Two Novel Betarhabdovirins Infecting Ornamental Plants and the Peculiar Intracellular Behavior of the Cytorhabdovirus in the Liana .

Two novel members of the subfamily , family were identified in Brazil. Overall, their genomes have the typical organization 3'-' observed in mono-segmented plant-infecting rhabdoviruses. In aristolochia-associated cytorhabdovirus (AaCV), found in the liana aristolochia ( Hook), an additional short orphan ORF encoding a transmembrane helix was detected between and .

Conserved untranslated regions of multipartite viruses: Natural markers of novel viral genomic components and tags of viral evolution.

Viruses with split genomes are classified as being either segmented or multipartite based on whether their genomic segments occur within a single virion or across different virions. Despite variations in number and sequence during evolution, the genomic segments of many viruses are conserved within the untranslated regions (UTRs). In this study, we present a methodology that combines RNA sequencing with iterative BLASTn of UTRs (https://github.

Kitaviruses: A Window to Atypical Plant Viruses Causing Nonsystemic Diseases.

is a family of plant-infecting viruses that have multiple positive-sense, single-stranded RNA genomic segments. Kitaviruses are assigned into the genera , , and , mainly on the basis of the diversity of their genomic organization. Cell-to-cell movement of most kitaviruses is provided by the 30K family of proteins or the binary movement block, considered an alternative movement module among plant viruses.

Citrus Bright Spot Virus: A New Dichorhavirus, Transmitted by , Causing Citrus Leprosis Disease in Brazil.

Citrus leprosis (CL) is the main viral disease affecting the Brazilian citriculture. Sweet orange ( L. Osbeck) trees affected by CL were identified in small orchards in Southern Brazil.

ICTV Virus Taxonomy Profile: 2022.

The family comprises viruses with negative-sense (-) RNA genomes of 10-16 kb. Virions are typically enveloped with bullet-shaped or bacilliform morphology but can also be non-enveloped filaments. Rhabdoviruses infect plants or animals, including mammals, birds, reptiles, amphibians or fish, as well as arthropods, which serve as single hosts or act as biological vectors for transmission to animals or plants.

Circulative Transmission of Cileviruses in Mites May Involve the Paracellular Movement of Virions.

Plant viruses transmitted by mites of the genus are members of the genera , family , or , family . They produce non-systemic infections that typically display necrotic and/or chlorotic lesions around the inoculation loci. The cilevirus citrus leprosis virus C (CiLV-C) causes citrus leprosis, rated as one of the most destructive diseases affecting this crop in the Americas.

A Novel Lineage of Cile-Like Viruses Discloses the Phylogenetic Continuum Across the Family .

An increasing number of plant species have been recognized or considered likely reservoirs of viruses transmitted by mites. A tiny fraction of these viruses, primarily those causing severe economic burden to prominent crops, have been fully characterized. In this study, based on high-throughput sequencing, transmission electron microscopy analyses of virions in plant-infected tissues, viral transmission experiments, and the morphoanatomical identification of the involved mites, we describe molecular and biological features of viruses representing three new tentative species of the family .

Spontaneous Mutation in the Movement Protein of Citrus Leprosis Virus C2, in a Heterologous Virus Infection Context, Increases Cell-to-Cell Transport and Generates Fitness Advantage.

Previous results using a movement defective alfalfa mosaic virus (AMV) vector revealed that citrus leprosis virus C (CiLV-C) movement protein (MP) generates a more efficient local movement, but not more systemic transport, than citrus leprosis virus C2 (CiLV-C2) MP, MPs belonging to two important viruses for the citrus industry. Here, competition experiment assays in transgenic tobacco plants (P12) between transcripts of AMV constructs expressing the cilevirus MPs, followed by several biological passages, showed the prevalence of the AMV construct carrying the CiLV-C2 MP. The analysis of AMV RNA 3 progeny recovered from P12 plant at the second viral passage revealed the presence of a mix of progeny encompassing the CiLV-C2 MP wild type (MP) and two variants carrying serines instead phenylalanines at positions 72 (MP) or 259 (MP), respectively.

