A pospiviroid from symptomless portulaca plants closely related to iresine viroid 1

[EN] In symptomless plants of portulaca a potential new pospiviroid was characterized. Analysis by both double and return PAGE showed the presence of a circular RNA. RT-PCR and sequencing revealed a genome of 351 nt with properties characteristic of members of the genus Pospiviroid and with highest sequence identity (circa 80%) with iresine viroid 1 (IrVd-1). The circular RNA from portulaca was shown to replicate independently in its original host, thus showing that it is indeed a viroid. Based on its molecular characteristics, it should be considered a new species. However, since no biological differences have yet been found with its closest relative IrVd-1, the viroid from portulaca does not fulfil all criteria for species demarcation of the ICTV. © 2015 Elsevier B.V. All rights reserved.Work in R.F. laboratory has been funded by grants BFU2011-28443 and BFU2014-56812-P from Ministerio de Economia y Competititvidad (MINECO, Spain) and ACOMP/2014/A/103 from Generalitat Valenciana (GV). P.S. has been supported by post-doctoral contracts from GV (APOSTD/2010, program VALi+d) and MINECO (program Juan de la Cierva).Verhoeven, JJ.; Roenhorst, J.; Hooftman, M.; Meekes, E.; Flores Pedauye, R.; Serra Alfonso, P. (2015). A pospiviroid from symptomless portulaca plants closely related to iresine viroid 1. Virus Research. 205:22-26. doi:10.1016/j.virusres.2015.05.005S222620