Current management strategies rely on chemical pesticides that pose environmental and toxicity concerns, hence emphasizing the urgent need for eco-friendly alternatives.ResultsThis study aimed to discover plant-derived inhibitors of OYDV by targeting its coat protein through several computational approaches. The CP of OYDV was characterized, and a high-quality 3D model was validated. Through high-throughput molecular docking of 46 plant-based metabolites, four compounds were selected: hypericin, celastrol, sanguinarine, and asiatic acid with superior binding affinities (below − 9 kcal/mol). These four had exceptionally high docking scores, outperforming the commercial antivirals ribavirin and ningnanmycin. These top ligands have been proven to be less hazardous via in silico toxicity profiling, which makes them suitable for the development of biopesticides. DFT analysis and MD simulations validated the stability and structural flexibility of the hypericin and coat protein, respectively.ConclusionThese computational findings suggest hypericin could be a promising lead compound for developing sustainable OYDV management strategies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12870-025-07745-7.

About one-third of the eukaryotic proteome transits the secretory pathway to reach its correct cellular or extracellular destination. At the earliest stage, transport from the endoplasmic reticulum (ER) to the ER-Golgi intermediate compartment (ERGIC) or Golgi apparatus is mediated by coat protein complex II (COPII). COPII coats consist of inner and outer layers formed by Sec23-Sec24 heterodimers and Sec13-Sec31 heterotetramers, respectively, which initially assemble at ER exit sites (ERES) to form transport carriers. Sec23-interacting protein (Sec23IP) links the inner and outer coats through its interactions with both Sec23A and Sec31A, positioning it as a key potential regulator of COPII function. However, the mechanisms controlling Sec23IP activity remain poorly understood. Here, we investigate how physiological stimuli regulate COPII function through the dynamic modification of Sec23IP by O-linked β-N-acetylglucosamine (O-GlcNAc), a reversible, intracellular form of glycosylation. We first validated Sec23IP as a bona fide O-GlcNAcylated protein. Rescue experiments in Sec23IP knockout cells with a nearly unglycosylatable mutant protein demonstrated the essential role of O-GlcNAcylation in the intrinsically disordered domain in protein transport and in recruiting Sec31A to ERES. Moreover, O-GlcNAcylation of Sec23IP increased during protein transport, coinciding with a reduction in its interaction with Sec31A. These results indicate that distinct site-specific O-GlcNAcylation of Sec23IP spatiotemporally modulates its association with Sec31A to fine-tune ERES recruitment and COPII assembly/disassembly. Our work provides new insight into Sec23IP regulation and suggests that O-GlcNAc on other COPII proteins may govern carrier formation, uncoating, and transport.

Chilli veinal mottle virus (ChiVMV), a member of the Potyviridae family, a major threat to solanaceous crops, including tobacco and peppers, in China, where it causes systemic necrosis, leaf mottling, and significant yield losses. Early and accurate detection is essential for effective disease management, yet conventional assays such as RT-PCR and ELISA are constrained by laboratory requirements and skilled personnel. In this study, we developed a colloidal gold-based immunochromatographic strip (ICS) for the rapid, specific, and field-deployable detection of ChiVMV. The viral coat protein (CP) was heterologously expressed in Escherichia coli and used to generate eight hybridoma cell lines, from which two monoclonal antibodies, 22F4 (capture) and 45C4 (detector), were selected. The assembled ICS yielded clear visual results within 5–10 min, with a detection limit corresponding to a 1:1,000 dilution of infected leaf extracts, and exhibited no cross-reactivity with PVY, TVBMV, WYMV, TMV, or CMV. Field testing with 120 tobacco samples demonstrated 95.7% sensitivity and 98.0% specificity, consistent with RT-PCR, and the test strips maintained stability after 12 months of storage at room temperature. This study presents the first rapid ICS for ChiVMV, providing a sensitive, specific, and cost-effective diagnostic tool for on-site disease surveillance and early management in tobacco cultivation.

Tobamoviruses establish viral replication organelles (VROs) on the host endoplasmic reticulum (ER) for their replication, a process demanding substantial different types of lipids. However, how viruses efficiently transfer these lipids from other compartments like chloroplasts remains incompletely understood. Fibrillin (FBN) proteins are primarily localised to chloroplasts and are intimately linked with lipid metabolism and stress responses in chloroplasts. Here, we report that NbLIP1, a light-induced FBN1 family protein in Nicotiana benthamiana, directly interacts with the coat protein (CP) of rehmannia mosaic virus (ReMV) and other related tobamoviruses (TMV, YoMV). Upon viral infection, this interaction leads to the relocalisation of NbLIP1 from chloroplasts to ER-proximal viral replication sites. Functional assays demonstrated that overexpression of NbLIP1 significantly enhanced viral replication, viral protein accumulation, and VRO formation, while silencing NbLIP1 had the opposite effects. These findings unveil a novel viral infection mechanism whereby the viral CP hijacks the host lipid transfer protein NbLIP1 and recruits it to viral replication factories to promote viral replication, potentially by modulating lipid supply or the microenvironment remodelling at the replication sites. This study not only elucidates the role of NbLIP1 as a novel pro-viral host factor but also provides new insights into how viruses exploit host resources across cellular compartments, suggesting NbLIP1 as a potential antiviral target.

Receptor-like kinases (RLKs) reside on the cell surface and recognize apoplastic colonization by plant-infecting microbes to initiate immune responses. Whether RLKs can also recognize intracellular colonization by viruses to activate antiviral defense mechanisms in plants remains unknown. Here, we report the identification and characterization of a trans-Golgi network/early endosome (TGN/EE)-localized RLK that recognizes viral proteins and inhibits infection in rice. OsVIRK1, a cysteine-rich receptor-like kinase, promotes rice resistance to rice stripe virus (RSV), one of the most devastating viruses of rice. OsVIRK1 transcription is induced in RSV-infected rice, and its protein accumulates through autophosphorylation and redox-mediated regulation. OsVIRK1 physically interacts with the RSV coat protein (CP), a known immune elicitor, and nonstructural protein 3 (NS3), an antiviral RNA-silencing suppressor, at the TGN/EE. OsVIRK1 is required for CP-triggered defense gene expression. It phosphorylates NS3, reducing NS3 accumulation in the cytoplasm and thus repressing its activity as an RNA-silencing suppressor. Our findings suggest that OsVIRK1 recognizes viral proteins at the TGN/EE to inhibit infection by activating plant antiviral immunity and dampening viral counterdefense.

Honeybee (Apis mellifera L.) colonies face serious biological threats from bacterial pathogens such as Paenibacillus larvae and Melissococcus plutonius. This study evaluated the inhibitory potential of bacteriocins derived from Apilactobacillus kunkeei strains against multiple virulence factors of these pathogens using in silico methods. Bacteriocins identified by BAGEL4, including Ak-Bac1 (class IIa) and Ak-Bac2 (class III), were subjected to protein–protein docking analyses using ClusPro and HDOCK platforms with three virulence-associated proteins: the amidase enzyme and spore coat protein CotE from P. larvae, and the surface adhesin protein from M. plutonius. The docking results revealed strong binding affinities, particularly between Ak-Bac2 and the P. larvae amidase enzyme, as well as between Ak-Bac1 and the CotE spore protein, suggesting both enzymatic inhibition and spore suppression effects. These findings indicate that A. kunkeei bacteriocins exhibit broad-spectrum antagonistic potential against honeybee pathogens, providing a molecular basis for the development of probiotic-based biocontrol strategies to support honeybee health.