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Arboviruses and symbiotic viruses can be paternally transmitted by male insects to their offspring for long-term viral persistence in nature, but the mechanism remains largely unknown. Here, we identify the sperm-specific serpin protein HongrES1 of leafhopper Recilia dorsalis as a mediator of paternal transmission of the reovirus Rice gall dwarf virus (RGDV) and a previously undescribed symbiotic virus of the Virgaviridae family, Recilia dorsalis filamentous virus (RdFV). We show that HongrES1 mediates the direct binding of virions to leafhopper sperm surfaces and subsequent paternal transmission via interaction with both viral capsid proteins. Direct interaction of viral capsid proteins mediates simultaneously invasion of two viruses into male reproductive organs. Moreover, arbovirus activates HongrES1 expression to suppress the conversion of prophenoloxidase to active phenoloxidase, potentially producing a mild antiviral melanization defense. Paternal virus transmission scarcely affects offspring fitness. These findings provide insights into how different viruses cooperatively hijack insect sperm-specific proteins for paternal transmission without disturbing sperm functions. Arboviruses and symbiotic viruses can be paternally transmitted by male insects to their offspring, but the mechanism remains largely unknown. Here, the authors identify the sperm-specific serpin protein HongrES1 of the leafhopper Recilia dorsalis as a mediator of paternal transmission of the reovirus rice gall dwarf virus and of a previously undescribed symbiotic virus of the Virgaviridae family, Recilia dorsalis filamentous virus, via direct binding of virions to leafhopper sperm surfaces and subsequent paternal transmission via interaction with both viral capsid proteins.

Harpin HrpZ from the plant-pathogen Pseudomonas spp. elicits the hypersensitive response (HR), pathogen defense responses, and enhances growth in plants. To identify regions of HrpZ related to these bioactivities, we constructed 11 mutants of HrpZ sub(PsgS1), a 346-amino-acid harpin protein from P. savastanoi pv. glycinea S1. Results showed that proteins HrpZ sub(74-204) and HrpZ sub(1-194) could not induce macroscopic HR but could elicit microscopic HR in tobacco. The HR elicitation activity of mutant proteins with other C-terminal deletions in HrpZ sub(PsgS1), such as HrpZ sub(1-102), HrpZ sub(195-238), HrpZ sub(241-248), HrpZ sub(254-298), and HrpZ sub(290-313), was reduced. The activity of the remaining mutants, other than HrpZ sub(200-346), which lacks part of the N-terminus, was similar to wild-type. These results indicate that the C-terminus is indispensable for HR elicitation, and that parts of the N-terminus play a regulatory role. Also, mutants HrpZ sub( Delta 89-124) and HrpZ sub( Delta 254-298) enhanced growth in rice more than wild-type HrpZ sub(PsgS1). These mutants were also more effective at inducing resistance to Xanthomonas oryzae pv. oryzae in rice and to Tobacco Mosaic Virus (TMV) in tobacco. qRT-PCR assays showed that HrpZ sub( Delta 89-124) and HrpZ sub( Delta 254-298) induced higher levels of expression in genes related to HR, pathogen defense, and growth. Therefore, the modified proteins HrpZ sub( Delta 89-124) and HrpZ sub( Delta 254-298 may) have potential for development as protein-type biocontrol agents.

Multiple urethane groups in the same rod-like structure template the assembly of aromatic helices to form artificial folded architectures as large as 20 kDa with atomic precision. At the molecular level, translation refers to the production of a new entity according to a template that has a different chemical composition. In this way, chemical information may be translated from one molecule to another. The process is useful to synthesize structures and thus functions that might be difficult to create otherwise, and it reaches exquisite levels of efficiency in biological systems, as illustrated by protein expression from mRNA templates 1 , 2 or by the assembly of the tobacco mosaic virus capsid protein according to the length of its RNA 3 . In synthetic systems, examples of template-directed syntheses are numerous 4 , 5 , 6 , but general and versatile schemes in which a non-natural sequence actually encodes the information necessary to produce a different sequence are few and far from being optimized 7 , 8 , 9 , 10 . Here we show a high-fidelity enzyme-free translation of long rod-like alkylcarbamate oligomers into well-defined sequences of stacked helical aromatic oligoamides. The features present in the rods, which include the number and distance between carbamate functions and stereogenic centres, template the self-assembly of complementary stacks of helices that each have a defined right (P) or left (M) handedness, length and single or double helicity. This process enables the production of very large (>20 kDa) abiotic artificial folded architectures (foldamers 11 ) that may, for example, serve as scaffolds to organize appended functional features at positions in space defined with atomic precision across nanometric distances.

