Citrus viroid V: Molecular characterization and synergistic interactions with other members of the genus Apscaviroid

Abstract

Studies on Atalantia citroides, a citrus relative, revealed the existence of a viroid not described previously. The new viroid has a GC-rich genome of 293-294 nucleotides and contains the central conserved region characteristic of members of the genus Apscaviroid, and the terminal conserved region present in this and other genera of the family Pospiviroidae. The secondary structure of minimum free energy predicted for the new viroid is a rod-like conformation with 68.7% paired nucleotides and showing sequence identities with other viroids always lower than 90%, the conventional limit that separates different species within a given genus. Infectivity assays showed that the new viroid induces mild but characteristic symptoms on the indicator Etrog citron. Co-inoculation of CVd-V with either Citrus bent leaf viroid or Citrus viroid III, two other members of the genus Apscaviroid infecting citrus, disclosed synergistic interactions manifested in enhanced leaf symptoms and very pronounced dwarfing. Viroid titers, however, remained unaltered in co-infected plants. Possible mechanisms underlying the observed synergistic effects are discussed. According to its molecular and biological properties and its unusual ability to replicate in A. citroides, the new viroid, tentatively named Citrus viroid V (CVd-V), should be considered a new species of the genus Apscaviroid.

The Detection and Diagnosis Methods of Infectious Viroids caused Plant Diseases

“…바이로이드가 주로 감염되는 숙주로는 사과, 배, 포도, 토마 토, 감자, 시트러스, 국화, 코코넛 팜, 아보카도, 홉 등이 있다 [58]. 주로 야기되는 바이로이드는 Pospiviroidae과의 Apple scar skin viroid (ASSVd) [46], Pear blister canker viroid (PBCVd) [24], Citrus bent leaf viroid (CVd-Ib) [63], Citrus exocortis viroid (CEVd) [68], Hop stunt viroid (HSVd) [36], Coconut cadang-cadang viroid (CCCVd) [79], Potato spindle tuber viroid (PSDVd) [67], Coleus blumei viroid 1 (CbVd) [1], Avsunviroidae과의 Avocado sunblotch Viroid (ASVd) [10], Peach latent mosaic viroid (PLMVd) [29], Eggplant latent viroid (ELVd) [14] 등이 있다( Table 1).…”

Resistencia a viroides inducida por ribozimas de cabeza de martillo y RNAs interferentes

“…Para cada especie se indica la abreviatura de su nombre en inglés (junto con el nombre en castellano entre paréntesis), el tamaño en nucleótidos de la variante típica, y la referencia de la publicación en donde se describió su estructura molecular. Además, otros tres viroides de los cítricos [el viroide I-LSS (CVd-I-LSS, Ito et al, 2000), el viroide OS (CVd-OS, Ito et al, 2001) y el viroide V (CVd-V, Serra et al, 2008)] han sido propuestos como miembros del género Apscaviroid.…”

DETECCIÓN Y CARACTERIZACIÓN AGRONÓMICA DE VIROIDES DE CÍTRICOS. IDENTIFICACIÓN Y CARACTERIZACIÓN MOLECULAR Y BIOLOGÍCA DE VARIANTES DEL VIROIDE DEL ENANISMO DE LOS CÍTRICOS CDVd.

“…En la Tabla 3 se presentan tanto los viroides de cítricos incluidos en el presente sistema de taxonómico de la ICTV, como otros dos viroides, CVd-OS y CVd-V , Serra et al, 2008b, que conforman un conjunto de siete viroides distintos en cítricos. , Reanwarakorn y Semancik, 1998Palacio-Bielsa et al, 2004;Serra et al, 2008a) …”

“…Se desconoce su origen, y probablemente pasó desapercibido en anteriores análisis por sPAGE debido a que presenta una movilidad electroforética similar a HSVd y CDVd (Barbosa et al, 2005, Duran-Vila et al, 1993. Después de su reciente caracterización molecular y biológica se ha propuesto como una nueva especie del genero Apscaviroid dentro de la familia Pospiviroidae (Serra et al, 2008b). Este nuevo viroide tiene un genoma de 293-294 nucleótidos y contiene la CCR y la TCR típicas de los miembros del género Apscaviroid.…”

“…Subsequently, with the development of a double electrophoresis system (sequential polyacrylamide gel electrophoresis, sPAGE), a number of circular RNAs with faster migration than CEVd were consistently identified in field isolates, and their viroid nature established by infectivity assays on Etrog citron . These viroids initially termed "citrus viroids (CVd)" were classified into five groups based on their electrophoretic migration in 5% sPAGE, sequence similarity determined by molecular hybridization against specific cDNA probes and host specific symptoms on the Etrog citron indicator Citrus viroid OS (CVd-OS) and Citrus viroid V (CVd-V) have been reported Serra et al, 2007).…”