2 research outputs found
Dahlia latent viroid: a recombinant new species of the family Pospiviroidae posing intriguing questions about its origin and classification
[EN] A viroid-like RNA has been detected in two asymptomatic dahlia accessions by return and double
PAGE. It appeared smaller than Chrysanthemum stunt viroid and Potato spindle tuber viroid, the
two members of the genus Pospiviroid, family Pospiviroidae, reported in this ornamental
previously. RT-PCR with primers designed for amplifying all pospiviroids produced no amplicons,
but RT-PCR with random primers revealed a 342 nt RNA. The sequence of this RNA was
confirmed with specific primers, which additionally revealed its presence in many dahlia cultivars.
The RNA was named Dahlia latent viroid (DLVd) because it replicates autonomously, but
symptomlessly, in dahlia and shares maximum sequence identity with other viroids of less than
56 %. Furthermore, DLVd displays characteristic features of the family Pospiviroidae: a predicted
rod-like secondary structure of minimum free energy with a central conserved region (CCR), and
the ability to form the metastable structures hairpins I and II. Its CCR is identical to that of Hop
stunt viroid (HSVd, genus Hostuviroid). However, DLVd: (i) has the terminal conserved region
present in members of the genus Pospiviroid, but absent in HSVd, and (ii) lacks the terminal
conserved hairpin present in HSVd. Phylogenetic reconstructions indicate that HSVd and Pepper
chat fruit viroid (genus Pospiviroid) are the closest relatives of DLVd, but DLVd differs from these
viroids in its host range, restricted to dahlia so far. Therefore, while DLVd fulfils the criteria to be a
novel species of the family Pospiviroidae, its recombinant origin makes assignment to the genera
Pospiviroid or Hostuviroid problematicResearch in R. F.'s laboratory is presently supported from the Ministerio de Educacion y Ciencia (MEC) of Spain by grant BFU2011-28443. During this work P. S. has been supported by postdoctoral contracts from the Generalitat Valenciana (APOSTD/2010, program VALi + d) and the MEC (Program Juan de la Cierva).Verhoeven, JTJ.; Meekes, ETM.; Roenhorst, JW.; Flores Pedauye, R.; Serra Alfonso, P. (2013). Dahlia latent viroid: a recombinant new species of the family Pospiviroidae posing intriguing questions about its origin and classification. Journal of General Virology. 94(4):711-719. https://doi.org/10.1099/vir.0.048751-0S71171994