title: Artificial microRNAs and synthetic trans-acting small interfering RNAs interfere with viroid infection.
abstract: Artificial microRNAs (amiRNAs) and synthetic trans-acting small interfering RNAs (syn-tasiRNAs) are two classes of artificial small RNAs (sRNAs) engineered to silence endogenous transcripts as well as viral RNAs in plants. Here, we explore the possibility of using amiRNAs and syn-tasiRNAs to specifically interfere with infections by viroids, small (250-400-nucleotide) non-coding circular RNAs with compact secondary structure infecting a wide range of plant species. The combined use of recent high-throughput methods for artificial sRNA construct generation and the Potato spindle tuber viroid (PSTVd)-Nicotiana benthamiana pathosystem allowed for the simple and time-effective screening of multiple artificial sRNAs targeting sites distributed along PSTVd RNAs of (+) or (-) polarity. The majority of amiRNAs were highly active in agroinfiltrated leaves when co-expressed with an infectious PSTVd transcript, as were syn-tasiRNAs derived from a construct including the five most effective amiRNA sequences. A comparative analysis showed that the effects of the most effective amiRNA and of the syn-tasiRNAs were similar in agroinfiltrated leaves, as well as in upper non-agroinfiltrated leaves in which PSTVd accumulation was significantly delayed. These results suggest that amiRNAs and syn-tasiRNAs can be used effectively to control viroid infections in plants.
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia, 46022, Spain.
authors.forename: Alberto
authors.identifier: 0000-0001-5628-6632
authors.initials: A
authors.lastname: Carbonell
authors.affiliation: Instituto de Biología Molecular y Celular de Plantas (Consejo Superior de Investigaciones Científicas-Universidad Politécnica de Valencia), Valencia, 46022, Spain.
authors.forename: José-Antonio
authors.identifier: 0000-0002-6535-2889
authors.initials: JA
authors.lastname: Daròs
mesh_terms: D035683:MicroRNAs / Q000235:genetics*; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D014026:Nicotiana / Q000235:genetics / Q000821:virology; D014772:Viroids / Q000235:genetics / Q000472:pathogenicity*
chemical_list: D035683:MicroRNAs; D034741:RNA, Small Interfering; D012367:RNA, Viral
keywords: PSTVd; RNA silencing; artificial microRNA; pathogen resistance; small RNA; synthetic trans-acting siRNA; viroid