Closteroviruses possess exceptionally long filamentous virus particles that mediate protection and active transport of the genomic RNA within infected plants. These virions are composed of a long "body" and short "tail" whose principal components are the major and minor capsid proteins, respectively. Here we use biochemical, genetic, and ultrastructural analyses to dissect the molecular composi...

Deep sequencing analysis of an asymptomatic grapevine revealed a virome containing five RNA viruses and a viroid. Of these, Grapevine leafroll-associated virus 7 (GLRaV-7), an unassigned closterovirus, was by far the most prominently represented sequence in the analysis. Graft-inoculation of the infection to another grape variety confirmed the lack of the leafroll disease symptoms, even though ...

Introduction The presence of double stranded RNA (dsRNA) in virus-infected tissue has been well documented by Morris and Dodds (4), Dodds and Bar-Joseph (2). The analysis of dsRNA proved to be useful for determining the virus-free status of propagation material after sanitation treatments. Isolated directly from grapevine, dsRNA is also a good source of viral RNA for synthesizing and cloning cD...

Computer-assisted analysis revealed a striking sequence similarity between the putative 24-kDa protein (p24) encoded by open reading frame (ORF) 5 of beet yellows closterovirus and the coat protein of this virus encoded by the adjacent ORF6. Both of these proteins are closely related to the homologous proteins of another closterovirus, citrus tristeza virus. It is hypothesized that the genes fo...

In eukaryotic virus systems, infection leads to induction of membranous compartments in which replication occurs. Virus-encoded subunits of the replication complex mediate its interaction with membranes. As replication platforms, RNA viruses use the cytoplasmic surfaces of different membrane compartments, e.g., endoplasmic reticulum (ER), Golgi, endo/lysosomes, mitochondria, chloroplasts, and p...

The genome of pineapple mealybug wilt-associated closterovirus-2 (PMWaV-2) was cloned from double-stranded RNA isolated from diseased pineapple and its sequence determined. The 3'-terminal 14861 nt of the single-stranded RNA genome contains ten open reading frames (ORFs) which, from 5' to 3', potentially encode a >204 kDa polyprotein containing papain-like protease, methyltransferase and helica...

Common green ti plants (Cordyline fruticosa L.) in Hawaii can be infected by four recently characterized closteroviruses that are tentative members of the proposed genus Velarivirus. In this study, a reverse-transcription polymerase chain reaction (RT-PCR) assay developed to detect and distinguish Cordyline virus 1 (CoV-1), CoV-2, CoV-3, and CoV-4 was used to determine: (i) the distribution of ...

The large RNA genome of Citrus tristeza virus (CTV; ca. 20 kb) contains 12 open reading frames, with the 3'-terminal one corresponding to a protein of 209 amino acids (p23) that is expressed from an abundant subgenomic RNA. p23, an RNA-binding protein with a putative zinc-finger domain and some basic motifs, is unique to CTV because no homologs have been found in other closteroviruses, includin...