Citrus tristeza virus (CTV, genus Closterovirus, family Closteroviridae) is the largest member of its taxonomic family. Viral particles, 2000 nm in length and 10–12 nm in diameter, are present in the phloem of infected plants. A single stranded positive sense RNA molecule approximately 20,000 nucleotides long constitutes its genome (BarBacterial expressed coat protein: development of a single a...

A device and improved method based on the use of a compartmentalized Eppendorf tube that allows capture, reverse transcription and nested-PCR in a single closed-tube has been developed and patented. The main advantages of the system are the high sensitivity obtained, the simplicity, the low risk of contamination and the easy establishment of adequate conditions for nested-PCR. The method has be...

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...

Chlorotic fleck, a strawberry disease caused by a graft and aphid transmissible agent, was identified more than 45 years ago in Louisiana. Since its discovery there has been no additional information on the agent that causes the disease. The mode of transmission implies that a virus is the causal agent of chlorotic fleck. We identified four closteroviruses in the single chlorotic fleck infected...

Citrus tristeza is one of the most destructive citrus diseases and is caused by the phloem-restricted Closterovirus, Citrus tristeza virus. Mild strain CTV-B2 does not cause obvious symptoms on indicators whereas severe strain CTV-B6 causes symptoms, including stem pitting, cupping, yellowing, and stiffening of leaves, and vein corking. Our laboratory has previously characterized changes in tra...

Abstract Citrus tristeza virus (CTV) is found worldwide wherever citrus cultivated, causing disease resulting in significant yield losses and sometimes the death of plant. Transgenic plants encoding CTV gene sequences have shown to exhibit pathogen-derived resistance CTV. Exogenous application double-stranded RNA (dsRNA) an established strategy for plant control, making this method attractive a...

Citrus tristeza virus (CTV) (genus Closterovirus, family Closteroviridae) causes some of the more important viral diseases of citrus worldwide. The ability to map disease-inducing determinants of CTV is needed to develop better diagnostic and disease control procedures. A distinctive phenotype of some isolates of CTV is the ability to induce seedling yellows (SY) in sour orange, lemon and grape...

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...