Poorly Conserved P15 Proteins of Cileviruses Retain Elements of Common Ancestry and Putative Functionality: A Theoretical Assessment on the Evolution of Cilevirus Genomes.

The genus groups enveloped single-stranded (+) RNA virus members of the family , order . Proteins P15, scarcely conserved polypeptides encoded by cileviruses, have no apparent homologs in public databases. Accordingly, the open reading frames (ORFs) , located at the 5'-end of the viral RNA2 molecules, are considered orphan genes (ORFans).

Molecular Epidemiology of Citrus Leprosis Virus C: A New Viral Lineage and Phylodynamic of the Main Viral Subpopulations in the Americas.

Despite the importance of viral strains/variants as agents of emerging diseases, genetic and evolutionary processes affecting their ecology are not fully understood. To get insight into this topic, we assessed the population and spatial dynamic parameters of citrus leprosis virus C (CiLV-C, genus , family ). CiLV-C is the etiological agent of citrus leprosis disease, a non-systemic infection considered the main viral disorder affecting citrus orchards in Brazil.

First detection of orchid fleck virus in orchids in Mexico.

For the first time, an isolate of the dichorhavirus orchid fleck virus (OFV, family ) was found infecting an orchid plant in Mexico. The infected sample of was collected in a nursery in Lagunillas, municipality of Zihuateutla, Edo. Puebla.

Joá yellow blotch-associated virus, a new alphanucleorhabdovirus from a wild solanaceous plant in Brazil.

We identified a novel plant rhabdovirus infecting native joá (Solanum aculeatissimum) plants in Brazil. Infected plants showed yellow blotches on the leaves, and typical enveloped bacilliform rhabdovirus particles associated with the nucleus were seen in thin sections by electron microscopy. The virus could be graft-transmitted to healthy joá and tomato plants but was not mechanically transmissible.

Membrane Association and Topology of Citrus Leprosis Virus C2 Movement and Capsid Proteins.

Although citrus leprosis disease has been known for more than a hundred years, one of its causal agents, citrus leprosis virus C2 (CiLV-C2), is poorly characterized. This study described the association of CiLV-C2 movement protein (MP) and capsid protein (p29) with biological membranes. Our findings obtained by computer predictions, chemical treatments after membrane fractionation, and biomolecular fluorescence complementation assays revealed that p29 is peripherally associated, while the MP is integrally bound to the cell membranes.

Unravelling the involvement of cilevirus p32 protein in the viral transport.

Citrus leprosis (CL) is a severe disease that affects citrus orchards mainly in Latin America. It is caused by Brevipalpus-transmitted viruses from genera Cilevirus and Dichorhavirus. Currently, no reports have explored the movement machinery for the cilevirus.

Dichorhaviruses Movement Protein and Nucleoprotein Form a Protein Complex That May Be Required for Virus Spread and Interacts With Viral Movement-Related Cilevirus Proteins.

-transmitted viruses (BTVs) belong to the genera and and are the main causal agents of the citrus leprosis (CL) disease. In this report, we explored aspects related to the movement mechanism mediated by dichorhaviruses movement proteins (MPs) and the homologous and heterologous interactions among viral proteins related to the movement of citrus leprosis-associated viruses. The membrane-spanning property and topology analysis of the nucleocapsid (N) and MP proteins from two dichorhaviruses revealed that the MPs are proteins tightly associated with the cell membrane, exposing their N- and C-termini to the cytoplasm and the inner part of the nucleus, whereas the N proteins are not membrane-associated.

Survey of the citrus leprosis vector (Brevipalpus yothersi) and phytoseiids in spontaneous plants of an organic citrus orchard.

Citrus leprosis (CL) is one of the most important viral diseases in sweet orange orchards in Latin America. It is caused by members of at least five species of the so-called Brevipalpus-transmitted viruses (BTV), and the prevalent is Citrus leprosis virus C (CiLV-C). This virus has the broadest host range amongst all CL-associated viruses and is transmitted by Brevipalpus yothersi, a polyphagous mite that can colonize a large variety of host plants, including some spontaneous ground cover plants.