RNA viromes of nine commonly encountered Ochlerotatus mosquito species collected around Finland in 2015 and 2017 were studied using next-generation sequencing. Mosquito homogenates were sequenced from 91 pools comprising 16–60 morphologically identified adult females of Oc. cantans, Oc. caspius, Oc. communis, Oc. diantaeus, Oc. excrucians, Oc. hexodontus, Oc. intrudens, Oc. pullatus and Oc. punctor/punctodes. In total 514 viral Reverse dependent RNA polymerase (RdRp) sequences of 159 virus species were recovered, belonging to 25 families or equivalent rank, as follows: Aliusviridae, Aspiviridae, Botybirnavirus, Chrysoviridae, Chuviridae, Endornaviridae, Flaviviridae, Iflaviridae, Negevirus, Partitiviridae, Permutotetraviridae, Phasmaviridae, Phenuiviridae, Picornaviridae, Qinviridae, Quenyavirus, Rhabdoviridae, Sedoreoviridae, Solemoviridae, Spinareoviridae, Togaviridae, Totiviridae, Virgaviridae, Xinmoviridae and Yueviridae. Of these, 147 are tentatively novel viruses. One sequence of Sindbis virus, which causes Pogosta disease in humans, was detected from Oc. communis from Pohjois-Karjala. This study greatly increases the number of mosquito-associated viruses known from Finland and presents the northern-most mosquito-associated viruses in Europe to date.

In this work, we report the detection of a novel single-strand RNA virus from wheat, tentatively named \"Triticum aestivum-associated virga-like virus 1\" (TaAVLV1). Further characterization revealed that the complete genome of TaAVLV1 is divided into two segments, RNA1 and RNA2, which are 3530 and 3466 nt in length, excluding their respective polyA tails, and each contains only one open reading frame (ORF). The ORF of RNA1 encodes an RNA-dependent RNA polymerase (RdRp), while the ORF of RNA2 encodes a putative protein with methyltransferase and helicase domains. Phylogenetic analysis showed that the RdRp of TaAVLV1 is closely related to those of members of the unclassified virga-like virus group in the family Virgaviridae. Thus, we have identified TaAVLV1 as a putative novel virga-like virus belonging to the family Virgaviridae.

Viruses are the causal agent of some of the most limiting diseases in Rubus crops. In this regard, a detailed knowledge of the Rubus virome is essential for successfully implementing mitigation strategies and assessing the risk of the emergence of novel viral diseases. Fortunately, the widespread use of RNA sequencing to characterize diverse aspects of the biology of Rubus species can also be a valuable source of data on viruses associated with these hosts. Here, we present a meta-analysis of the Rubus virome based on the re-examination of public RNAseq data from nine Rubus species and 23 hybrid cultivars worldwide. As a result, we identified 23 viruses and one viroid associated with the genus Rubus. Detected viruses are part of eleven families and 26 genera. We also provide evidence of a second species in the genus Brambyvirus, and a novel member of the family Virgaviridae. Our data also revealed raspberry bushy dwarf virus (RBDV) to be the most prevalent and generalist Rubus virus. With respect to the number of species, the genus Ilarvirus and the family Closteroviridae were the most diverse taxonomic ranks affecting Rubus. Network analysis revealed distinct Rubus viromes in different countries and analysis of coinfections revealed three main viral communities infecting these plant species across the world. We also provide information on virus variants from new locations worldwide and data on potential emergent viruses from other plant hosts.

Potato mop-top virus (PMTV) is considered an emerging threat to potato production in the United States. PMTV is transmitted by a soil-borne protist, Spongospora subterranean . Rapid, accurate, and sensitive detection of PMTV in leaves and tubers is an essential component in PMTV management program. A rapid test that can be adapted to in-field, on-site testing with minimal sample manipulation could help in ensuring the sanitary status of the produce in situations such as certification programs and shipping point inspections. Toward that goal, a rapid and highly sensitive recombinase polymerase amplification (RPA)-based test was developed for PMTV detection in potato tubers. The test combines the convenience of RPA assay with a simple sample extraction procedure, making it amenable to rapid on-site diagnosis of PMTV. Furthermore, the assay was duplexed with a plant internal control to monitor sample extraction and RPA reaction performance. The method described could detect as little as 10 fg of PMTV RNA transcript in various potato tissues, the diagnostic limit of detection (LOQ) similar to that of traditional molecular methods.

