Highly purified isolates of potato spindle tuber viroid (PSTV) from Lycopersicon esculentum cv. Rutgers and citrus exocortis viroid (CEV) from Gynura aurantiaca have been compared. Two-dimensional fingerprinting analysis of PSTVand CEV-RNA labeled in vitro with lzrI has demonstrated that (i) each of these RNA species has a complexity compatible with the size estimate of 250X350 nucleotides and ...

in this study, the possible infection of thomson navel, moro blood sweet orange, page mandarin and webber pomelo with citrus viroids was investigated. biological indexing was performed by grafting on etrog citron (c. medica) and maintained in temperature-controlled greenhouse. after inoculation, rna was extracted by sds– potassium acetate method. detection of citrus viroids was done reverse tra...

Here, we report complete genome sequences of grapevine yellow speckle viroid 1 (GYSVd1) and hop stunt viroid (HSVd), members of the family Pospiviroidae, assembled from the transcriptome data generated from Ixeridium dentatum plants. To our knowledge, this is the first report of GYSVd1 and HSVd in I. dentatum.

A single stranded circular RNA was isolated from grapevines infected with yellow speckle disease. The RNA which we have called grapevine yellow speckle viroid (GYSV), contains 367 nucleotide residues and has the potential to form the rod-like secondary structure characteristic of viroids. GYSV has 37% sequence homology with the recently described apple scar skin viroid (ASSV; 330 residues) and ...

BACKGROUND Viroids are the smallest pathogens of plants. To date the structural and conformational details of the cleavage of Avocado sunblotch viroid (ASBVd) and the catalytic role of Mg2+ ions in efficient self-cleavage are of crucial interest. RESULTS We report the first Raman characterization of the structure and activity of ASBVd, for plus and minus viroid strands. Both strands exhibit a...

plant samples were collected from yazd, isfahan, fars and tehran provinces and examined for their possible infection by hop stunt viroid (hsvd). the experimental host range of the viroid was determined by injection of infected sap into greenhouse grown seedlings and subsequent assay of inoculated plants by rt-pcr. fig, mulberry and citrus isolates of the viroid were compared with respect to hos...

Viroids are uncoated infectious RNA molecules (MW 107 OOO127 000) known as pathogens of certain higher plants. Thermodynamic and kinetic studies were carried out on highly purified viroid preparations by applying UV-absorption melting analysis and temperature jump methods. The thermal denaturation of viroids is characterized by high thermal stability, high cooperativlty and a high degree of bas...

We identified conditions for heating and quick cooling viroid RNAs in the presence of salt which lead to the production of conformational isomers stable to incubation for at least 45 minutes at 30 degrees in the presence of magnesium ions. Elution in 0.3 M NaCl allowed the purification of an electrophoretically slow form of an in vitro transcript carrying a complete copy of the potato spindle t...

Viroids are small self-replicating RNAs that infect plants. How these noncoding pathogenic RNAs interact with hosts to induce disease symptoms is a long-standing unanswered question. Recent experimental data have led to the suggestive proposal of a pathogenic model based on the RNA silencing mechanism. However, evidence of a direct relation between key components of the RNA silencing pathway an...

Abstract Background and Aims: Hop stunt viroid (HSVd, genus Hostuviroid, family Pospiviroidae) has a wide host range among trees and herbaceous plants. The objectives of this study were to compare biological and physical characteristics of three isolates of HSVd from mulberry, fig and citrus and search for other hosts of this viroid in Iran. Materials and Methods: Plant samples were col...