Double stranded cDNA of cucumber pale fruit viroid (CPFV) has been cloned by the method of Okayama and Berg (Mol.Cell.Biol.2,161-170 (1982)) and the complete nucleotide sequence was established. The covalently closed circular molecules of single-stranded CPFV RNA consists of 303 nucleotides. The nucleotide sequence of CPFV was compared with the previously established sequence of hop stunt viroi...

Viroids are autonomously replicating, small singlestranded circular RNA molecules that do not code for proteins and may cause disease in infected, susceptible plants. Viroids have the ability to induce both RNA-mediated transcriptional gene silencing (TGS) and posttranscriptional gene silencing (PTGS) in infected plants. Viroid PTGS has also been demonstrated in a wheat germ extract system. A p...

Extensive simple sequence repeat (SSR) surveys have been performed for eukaryotic prokaryotic and viral genomes, but information regarding SSRs in viroids is limited. We undertook a survey to examine the presence of SSRs in viroid genomes. Our results show that the distribution of SSRs in viroids may influence secondary structure, and that SSRs could play a role in generating genetic diversity....

Nucleic acids isolated from uninfected and potato spindle tuber viroid-infected Rutgers tomato plants were fractionated on agarose gels under two different sets of denaturing conditions and hybridized to (125)I-labeled viroid in a series of blot hybridization experiments. Complementary strand nucleic acids detected in extracts of infected plants were heterogeneous in size, with four discrete ba...

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...