BackgroundThe Jerusalem sage (Phlomis fruticosa) is a popular ornamental in Europe. In 2022, typical virus-like symptoms consisting of chlorotic rings and irregular patches were identified on leaves of this plant species in Lausanne, Switzerland.MethodsHigh-throughput sequencing was used on symptomatic samples, which was followed by transmission electron microscopy, sap inoculations of indicator species, and RT-PCR analyses.ResultsTwo RNA viruses were identified. The first one represents a novel isolate of tobacco rattle virus (TRV) named “Phlo”. Its presence was confirmed in symptomatic plants but not in asymptomatic ones. Phlo is distinguished by its exceptionally long RNA2 that harbours a peculiar genetic make-up, which could be associated with host-specific systemic infection ability. The second virus, detected both in symptomatic and asymptomatic sages, is a novel member of the family Phenuiviridae named “phlomis phenuivirus 1” (PPV1). PPV1 exhibits a “cogu-like” architecture with a bi-segmented, ambisense RNA genome encoding a replicase, nucleocapsid, and putative movement protein. PPV1 is related to muscari virus A, and together they likely constitute a new genus for which the name “Maladivirus” is proposed.ConclusionsTRV Phlo is most likely responsible for the symptoms observed on the Jerusalem sages. PPV1 may be latent on this species, although there are still uncertainties regarding its host.

Objectives. Culex pipiens mosquitoes are the vectors of West Nile virus (WNV) in Romania. Usutu virus - an emergent zoonotic mosquito-borne pathogen causing mortality in birds - was also detected in Cx. pipiens from Bucharest. Metavirome analysis conducted on vector populations facilitates the understanding of the wide diversity and abundance of arboviruses and insect-specific viruses (ISVs). This high-throughput sequencing study aimed to characterise the RNA metavirome of Cx. pipiens collected in Bucharest. Materials and methods. Female mosquito pools positive for WNV and collected in 2023 (2) and 2024 (9) were selected for analysis. RNA extracted from mosquito pool homogenates was used for metagenomic library preparation with Nextera XT and sequencing was performed on a MiSeq or NovaSeq 6000 system (Illumina). The resulting data were analysed using open-access platforms. Results and discussion. The most abundant RNA viruses detected are not yet classified at genus/family level (Hubei virga-like virus 2, Hubei mosquito virus 4, Culex Bunya-like virus, Culex Bunyavirus 2, Culex mononega-like virus 1, Culex negev-like virus 1, Anjon virus, Serbia picornalike virus 1, Culex associated luteo-like virus). Members of negative-sense single-stranded RNA virus families (Peribunyaviridae, Rhabdoviridae, Phasmaviridae, and Orthomyxoviridae), positivesense single-stranded RNA virus families (Flaviviridae, Virgaviridae, Iflaviridae, Nodaviridae, Luteoviridae, Picornaviridae, Solemoviridae, and Dicistroviridae), and double-stranded RNA virus families (Chrysoviridae and Totiviridae) were detected also. Whole genome sequences of WNV were recovered from seven samples. Phylogenetic analysis indicated lineage 2a. Conclusions. The role of the identified ISVs is unknown. It is speculated that they can modulate the transmission of human viral pathogens by interfering with replication, or that they represent the evolutionary basis for viruses of medical significance. Funding source: This work was carried in the frame of the Core Program within the National Research Development and Innovation Plan 2022-2027, carried out with the support of MCID, project no. 23 44.

Here, we report the complete genome sequence and organization of a novel virus detected in rubber trees (Hevea brasiliensis). Because the infected plants were asymptomatic, this virus was tentatively named \"rubber tree latent virus 1\" (RTLV1). The full genome of RTLV1 is 9,422 nt in length and contains three open reading frames with a 157-nt 5' untranslated region (UTR) and a 316-nt 3' UTR. The replicase shares the highest amino acid (aa) sequence identity (32.62%), with only 31% query coverage, with the replicase of Hubei virga-like virus 11. Phylogenetic analysis based on the aa sequence of ORF1 showed that RTLV1 clustered with unclassified members of the family Virgaviridae in a clade that was not closely related to any genus in this family.