viroids are smallest, single-stranded, circular, highly structured plant pathogenic rnas that do not code for any protein. viroids belong to two families, the avsunviroidae and the pospiviroidae. members of the pospiviroidae family adopt a rod-like secondary structure. in this study the most stable secondary structures of citrus viroid variants that reported from fars province were drawn. the m...

Abstract Citrus exocortis is a grafting disease caused by Exocortis Viroid (CEVd). The knowledge of the viroid’s incidence and distribution are necessary to further apply control measures. objective this work was real time PCR assay for detection CEVd in samples collected from symptomatic CEVd-infected plants Mitidja (North Algeria). showed an excellent diagnostic specificity where 38 out 50 po...

A 23-kD pathogenesis-related protein (P23) is induced in tomato (Lycopersicon esculentum Mill, cv Rutgers) plants when infected with citrus exocortis viroid. This protein is homologous to the salt-induced tomato NP24 protein (I. Rodrigo, P. Vera, R. Frank, V. Conejero [1991] Plant Mol Biol 16: 931-934). Further characterization of P23 has shown that this protein accumulates in vacuoles in assoc...

Like many plant RNA viruses, infection by potato spindle tuber viroid (PSTVd) is known to lead to RNA silencing and a marked reduction in visible disease. To examine the relationship between RNA silencing and this recovery phenomenon in greater detail, we have carried out time-course analyses of viroid-specific small RNA accumulation using several viroid—host combinations. These analyses reveal...

Citrus are affected by many viruses and viroids, some globally widespread restricted to particular countries or areas. In this study, we simulated the use of high throughput sequencing (HTS) bioinformatic analysis small interfering RNAs (siRNA) as a pre-screening method guide bioindexing molecular detection enhance surveillance survey key emerging citrus viruses, such non-European tristeza viru...

A graft-transmissible disease displaying red veins, red blotches and total reddening of leaves in red-berried wine grape (Vitis vinifera L.) cultivars was observed in commercial vineyards. Next-generation sequencing technology was used to identify etiological agent(s) associated with this emerging disease, designated as grapevine redleaf disease (GRD). High quality RNA extracted from leaves of ...

Hop stunt viroid (HSVd) is able to infect a number of herbaceous and woody hosts, such as grapevine, Citrus or Prunus plants. Previous phylogenetic analyses have suggested the existence of three major groups of HSVd isolates (plum-type, hop-type and citrus-type). The fact that these groups often contain isolates from only a limited number of isolation hosts prompted the suggestion that group-di...

Abstract Hop stunt viroid (HSVd) and Citrus tristeza virus (CTV) are the causal agents of most important diseases of citrus. Previously we reported a novel variant of HSVd that constantly associated with the yellow corky vein disease. Here, 19 individual citrus leaves with yellow corky vein symptoms were sampled for CTV by ELISA. In this study, most symptomatic samples were found to be inf...